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Sample records for sample study reveals

  1. Monolith Chromatography as Sample Preparation Step in Virome Studies of Water Samples.

    Science.gov (United States)

    Gutiérrez-Aguirre, Ion; Kutnjak, Denis; Rački, Nejc; Rupar, Matevž; Ravnikar, Maja

    2018-01-01

    Viruses exist in aquatic media and many of them use this media as transmission route. Next-generation sequencing (NGS) technologies have opened new doors in virus research, allowing also to reveal a hidden diversity of viral species in aquatic environments. Not surprisingly, many of the newly discovered viruses are found in environmental fresh and marine waters. One of the problems in virome research can be the low amount of viral nucleic acids present in the sample in contrast to the background ones (host, eukaryotic, prokaryotic, environmental). Therefore, virus enrichment prior to NGS is necessary in many cases. In water samples, an added problem resides in the low concentration of viruses typically present in aquatic media. Different concentration strategies have been used to overcome such limitations. CIM monoliths are a new generation of chromatographic supports that due to their particular structural characteristics are very efficient in concentration and purification of viruses. In this chapter, we describe the use of CIM monolithic chromatography for sample preparation step in NGS studies targeting viruses in fresh or marine water. The step-by-step protocol will include a case study where CIM concentration was used to study the virome of a wastewater sample using NGS.

  2. Repeat synoptic sampling reveals drivers of change in carbon and nutrient chemistry of Arctic catchments

    Science.gov (United States)

    Zarnetske, J. P.; Abbott, B. W.; Bowden, W. B.; Iannucci, F.; Griffin, N.; Parker, S.; Pinay, G.; Aanderud, Z.

    2017-12-01

    Dissolved organic carbon (DOC), nutrients, and other solute concentrations are increasing in rivers across the Arctic. Two hypotheses have been proposed to explain these trends: 1. distributed, top-down permafrost degradation, and 2. discrete, point-source delivery of DOC and nutrients from permafrost collapse features (thermokarst). While long-term monitoring at a single station cannot discriminate between these mechanisms, synoptic sampling of multiple points in the stream network could reveal the spatial structure of solute sources. In this context, we sampled carbon and nutrient chemistry three times over two years in 119 subcatchments of three distinct Arctic catchments (North Slope, Alaska). Subcatchments ranged from 0.1 to 80 km2, and included three distinct types of Arctic landscapes - mountainous, tundra, and glacial-lake catchments. We quantified the stability of spatial patterns in synoptic water chemistry and analyzed high-frequency time series from the catchment outlets across the thaw season to identify source areas for DOC, nutrients, and major ions. We found that variance in solute concentrations between subcatchments collapsed at spatial scales between 1 to 20 km2, indicating a continuum of diffuse- and point-source dynamics, depending on solute and catchment characteristics (e.g. reactivity, topography, vegetation, surficial geology). Spatially-distributed mass balance revealed conservative transport of DOC and nitrogen, and indicates there may be strong in-stream retention of phosphorus, providing a network-scale confirmation of previous reach-scale studies in these Arctic catchments. Overall, we present new approaches to analyzing synoptic data for change detection and quantification of ecohydrological mechanisms in ecosystems in the Arctic and beyond.

  3. Multiple surveys employing a new sample-processing protocol reveal the genetic diversity of placozoans in Japan.

    Science.gov (United States)

    Miyazawa, Hideyuki; Nakano, Hiroaki

    2018-03-01

    Placozoans, flat free-living marine invertebrates, possess an extremely simple bauplan lacking neurons and muscle cells and represent one of the earliest-branching metazoan phyla. They are widely distributed from temperate to tropical oceans. Based on mitochondrial 16S rRNA sequences, 19 haplotypes forming seven distinct clades have been reported in placozoans to date. In Japan, placozoans have been found at nine locations, but 16S genotyping has been performed at only two of these locations. Here, we propose a new processing protocol, "ethanol-treated substrate sampling," for collecting placozoans from natural environments. We also report the collection of placozoans from three new locations, the islands of Shikine-jima, Chichi-jima, and Haha-jima, and we present the distribution of the 16S haplotypes of placozoans in Japan. Multiple surveys conducted at multiple locations yielded five haplotypes that were not reported previously, revealing high genetic diversity in Japan, especially at Shimoda and Shikine-jima Island. The observed geographic distribution patterns were different among haplotypes; some were widely distributed, while others were sampled only from a single location. However, samplings conducted on different dates at the same sites yielded different haplotypes, suggesting that placozoans of a given haplotype do not inhabit the same site constantly throughout the year. Continued sampling efforts conducted during all seasons at multiple locations worldwide and the development of molecular markers within the haplotypes are needed to reveal the geographic distribution pattern and dispersal history of placozoans in greater detail.

  4. Transgenic zebrafish reveal tissue-specific differences in estrogen signaling in response to environmental water samples.

    Science.gov (United States)

    Gorelick, Daniel A; Iwanowicz, Luke R; Hung, Alice L; Blazer, Vicki S; Halpern, Marnie E

    2014-04-01

    Environmental endocrine disruptors (EEDs) are exogenous chemicals that mimic endogenous hormones such as estrogens. Previous studies using a zebrafish transgenic reporter demonstrated that the EEDs bisphenol A and genistein preferentially activate estrogen receptors (ERs) in the larval heart compared with the liver. However, it was not known whether the transgenic zebrafish reporter was sensitive enough to detect estrogens from environmental samples, whether environmental estrogens would exhibit tissue-specific effects similar to those of BPA and genistein, or why some compounds preferentially target receptors in the heart. We tested surface water samples using a transgenic zebrafish reporter with tandem estrogen response elements driving green fluorescent protein expression (5xERE:GFP). Reporter activation was colocalized with tissue-specific expression of ER genes by RNA in situ hybridization. We observed selective patterns of ER activation in transgenic fish exposed to river water samples from the Mid-Atlantic United States, with several samples preferentially activating receptors in embryonic and larval heart valves. We discovered that tissue specificity in ER activation was due to differences in the expression of ER subtypes. ERα was expressed in developing heart valves but not in the liver, whereas ERβ2 had the opposite profile. Accordingly, subtype-specific ER agonists activated the reporter in either the heart valves or the liver. The use of 5xERE:GFP transgenic zebrafish revealed an unexpected tissue-specific difference in the response to environmentally relevant estrogenic compounds. Exposure to estrogenic EEDs in utero was associated with adverse health effects, with the potentially unanticipated consequence of targeting developing heart valves.

  5. The Study on Mental Health at Work: Design and sampling.

    Science.gov (United States)

    Rose, Uwe; Schiel, Stefan; Schröder, Helmut; Kleudgen, Martin; Tophoven, Silke; Rauch, Angela; Freude, Gabriele; Müller, Grit

    2017-08-01

    The Study on Mental Health at Work (S-MGA) generates the first nationwide representative survey enabling the exploration of the relationship between working conditions, mental health and functioning. This paper describes the study design, sampling procedures and data collection, and presents a summary of the sample characteristics. S-MGA is a representative study of German employees aged 31-60 years subject to social security contributions. The sample was drawn from the employment register based on a two-stage cluster sampling procedure. Firstly, 206 municipalities were randomly selected from a pool of 12,227 municipalities in Germany. Secondly, 13,590 addresses were drawn from the selected municipalities for the purpose of conducting 4500 face-to-face interviews. The questionnaire covers psychosocial working and employment conditions, measures of mental health, work ability and functioning. Data from personal interviews were combined with employment histories from register data. Descriptive statistics of socio-demographic characteristics and logistic regressions analyses were used for comparing population, gross sample and respondents. In total, 4511 face-to-face interviews were conducted. A test for sampling bias revealed that individuals in older cohorts participated more often, while individuals with an unknown educational level, residing in major cities or with a non-German ethnic background were slightly underrepresented. There is no indication of major deviations in characteristics between the basic population and the sample of respondents. Hence, S-MGA provides representative data for research on work and health, designed as a cohort study with plans to rerun the survey 5 years after the first assessment.

  6. The Study on Mental Health at Work: Design and sampling

    Science.gov (United States)

    Rose, Uwe; Schiel, Stefan; Schröder, Helmut; Kleudgen, Martin; Tophoven, Silke; Rauch, Angela; Freude, Gabriele; Müller, Grit

    2017-01-01

    Aims: The Study on Mental Health at Work (S-MGA) generates the first nationwide representative survey enabling the exploration of the relationship between working conditions, mental health and functioning. This paper describes the study design, sampling procedures and data collection, and presents a summary of the sample characteristics. Methods: S-MGA is a representative study of German employees aged 31–60 years subject to social security contributions. The sample was drawn from the employment register based on a two-stage cluster sampling procedure. Firstly, 206 municipalities were randomly selected from a pool of 12,227 municipalities in Germany. Secondly, 13,590 addresses were drawn from the selected municipalities for the purpose of conducting 4500 face-to-face interviews. The questionnaire covers psychosocial working and employment conditions, measures of mental health, work ability and functioning. Data from personal interviews were combined with employment histories from register data. Descriptive statistics of socio-demographic characteristics and logistic regressions analyses were used for comparing population, gross sample and respondents. Results: In total, 4511 face-to-face interviews were conducted. A test for sampling bias revealed that individuals in older cohorts participated more often, while individuals with an unknown educational level, residing in major cities or with a non-German ethnic background were slightly underrepresented. Conclusions: There is no indication of major deviations in characteristics between the basic population and the sample of respondents. Hence, S-MGA provides representative data for research on work and health, designed as a cohort study with plans to rerun the survey 5 years after the first assessment. PMID:28673202

  7. Metagenomic analysis of bat guano samples revealed the presence of viruses potentially carried by insects, among others by Apis mellifera in Hungary.

    Science.gov (United States)

    Zana, Brigitta; Kemenesi, Gábor; Urbán, Péter; Földes, Fanni; Görföl, Tamás; Estók, Péter; Boldogh, Sándor; Kurucz, Kornélia; Jakab, Ferenc

    2018-03-01

    The predominance of dietary viruses in bat guano samples had been described recently, suggesting a new opportunity to survey the prevalence and to detect new viruses of arthropods or even plant-infecting viruses circulating locally in the ecosystem. Here we describe the diversity of viruses belonging to the order Picornavirales in Hungarian insectivorous bat guano samples. The metagenomic analysis conducted on our samples has revealed the significant predominance of aphid lethal paralysis virus (ALPV) and Big Sioux River virus (BSRV) in Hungary for the first time. Phylogenetic analysis was used to clarify the relationship to previously identified ALPV strains infecting honey bees, showing that our strain possesses a close genetic relationship with the strains that have already been described as pathogenic to honey bees. Furthermore, studies have previously confirmed the ability of these viruses to replicate in adult honey bees; however, no signs related to these viruses have been revealed yet. With the identification of two recently described possibly honey bee infecting viruses for the first time in Hungary, our results might have importance for the health conditions of Hungarian honey bee colonies in the future.

  8. Fear, Anger, and Risk Preference Reversals: An Experimental Study on a Chinese Sample.

    Science.gov (United States)

    She, Shengxiang; Eimontaite, Iveta; Zhang, Dangli; Sun, Yan

    2017-01-01

    Fear and anger are basic emotions of the same valence which differ in terms of their certainty and control dimensions according to the Appraisal Tendency Framework, a theory addressing the relationship between specific emotions, and judgments and choices. Past research based on the Appraisal Theory revealed contradictory results for risky choice decision-making. However, these conclusions were drawn from Western samples (e.g., North American). Considering potential cultural differences, the present study aims to investigate whether the Appraisal Tendency hypothesis yields the same results in a Chinese sample. Our first study explores how dispositional fear and anger influence risk preferences through a classic virtual "Asia Disease Problem" task and the second study investigates how induced fear and anger influence risk preferences through an incentive-compatible task. Consistent with previous research, our results reveal that induced fear and anger have differential effects on risky decisions: angry participants prefer the risk-seeking option, whereas fearful participants prefer a risk-averse option. However, we find no associations between dispositional fear (or anger) and risky decisions.

  9. Fear, Anger, and Risk Preference Reversals: An Experimental Study on a Chinese Sample

    Directory of Open Access Journals (Sweden)

    Shengxiang She

    2017-08-01

    Full Text Available Fear and anger are basic emotions of the same valence which differ in terms of their certainty and control dimensions according to the Appraisal Tendency Framework, a theory addressing the relationship between specific emotions, and judgments and choices. Past research based on the Appraisal Theory revealed contradictory results for risky choice decision-making. However, these conclusions were drawn from Western samples (e.g., North American. Considering potential cultural differences, the present study aims to investigate whether the Appraisal Tendency hypothesis yields the same results in a Chinese sample. Our first study explores how dispositional fear and anger influence risk preferences through a classic virtual “Asia Disease Problem” task and the second study investigates how induced fear and anger influence risk preferences through an incentive-compatible task. Consistent with previous research, our results reveal that induced fear and anger have differential effects on risky decisions: angry participants prefer the risk-seeking option, whereas fearful participants prefer a risk-averse option. However, we find no associations between dispositional fear (or anger and risky decisions.

  10. Nullspace Sampling with Holonomic Constraints Reveals Molecular Mechanisms of Protein Gαs.

    Directory of Open Access Journals (Sweden)

    Dimitar V Pachov

    2015-07-01

    Full Text Available Proteins perform their function or interact with partners by exchanging between conformational substates on a wide range of spatiotemporal scales. Structurally characterizing these exchanges is challenging, both experimentally and computationally. Large, diffusional motions are often on timescales that are difficult to access with molecular dynamics simulations, especially for large proteins and their complexes. The low frequency modes of normal mode analysis (NMA report on molecular fluctuations associated with biological activity. However, NMA is limited to a second order expansion about a minimum of the potential energy function, which limits opportunities to observe diffusional motions. By contrast, kino-geometric conformational sampling (KGS permits large perturbations while maintaining the exact geometry of explicit conformational constraints, such as hydrogen bonds. Here, we extend KGS and show that a conformational ensemble of the α subunit Gαs of heterotrimeric stimulatory protein Gs exhibits structural features implicated in its activation pathway. Activation of protein Gs by G protein-coupled receptors (GPCRs is associated with GDP release and large conformational changes of its α-helical domain. Our method reveals a coupled α-helical domain opening motion while, simultaneously, Gαs helix α5 samples an activated conformation. These motions are moderated in the activated state. The motion centers on a dynamic hub near the nucleotide-binding site of Gαs, and radiates to helix α4. We find that comparative NMA-based ensembles underestimate the amplitudes of the motion. Additionally, the ensembles fall short in predicting the accepted direction of the full activation pathway. Taken together, our findings suggest that nullspace sampling with explicit, holonomic constraints yields ensembles that illuminate molecular mechanisms involved in GDP release and protein Gs activation, and further establish conformational coupling between key

  11. The origin of water in the primitive Moon as revealed by the lunar highlands samples

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    Barnes, Jessica J.; Tartèse, Romain; Anand, Mahesh; McCubbin, Francis M.; Franchi, Ian A.; Starkey, Natalie A.; Russell, Sara S.

    2014-03-01

    The recent discoveries of hydrogen (H) bearing species on the lunar surface and in samples derived from the lunar interior have necessitated a paradigm shift in our understanding of the water inventory of the Moon, which was previously considered to be a ‘bone-dry’ planetary body. Most sample-based studies have focused on assessing the water contents of the younger mare basalts and pyroclastic glasses, which are partial-melting products of the lunar mantle. In contrast, little attention has been paid to the inventory and source(s) of water in the lunar highlands rocks which are some of the oldest and most pristine materials available for laboratory investigations, and that have the potential to reveal the original history of water in the Earth-Moon system. Here, we report in-situ measurements of hydroxyl (OH) content and H isotopic composition of the mineral apatite from four lunar highlands samples (two norites, a troctolite, and a granite clast) collected during the Apollo missions. Apart from troctolite in which the measured OH contents in apatite are close to our analytical detection limit and its H isotopic composition appears to be severely compromised by secondary processes, we have measured up to ˜2200 ppm OH in the granite clast with a weighted average δD of ˜ -105±130‰, and up to ˜3400 ppm OH in the two norites (77215 and 78235) with weighted average δD values of -281±49‰ and -27±98‰, respectively. The apatites in the granite clast and the norites are characterised by higher OH contents than have been reported so far for highlands samples, and have H isotopic compositions similar to those of terrestrial materials and some carbonaceous chondrites, providing one of the strongest pieces of evidence yet for a common origin for water in the Earth-Moon system. In addition, the presence of water, of terrestrial affinity, in some samples of the earliest-formed lunar crust suggests that either primordial terrestrial water survived the aftermath

  12. Sample size in qualitative interview studies

    DEFF Research Database (Denmark)

    Malterud, Kirsti; Siersma, Volkert Dirk; Guassora, Ann Dorrit Kristiane

    2016-01-01

    Sample sizes must be ascertained in qualitative studies like in quantitative studies but not by the same means. The prevailing concept for sample size in qualitative studies is “saturation.” Saturation is closely tied to a specific methodology, and the term is inconsistently applied. We propose...... the concept “information power” to guide adequate sample size for qualitative studies. Information power indicates that the more information the sample holds, relevant for the actual study, the lower amount of participants is needed. We suggest that the size of a sample with sufficient information power...... and during data collection of a qualitative study is discussed....

  13. Comparative Study of the Effect of Sample Pretreatment and Extraction on the Determination of Flavonoids from Lemon (Citrus limon)

    Science.gov (United States)

    Ledesma-Escobar, Carlos A.; Priego-Capote, Feliciano; Luque de Castro, María D.

    2016-01-01

    Background Flavonoids have shown to exert multiple beneficial effects on human health, being also appreciated by both food and pharmaceutical industries. Citrus fruits are a key source of flavonoids, thus promoting studies to obtain them. Characteristics of these studies are the discrepancies among sample pretreatments and among extraction methods, and also the scant number of comparative studies developed so far. Objective Evaluate the effect of both the sample pretreatment and the extraction method on the profile of flavonoids isolated from lemon. Results Extracts from fresh, lyophilized and air-dried samples obtained by shaking extraction (SE), ultrasound-assisted extraction (USAE), microwave-assisted extraction (MAE) and superheated liquid extraction (SHLE) were analyzed by LC–QTOF MS/MS, and 32 flavonoids were tentatively identified using MS/MS information. ANOVA applied to the data from fresh and dehydrated samples and from extraction by the different methods revealed that 26 and 32 flavonoids, respectively, were significant (p≤0.01). The pairwise comparison (Tukey HSD; p≤0.01) showed that lyophilized samples are more different from fresh samples than from air-dried samples; also, principal component analysis (PCA) showed a clear discrimination among sample pretreatment strategies and suggested that such differences are mainly created by the abundance of major flavonoids. On the other hand, pairwise comparison of extraction methods revealed that USAE and MAE provided quite similar extracts, being SHLE extracts different from the other two. In this case, PCA showed a clear discrimination among extraction methods, and their position in the scores plot suggests a lower abundance of flavonoids in the extracts from SHLE. In the two PCA the loadings plots revealed a trend to forming groups according to flavonoid aglycones. Conclusions The present study shows clear discrimination caused by both sample pretreatments and extraction methods. Under the studied

  14. Comparative Study of 11 Honey Samples Sold in Riyadh Saudi Arabia

    OpenAIRE

    Al Tufail, M. A. [محمد عبد الله الطفيل; Al Araidh, I. A. [ابراهيم عبد الله العريض

    2006-01-01

    11 honey various samples commercially available in Saudi Arabia, were subjected to chemical, toxicological and bacteriological tests. The samples were checked for As and CN, presence of pollens, and for bacteria contamination. The carbohydrate profile was analyzed with HPLC. Fe, P, Ca, K, and Mg were measured with colorimetry. Toxic metals, As, Pb, Sb, Tl, and Hg were determined with ICP-MS. The samples were investigated by GC-MS. The investigation revealed the presence of syringaldehyde, men...

  15. Stable isotope probing reveals the importance of Comamonas and Pseudomonadaceae in RDX degradation in samples from a Navy detonation site.

    Science.gov (United States)

    Jayamani, Indumathy; Cupples, Alison M

    2015-07-01

    This study investigated the microorganisms involved in hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) degradation from a detonation area at a Navy base. Using Illumina sequencing, microbial communities were compared between the initial sample, samples following RDX degradation, and controls not amended with RDX to determine which phylotypes increased in abundance following RDX degradation. The effect of glucose on these communities was also examined. In addition, stable isotope probing (SIP) using labeled ((13)C3, (15)N3-ring) RDX was performed. Illumina sequencing revealed that several phylotypes were more abundant following RDX degradation compared to the initial soil and the no-RDX controls. For the glucose-amended samples, this trend was strong for an unclassified Pseudomonadaceae phylotype and for Comamonas. Without glucose, Acinetobacter exhibited the greatest increase following RDX degradation compared to the initial soil and no-RDX controls. Rhodococcus, a known RDX degrader, also increased in abundance following RDX degradation. For the SIP study, unclassified Pseudomonadaceae was the most abundant phylotype in the heavy fractions in both the presence and absence of glucose. In the glucose-amended heavy fractions, the 16S ribosomal RNA (rRNA) genes of Comamonas and Anaeromxyobacter were also present. Without glucose, the heavy fractions also contained the 16S rRNA genes of Azohydromonas and Rhodococcus. However, all four phylotypes were present at a much lower level compared to unclassified Pseudomonadaceae. Overall, these data indicate that unclassified Pseudomonadaceae was primarily responsible for label uptake in both treatments. This study indicates, for the first time, the importance of Comamonas for RDX removal.

  16. Electron spin resonance of particulate soot samples from automobiles to help environmental studies

    International Nuclear Information System (INIS)

    Yamanaka, C.; Matsuda, T.; Ikeya, M.

    2005-01-01

    The application of electron spin resonance (ESR) was studied for diesel soot samples and suspended particulate matter (SPM) from automobile engines. Soot samples or diesel exhaust particles (DEP) were recovered at various points: in the exhaust pipe of a diesel engine, at the dust sampler of a highway tunnel (standard DEP), on the soundproofing wall alongside a heavy traffic road, and on the filters of a dust sampler for SPM. The diesel soot samples apparently showed two ESR spectra: one was a broad spectrum at g=2.1 with a line width of ca. 80-120mT and the other was a sharp signal of a carbon radical at g=2.003 with a line width of 0.4mT. Annealing experiments with a DEP sample at 250 deg. C revealed drastic enhancement of the sharp ESR signal, which suggested a thermal process of carbonization of remnant organics. An oximetric study by ESR showed an enhancement of the broad signal in the diesel soot sample as well as in the sharp ESR signal. Therefore, the main part of the broad ESR signal would be attributed to carbon radicals, which form a different configuration, probably closely interacting aggregates. Enhancement of the sharp ESR signal was not observed in the standard DEP sample under vacuum condition, which suggested less adsorption sites on the surface of DEP samples

  17. Longitudinal Study of Hepatitis A Infection by Saliva Sampling: The Kinetics of HAV Markers in Saliva Revealed the Application of Saliva Tests for Hepatitis A Study

    Science.gov (United States)

    Amado Leon, Luciane Almeida; de Almeida, Adilson José; de Paula, Vanessa Salete; Tourinho, Renata Santos; Villela, Daniel Antunes Maciel; Gaspar, Ana Maria Coimbra; Lewis-Ximenez, Lia Laura; Pinto, Marcelo Alves

    2015-01-01

    Despite the increasing numbers of studies investigating hepatitis A diagnostic through saliva, the frequency and the pattern of hepatitis A virus (HAV) markers in this fluid still remains unknown. To address this issue, we carried on a longitudinal study to examine the kinetics of HAV markers in saliva, in comparison with serum samples. The present study followed-up ten patients with acute hepatitis A infection during 180 days post diagnosis (dpd). Total anti-HAV was detected in paired serum and saliva samples until the end of the follow-up, showing a peak titer at 90th. However, total anti-HAV level was higher in serum than in saliva samples. This HAV marker showed a probability of 100% to be detected in both serum and saliva during 180 dpd. The IgM anti-HAV could be detected in saliva up to 150 dpd, showing the highest frequency at 30th, when it was detected in all individuals. During the first month of HAV infection, this acute HAV marker showed a detection probability of 100% in paired samples. The detection of IgM anti-HAV in saliva was not dependent on its level in serum, HAV-RNA detection and/or viral load, since no association was found between IgM anti-HAV positivity in saliva and any of these parameter (p>0.05). Most of the patients (80%) were found to contain HAV-RNA in saliva, mainly at early acute phase (30th day). However, it was possible to demonstrate the HAV RNA presence in paired samples for more than 90 days, even after seroconversion. No significant relationship was observed between salivary HAV-RNA positivity and serum viral load, demonstrating that serum viral load is not predictive of HAV-RNA detection in saliva. Similar viral load was seen in paired samples (on average 104 copies/mL). These data demonstrate that the best diagnostic coverage can be achieved by salivary anti-HAV antibodies and HAV-RNA tests during 30–90 dpd. The long detection and high probability of specific-HAV antibodies positivity in saliva samples make the assessment of

  18. Sample size of the reference sample in a case-augmented study.

    Science.gov (United States)

    Ghosh, Palash; Dewanji, Anup

    2017-05-01

    The case-augmented study, in which a case sample is augmented with a reference (random) sample from the source population with only covariates information known, is becoming popular in different areas of applied science such as pharmacovigilance, ecology, and econometrics. In general, the case sample is available from some source (for example, hospital database, case registry, etc.); however, the reference sample is required to be drawn from the corresponding source population. The required minimum size of the reference sample is an important issue in this regard. In this work, we address the minimum sample size calculation and discuss related issues. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  19. Denaturing gradient gel electrophoresis and barcoded pyrosequencing reveal unprecedented archaeal diversity in mangrove sediment and rhizosphere samples.

    Science.gov (United States)

    Pires, Ana C C; Cleary, Daniel F R; Almeida, Adelaide; Cunha, Angela; Dealtry, Simone; Mendonça-Hagler, Leda C S; Smalla, Kornelia; Gomes, Newton C M

    2012-08-01

    Mangroves are complex ecosystems that regulate nutrient and sediment fluxes to the open sea. The importance of bacteria and fungi in regulating nutrient cycles has led to an interest in their diversity and composition in mangroves. However, very few studies have assessed Archaea in mangroves, and virtually nothing is known about whether mangrove rhizospheres affect archaeal diversity and composition. Here, we studied the diversity and composition of Archaea in mangrove bulk sediment and the rhizospheres of two mangrove trees, Rhizophora mangle and Laguncularia racemosa, using denaturing gradient gel electrophoresis (DGGE) and pyrosequencing of archaeal 16S rRNA genes with a nested-amplification approach. DGGE profiles revealed significant structural differences between bulk sediment and rhizosphere samples, suggesting that roots of both mangrove species influence the sediment archaeal community. Nearly all of the detected sequences obtained with pyrosequencing were identified as Archaea, but most were unclassified at the level of phylum or below. Archaeal richness was, furthermore, the highest in the L. racemosa rhizosphere, intermediate in bulk sediment, and the lowest in the R. mangle rhizosphere. This study shows that rhizosphere microhabitats of R. mangle and L. racemosa, common plants in subtropical mangroves located in Rio de Janeiro, Brazil, hosted distinct archaeal assemblages.

  20. Study of adolescents exposed in utero. Methodological evaluation of the Nagasaki sample

    Energy Technology Data Exchange (ETDEWEB)

    Hrubec, Zdenek, Noble, K.B.; Burrow, G N

    1962-09-12

    Fetal tissues have been shown to be extremely sensitive to ionizing radiation, and therefore a group of children who were exposed in utero are of special interest. When these children entered adolescence, an intensive study was undertaken to determine whether differences not otherwise apparent would be revealed during the stress of this period of rapid growth. The purpose of this report is to describe the sample used to study these adolescent children who were exposed in utero and to provide reference information. The problems of using ex post facto methods as employed in this study have been discussed in detail elsewhere. In summary, the extent to which findings of a retrospective study may be generalized to a larger population can be determined only from a careful and extensive study of the characteristics of the sample and an evaluation of the procedures used in its selection. It is generally recognized that even an extensive methodologic exploration of this kind offers no conclusive proof that a sample is useful for a specific study. In the sample, some variables which may have a considerable effect on the medical data, such as socioeconomic status, have been taken into account only superficially. There is always the possibility that some important, completely unsuspected variables may produce spurious associations. However there is an almost infinite number of such factors which might conceivably affect the data. Vast research resources could be committed to a methodologic evaluation without fulfilling the basic purpose of the study. An approach must be devised which is judged methodologically adequate but which will not tax the research resource to the detriment of the basic objectives. It is hoped that this report will satisfy the requirements of this compromise. 30 references, 36 tables.

  1. Metabolomics reveals dose effects of low-dose chronic exposure to uranium in rats: identification of candidate biomarkers in urine samples.

    Science.gov (United States)

    Grison, Stéphane; Favé, Gaëlle; Maillot, Matthieu; Manens, Line; Delissen, Olivia; Blanchardon, Éric; Dublineau, Isabelle; Aigueperse, Jocelyne; Bohand, Sandra; Martin, Jean-Charles; Souidi, Maâmar

    2016-01-01

    Data are sparse about the potential health risks of chronic low-dose contamination of humans by uranium (natural or anthropogenic) in drinking water. Previous studies report some molecular imbalances but no clinical signs due to uranium intake. In a proof-of-principle study, we reported that metabolomics is an appropriate method for addressing this chronic low-dose exposure in a rat model (uranium dose: 40 mg L -1 ; duration: 9 months, n = 10). In the present study, our aim was to investigate the dose-effect pattern and identify additional potential biomarkers in urine samples. Compared to our previous protocol, we doubled the number of rats per group (n = 20), added additional sampling time points (3 and 6 months) and included several lower doses of natural uranium (doses used: 40, 1.5, 0.15 and 0.015 mg L -1 ). LC-MS metabolomics was performed on urine samples and statistical analyses were made with SIMCA-P+ and R packages. The data confirmed our previous results and showed that discrimination was both dose and time related. Uranium exposure was revealed in rats contaminated for 9 months at a dose as low as 0.15 mg L -1 . Eleven features, including the confidently identified N1-methylnicotinamide, N1-methyl-2-pyridone-5-carboxamide and 4-hydroxyphenylacetylglycine, discriminated control from contaminated rats with a specificity and a sensitivity ranging from 83 to 96 %, when combined into a composite score. These findings show promise for the elucidation of underlying radiotoxicologic mechanisms and the design of a diagnostic test to assess exposure in urine, in a dose range experimentally estimated to be above a threshold between 0.015 and 0.15 mg L -1 .

  2. Influence of population versus convenience sampling on sample characteristics in studies of cognitive aging.

    Science.gov (United States)

    Brodaty, Henry; Mothakunnel, Annu; de Vel-Palumbo, Melissa; Ames, David; Ellis, Kathryn A; Reppermund, Simone; Kochan, Nicole A; Savage, Greg; Trollor, Julian N; Crawford, John; Sachdev, Perminder S

    2014-01-01

    We examined whether differences in findings of studies examining mild cognitive impairment (MCI) were associated with recruitment methods by comparing sample characteristics in two contemporaneous Australian studies, using population-based and convenience sampling. The Sydney Memory and Aging Study invited participants randomly from the electoral roll in defined geographic areas in Sydney. The Australian Imaging, Biomarkers and Lifestyle Study of Ageing recruited cognitively normal (CN) individuals via media appeals and MCI participants via referrals from clinicians in Melbourne and Perth. Demographic and cognitive variables were harmonized, and similar diagnostic criteria were applied to both samples retrospectively. CN participants recruited via convenience sampling were younger, better educated, more likely to be married and have a family history of dementia, and performed better cognitively than those recruited via population-based sampling. MCI participants recruited via population-based sampling had better memory performance and were less likely to carry the apolipoprotein E ε4 allele than clinically referred participants but did not differ on other demographic variables. A convenience sample of normal controls is likely to be younger and better functioning and that of an MCI group likely to perform worse than a purportedly random sample. Sampling bias should be considered when interpreting findings. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Large Sample Neutron Activation Analysis of Heterogeneous Samples

    International Nuclear Information System (INIS)

    Stamatelatos, I.E.; Vasilopoulou, T.; Tzika, F.

    2018-01-01

    A Large Sample Neutron Activation Analysis (LSNAA) technique was developed for non-destructive analysis of heterogeneous bulk samples. The technique incorporated collimated scanning and combining experimental measurements and Monte Carlo simulations for the identification of inhomogeneities in large volume samples and the correction of their effect on the interpretation of gamma-spectrometry data. Corrections were applied for the effect of neutron self-shielding, gamma-ray attenuation, geometrical factor and heterogeneous activity distribution within the sample. A benchmark experiment was performed to investigate the effect of heterogeneity on the accuracy of LSNAA. Moreover, a ceramic vase was analyzed as a whole demonstrating the feasibility of the technique. The LSNAA results were compared against results obtained by INAA and a satisfactory agreement between the two methods was observed. This study showed that LSNAA is a technique capable to perform accurate non-destructive, multi-elemental compositional analysis of heterogeneous objects. It also revealed the great potential of the technique for the analysis of precious objects and artefacts that need to be preserved intact and cannot be damaged for sampling purposes. (author)

  4. Characterization of Fasciola samples by ITS of rDNA sequences revealed the existence of Fasciola hepatica and Fasciola gigantica in Yunnan Province, China.

    Science.gov (United States)

    Shu, Fan-Fan; Lv, Rui-Qing; Zhang, Yi-Fang; Duan, Gang; Wu, Ding-Yu; Li, Bi-Feng; Yang, Jian-Fa; Zou, Feng-Cai

    2012-08-01

    On mainland China, liver flukes of Fasciola spp. (Digenea: Fasciolidae) can cause serious acute and chronic morbidity in numerous species of mammals such as sheep, goats, cattle, and humans. The objective of the present study was to examine the taxonomic identity of Fasciola species in Yunnan province by sequences of the first and second internal transcribed spacers (ITS-1 and ITS-2) of nuclear ribosomal DNA (rDNA). The ITS rDNA was amplified from 10 samples representing Fasciola species in cattle from 2 geographical locations in Yunnan Province, by polymerase chain reaction (PCR), and the products were sequenced directly. The lengths of the ITS-1 and ITS-2 sequences were 422 and 361-362 base pairs, respectively, for all samples sequenced. Using ITS sequences, 2 Fasciola species were revealed, namely Fasciola hepatica and Fasciola gigantica. This is the first demonstration of F. gigantica in cattle in Yunnan Province, China using a molecular approach; our findings have implications for studying the population genetic characterization of the Chinese Fasciola species and for the prevention and control of Fasciola spp. in this province.

  5. Mechanistic Insights on Human Phosphoglucomutase Revealed by Transition Path Sampling and Molecular Dynamics Calculations.

    Science.gov (United States)

    Brás, Natércia F; Fernandes, Pedro A; Ramos, Maria J; Schwartz, Steven D

    2018-02-06

    Human α-phosphoglucomutase 1 (α-PGM) catalyzes the isomerization of glucose-1-phosphate into glucose-6-phosphate (G6P) through two sequential phosphoryl transfer steps with a glucose-1,6-bisphosphate (G16P) intermediate. Given that the release of G6P in the gluconeogenesis raises the glucose output levels, α-PGM represents a tempting pharmacological target for type 2 diabetes. Here, we provide the first theoretical study of the catalytic mechanism of human α-PGM. We performed transition-path sampling simulations to unveil the atomic details of the two catalytic chemical steps, which could be key for developing transition state (TS) analogue molecules with inhibitory properties. Our calculations revealed that both steps proceed through a concerted S N 2-like mechanism, with a loose metaphosphate-like TS. Even though experimental data suggests that the two steps are identical, we observed noticeable differences: 1) the transition state ensemble has a well-defined TS region and a late TS for the second step, and 2) larger coordinated protein motions are required to reach the TS of the second step. We have identified key residues (Arg23, Ser117, His118, Lys389), and the Mg 2+ ion that contribute in different ways to the reaction coordinate. Accelerated molecular dynamics simulations suggest that the G16P intermediate may reorient without leaving the enzymatic binding pocket, through significant conformational rearrangements of the G16P and of specific loop regions of the human α-PGM. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Treatability study sample exemption: update

    International Nuclear Information System (INIS)

    1997-01-01

    This document is a RCRA Information Brief intended to update the information in the 1991 Small-Scale Treatability Study Information Brief, and to address questions about the waste and treatability study sample exemptions that have arisen since References 3 and 5 were published

  7. Analysis of sequences from field samples reveals the presence of the recently described pepper vein yellows virus (genus Polerovirus) in six additional countries.

    Science.gov (United States)

    Knierim, Dennis; Tsai, Wen-Shi; Kenyon, Lawrence

    2013-06-01

    Polerovirus infection was detected by reverse transcription polymerase chain reaction (RT-PCR) in 29 pepper plants (Capsicum spp.) and one black nightshade plant (Solanum nigrum) sample collected from fields in India, Indonesia, Mali, Philippines, Thailand and Taiwan. At least two representative samples for each country were selected to generate a general polerovirus RT-PCR product of 1.4 kb length for sequencing. Sequence analysis of the partial genome sequences revealed the presence of pepper vein yellows virus (PeVYV) in all 13 samples. A 1990 Australian herbarium sample of pepper described by serological means as infected with capsicum yellows virus (CYV) was identified by sequence analysis of a partial CP sequence as probably infected with a potato leaf roll virus (PLRV) isolate.

  8. [Saarland Growth Study: sampling design].

    Science.gov (United States)

    Danker-Hopfe, H; Zabransky, S

    2000-01-01

    The use of reference data to evaluate the physical development of children and adolescents is part of the daily routine in the paediatric ambulance. The construction of such reference data is based on the collection of extensive reference data. There are different kinds of reference data: cross sectional references, which are based on data collected from a big representative cross-sectional sample of the population, longitudinal references, which are based on follow-up surveys of usually smaller samples of individuals from birth to maturity, and mixed longitudinal references, which are a combination of longitudinal and cross-sectional reference data. The advantages and disadvantages of the different methods of data collection and the resulting reference data are discussed. The Saarland Growth Study was conducted for several reasons: growth processes are subject to secular changes, there are no specific reference data for children and adolescents from this part of the country and the growth charts in use in the paediatric praxis are possibly not appropriate any more. Therefore, the Saarland Growth Study served two purposes a) to create actual regional reference data and b) to create a database for future studies on secular trends in growth processes of children and adolescents from Saarland. The present contribution focusses on general remarks on the sampling design of (cross-sectional) growth surveys and its inferences for the design of the present study.

  9. Sampling pig farms at the abattoir in a cross-sectional study - Evaluation of a sampling method.

    Science.gov (United States)

    Birkegård, Anna Camilla; Halasa, Tariq; Toft, Nils

    2017-09-15

    A cross-sectional study design is relatively inexpensive, fast and easy to conduct when compared to other study designs. Careful planning is essential to obtaining a representative sample of the population, and the recommended approach is to use simple random sampling from an exhaustive list of units in the target population. This approach is rarely feasible in practice, and other sampling procedures must often be adopted. For example, when slaughter pigs are the target population, sampling the pigs on the slaughter line may be an alternative to on-site sampling at a list of farms. However, it is difficult to sample a large number of farms from an exact predefined list, due to the logistics and workflow of an abattoir. Therefore, it is necessary to have a systematic sampling procedure and to evaluate the obtained sample with respect to the study objective. We propose a method for 1) planning, 2) conducting, and 3) evaluating the representativeness and reproducibility of a cross-sectional study when simple random sampling is not possible. We used an example of a cross-sectional study with the aim of quantifying the association of antimicrobial resistance and antimicrobial consumption in Danish slaughter pigs. It was not possible to visit farms within the designated timeframe. Therefore, it was decided to use convenience sampling at the abattoir. Our approach was carried out in three steps: 1) planning: using data from meat inspection to plan at which abattoirs and how many farms to sample; 2) conducting: sampling was carried out at five abattoirs; 3) evaluation: representativeness was evaluated by comparing sampled and non-sampled farms, and the reproducibility of the study was assessed through simulated sampling based on meat inspection data from the period where the actual data collection was carried out. In the cross-sectional study samples were taken from 681 Danish pig farms, during five weeks from February to March 2015. The evaluation showed that the sampling

  10. Application of Fourier analysis to the study of roughness profiles of eroded samples

    International Nuclear Information System (INIS)

    Bethencourt, M.; Botana, F.J.; Calvino, J.J.; Marcos, M.; Rodriguez-Chacon, M.A.

    1998-01-01

    Fourier transforms are applied to analyse surface roughness profiles recorded on samples coming from erosion-corrosion essays. The information retrieved using this method clearly complements that revealed by the more classical roughness amplitude parameters. The analysis procedure here proposed can be applied not only to characterise the surface of corroded samples but, in general, to evaluate the quality of any surface after application of finishing treatments. (Author) 7 refs

  11. Biological Sampling Variability Study

    Energy Technology Data Exchange (ETDEWEB)

    Amidan, Brett G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hutchison, Janine R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-11-08

    There are many sources of variability that exist in the sample collection and analysis process. This paper addresses many, but not all, sources of variability. The main focus of this paper was to better understand and estimate variability due to differences between samplers. Variability between days was also studied, as well as random variability within each sampler. Experiments were performed using multiple surface materials (ceramic and stainless steel), multiple contaminant concentrations (10 spores and 100 spores), and with and without the presence of interfering material. All testing was done with sponge sticks using 10-inch by 10-inch coupons. Bacillus atrophaeus was used as the BA surrogate. Spores were deposited using wet deposition. Grime was coated on the coupons which were planned to include the interfering material (Section 3.3). Samples were prepared and analyzed at PNNL using CDC protocol (Section 3.4) and then cultured and counted. Five samplers were trained so that samples were taken using the same protocol. Each sampler randomly sampled eight coupons each day, four coupons with 10 spores deposited and four coupons with 100 spores deposited. Each day consisted of one material being tested. The clean samples (no interfering materials) were run first, followed by the dirty samples (coated with interfering material). There was a significant difference in recovery efficiency between the coupons with 10 spores deposited (mean of 48.9%) and those with 100 spores deposited (mean of 59.8%). There was no general significant difference between the clean and dirty (containing interfering material) coupons or between the two surface materials; however, there was a significant interaction between concentration amount and presence of interfering material. The recovery efficiency was close to the same for coupons with 10 spores deposited, but for the coupons with 100 spores deposited, the recovery efficiency for the dirty samples was significantly larger (65

  12. A novel method for RNA extraction from FFPE samples reveals significant differences in biomarker expression between orthotopic and subcutaneous pancreatic cancer patient-derived xenografts.

    Science.gov (United States)

    Hoover, Malachia; Adamian, Yvess; Brown, Mark; Maawy, Ali; Chang, Alexander; Lee, Jacqueline; Gharibi, Armen; Katz, Matthew H; Fleming, Jason; Hoffman, Robert M; Bouvet, Michael; Doebler, Robert; Kelber, Jonathan A

    2017-01-24

    Next-generation sequencing (NGS) can identify and validate new biomarkers of cancer onset, progression and therapy resistance. Substantial archives of formalin-fixed, paraffin-embedded (FFPE) cancer samples from patients represent a rich resource for linking molecular signatures to clinical data. However, performing NGS on FFPE samples is limited by poor RNA purification methods. To address this hurdle, we developed an improved methodology for extracting high-quality RNA from FFPE samples. By briefly integrating a newly-designed micro-homogenizing (mH) tool with commercially available FFPE RNA extraction protocols, RNA recovery is increased by approximately 3-fold while maintaining standard A260/A280 ratios and RNA quality index (RQI) values. Furthermore, we demonstrate that the mH-purified FFPE RNAs are longer and of higher integrity. Previous studies have suggested that pancreatic ductal adenocarcinoma (PDAC) gene expression signatures vary significantly under in vitro versus in vivo and in vivo subcutaneous versus orthotopic conditions. By using our improved mH-based method, we were able to preserve established expression patterns of KRas-dependency genes within these three unique microenvironments. Finally, expression analysis of novel biomarkers in KRas mutant PDAC samples revealed that PEAK1 decreases and MST1R increases by over 100-fold in orthotopic versus subcutaneous microenvironments. Interestingly, however, only PEAK1 levels remain elevated in orthotopically grown KRas wild-type PDAC cells. These results demonstrate the critical nature of the orthotopic tumor microenvironment when evaluating the clinical relevance of new biomarkers in cells or patient-derived samples. Furthermore, this new mH-based FFPE RNA extraction method has the potential to enhance and expand future FFPE-RNA-NGS cancer biomarker studies.

  13. Scanning Ion Conductance Microscopy for Studying Biological Samples

    Directory of Open Access Journals (Sweden)

    Irmgard D. Dietzel

    2012-11-01

    Full Text Available Scanning ion conductance microscopy (SICM is a scanning probe technique that utilizes the increase in access resistance that occurs if an electrolyte filled glass micro-pipette is approached towards a poorly conducting surface. Since an increase in resistance can be monitored before the physical contact between scanning probe tip and sample, this technique is particularly useful to investigate the topography of delicate samples such as living cells. SICM has shown its potential in various applications such as high resolution and long-time imaging of living cells or the determination of local changes in cellular volume. Furthermore, SICM has been combined with various techniques such as fluorescence microscopy or patch clamping to reveal localized information about proteins or protein functions. This review details the various advantages and pitfalls of SICM and provides an overview of the recent developments and applications of SICM in biological imaging. Furthermore, we show that in principle, a combination of SICM and ion selective micro-electrodes enables one to monitor the local ion activity surrounding a living cell.

  14. Archaeological and taxonomic significance of ancient wood samples ...

    African Journals Online (AJOL)

    Ancient wood samples from an archaeological excavation, Test Pit II, in Ahanve, near Badagry were analysed to ascertain their identity. Anatomical study of the wood samples revealed oval-circular xylem pores, diffuse apotracheal axial parenchyma, procumbent and homogeneous ray and non-septate fibres, all consistent ...

  15. Predator-guided sampling reveals biotic structure in the bathypelagic.

    Science.gov (United States)

    Benoit-Bird, Kelly J; Southall, Brandon L; Moline, Mark A

    2016-02-24

    We targeted a habitat used differentially by deep-diving, air-breathing predators to empirically sample their prey's distributions off southern California. Fine-scale measurements of the spatial variability of potential prey animals from the surface to 1,200 m were obtained using conventional fisheries echosounders aboard a surface ship and uniquely integrated into a deep-diving autonomous vehicle. Significant spatial variability in the size, composition, total biomass, and spatial organization of biota was evident over all spatial scales examined and was consistent with the general distribution patterns of foraging Cuvier's beaked whales (Ziphius cavirostris) observed in separate studies. Striking differences found in prey characteristics between regions at depth, however, did not reflect differences observed in surface layers. These differences in deep pelagic structure horizontally and relative to surface structure, absent clear physical differences, change our long-held views of this habitat as uniform. The revelation that animals deep in the water column are so spatially heterogeneous at scales from 10 m to 50 km critically affects our understanding of the processes driving predator-prey interactions, energy transfer, biogeochemical cycling, and other ecological processes in the deep sea, and the connections between the productive surface mixed layer and the deep-water column. © 2016 The Author(s).

  16. Individual differences in fluid intelligence predicts inattentional blindness in a sample of older adults: a preliminary study.

    Science.gov (United States)

    O'Shea, Deirdre M; Fieo, Robert A

    2015-07-01

    Previous research has shown that aging increases susceptibility to inattentional blindness (Graham and Burke, Psychol Aging 26:162, 2011) as well as individual differences in cognitive ability related to working memory and executive functions in separate studies. Therefore, the present study was conducted in an attempt to bridge a gap that involved investigating 'age-sensitive' cognitive abilities that may predict inattentional blindness in a sample of older adults. We investigated whether individual differences in general fluid intelligence and speed of processing would predict inattentional blindness in our sample of older adults. Thirty-six healthy older adults took part in the study. Using the inattentional blindness paradigm developed by Most et al. (Psychol Rev 112:217, 2005), we investigated whether rates of inattentional blindness could be predicted by participant's performance on the Raven's Advanced Progressive Matrices and a choice-reaction time task. A Mann-Whitney U test revealed that a higher score on the Raven's Advanced Progressive Matrices was significantly associated with lower incidences of inattentional blindness. However, a t test revealed that choice-reaction times were not significantly associated with inattentional blindness. Preliminary results from the present study suggest that individual differences in general fluid intelligence are predictive of inattentional blindness in older adults but not speed of processing. Moreover, our findings are consistent with previous studies that have suggested executive attention control may be the source of these individual differences. These findings also highlight the association between attention and general fluid intelligence and how it may impact environmental awareness. Future research would benefit from repeating these analyses in a larger sample and also including a younger comparison group.

  17. Revealed social preference for potable groundwater: An Eastern Iowa case study

    Science.gov (United States)

    Raunikar, R. P.; Bernknopf, R. L.; Forney, W.; Mishra, S.

    2011-12-01

    The spatially explicit land use and land cover information provided by Landsat moderate-resolution land imagery (MRLI) is needed to more efficiently balance the production of goods and services over landscapes. For example, economic trade-offs are needed to provide both clean groundwater resources and other non-environmental goods and services produced by activities that affect the vadose zone and thus contribute to contamination of groundwater. These trade-off choices are made by numerous economic agents and are constrained by many social institutions including governmental regulations at many levels, contractual obligations and traditions. In effect, on a social level, society acts as if it values groundwater by foregoing other goods to protect these resources. The result of the protection afforded to groundwater resources is observable by measuring contamination in well samples. This observed level of groundwater contamination risk is the revealed preference of society as a whole for clean groundwater. We observed the risk of groundwater contamination in a sampling of well data from our study area (35 counties of Eastern Iowa.) We used a proportional hazard model to quantify the nitrate contamination survival implied by the panel of 19,873 well data, where remaining below a 10 mg/ml maximum contamination level (MCL) is defined as survival. We tested the data for evidence that the levels of protection provided to these resources is correlated with aquifer and vadose zone characteristics and geographic location and whether it changed over time and with economic and other conditions. We demonstrate the use of a nitrate conditioned hazard function for projecting the survival of wells based on nitrate exposure information over the 1940 to 2010 time period. We discuss results of simulations of the survival process that demonstrate the economic significance of this approach. We find that aquifer survival has been significantly improving over time. The principle of

  18. Systematic versus random sampling in stereological studies.

    Science.gov (United States)

    West, Mark J

    2012-12-01

    The sampling that takes place at all levels of an experimental design must be random if the estimate is to be unbiased in a statistical sense. There are two fundamental ways by which one can make a random sample of the sections and positions to be probed on the sections. Using a card-sampling analogy, one can pick any card at all out of a deck of cards. This is referred to as independent random sampling because the sampling of any one card is made without reference to the position of the other cards. The other approach to obtaining a random sample would be to pick a card within a set number of cards and others at equal intervals within the deck. Systematic sampling along one axis of many biological structures is more efficient than random sampling, because most biological structures are not randomly organized. This article discusses the merits of systematic versus random sampling in stereological studies.

  19. Sample size calculations for case-control studies

    Science.gov (United States)

    This R package can be used to calculate the required samples size for unconditional multivariate analyses of unmatched case-control studies. The sample sizes are for a scalar exposure effect, such as binary, ordinal or continuous exposures. The sample sizes can also be computed for scalar interaction effects. The analyses account for the effects of potential confounder variables that are also included in the multivariate logistic model.

  20. Human bloodstains on bone artefacts: an SEM intra- and inter-sample comparative study using ratite bird tibiotarsus.

    Science.gov (United States)

    Hortolà, Policarp

    2016-11-01

    Apart from their forensic significance in crime investigation, human bloodstains have an anthropological interest due to their occurrence on certain traditional weapons and ritual objects. Previously, a guiding study of erythrocytes in experimental samples including domestic sheep (Ovis aries) tibia was carried out using a scanning electron microscope (SEM). Here, a comparative SEM study to reveal the potential differences in bloodstain surface morphology as a function of intra-sample (smear region) and inter-sample (individual smear, smearing mechanism, bone origin) parameters is reported. A fragment of emu (Dromaius novaehollandiae) tibiotarsus was smeared with an adult man's peripheral blood. After air-drying and storing indoors, the boundary and neighbouring inner areas of the three individual bloodstains obtained were examined via secondary electrons in a variable-pressure SEM working in low-vacuum mode. As a whole, desiccation microcracks were present, the limits between the smear and the substrate appeared poorly defined, and no erythrocyte negative replicas were observed in the examined areas. In addition, a putative fibrin network, more or less embedded in the dried plasma matrix, was observed in the smears' boundary. Regarding the smear region in sliding smears, the periphery and boundary revealed to be different, while the head and tail were similar. Considering individual sliding smears, they had similar characteristics. Relating to the smear region as a function of the smearing mechanism, the periphery was different whether sliding or touching, while the boundary was similar in sliding and touching smears. Concerning the smear region as a function of the bone origin, the periphery revealed to be similar in both ratite and mammalian bone, while the boundary did different in ratite and mammalian bone. The results of this study show that SEM examination can be used fruitfully to detect bloodstains on ratite bone. Combined with previous SEM results in

  1. Shame, personality, and social anxiety symptoms in Chinese and American nonclinical samples: a cross-cultural study.

    Science.gov (United States)

    Zhong, Jie; Wang, Aimin; Qian, Mingyi; Zhang, Lili; Gao, Jun; Yang, Jianxiang; Li, Bo; Chen, Ping

    2008-01-01

    Shame has been observed to play an important role in social anxiety in China [Xu, 1982]. Shame and personality factors, such as neuroticism and introversion-extraversion, are also related to social anxiety symptoms in Chinese college students [Li et al., 2003]. The aim of this study was to explore cross-cultural differences of the effects of shame and personality on social anxiety using the Experience Scale of Shame, the Eysenck Personality Questionnaire-Revised Short Scale and Social Anxiety Inventory. Data were collected from both a Chinese sample (n=211, 66 males and 145 females, average ages 20.12+/-1.56 years) and an American sample (n=211, 66 males and 145 females, average ages 20.22+/-1.90 years) of college students. The structural equation modeling (SEM) was performed separately for the Chinese and American samples. The SEM results reveal a shame-mediating model, which is adaptive and only in the Chinese sample. This suggests that shame is a mediator between the Chinese personality and social anxiety. The shame factor did not play the same role in the American sample. This empirical study supports the hypothesis that shame has a more important effect on social anxiety in the Chinese culture compared to its effect on Americans. (c) 2007 Wiley-Liss, Inc.

  2. Mars Sample Return Architecture Assessment Study

    Science.gov (United States)

    Centuori, S.; Hermosín, P.; Martín, J.; De Zaiacomo, G.; Colin, S.; Godfrey, A.; Myles, J.; Johnson, H.; Sachdev, T.; Ahmed, R.

    2018-04-01

    Current paper presents the results of ESA funded activity "Mars Sample Return Architecture Assessment Study" carried-out by DEIMOS Space, Lockheed Martin UK Ampthill, and MDA Corporation, where more than 500 mission design options have been studied.

  3. Extreme conditions magnetostriction study of the Shastry-Sutherland sample SCBO

    Science.gov (United States)

    Grockowiak, Audrey; Wehinger, BjöRn; Coniglio, William; Ruegg, Chistian; Tozer, Stanley; National High Magnetic Field Laboratory Team; Paul Scherrer Institute Collaboration

    The Shasty-Sutherland model, which consists of a set of spin 1/2 dimers on a 2D square lattice, is simple and soluble but captures a central theme of condensed matter physics by sitting precariously on the quantum edge between isolated, gapped excitations and collective, ordered ground states. This model is realized in SrCu2(BO3)2. Recent x-ray diffraction data revealed a direct correlation of the lattice with magnetic susceptibility measurements at low temperatures. The variation of the lattice parameters with temperature is thus directly linked to the spin response of the system. Indeed, scattering intensities from the spin waves, measured by inelastic neutron scattering experiments, decay accordingly. The magnetic correlations can thus be monitored by the lattice parameters and are thus sensitive to magnetostriction. Ambient pressure magnetostriction up to 100.7 T show clear signatures related to the magnetization plateaus at 30, 40 and 80T. Together with total energy calculations these studies revealed a strong magneto elastic coupling driven by the super exchange angle CuOCu. Applying hydrostatic external pressure results in continuous and discontinuous quantum phase transitions. Zero field high pressure neutron spectroscopy measurements have revealed so far three phases : spin dimer from 0 to 2GPa, antiferromagnetic from 4 to 6 GPa, and a 4-spin plaquette singlet state was recently identified in the 2 to 4GPa region. We report here on high pressure (up to 2GPa), high magnetic field (up to 65T) and 3He temperature magnetostriction experiments, using FBGs. Fiber Bragg Grating (FBG) Dilatometry permits to measure the magnetostriction of a sample in function of the response of an optical fiber to applied strain. This work was performed at the NHMFL, supported by the NSF Cooperative Agreement No. DMR-1157490 and the State of Florida, and the DOE NNSA DE-NA0001979 Grant.

  4. Sample size calculation in metabolic phenotyping studies.

    Science.gov (United States)

    Billoir, Elise; Navratil, Vincent; Blaise, Benjamin J

    2015-09-01

    The number of samples needed to identify significant effects is a key question in biomedical studies, with consequences on experimental designs, costs and potential discoveries. In metabolic phenotyping studies, sample size determination remains a complex step. This is due particularly to the multiple hypothesis-testing framework and the top-down hypothesis-free approach, with no a priori known metabolic target. Until now, there was no standard procedure available to address this purpose. In this review, we discuss sample size estimation procedures for metabolic phenotyping studies. We release an automated implementation of the Data-driven Sample size Determination (DSD) algorithm for MATLAB and GNU Octave. Original research concerning DSD was published elsewhere. DSD allows the determination of an optimized sample size in metabolic phenotyping studies. The procedure uses analytical data only from a small pilot cohort to generate an expanded data set. The statistical recoupling of variables procedure is used to identify metabolic variables, and their intensity distributions are estimated by Kernel smoothing or log-normal density fitting. Statistically significant metabolic variations are evaluated using the Benjamini-Yekutieli correction and processed for data sets of various sizes. Optimal sample size determination is achieved in a context of biomarker discovery (at least one statistically significant variation) or metabolic exploration (a maximum of statistically significant variations). DSD toolbox is encoded in MATLAB R2008A (Mathworks, Natick, MA) for Kernel and log-normal estimates, and in GNU Octave for log-normal estimates (Kernel density estimates are not robust enough in GNU octave). It is available at http://www.prabi.fr/redmine/projects/dsd/repository, with a tutorial at http://www.prabi.fr/redmine/projects/dsd/wiki. © The Author 2015. Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  5. Neuromuscular dose-response studies: determining sample size.

    Science.gov (United States)

    Kopman, A F; Lien, C A; Naguib, M

    2011-02-01

    Investigators planning dose-response studies of neuromuscular blockers have rarely used a priori power analysis to determine the minimal sample size their protocols require. Institutional Review Boards and peer-reviewed journals now generally ask for this information. This study outlines a proposed method for meeting these requirements. The slopes of the dose-response relationships of eight neuromuscular blocking agents were determined using regression analysis. These values were substituted for γ in the Hill equation. When this is done, the coefficient of variation (COV) around the mean value of the ED₅₀ for each drug is easily calculated. Using these values, we performed an a priori one-sample two-tailed t-test of the means to determine the required sample size when the allowable error in the ED₅₀ was varied from ±10-20%. The COV averaged 22% (range 15-27%). We used a COV value of 25% in determining the sample size. If the allowable error in finding the mean ED₅₀ is ±15%, a sample size of 24 is needed to achieve a power of 80%. Increasing 'accuracy' beyond this point requires increasing greater sample sizes (e.g. an 'n' of 37 for a ±12% error). On the basis of the results of this retrospective analysis, a total sample size of not less than 24 subjects should be adequate for determining a neuromuscular blocking drug's clinical potency with a reasonable degree of assurance.

  6. Study of phosphors determination in biological samples

    International Nuclear Information System (INIS)

    Oliveira, Rosangela Magda de.

    1994-01-01

    In this paper, phosphors determination by neutron activation analysis in milk and bone samples was studied employing both instrumental and radiochemical separation methods. The analysis with radiochemistry separation consisted of the simultaneous irradiation of the samples and standards during 30 minutes, dissolution of the samples, hold back carrier, addition precipitation of phosphorus with ammonium phosphomolibdate (A.M.P.) and phosphorus-32 by counting by using Geiger-Mueller detector. The instrumental analysis consisted of the simultaneous irradiation of the samples and standards during 30 minutes, transfer of the samples into a counting planchet and measurement of the beta radiation emitted by phosphorus-32, after a suitable decay period. After the phosphorus analysis methods were established they were applied to both commercial milk and animal bone samples, and data obtained in the instrumental and radiochemical separation methods for each sample, were compared between themselves. In this work, it became possible to obtain analysis methods for phosphorus that can be applied independently of the sample quantity available, and the phosphorus content in the samples or interference that can be present in them. (author). 51 refs., 7 figs., 4 tabs

  7. Sampling study in milk storage tanks by INAA

    International Nuclear Information System (INIS)

    Santos, L.G.C.; Nadai Fernandes de, E.A.; Bacchi, M.A.; Tagliaferro, F.S.

    2008-01-01

    This study investigated the representativeness of samples for assessing chemical elements in milk bulk tanks. Milk samples were collected from a closed tank in a dairy plant and from an open top tank in a dairy farm. Samples were analyzed for chemical elements by instrumental neutron activation analysis (INAA). For both experiments, Br, Ca, Cs, K, Na, Rb and Zn did not present significant differences between samples thereby indicating the appropriateness of the sampling procedure adopted to evaluate the analytes of interest. (author)

  8. Influence of Sampling Practices on the Appearance of DNA Image Histograms of Prostate Cells in FNAB Samples

    Directory of Open Access Journals (Sweden)

    Abdelbaset Buhmeida

    1999-01-01

    Full Text Available Twenty‐one fine needle aspiration biopsies (FNAB of the prostate, diagnostically classified as definitely malignant, were studied. The Papanicolaou or H&E stained samples were destained and then stained for DNA with the Feulgen reaction. DNA cytometry was applied after different sampling rules. The histograms varied according to the sampling rule applied. Because free cells between cell groups were easier to measure than cells in the cell groups, two sampling rules were tested in all samples: (i cells in the cell groups were measured, and (ii free cells between cell groups were measured. Abnormal histograms were more common after the sampling rule based on free cells, suggesting that abnormal patterns are best revealed through the free cells in these samples. The conclusions were independent of the applied histogram interpretation method.

  9. Feasibility of self-sampled dried blood spot and saliva samples sent by mail in a population-based study.

    Science.gov (United States)

    Sakhi, Amrit Kaur; Bastani, Nasser Ezzatkhah; Ellingjord-Dale, Merete; Gundersen, Thomas Erik; Blomhoff, Rune; Ursin, Giske

    2015-04-11

    In large epidemiological studies it is often challenging to obtain biological samples. Self-sampling by study participants using dried blood spots (DBS) technique has been suggested to overcome this challenge. DBS is a type of biosampling where blood samples are obtained by a finger-prick lancet, blotted and dried on filter paper. However, the feasibility and efficacy of collecting DBS samples from study participants in large-scale epidemiological studies is not known. The aim of the present study was to test the feasibility and response rate of collecting self-sampled DBS and saliva samples in a population-based study of women above 50 years of age. We determined response proportions, number of phone calls to the study center with questions about sampling, and quality of the DBS. We recruited women through a study conducted within the Norwegian Breast Cancer Screening Program. Invitations, instructions and materials were sent to 4,597 women. The data collection took place over a 3 month period in the spring of 2009. Response proportions for the collection of DBS and saliva samples were 71.0% (3,263) and 70.9% (3,258), respectively. We received 312 phone calls (7% of the 4,597 women) with questions regarding sampling. Of the 3,263 individuals that returned DBS cards, 3,038 (93.1%) had been packaged and shipped according to instructions. A total of 3,032 DBS samples were sufficient for at least one biomarker analysis (i.e. 92.9% of DBS samples received by the laboratory). 2,418 (74.1%) of the DBS cards received by the laboratory were filled with blood according to the instructions (i.e. 10 completely filled spots with up to 7 punches per spot for up to 70 separate analyses). To assess the quality of the samples, we selected and measured two biomarkers (carotenoids and vitamin D). The biomarker levels were consistent with previous reports. Collecting self-sampled DBS and saliva samples through the postal services provides a low cost, effective and feasible

  10. Amygdala subnuclei connectivity in response to violence reveals unique influences of individual differences in psychopathic traits in a nonforensic sample.

    Science.gov (United States)

    Yoder, Keith J; Porges, Eric C; Decety, Jean

    2015-04-01

    Atypical amygdala function and connectivity have reliably been associated with psychopathy. However, the amygdala is not a unitary structure. To examine how psychopathic traits in a nonforensic sample are linked to amygdala response to violence, this study used probabilistic tractography to classify amygdala subnuclei based on anatomical projections to and from amygdala subnuclei in a group of 43 male participants. The segmentation identified the basolateral complex (BLA; lateral, basal, and accessory basal subnuclei) and the central subnucleus (CE), which were used as seeds in a functional connectivity analysis to identify differences in neuronal coupling specific to observed violence. While a full amygdala seed showed significant connectivity only to right middle occipital gyrus, subnuclei seeds revealed unique connectivity patterns. BLA showed enhanced coupling with anterior cingulate and prefrontal regions, while CE showed increased connectivity with the brainstem, but reduced connectivity with superior parietal and precentral gyrus. Further, psychopathic personality factors were related to specific patterns of connectivity. Fearless Dominance scores on the psychopathic personality inventory predicted increased coupling between the BLA seed and sensory integration cortices, and increased connectivity between the CE seed and posterior insula. Conversely, Self-Centered Impulsivity scores were negatively correlated with coupling between BLA and ventrolateral prefrontal cortex, and Coldheartedness scores predicted increased functional connectivity between BLA and dorsal anterior cingulate cortex. Taken together, these findings demonstrate how subnuclei segmentations reveal important functional connectivity differences that are otherwise inaccessible. Such an approach yields a better understanding of amygdala dysfunction in psychopathy. © 2014 Wiley Periodicals, Inc.

  11. On peculiarities of distribution of some elements in vegetation samples

    International Nuclear Information System (INIS)

    Bakiev, S.A.; Rakhmanov, J.; Khakimov, Z.M.; Turayev, S.

    2005-01-01

    This work is devoted to the neutron-activation analysis of medicines of vegetation origin and some herbs, vegetables, fruits and cereals, which are used in oriental medicine, in order to reveal peculiarities of distribution of studied elements in them and possible relations between this distribution and parameters of oriental medicine. The sampling involving 85 species and their preparation for analysis, as well as complex of necessary methodological studies were performed and the method of sample analysis for 14 macro- and microelements (Na, Al, Cl, K, Sc, Mn, Fe, Co, Cu, Zn, Br, J, La, Au) was developed. The studies carried out have enabled one to obtain data on concentrations of these elements and to reveal peculiarities of their distribution in the samples under interest. It was revealed herbs, fruits and cereals with pronounced higher concentrations (with respect to the mean values) of one or another element, which are perhaps concentrators of those elements, as well as samples with lower concentrations of elements (see table). It is indicative that in all herbs only enhanced concentrations of elements are observed, but in fruits and cereals-only lowered concentrations of elements. These results can be of interest for geochemical ecology, dietology, therapy, as well as for activities on correction of elemental content of ecosystems, including soils, and alive organisms It is suggested to continue studies with extension of range of object types and analysed elements. Mathematical analysis of the obtained results was performed with comparison of concentrations of a number of elements in the different objects with classifying parameters ('cold-hot' and 'dry-wet') of these objects according to oriental medicine. In the current stage of studies no relation between these parameters and concentrations has been found. It does not mean that there are not such relations at all, they may be revealed with extension and development of our' studies.

  12. Lunar sample studies

    International Nuclear Information System (INIS)

    1977-01-01

    Lunar samples discussed and the nature of their analyses are: (1) an Apollo 15 breccia which is thoroughly analyzed as to the nature of the mature regolith from which it derived and the time and nature of the lithification process, (2) two Apollo 11 and one Apollo 12 basalts analyzed in terms of chemistry, Cross-Iddings-Pirsson-Washington norms, mineralogy, and petrography, (3) eight Apollo 17 mare basalts, also analyzed in terms of chemistry, Cross-Iddings-Pirsson-Washington norms, mineralogy, and petrography. The first seven are shown to be chemically similar although of two main textural groups; the eighth is seen to be distinct in both chemistry and mineralogy, (4) a troctolitic clast from a Fra Mauro breccia, analyzed and contrasted with other high-temperature lunar mineral assemblages. Two basaltic clasts from the same breccia are shown to have affinities with rock 14053, and (5) the uranium-thorium-lead systematics of three Apollo 16 samples are determined; serious terrestrial-lead contamination of the first two samples is attributed to bandsaw cutting in the lunar curatorial facility

  13. Direct analysis by time-of-flight secondary ion mass spectrometry reveals action of bacterial laccase-mediator systems on both hardwood and softwood samples.

    Science.gov (United States)

    Goacher, Robyn E; Braham, Erick J; Michienzi, Courtney L; Flick, Robert M; Yakunin, Alexander F; Master, Emma R

    2017-12-29

    The modification and degradation of lignin play a vital role in carbon cycling as well as production of biofuels and bioproducts. The possibility of using bacterial laccases for the oxidation of lignin offers a route to utilize existing industrial protein expression techniques. However, bacterial laccases are most frequently studied on small model compounds that do not capture the complexity of lignocellulosic materials. This work studied the action of laccases from Bacillus subtilis and Salmonella typhimurium (EC 1.10.3.2) on ground wood samples from yellow birch (Betula alleghaniensis) and red spruce (Picea rubens). The ability of bacterial laccases to modify wood can be facilitated by small molecule mediators. Herein, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), gallic acid and sinapic acid mediators were tested. Direct analysis of the wood samples was achieved by time-of-flight secondary ion mass spectrometry (ToF-SIMS), a surface sensitive mass spectrometry technique that has characteristic peaks for H, G and S lignin. The action of the bacterial laccases on both wood samples was demonstrated and revealed a strong mediator influence. The ABTS mediator led to delignification, evident in an overall increase of polysaccharide peaks in the residual solid, along with equal loss of G and S-lignin peaks. The gallic acid mediator demonstrated minimal laccase activity. Meanwhile, the sinapic acid mediator altered the S/G peak ratio consistent with mediator attaching to the wood solids. The current investigation demonstrates the action of bacterial laccase-mediator systems directly on woody materials, and the potential of using ToF-SIMS to uncover the fundamental and applied role of bacterial enzymes in lignocellulose conversion. © 2017 Scandinavian Plant Physiology Society.

  14. Feasibility of self-sampled dried blood spot and saliva samples sent by mail in a population-based study

    International Nuclear Information System (INIS)

    Sakhi, Amrit Kaur; Bastani, Nasser Ezzatkhah; Ellingjord-Dale, Merete; Gundersen, Thomas Erik; Blomhoff, Rune; Ursin, Giske

    2015-01-01

    In large epidemiological studies it is often challenging to obtain biological samples. Self-sampling by study participants using dried blood spots (DBS) technique has been suggested to overcome this challenge. DBS is a type of biosampling where blood samples are obtained by a finger-prick lancet, blotted and dried on filter paper. However, the feasibility and efficacy of collecting DBS samples from study participants in large-scale epidemiological studies is not known. The aim of the present study was to test the feasibility and response rate of collecting self-sampled DBS and saliva samples in a population–based study of women above 50 years of age. We determined response proportions, number of phone calls to the study center with questions about sampling, and quality of the DBS. We recruited women through a study conducted within the Norwegian Breast Cancer Screening Program. Invitations, instructions and materials were sent to 4,597 women. The data collection took place over a 3 month period in the spring of 2009. Response proportions for the collection of DBS and saliva samples were 71.0% (3,263) and 70.9% (3,258), respectively. We received 312 phone calls (7% of the 4,597 women) with questions regarding sampling. Of the 3,263 individuals that returned DBS cards, 3,038 (93.1%) had been packaged and shipped according to instructions. A total of 3,032 DBS samples were sufficient for at least one biomarker analysis (i.e. 92.9% of DBS samples received by the laboratory). 2,418 (74.1%) of the DBS cards received by the laboratory were filled with blood according to the instructions (i.e. 10 completely filled spots with up to 7 punches per spot for up to 70 separate analyses). To assess the quality of the samples, we selected and measured two biomarkers (carotenoids and vitamin D). The biomarker levels were consistent with previous reports. Collecting self-sampled DBS and saliva samples through the postal services provides a low cost, effective and feasible

  15. Sampling challenges in a study examining refugee resettlement.

    Science.gov (United States)

    Sulaiman-Hill, Cheryl Mr; Thompson, Sandra C

    2011-03-15

    As almost half of all refugees currently under United Nations protection are from Afghanistan or Iraq and significant numbers have already been resettled outside the region of origin, it is likely that future research will examine their resettlement needs. A number of methodological challenges confront researchers working with culturally and linguistically diverse groups; however, few detailed articles are available to inform other studies. The aim of this paper is to outline challenges with sampling and recruitment of socially invisible refugee groups, describing the method adopted for a mixed methods exploratory study assessing mental health, subjective wellbeing and resettlement perspectives of Afghan and Kurdish refugees living in New Zealand and Australia. Sampling strategies used in previous studies with similar refugee groups were considered before determining the approach to recruitment A snowball approach was adopted for the study, with multiple entry points into the communities being used to choose as wide a range of people as possible to provide further contacts and reduce selection bias. Census data was used to assess the representativeness of the sample. A sample of 193 former refugee participants was recruited in Christchurch (n = 98) and Perth (n = 95), 47% were of Afghan and 53% Kurdish ethnicity. A good gender balance (males 52%, females 48%) was achieved overall, mainly as a result of the sampling method used. Differences in the demographic composition of groups in each location were observed, especially in relation to the length of time spent in a refugee situation and time since arrival, reflecting variations in national humanitarian quota intakes. Although some measures were problematic, Census data comparison to assess reasonable representativeness of the study sample was generally reassuring. Snowball sampling, with multiple initiation points to reduce selection bias, was necessary to locate and identify participants, provide reassurance and

  16. Sampling challenges in a study examining refugee resettlement

    Directory of Open Access Journals (Sweden)

    Thompson Sandra C

    2011-03-01

    Full Text Available Abstract Background As almost half of all refugees currently under United Nations protection are from Afghanistan or Iraq and significant numbers have already been resettled outside the region of origin, it is likely that future research will examine their resettlement needs. A number of methodological challenges confront researchers working with culturally and linguistically diverse groups; however, few detailed articles are available to inform other studies. The aim of this paper is to outline challenges with sampling and recruitment of socially invisible refugee groups, describing the method adopted for a mixed methods exploratory study assessing mental health, subjective wellbeing and resettlement perspectives of Afghan and Kurdish refugees living in New Zealand and Australia. Sampling strategies used in previous studies with similar refugee groups were considered before determining the approach to recruitment Methods A snowball approach was adopted for the study, with multiple entry points into the communities being used to choose as wide a range of people as possible to provide further contacts and reduce selection bias. Census data was used to assess the representativeness of the sample. Results A sample of 193 former refugee participants was recruited in Christchurch (n = 98 and Perth (n = 95, 47% were of Afghan and 53% Kurdish ethnicity. A good gender balance (males 52%, females 48% was achieved overall, mainly as a result of the sampling method used. Differences in the demographic composition of groups in each location were observed, especially in relation to the length of time spent in a refugee situation and time since arrival, reflecting variations in national humanitarian quota intakes. Although some measures were problematic, Census data comparison to assess reasonable representativeness of the study sample was generally reassuring. Conclusions Snowball sampling, with multiple initiation points to reduce selection bias, was

  17. Impacts of suppression on emotional responses and performance outcomes: an experience-sampling study in younger and older workers.

    Science.gov (United States)

    Yeung, Dannii Y; Fung, Helene H

    2012-11-01

    Past studies have demonstrated that older adults used less emotional suppression to regulate their emotions than did younger adults, but the effectiveness of using this emotion regulatory strategy on psychosocial well-being across age remains largely unexplored. The present study adopted an experience-sampling method to examine whether the impacts of momentary employment of emotional suppression on momentary positive and negative emotions and job performance would be different by age. Eighty-seven Chinese insurance workers, aged between 18 and 61 years, participated in a 5-day sampling study. Their affective responses at work, momentary task performance, and sales productivity were recorded. Results showed that older workers' greater use of suppression at work was associated with lower intensity of negative emotions, whereas such association was not found among younger workers. Moreover, greater use of suppression over the sampling period was significantly predictive of sales productivity of older workers, but such a positive association was not shown in younger workers. These findings reveal that the use of suppression at work may be more effective for older workers than for younger workers.

  18. Sample Size in Qualitative Interview Studies: Guided by Information Power.

    Science.gov (United States)

    Malterud, Kirsti; Siersma, Volkert Dirk; Guassora, Ann Dorrit

    2015-11-27

    Sample sizes must be ascertained in qualitative studies like in quantitative studies but not by the same means. The prevailing concept for sample size in qualitative studies is "saturation." Saturation is closely tied to a specific methodology, and the term is inconsistently applied. We propose the concept "information power" to guide adequate sample size for qualitative studies. Information power indicates that the more information the sample holds, relevant for the actual study, the lower amount of participants is needed. We suggest that the size of a sample with sufficient information power depends on (a) the aim of the study, (b) sample specificity, (c) use of established theory, (d) quality of dialogue, and (e) analysis strategy. We present a model where these elements of information and their relevant dimensions are related to information power. Application of this model in the planning and during data collection of a qualitative study is discussed. © The Author(s) 2015.

  19. Energy landscape of all-atom protein-protein interactions revealed by multiscale enhanced sampling.

    Directory of Open Access Journals (Sweden)

    Kei Moritsugu

    2014-10-01

    Full Text Available Protein-protein interactions are regulated by a subtle balance of complicated atomic interactions and solvation at the interface. To understand such an elusive phenomenon, it is necessary to thoroughly survey the large configurational space from the stable complex structure to the dissociated states using the all-atom model in explicit solvent and to delineate the energy landscape of protein-protein interactions. In this study, we carried out a multiscale enhanced sampling (MSES simulation of the formation of a barnase-barstar complex, which is a protein complex characterized by an extraordinary tight and fast binding, to determine the energy landscape of atomistic protein-protein interactions. The MSES adopts a multicopy and multiscale scheme to enable for the enhanced sampling of the all-atom model of large proteins including explicit solvent. During the 100-ns MSES simulation of the barnase-barstar system, we observed the association-dissociation processes of the atomistic protein complex in solution several times, which contained not only the native complex structure but also fully non-native configurations. The sampled distributions suggest that a large variety of non-native states went downhill to the stable complex structure, like a fast folding on a funnel-like potential. This funnel landscape is attributed to dominant configurations in the early stage of the association process characterized by near-native orientations, which will accelerate the native inter-molecular interactions. These configurations are guided mostly by the shape complementarity between barnase and barstar, and lead to the fast formation of the final complex structure along the downhill energy landscape.

  20. Generalized q-sampling imaging fiber tractography reveals displacement and infiltration of fiber tracts in low-grade gliomas

    Energy Technology Data Exchange (ETDEWEB)

    Celtikci, Pinar; Fernandes-Cabral, David T.; Yeh, Fang-Cheng; Panesar, Sandip S.; Fernandez-Miranda, Juan C. [University of Pittsburgh Medical Center, Department of Neurological Surgery, Pittsburgh, PA (United States)

    2018-03-15

    Low-grade gliomas (LGGs) are slow growing brain tumors that often cause displacement and/or infiltration of the surrounding white matter pathways. Differentiation between infiltration and displacement of fiber tracts remains a challenge. Currently, there is no reliable noninvasive imaging method capable of revealing such white matter alteration patterns. We employed quantitative anisotropy (QA) derived from generalized q-sampling imaging (GQI) to identify patterns of fiber tract alterations by LGGs. Sixteen patients with a neuropathological diagnosis of LGG (WHO grade II) were enrolled. Peritumoral fiber tracts underwent qualitative and quantitative evaluation. Contralateral hemisphere counterparts were used for comparison. Tracts were qualitatively classified as unaffected, displaced, infiltrated or displaced, and infiltrated at once. The average QA of whole tract (W), peritumoral tract segment (S), and their ratio (S/W) were obtained and compared to the healthy side for quantitative evaluation. Qualitative analysis revealed 9 (13.8%) unaffected, 24 (36.9%) displaced, 13 (20%) infiltrated, and 19 (29.2%) tracts with a combination of displacement and infiltration. There were no disrupted tracts. There was a significant increase in S/W ratio among displaced tracts in the pre-operative scans in comparison with the contralateral side. QA values of peritumoral tract segments (S) were significantly lower in infiltrated tracts. WHO grade II LGGs might displace, infiltrate, or cause a combination of displacement and infiltration of WM tracts. QA derived from GQI provides valuable information that helps to differentiate infiltration from displacement. Anisotropy changes correlate with qualitative alterations, which may serve as a potential biomarker of fiber tract integrity. (orig.)

  1. A comparison of two common sample preparation techniques for lipid and fatty acid analysis in three different coral morphotypes reveals quantitative and qualitative differences.

    Science.gov (United States)

    Conlan, Jessica A; Rocker, Melissa M; Francis, David S

    2017-01-01

    Lipids are involved in a host of biochemical and physiological processes in corals. Therefore, changes in lipid composition reflect changes in the ecology, nutrition, and health of corals. As such, accurate lipid extraction, quantification, and identification is critical to obtain comprehensive insight into a coral's condition. However, discrepancies exist in sample preparation methodology globally, and it is currently unknown whether these techniques generate analogous results. This study compared the two most common sample preparation techniques for lipid analysis in corals: (1) tissue isolation by air-spraying and (2) crushing the coral in toto . Samples derived from each preparation technique were subsequently analysed to quantify lipids and their constituent classes and fatty acids in four common, scleractinian coral species representing three distinct morphotypes ( Acropora millepora , Montipora crassotuberculata , Porites cylindrica , and Pocillopora damicornis ). Results revealed substantial amounts of organic material, including lipids, retained in the skeletons of all species following air-spraying, causing a marked underestimation of total lipid concentration using this method. Moreover, lipid class and fatty acid compositions between the denuded skeleton and sprayed tissue were substantially different. In particular, the majority of the total triacylglycerol and total fatty acid concentrations were retained in the skeleton (55-69% and 56-64%, respectively). As such, the isolated, sprayed tissue cannot serve as a reliable proxy for lipid quantification or identification in the coral holobiont. The in toto crushing method is therefore recommended for coral sample preparation prior to lipid analysis to capture the lipid profile of the entire holobiont, permitting accurate diagnoses of coral condition.

  2. A comparison of two common sample preparation techniques for lipid and fatty acid analysis in three different coral morphotypes reveals quantitative and qualitative differences

    Directory of Open Access Journals (Sweden)

    Jessica A. Conlan

    2017-08-01

    Full Text Available Lipids are involved in a host of biochemical and physiological processes in corals. Therefore, changes in lipid composition reflect changes in the ecology, nutrition, and health of corals. As such, accurate lipid extraction, quantification, and identification is critical to obtain comprehensive insight into a coral’s condition. However, discrepancies exist in sample preparation methodology globally, and it is currently unknown whether these techniques generate analogous results. This study compared the two most common sample preparation techniques for lipid analysis in corals: (1 tissue isolation by air-spraying and (2 crushing the coral in toto. Samples derived from each preparation technique were subsequently analysed to quantify lipids and their constituent classes and fatty acids in four common, scleractinian coral species representing three distinct morphotypes (Acropora millepora, Montipora crassotuberculata, Porites cylindrica, and Pocillopora damicornis. Results revealed substantial amounts of organic material, including lipids, retained in the skeletons of all species following air-spraying, causing a marked underestimation of total lipid concentration using this method. Moreover, lipid class and fatty acid compositions between the denuded skeleton and sprayed tissue were substantially different. In particular, the majority of the total triacylglycerol and total fatty acid concentrations were retained in the skeleton (55–69% and 56–64%, respectively. As such, the isolated, sprayed tissue cannot serve as a reliable proxy for lipid quantification or identification in the coral holobiont. The in toto crushing method is therefore recommended for coral sample preparation prior to lipid analysis to capture the lipid profile of the entire holobiont, permitting accurate diagnoses of coral condition.

  3. Comparison at the peptide level with post-translational modification consideration reveals more differences between two unenriched samples.

    Science.gov (United States)

    Yin, Jianrui; Shao, Chen; Jia, Lulu; Gao, Youhe

    2014-06-30

    In shotgun strategies, peptide sequences are first identified from tandem mass (MS/MS) spectra, and the existence and abundance of the proteins are then inferred from the peptide information. However, the protein inference step can produce errors and a loss of information. To identify the information that is lost using the traditional approaches, this study compared the proteomic data of two leukemia cell lines (Jurkat and K562) at the peptide level with consideration of post-translational modifications (PTMs). The raw files from the two cell lines were searched against the decoy IPI-human database version 3.68, which contains forward and reverse sequences. Then the observed modification name in the results was matched with the modification classification on the Unimod website by a manual search. Only the peptides with 'post-translational' modifications were compared between the two cell lines. After searching the database with consideration of PTMs, a total of 44046 non-redundant peptides were identified in both the Jurkat and K562 cell lines. Of these peptides, even without specific PTM enrichment, 11.43% of them (with at least two spectra in one cell line) existed in different PTM forms between the two cell lines, and 1.73% of the peptides were modified in both cell lines, but with different modifications or possibly on different sites. Comparing proteomic data at the peptide level with consideration of PTMs can reveal more differences between two unenriched samples. Copyright © 2014 John Wiley & Sons, Ltd.

  4. Attenuation of species abundance distributions by sampling

    Science.gov (United States)

    Shimadzu, Hideyasu; Darnell, Ross

    2015-01-01

    Quantifying biodiversity aspects such as species presence/ absence, richness and abundance is an important challenge to answer scientific and resource management questions. In practice, biodiversity can only be assessed from biological material taken by surveys, a difficult task given limited time and resources. A type of random sampling, or often called sub-sampling, is a commonly used technique to reduce the amount of time and effort for investigating large quantities of biological samples. However, it is not immediately clear how (sub-)sampling affects the estimate of biodiversity aspects from a quantitative perspective. This paper specifies the effect of (sub-)sampling as attenuation of the species abundance distribution (SAD), and articulates how the sampling bias is induced to the SAD by random sampling. The framework presented also reveals some confusion in previous theoretical studies. PMID:26064626

  5. DNA cards: determinants of DNA yield and quality in collecting genetic samples for pharmacogenetic studies.

    Science.gov (United States)

    Mas, Sergi; Crescenti, Anna; Gassó, Patricia; Vidal-Taboada, Jose M; Lafuente, Amalia

    2007-08-01

    As pharmacogenetic studies frequently require establishment of DNA banks containing large cohorts with multi-centric designs, inexpensive methods for collecting and storing high-quality DNA are needed. The aims of this study were two-fold: to compare the amount and quality of DNA obtained from two different DNA cards (IsoCode Cards or FTA Classic Cards, Whatman plc, Brentford, Middlesex, UK); and to evaluate the effects of time and storage temperature, as well as the influence of anticoagulant ethylenediaminetetraacetic acid on the DNA elution procedure. The samples were genotyped by several methods typically used in pharmacogenetic studies: multiplex PCR, PCR-restriction fragment length polymorphism, single nucleotide primer extension, and allelic discrimination assay. In addition, they were amplified by whole genome amplification to increase genomic DNA mass. Time, storage temperature and ethylenediaminetetraacetic acid had no significant effects on either DNA card. This study reveals the importance of drying blood spots prior to isolation to avoid haemoglobin interference. Moreover, our results demonstrate that re-isolation protocols could be applied to increase the amount of DNA recovered. The samples analysed were accurately genotyped with all the methods examined herein. In conclusion, our study shows that both DNA cards, IsoCode Cards and FTA Classic Cards, facilitate genetic and pharmacogenetic testing for routine clinical practice.

  6. Developing Sampling Frame for Case Study: Challenges and Conditions

    Science.gov (United States)

    Ishak, Noriah Mohd; Abu Bakar, Abu Yazid

    2014-01-01

    Due to statistical analysis, the issue of random sampling is pertinent to any quantitative study. Unlike quantitative study, the elimination of inferential statistical analysis, allows qualitative researchers to be more creative in dealing with sampling issue. Since results from qualitative study cannot be generalized to the bigger population,…

  7. Statistical sampling strategies

    International Nuclear Information System (INIS)

    Andres, T.H.

    1987-01-01

    Systems assessment codes use mathematical models to simulate natural and engineered systems. Probabilistic systems assessment codes carry out multiple simulations to reveal the uncertainty in values of output variables due to uncertainty in the values of the model parameters. In this paper, methods are described for sampling sets of parameter values to be used in a probabilistic systems assessment code. Three Monte Carlo parameter selection methods are discussed: simple random sampling, Latin hypercube sampling, and sampling using two-level orthogonal arrays. Three post-selection transformations are also described: truncation, importance transformation, and discretization. Advantages and disadvantages of each method are summarized

  8. Preliminary Beneficiation and Washability Studies on Ghouzlou's Low-Ash Coal Sample

    Directory of Open Access Journals (Sweden)

    Ataallah Bahrami

    2017-12-01

    Full Text Available In the present research work, a low-ash coal, from Ghouzlou deposit in Iran, with an average ash content of 12% was subjected to some beneficiation experiments such as heavy media separation and flotation. Sieve analysis showed that 62.3% of the coal sample with the size of +2 mm had around 7.3% ash contents. Also, heavy media tests carried out on five size fractions revealed that by setting the separation density at 1.4 g/cm3 for the coarse fraction (+1 mm, a 5% ash product with more than 70% coal recovery was obtainable. Samples with lower ash content (5% based on the Mayer curves to produce a 5% coal product. Moreover, flotation tests on -1 mm fraction could reduce the ash content from more 13.2% to 10.4%.

  9. High-risk human papillomavirus (HPV screening and detection in healthy patient saliva samples: a pilot study

    Directory of Open Access Journals (Sweden)

    Wang Robert C

    2011-10-01

    Full Text Available Abstract Background The human papillomaviruses (HPV are a large family of non-enveloped DNA viruses, mainly associated with cervical cancers. Recent epidemiologic evidence has suggested that HPV may be an independent risk factor for oropharyngeal cancers. Evidence now suggests HPV may modulate the malignancy process in some tobacco- and alcohol-induced oropharynx tumors, but might also be the primary oncogenic factor for inducing carcinogenesis among some non-smokers. More evidence, however, is needed regarding oral HPV prevalence among healthy adults to estimate risk. The goal of this study was to perform an HPV screening of normal healthy adults to assess oral HPV prevalence. Methods Healthy adult patients at a US dental school were selected to participate in this pilot study. DNA was isolated from saliva samples and screened for high-risk HPV strains HPV16 and HPV18 and further processed using qPCR for quantification and to confirm analytical sensitivity and specificity. Results Chi-square analysis revealed the patient sample was representative of the general clinic population with respect to gender, race and age (p Conclusions The successful recruitment and screening of healthy adult patients revealed HPV16, but not HPV18, was present in a small subset. These results provide new information about oral HPV status, which may help to contextualize results from other studies that demonstrate oral cancer rates have risen in the US among both females and minorities and in some geographic areas that are not solely explained by rates of tobacco and alcohol use. The results of this study may be of significant value to further our understanding of oral health and disease risk, as well as to help design future studies exploring the role of other factors that influence oral HPV exposure, as well as the short- and long-term consequences of oral HPV infection.

  10. Landmark Study Reveals Antarctic Glacier's Long History of Retreat

    OpenAIRE

    Kuska, Dale M.

    2016-01-01

    Faculty Showcase Archive Article Approved for public release; distribution is unlimited. A major study, released in late November in the journal “Nature,” reveals the history of retreat of the massive Pine Island Glacier (PIG) in western Antarctica, widely considered one of the largest contributors to global sea-level rise.

  11. Sampling pig farms at the abattoir in a cross-sectional study − Evaluation of a sampling method

    DEFF Research Database (Denmark)

    Birkegård, Anna Camilla; Hisham Beshara Halasa, Tariq; Toft, Nils

    2017-01-01

    slaughter pigs. It was not possible to visit farms within the designated timeframe. Therefore, it was decided to use convenience sampling at the abattoir. Our approach was carried out in three steps: 1) planning: using data from meat inspection to plan at which abattoirs and how many farms to sample; 2......A cross-sectional study design is relatively inexpensive, fast and easy to conduct when compared to other study designs. Careful planning is essential to obtaining a representative sample of the population, and the recommended approach is to use simple random sampling from an exhaustive list...... of units in the target population. This approach is rarely feasible in practice, and other sampling procedures must often be adopted. For example, when slaughter pigs are the target population, sampling the pigs on the slaughter line may be an alternative to on-site sampling at a list of farms. However...

  12. The UK Biobank sample handling and storage validation studies.

    Science.gov (United States)

    Peakman, Tim C; Elliott, Paul

    2008-04-01

    and aims UK Biobank is a large prospective study in the United Kingdom to investigate the role of genetic factors, environmental exposures and lifestyle in the causes of major diseases of late and middle age. It involves the collection of blood and urine from 500 000 individuals aged between 40 and 69 years. How the samples are collected, processed and stored will have a major impact on the future scientific usefulness of the UK Biobank resource. A series of validation studies was recommended to test the robustness of the draft sample handling and storage protocol. Samples of blood and urine were collected from 40 healthy volunteers and either processed immediately according to the protocol or maintained at specified temperatures (4 degrees C for all tubes with the exception of vacutainers containing acid citrate dextrose that were maintained at 18 degrees C) for 12, 24 or 36 h prior to processing. A further sample was maintained for 24 h at 4 degrees C, processed and the aliquots frozen at -80 degrees C for 20 days and then thawed under controlled conditions. The stability of the samples was compared for the different times in a wide variety of assays. The samples maintained at 4 degrees C were stable for at least 24 h after collection for a wide range of assays. Small but significant changes were observed in metabonomic studies in samples maintained at 4 degrees C for 36 h. There was no degradation of the samples for a range of biochemical assays after short-term freezing and thawing under controlled conditions. Whole blood maintained at 18 degrees C for 24 h in vacutainers containing acid citrate dextrose is suitable for viral immortalization techniques. The validation studies reported in this supplement provide justification for the sample handling and storage procedures adopted in the UK Biobank project.

  13. Statistics and sampling in transuranic studies

    International Nuclear Information System (INIS)

    Eberhardt, L.L.; Gilbert, R.O.

    1980-01-01

    The existing data on transuranics in the environment exhibit a remarkably high variability from sample to sample (coefficients of variation of 100% or greater). This chapter stresses the necessity of adequate sample size and suggests various ways to increase sampling efficiency. Objectives in sampling are regarded as being of great importance in making decisions as to sampling methodology. Four different classes of sampling methods are described: (1) descriptive sampling, (2) sampling for spatial pattern, (3) analytical sampling, and (4) sampling for modeling. A number of research needs are identified in the various sampling categories along with several problems that appear to be common to two or more such areas

  14. Estimating sample size for landscape-scale mark-recapture studies of North American migratory tree bats

    Science.gov (United States)

    Ellison, Laura E.; Lukacs, Paul M.

    2014-01-01

    Concern for migratory tree-roosting bats in North America has grown because of possible population declines from wind energy development. This concern has driven interest in estimating population-level changes. Mark-recapture methodology is one possible analytical framework for assessing bat population changes, but sample size requirements to produce reliable estimates have not been estimated. To illustrate the sample sizes necessary for a mark-recapture-based monitoring program we conducted power analyses using a statistical model that allows reencounters of live and dead marked individuals. We ran 1,000 simulations for each of five broad sample size categories in a Burnham joint model, and then compared the proportion of simulations in which 95% confidence intervals overlapped between and among years for a 4-year study. Additionally, we conducted sensitivity analyses of sample size to various capture probabilities and recovery probabilities. More than 50,000 individuals per year would need to be captured and released to accurately determine 10% and 15% declines in annual survival. To detect more dramatic declines of 33% or 50% survival over four years, then sample sizes of 25,000 or 10,000 per year, respectively, would be sufficient. Sensitivity analyses reveal that increasing recovery of dead marked individuals may be more valuable than increasing capture probability of marked individuals. Because of the extraordinary effort that would be required, we advise caution should such a mark-recapture effort be initiated because of the difficulty in attaining reliable estimates. We make recommendations for what techniques show the most promise for mark-recapture studies of bats because some techniques violate the assumptions of mark-recapture methodology when used to mark bats.

  15. Fecal steroid hormones reveal reproductive state in female blue whales sampled in the Gulf of California, Mexico.

    Science.gov (United States)

    Valenzuela-Molina, Marcia; Atkinson, Shannon; Mashburn, Kendall; Gendron, Diane; Brownell, Robert L

    2018-05-15

    Steroid hormone assessment using non-invasive sample collection techniques can reveal the reproductive status of aquatic mammals and the physiological mechanisms by which they respond to changes in their environment. A portion of the eastern North Pacific blue whale (Balaenoptera musculus) population that seasonally visits the Gulf of California, Mexico has been monitored using photo-identified individuals for over 30 years. The whales use the area in winter-early spring for nursing their calves and feeding and it therefore is well suited for fecal sample collection. Using radioimmunoassays in 25 fecal samples collected between 2009 and 2012 to determine reproductive state and stress, we validated three steroid hormones (progesterone, corticosterone and cortisol) in adult female blue whales. Females that were categorized as pregnant had higher mean fecal progesterone metabolite concentrations (1292.6 ± 415.6 ng·g -1 ) than resting and lactating females (14.0 ± 3.7 ng·g -1 ; 23.0 ± 5.4 ng·g -1 , respectively). Females classified as pregnant also had higher concentrations of corticosterone metabolites (37.5 ± 9.9 ng·g -1 ) than resting and lactating females (17.4 ± 2.0 ng·g -1 ; 16.8 ± 2.8 ng·g -1 , respectively). In contrast, cortisol metabolite concentrations showed high variability between groups and no significant relationship to reproductive state. We successfully determined preliminary baseline parameters of key steroid hormones by reproductive state in adult female blue whales. The presence of pregnant or with luteal activity and known lactating females confirms that the Gulf of California is an important winter-spring area for the reproductive phase of these blue whales. The baseline corticosterone levels we are developing will be useful for assessing the impact of the increasing coastal development and whale-watching activities on the whales in the Gulf of California. Copyright © 2018 Elsevier Inc. All

  16. An integrated rock magnetic and EPR study in soil samples from a hydrocarbon prospective area

    Science.gov (United States)

    González, F.; Aldana, M.; Costanzo-Álvarez, V.; Díaz, M.; Romero, I.

    Magnetic susceptibility (MS) and organic matter free radical concentration (OMFRC) determined by electron paramagnetic resonance, have been measured in soil samples (≈1.5 m depth) from an oil prospective area located at the southern flank of the Venezuelan Andean Range. S-ratios close to 1, as well as high temperature susceptibility analyses, reveal magnetite as the chief magnetic phase in most of these samples. Ethane concentrations, MS and OMFRC normalized data have been plotted against the relative position of 22 sampling sites sequentially arranged from north to south. Although there is not a linear correlation between MS and OMFRC data, these two profiles seem to vary in like fashion. A MS and OMFRC southern anomaly coincides with the zone of highest ethane concentration that overlies a “Cretaceous kitchen”. OMFRC highs could be linked to the degradation or alteration of organic matter, the possible result of hydrocarbon gas leakage, whose surface expression is the stressed fern observed by remote sensing studies previously performed in the area. Ethane anomalies are associated to this seepage that also produces changes in the magnetic mineralogies detected as MS positive anomalies.

  17. Random sampling of the Central European bat fauna reveals the existence of numerous hitherto unknown adenoviruses.

    Science.gov (United States)

    Vidovszky, Márton; Kohl, Claudia; Boldogh, Sándor; Görföl, Tamás; Wibbelt, Gudrun; Kurth, Andreas; Harrach, Balázs

    2015-12-01

    From over 1250 extant species of the order Chiroptera, 25 and 28 are known to occur in Germany and Hungary, respectively. Close to 350 samples originating from 28 bat species (17 from Germany, 27 from Hungary) were screened for the presence of adenoviruses (AdVs) using a nested PCR that targets the DNA polymerase gene of AdVs. An additional PCR was designed and applied to amplify a fragment from the gene encoding the IVa2 protein of mastadenoviruses. All German samples originated from organs of bats found moribund or dead. The Hungarian samples were excrements collected from colonies of known bat species, throat or rectal swab samples, taken from live individuals that had been captured for faunistic surveys and migration studies, as well as internal organs of dead specimens. Overall, 51 samples (14.73%) were found positive. We detected 28 seemingly novel and six previously described bat AdVs by sequencing the PCR products. The positivity rate was the highest among the guano samples of bat colonies. In phylogeny reconstructions, the AdVs detected in bats clustered roughly, but not perfectly, according to the hosts' families (Vespertilionidae, Rhinolophidae, Hipposideridae, Phyllostomidae and Pteropodidae). In a few cases, identical sequences were derived from animals of closely related species. On the other hand, some bat species proved to harbour more than one type of AdV. The high prevalence of infection and the large number of chiropteran species worldwide make us hypothesise that hundreds of different yet unknown AdV types might circulate in bats.

  18. Genotyping of Toxoplasma Gondii Isolates from Soil Samples in Tehran, Iran

    Directory of Open Access Journals (Sweden)

    M Tavalla

    2013-06-01

    Full Text Available Background: The protozoan parasite Toxoplasma gondii can infect any warm blooded nucleated cells. One of the ways for human infection is ingestion of oocysts directly from soil or via infected fruits or vegetables. To survey the potential role of T. gondii oocyst in soil samples, the present study was conducted in Tehran City, Iran.Methods: A total of 150 soil samples were collected around rubbish dumps, children's play ground, parks and public places. Oocysts recovery was performed by sodium nitrate flotation method on soil samples. For molecular detection, PCR reaction targeting B1 gene was performed and then, the posi­tive results were confirmed using repetitive 529 bp DNA fragment in other PCR reaction. Finally, the positive samples were genotyped at the SAG2 locus.Results: Toxoplasma DNA was found in 13 soil samples. After genotyping and RFLP analysis in SAG2 locus, nine positive samples were revealed type III, one positive sample was type I whereas three samples revealed mixed infection (type, I & III.Conclusion: The predominant genotype in Tehran soil samples is type III.

  19. Multielemental analysis of samples from patients with dermatological pathologies using synchrotron radiation

    International Nuclear Information System (INIS)

    Soares, J.C.A.C.R.; Canellas, C.G.L.; Anjos, M.J.; Lopes, R.T.

    2014-01-01

    Using synchrotron radiation total X-ray fluorescence (SRTXRF) technique, the concentrations of trace elements were measured in four skin lesions: seborrheic keratosis, fibroepithelial polyp, cherry angioma and dermatosis papulosa nigra. The concentrations of P, S, K, Ca, Fe, Cu, Zn and Rb were evaluated in 62 pairs of lesions and healthy samples, each one having been collected from the same patient. The results revealed significant differences of P, Ca, K, Fe and Cu levels as well as a common trend in their variations between lesion and control samples among the skin diseases. This study revealed a powerful tool that can be useful for skin disorders research. The measurements were conducted at Brazilian National Synchrotron Light Laboratory (LNLS). - Highlights: • Concentrations of trace elements were measured and compared in four skin lesions. • The results revealed significant differences of P, Ca, K, Fe and Cu levels. • This study revealed a powerful tool that can be useful for skin disorders research

  20. Multiscale study on stochastic reconstructions of shale samples

    Science.gov (United States)

    Lili, J.; Lin, M.; Jiang, W. B.

    2016-12-01

    Shales are known to have multiscale pore systems, composed of macroscale fractures, micropores, and nanoscale pores within gas or oil-producing organic material. Also, shales are fissile and laminated, and the heterogeneity in horizontal is quite different from that in vertical. Stochastic reconstructions are extremely useful in situations where three-dimensional information is costly and time consuming. Thus the purpose of our paper is to reconstruct stochastically equiprobable 3D models containing information from several scales. In this paper, macroscale and microscale images of shale structure in the Lower Silurian Longmaxi are obtained by X-ray microtomography and nanoscale images are obtained by scanning electron microscopy. Each image is representative for all given scales and phases. Especially, the macroscale is four times coarser than the microscale, which in turn is four times lower in resolution than the nanoscale image. Secondly, the cross correlation-based simulation method (CCSIM) and the three-step sampling method are combined together to generate stochastic reconstructions for each scale. It is important to point out that the boundary points of pore and matrix are selected based on multiple-point connectivity function in the sampling process, and thus the characteristics of the reconstructed image can be controlled indirectly. Thirdly, all images with the same resolution are developed through downscaling and upscaling by interpolation, and then we merge multiscale categorical spatial data into a single 3D image with predefined resolution (the microscale image). 30 realizations using the given images and the proposed method are generated. The result reveals that the proposed method is capable of preserving the multiscale pore structure, both vertically and horizontally, which is necessary for accurate permeability prediction. The variogram curves and pore-size distribution for both original 3D sample and the generated 3D realizations are compared

  1. Population Screening Using Sewage Reveals Pan-Resistant Bacteria in Hospital and Community Samples.

    Science.gov (United States)

    Meir-Gruber, Lital; Manor, Yossi; Gefen-Halevi, Shiraz; Hindiyeh, Musa Y; Mileguir, Fernando; Azar, Roberto; Smollan, Gill; Belausov, Natasha; Rahav, Galia; Shamiss, Ari; Mendelson, Ella; Keller, Nathan

    2016-01-01

    The presence of pan-resistant bacteria worldwide possesses a threat to global health. It is difficult to evaluate the extent of carriage of resistant bacteria in the population. Sewage sampling is a possible way to monitor populations. We evaluated the presence of pan-resistant bacteria in Israeli sewage collected from all over Israel, by modifying the pour plate method for heterotrophic plate count technique using commercial selective agar plates. This method enables convenient and fast sewage sampling and detection. We found that sewage in Israel contains multiple pan-resistant bacteria including carbapenemase resistant Enterobacteriacae carrying blaKPC and blaNDM-1, MRSA and VRE. blaKPC carrying Klebsiella pneumonia and Enterobacter cloacae were the most common Enterobacteriacae drug resistant bacteria found in the sewage locations we sampled. Klebsiella pneumonia, Enterobacter spp., Escherichia coli and Citrobacter spp. were the 4 main CRE isolated from Israeli sewage and also from clinical samples in our clinical microbiology laboratory. Hospitals and Community sewage had similar percentage of positive samplings for blaKPC and blaNDM-1. VRE was found to be more abundant in sewage in Israel than MRSA but there were more locations positive for MRSA and VRE bacteria in Hospital sewage than in the Community. Therefore, our upgrade of the pour plate method for heterotrophic plate count technique using commercial selective agar plates can be a useful tool for routine screening and monitoring of the population for pan-resistant bacteria using sewage.

  2. Self-collected cervicovaginal sampling for site-of-care primary HPV-based cervical cancer screening: a pilot study in a rural underserved Greek population.

    Science.gov (United States)

    Chatzistamatiou, Kimon; Chatzaki, Εkaterini; Constantinidis, Τheocharis; Nena, Evangelia; Tsertanidou, Athena; Agorastos, Theodoros

    2017-11-01

    In the present pilot study, the feasibility of a site-of-care cervicovaginal self-sampling methodology for HPV-based screening was tested in 346 women residing in underserved rural areas of Northern Greece. These women provided self-collected cervicovaginal sample along with a study questionnaire. Following molecular testing, using the cobas ® HPV Test, Roche ® , HPV positive women, were referred to colposcopy and upon abnormal findings, to biopsy and treatment. Participation rate was 100%. Regular pap-test examination was reported for 17.1%. Among hrHPV testing, 11.9% were positive and colposcopy/biopsy revealed 2 CIN3 cases. Non-compliance was the most prevalent reason for no previous attendance. Most women reported non-difficulty and non-discomfort in self-sampling (77.6% and 82.4%, respectively). They would choose self-sampling over clinician-sampling (86.2%), and should self-sampling being available, they would test themselves more regularly (92.3%). In conclusion, self-sampling is feasible and well-accepted for HPV-based screening, and could increase population coverage in underserved areas, helping towards successful prevention.

  3. Bacterial diversity characterization in petroleum samples from Brazilian reservoirs

    Science.gov (United States)

    de Oliveira, Valéria Maia; Sette, Lara Durães; Simioni, Karen Christina Marques; dos Santos Neto, Eugênio Vaz

    2008-01-01

    This study aimed at evaluating potential differences among the bacterial communities from formation water and oil samples originated from biodegraded and non-biodegraded Brazilian petroleum reservoirs by using a PCR-DGGE based approach. Environmental DNA was isolated and used in PCR reactions with bacterial primers, followed by separation of 16S rDNA fragments in the DGGE. PCR products were also cloned and sequenced, aiming at the taxonomic affiliation of the community members. The fingerprints obtained allowed the direct comparison among the bacterial communities from oil samples presenting distinct degrees of biodegradation, as well as between the communities of formation water and oil sample from the non-biodegraded reservoir. Very similar DGGE band profiles were observed for all samples, and the diversity of the predominant bacterial phylotypes was shown to be low. Cloning and sequencing results revealed major differences between formation water and oil samples from the non-biodegraded reservoir. Bacillus sp. and Halanaerobium sp. were shown to be the predominant components of the bacterial community from the formation water sample, whereas the oil sample also included Alicyclobacillus acidoterrestris, Rhodococcus sp., Streptomyces sp. and Acidithiobacillus ferrooxidans. The PCR-DGGE technique, combined with cloning and sequencing of PCR products, revealed the presence of taxonomic groups not found previously in these samples when using cultivation-based methods and 16S rRNA gene library assembly, confirming the need of a polyphasic study in order to improve the knowledge of the extent of microbial diversity in such extreme environments. PMID:24031244

  4. Reasons for smoking among male teenagers in tehran, iran: two case-control studies using snowball sampling.

    Science.gov (United States)

    Rezaei, Fatemeh; Nedjat, Saharnaz; Golestan, Banafsheh; Majdzadeh, Reza

    2011-10-01

    Identifying the underlying factors contributing to smoking among teenagers is important in establishing smoking control programs. The present study was designed to identify and compare factors revealed in a preceding qualitative study conducted on 13-15 year-old boys living in two different socio-economic districts in the Northern and Southern parts of Tehran. Two completely similar case-control studies, each with 200 subjects, were conducted using a snowball sampling. The case and control subjects were matched based on the intimacy relations, i.e. six smokers were recruited in each of the Northern and Southern districts; they were then asked to introduce one of their smoker friends as a case and a non-smoker one as a control. Multi-variable conditional logistic regression revealed that having a smoker father is the single effective factor in the two districts. As for boys living in the Northern (wealthier) part of the city, social capital (OR: 0.59, 95% CI: 0.43-0.81) played a protective role against smoking, whereas quitting home after a quarrel (OR: 15.07, 95% CI: 1.54-147.25), monthly allowance (OR: 2.22, 95% CI: 1.29-3.82) and hyperactivity (OR: 1.69, 95% CI: 2.64-240.45) were associated with a higher risk of becoming a smoker. The studied variables can be classified as personal, familial, and school-level factors. Familial intervention is effective for all the factors which revealed to be influential on the risk of becoming a smoker. It could be concluded that interventions on the family level should be used to prevent the cigarette use in Tehran.

  5. Increased taxon sampling reveals thousands of hidden orthologs in flatworms

    Science.gov (United States)

    2017-01-01

    Gains and losses shape the gene complement of animal lineages and are a fundamental aspect of genomic evolution. Acquiring a comprehensive view of the evolution of gene repertoires is limited by the intrinsic limitations of common sequence similarity searches and available databases. Thus, a subset of the gene complement of an organism consists of hidden orthologs, i.e., those with no apparent homology to sequenced animal lineages—mistakenly considered new genes—but actually representing rapidly evolving orthologs or undetected paralogs. Here, we describe Leapfrog, a simple automated BLAST pipeline that leverages increased taxon sampling to overcome long evolutionary distances and identify putative hidden orthologs in large transcriptomic databases by transitive homology. As a case study, we used 35 transcriptomes of 29 flatworm lineages to recover 3427 putative hidden orthologs, some unidentified by OrthoFinder and HaMStR, two common orthogroup inference algorithms. Unexpectedly, we do not observe a correlation between the number of putative hidden orthologs in a lineage and its “average” evolutionary rate. Hidden orthologs do not show unusual sequence composition biases that might account for systematic errors in sequence similarity searches. Instead, gene duplication with divergence of one paralog and weak positive selection appear to underlie hidden orthology in Platyhelminthes. By using Leapfrog, we identify key centrosome-related genes and homeodomain classes previously reported as absent in free-living flatworms, e.g., planarians. Altogether, our findings demonstrate that hidden orthologs comprise a significant proportion of the gene repertoire in flatworms, qualifying the impact of gene losses and gains in gene complement evolution. PMID:28400424

  6. Sampling Key Populations for HIV Surveillance: Results From Eight Cross-Sectional Studies Using Respondent-Driven Sampling and Venue-Based Snowball Sampling.

    Science.gov (United States)

    Rao, Amrita; Stahlman, Shauna; Hargreaves, James; Weir, Sharon; Edwards, Jessie; Rice, Brian; Kochelani, Duncan; Mavimbela, Mpumelelo; Baral, Stefan

    2017-10-20

    In using regularly collected or existing surveillance data to characterize engagement in human immunodeficiency virus (HIV) services among marginalized populations, differences in sampling methods may produce different pictures of the target population and may therefore result in different priorities for response. The objective of this study was to use existing data to evaluate the sample distribution of eight studies of female sex workers (FSW) and men who have sex with men (MSM), who were recruited using different sampling approaches in two locations within Sub-Saharan Africa: Manzini, Swaziland and Yaoundé, Cameroon. MSM and FSW participants were recruited using either respondent-driven sampling (RDS) or venue-based snowball sampling. Recruitment took place between 2011 and 2016. Participants at each study site were administered a face-to-face survey to assess sociodemographics, along with the prevalence of self-reported HIV status, frequency of HIV testing, stigma, and other HIV-related characteristics. Crude and RDS-adjusted prevalence estimates were calculated. Crude prevalence estimates from the venue-based snowball samples were compared with the overlap of the RDS-adjusted prevalence estimates, between both FSW and MSM in Cameroon and Swaziland. RDS samples tended to be younger (MSM aged 18-21 years in Swaziland: 47.6% [139/310] in RDS vs 24.3% [42/173] in Snowball, in Cameroon: 47.9% [99/306] in RDS vs 20.1% [52/259] in Snowball; FSW aged 18-21 years in Swaziland 42.5% [82/325] in RDS vs 8.0% [20/249] in Snowball; in Cameroon 15.6% [75/576] in RDS vs 8.1% [25/306] in Snowball). They were less educated (MSM: primary school completed or less in Swaziland 42.6% [109/310] in RDS vs 4.0% [7/173] in Snowball, in Cameroon 46.2% [138/306] in RDS vs 14.3% [37/259] in Snowball; FSW: primary school completed or less in Swaziland 86.6% [281/325] in RDS vs 23.9% [59/247] in Snowball, in Cameroon 87.4% [520/576] in RDS vs 77.5% [238/307] in Snowball) than the snowball

  7. Selenium isotope studies in plants. Development and validation of a novel geochemical tool and its application to organic samples

    Energy Technology Data Exchange (ETDEWEB)

    Banning, Helena

    2016-03-12

    Selenium (Se), being an essential nutrient and a toxin, enters the food chain mainly via plants. Selenium isotope signatures were proved to be an excellent redox tracer, making it a promising tool for the exploration of the Se cycle in plants. The analytical method is sensitive on organic samples and requires particular preparation methods, which were developed and validated in this study. Plant cultivation setups revealed the applicability of these methods to trace plant internal processes.

  8. DNA-methylation profiling of fetal tissues reveals marked epigenetic differences between chorionic and amniotic samples.

    Directory of Open Access Journals (Sweden)

    Christel Eckmann-Scholz

    Full Text Available Epigenetic mechanisms including DNA methylation are supposed to play a key role in fetal development. Here we have investigated fetal DNA-methylation levels of 27,578 CpG loci in 47 chorionic villi (CVS and 16 amniotic cell (AC samples. Methylation levels differed significantly between karyotypically normal AC and CVS for 2,014 genes. AC showed more extreme DNA-methylation levels of these genes than CVS and the differentially methylated genes are significantly enriched for processes characteristic for the different cell types sampled. Furthermore, we identified 404 genes differentially methylated in CVS with trisomy 21. These genes were significantly enriched for high CG dinucleotid (CpG content and developmental processes associated with Down syndrome. Our study points to major tissue-specific differences of fetal DNA-methylation and gives rise to the hypothesis that part of the Down syndrome phenotype is epigenetically programmed in the first trimester of pregnancy.

  9. Social Studies Teachers' Viewpoints of the Social Studies Lesson "Sample of Turkey and Afghanistan"

    Science.gov (United States)

    Sonmez, Omer Faruk

    2014-01-01

    This study was conducted to reveal the perceptions of history, geography and social studies teachers giving the social studies lesson at primary schools in Turkey and Afghanistan towards the social studies lesson. The working group of the study involves history, geography and social studies teachers rendering service in Tokat and Kayseri provinces…

  10. Sample size estimation and sampling techniques for selecting a representative sample

    Directory of Open Access Journals (Sweden)

    Aamir Omair

    2014-01-01

    Full Text Available Introduction: The purpose of this article is to provide a general understanding of the concepts of sampling as applied to health-related research. Sample Size Estimation: It is important to select a representative sample in quantitative research in order to be able to generalize the results to the target population. The sample should be of the required sample size and must be selected using an appropriate probability sampling technique. There are many hidden biases which can adversely affect the outcome of the study. Important factors to consider for estimating the sample size include the size of the study population, confidence level, expected proportion of the outcome variable (for categorical variables/standard deviation of the outcome variable (for numerical variables, and the required precision (margin of accuracy from the study. The more the precision required, the greater is the required sample size. Sampling Techniques: The probability sampling techniques applied for health related research include simple random sampling, systematic random sampling, stratified random sampling, cluster sampling, and multistage sampling. These are more recommended than the nonprobability sampling techniques, because the results of the study can be generalized to the target population.

  11. An Optimization Study on Listening Experiments to Improve the Comparability of Annoyance Ratings of Noise Samples from Different Experimental Sample Sets.

    Science.gov (United States)

    Di, Guoqing; Lu, Kuanguang; Shi, Xiaofan

    2018-03-08

    Annoyance ratings obtained from listening experiments are widely used in studies on health effect of environmental noise. In listening experiments, participants usually give the annoyance rating of each noise sample according to its relative annoyance degree among all samples in the experimental sample set if there are no reference sound samples, which leads to poor comparability between experimental results obtained from different experimental sample sets. To solve this problem, this study proposed to add several pink noise samples with certain loudness levels into experimental sample sets as reference sound samples. On this basis, the standard curve between logarithmic mean annoyance and loudness level of pink noise was used to calibrate the experimental results and the calibration procedures were described in detail. Furthermore, as a case study, six different types of noise sample sets were selected to conduct listening experiments using this method to examine the applicability of it. Results showed that the differences in the annoyance ratings of each identical noise sample from different experimental sample sets were markedly decreased after calibration. The determination coefficient ( R ²) of linear fitting functions between psychoacoustic annoyance (PA) and mean annoyance (MA) of noise samples from different experimental sample sets increased obviously after calibration. The case study indicated that the method above is applicable to calibrating annoyance ratings obtained from different types of noise sample sets. After calibration, the comparability of annoyance ratings of noise samples from different experimental sample sets can be distinctly improved.

  12. Sampling in ecology and evolution - bridging the gap between theory and practice

    Science.gov (United States)

    Albert, C.H.; Yoccoz, N.G.; Edwards, T.C.; Graham, C.H.; Zimmermann, N.E.; Thuiller, W.

    2010-01-01

    Sampling is a key issue for answering most ecological and evolutionary questions. The importance of developing a rigorous sampling design tailored to specific questions has already been discussed in the ecological and sampling literature and has provided useful tools and recommendations to sample and analyse ecological data. However, sampling issues are often difficult to overcome in ecological studies due to apparent inconsistencies between theory and practice, often leading to the implementation of simplified sampling designs that suffer from unknown biases. Moreover, we believe that classical sampling principles which are based on estimation of means and variances are insufficient to fully address many ecological questions that rely on estimating relationships between a response and a set of predictor variables over time and space. Our objective is thus to highlight the importance of selecting an appropriate sampling space and an appropriate sampling design. We also emphasize the importance of using prior knowledge of the study system to estimate models or complex parameters and thus better understand ecological patterns and processes generating these patterns. Using a semi-virtual simulation study as an illustration we reveal how the selection of the space (e.g. geographic, climatic), in which the sampling is designed, influences the patterns that can be ultimately detected. We also demonstrate the inefficiency of common sampling designs to reveal response curves between ecological variables and climatic gradients. Further, we show that response-surface methodology, which has rarely been used in ecology, is much more efficient than more traditional methods. Finally, we discuss the use of prior knowledge, simulation studies and model-based designs in defining appropriate sampling designs. We conclude by a call for development of methods to unbiasedly estimate nonlinear ecologically relevant parameters, in order to make inferences while fulfilling requirements of

  13. The dynamics of attachment insecurity and paranoid thoughts: An experience sampling study.

    Science.gov (United States)

    Sitko, Katarzyna; Varese, Filippo; Sellwood, William; Hammond, Amy; Bentall, Richard

    2016-12-30

    It has been proposed that insecure attachment can have adverse effects on the course of psychosis once symptoms have emerged. There is longitudinal evidence that increased insecure attachment is associated with increased severity of psychotic symptoms. The present study examined whether in the flow of daily life attachment insecurity fluctuates, whether elevated stress precedes the occurrence of attachment insecurity, and whether elevated attachment insecurity precedes the occurrence of paranoia. Twenty clinical participants with a psychosis-spectrum diagnosis and twenty controls were studied over six consecutive days using the experience sampling method (ESM). The findings revealed that fluctuations in attachment insecurity were significantly higher in the clinical group, that elevated stress predicted a subsequent increase in attachment insecurity, and that elevated attachment insecurity predicted a subsequent increase in paranoia; this effect was not observed in auditory hallucinations once co-occurring symptoms were controlled for. Finally, although previous ESM studies have shown that low self-esteem precedes the occurrence of paranoia, attachment insecurity continued to predict paranoia even when self-esteem was controlled for. The findings suggest that attachment security may be associated with a lower risk of paranoia, and that psychological interventions should address attachment beliefs and work towards establishing a sense of attachment security. Copyright © 2016. Published by Elsevier Ireland Ltd.

  14. Study of β-NMR for Liquid Biological Samples

    CERN Document Server

    Beattie, Caitlin

    2017-01-01

    β-NMR is an exotic form of NMR spectroscopy that allows for the characterization of matter based on the anisotropic β-decay of radioactive probe nuclei. This has been shown to be an effective spectroscopic technique for many different compounds, but its use for liquid biological samples is relatively unexplored. The work at the VITO line of ISOLDE seeks to employ this technique to study such samples. Currently, preparations are being made for an experiment to characterize DNA G-quadruplexes and their interactions with stabilizing cations. More specifically, the work in which I engaged as a summer student focused on the experiment’s liquid handling system and the stability of the relevant biological samples under vacuum.

  15. Transcriptome classification reveals molecular subtypes in psoriasis

    Directory of Open Access Journals (Sweden)

    Ainali Chrysanthi

    2012-09-01

    Full Text Available Abstract Background Psoriasis is an immune-mediated disease characterised by chronically elevated pro-inflammatory cytokine levels, leading to aberrant keratinocyte proliferation and differentiation. Although certain clinical phenotypes, such as plaque psoriasis, are well defined, it is currently unclear whether there are molecular subtypes that might impact on prognosis or treatment outcomes. Results We present a pipeline for patient stratification through a comprehensive analysis of gene expression in paired lesional and non-lesional psoriatic tissue samples, compared with controls, to establish differences in RNA expression patterns across all tissue types. Ensembles of decision tree predictors were employed to cluster psoriatic samples on the basis of gene expression patterns and reveal gene expression signatures that best discriminate molecular disease subtypes. This multi-stage procedure was applied to several published psoriasis studies and a comparison of gene expression patterns across datasets was performed. Conclusion Overall, classification of psoriasis gene expression patterns revealed distinct molecular sub-groups within the clinical phenotype of plaque psoriasis. Enrichment for TGFb and ErbB signaling pathways, noted in one of the two psoriasis subgroups, suggested that this group may be more amenable to therapies targeting these pathways. Our study highlights the potential biological relevance of using ensemble decision tree predictors to determine molecular disease subtypes, in what may initially appear to be a homogenous clinical group. The R code used in this paper is available upon request.

  16. Acoustically levitated droplets: a contactless sampling method for fluorescence studies.

    Science.gov (United States)

    Leiterer, Jork; Grabolle, Markus; Rurack, Knut; Resch-Genger, Ute; Ziegler, Jan; Nann, Thomas; Panne, Ulrich

    2008-01-01

    Acoustic levitation is used as a new tool to study concentration-dependent processes in fluorescence spectroscopy. With this technique, small amounts of liquid and solid samples can be measured without the need for sample supports or containers, which often limits signal acquisition and can even alter sample properties due to interactions with the support material. We demonstrate that, because of the small sample volume, fluorescence measurements at high concentrations of an organic dye are possible without the limitation of inner-filter effects, which hamper such experiments in conventional, cuvette-based measurements. Furthermore, we show that acoustic levitation of liquid samples provides an experimentally simple way to study distance-dependent fluorescence modulations in semiconductor nanocrystals. The evaporation of the solvent during levitation leads to a continuous increase of solute concentration and can easily be monitored by laser-induced fluorescence.

  17. Museum samples reveal rapid evolution by wild honey bees exposed to a novel parasite.

    Science.gov (United States)

    Mikheyev, Alexander S; Tin, Mandy M Y; Arora, Jatin; Seeley, Thomas D

    2015-08-06

    Understanding genetic changes caused by novel pathogens and parasites can reveal mechanisms of adaptation and genetic robustness. Using whole-genome sequencing of museum and modern specimens, we describe the genomic changes in a wild population of honey bees in North America following the introduction of the ectoparasitic mite, Varroa destructor. Even though colony density in the study population is the same today as in the past, a major loss of haplotypic diversity occurred, indicative of a drastic mitochondrial bottleneck, caused by massive colony mortality. In contrast, nuclear genetic diversity did not change, though hundreds of genes show signs of selection. The genetic diversity within each bee colony, particularly as a consequence of polyandry by queens, may enable preservation of genetic diversity even during population bottlenecks. These findings suggest that genetically diverse honey bee populations can recover from introduced diseases by evolving rapid tolerance, while maintaining much of the standing genetic variation.

  18. Evaluation of common methods for sampling invertebrate pollinator assemblages: net sampling out-perform pan traps.

    Science.gov (United States)

    Popic, Tony J; Davila, Yvonne C; Wardle, Glenda M

    2013-01-01

    Methods for sampling ecological assemblages strive to be efficient, repeatable, and representative. Unknowingly, common methods may be limited in terms of revealing species function and so of less value for comparative studies. The global decline in pollination services has stimulated surveys of flower-visiting invertebrates, using pan traps and net sampling. We explore the relative merits of these two methods in terms of species discovery, quantifying abundance, function, and composition, and responses of species to changing floral resources. Using a spatially-nested design we sampled across a 5000 km(2) area of arid grasslands, including 432 hours of net sampling and 1296 pan trap-days, between June 2010 and July 2011. Net sampling yielded 22% more species and 30% higher abundance than pan traps, and better reflected the spatio-temporal variation of floral resources. Species composition differed significantly between methods; from 436 total species, 25% were sampled by both methods, 50% only by nets, and the remaining 25% only by pans. Apart from being less comprehensive, if pan traps do not sample flower-visitors, the link to pollination is questionable. By contrast, net sampling functionally linked species to pollination through behavioural observations of flower-visitation interaction frequency. Netted specimens are also necessary for evidence of pollen transport. Benefits of net-based sampling outweighed minor differences in overall sampling effort. As pan traps and net sampling methods are not equivalent for sampling invertebrate-flower interactions, we recommend net sampling of invertebrate pollinator assemblages, especially if datasets are intended to document declines in pollination and guide measures to retain this important ecosystem service.

  19. Quantitative proteomic study of Aspergillus Fumigatus secretome revealed deamidation of secretory enzymes.

    Science.gov (United States)

    Adav, Sunil S; Ravindran, Anita; Sze, Siu Kwan

    2015-04-24

    Aspergillus sp. plays an essential role in lignocellulosic biomass recycling and is also exploited as cell factories for the production of industrial enzymes. This study profiled the secretome of Aspergillus fumigatus when grown with cellulose, xylan and starch by high throughput quantitative proteomics using isobaric tags for relative and absolute quantification (iTRAQ). Post translational modifications (PTMs) of proteins play a critical role in protein functions. However, our understanding of the PTMs in secretory proteins is limited. Here, we present the identification of PTMs such as deamidation of secreted proteins of A. fumigatus. This study quantified diverse groups of extracellular secreted enzymes and their functional classification revealed cellulases and glycoside hydrolases (32.9%), amylases (0.9%), hemicellulases (16.2%), lignin degrading enzymes (8.1%), peptidases and proteases (11.7%), chitinases, lipases and phosphatases (7.6%), and proteins with unknown function (22.5%). The comparison of quantitative iTRAQ results revealed that cellulose and xylan stimulates expression of specific cellulases and hemicellulases, and their abundance level as a function of substrate. In-depth data analysis revealed deamidation as a major PTM of key cellulose hydrolyzing enzymes like endoglucanases, cellobiohydrolases and glucosidases. Hemicellulose degrading endo-1,4-beta-xylanase, monosidases, xylosidases, lignin degrading laccase, isoamyl alcohol oxidase and oxidoreductases were also found to be deamidated. The filamentous fungi play an essential role in lignocellulosic biomass recycling and fungal strains belonging to Aspergillus were also exploited as cell factories for the production of organic acids, pharmaceuticals, and industrially important enzymes. In this study, extracellular proteins secreted by thermophilic A. fumigatus when grown with cellulose, xylan and starch were profiled using isobaric tags for relative and absolute quantification (iTRAQ) by

  20. Audit sampling: A qualitative study on the role of statistical and non-statistical sampling approaches on audit practices in Sweden

    OpenAIRE

    Ayam, Rufus Tekoh

    2011-01-01

    PURPOSE: The two approaches to audit sampling; statistical and nonstatistical have been examined in this study. The overall purpose of the study is to explore the current extent at which statistical and nonstatistical sampling approaches are utilized by independent auditors during auditing practices. Moreover, the study also seeks to achieve two additional purposes; the first is to find out whether auditors utilize different sampling techniques when auditing SME´s (Small and Medium-Sized Ente...

  1. Assessing the precision of a time-sampling-based study among GPs: balancing sample size and measurement frequency.

    Science.gov (United States)

    van Hassel, Daniël; van der Velden, Lud; de Bakker, Dinny; van der Hoek, Lucas; Batenburg, Ronald

    2017-12-04

    Our research is based on a technique for time sampling, an innovative method for measuring the working hours of Dutch general practitioners (GPs), which was deployed in an earlier study. In this study, 1051 GPs were questioned about their activities in real time by sending them one SMS text message every 3 h during 1 week. The required sample size for this study is important for health workforce planners to know if they want to apply this method to target groups who are hard to reach or if fewer resources are available. In this time-sampling method, however, standard power analyses is not sufficient for calculating the required sample size as this accounts only for sample fluctuation and not for the fluctuation of measurements taken from every participant. We investigated the impact of the number of participants and frequency of measurements per participant upon the confidence intervals (CIs) for the hours worked per week. Statistical analyses of the time-use data we obtained from GPs were performed. Ninety-five percent CIs were calculated, using equations and simulation techniques, for various different numbers of GPs included in the dataset and for various frequencies of measurements per participant. Our results showed that the one-tailed CI, including sample and measurement fluctuation, decreased from 21 until 3 h between one and 50 GPs. As a result of the formulas to calculate CIs, the increase of the precision continued and was lower with the same additional number of GPs. Likewise, the analyses showed how the number of participants required decreased if more measurements per participant were taken. For example, one measurement per 3-h time slot during the week requires 300 GPs to achieve a CI of 1 h, while one measurement per hour requires 100 GPs to obtain the same result. The sample size needed for time-use research based on a time-sampling technique depends on the design and aim of the study. In this paper, we showed how the precision of the

  2. Aragonite-Calcite Inversion During Biogenic Carbonate Sampling: Considerations for Interpreting Isotopic Measurements in Paleoclimate Studies

    Science.gov (United States)

    Waite, A. J.; Swart, P. K.

    2011-12-01

    As aragonite is the metastable polymorph of calcium carbonate, it lends itself to monotropic inversion to the more stable polymorph, calcite. This inversion is possible through an increase in the temperature and pressure conditions to which the sample is exposed and, although first noted nearly a century ago, has been primarily discussed in the context of sample roasting prior to analyses in paleoclimatological studies. Over the last several decades, however, researchers have found evidence to suggest that the friction associated with the sampling of biogenic carbonates via milling/drilling also induces inversion. Furthermore, this inversion may be associated with a shift in measured oxygen isotopic values and ultimately have significant implications for the interpretation of paleoclimatic reconstructions. Despite this, the isotopic heterogeneity of biogenic aragonite skeletons makes the effects of inversion challenging to test and the subject remains underrepresented in the literature. Here we present a first order study into the effects of milling on both the mineralogy and isotopic compositions measured in sclerosponges, corals, and molluscs. X-Ray diffraction analysis of samples hand ground with a mortar and pestle reveal 100% aragonitic skeletons. Conversely, samples milled with a computerized micromill show measurable inversion to calcite. On average, percent inversion of aragonite to calcite for individual specimens was 15% for sclerosponges, 16% for corals, and 9% for molluscs. Isotopic data from these specimens show that the higher the percentage of aragonite inverted to calcite, the more depleted the measured oxygen isotopic values. In the largest of the datasets (sclerosponges), it is evident that the range of oxygen isotope values from milled samples (-0.02 to +0.84%) exceeds the range in values for those samples which were hand ground and showed no inversion (+0.53 to +0.90%). This, coupled with the strong correlation between the two variables

  3. Generalizability of causal inference in observational studies under retrospective convenience sampling.

    Science.gov (United States)

    Hu, Zonghui; Qin, Jing

    2018-05-20

    Many observational studies adopt what we call retrospective convenience sampling (RCS). With the sample size in each arm prespecified, RCS randomly selects subjects from the treatment-inclined subpopulation into the treatment arm and those from the control-inclined into the control arm. Samples in each arm are representative of the respective subpopulation, but the proportion of the 2 subpopulations is usually not preserved in the sample data. We show in this work that, under RCS, existing causal effect estimators actually estimate the treatment effect over the sample population instead of the underlying study population. We investigate how to correct existing methods for consistent estimation of the treatment effect over the underlying population. Although RCS is adopted in medical studies for ethical and cost-effective purposes, it also has a big advantage for statistical inference: When the tendency to receive treatment is low in a study population, treatment effect estimators under RCS, with proper correction, are more efficient than their parallels under random sampling. These properties are investigated both theoretically and through numerical demonstration. Published 2018. This article is a U.S. Government work and is in the public domain in the USA.

  4. Sampling strategies for tropical forest nutrient cycling studies: a case study in São Paulo, Brazil

    Directory of Open Access Journals (Sweden)

    G. Sparovek

    1997-12-01

    Full Text Available The precise sampling of soil, biological or micro climatic attributes in tropical forests, which are characterized by a high diversity of species and complex spatial variability, is a difficult task. We found few basic studies to guide sampling procedures. The objective of this study was to define a sampling strategy and data analysis for some parameters frequently used in nutrient cycling studies, i. e., litter amount, total nutrient amounts in litter and its composition (Ca, Mg, Κ, Ν and P, and soil attributes at three depths (organic matter, Ρ content, cation exchange capacity and base saturation. A natural remnant forest in the West of São Paulo State (Brazil was selected as study area and samples were collected in July, 1989. The total amount of litter and its total nutrient amounts had a high spatial independent variance. Conversely, the variance of litter composition was lower and the spatial dependency was peculiar to each nutrient. The sampling strategy for the estimation of litter amounts and the amount of nutrient in litter should be different than the sampling strategy for nutrient composition. For the estimation of litter amounts and the amount of nutrients in litter (related to quantity a large number of randomly distributed determinations are needed. Otherwise, for the estimation of litter nutrient composition (related to quality a smaller amount of spatially located samples should be analyzed. The determination of sampling for soil attributes differed according to the depth. Overall, surface samples (0-5 cm showed high short distance spatial dependent variance, whereas, subsurface samples exhibited spatial dependency in longer distances. Short transects with sampling interval of 5-10 m are recommended for surface sampling. Subsurface samples must also be spatially located, but with transects or grids with longer distances between sampling points over the entire area. Composite soil samples would not provide a complete

  5. Museum samples reveal rapid evolution by wild honey bees exposed to a novel parasite

    Science.gov (United States)

    Mikheyev, Alexander S.; Tin, Mandy M. Y.; Arora, Jatin; Seeley, Thomas D.

    2015-01-01

    Understanding genetic changes caused by novel pathogens and parasites can reveal mechanisms of adaptation and genetic robustness. Using whole-genome sequencing of museum and modern specimens, we describe the genomic changes in a wild population of honey bees in North America following the introduction of the ectoparasitic mite, Varroa destructor. Even though colony density in the study population is the same today as in the past, a major loss of haplotypic diversity occurred, indicative of a drastic mitochondrial bottleneck, caused by massive colony mortality. In contrast, nuclear genetic diversity did not change, though hundreds of genes show signs of selection. The genetic diversity within each bee colony, particularly as a consequence of polyandry by queens, may enable preservation of genetic diversity even during population bottlenecks. These findings suggest that genetically diverse honey bee populations can recover from introduced diseases by evolving rapid tolerance, while maintaining much of the standing genetic variation. PMID:26246313

  6. [A comparison of convenience sampling and purposive sampling].

    Science.gov (United States)

    Suen, Lee-Jen Wu; Huang, Hui-Man; Lee, Hao-Hsien

    2014-06-01

    Convenience sampling and purposive sampling are two different sampling methods. This article first explains sampling terms such as target population, accessible population, simple random sampling, intended sample, actual sample, and statistical power analysis. These terms are then used to explain the difference between "convenience sampling" and purposive sampling." Convenience sampling is a non-probabilistic sampling technique applicable to qualitative or quantitative studies, although it is most frequently used in quantitative studies. In convenience samples, subjects more readily accessible to the researcher are more likely to be included. Thus, in quantitative studies, opportunity to participate is not equal for all qualified individuals in the target population and study results are not necessarily generalizable to this population. As in all quantitative studies, increasing the sample size increases the statistical power of the convenience sample. In contrast, purposive sampling is typically used in qualitative studies. Researchers who use this technique carefully select subjects based on study purpose with the expectation that each participant will provide unique and rich information of value to the study. As a result, members of the accessible population are not interchangeable and sample size is determined by data saturation not by statistical power analysis.

  7. Experimental study of glass sampling devices

    International Nuclear Information System (INIS)

    Jouan, A.; Moncouyoux, J.P.; Meyere, A.

    1992-01-01

    Two high-level liquid waste containment glass sampling systems have been designed and built. The first device fits entirely inside a standard glass storage canister, and may thus be used in facilities not initially designed for this function. It has been tested successfully in the nonradioactive prototype unit at Marcoule. The work primarily covered the design and construction of an articulated arm supporting the sampling vessel, and the mechanisms necessary for filling the vessel and recovering the sample. System actuation and operation are fully automatic, and the resulting sample is representative of the glass melt. Implementation of the device is delicate however, and its reliability is estimated at about 75%. A second device was designed specifically for new vitrification facilities. It is installed directly on the glass melting furnace, and meets process operating and quality control requirements. Tests conducted at the Marcoule prototype vitrification facility demonstrated the feasibility of the system. Special attention was given to the sampling vessel transfer mechanisms, with two filling and controlled sample cooling options

  8. Direct sampling during multiple sediment density flows reveals dynamic sediment transport and depositional environment in Monterey submarine canyon

    Science.gov (United States)

    Maier, K. L.; Gales, J. A.; Paull, C. K.; Gwiazda, R.; Rosenberger, K. J.; McGann, M.; Lundsten, E. M.; Anderson, K.; Talling, P.; Xu, J.; Parsons, D. R.; Barry, J.; Simmons, S.; Clare, M. A.; Carvajal, C.; Wolfson-Schwehr, M.; Sumner, E.; Cartigny, M.

    2017-12-01

    Sediment density flows were directly sampled with a coupled sediment trap-ADCP-instrument mooring array to evaluate the character and frequency of turbidity current events through Monterey Canyon, offshore California. This novel experiment aimed to provide links between globally significant sediment density flow processes and their resulting deposits. Eight to ten Anderson sediment traps were repeatedly deployed at 10 to 300 meters above the seafloor on six moorings anchored at 290 to 1850 meters water depth in the Monterey Canyon axial channel during 6-month deployments (October 2015 - April 2017). Anderson sediment traps include a funnel and intervalometer (discs released at set time intervals) above a meter-long tube, which preserves fine-scale stratigraphy and chronology. Photographs, multi-sensor logs, CT scans, and grain size analyses reveal layers from multiple sediment density flow events that carried sediment ranging from fine sand to granules. More sediment accumulation from sediment density flows, and from between flows, occurred in the upper canyon ( 300 - 800 m water depth) compared to the lower canyon ( 1300 - 1850 m water depth). Sediment accumulated in the traps during sediment density flows is sandy and becomes finer down-canyon. In the lower canyon where sediment directly sampled from density flows are clearly distinguished within the trap tubes, sands have sharp basal contacts, normal grading, and muddy tops that exhibit late-stage pulses. In at least two of the sediment density flows, the simultaneous low velocity and high backscatter measured by the ADCPs suggest that the trap only captured the collapsing end of a sediment density flow event. In the upper canyon, accumulation between sediment density flow events is twice as fast compared to the lower canyon; it is characterized by sub-cm-scale layers in muddy sediment that appear to have accumulated with daily to sub-daily frequency, likely related to known internal tidal dynamics also measured

  9. Sample Size Calculations for Population Size Estimation Studies Using Multiplier Methods With Respondent-Driven Sampling Surveys.

    Science.gov (United States)

    Fearon, Elizabeth; Chabata, Sungai T; Thompson, Jennifer A; Cowan, Frances M; Hargreaves, James R

    2017-09-14

    While guidance exists for obtaining population size estimates using multiplier methods with respondent-driven sampling surveys, we lack specific guidance for making sample size decisions. To guide the design of multiplier method population size estimation studies using respondent-driven sampling surveys to reduce the random error around the estimate obtained. The population size estimate is obtained by dividing the number of individuals receiving a service or the number of unique objects distributed (M) by the proportion of individuals in a representative survey who report receipt of the service or object (P). We have developed an approach to sample size calculation, interpreting methods to estimate the variance around estimates obtained using multiplier methods in conjunction with research into design effects and respondent-driven sampling. We describe an application to estimate the number of female sex workers in Harare, Zimbabwe. There is high variance in estimates. Random error around the size estimate reflects uncertainty from M and P, particularly when the estimate of P in the respondent-driven sampling survey is low. As expected, sample size requirements are higher when the design effect of the survey is assumed to be greater. We suggest a method for investigating the effects of sample size on the precision of a population size estimate obtained using multipler methods and respondent-driven sampling. Uncertainty in the size estimate is high, particularly when P is small, so balancing against other potential sources of bias, we advise researchers to consider longer service attendance reference periods and to distribute more unique objects, which is likely to result in a higher estimate of P in the respondent-driven sampling survey. ©Elizabeth Fearon, Sungai T Chabata, Jennifer A Thompson, Frances M Cowan, James R Hargreaves. Originally published in JMIR Public Health and Surveillance (http://publichealth.jmir.org), 14.09.2017.

  10. A Next-Generation Sequencing Data Analysis Pipeline for Detecting Unknown Pathogens from Mixed Clinical Samples and Revealing Their Genetic Diversity.

    Directory of Open Access Journals (Sweden)

    Yu-Nong Gong

    Full Text Available Forty-two cytopathic effect (CPE-positive isolates were collected from 2008 to 2012. All isolates could not be identified for known viral pathogens by routine diagnostic assays. They were pooled into 8 groups of 5-6 isolates to reduce the sequencing cost. Next-generation sequencing (NGS was conducted for each group of mixed samples, and the proposed data analysis pipeline was used to identify viral pathogens in these mixed samples. Polymerase chain reaction (PCR or enzyme-linked immunosorbent assay (ELISA was individually conducted for each of these 42 isolates depending on the predicted viral types in each group. Two isolates remained unknown after these tests. Moreover, iteration mapping was implemented for each of these 2 isolates, and predicted human parechovirus (HPeV in both. In summary, our NGS pipeline detected the following viruses among the 42 isolates: 29 human rhinoviruses (HRVs, 10 HPeVs, 1 human adenovirus (HAdV, 1 echovirus and 1 rotavirus. We then focused on the 10 identified Taiwanese HPeVs because of their reported clinical significance over HRVs. Their genomes were assembled and their genetic diversity was explored. One novel 6-bp deletion was found in one HPeV-1 virus. In terms of nucleotide heterogeneity, 64 genetic variants were detected from these HPeVs using the mapped NGS reads. Most importantly, a recombination event was found between our HPeV-3 and a known HPeV-4 strain in the database. Similar event was detected in the other HPeV-3 strains in the same clade of the phylogenetic tree. These findings demonstrated that the proposed NGS data analysis pipeline identified unknown viruses from the mixed clinical samples, revealed their genetic identity and variants, and characterized their genetic features in terms of viral evolution.

  11. Sample Size and Saturation in PhD Studies Using Qualitative Interviews

    Directory of Open Access Journals (Sweden)

    Mark Mason

    2010-08-01

    Full Text Available A number of issues can affect sample size in qualitative research; however, the guiding principle should be the concept of saturation. This has been explored in detail by a number of authors but is still hotly debated, and some say little understood. A sample of PhD studies using qualitative approaches, and qualitative interviews as the method of data collection was taken from theses.com and contents analysed for their sample sizes. Five hundred and sixty studies were identified that fitted the inclusion criteria. Results showed that the mean sample size was 31; however, the distribution was non-random, with a statistically significant proportion of studies, presenting sample sizes that were multiples of ten. These results are discussed in relation to saturation. They suggest a pre-meditated approach that is not wholly congruent with the principles of qualitative research. URN: urn:nbn:de:0114-fqs100387

  12. Network Sampling with Memory: A proposal for more efficient sampling from social networks

    Science.gov (United States)

    Mouw, Ted; Verdery, Ashton M.

    2013-01-01

    Techniques for sampling from networks have grown into an important area of research across several fields. For sociologists, the possibility of sampling from a network is appealing for two reasons: (1) A network sample can yield substantively interesting data about network structures and social interactions, and (2) it is useful in situations where study populations are difficult or impossible to survey with traditional sampling approaches because of the lack of a sampling frame. Despite its appeal, methodological concerns about the precision and accuracy of network-based sampling methods remain. In particular, recent research has shown that sampling from a network using a random walk based approach such as Respondent Driven Sampling (RDS) can result in high design effects (DE)—the ratio of the sampling variance to the sampling variance of simple random sampling (SRS). A high design effect means that more cases must be collected to achieve the same level of precision as SRS. In this paper we propose an alternative strategy, Network Sampling with Memory (NSM), which collects network data from respondents in order to reduce design effects and, correspondingly, the number of interviews needed to achieve a given level of statistical power. NSM combines a “List” mode, where all individuals on the revealed network list are sampled with the same cumulative probability, with a “Search” mode, which gives priority to bridge nodes connecting the current sample to unexplored parts of the network. We test the relative efficiency of NSM compared to RDS and SRS on 162 school and university networks from Add Health and Facebook that range in size from 110 to 16,278 nodes. The results show that the average design effect for NSM on these 162 networks is 1.16, which is very close to the efficiency of a simple random sample (DE=1), and 98.5% lower than the average DE we observed for RDS. PMID:24159246

  13. Linking community tolerance and structure with low metallic contamination: a field study on 13 biofilms sampled across the Seine river basin.

    Science.gov (United States)

    Fechner, Lise C; Gourlay-Francé, Catherine; Tusseau-Vuillemin, Marie-Hélène

    2014-03-15

    It is difficult to assess the biological consequences of diffuse water contamination by micropollutants which are present in rivers at low, even sublethal levels. River biofilms, which respond quickly to changes of environmental parameters, are good candidates to acquire knowledge on the response of aquatic organisms to diffuse chemical contamination in the field. The study was designed as an attempt to link biofilm metal tolerance and metallic contamination in a field survey covering 13 different sampling sites in the Seine river basin (north of France) with low contamination levels. Cd and Zn tolerance of heterotrophic communities was assessed using a short-term toxicity test based on β-glucosidase activity. Metal tolerance levels varied between sites but there was no obvious correlation between tolerance and corresponding water contamination levels for Cd and Zn. Indeed, metallic contamination at the sampling sites remained subtle when compared to water quality standards (only two sampling sites had either Zn or both Cu and Zn concentrations exceeding the Environmental Quality Standards set by the EU Water Framework Directive). Yet, multivariate analysis of the data using Partial Least Squares Regression revealed that both metallic and environmental parameters were important variables explaining the variability of metal tolerance levels. Automated Ribosomal Intergenic Spacer Analysis (ARISA) was also performed on both bacterial and eukaryotic biofilm communities from the 13 sampling sites. Multivariate analysis of ARISA fingerprints revealed that biofilms with similar tolerance levels have similar ARISA profiles. Those results confirm that river biofilms are potential indicators of low, diffuse contamination levels of aquatic systems. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Minimally-invasive Sampling of Interleukin-1α and Interleukin-1 Receptor Antagonist from the Skin: A Systematic Review of In vivo Studies in Humans.

    Science.gov (United States)

    Falcone, Denise; Spee, Pieter; van de Kerkhof, Peter C M; van Erp, Piet E J

    2017-10-02

    Interleukin-1α (IL-1α) and its receptor antagonist IL-1RA play a pivotal role in skin homeostasis and disease. Although the use of biopsies to sample these cytokines from human skin is widely employed in dermatological practice, knowledge about less invasive, in vivo sampling methods is scarce. The aim of this study was to provide an overview of such methods by systematically reviewing studies in Medline, EMBASE, Web of Science and Cochrane Library using combinations of the terms "IL-1α", IL-1RA", "skin", "human", including all possible synonyms. Quality was assessed using the STrengthening the Reporting of OBservational studies in Epidemiology (STROBE) checklist. The search, performed on 14 October 2016, revealed 10 different sampling methods, with varying degrees of invasiveness and wide application spectrum, including assessment of both normal and diseased skin, from several body sites. The possibility to sample quantifiable amounts of cytokines from human skin with no or minimal discomfort holds promise for linking clinical outcomes to molecular profiles of skin inflammation.

  15. Evaluation of common methods for sampling invertebrate pollinator assemblages: net sampling out-perform pan traps.

    Directory of Open Access Journals (Sweden)

    Tony J Popic

    Full Text Available Methods for sampling ecological assemblages strive to be efficient, repeatable, and representative. Unknowingly, common methods may be limited in terms of revealing species function and so of less value for comparative studies. The global decline in pollination services has stimulated surveys of flower-visiting invertebrates, using pan traps and net sampling. We explore the relative merits of these two methods in terms of species discovery, quantifying abundance, function, and composition, and responses of species to changing floral resources. Using a spatially-nested design we sampled across a 5000 km(2 area of arid grasslands, including 432 hours of net sampling and 1296 pan trap-days, between June 2010 and July 2011. Net sampling yielded 22% more species and 30% higher abundance than pan traps, and better reflected the spatio-temporal variation of floral resources. Species composition differed significantly between methods; from 436 total species, 25% were sampled by both methods, 50% only by nets, and the remaining 25% only by pans. Apart from being less comprehensive, if pan traps do not sample flower-visitors, the link to pollination is questionable. By contrast, net sampling functionally linked species to pollination through behavioural observations of flower-visitation interaction frequency. Netted specimens are also necessary for evidence of pollen transport. Benefits of net-based sampling outweighed minor differences in overall sampling effort. As pan traps and net sampling methods are not equivalent for sampling invertebrate-flower interactions, we recommend net sampling of invertebrate pollinator assemblages, especially if datasets are intended to document declines in pollination and guide measures to retain this important ecosystem service.

  16. Mobile Variable Depth Sampling System Design Study

    International Nuclear Information System (INIS)

    BOGER, R.M.

    2000-01-01

    A design study is presented for a mobile, variable depth sampling system (MVDSS) that will support the treatment and immobilization of Hanford LAW and HLW. The sampler can be deployed in a 4-inch tank riser and has a design that is based on requirements identified in the Level 2 Specification (latest revision). The waste feed sequence for the MVDSS is based on Phase 1, Case 3S6 waste feed sequence. Technical information is also presented that supports the design study

  17. Mobile Variable Depth Sampling System Design Study

    Energy Technology Data Exchange (ETDEWEB)

    BOGER, R.M.

    2000-08-25

    A design study is presented for a mobile, variable depth sampling system (MVDSS) that will support the treatment and immobilization of Hanford LAW and HLW. The sampler can be deployed in a 4-inch tank riser and has a design that is based on requirements identified in the Level 2 Specification (latest revision). The waste feed sequence for the MVDSS is based on Phase 1, Case 3S6 waste feed sequence. Technical information is also presented that supports the design study.

  18. The rumen microbial metaproteome as revealed by SDS-PAGE.

    Science.gov (United States)

    Snelling, Timothy J; Wallace, R John

    2017-01-07

    Ruminal digestion is carried out by large numbers of bacteria, archaea, protozoa and fungi. Understanding the microbiota is important because ruminal fermentation dictates the efficiency of feed utilisation by the animal and is also responsible for major emissions of the greenhouse gas, methane. Recent metagenomic and metatranscriptomic studies have helped to elucidate many features of the composition and activity of the microbiota. The metaproteome provides complementary information to these other -omics technologies. The aim of this study was to explore the metaproteome of bovine and ovine ruminal digesta using 2D SDS-PAGE. Digesta samples were taken via ruminal fistulae and by gastric intubation, or at slaughter, and stored in glycerol at -80 °C. A protein extraction protocol was developed to maximise yield and representativeness of the protein content. The proteome of ruminal digesta taken from dairy cows fed a high concentrate diet was dominated by a few very highly expressed proteins, which were identified by LC-MS/MS to be structural proteins, such as actin and α- and β-tubulins, derived from ciliate protozoa. Removal of protozoa from digesta before extraction of proteins revealed the prokaryotic metaproteome, which was dominated by enzymes involved in glycolysis, such as glyceraldehyde-3-phosphate dehydrogenase, phosphoenolpyruvate carboxykinase, phosphoglycerate kinase and triosephosphate isomerase. The enzymes were predominantly from the Firmicutes and Bacteroidetes phyla. Enzymes from methanogenic archaea were also abundant, consistent with the importance of methane formation in the rumen. Gels from samples from dairy cows fed a high proportion of grass silage were consistently obscured by co-staining of humic compounds. Samples from beef cattle and fattening lambs receiving a predominantly concentrate diet produced clearer gels, but the pattern of spots was inconsistent between samples, making comparisons difficult. This work demonstrated for the

  19. Optimized cryo-focused ion beam sample preparation aimed at in situ structural studies of membrane proteins.

    Science.gov (United States)

    Schaffer, Miroslava; Mahamid, Julia; Engel, Benjamin D; Laugks, Tim; Baumeister, Wolfgang; Plitzko, Jürgen M

    2017-02-01

    While cryo-electron tomography (cryo-ET) can reveal biological structures in their native state within the cellular environment, it requires the production of high-quality frozen-hydrated sections that are thinner than 300nm. Sample requirements are even more stringent for the visualization of membrane-bound protein complexes within dense cellular regions. Focused ion beam (FIB) sample preparation for transmission electron microscopy (TEM) is a well-established technique in material science, but there are only few examples of biological samples exhibiting sufficient quality for high-resolution in situ investigation by cryo-ET. In this work, we present a comprehensive description of a cryo-sample preparation workflow incorporating additional conductive-coating procedures. These coating steps eliminate the adverse effects of sample charging on imaging with the Volta phase plate, allowing data acquisition with improved contrast. We discuss optimized FIB milling strategies adapted from material science and each critical step required to produce homogeneously thin, non-charging FIB lamellas that make large areas of unperturbed HeLa and Chlamydomonas cells accessible for cryo-ET at molecular resolution. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Evolution of concentration-discharge relations revealed by high frequency diurnal sampling of stream water during spring snowmelt

    Science.gov (United States)

    Olshansky, Y.; White, A. M.; Thompson, M.; Moravec, B. G.; McIntosh, J. C.; Chorover, J.

    2017-12-01

    Concentration discharge (C-Q) relations contain potentially important information on critical zone (CZ) processes including: weathering reactions, water flow paths and nutrient export. To examine the C-Q relations in a small (3.3 km2) headwater catchment - La Jara Creek located in the Jemez River Basin Critical Zone Observatory, daily, diurnal stream water samples were collected during spring snow melt 2017, from two flumes located in outlets of the La Jara Creek and a high elevation zero order basin within this catchment. Previous studies from this site (McIntosh et al., 2017) suggested that high frequency sampling was needed to improve our interpretation of C-Q relations. The dense sampling covered two ascending and two descending limbs of the snowmelt hydrograph, from March 1 to May 15, 2017. While Na showed inverse correlation (dilution) with discharge, most other solutes (K, Mg, Fe, Al, dissolved organic carbon) exhibited positive (concentration) or chemostatic trends (Ca, Mn, Si, dissolved inorganic carbon and dissolved nitrogen). Hysteresis in the C-Q relation was most pronounced for bio-cycled cations (K, Mg) and for Fe, which exhibited concentration during the first ascending limb followed by a chemostatic trend. A pulsed increase in Si concentration immediately after the first ascending limb in both flumes suggests mixing of deep groundwater with surface water. A continual increase in Ge/Si concentrations followed by a rapid decrease after the second rising limb may suggest a fast transition between soil water to ground water dominating the stream flow. Fourier transform infrared spectroscopy of selected samples across the hydrograph demonstrated pronounced changes in dissolved organic matter molecular composition with the advancement of the spring snow melt. X-ray micro-spectroscopy of colloidal material isolated from the collected water samples indicated a significant role for organic matter in the transport of inorganic colloids. Analyses of high

  1. Experimental Study of Impregnation Birch and Aspen Samples

    Directory of Open Access Journals (Sweden)

    Igor Vladislavovich Grigorev

    2014-10-01

    Full Text Available An experimental study of wood impregnation was implemented by applying centrifugal methods. The impregnants were a 10% aqueous solution of potassium chloride and a 2% aqueous solution of borax. Birch (Betula pendula and aspen (Populus tremula wood samples in different moisture content were tested. The impregnation time in the centrifugal device were 30 seconds repeated 21 times, and the samples were measured after every 30 seconds. The experimental results were fitted to a nonlinear filtration law, which indicated that the centrifugal wood impregnation was dependent on wood species, wood moisture, rotational speed, and radius. Determination of rotational speed and centrifuge radius for impregnating aspen and birch at varying lengths and humidity under conditions of the nonlinear impregnant filtration law can be done using the example charts that were developed and presented in this study.

  2. Analyses of archaeological pottery samples using X-ray fluorescence technique for provenance study

    International Nuclear Information System (INIS)

    Tamilarasu, S.; Swain, K.K.; Singhal, R.K; Reddy, A.V.R.; Acharya, R.; Velraj, G.

    2015-01-01

    Archaeological artifacts reveal information on past human activities, artifact preparation technology, art and possible trade. Ceramics are the most stable and abundant material in archaeological context. Pottery is the most abundant tracers in all archaeological excavations. Compared to major elements, elements present at trace concentrations levels are source specific and they maintain same concentration levels in source clay as well as finished products e.g., fired clay potteries. As it is difficult to find out exact source or origin, provenance study is carried out first to establish whether objects under study are from the same or different sources/origin. Various analytical techniques like instrumental neutron activation analysis (INAA), Ion beam analysis (IBA) and X-ray fluorescence (XRF) have been used for obtaining elemental concentrations in archaeological potteries. Portable X-ray fluorescence (pXRF) spectrometry provides a non-destructive means for elemental characterization of a wide range of archaeological materials. Ten archaeological pottery samples were collected from Kottapuram, Kerala under the supervision of archaeological survey of India. Portable X-ray fluorescence (pXRF) spectrometry using a handheld Olympus Innov-X Delta XRF device, ACD BARC, has been used for chemical characterization of the pottery samples. The instrument is equipped with the Delta Rhodium (Rh) anode X-Ray tube and uses a Silicon Drift Detector (resolution <200 eV at 5.95 keV Mn Kα X-ray). NIST 2781 SRM was analyzed for quality control purpose. Ten elements namely Fe, Ti, Mn, Co, Cu, Zn, Pb, Zr, Mo and Se were chosen for cluster analysis and their concentration values were utilized for multivariate statistical analysis using WinSTAT 9.0

  3. Sample size for post-marketing safety studies based on historical controls.

    Science.gov (United States)

    Wu, Yu-te; Makuch, Robert W

    2010-08-01

    As part of a drug's entire life cycle, post-marketing studies are an important part in the identification of rare, serious adverse events. Recently, the US Food and Drug Administration (FDA) has begun to implement new post-marketing safety mandates as a consequence of increased emphasis on safety. The purpose of this research is to provide exact sample size formula for the proposed hybrid design, based on a two-group cohort study with incorporation of historical external data. Exact sample size formula based on the Poisson distribution is developed, because the detection of rare events is our outcome of interest. Performance of exact method is compared to its approximate large-sample theory counterpart. The proposed hybrid design requires a smaller sample size compared to the standard, two-group prospective study design. In addition, the exact method reduces the number of subjects required in the treatment group by up to 30% compared to the approximate method for the study scenarios examined. The proposed hybrid design satisfies the advantages and rationale of the two-group design with smaller sample sizes generally required. 2010 John Wiley & Sons, Ltd.

  4. Sampling methods for the study of pneumococcal carriage: a systematic review.

    Science.gov (United States)

    Gladstone, R A; Jefferies, J M; Faust, S N; Clarke, S C

    2012-11-06

    Streptococcus pneumoniae is an important pathogen worldwide. Accurate sampling of S. pneumoniae carriage is central to surveillance studies before and following conjugate vaccination programmes to combat pneumococcal disease. Any bias introduced during sampling will affect downstream recovery and typing. Many variables exist for the method of collection and initial processing, which can make inter-laboratory or international comparisons of data complex. In February 2003, a World Health Organisation working group published a standard method for the detection of pneumococcal carriage for vaccine trials to reduce or eliminate variability. We sought to describe the variables associated with the sampling of S. pneumoniae from collection to storage in the context of the methods recommended by the WHO and those used in pneumococcal carriage studies since its publication. A search of published literature in the online PubMed database was performed on the 1st June 2012, to identify published studies that collected pneumococcal carriage isolates, conducted after the publication of the WHO standard method. After undertaking a systematic analysis of the literature, we show that a number of differences in pneumococcal sampling protocol continue to exist between studies since the WHO publication. The majority of studies sample from the nasopharynx, but the choice of swab and swab transport media is more variable between studies. At present there is insufficient experimental data that supports the optimal sensitivity of any standard method. This may have contributed to incomplete adoption of the primary stages of the WHO detection protocol, alongside pragmatic or logistical issues associated with study design. Consequently studies may not provide a true estimate of pneumococcal carriage. Optimal sampling of carriage could lead to improvements in downstream analysis and the evaluation of pneumococcal vaccine impact and extrapolation to pneumococcal disease control therefore

  5. Adaptive list sequential sampling method for population-based observational studies

    NARCIS (Netherlands)

    Hof, Michel H.; Ravelli, Anita C. J.; Zwinderman, Aeilko H.

    2014-01-01

    In population-based observational studies, non-participation and delayed response to the invitation to participate are complications that often arise during the recruitment of a sample. When both are not properly dealt with, the composition of the sample can be different from the desired

  6. Cytogenetical and morphological features reveal significant differences among Venezuelan and Brazilian samples of Mugil curema (Teleostei: Mugilidae

    Directory of Open Access Journals (Sweden)

    Mauro Nirchio

    Full Text Available Karyotype of M. curema from the Gulf of Mexico and Brazil have been reported as possessing chromosome complement with 2n=28 and FN=48, whereas specimens from Venezuela has been reported as possessing a diploid number 2n=24 and a conserved FN (48. Although at first sight this variation suggests the presence of a chromosomal intraspecific (interpopulational variability, the possibility that we are dealing with two different species was examined. This work revisit the karyotypes of M. curema from Venezuela and Brazil, including new data on C-banding, and NOR localization, and compares morphologic characteristics of samples from both localities. Thus, besides diploid number, the constitutive heterochromatin distribution and NORs location, mark other differences between M. curema Cytotype 1 (2n=28; FN=48 and Cytotype 2 (2n=24; NF=48. Moreover, morphologic comparison revealed differences in the scale counts and pectoral fin rays: 35 scales in the middle body line and 15 pectoral fin rays in specimens possessing the karyotype 2n=28, compared with 37-39 scales in the middle body line and 17 pectoral fin rays in specimens with the karyotype 2n=24. These differences lead us to suggest that both cytotypes are not related merely to geographic polytipic variations but could correspond to different species.

  7. Adult health study reference papers. Selection of the sample. Characteristics of the sample

    Energy Technology Data Exchange (ETDEWEB)

    Beebe, G W; Fujisawa, Hideo; Yamasaki, Mitsuru

    1960-12-14

    The characteristics and selection of the clinical sample have been described in some detail to provide information on the comparability of the exposure groups with respect to factors excluded from the matching criteria and to provide basic descriptive information potentially relevant to individual studies that may be done within the framework of the Adult Health Study. The characteristics under review here are age, sex, many different aspects of residence, marital status, occupation and industry, details of location and shielding ATB, acute radiation signs and symptoms, and prior ABCC medical or pathology examinations. 5 references, 57 tables.

  8. The Effect of Small Sample Size on Measurement Equivalence of Psychometric Questionnaires in MIMIC Model: A Simulation Study

    Directory of Open Access Journals (Sweden)

    Jamshid Jamali

    2017-01-01

    Full Text Available Evaluating measurement equivalence (also known as differential item functioning (DIF is an important part of the process of validating psychometric questionnaires. This study aimed at evaluating the multiple indicators multiple causes (MIMIC model for DIF detection when latent construct distribution is nonnormal and the focal group sample size is small. In this simulation-based study, Type I error rates and power of MIMIC model for detecting uniform-DIF were investigated under different combinations of reference to focal group sample size ratio, magnitude of the uniform-DIF effect, scale length, the number of response categories, and latent trait distribution. Moderate and high skewness in the latent trait distribution led to a decrease of 0.33% and 0.47% power of MIMIC model for detecting uniform-DIF, respectively. The findings indicated that, by increasing the scale length, the number of response categories and magnitude DIF improved the power of MIMIC model, by 3.47%, 4.83%, and 20.35%, respectively; it also decreased Type I error of MIMIC approach by 2.81%, 5.66%, and 0.04%, respectively. This study revealed that power of MIMIC model was at an acceptable level when latent trait distributions were skewed. However, empirical Type I error rate was slightly greater than nominal significance level. Consequently, the MIMIC was recommended for detection of uniform-DIF when latent construct distribution is nonnormal and the focal group sample size is small.

  9. The Effect of Small Sample Size on Measurement Equivalence of Psychometric Questionnaires in MIMIC Model: A Simulation Study.

    Science.gov (United States)

    Jamali, Jamshid; Ayatollahi, Seyyed Mohammad Taghi; Jafari, Peyman

    2017-01-01

    Evaluating measurement equivalence (also known as differential item functioning (DIF)) is an important part of the process of validating psychometric questionnaires. This study aimed at evaluating the multiple indicators multiple causes (MIMIC) model for DIF detection when latent construct distribution is nonnormal and the focal group sample size is small. In this simulation-based study, Type I error rates and power of MIMIC model for detecting uniform-DIF were investigated under different combinations of reference to focal group sample size ratio, magnitude of the uniform-DIF effect, scale length, the number of response categories, and latent trait distribution. Moderate and high skewness in the latent trait distribution led to a decrease of 0.33% and 0.47% power of MIMIC model for detecting uniform-DIF, respectively. The findings indicated that, by increasing the scale length, the number of response categories and magnitude DIF improved the power of MIMIC model, by 3.47%, 4.83%, and 20.35%, respectively; it also decreased Type I error of MIMIC approach by 2.81%, 5.66%, and 0.04%, respectively. This study revealed that power of MIMIC model was at an acceptable level when latent trait distributions were skewed. However, empirical Type I error rate was slightly greater than nominal significance level. Consequently, the MIMIC was recommended for detection of uniform-DIF when latent construct distribution is nonnormal and the focal group sample size is small.

  10. The microbiome of Brazilian mangrove sediments as revealed by metagenomics.

    Directory of Open Access Journals (Sweden)

    Fernando Dini Andreote

    Full Text Available Here we embark in a deep metagenomic survey that revealed the taxonomic and potential metabolic pathways aspects of mangrove sediment microbiology. The extraction of DNA from sediment samples and the direct application of pyrosequencing resulted in approximately 215 Mb of data from four distinct mangrove areas (BrMgv01 to 04 in Brazil. The taxonomic approaches applied revealed the dominance of Deltaproteobacteria and Gammaproteobacteria in the samples. Paired statistical analysis showed higher proportions of specific taxonomic groups in each dataset. The metabolic reconstruction indicated the possible occurrence of processes modulated by the prevailing conditions found in mangrove sediments. In terms of carbon cycling, the sequences indicated the prevalence of genes involved in the metabolism of methane, formaldehyde, and carbon dioxide. With respect to the nitrogen cycle, evidence for sequences associated with dissimilatory reduction of nitrate, nitrogen immobilization, and denitrification was detected. Sequences related to the production of adenylsulfate, sulfite, and H(2S were relevant to the sulphur cycle. These data indicate that the microbial core involved in methane, nitrogen, and sulphur metabolism consists mainly of Burkholderiaceae, Planctomycetaceae, Rhodobacteraceae, and Desulfobacteraceae. Comparison of our data to datasets from soil and sea samples resulted in the allotment of the mangrove sediments between those samples. The results of this study add valuable data about the composition of microbial communities in mangroves and also shed light on possible transformations promoted by microbial organisms in mangrove sediments.

  11. The microbiome of Brazilian mangrove sediments as revealed by metagenomics.

    Science.gov (United States)

    Andreote, Fernando Dini; Jiménez, Diego Javier; Chaves, Diego; Dias, Armando Cavalcante Franco; Luvizotto, Danice Mazzer; Dini-Andreote, Francisco; Fasanella, Cristiane Cipola; Lopez, Maryeimy Varon; Baena, Sandra; Taketani, Rodrigo Gouvêa; de Melo, Itamar Soares

    2012-01-01

    Here we embark in a deep metagenomic survey that revealed the taxonomic and potential metabolic pathways aspects of mangrove sediment microbiology. The extraction of DNA from sediment samples and the direct application of pyrosequencing resulted in approximately 215 Mb of data from four distinct mangrove areas (BrMgv01 to 04) in Brazil. The taxonomic approaches applied revealed the dominance of Deltaproteobacteria and Gammaproteobacteria in the samples. Paired statistical analysis showed higher proportions of specific taxonomic groups in each dataset. The metabolic reconstruction indicated the possible occurrence of processes modulated by the prevailing conditions found in mangrove sediments. In terms of carbon cycling, the sequences indicated the prevalence of genes involved in the metabolism of methane, formaldehyde, and carbon dioxide. With respect to the nitrogen cycle, evidence for sequences associated with dissimilatory reduction of nitrate, nitrogen immobilization, and denitrification was detected. Sequences related to the production of adenylsulfate, sulfite, and H(2)S were relevant to the sulphur cycle. These data indicate that the microbial core involved in methane, nitrogen, and sulphur metabolism consists mainly of Burkholderiaceae, Planctomycetaceae, Rhodobacteraceae, and Desulfobacteraceae. Comparison of our data to datasets from soil and sea samples resulted in the allotment of the mangrove sediments between those samples. The results of this study add valuable data about the composition of microbial communities in mangroves and also shed light on possible transformations promoted by microbial organisms in mangrove sediments.

  12. Major ions in spitsbergen snow samples

    International Nuclear Information System (INIS)

    Semb, A.; Braekkan, R.; Joranger, E.

    1984-01-01

    Chemical analysis of Spitsbergen snow cores sampled in spring 1983, reveals a spatial pattern consistent with orographic deposition of major anthropogenic pollutants with air movements from southeast towards northwest. The highest concentrations of pollutant species were found at an altitude of 700 metres above sea level, and are higher than for any other recorded snow samples from the Arctic

  13. GASOLINE VEHICLE EXHAUST PARTICLE SAMPLING STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Kittelson, D; Watts, W; Johnson, J; Zarling, D Schauer,J Kasper, K; Baltensperger, U; Burtscher, H

    2003-08-24

    The University of Minnesota collaborated with the Paul Scherrer Institute, the University of Wisconsin (UWI) and Ricardo, Inc to physically and chemically characterize the exhaust plume from recruited gasoline spark ignition (SI) vehicles. The project objectives were: (1) Measure representative particle size distributions from a set of on-road SI vehicles and compare these data to similar data collected on a small subset of light-duty gasoline vehicles tested on a chassis dynamometer with a dilution tunnel using the Unified Drive Cycle, at both room temperature (cold start) and 0 C (cold-cold start). (2) Compare data collected from SI vehicles to similar data collected from Diesel engines during the Coordinating Research Council E-43 project. (3) Characterize on-road aerosol during mixed midweek traffic and Sunday midday periods and determine fleet-specific emission rates. (4) Characterize bulk- and size-segregated chemical composition of the particulate matter (PM) emitted in the exhaust from the gasoline vehicles. Particle number concentrations and size distributions are strongly influenced by dilution and sampling conditions. Laboratory methods were evaluated to dilute SI exhaust in a way that would produce size distributions that were similar to those measured during laboratory experiments. Size fractionated samples were collected for chemical analysis using a nano-microorifice uniform deposit impactor (nano-MOUDI). In addition, bulk samples were collected and analyzed. A mixture of low, mid and high mileage vehicles were recruited for testing during the study. Under steady highway cruise conditions a significant particle signature above background was not measured, but during hard accelerations number size distributions for the test fleet were similar to modern heavy-duty Diesel vehicles. Number emissions were much higher at high speed and during cold-cold starts. Fuel specific number emissions range from 1012 to 3 x 1016 particles/kg fuel. A simple

  14. UV-laser-based microscopic dissection of tree rings - a novel sampling tool for δ(13) C and δ(18) O studies.

    Science.gov (United States)

    Schollaen, Karina; Heinrich, Ingo; Helle, Gerhard

    2014-02-01

    UV-laser-based microscopic systems were utilized to dissect and sample organic tissue for stable isotope measurements from thin wood cross-sections. We tested UV-laser-based microscopic tissue dissection in practice for high-resolution isotopic analyses (δ(13) C/δ(18) O) on thin cross-sections from different tree species. The method allows serial isolation of tissue of any shape and from millimetre down to micrometre scales. On-screen pre-defined areas of interest were automatically dissected and collected for mass spectrometric analysis. Three examples of high-resolution isotopic analyses revealed that: in comparison to δ(13) C of xylem cells, woody ray parenchyma of deciduous trees have the same year-to-year variability, but reveal offsets that are opposite in sign depending on whether wholewood or cellulose is considered; high-resolution tree-ring δ(18) O profiles of Indonesian teak reflect monsoonal rainfall patterns and are sensitive to rainfall extremes caused by ENSO; and seasonal moisture signals in intra-tree-ring δ(18) O of white pine are weighted by nonlinear intra-annual growth dynamics. The applications demonstrate that the use of UV-laser-based microscopic dissection allows for sampling plant tissue at ultrahigh resolution and unprecedented precision. This new technique facilitates sampling for stable isotope analysis of anatomical plant traits like combined tree eco-physiological, wood anatomical and dendroclimatological studies. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

  15. Work Sampling Study of an Engineering Professor during a Regular Contract Period

    Science.gov (United States)

    Brink, Jan; McDonald, Dale B.

    2015-01-01

    Work sampling is a technique that has been employed in industry and fields such as healthcare for some time. It is a powerful technique, and an alternative to conventional stop watch time studies, used by industrial engineers to focus upon random work sampling observations. This study applies work sampling to the duties performed by an individual…

  16. Sample size allocation in multiregional equivalence studies.

    Science.gov (United States)

    Liao, Jason J Z; Yu, Ziji; Li, Yulan

    2018-06-17

    With the increasing globalization of drug development, the multiregional clinical trial (MRCT) has gained extensive use. The data from MRCTs could be accepted by regulatory authorities across regions and countries as the primary sources of evidence to support global marketing drug approval simultaneously. The MRCT can speed up patient enrollment and drug approval, and it makes the effective therapies available to patients all over the world simultaneously. However, there are many challenges both operationally and scientifically in conducting a drug development globally. One of many important questions to answer for the design of a multiregional study is how to partition sample size into each individual region. In this paper, two systematic approaches are proposed for the sample size allocation in a multiregional equivalence trial. A numerical evaluation and a biosimilar trial are used to illustrate the characteristics of the proposed approaches. Copyright © 2018 John Wiley & Sons, Ltd.

  17. Sample preparation of Medicago sativa L. hay for chemical analysis ...

    African Journals Online (AJOL)

    The objective of this study was to quantify the effect of the grinding procedure on the moisture and crude protein concentration of a ground Medicago sativa L. hay sample for quality grading. An additional aim was to investigate the accuracy of electronic moisture testers (EMT). Variance of analyses revealed significant ...

  18. Experience sampling and ecological momentary assessment studies in psychopharmacology: A systematic review.

    Science.gov (United States)

    Bos, Fionneke M; Schoevers, Robert A; aan het Rot, Marije

    2015-11-01

    Experience sampling methods (ESM) and ecological momentary assessment (EMA) offer insight into daily life experiences, including symptoms of mental disorders. The application of ESM/EMA in psychopharmacology can be a valuable addition to more traditional measures such as retrospective self-report questionnaires because they may help reveal the impact of psychotropic medication on patients' actual experiences. In this paper we systematically review the existing literature on the use of ESM/EMA in psychopharmacology research. To this end, we searched the PsycInfo and Medline databases for all available ESM/EMA studies on the use of psychotropic medication in patients with DSM-III-R and DSM-IV disorders. Dissertations were excluded. We included 18 studies that applied ESM/EMA to study the effects of medication on patients with major depressive disorder, substance use disorder, attention-deficit hyperactivity disorder, psychotic disorder, and anxiety disorder. We found that ESM/EMA may allow researchers and clinicians to track patients during different phases of treatment: before treatment to predict outcome, during treatment to examine the effects of treatment on symptoms and different aspects of daily life experience, and after treatment to detect vulnerability for relapse. Moreover, ESM/EMA can potentially help determine how long and in what contexts medications are effective. Thus, ESM/EMA may benefit both researchers and clinicians and might prove to be an effective tool for improving the treatment of psychiatric patients. Copyright © 2015 Elsevier B.V. and ECNP. All rights reserved.

  19. Reproducibility of preclinical animal research improves with heterogeneity of study samples

    Science.gov (United States)

    Vogt, Lucile; Sena, Emily S.; Würbel, Hanno

    2018-01-01

    Single-laboratory studies conducted under highly standardized conditions are the gold standard in preclinical animal research. Using simulations based on 440 preclinical studies across 13 different interventions in animal models of stroke, myocardial infarction, and breast cancer, we compared the accuracy of effect size estimates between single-laboratory and multi-laboratory study designs. Single-laboratory studies generally failed to predict effect size accurately, and larger sample sizes rendered effect size estimates even less accurate. By contrast, multi-laboratory designs including as few as 2 to 4 laboratories increased coverage probability by up to 42 percentage points without a need for larger sample sizes. These findings demonstrate that within-study standardization is a major cause of poor reproducibility. More representative study samples are required to improve the external validity and reproducibility of preclinical animal research and to prevent wasting animals and resources for inconclusive research. PMID:29470495

  20. Soil sample collection and analysis for the Fugitive Dust Characterization Study

    Science.gov (United States)

    Ashbaugh, Lowell L.; Carvacho, Omar F.; Brown, Michael S.; Chow, Judith C.; Watson, John G.; Magliano, Karen C.

    A unique set of soil samples was collected as part of the Fugitive Dust Characterization Study. The study was carried out to establish whether or not source profiles could be constructed using novel analytical methods that could distinguish soil dust sources from each other. The soil sources sampled included fields planted in cotton, almond, tomato, grape, and safflower, dairy and feedlot facilities, paved and unpaved roads (both urban and rural), an agricultural staging area, disturbed land with salt buildup, and construction areas where the topsoil had been removed. The samples were collected using a systematic procedure designed to reduce sampling bias, and were stored frozen to preserve possible organic signatures. For this paper the samples were characterized by particle size (percent sand, silt, and clay), dry silt content (used in EPA-recommended fugitive dust emission factors), carbon and nitrogen content, and potential to emit both PM 10 and PM 2.5. These are not the "novel analytical methods" referred to above; rather, it was the basic characterization of the samples to use in comparing analytical methods by other scientists contracted to the California Air Resources Board. The purpose of this paper is to document the methods used to collect the samples, the collection locations, the analysis of soil type and potential to emit PM 10, and the sample variability, both within field and between fields of the same crop type.

  1. WRAP Module 1 sampling strategy and waste characterization alternatives study

    Energy Technology Data Exchange (ETDEWEB)

    Bergeson, C.L.

    1994-09-30

    The Waste Receiving and Processing Module 1 Facility is designed to examine, process, certify, and ship drums and boxes of solid wastes that have a surface dose equivalent of less than 200 mrem/h. These wastes will include low-level and transuranic wastes that are retrievably stored in the 200 Area burial grounds and facilities in addition to newly generated wastes. Certification of retrievably stored wastes processing in WRAP 1 is required to meet the waste acceptance criteria for onsite treatment and disposal of low-level waste and mixed low-level waste and the Waste Isolation Pilot Plant Waste Acceptance Criteria for the disposal of TRU waste. In addition, these wastes will need to be certified for packaging in TRUPACT-II shipping containers. Characterization of the retrievably stored waste is needed to support the certification process. Characterization data will be obtained from historical records, process knowledge, nondestructive examination nondestructive assay, visual inspection of the waste, head-gas sampling, and analysis of samples taken from the waste containers. Sample characterization refers to the method or methods that are used to test waste samples for specific analytes. The focus of this study is the sample characterization needed to accurately identify the hazardous and radioactive constituents present in the retrieved wastes that will be processed in WRAP 1. In addition, some sampling and characterization will be required to support NDA calculations and to provide an over-check for the characterization of newly generated wastes. This study results in the baseline definition of WRAP 1 sampling and analysis requirements and identifies alternative methods to meet these requirements in an efficient and economical manner.

  2. WRAP Module 1 sampling strategy and waste characterization alternatives study

    International Nuclear Information System (INIS)

    Bergeson, C.L.

    1994-01-01

    The Waste Receiving and Processing Module 1 Facility is designed to examine, process, certify, and ship drums and boxes of solid wastes that have a surface dose equivalent of less than 200 mrem/h. These wastes will include low-level and transuranic wastes that are retrievably stored in the 200 Area burial grounds and facilities in addition to newly generated wastes. Certification of retrievably stored wastes processing in WRAP 1 is required to meet the waste acceptance criteria for onsite treatment and disposal of low-level waste and mixed low-level waste and the Waste Isolation Pilot Plant Waste Acceptance Criteria for the disposal of TRU waste. In addition, these wastes will need to be certified for packaging in TRUPACT-II shipping containers. Characterization of the retrievably stored waste is needed to support the certification process. Characterization data will be obtained from historical records, process knowledge, nondestructive examination nondestructive assay, visual inspection of the waste, head-gas sampling, and analysis of samples taken from the waste containers. Sample characterization refers to the method or methods that are used to test waste samples for specific analytes. The focus of this study is the sample characterization needed to accurately identify the hazardous and radioactive constituents present in the retrieved wastes that will be processed in WRAP 1. In addition, some sampling and characterization will be required to support NDA calculations and to provide an over-check for the characterization of newly generated wastes. This study results in the baseline definition of WRAP 1 sampling and analysis requirements and identifies alternative methods to meet these requirements in an efficient and economical manner

  3. The radioimmunoassay in revealing preclinical disorders of the pituitary-thyroid system functioning

    International Nuclear Information System (INIS)

    Piven', N.V.; Pilatova, N.L.; Lukhverchik, L.N.; Kuz'menkova, E.I.; Solovej, V.V.; Mokhort, T.V.

    2001-01-01

    The main purpose of this research was to study the value of radioimmunoassay (RIA) for assessing the pituitary - thyroid function in healthy persons (aged 18-45). Quantitative criteria have been worked put for estimation of thyroid gland function for the population of Belarus in accordance with regional ecological situation. On this basis, concentrations of thyrotropin, thyroxine, triiodothyronine, thyroglobulin, thyroxine binding globulin were determined by RIA in blood samples. The analysis of the data obtained revealed latent forms of hyperthyroidism (42%) and hypothyroidism (21%), regarded by the authors as late medical consequences of Chernobyl accident. Subclinical stages were diagnosed in most cases. Thus RIA has proved useful for studying the functional state of the regulatory 'pituitary-thyroid gland' system and revealing prenosological disorders in it

  4. Engagement in activities revealing the body and psychosocial adjustment in adults with a trans-tibial prosthesis.

    Science.gov (United States)

    Donovan-Hall, M K; Yardley, L; Watts, R J

    2002-04-01

    The purpose of this study was to examine the effects of the appearance of a prosthesis on social behaviour, social discomfort and psychological well-being in eleven amputees taking delivery of a prosthesis with a silicone cover. Two new scales were developed: the 'Engagement in everyday activities involving revealing the body' (EEARB); and the 'Discomfort-Engagement in everyday activities involving revealing the body' (Discomfort-EEARB) scales. The psychometric properties of these scales were determined using a sample of 101 able-bodied adults. The Hospital Anxiety and Depression Scale and the Rosenberg Self-Esteem Scale were also used to measure psychological well-being in the amputee sample. The EEARB and Discomfort-EEARB proved to have good reliability and validity. Comparison of amputees' scores prior to receiving the silicone cosmesis with those of the able-bodied adults revealed significant behavioural limitations and social discomfort, associated with low self-esteem, anxiety and depression. There was a significant increase in amputees' scores three months afier taking delivery of their prosthesis, indicating that amputees reported engaging in more activities which involved revealing their body, and that they would feel more comfortable in situations which involved revealing the body. As the amputee sample available was small and self-selected, it is not possible to generalise these findings to the amputee population as a whole. However, since there is little previous research investigating the effects of the appearance of the prosthesis, these findings demonstrate the need for further research in this area.

  5. Cushing's disease; inferior petrosal sinus venography and samplings

    International Nuclear Information System (INIS)

    Chung, Tae Sub; Suh, Jung Ho; Kim, Dong Ik; Lee, Hyun Chul; Huh, Kap Bum; Kim, Young Soo; Chung, Sang Sup

    1991-01-01

    Hypersecretion of ACTH in patients with Cushing's syndrome originates from either a pituitary tumor (Cushing's disease) or an ectopic ACTH-secreting tumor. These 2 entities may be clinically indistinguishable, and additional difficulty arise because pituitary microadenomas may be radiologically occult. Recently, bilateral selective venous sampling from the inferior petrosal sinuses became the procedure of choice for confirming a false negative study of a combined hormonal test and pituitary ACTH hypersecretion. We performed selective venous catheterization and sampling for ACTH. The central location of the lesion was detected in 1 case (intersinus gradient = 1.1 : 1), and the remaining 5 cases revealed lateralization of the lesions (intersinus gradient = 3.7 - 20.1 : 1), which correlated well with transsphenoidal microadenomectomies in all the cases. We concluded that selective venous ACTH sampling from the inferior petroal sinus is a reliable and useful aid in the diagnosis of Cushing's disease when standard clinical and biochemical studies are inconclusive

  6. Serum Dried Samples to Detect Dengue Antibodies: A Field Study

    Directory of Open Access Journals (Sweden)

    Angelica Maldonado-Rodríguez

    2017-01-01

    Full Text Available Background. Dried blood and serum samples are useful resources for detecting antiviral antibodies. The conditions for elution of the sample need to be optimized for each disease. Dengue is a widespread disease in Mexico which requires continuous surveillance. In this study, we standardized and validated a protocol for the specific detection of dengue antibodies from dried serum spots (DSSs. Methods. Paired serum and DSS samples from 66 suspected cases of dengue were collected in a clinic in Veracruz, Mexico. Samples were sent to our laboratory, where the conditions for optimal elution of DSSs were established. The presence of anti-dengue antibodies was determined in the paired samples. Results. DSS elution conditions were standardized as follows: 1 h at 4°C in 200 µl of DNase-, RNase-, and protease-free PBS (1x. The optimal volume of DSS eluate to be used in the IgG assay was 40 µl. Sensitivity of 94%, specificity of 93.3%, and kappa concordance of 0.87 were obtained when comparing the antidengue reactivity between DSSs and serum samples. Conclusion. DSS samples are useful for detecting anti-dengue IgG antibodies in the field.

  7. Investigative studies on water contamination in Bangladesh. Primary treatment of water samples at the sampling site

    International Nuclear Information System (INIS)

    Sera, K.; Islam, Md. Shafiqul; Takatsuji, T.; Nakamura, T.; Goto, S.; Takahashi, C.; Saitoh, Y.

    2010-01-01

    Arsenic concentration in 13 well waters, 9 pond waters, 10 agricultural waters and a coconut juice taken in Comilla district, Bangladesh, where the problem of arsenic pollution is the most severe, was investigated. High-level arsenic is detected even in the well water which has been kept drinking by the people. Relatively high arsenic concentration was detected for some pond and farm waters even though the sampling was performed just after the rainy season and the waters were expected to be highly diluted. Clear relationship was observed in elemental compositions between the pond water and the coconut juice collected at the edge of the water. These results are expected to become the basic information for evaluating the risk of individual food such as cultured fishes, shrimps and farm products, and for controlling total intakes of arsenic. In order to solve the problem of transportation of water samples internationally, a simple method of target preparation performed at the sampling site was established and its validity was confirmed. All targets were prepared at the sampling sites in this study on the basis of this method. (author)

  8. Using Negative Emotions to Trace the Experience of Borderline Personality Pathology: Interconnected Relationships Revealed in an Experience Sampling Study.

    Science.gov (United States)

    Law, Mary Kate; Fleeson, William; Arnold, Elizabeth Mayfield; Furr, R Michael

    2016-02-01

    While emotional difficulties are highly implicated in borderline personality disorder (BPD), the dynamic relationships between emotions and BPD symptoms that occur in everyday life are unknown. The current paper examined the function of negative emotions as they relate to BPD symptoms in real time. Experience sampling methodology with 281 participants measured negative emotions and borderline symptoms, expressed as a spectrum of experiences, five times daily for two weeks. Overall, having a BDP diagnosis was associated with experiencing more negative emotions. Multilevel modeling supported positive concurrent relationships between negative emotions and BPD symptoms. Lagged models showed that even after 3 hours negative emotions and several symptoms continued to influence each other. Therefore, results indicated that negative emotions and BPD symptoms are intricately related; some evidenced long-lasting relationships. This research supports emotion-symptom contingencies within BPD and provides insight regarding the reactivity and functionality of negative emotions in borderline pathology.

  9. Sampling strategies to measure the prevalence of common recurrent infections in longitudinal studies

    Directory of Open Access Journals (Sweden)

    Luby Stephen P

    2010-08-01

    Full Text Available Abstract Background Measuring recurrent infections such as diarrhoea or respiratory infections in epidemiological studies is a methodological challenge. Problems in measuring the incidence of recurrent infections include the episode definition, recall error, and the logistics of close follow up. Longitudinal prevalence (LP, the proportion-of-time-ill estimated by repeated prevalence measurements, is an alternative measure to incidence of recurrent infections. In contrast to incidence which usually requires continuous sampling, LP can be measured at intervals. This study explored how many more participants are needed for infrequent sampling to achieve the same study power as frequent sampling. Methods We developed a set of four empirical simulation models representing low and high risk settings with short or long episode durations. The model was used to evaluate different sampling strategies with different assumptions on recall period and recall error. Results The model identified three major factors that influence sampling strategies: (1 the clustering of episodes in individuals; (2 the duration of episodes; (3 the positive correlation between an individual's disease incidence and episode duration. Intermittent sampling (e.g. 12 times per year often requires only a slightly larger sample size compared to continuous sampling, especially in cluster-randomized trials. The collection of period prevalence data can lead to highly biased effect estimates if the exposure variable is associated with episode duration. To maximize study power, recall periods of 3 to 7 days may be preferable over shorter periods, even if this leads to inaccuracy in the prevalence estimates. Conclusion Choosing the optimal approach to measure recurrent infections in epidemiological studies depends on the setting, the study objectives, study design and budget constraints. Sampling at intervals can contribute to making epidemiological studies and trials more efficient, valid

  10. Transport studies in p-type double quantum well samples

    International Nuclear Information System (INIS)

    Hyndman, R.J.

    2000-01-01

    The motivation for the study of double quantum well samples is that the extra spatial degree of freedom can modify the ground state energies of the system, leading to new and interesting many body effects. Electron bi-layers have been widely studied but the work presented here is the first systematic study of transport properties of a p-type, double quantum well system. The samples, grown on the 311 plane, consisted of two 100A GaAs wells separated by a 30A AlAs barrier. The thin barrier in our structures, gives rise to very strong inter-layer Coulombic interactions but in contrast to electron double quantum well samples, tunnelling between the two wells is very weak. This is due to the large effective mass of holes compared with electrons. It is possible to accurately control the total density of a sample and the relative occupancy of each well using front and back gates. A systematic study of the magnetoresistance properties of the p-type bi-layers, was carried out at low temperatures and in high magnetic fields, for samples covering a range of densities. Considerable care was required to obtain reliable results as the samples were extremely susceptible to electrical shock and were prone to drift in density slowly over time. With balanced wells, the very low tunnelling in the p-type bi-layer leads to a complete absence of all odd integers in both resistance and thermopower except for the v=1 state, ( v 1/2 in each layer) where v is the total Landau level filling factor. Unlike other FQHE features the v=1 state strengthens with increased density as inter-layer interactions increase in strength over intra-layer interactions. The state is also destroyed at a critical temperature, which is much lower than the measured activation temperature. This is taken as evidence for a finite temperature phase transition predicted for the bi-layer v=1. From the experimental observations, we construct a phase diagram for the state, which agree closely with theoretical predictions

  11. Suitability of small diagnostic peripheral-blood samples for cell-therapy studies.

    Science.gov (United States)

    Stephanou, Coralea; Papasavva, Panayiota; Zachariou, Myria; Patsali, Petros; Epitropou, Marilena; Ladas, Petros; Al-Abdulla, Ruba; Christou, Soteroulla; Antoniou, Michael N; Lederer, Carsten W; Kleanthous, Marina

    2017-02-01

    Primary hematopoietic stem and progenitor cells (HSPCs) are key components of cell-based therapies for blood disorders and are thus the authentic substrate for related research. We propose that ubiquitous small-volume diagnostic samples represent a readily available and as yet untapped resource of primary patient-derived cells for cell- and gene-therapy studies. In the present study we compare isolation and storage methods for HSPCs from normal and thalassemic small-volume blood samples, considering genotype, density-gradient versus lysis-based cell isolation and cryostorage media with different serum contents. Downstream analyses include viability, recovery, differentiation in semi-solid media and performance in liquid cultures and viral transductions. We demonstrate that HSPCs isolated either by ammonium-chloride potassium (ACK)-based lysis or by gradient isolation are suitable for functional analyses in clonogenic assays, high-level HSPC expansion and efficient lentiviral transduction. For cryostorage of cells, gradient isolation is superior to ACK lysis, and cryostorage in freezing media containing 50% fetal bovine serum demonstrated good results across all tested criteria. For assays on freshly isolated cells, ACK lysis performed similar to, and for thalassemic samples better than, gradient isolation, at a fraction of the cost and hands-on time. All isolation and storage methods show considerable variation within sample groups, but this is particularly acute for density gradient isolation of thalassemic samples. This study demonstrates the suitability of small-volume blood samples for storage and preclinical studies, opening up the research field of HSPC and gene therapy to any blood diagnostic laboratory with corresponding bioethics approval for experimental use of surplus material. Copyright © 2017 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

  12. Large Sample Neutron Activation Analysis: A Challenge in Cultural Heritage Studies

    International Nuclear Information System (INIS)

    Stamatelatos, I.E.; Tzika, F.

    2007-01-01

    Large sample neutron activation analysis compliments and significantly extends the analytical tools available for cultural heritage and authentication studies providing unique applications of non-destructive, multi-element analysis of materials that are too precious to damage for sampling purposes, representative sampling of heterogeneous materials or even analysis of whole objects. In this work, correction factors for neutron self-shielding, gamma-ray attenuation and volume distribution of the activity in large volume samples composed of iron and ceramic material were derived. Moreover, the effect of inhomogeneity on the accuracy of the technique was examined

  13. A revealed-preference study of behavioural impacts of real-time traffic information

    NARCIS (Netherlands)

    Knockaert, J.S.A.; Tseng, Y.; Verhoef, E.T.

    2013-01-01

    In the present study, we investigate the impact of real-time traffic information on traveller behaviour by using repeated day-to-day revealed-preference (RP) observations from a reward experiment. We estimate a trip scheduling model of morning peak behaviour that allows us to determine the impact of

  14. Abrasive supply for ancient Egypt revealed

    International Nuclear Information System (INIS)

    Peltz, C.; Bichler, M.

    2008-01-01

    In the framework of the major research scheme 'Synchronization of Civilizations in the Eastern Mediterranean Region in the 2nd Millennium B.C' instrumental neutron activation analysis (INAA) was used to determine 30 elements in pumice from archaeological excavations to reveal their specific volcanic origin. In ancient time, the widespread pumiceous products of several eruptions in the Aegean region have been used as abrasive tools and were therefore popular trade objects. The correlation of such archaeological findings to a specific eruption of known age would therefore allow to certify a maximum age of the respective stratum ('dating by first appearance'). Pumices from the Aegean region can easily be distinguished by their trace element distribution patterns. This has been shown by previous studies of the group. The elements Al, Ba, Ca, Ce, Co, Cr, Cs, Dy, Eu, Fe, Hf, K, La, Lu, Mn, Na, Nd, Rb, Sb, Sc, Sm, Ta, Tb, Th, Ti, U, V, Yb, Zr and Zn were determined in 16 samples of pumice lumps from excavations in Tell-el-Dab'a and Tell-el-Herr (Egypt). Two irradiation cycles and five measurement runs were applied. To show the accuracy of the results obtained, typical samples of the most important pumice sources in the Aegean region, particularly from Milos, Nisyros, Kos and Thera were analyzed together with the Egyptian samples of unknown origin. A reliable identification of the samples is achieved by comparing these results to the database compiled in previous studies. The geographical positions of these islands are shown. Within the error range, most of the elements determined in typical representatives of Milos, Nisyros, Kos and Santorini were in perfect agreement with values from the literature. On the basis of the Cluster graphics presented, it is possible to relate unknown pumice to its primary source, just by comparing the relation of a few elements, like Ta-Eu and Th-Hf. One concludes that all samples except one can be related to the Minoan eruption of Thera

  15. Geochemical and mineralogical study of selected weathered samples from Olkiluoto site

    International Nuclear Information System (INIS)

    Lindberg, A.

    2009-02-01

    Optical microscopy, chemical analyses and X-ray diffraction method were used to study the influence of weathering from 11 drill core samples from shallow depths (< 25 m). The samples, 4 to 22 cm in length were drilled from Olkiluoto study site, Eurajoki, and they represent the common rock types of local bedrock: mica gneiss, tonalitic and granodioritic gneiss. Two of the samples were macroscopically unweathered and 9 of them were remarkably altered. The alteration was shown as porosity, the abundance of chlorite instead of biotite and pink, unclear feldspars. Many samples also contained red-brown hematite and fractures, some of them coated with secondary minerals, even clay. Microscopically the most visible feature of weathering was the total alteration of plagioclase and cordierite to sericite. In many samples also biotite was richly altered to chlorite and opaque minerals. Microfractures were common and they were filled by hematite, kaolinite and fine-grained muscovite (sericite). Hematite was, in some cases, also largely replacing the weathered minerals, feldspars and cordierite. Chemical alteration was not clear, because the alteration of main minerals have produced secondary minerals with almost the same chemical composition without any reasonable depleting or enrichment of certain elements. X-ray diffraction determination of samples proved, that often plagioclase was replaced by mica and biotite by chlorite. In some cases the samples contained products of chemical weathering, kaolinite and smectite. (orig.)

  16. Study of the formation of duricrusts on the martian surface and their effect on sampling equipment

    Science.gov (United States)

    Kömle, Norbert; Pitcher, Craig; Gao, Yang; Richter, Lutz

    2017-01-01

    The Powdered Sample Dosing and Distribution System (PSDDS) of the ExoMars rover will be required to handle and contain samples of Mars regolith for long periods of time. Cementation of the regolith, caused by water and salts in the soil, results in clumpy material and a duricrust layer forming on the surface. It is therefore possible that material residing in the sampling system may cement, and could potentially hinder its operation. There has yet to be an investigation into the formation of duricrusts under simulated Martian conditions, or how this may affect the performance of sample handling mechanisms. Therefore experiments have been performed to create a duricrust and to explore the cementation of Mars analogues, before performing a series of tests on a qualification model of the PSDDS under simulated Martian conditions. It was possible to create a consolidated crust of cemented material several millimetres deep, with the material below remaining powder-like. It was seen that due to the very low permeability of the Montmorillonite component material, diffusion of water through the material was quickly blocked, resulting in a sample with an inhomogeneous water content. Additionally, samples with a water mass content of 10% or higher would cement into a single solid piece. Finally, tests with the PSDDS revealed that samples with a water mass content of just 5% created small clumps with significant internal cohesion, blocking the sample funnels and preventing transportation of the material. These experiments have highlighted that the cementation of regolith in Martian conditions must be taken into consideration in the design of sample handling instruments.

  17. Detection and Molecular Characterization of Gemycircularvirus from Environmental Samples in Brazil.

    Science.gov (United States)

    da Silva Assis, Matheus Ribeiro; Vieira, Carmen Baur; Fioretti, Julia Monassa; Rocha, Mônica Simões; de Almeida, Pedro Ivo Neves; Miagostovich, Marize Pereira; Fumian, Tulio Machado

    2016-12-01

    Gemycircularvirus (GemyCV) is a group of viruses which has been recently proposed as a new viral genus detected in fecal and environmental samples around the world. GemyCVs have been detected in human blood, brain tissue, cerebrospinal fluid, and stool sample. In the present study, we demonstrate for the first time, through molecular detection and characterization, the presence of GemyCVs in environmental samples from Brazil. Our results show a percentage of positivity ranging from 69 (25/36) to 97 % (35/36) in river water samples collected in Manaus, Amazon region, and wastewater from a wastewater treatment plant located in Rio de Janeiro, respectively, revealing GemyCVs as an important environmental contaminant.

  18. Interval sampling methods and measurement error: a computer simulation.

    Science.gov (United States)

    Wirth, Oliver; Slaven, James; Taylor, Matthew A

    2014-01-01

    A simulation study was conducted to provide a more thorough account of measurement error associated with interval sampling methods. A computer program simulated the application of momentary time sampling, partial-interval recording, and whole-interval recording methods on target events randomly distributed across an observation period. The simulation yielded measures of error for multiple combinations of observation period, interval duration, event duration, and cumulative event duration. The simulations were conducted up to 100 times to yield measures of error variability. Although the present simulation confirmed some previously reported characteristics of interval sampling methods, it also revealed many new findings that pertain to each method's inherent strengths and weaknesses. The analysis and resulting error tables can help guide the selection of the most appropriate sampling method for observation-based behavioral assessments. © Society for the Experimental Analysis of Behavior.

  19. Diverse sampling of East African haemosporidians reveals chiropteran origin of malaria parasites in primates and rodents.

    Science.gov (United States)

    Lutz, Holly L; Patterson, Bruce D; Kerbis Peterhans, Julian C; Stanley, William T; Webala, Paul W; Gnoske, Thomas P; Hackett, Shannon J; Stanhope, Michael J

    2016-06-01

    Phylogenies of parasites provide hypotheses on the history of their movements between hosts, leading to important insights regarding the processes of host switching that underlie modern-day epidemics. Haemosporidian (malaria) parasites lack a well resolved phylogeny, which has impeded the study of evolutionary processes associated with host-switching in this group. Here we present a novel phylogenetic hypothesis that suggests bats served as the ancestral hosts of malaria parasites in primates and rodents. Expanding upon current taxon sampling of Afrotropical bat and bird parasites, we find strong support for all major nodes in the haemosporidian tree using both Bayesian and maximum likelihood approaches. Our analyses support a single transition of haemosporidian parasites from saurian to chiropteran hosts, and do not support a monophyletic relationship between Plasmodium parasites of birds and mammals. We find, for the first time, that Hepatocystis and Plasmodium parasites of mammals represent reciprocally monophyletic evolutionary lineages. These results highlight the importance of broad taxonomic sampling when analyzing phylogenetic relationships, and have important implications for our understanding of key host switching events in the history of malaria parasite evolution. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Benchmarking sample preparation/digestion protocols reveals tube-gel being a fast and repeatable method for quantitative proteomics.

    Science.gov (United States)

    Muller, Leslie; Fornecker, Luc; Van Dorsselaer, Alain; Cianférani, Sarah; Carapito, Christine

    2016-12-01

    Sample preparation, typically by in-solution or in-gel approaches, has a strong influence on the accuracy and robustness of quantitative proteomics workflows. The major benefit of in-gel procedures is their compatibility with detergents (such as SDS) for protein solubilization. However, SDS-PAGE is a time-consuming approach. Tube-gel (TG) preparation circumvents this drawback as it involves directly trapping the sample in a polyacrylamide gel matrix without electrophoresis. We report here the first global label-free quantitative comparison between TG, stacking gel (SG), and basic liquid digestion (LD). A series of UPS1 standard mixtures (at 0.5, 1, 2.5, 5, 10, and 25 fmol) were spiked in a complex yeast lysate background. TG preparation allowed more yeast proteins to be identified than did the SG and LD approaches, with mean numbers of 1979, 1788, and 1323 proteins identified, respectively. Furthermore, the TG method proved equivalent to SG and superior to LD in terms of the repeatability of the subsequent experiments, with mean CV for yeast protein label-free quantifications of 7, 9, and 10%. Finally, known variant UPS1 proteins were successfully detected in the TG-prepared sample within a complex background with high sensitivity. All the data from this study are accessible on ProteomeXchange (PXD003841). © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Reservoir-flooded river mouth areas as sediment traps revealing erosion from peat mining areas - Jukajoki case study in eastern Finland

    Science.gov (United States)

    Tahvanainen, Teemu; Meriläinen, Henna-Kaisa; Haraguchi, Akira; Simola, Heikki

    2016-04-01

    Many types of soil-disturbing land use have caused excess sedimentation in Finnish lakes. Identification and quantification of catchment sources of sediment material is crucial in cases where demands for remediation measures are considered. We studied recent (50 yr) sediments of four small rivers, all draining to a reservoir impounded in 1971. Catchments of two of the rivers had had peat mining activities from early 1980s until recently, exposing large areas of peat surfaces to erosion. The water level of the reservoir had risen to the river mouth areas of all rivers, while in each case, the river mouth areas still form riverine narrows separable from the main reservoir, hence collecting sedimentation from their own catchments. The original soils under the reservoir water level could readily be observed in core samples, providing a dated horizon under recent sediments. In addition, we used 137Cs-stratigraphies for dating of samples from original river bed locations. As expected, recent sediments of rivers with peat mining influence differed from others e.g. by high organic content and C:N ratios. Stable isotopes 13C and 15N both correlated with C:N (r = 0.799 and r = -0.717, respectively) and they also differentiated the peat-mining influenced samples from other river sediments. Principal components of the physical-chemical variables revealed clearer distinction than any variables separately. Light-microscopy revealed abundance of leafs of Sphagnum mosses in peat-mining influenced river sediments that were nearly absent from other rivers. Spores of Sphagnum were, however, abundant in all river sediments indicating their predominantly airborne origin. We find that combination of several physical-chemical characters rather than any single variable and microscopy of plant remains can result in reliable recognition of peatland-origin of sediment material when non-impacted sites are available for comparison. Dating of disturbed recent sediments is challenging. River

  2. Pyrosequencing of environmental soil samples reveals biodiversity of the Phytophthora resident community in chestnut forests.

    Science.gov (United States)

    Vannini, Andrea; Bruni, Natalia; Tomassini, Alessia; Franceschini, Selma; Vettraino, Anna Maria

    2013-09-01

    Pyrosequencing analysis was performed on soils from Italian chestnut groves to evaluate the diversity of the resident Phytophthora community. Sequences analysed with a custom database discriminated 15 pathogenic Phytophthoras including species common to chestnut soils, while a total of nine species were detected with baiting. The two sites studied differed in Phytophthora diversity and the presence of specific taxa responded to specific ecological traits of the sites. Furthermore, some species not previously recorded were represented by a discrete number of reads; among these species, Phytophthora ramorum was detected at both sites. Pyrosequencing was demonstrated to be a very sensitive technique to describe the Phytophthora community in soil and was able to detect species not easy to be isolated from soil with standard baiting techniques. In particular, pyrosequencing is an highly efficient tool for investigating the colonization of new environments by alien species, and for ecological and adaptive studies coupled with biological detection methods. This study represents the first application of pyrosequencing for describing Phytophthoras in environmental soil samples. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  3. Evaluation the virulence of Mycobacterium bovis isolated from milk samples through histopathological study in laboratory animals.

    Science.gov (United States)

    Al-Saqur, I M; Al-Thwani, A N; Al-Attar, I M; Al-Mashhadani, M S

    2016-12-01

    Mycobacterium bovis has a broad host range, and it is the principal agent responsible for tuberculosis (TB) in bovine, domestic and wild mammals. M. bovis also infects human, causing zoonotic TB through ingestion, inhalation and, less frequently by contact with mucous membranes and broken skin. Zoonotic TB was formerly an endemic disease, usually transmitted to man by consumption of raw cow's milk. It is indistinguishable clinically or pathologically from TB caused by M. tuberculosis. The aims of this study were, to isolate and identified M. bovis from raw milk samples by different methods, and evaluate the virulence of M. bovis in laboratory animals (Rabbit). To conduct the study, ninety three cow's milk samples were collected from farms around Baghdad governorate. The decontamination of milk samples was firstly carried out, then samples were subjected to routine tests which include, direct smear for Ziehl Neelsen acid fast stain, culture, each sample was cultured on Lowenstein Jensen media with Sodium pyruvite (All cultures incubated on 37°C for 4-10weeks with continuous observation), and biochemical testes as Nitrate reduction test, Niacin paper strip test and pyrazinamidase test, were employed to diagnose and identified the bacteria. Beside molecular assay was used to confirm the identification of the isolates by Polymerase Chain Reaction (PCR) using specific primers for M. bovis. The virulence of these isolates were investigated through inoculate it in group of laboratory animals consist of 8 rabbit in addition to other group of 4 animals as control (inoculate with Phosphate Buffer Saline). The animals were scarified after 6weeks of inoculation, post- mortem examination was carried out, smears were taken from lesions, and tissue samples were collected from lymph nodes and different organs. The results revealed five isolates of M. bovis in direct smear by acid fast Ziehl-Neelsen stain, while eight isolates observed by culture, the colonies appeared with

  4. Sample size determination for disease prevalence studies with partially validated data.

    Science.gov (United States)

    Qiu, Shi-Fang; Poon, Wai-Yin; Tang, Man-Lai

    2016-02-01

    Disease prevalence is an important topic in medical research, and its study is based on data that are obtained by classifying subjects according to whether a disease has been contracted. Classification can be conducted with high-cost gold standard tests or low-cost screening tests, but the latter are subject to the misclassification of subjects. As a compromise between the two, many research studies use partially validated datasets in which all data points are classified by fallible tests, and some of the data points are validated in the sense that they are also classified by the completely accurate gold-standard test. In this article, we investigate the determination of sample sizes for disease prevalence studies with partially validated data. We use two approaches. The first is to find sample sizes that can achieve a pre-specified power of a statistical test at a chosen significance level, and the second is to find sample sizes that can control the width of a confidence interval with a pre-specified confidence level. Empirical studies have been conducted to demonstrate the performance of various testing procedures with the proposed sample sizes. The applicability of the proposed methods are illustrated by a real-data example. © The Author(s) 2012.

  5. Preparation Of Deposited Sediment Sample By Casting Method For Environmental Study

    International Nuclear Information System (INIS)

    Hutabarat, Tommy; Ristin PI, Evarista

    2000-01-01

    The preparation of deposited sediment sample by c asting m ethod for environmental study has been carried out. This method comprises separation of size fraction and casting process. The deposited sediment samples were wet sieved to separate the size fraction of >500 mum, (250-500) mum, (125-250) mum and (63-125) mum and settling procedures were followed for the separation of (40-63) mum, (20-40) mum, (10-20) mum and o C, ashed at 450 o C, respectively. In the casting process of sample, it was used polyester rapid cure resin and methyl ethyl ketone peroxide (MEKP) hardener. The moulded sediment sample was poured onto caster, allow for 60 hours long. The aim of this method is to get the casted sample which can be used effectively, efficiently and to be avoided from contamination of each other samples. Before casting, samples were grinded up to be fine. The result shows that casting product is ready to be used for natural radionuclide analysis

  6. [Mastitis revealing Churg-Strauss syndrome].

    Science.gov (United States)

    Dannepond, C; Le Fourn, E; de Muret, A; Ouldamer, L; Carmier, D; Machet, L

    2014-01-01

    Churg-Strauss syndrome often involves the skin, and this may sometimes reveal the disease. A 25-year-old woman was referred to a gynaecologist for inflammation of the right breast with breast discharge. Cytological analysis of the liquid showed numerous inflammatory cells, particularly polymorphonuclear eosinophils and neutrophils. Ultrasound examination of the breast was consistent with galactophoritis. CRP was normal, and hypereosinophilia was seen. The patient was subsequently referred to a dermatology unit. Skin examination revealed inflammation of the entire breast, which was painful, warm and erythematous; the border was oedematous with blisters. Necrotic lesions were also present on the thumbs and knees. Skin biopsy of the breast showed a dermal infiltrate with abundant infiltrate of polymorphonuclear eosinophils, including patchy necrosis and intraepidermal vesicles. Histological examination of a biopsy sample from a thumb revealed eosinophilic granuloma and leukocytoclastic vasculitis. The patient was also presenting asthma, pulmonary infiltrates and mononeuropathy at L3, consistent with Churg-Strauss syndrome. Breast involvement in Churg-Strauss syndrome is very rare (only one other case has been reported). This is the first case in which the breast condition revealed the disease. Cutaneous involvement of the breast is, however, also compatible with Wells' cellulitis. The lesions quickly disappeared with 1mg/kg/d oral prednisolone. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  7. COMPARATIVE STUDY OF ENDOMETRIAL SAMPLING USING PIPELLE WITH HYSTEROSCOPIC-GUIDED BIOPSY

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    Nalina S

    2017-07-01

    Full Text Available BACKGROUND Hysteroscopic-guided biopsy is the gold standard for endometrial sampling, but it carries risk of general anaesthesia, infection and perforation, whereas Pipelle does not require anaesthesia or cervical dilatation and it allows outpatient and painless endometrial sampling. The aim of the study is to determine the reliability and accuracy of Pipelle aspiration in acquiring an adequate and representative endometrial sample and to compare its histopathology with hysteroscopic-directed biopsy. MATERIALS AND METHODS A prospective observational comparative study evaluating the role of Pipelle aspiration as an outpatient procedure in endometrial sampling of perimenopausal women with AUB. 150 perimenopausal women with clinical diagnosis of abnormal uterine bleeding were selected from the Gynaecology OPD of IOG, Chennai, between October 2014 and September 2015. They were subjected to endometrial sampling by Pipelle followed by hysteroscopic-directed biopsy. The efficacy of Pipelle was determined by correlating the histopathological results obtained from it and the hysteroscopic-directed biopsy. RESULTS The histopathology of the endometrium obtained using Pipelle’s curette showed a sensitivity of 93%, specificity of 90% in the detection of abnormal findings with PPV of 88% and NPV of 94%. However, accuracy of Pipelle is found to be less in the diagnosis of polyps and submucous fibroids with accuracy of nearing 100% when using hysteroscopy. CONCLUSION Pipelle endometrial sampling is convenient, easy, painless and safe in obtaining an adequate sample for histopathology with high sensitivity and specificity for endometrial pathologies and endometrial carcinoma.

  8. A study for natural radioactivity levels in some soil samples using gamma spectrometry

    International Nuclear Information System (INIS)

    Mohamed, Yousif Hassab El Rasoul

    1997-05-01

    The purpose of this study was to investigate a few selected soil samples and to study their natural radioactivity using gamma spectrometry. The first sample was a rock phosphate from Nuba mountains region which is being considered as a low cost fertilizer. Another sample came from Miri lake area (Nuba mountains) which is known to have elevated natural radioactivity level. The other four samples came from different other regions in Sudan for comparison. The idea was to identify the radioactive nuclides present in these soil samples, to trace their sources and to determine the activity present in them. (Author)

  9. Random Sampling of Squamate Reptiles in Spanish Natural Reserves Reveals the Presence of Novel Adenoviruses in Lacertids (Family Lacertidae) and Worm Lizards (Amphisbaenia).

    Science.gov (United States)

    Szirovicza, Leonóra; López, Pilar; Kopena, Renáta; Benkő, Mária; Martín, José; Pénzes, Judit J

    2016-01-01

    Here, we report the results of a large-scale PCR survey on the prevalence and diversity of adenoviruses (AdVs) in samples collected randomly from free-living reptiles. On the territories of the Guadarrama Mountains National Park in Central Spain and of the Chafarinas Islands in North Africa, cloacal swabs were taken from 318 specimens of eight native species representing five squamate reptilian families. The healthy-looking animals had been captured temporarily for physiological and ethological examinations, after which they were released. We found 22 AdV-positive samples in representatives of three species, all from Central Spain. Sequence analysis of the PCR products revealed the existence of three hitherto unknown AdVs in 11 Carpetane rock lizards (Iberolacerta cyreni), nine Iberian worm lizards (Blanus cinereus), and two Iberian green lizards (Lacerta schreiberi), respectively. Phylogeny inference showed every novel putative virus to be a member of the genus Atadenovirus. This is the very first description of the occurrence of AdVs in amphisbaenian and lacertid hosts. Unlike all squamate atadenoviruses examined previously, two of the novel putative AdVs had A+T rich DNA, a feature generally deemed to mirror previous host switch events. Our results shed new light on the diversity and evolution of atadenoviruses.

  10. Random Sampling of Squamate Reptiles in Spanish Natural Reserves Reveals the Presence of Novel Adenoviruses in Lacertids (Family Lacertidae and Worm Lizards (Amphisbaenia.

    Directory of Open Access Journals (Sweden)

    Leonóra Szirovicza

    Full Text Available Here, we report the results of a large-scale PCR survey on the prevalence and diversity of adenoviruses (AdVs in samples collected randomly from free-living reptiles. On the territories of the Guadarrama Mountains National Park in Central Spain and of the Chafarinas Islands in North Africa, cloacal swabs were taken from 318 specimens of eight native species representing five squamate reptilian families. The healthy-looking animals had been captured temporarily for physiological and ethological examinations, after which they were released. We found 22 AdV-positive samples in representatives of three species, all from Central Spain. Sequence analysis of the PCR products revealed the existence of three hitherto unknown AdVs in 11 Carpetane rock lizards (Iberolacerta cyreni, nine Iberian worm lizards (Blanus cinereus, and two Iberian green lizards (Lacerta schreiberi, respectively. Phylogeny inference showed every novel putative virus to be a member of the genus Atadenovirus. This is the very first description of the occurrence of AdVs in amphisbaenian and lacertid hosts. Unlike all squamate atadenoviruses examined previously, two of the novel putative AdVs had A+T rich DNA, a feature generally deemed to mirror previous host switch events. Our results shed new light on the diversity and evolution of atadenoviruses.

  11. Studies and further needed investigations on radioactive contaminants in soil samples

    International Nuclear Information System (INIS)

    Belivermis, M.; Kilic, O.; Topcuoglu, S.; Cotuk, Y.; Kalayci, G.; Pestreli, D.

    2009-01-01

    Following the Chernobyl nuclear reactor accident, the radionuclides were deposited on the marine and terrestrial environments of Turkey and other countries as wet and / or dry fallout. It is well known that, the soil is the main reservoir at the terrestrial environment. The geographic distribution of the Chernobyl radionuclides per unit area is significantly different. Many countries have drawn radiation maps using the radionuclide data of the soil samples. The radioecological monitoring study in the soil samples are also investigated in the our country. However, the exist data is limited for whole region of Turkey. In general, the type study, that make, in uncultivated soil sample use of different soil layers (0-5, 5-10, 10-20, 20-30 cm). In our previous studies, the activity concentration of gamma emitting radionuclides were determined in soil samples (0-5 cm) from the Thrace (73 sites) and East and South Marmara (100 sites) regions. Moreover, the mean values of the annual effective dose equivalent were also calculated. In literature, numerous studies have been published concerning vertical migration of 1 37Cs in uncultivated soil samples use of different soil types. However, we have not enough data on this subject. On the other hand, we want to present a previously published data on the vertical distribution of 1 37Cs radionuclide in an uncultivated site in the eastern Black Sea region. It is well known that the determination of soil to plant transfer factors of radiocesium that take account all economically crops on the soil varieties is a need to support dose assessment or countermeasure studies. Previously published IAEA reports, we determined transfer factors for some crops of 1 37Cs radionuclides in cultivated soil samples (0-20 cm depth) in the eastern Black Sea region. At the same time, we have given a new project to IAEA for the determination of transfer factor of radiocesium from soil to some crops for Akkuyu Nuclear Power Plant site.

  12. A confirmatory holding time study for purgeable VOCs in water samples

    International Nuclear Information System (INIS)

    West, O.R.; Bayne, C.K.; Siegrist, R.L.; Holden, W.H.; Bottrell, D.W.

    1996-01-01

    Analyte stability during pre-analytical storage is essential to the accurate quantification contaminants in environmental samples. This is particularly true for volatile organic compounds (VOCS) which can easily volatilize and/or degrade during sample storage. Recognizing this, regulatory agencies require water samples be collected in vials without headspace and stored at 4 degrees C, and that analyses be conducted within 14 days, 2048 even if samples are acid-preserved. Since the selection of a 14-day holding time was largely arbitrary, the appropriateness of this requirement must be re-evaluated. The goal of the study described here was to provide regulatory agencies with the necessary data to extend the maximum holding time for properly preserved VOC water samples to 28 days

  13. Descriptions of Sampling Practices Within Five Approaches to Qualitative Research in Education and the Health Sciences

    Directory of Open Access Journals (Sweden)

    Timothy C. Guetterman

    2015-05-01

    Full Text Available Although recommendations exist for determining qualitative sample sizes, the literature appears to contain few instances of research on the topic. Practical guidance is needed for determining sample sizes to conduct rigorous qualitative research, to develop proposals, and to budget resources. The purpose of this article is to describe qualitative sample size and sampling practices within published studies in education and the health sciences by research design: case study, ethnography, grounded theory methodology, narrative inquiry, and phenomenology. I analyzed the 51 most highly cited studies using predetermined content categories and noteworthy sampling characteristics that emerged. In brief, the findings revealed a mean sample size of 87. Less than half of the studies identified a sampling strategy. I include a description of findings by approach and recommendations for sampling to assist methodologists, reviewers, program officers, graduate students, and other qualitative researchers in understanding qualitative sampling practices in recent studies. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs1502256

  14. The Determination of the Biochemical Properties of Some Monofloral Honey Samples Produced across Turkey

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    Aziz Gül

    2016-12-01

    Full Text Available This study was conducted in 2013 to determine the biochemical properties of 10 different monofloral honey types produced across Turkey. For the study, honey samples were obtained from beekeepers and the identity and relative percentage of dominant pollen types in samples was determined through microscopic analysis. Pollen analysis revealed that honey types chaste tree (Vitex agnus-castus and sunflower (Helianthus annuus contained high proportions of each respective pollen type. These proportions reached as high as 86%, while other honey types such as Anason had low Anasom pollen content, occurring at 45% in whole honey samples. Biochemical analysis revealed that the average honey sample quality characteristics were as followings: ash 0.37±0.04, electricity conductivity 0.79±0.07 mS/cm, moisture 19.15±0.09%, pH 3.97±0.02, acidity 29.07±0.39 meq/kg, hydroxymethylfurfural (HMF, 6.17±0.76 mg/kg, diastase 22.05±0.00, invert sugar 69.72±0.49% and sucrose 2.90±0.30%. These analyses confirmed that honey samples met standards outlined by the Turkish Food Codex Honey Standard, European Union Honey Standard and Codex Standards respectively.

  15. An international study of the performance of sample collection from patients

    NARCIS (Netherlands)

    Dzik, WH; Murphy, MF; Andreu, G; Heddle, N; Hogman, C; Kekomaki, R; Murphy, S; Shimizu, M; Smit Sibinga, C.T.

    2003-01-01

    Background and Objectives Collection of a blood sample from the correct patient is the first step in the process of safe transfusion. The aim of this international collaborative study was to assess the frequency of mislabelled and miscollected samples drawn for blood grouping. Materials and Methods

  16. ROPES reveals past land cover and pollen productivity estimates from single pollen records

    Science.gov (United States)

    Theuerkauf, Martin; Couwenberg, John

    2018-04-01

    Quantitative reconstructions of past vegetation cover commonly require pollen productivity estimates (PPEs). PPEs are calibrated in extensive and rather cumbersome surface-sample studies, and are so far only available for selected regions. Moreover, it may be questioned whether present-day pollen-landcover relationships are valid for palaeo-situations. We here introduce the ROPES approach that simultaneously derives PPEs and mean plant abundances from single pollen records. ROPES requires pollen counts and pollen accumulation rates (PARs, grains cm-2 year-1). Pollen counts are used to reconstruct plant abundances following the REVEALS approach. The principle of ROPES is that changes in plant abundance are linearly represented in observed PAR values. For example, if the PAR of pine doubles, so should the REVEALS reconstructed abundance of pine. Consequently, if a REVEALS reconstruction is ‘correct’ (i.e. ‘correct’ PPEs are used) the ratio ‘PAR over REVEALS’ is constant for each taxon along all samples of a record. With incorrect PPEs, the ratio will instead vary. ROPES starts from random (likely incorrect) PPEs, but then adjusts them using an optimization algorithm with the aim to minimize variation in the ‘PAR over REVEALS’ ratio across the record. ROPES thus simultaneously calculates mean plant abundances and PPEs. We illustrate the approach with test applications on nine synthetic pollen records. The results show that good performance of ROPES requires data sets with high underlying variation, many samples and low noise in the PAR data. ROPES can deliver first landcover reconstructions in regions for which PPEs are not yet available. The PPEs provided by ROPES may then allow for further REVEALS-based reconstructions. Similarly, ROPES can provide insight in pollen productivity during distinct periods of the past such as the Lateglacial. We see a potential to study spatial and temporal variation in pollen productivity for example in relation to site

  17. In-Service Turkish Elementary and Science Teachers' Attitudes toward Science and Science Teaching: A Sample from Usak Province

    Science.gov (United States)

    Turkmen, Lutfullah

    2013-01-01

    The purpose of this study is to reveal Turkish elementary teachers' and science teachers' attitudes toward science and science teaching. The sample of the study, 138 in-service elementary level science teachers from a province of Turkey, was selected by a clustered sampling method. The Science Teaching Attitude Scale-II was employed to measure the…

  18. One Sample, One Shot - Evaluation of sample preparation protocols for the mass spectrometric proteome analysis of human bile fluid without extensive fractionation.

    Science.gov (United States)

    Megger, Dominik A; Padden, Juliet; Rosowski, Kristin; Uszkoreit, Julian; Bracht, Thilo; Eisenacher, Martin; Gerges, Christian; Neuhaus, Horst; Schumacher, Brigitte; Schlaak, Jörg F; Sitek, Barbara

    2017-02-10

    The proteome analysis of bile fluid represents a promising strategy to identify biomarker candidates for various diseases of the hepatobiliary system. However, to obtain substantive results in biomarker discovery studies large patient cohorts necessarily need to be analyzed. Consequently, this would lead to an unmanageable number of samples to be analyzed if sample preparation protocols with extensive fractionation methods are applied. Hence, the performance of simple workflows allowing for "one sample, one shot" experiments have been evaluated in this study. In detail, sixteen different protocols implying modifications at the stages of desalting, delipidation, deglycosylation and tryptic digestion have been examined. Each method has been individually evaluated regarding various performance criteria and comparative analyses have been conducted to uncover possible complementarities. Here, the best performance in terms of proteome coverage has been assessed for a combination of acetone precipitation with in-gel digestion. Finally, a mapping of all obtained protein identifications with putative biomarkers for hepatocellular carcinoma (HCC) and cholangiocellular carcinoma (CCC) revealed several proteins easily detectable in bile fluid. These results can build the basis for future studies with large and well-defined patient cohorts in a more disease-related context. Human bile fluid is a proximal body fluid and supposed to be a potential source of disease markers. However, due to its biochemical composition, the proteome analysis of bile fluid still represents a challenging task and is therefore mostly conducted using extensive fractionation procedures. This in turn leads to a high number of mass spectrometric measurements for one biological sample. Considering the fact that in order to overcome the biological variability a high number of biological samples needs to be analyzed in biomarker discovery studies, this leads to the dilemma of an unmanageable number of

  19. Who Are We Studying? Sample Diversity in Teaching of Psychology Research

    Science.gov (United States)

    Richmond, Aaron S.; Broussard, Kristin A.; Sterns, Jillian L.; Sanders, Kristina K.; Shardy, Justin C.

    2015-01-01

    The purpose of the current study was to examine the sample diversity of empirical articles published in four premier teaching of psychology journals from 2008 to 2013. We investigated which demographic information was commonly reported and if samples were ethnically representative and whether gender was representative compared to National…

  20. Environmental sampling of Ceratonia siliqua (carob) trees in Spain reveals the presence of the rare Cryptococcus gattii genotype AFLP7/VGIV.

    Science.gov (United States)

    Linares, Carlos; Colom, María Francisca; Torreblanca, Marina; Esteban, Violeta; Romera, Álvaro; Hagen, Ferry

    2015-01-01

    Cryptococcus gattii is a pathogenic basidiomycetous yeast that is emerging in temperate climate zones worldwide. C. gattii has repetitively been isolated from numerous tree species. Ongoing environmental sampling and molecular characterization is essential to understand the presence of this primary pathogenic microorganism in the Mediterranean environment. To report the first isolation of the rare C. gattii genotype AFLP7/VGIV from the environment in Europe. Samples were collected from woody debris of carob trees (Ceratonia siliqua) and olive trees (Olea europaea) in El Perelló, Tarragona, Spain. Cryptococcus species were further characterized by using URA5-RFLP, MALDI-TOF, AFLP and MLST. The antifungal susceptibility profile to amphotericin B, 5-fluorocytosine, fluconazole, itraconazole, posaconazole and voriconazole was determined using Sensititre Yeast One and E-test. Cultures from one carob tree revealed the presence of ten Cryptococcus-like colonies. One colony was identified as C. gattii, and subsequent molecular characterization showed that it was an α mating-type that belonged to the rare genotype AFLP7/VGIV. Antifungal susceptibility testing showed values within the range of sensitivity described for other isolates of the same genotype and within the epidemiological cutoff values for this species. The isolation of the rare C. gattii genotype AFLP7/VGIV in Spain is the first report in the European environment, implying the possible presence in other regions of the Mediterranean area, and underlines that clinicians must be aware for C. gattii infections in healthy individuals. Copyright © 2014 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

  1. A comparative study of general intelligence in Spanish and Moroccan samples.

    Science.gov (United States)

    Diaz, Amelia; Sellami, Khadija; Infanzón, Eugenia; Lanzón, Teresa; Lynn, Richard

    2012-07-01

    The aim of this study is to fill a gap in intelligence research by presenting data for the average IQ in Morocco and for a comparable sample in Spain. Adult samples were administered the Raven Standard Progressive Matrices (SPM) (Raven, Court, & Raven, 2001) and scored for the total test and for the three sub-factors of gestalt continuation, verbal-analytical reasoning and visuospatial ability identified by Lynn, Allik, and Irwing (2004). The total test and the three factors have shown satisfactory reliability. Our results for the Moroccan sample show significant relationship between general intelligence factor, gestalt continuation and visuospatial ability with education level and income. Conversely, these variables have been shown to be independent for the Spanish sample. This sample obtained significantly higher scores for the four factors assessed than the Moroccan one. These differences have been found also comparing samples with the same education levels. Finally, the errors percentage for Moroccans has been higher than for Spaniards in all the items, suggesting that the level of difficulty was higher for the Moroccan sample.

  2. Genotyping of samples from German patients with ocular, cerebral and systemic toxoplasmosis reveals a predominance of Toxoplasma gondii type II.

    Science.gov (United States)

    Herrmann, Daland C; Maksimov, Pavlo; Hotop, Andrea; Groß, Uwe; Däubener, Walter; Liesenfeld, Oliver; Pleyer, Uwe; Conraths, Franz J; Schares, Gereon

    2014-10-01

    Toxoplasmosis is an important zoonosis transmitted from animals to humans world-wide. In order to determine Toxoplasma gondii genotypes in individuals living in Germany and to compare findings with those in animals, we analysed nine independent and unlinked genetic markers (nSAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico) by PCR-RFLP in 83 archived T. gondii-positive DNA samples from patients with ocular toxoplasmosis (n=35), toxoplasmic encephalitis (n=32), systemic toxoplasmosis after bone-marrow transplantation (n=15) and congenital toxoplasmosis (n=1). In 46 of these 83 samples the presence of T. gondii DNA was confirmed by conventional end-point PCR. Among these, 17 T. gondii-positive samples were typed at all nine loci. The majority (15/17, 88.2%) of these samples were of T. gondii type II (i.e., including both, the Apico type II and Apico type I variants). In addition, in one sample a T. gondii type II/type III allele combination and in another sample a T. gondii genotype displaying type III alleles at all markers was observed. In the remaining 11 samples, in which T. gondii could only be partially typed, exclusively type II (n=10) or type III (n=1) alleles were observed. Results of the present study suggest that the majority of patients in Germany are infected with type II T. gondii regardless of the clinical manifestation of toxoplasmosis. This finding is in accord with the predominance of type II T. gondii in oocysts isolated from cats and in tissues of other intermediate hosts in Germany. Copyright © 2014 Elsevier GmbH. All rights reserved.

  3. Improving ambulatory saliva-sampling compliance in pregnant women: a randomized controlled study.

    Directory of Open Access Journals (Sweden)

    Julian Moeller

    Full Text Available OBJECTIVE: Noncompliance with scheduled ambulatory saliva sampling is common and has been associated with biased cortisol estimates in nonpregnant subjects. This study is the first to investigate in pregnant women strategies to improve ambulatory saliva-sampling compliance, and the association between sampling noncompliance and saliva cortisol estimates. METHODS: We instructed 64 pregnant women to collect eight scheduled saliva samples on two consecutive days each. Objective compliance with scheduled sampling times was assessed with a Medication Event Monitoring System and self-reported compliance with a paper-and-pencil diary. In a randomized controlled study, we estimated whether a disclosure intervention (informing women about objective compliance monitoring and a reminder intervention (use of acoustical reminders improved compliance. A mixed model analysis was used to estimate associations between women's objective compliance and their diurnal cortisol profiles, and between deviation from scheduled sampling and the cortisol concentration measured in the related sample. RESULTS: Self-reported compliance with a saliva-sampling protocol was 91%, and objective compliance was 70%. The disclosure intervention was associated with improved objective compliance (informed: 81%, noninformed: 60%, F(1,60  = 17.64, p<0.001, but not the reminder intervention (reminders: 68%, without reminders: 72%, F(1,60 = 0.78, p = 0.379. Furthermore, a woman's increased objective compliance was associated with a higher diurnal cortisol profile, F(2,64  = 8.22, p<0.001. Altered cortisol levels were observed in less objective compliant samples, F(1,705  = 7.38, p = 0.007, with delayed sampling associated with lower cortisol levels. CONCLUSIONS: The results suggest that in pregnant women, objective noncompliance with scheduled ambulatory saliva sampling is common and is associated with biased cortisol estimates. To improve sampling compliance, results suggest

  4. Paleomagnetic Studies of Returned Samples from Mars

    Science.gov (United States)

    Weiss, B. P.; Beaty, D. W.; McSween, H. Y.; Carrier, B. L.; Czaja, A. D.; Goreva, Y. S.; Hausrath, E.; Herd, C. D. K.; Humayun, M.; McCubbin, F. M.; McLennan, S. M.; Pratt, L. M.; Sephton, M. A.; Steele, A.

    2018-04-01

    Magnetic measurements of returned samples could transform our understanding of the martian dynamo and its connection to climatic and planetary thermal evolution and provide powerful constraints on the preservation state of sample biosignatures.

  5. A Mixed Methods Sampling Methodology for a Multisite Case Study

    Science.gov (United States)

    Sharp, Julia L.; Mobley, Catherine; Hammond, Cathy; Withington, Cairen; Drew, Sam; Stringfield, Sam; Stipanovic, Natalie

    2012-01-01

    The flexibility of mixed methods research strategies makes such approaches especially suitable for multisite case studies. Yet the utilization of mixed methods to select sites for these studies is rarely reported. The authors describe their pragmatic mixed methods approach to select a sample for their multisite mixed methods case study of a…

  6. Sampling design for the Study of Cardiovascular Risks in Adolescents (ERICA

    Directory of Open Access Journals (Sweden)

    Mauricio Teixeira Leite de Vasconcellos

    2015-05-01

    Full Text Available The Study of Cardiovascular Risk in Adolescents (ERICA aims to estimate the prevalence of cardiovascular risk factors and metabolic syndrome in adolescents (12-17 years enrolled in public and private schools of the 273 municipalities with over 100,000 inhabitants in Brazil. The study population was stratified into 32 geographical strata (27 capitals and five sets with other municipalities in each macro-region of the country and a sample of 1,251 schools was selected with probability proportional to size. In each school three combinations of shift (morning and afternoon and grade were selected, and within each of these combinations, one class was selected. All eligible students in the selected classes were included in the study. The design sampling weights were calculated by the product of the reciprocals of the inclusion probabilities in each sampling stage, and were later calibrated considering the projections of the numbers of adolescents enrolled in schools located in the geographical strata by sex and age.

  7. Approach-Induced Biases in Human Information Sampling.

    Directory of Open Access Journals (Sweden)

    Laurence T Hunt

    2016-11-01

    Full Text Available Information sampling is often biased towards seeking evidence that confirms one's prior beliefs. Despite such biases being a pervasive feature of human behavior, their underlying causes remain unclear. Many accounts of these biases appeal to limitations of human hypothesis testing and cognition, de facto evoking notions of bounded rationality, but neglect more basic aspects of behavioral control. Here, we investigated a potential role for Pavlovian approach in biasing which information humans will choose to sample. We collected a large novel dataset from 32,445 human subjects, making over 3 million decisions, who played a gambling task designed to measure the latent causes and extent of information-sampling biases. We identified three novel approach-related biases, formalized by comparing subject behavior to a dynamic programming model of optimal information gathering. These biases reflected the amount of information sampled ("positive evidence approach", the selection of which information to sample ("sampling the favorite", and the interaction between information sampling and subsequent choices ("rejecting unsampled options". The prevalence of all three biases was related to a Pavlovian approach-avoid parameter quantified within an entirely independent economic decision task. Our large dataset also revealed that individual differences in the amount of information gathered are a stable trait across multiple gameplays and can be related to demographic measures, including age and educational attainment. As well as revealing limitations in cognitive processing, our findings suggest information sampling biases reflect the expression of primitive, yet potentially ecologically adaptive, behavioral repertoires. One such behavior is sampling from options that will eventually be chosen, even when other sources of information are more pertinent for guiding future action.

  8. Prevalence of Methicillin-Resistant Staphylococcus aureus from Equine Nasopharyngeal and Guttural Pouch Wash Samples.

    Science.gov (United States)

    Boyle, A G; Rankin, S C; Duffee, L A; Morris, D

    2017-09-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is recognized as a cause of nosocomial infections in both human and veterinary medicine. Studies that examine the nasopharynx and guttural pouches of the horse as carriage sites for MRSA have not been reported. MRSA colonizes the nasopharynx and guttural pouch of horses. To determine the prevalence of MRSA in equine nasopharyngeal wash (NPW) and guttural pouch lavage (GPL) samples in a field population of horses. One hundred seventy-eight samples (123 NPW and 55 GPL) from 108 horses. Prospective study. Samples were collected from a convenience population of clinically ill horses with suspected Streptococcus equi subsp. equi (S. equi) infection, horses convalescing from a known S. equi infection, and asymptomatic horses undergoing S. equi screening. Samples were submitted for S. aureus aerobic bacterial culture with mannitol salt broth and two selective agars (cefoxitin CHROMagar as the PBP2a inducer and mannitol salt agar with oxacillin). Biochemical identification of Staphylococcus species and pulsed-field gel electrophoresis (PFGE), to determine clonal relationships between isolates, were performed. Methicillin-resistant Staphylococcus (MRS) was isolated from the nasopharynx of 7/108 (4%) horses. Three horses had MRSA (2.7%), and 4 had MR-Staphylococcus pseudintermedius (MRSP). MRSA was isolated from horses on the same farm. PFGE revealed the 3 MRSA as USA 500 strains. Sampling the nasopharynx and guttural pouch of community-based horses revealed a similarly low prevalence rate of MRSA as other studies sampling the nares of community-based horses. More study is required to determine the need for sampling multiple anatomic sites when screening horses for MRSA. Copyright © 2017 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

  9. Effects of sampling methods on the quantity and quality of dissolved organic matter in sediment pore waters as revealed by absorption and fluorescence spectroscopy.

    Science.gov (United States)

    Chen, Meilian; Lee, Jong-Hyeon; Hur, Jin

    2015-10-01

    Despite literature evidence suggesting the importance of sampling methods on the properties of sediment pore waters, their effects on the dissolved organic matter (PW-DOM) have been unexplored to date. Here, we compared the effects of two commonly used sampling methods (i.e., centrifuge and Rhizon sampler) on the characteristics of PW-DOM for the first time. The bulk dissolved organic carbon (DOC), ultraviolet-visible (UV-Vis) absorption, and excitation-emission matrixes coupled with parallel factor analysis (EEM-PARAFAC) of the PW-DOM samples were compared for the two sampling methods with the sediments from minimal to severely contaminated sites. The centrifuged samples were found to have higher average values of DOC, UV absorption, and protein-like EEM-PARAFAC components. The samples collected with the Rhizon sampler, however, exhibited generally more humified characteristics than the centrifuged ones, implying a preferential collection of PW-DOM with respect to the sampling methods. Furthermore, the differences between the two sampling methods seem more pronounced in relatively more polluted sites. Our observations were possibly explained by either the filtration effect resulting from the smaller pore size of the Rhizon sampler or the desorption of DOM molecules loosely bound to minerals during centrifugation, or both. Our study suggests that consistent use of one sampling method is crucial for PW-DOM studies and also that caution should be taken in the comparison of data collected with different sampling methods.

  10. The Relationship between Parenting Styles and Creativity in a Sample of Jamaican Children

    Science.gov (United States)

    Fearon, Danielle D.; Copeland, Daelynn; Saxon, Terrill F.

    2013-01-01

    The purpose of this study was to examine the relationship between parenting styles and creativity among a sample of Jamaican students and their parents. A total of 54 parents and 66 students participated in the study. Results revealed that the authoritarian style of parenting is the most salient predictor of creativity in children and that this…

  11. Bayesian sample size determination for cost-effectiveness studies with censored data.

    Directory of Open Access Journals (Sweden)

    Daniel P Beavers

    Full Text Available Cost-effectiveness models are commonly utilized to determine the combined clinical and economic impact of one treatment compared to another. However, most methods for sample size determination of cost-effectiveness studies assume fully observed costs and effectiveness outcomes, which presents challenges for survival-based studies in which censoring exists. We propose a Bayesian method for the design and analysis of cost-effectiveness data in which costs and effectiveness may be censored, and the sample size is approximated for both power and assurance. We explore two parametric models and demonstrate the flexibility of the approach to accommodate a variety of modifications to study assumptions.

  12. Surface studies of plasma processed Nb samples

    International Nuclear Information System (INIS)

    Tyagi, Puneet V.; Doleans, Marc; Hannah, Brian S.; Afanador, Ralph; Stewart, Stephen; Mammosser, John; Howell, Matthew P; Saunders, Jeffrey W; Degraff, Brian D; Kim, Sang-Ho

    2015-01-01

    Contaminants present at top surface of superconducting radio frequency (SRF) cavities can act as field emitters and restrict the cavity accelerating gradient. A room temperature in-situ plasma processing technology for SRF cavities aiming to clean hydrocarbons from inner surface of cavities has been recently developed at the Spallation Neutron Source (SNS). Surface studies of the plasma-processed Nb samples by Secondary ion mass spectrometry (SIMS) and Scanning Kelvin Probe (SKP) showed that the NeO_2 plasma processing is very effective to remove carbonaceous contaminants from top surface and improves the surface work function by 0.5 to 1.0 eV.

  13. Novel genotype of Ehrlichia canis detected in samples of human blood bank donors in Costa Rica.

    Science.gov (United States)

    Bouza-Mora, Laura; Dolz, Gaby; Solórzano-Morales, Antony; Romero-Zuñiga, Juan José; Salazar-Sánchez, Lizbeth; Labruna, Marcelo B; Aguiar, Daniel M

    2017-01-01

    This study focuses on the detection and identification of DNA and antibodies to Ehrlichia spp. in samples of blood bank donors in Costa Rica using molecular and serological techniques. Presence of Ehrlichia canis was determined in 10 (3.6%) out of 280 blood samples using polymerase chain reaction (PCR) targeting the ehrlichial dsb conserved gene. Analysis of the ehrlichial trp36 polymorphic gene in these 10 samples revealed substantial polymorphism among the E. canis genotypes, including divergent tandem repeat sequences. Nucleotide sequences of dsb and trp36 amplicons revealed a novel genotype of E. canis in blood bank donors from Costa Rica. Indirect immunofluorescence assay (IFA) detected antibodies in 35 (35%) of 100 serum samples evaluated. Thirty samples showed low endpoint titers (64-256) to E. canis, whereas five sera yielded high endpoint titers (1024-8192); these five samples were also E. canis-PCR positive. These findings represent the first report of the presence of E. canis in humans in Central America. Copyright © 2016 Elsevier GmbH. All rights reserved.

  14. Municipal solid waste composition: Sampling methodology, statistical analyses, and case study evaluation

    International Nuclear Information System (INIS)

    Edjabou, Maklawe Essonanawe; Jensen, Morten Bang; Götze, Ramona; Pivnenko, Kostyantyn; Petersen, Claus; Scheutz, Charlotte; Astrup, Thomas Fruergaard

    2015-01-01

    Highlights: • Tiered approach to waste sorting ensures flexibility and facilitates comparison of solid waste composition data. • Food and miscellaneous wastes are the main fractions contributing to the residual household waste. • Separation of food packaging from food leftovers during sorting is not critical for determination of the solid waste composition. - Abstract: Sound waste management and optimisation of resource recovery require reliable data on solid waste generation and composition. In the absence of standardised and commonly accepted waste characterisation methodologies, various approaches have been reported in literature. This limits both comparability and applicability of the results. In this study, a waste sampling and sorting methodology for efficient and statistically robust characterisation of solid waste was introduced. The methodology was applied to residual waste collected from 1442 households distributed among 10 individual sub-areas in three Danish municipalities (both single and multi-family house areas). In total 17 tonnes of waste were sorted into 10–50 waste fractions, organised according to a three-level (tiered approach) facilitating comparison of the waste data between individual sub-areas with different fractionation (waste from one municipality was sorted at “Level III”, e.g. detailed, while the two others were sorted only at “Level I”). The results showed that residual household waste mainly contained food waste (42 ± 5%, mass per wet basis) and miscellaneous combustibles (18 ± 3%, mass per wet basis). The residual household waste generation rate in the study areas was 3–4 kg per person per week. Statistical analyses revealed that the waste composition was independent of variations in the waste generation rate. Both, waste composition and waste generation rates were statistically similar for each of the three municipalities. While the waste generation rates were similar for each of the two housing types (single

  15. Municipal solid waste composition: Sampling methodology, statistical analyses, and case study evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Edjabou, Maklawe Essonanawe, E-mail: vine@env.dtu.dk [Department of Environmental Engineering, Technical University of Denmark, 2800 Kgs. Lyngby (Denmark); Jensen, Morten Bang; Götze, Ramona; Pivnenko, Kostyantyn [Department of Environmental Engineering, Technical University of Denmark, 2800 Kgs. Lyngby (Denmark); Petersen, Claus [Econet AS, Omøgade 8, 2.sal, 2100 Copenhagen (Denmark); Scheutz, Charlotte; Astrup, Thomas Fruergaard [Department of Environmental Engineering, Technical University of Denmark, 2800 Kgs. Lyngby (Denmark)

    2015-02-15

    Highlights: • Tiered approach to waste sorting ensures flexibility and facilitates comparison of solid waste composition data. • Food and miscellaneous wastes are the main fractions contributing to the residual household waste. • Separation of food packaging from food leftovers during sorting is not critical for determination of the solid waste composition. - Abstract: Sound waste management and optimisation of resource recovery require reliable data on solid waste generation and composition. In the absence of standardised and commonly accepted waste characterisation methodologies, various approaches have been reported in literature. This limits both comparability and applicability of the results. In this study, a waste sampling and sorting methodology for efficient and statistically robust characterisation of solid waste was introduced. The methodology was applied to residual waste collected from 1442 households distributed among 10 individual sub-areas in three Danish municipalities (both single and multi-family house areas). In total 17 tonnes of waste were sorted into 10–50 waste fractions, organised according to a three-level (tiered approach) facilitating comparison of the waste data between individual sub-areas with different fractionation (waste from one municipality was sorted at “Level III”, e.g. detailed, while the two others were sorted only at “Level I”). The results showed that residual household waste mainly contained food waste (42 ± 5%, mass per wet basis) and miscellaneous combustibles (18 ± 3%, mass per wet basis). The residual household waste generation rate in the study areas was 3–4 kg per person per week. Statistical analyses revealed that the waste composition was independent of variations in the waste generation rate. Both, waste composition and waste generation rates were statistically similar for each of the three municipalities. While the waste generation rates were similar for each of the two housing types (single

  16. How much will afforestation of former cropland influence soil C stocks? A synthesis of paired sampling, chronosequence sampling and repeated sampling studies

    Science.gov (United States)

    Vesterdal, Lars; Hansen, K.; Stupak, I.; Don, Axel; Poeplau, C.; Leifeld, Jens; van Wesemael, Bas

    2010-05-01

    The need for documentation of land-use change effects on soil C is high on the agenda in most signatory countries to the Kyoto Protocol. Large land areas in Europe have experienced land-use change from cropland to forest since 1990 by direct afforestation as well as abandonment and regrowth of marginally productive cropland. Soil C dynamics following land-use change remain highly uncertain due to a limited number of available studies and due to influence of interacting factors such as land use history, soil type, and climate. Common approaches for estimation of potential soil C changes following land-use change are i) paired sampling of plots with a long legacy of different land uses, ii) chronosequence studies of land-use change, and lastly iii) repeated sampling of plots subject to changed land use. This paper will synthesize the quantitative effects of cropland afforestation on soil C sequestration based on all three approaches and will report on related work within Cost 639. Paired plots of forest and cropland were used to study the general differences between soil C stocks in the two land uses. At 27 sites in Denmark distributed among different regions and soil types forest floor and mineral soil were sampled in and around soil pits. Soil C stocks were higher in forest than cropland (mean difference 22 Mg C ha-1 to 1 m depth). This difference was caused solely by the presence of a forest floor in forests; mineral soil C stocks were similar (108 vs. 109 Mg C ha-1) in the two land uses regardless of soil type and the soil layers considered. The chronosequence approach was employed in the AFFOREST project for evaluation of C sequestration in biomass and soils following afforestation of cropland. Two oak (Quercus robur) and four Norway spruce (Picea abies) afforestation chronosequences (age range 1 to 90 years) were studied in Denmark, Sweden and the Netherlands. Forest floor and mineral soil (0-25 cm) C contents were as a minimum unchanged and in most cases there

  17. Effects of Blood Sample Collection Pre- and Post- Slaughter, Edta ...

    African Journals Online (AJOL)

    The samples were immediately subjected to Wet mount (WM), Haemotocrit centrifugation test (HCT) and Thin smear (TS) tests. The results revealed that, of the 100 samples examined, 19 (19%) were positive for the presence of Microfilaria spp while 6(6%) yielded Trypanosome spp. Of the 19 samples detected having ...

  18. Bovine liver sample preparation and micro-homogeneity study for Cu and Zn determination by solid sampling electrothermal atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Nomura, Cassiana S.; Silva, Cintia S.; Nogueira, Ana R.A.; Oliveira, Pedro V.

    2005-01-01

    This work describes a systematic study for the bovine liver sample preparation for Cu and Zn determination by solid sampling electrothermal atomic absorption spectrometry. The main parameters investigated were sample drying, grinding process, particle size, sample size, microsample homogeneity, and their relationship with the precision and accuracy of the method. A bovine liver sample was prepared using different drying procedures: (1) freeze drying, and (2) drying in a household microwave oven followed by drying in a stove at 60 deg. C until constant mass. Ball and cryogenic mills were used for grinding. Less sensitive wavelengths for Cu (216.5 nm) and Zn (307.6 nm), and Zeeman-based three-field background correction for Cu were used to diminish the sensitivities. The pyrolysis and atomization temperatures adopted were 1000 deg. C and 2300 deg. C for Cu, and 700 deg. C and 1700 deg. C for Zn, respectively. For both elements, it was possible to calibrate the spectrometer with aqueous solutions. The use of 250 μg of W + 200 μg of Rh as permanent chemical modifier was imperative for Zn. Under these conditions, the characteristic mass and detection limit were 1.4 ng and 1.6 ng for Cu, and 2.8 ng and 1.3 ng for Zn, respectively. The results showed good agreement (95% confidence level) for homogeneity of the entire material (> 200 mg) when the sample was dried in microwave/stove and ground in a cryogenic mill. The microsample homogeneity study showed that Zn is more dependent on the sample pretreatment than Cu. The bovine liver sample prepared in microwave/stove and ground in a cryogenic mill presented results with the lowest relative standard deviation for Cu than Zn. Good accuracy and precision were observed for bovine liver masses higher than 40 μg for Cu and 30 μg for Zn. The concentrations of Cu and Zn in the prepared bovine liver sample were 223 mg kg - 1 and 128 mg kg - 1 , respectively. The relative standard deviations were lower than 6% (n = 5). The

  19. Systematic studies of small scintillators for new sampling calorimeter

    Indian Academy of Sciences (India)

    A new sampling calorimeter using very thin scintillators and the multi-pixel photon counter (MPPC) has been proposed to produce better position resolution for the international linear collider (ILC) experiment. As part of this R & D study, small plastic scintillators of different sizes, thickness and wrapping reflectors are ...

  20. What is the optimum sample size for the study of peatland testate amoeba assemblages?

    Science.gov (United States)

    Mazei, Yuri A; Tsyganov, Andrey N; Esaulov, Anton S; Tychkov, Alexander Yu; Payne, Richard J

    2017-10-01

    Testate amoebae are widely used in ecological and palaeoecological studies of peatlands, particularly as indicators of surface wetness. To ensure data are robust and comparable it is important to consider methodological factors which may affect results. One significant question which has not been directly addressed in previous studies is how sample size (expressed here as number of Sphagnum stems) affects data quality. In three contrasting locations in a Russian peatland we extracted samples of differing size, analysed testate amoebae and calculated a number of widely-used indices: species richness, Simpson diversity, compositional dissimilarity from the largest sample and transfer function predictions of water table depth. We found that there was a trend for larger samples to contain more species across the range of commonly-used sample sizes in ecological studies. Smaller samples sometimes failed to produce counts of testate amoebae often considered minimally adequate. It seems likely that analyses based on samples of different sizes may not produce consistent data. Decisions about sample size need to reflect trade-offs between logistics, data quality, spatial resolution and the disturbance involved in sample extraction. For most common ecological applications we suggest that samples of more than eight Sphagnum stems are likely to be desirable. Copyright © 2017 Elsevier GmbH. All rights reserved.

  1. Studies on radioactivities of dust samples in the air at high altitudes

    International Nuclear Information System (INIS)

    Kohara, Eri; Muronoi, Naohiro

    2015-01-01

    The radioactivity concentrations of airborne dust samples were studied. The samples had been collected at high altitude by the Japan Air Self-Defense Force from April 2013 to March 2014. The obtained data were used for gross beta radioactivity analysis and gamma nuclide analysis. It is shown that cesium 137 was mainly detected at the 10 km and 3 km altitude of central area of Japan in several samples. Gaseous radioiodine was not detected in all the samples. Radioactive xenon was detected but the concentration did not show significant difference to the background level. (author)

  2. Microanalysis study of archaeological mural samples containing Maya blue pigment

    International Nuclear Information System (INIS)

    Sanchez del Rio, M.; Martinetto, P.; Somogyi, A.; Reyes-Valerio, C.; Dooryhee, E.; Peltier, N.; Alianelli, L.; Moignard, B.; Pichon, L.; Calligaro, T.; Dran, J.-C.

    2004-01-01

    Elemental analysis by X-ray fluorescence and particle induced X-ray emission is applied to the study of several Mesoamerican mural samples containing blue pigments. The most characteristic blue pigment is Maya blue, a very stable organo-clay complex original from Maya culture and widely used in murals, pottery and sculptures in a vast region of Mesoamerica during the pre-hispanic time (from VIII century) and during the colonization until 1580. The mural samples come from six different archaeological sites (four pre-hispanic and two from XVI century colonial convents). The correlation between the presence of some elements and the pigment colour is discussed. From the comparative study of the elemental concentration, some conclusions are drawn on the nature of the pigments and the technology used

  3. Microanalysis study of archaeological mural samples containing Maya blue pigment

    Science.gov (United States)

    Sánchez del Río, M.; Martinetto, P.; Somogyi, A.; Reyes-Valerio, C.; Dooryhée, E.; Peltier, N.; Alianelli, L.; Moignard, B.; Pichon, L.; Calligaro, T.; Dran, J.-C.

    2004-10-01

    Elemental analysis by X-ray fluorescence and particle induced X-ray emission is applied to the study of several Mesoamerican mural samples containing blue pigments. The most characteristic blue pigment is Maya blue, a very stable organo-clay complex original from Maya culture and widely used in murals, pottery and sculptures in a vast region of Mesoamerica during the pre-hispanic time (from VIII century) and during the colonization until 1580. The mural samples come from six different archaeological sites (four pre-hispanic and two from XVI century colonial convents). The correlation between the presence of some elements and the pigment colour is discussed. From the comparative study of the elemental concentration, some conclusions are drawn on the nature of the pigments and the technology used.

  4. Microanalysis study of archaeological mural samples containing Maya blue pigment

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez del Rio, M. [ESRF, BP220, F-38043 Grenoble (France)]. E-mail: srio@esrf.fr; Martinetto, P. [Laboratoire de Cristallographie, CNRS, BP166 F-30842 Grenoble (France); Somogyi, A. [ESRF, BP220, F-38043 Grenoble (France); Reyes-Valerio, C. [INAH, Mexico DF (Mexico); Dooryhee, E. [Laboratoire de Cristallographie, CNRS, BP166 F-30842 Grenoble (France); Peltier, N. [Laboratoire de Cristallographie, CNRS, BP166 F-30842 Grenoble (France); Alianelli, L. [INFM-OGG c/o ESRF, BP220, F-38043 Grenoble Cedex (France); Moignard, B. [C2RMF, 6 Rue des Pyramides, F-75041 Paris Cedex 01 (France); Pichon, L. [C2RMF, 6 Rue des Pyramides, F-75041 Paris Cedex 01 (France); Calligaro, T. [C2RMF, 6 Rue des Pyramides, F-75041 Paris Cedex 01 (France); Dran, J.-C. [C2RMF, 6 Rue des Pyramides, F-75041 Paris Cedex 01 (France)

    2004-10-08

    Elemental analysis by X-ray fluorescence and particle induced X-ray emission is applied to the study of several Mesoamerican mural samples containing blue pigments. The most characteristic blue pigment is Maya blue, a very stable organo-clay complex original from Maya culture and widely used in murals, pottery and sculptures in a vast region of Mesoamerica during the pre-hispanic time (from VIII century) and during the colonization until 1580. The mural samples come from six different archaeological sites (four pre-hispanic and two from XVI century colonial convents). The correlation between the presence of some elements and the pigment colour is discussed. From the comparative study of the elemental concentration, some conclusions are drawn on the nature of the pigments and the technology used.

  5. CNV-association meta-analysis in 191,161 European adults reveals new loci associated with anthropometric traits

    NARCIS (Netherlands)

    Macé, Aurélien; Tuke, Marcus A; Deelen, Patrick; Kristiansson, Kati; Mattsson, Hannele; Nõukas, Margit; Sapkota, Yadav; Schick, Ursula; Porcu, Eleonora; Rüeger, Sina; McDaid, Aaron F; Porteous, David; Winkler, Thomas W; Salvi, Erika; Shrine, Nick; Liu, Xueping; Ang, Wei Q; Zhang, Weihua; Feitosa, Mary F; Venturini, Cristina; van der Most, Peter J; Rosengren, Anders; Wood, Andrew R; Beaumont, Robin N; Jones, Samuel E; Ruth, Katherine S; Yaghootkar, Hanieh; Tyrrell, Jessica; Havulinna, Aki S; Boers, Harmen; Mägi, Reedik; Kriebel, Jennifer; Müller-Nurasyid, Martina; Perola, Markus; Nieminen, Markku; Lokki, Marja-Liisa; Kähönen, Mika; Viikari, Jorma S; Geller, Frank; Lahti, Jari; Palotie, Aarno; Koponen, Päivikki; Lundqvist, Annamari; Rissanen, Harri; Bottinger, Erwin P; Afaq, Saima; Wojczynski, Mary K; Lenzini, Petra; Nolte, Ilja M; Sparsø, Thomas; Schupf, Nicole; Christensen, Kaare; Perls, Thomas T; Newman, Anne B; Werge, Thomas; Snieder, Harold; Spector, Timothy D; Chambers, John C; Koskinen, Seppo; Melbye, Mads; Raitakari, Olli T; Lehtimäki, Terho; Tobin, Martin D; Wain, Louise V; Sinisalo, Juha; Peters, Annette; Meitinger, Thomas; Martin, Nicholas G; Wray, Naomi R; Montgomery, Grant W; Medland, Sarah E; Swertz, Morris A; Vartiainen, Erkki; Borodulin, Katja; Männistö, Satu; Murray, Anna; Bochud, Murielle; Jacquemont, Sébastien; Rivadeneira, Fernando; Hansen, Thomas F; Oldehinkel, Albertine J; Mangino, Massimo; Province, Michael A; Deloukas, Panos; Kooner, Jaspal S; Freathy, Rachel M; Pennell, Craig; Feenstra, Bjarke; Strachan, David P; Lettre, Guillaume; Hirschhorn, Joel; Cusi, Daniele; Heid, Iris M; Hayward, Caroline; Männik, Katrin; Beckmann, Jacques S; Loos, Ruth J F; Nyholt, Dale R; Metspalu, Andres; Eriksson, Johan G; Weedon, Michael N; Salomaa, Veikko; Franke, Lude; Reymond, Alexandre; Frayling, Timothy M; Kutalik, Zoltán

    2017-01-01

    There are few examples of robust associations between rare copy number variants (CNVs) and complex continuous human traits. Here we present a large-scale CNV association meta-analysis on anthropometric traits in up to 191,161 adult samples from 26 cohorts. The study reveals five CNV associations at

  6. A Study on the Representative Sampling Survey for Radionuclide Analysis of RI Waste

    Energy Technology Data Exchange (ETDEWEB)

    Jee, K. Y. [KAERI, Daejeon (Korea, Republic of); Kim, Juyoul; Jung, Gunhyo [FNC Tech. Co., Daejeon (Korea, Republic of)

    2007-07-15

    We developed a quantitative method for attaining a representative sample during sampling survey of RI waste. Considering a source, process, and type of RI waste, the method computes the number of sample, confidence interval, variance, and coefficient of variance. We also systematize the method of sampling survey logically and quantitatively. The result of this study can be applied to sampling survey of low- and intermediate-level waste generated from nuclear power plant during the transfer process to disposal facility.

  7. Ferricyanide-based analysis of aqueous lignin suspension revealed sequestration of water-soluble lignin moieties

    OpenAIRE

    Joshua, CJ; Simmons, BA; Singer, SW

    2016-01-01

    © 2016 The Royal Society of Chemistry. This study describes the application of a ferricyanide-based assay as a simple and inexpensive assay for rapid analysis of aqueous lignin samples. The assay measures the formation of Prussian blue from the redox reaction between a mixture of potassium ferricyanide and ferric chloride, and phenolic hydroxyl groups of lignin or lignin-derived phenolic moieties. This study revealed that soluble lignin moieties exhibited stronger ferricyanide reactivity than...

  8. Successful Sampling Strategy Advances Laboratory Studies of NMR Logging in Unconsolidated Aquifers

    Science.gov (United States)

    Behroozmand, Ahmad A.; Knight, Rosemary; Müller-Petke, Mike; Auken, Esben; Barfod, Adrian A. S.; Ferré, Ty P. A.; Vilhelmsen, Troels N.; Johnson, Carole D.; Christiansen, Anders V.

    2017-11-01

    The nuclear magnetic resonance (NMR) technique has become popular in groundwater studies because it responds directly to the presence and mobility of water in a porous medium. There is a need to conduct laboratory experiments to aid in the development of NMR hydraulic conductivity models, as is typically done in the petroleum industry. However, the challenge has been obtaining high-quality laboratory samples from unconsolidated aquifers. At a study site in Denmark, we employed sonic drilling, which minimizes the disturbance of the surrounding material, and extracted twelve 7.6 cm diameter samples for laboratory measurements. We present a detailed comparison of the acquired laboratory and logging NMR data. The agreement observed between the laboratory and logging data suggests that the methodologies proposed in this study provide good conditions for studying NMR measurements of unconsolidated near-surface aquifers. Finally, we show how laboratory sample size and condition impact the NMR measurements.

  9. Sampling system for a boiling reactor NPP

    International Nuclear Information System (INIS)

    Zabelin, A.I.; Yakovleva, E.D.; Solov'ev, Yu.A.

    1976-01-01

    Investigations and pilot running of the nuclear power plant with a VK-50 boiling reactor reveal the necessity of normalizing the design system of water sampling and of mandatory replacement of the needle-type throttle device by a helical one. A method for designing a helical throttle device has been worked out. The quantitative characteristics of depositions of corrosion products along the line of reactor water sampling are presented. Recommendations are given on the organizaton of the sampling system of a nuclear power plant with BWR type reactors

  10. Non-destructive sampling of ancient insect DNA

    DEFF Research Database (Denmark)

    Thomsen, Philip Francis; Elias, Scott; Gilbert, Tom

    2009-01-01

    BACKGROUND: A major challenge for ancient DNA (aDNA) studies on insect remains is that sampling procedures involve at least partial destruction of the specimens. A recent extraction protocol reveals the possibility of obtaining DNA from past insect remains without causing visual morphological...... of 77-204 base pairs (-bp) in size using species-specific and general insect primers. CONCLUSION/SIGNIFICANCE: The applied non-destructive DNA extraction method shows promising potential on insect museum specimens of historical age as far back as AD 1820, but less so on the ancient permafrost......-preserved insect fossil remains tested, where DNA was obtained from samples up to ca. 26,000 years old. The non-frozen sediment DNA approach appears to have great potential for recording the former presence of insect taxa not normally preserved as macrofossils and opens new frontiers in research on ancient...

  11. Trace element studies in bioenvironmental samples using 3-MeV protons

    International Nuclear Information System (INIS)

    Walter, R.L.; Willis, R.D.; Gutknecht, W.F.

    1974-01-01

    Trace metal compositions of a wide range of biological, environmental, medical and clinical samples were investigated using proton-induced x-ray emission analysis (PIXEA). The x-rays were detected with a Si(Li) detector and spectra from over 3000 irradiations have been recorded on magnetic tape. The chi 2 fitting code TRACE developed at our laboratory was used in a semi-automatic mode to extract abundances of elements from S to Cd. Various methods of overcoming analytical problems and specimen preparation difficulties are reported. Results from some samples for typical studies are illustrated along with the reasons for interest in the sample types

  12. Analytical study on the determination of boron in environmental water samples

    International Nuclear Information System (INIS)

    Lopez, F.J.; Gimenez, E.; Hernandez, F.

    1993-01-01

    An analytical study on the determination of boron in environmental water samples was carried out. The curcumin and carmine standard methods were compared with the most recent Azomethine-H method in order to evaluate their analytical characteristics and feasibility for the analysis of boron in water samples. Analyses of synthetic water, ground water, sea water and waste water samples were carried out and a statistical evaluation of the results was made. The Azomethine-H method was found to be the most sensitive (detection limit 0.02 mg l -1 ) and selective (no interference of commonly occurring ions in water was observed), showing also the best precision (relative standard deviation lower than 4%). Moreover, it gave good results for all types of samples analyzed. The accuracy of this method was tested by the addition of known amounts of standard solutions to different types of water samples. The slopes of standard additions and direct calibration graphs were similar and recoveries of added boron ranged from 99 to 107%. (orig.)

  13. Electron Spin Resonance (ESR) studies of returned comet nucleus samples

    International Nuclear Information System (INIS)

    Tsay, Fundow; Kim, S.S.; Liang, R.H.

    1989-01-01

    The most important objective of the Comet Nucleus Sample Returm Mission is to return samples which could reflect formation conditions and evolutionary processes in the early solar nebula. It is expected that the returned samples will consist of fine-grained silicate materials mixed with ices composed of simple molecules such as H 2 O, NH 3 , CH 4 as well as organics and/or more complex compounds. Because of the exposure to ionizing radiation from cosmic-ray, gamma-ray, and solar wind protons at low temperature, free radicals are expected to be formed and trapped in the solid ice matrices. The kind of trapped radical species together with their concentration and thermal stability can be used as a dosimeter as well as a geothermometer to determine thermal and radiation histories as well as outgassing and other possible alternation effects since the nucleus material was formed. Since free radicals that are known to contain unpaired electrons are all paramagnetic in nature, they can be readily detected and characterized in their native form by the Electron Spin Resonance (ESR) method. In fact, ESR has been shown to be a non-destructive, highly sensitive tool for the detection and characterization of paramagnetic, ferromagnetic, and radiation damage centers in terrestrial and extraterrestrial geological samples. The potential use of ESR as an effective method in the study of returned comet nucleus samples, in particular, in the analysis of fine-grained solid state icy samples is discussed

  14. The effects of parameter estimation on minimizing the in-control average sample size for the double sampling X bar chart

    Directory of Open Access Journals (Sweden)

    Michael B.C. Khoo

    2013-11-01

    Full Text Available The double sampling (DS X bar chart, one of the most widely-used charting methods, is superior for detecting small and moderate shifts in the process mean. In a right skewed run length distribution, the median run length (MRL provides a more credible representation of the central tendency than the average run length (ARL, as the mean is greater than the median. In this paper, therefore, MRL is used as the performance criterion instead of the traditional ARL. Generally, the performance of the DS X bar chart is investigated under the assumption of known process parameters. In practice, these parameters are usually estimated from an in-control reference Phase-I dataset. Since the performance of the DS X bar chart is significantly affected by estimation errors, we study the effects of parameter estimation on the MRL-based DS X bar chart when the in-control average sample size is minimised. This study reveals that more than 80 samples are required for the MRL-based DS X bar chart with estimated parameters to perform more favourably than the corresponding chart with known parameters.

  15. Phylogenetic representativeness: a new method for evaluating taxon sampling in evolutionary studies

    Directory of Open Access Journals (Sweden)

    Passamonti Marco

    2010-04-01

    Full Text Available Abstract Background Taxon sampling is a major concern in phylogenetic studies. Incomplete, biased, or improper taxon sampling can lead to misleading results in reconstructing evolutionary relationships. Several theoretical methods are available to optimize taxon choice in phylogenetic analyses. However, most involve some knowledge about the genetic relationships of the group of interest (i.e., the ingroup, or even a well-established phylogeny itself; these data are not always available in general phylogenetic applications. Results We propose a new method to assess taxon sampling developing Clarke and Warwick statistics. This method aims to measure the "phylogenetic representativeness" of a given sample or set of samples and it is based entirely on the pre-existing available taxonomy of the ingroup, which is commonly known to investigators. Moreover, our method also accounts for instability and discordance in taxonomies. A Python-based script suite, called PhyRe, has been developed to implement all analyses we describe in this paper. Conclusions We show that this method is sensitive and allows direct discrimination between representative and unrepresentative samples. It is also informative about the addition of taxa to improve taxonomic coverage of the ingroup. Provided that the investigators' expertise is mandatory in this field, phylogenetic representativeness makes up an objective touchstone in planning phylogenetic studies.

  16. Astronaut Neil Armstrong studies rock samples during geological field trip

    Science.gov (United States)

    1969-01-01

    Astronaut Neil Armstrong, commander of the Apollo 11 lunar landing mission, studies rock samples during a geological field trip to the Quitman Mountains area near the Fort Quitman ruins in far west Texas.

  17. Evolutionary Meta-Analysis of Association Studies Reveals Ancient Constraints Affecting Disease Marker Discovery

    Science.gov (United States)

    Dudley, Joel T.; Chen, Rong; Sanderford, Maxwell; Butte, Atul J.; Kumar, Sudhir

    2012-01-01

    Genome-wide disease association studies contrast genetic variation between disease cohorts and healthy populations to discover single nucleotide polymorphisms (SNPs) and other genetic markers revealing underlying genetic architectures of human diseases. Despite scores of efforts over the past decade, many reproducible genetic variants that explain substantial proportions of the heritable risk of common human diseases remain undiscovered. We have conducted a multispecies genomic analysis of 5,831 putative human risk variants for more than 230 disease phenotypes reported in 2,021 studies. We find that the current approaches show a propensity for discovering disease-associated SNPs (dSNPs) at conserved genomic positions because the effect size (odds ratio) and allelic P value of genetic association of an SNP relates strongly to the evolutionary conservation of their genomic position. We propose a new measure for ranking SNPs that integrates evolutionary conservation scores and the P value (E-rank). Using published data from a large case-control study, we demonstrate that E-rank method prioritizes SNPs with a greater likelihood of bona fide and reproducible genetic disease associations, many of which may explain greater proportions of genetic variance. Therefore, long-term evolutionary histories of genomic positions offer key practical utility in reassessing data from existing disease association studies, and in the design and analysis of future studies aimed at revealing the genetic basis of common human diseases. PMID:22389448

  18. Risk Factors for Running Away among a General Population Sample of Males and Females

    Science.gov (United States)

    Tyler, Kimberly A.; Hagewen, Kellie J.; Melander, Lisa A.

    2011-01-01

    The present study examines risk factors for running away and homelessness among a sample of more than 7,000 currently housed youth using the National Longitudinal Study of Adolescent Health (Add Health). Structural equation modeling results revealed that those with greater levels of family instability and those who ran away at Wave 2 were…

  19. A comparison of passive and active acoustic sampling for a bat community impacted by White-nose syndrome

    Science.gov (United States)

    Coleman, Laci S.; Ford, W. Mark; Dobony, Christopher A.; Britzke, Eric R.

    2014-01-01

    In the summers of 2011 and 2012, we compared passive and active acoustic sampling for bats at 31 sites at Fort Drum Military Installation, New York. We defined active sampling as acoustic sampling that occurred in 30-min intervals between the hours of sunset and 0200 with a user present to manipulate the directionality of the microphone. We defined passive sampling as acoustic sampling that occurred over a 12-h period (1900–0700 hours) without a user present and with the microphone set in a predetermined direction. We detected seven of the nine possible species at Fort Drum, including the federally endangered Indiana bat Myotis sodalis, the proposed-for-listing northern bat M. septentrionalis, the little brown bat M. lucifugus, and the big brown bat Eptesicus fuscus, which are impacted by white-nose syndrome (WNS); and the eastern red bat Lasiurus borealis, the hoary bat L. cinereus, and the silver-haired bat Lasionycteris noctivagans, which are not known to be impacted by WNS. We did not detect two additional WNS-impacted species known to historically occur in the area: the eastern small-footed bat Myotis leibii and the tri-colored bat Perimyotis subflavus. Single-season occupancy models revealed lower detection probabilities of all detected species using active sampling versus passive sampling. Additionally, overall detection probabilities declined in detected WNS-impacted species between years. A paired t-test of simultaneous sampling on 21 occasions revealed that overall recorded foraging activity per hour was greater using active than passive sampling for big brown bats and greater using passive than active sampling for little brown bats. There was no significant difference in recorded activity between methods for other WNS-impacted species, presumably because these species have been so reduced in number that their “apparency” on the landscape is lower. Finally, a cost analysis of standard passive and active sampling protocols revealed that passive

  20. A review of blood sample handling and pre-processing for metabolomics studies.

    Science.gov (United States)

    Hernandes, Vinicius Veri; Barbas, Coral; Dudzik, Danuta

    2017-09-01

    Metabolomics has been found to be applicable to a wide range of clinical studies, bringing a new era for improving clinical diagnostics, early disease detection, therapy prediction and treatment efficiency monitoring. A major challenge in metabolomics, particularly untargeted studies, is the extremely diverse and complex nature of biological specimens. Despite great advances in the field there still exist fundamental needs for considering pre-analytical variability that can introduce bias to the subsequent analytical process and decrease the reliability of the results and moreover confound final research outcomes. Many researchers are mainly focused on the instrumental aspects of the biomarker discovery process, and sample related variables sometimes seem to be overlooked. To bridge the gap, critical information and standardized protocols regarding experimental design and sample handling and pre-processing are highly desired. Characterization of a range variation among sample collection methods is necessary to prevent results misinterpretation and to ensure that observed differences are not due to an experimental bias caused by inconsistencies in sample processing. Herein, a systematic discussion of pre-analytical variables affecting metabolomics studies based on blood derived samples is performed. Furthermore, we provide a set of recommendations concerning experimental design, collection, pre-processing procedures and storage conditions as a practical review that can guide and serve for the standardization of protocols and reduction of undesirable variation. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Preparation of irritant polymer samples for an in vitro round robin study.

    NARCIS (Netherlands)

    Coleman, Kelly P; Grailer, Thomas P; McNamara, Lori R; Rollins, Beau L; Christiano, Nicholas J; Kandárová, Helena; De Jong, Wim H

    2018-01-01

    A round robin study using reconstructed human epidermis (RhE) tissues was conducted to test medical device polymer extracts for skin irritation potential. Test samples were four irritant and three non-irritant medical device polymers. Five of these polymer samples were developed and two were

  2. Scrupulosity in Islam: a comparison of highly religious Turkish and Canadian samples.

    Science.gov (United States)

    Inozu, Mujgan; Clark, David A; Karanci, A Nuray

    2012-03-01

    Scrupulosity is a form of obsessive-compulsive disorder (OCD) characterized by a tendency to have persistent doubts about God, sin, and the adequacy of one's religious behaviors and devotion. To date, no published studies have compared scrupulosity in high- and low-religious Muslim and Christian samples. In the present study religious school students as well as high- and low-religious university students in Turkey and Canada were compared on the Penn Inventory of Scrupulosity (PIOS), Obsessive Beliefs Questionnaire (OBQ-44), and symptom measures of obssesionality and negative affect. Between-group comparisons revealed that the highly religious Turkish sample scored significantly higher than the highly religious Canadian students on the PIOS Fear of God but not the Fear of Sin subscale. Separate multiple regression analyses revealed that the Clark-Beck Obsessive Compulsive Inventory (CBOCI) Obsessions subscale, OBQ-44 Importance and Control of Thoughts subscale, and guilt were significant unique predictors of PIOS scrupulosity. These findings suggest that subtle differences exist in how scrupulosity is manifested in Islamic and Christian believers. Copyright © 2011. Published by Elsevier Ltd.

  3. New complete sample of identified radio sources. Part 2. Statistical study

    International Nuclear Information System (INIS)

    Soltan, A.

    1978-01-01

    Complete sample of radio sources with known redshifts selected in Paper I is studied. Source counts in the sample and the luminosity - volume test show that both quasars and galaxies are subject to the evolution. Luminosity functions for different ranges of redshifts are obtained. Due to many uncertainties only simplified models of the evolution are tested. Exponential decline of the liminosity with time of all the bright sources is in a good agreement both with the luminosity- volume test and N(S) realtion in the entire range of observed flux densities. It is shown that sources in the sample are randomly distributed in scales greater than about 17 Mpc. (author)

  4. Diagnosing Autism in Adults with Intellectual Disability: Validation of the DiBAS-R in an Independent Sample

    Science.gov (United States)

    Heinrich, Manuel; Böhm, Julia; Sappok, Tanja

    2018-01-01

    The study assessed the diagnostic validity of the diagnostic behavioral assessment for autism spectrum disorders-revised (DiBAS-R; 19-item screening scale based on ratings by caregivers) in a clinical sample of 381 adults with ID. Analysis revealed a sensitivity of 0.82 and a specificity of 0.67 in the overall sample (70.3% agreement). Sensitivity…

  5. Sampling frequency of ciliated protozoan microfauna for seasonal distribution research in marine ecosystems.

    Science.gov (United States)

    Xu, Henglong; Yong, Jiang; Xu, Guangjian

    2015-12-30

    Sampling frequency is important to obtain sufficient information for temporal research of microfauna. To determine an optimal strategy for exploring the seasonal variation in ciliated protozoa, a dataset from the Yellow Sea, northern China was studied. Samples were collected with 24 (biweekly), 12 (monthly), 8 (bimonthly per season) and 4 (seasonally) sampling events. Compared to the 24 samplings (100%), the 12-, 8- and 4-samplings recovered 94%, 94%, and 78% of the total species, respectively. To reveal the seasonal distribution, the 8-sampling regime may result in >75% information of the seasonal variance, while the traditional 4-sampling may only explain sampling frequency, the biotic data showed stronger correlations with seasonal variables (e.g., temperature, salinity) in combination with nutrients. It is suggested that the 8-sampling events per year may be an optimal sampling strategy for ciliated protozoan seasonal research in marine ecosystems. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Genus-Specific Primers for Study of Fusarium Communities in Field Samples

    Science.gov (United States)

    Edel-Hermann, Véronique; Gautheron, Nadine; Durling, Mikael Brandström; Kolseth, Anna-Karin; Steinberg, Christian; Persson, Paula; Friberg, Hanna

    2015-01-01

    Fusarium is a large and diverse genus of fungi of great agricultural and economic importance, containing many plant pathogens and mycotoxin producers. To date, high-throughput sequencing of Fusarium communities has been limited by the lack of genus-specific primers targeting regions with high discriminatory power at the species level. In the present study, we evaluated two Fusarium-specific primer pairs targeting translation elongation factor 1 (TEF1). We also present the new primer pair Fa+7/Ra+6. Mock Fusarium communities reflecting phylogenetic diversity were used to evaluate the accuracy of the primers in reflecting the relative abundance of the species. TEF1 amplicons were subjected to 454 high-throughput sequencing to characterize Fusarium communities. Field samples from soil and wheat kernels were included to test the method on more-complex material. For kernel samples, a single PCR was sufficient, while for soil samples, nested PCR was necessary. The newly developed primer pairs Fa+7/Ra+6 and Fa/Ra accurately reflected Fusarium species composition in mock DNA communities. In field samples, 47 Fusarium operational taxonomic units were identified, with the highest Fusarium diversity in soil. The Fusarium community in soil was dominated by members of the Fusarium incarnatum-Fusarium equiseti species complex, contradicting findings in previous studies. The method was successfully applied to analyze Fusarium communities in soil and plant material and can facilitate further studies of Fusarium ecology. PMID:26519387

  7. Prenatal cytogenetic diagnosis after transabdominal chorionic villus sampling in the first trimester

    DEFF Research Database (Denmark)

    Therkelsen, A J; Jensen, P K; Hertz, Jens Michael

    1988-01-01

    First trimester prenatal cytogenetic diagnosis was attempted in 350 pregnancies after transabdominal chorionic villus sampling. The cytogenetic investigation was performed using both a short-term method (24 h incubation) and cell culture. Adequate samples were obtained in 99.1 per cent and in all...... of 181 cases where the 24 h incubation revealed a male karyotype. Studies of culture morphology showed that colonies of convoluted cells may serve as a marker for contamination with maternal cells in culture. For the present, we recommend using a short-term method as well as cell culture for cytogenetic...

  8. A survey of natural terrestrial and airborne radionuclides in moss samples from the peninsular Thailand.

    Science.gov (United States)

    Wattanavatee, Komrit; Krmar, Miodrag; Bhongsuwan, Tripob

    2017-10-01

    The aim of this study was to determine the activity concentrations of natural terrestrial radionuclides ( 238 U, 226 Ra, 232 Th and 40 K) and airborne radionuclides ( 210 Pb, 210 Pb ex and 7 Be) in natural terrestrial mosses. The collected moss samples (46) representing 17 species were collected from 17 sampling localities in the National Parks and Wildlife Sanctuaries of Thailand, situated in the mountainous areas between the northern and the southern ends of peninsular Thailand (∼7-12 °N, 99-102 °E). Activity concentrations of radionuclides in the samples were measured using a low background gamma spectrometer. The results revealed non-uniform spatial distributions of all the radionuclides in the study area. Principal component analysis and cluster analysis revealed two distinct origins for the studied radionuclides, and furthermore, the Pearson correlations were strong within 226 Ra, 232 Th, 238 U and 40 K as well as within 210 Pb and 210 Pb ex , but there was no significant correlation between these two groups. Also 7 Be was uncorrelated to the others, as expected due to different origins of the airborne and terrestrial radionuclides. The radionuclide activities of moss samples varied by moss species, topography, geology, and meteorology of each sampling area. The observed abnormally high concentrations of some radionuclides probably indicate that the concentrations of airborne and terrestrial radionuclides in moss samples were directly related to local geological features of the sampling site, or that high levels of 7 Be were most probably linked with topography and regional NE monsoonal winds from mainland China. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Comparative study of Uranium estimation in drinking water samples of seismically active regions of NW-Himalayas, Himachal Pradesh and SW-Punjab, India using Laser Fluorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Bajwa, B.; Arora, V.; Saini, K. [Guru Nanak Dev University, Amritsar (India)

    2014-07-01

    The Laser Fluorimetry Technique has been used for the microanalysis of uranium content in drinking water samples collected from different sources like the hand pumps and natural springs of seismically active regions of Chamba and Dharamshala, Himachal Pradesh, NW-Himalayas and Bathinda and Mansa districts of SW-Punjab, state, India. The purpose of this study was to investigate the uranium concentration levels of ground water being used for drinking purposes and to determine its health effects, if any, to the local population of these regions. In the present study 47 samples of drinking water collected from different villages of the seismic active belt of Chamba and Dharamshala region of Himachal Pradesh, India have been analyzed for chemical and radiological toxicity. Uranium concentration in drinking water sample of study region ranged between 2.7 μgL{sup -1} - 53.9 μgL{sup -1} with an average value of 20.1 μgL{sup -1}. In SW-Punjab, Uranium concentration in 76 drinking water samples has been found to vary between 0.13 μgL{sup -1} and 676 μgL{sup -1} with an average of 90.2 μgL{sup -1}. Data analysis reveals that, 19% samples of NW-Himalayas water have uranium concentration higher than recommended limit of 30 μgL{sup -1} (WHO, 2011) while none of the samples exceeds the threshold of 60 μgL{sup -1} recommended by AERB, DAE, India, 2004. On the other hand, 64% water samples of SW-Punjab have uranium concentration higher than recommended limit of 30 μgL{sup -1} (WHO, 2011) while 39% water samples exceeds the threshold of 60 μgL{sup -1} recommended by AERB, DAE, India, 2004. Document available in abstract form only. (authors)

  10. Analysis of intraosseous samples in endotoxemic shock--an experimental study in the anaesthetised pig.

    Science.gov (United States)

    Strandberg, G; Larsson, A; Lipcsey, M; Berglund, L; Eriksson, M

    2014-03-01

    Intraosseous (IO) access is used in emergency situations to allow rapid initiation of treatment. IO access is also sometimes used for blood sampling, although data on accuracy of such sampling in critical illness are limited. There is also a potential risk that bone marrow fragments in IO samples may damage laboratory equipment. It is ethically questionable to perform a simultaneous comparison between IO and arterial/venous sampling in critically ill humans. We have, thus, studied the analytical performance of IO sampling in a porcine septic shock model using a cartridge-based analyser. Eight pigs with endotoxin-induced septic shock were sampled hourly for 6 h, and analysed for blood gases, acid base status, haemoglobin, glucose and lactate using point of care instruments. Samples were taken from three IO cannulae (tibia bilaterally, one with infusion, and humerus), one arterial and one venous. An interaction test was used to assess changes in agreement between methods over time. Bland–Altman plots were constructed to study bias between methods. There were, to a varying extent, differences between IO and arterial/venous levels for all studied variables, but agreement did not change significantly during the experiment. A general finding was a large dispersion of differences between methods. IO sample values should be treated with caution in this setting but may add useful information to the clinical picture. The tibia or humerus may be used for sampling. IO infusion decreases agreement, thus sampling during infusion should be avoided.

  11. Sequence tagging reveals unexpected modifications in toxicoproteomics

    Science.gov (United States)

    Dasari, Surendra; Chambers, Matthew C.; Codreanu, Simona G.; Liebler, Daniel C.; Collins, Ben C.; Pennington, Stephen R.; Gallagher, William M.; Tabb, David L.

    2010-01-01

    Toxicoproteomic samples are rich in posttranslational modifications (PTMs) of proteins. Identifying these modifications via standard database searching can incur significant performance penalties. Here we describe the latest developments in TagRecon, an algorithm that leverages inferred sequence tags to identify modified peptides in toxicoproteomic data sets. TagRecon identifies known modifications more effectively than the MyriMatch database search engine. TagRecon outperformed state of the art software in recognizing unanticipated modifications from LTQ, Orbitrap, and QTOF data sets. We developed user-friendly software for detecting persistent mass shifts from samples. We follow a three-step strategy for detecting unanticipated PTMs in samples. First, we identify the proteins present in the sample with a standard database search. Next, identified proteins are interrogated for unexpected PTMs with a sequence tag-based search. Finally, additional evidence is gathered for the detected mass shifts with a refinement search. Application of this technology on toxicoproteomic data sets revealed unintended cross-reactions between proteins and sample processing reagents. Twenty five proteins in rat liver showed signs of oxidative stress when exposed to potentially toxic drugs. These results demonstrate the value of mining toxicoproteomic data sets for modifications. PMID:21214251

  12. Definitions of love in a sample of British women: an empirical study using Q methodology.

    Science.gov (United States)

    Watts, Simon; Stenner, Paul

    2014-09-01

    Social psychological research has increasingly acknowledged that any pretensions to a singular theory of love should be replaced with a concern about its affirmation and what people actually say and do in love's name. Lee's (1977) love styles research and Sternberg's (1995) theory of love as a story are prime examples. Despite traditional definitions of love in western cultures being dominated by feminine images and tales of gender difference, however, the personal definitions and experiences of women have received comparatively little empirical attention, particularly in recent years and despite some well-documented changes in their cultural circumstances. This study remedies that situation through presentation of a Q methodological study in which a convenience sample of 59 British women were asked to Q sort 54 single-word descriptors of love to define love as they had experienced it. Factor analysis of the resulting Q sorts revealed six distinct definitions of love, interpreted as 'attraction, passion & romance', 'unconditional love', 'sex & fun', 'friendship & spirituality', 'a permanent commitment', and 'separate people, separate lives'. The six definitions are then discussed in terms of their allegiance to traditionally feminine and/or masculine values and as a means of highlighting the changing face of Britain's relational culture. © 2013 The British Psychological Society.

  13. [Study of spatial stratified sampling strategy of Oncomelania hupensis snail survey based on plant abundance].

    Science.gov (United States)

    Xun-Ping, W; An, Z

    2017-07-27

    Objective To optimize and simplify the survey method of Oncomelania hupensis snails in marshland endemic regions of schistosomiasis, so as to improve the precision, efficiency and economy of the snail survey. Methods A snail sampling strategy (Spatial Sampling Scenario of Oncomelania based on Plant Abundance, SOPA) which took the plant abundance as auxiliary variable was explored and an experimental study in a 50 m×50 m plot in a marshland in the Poyang Lake region was performed. Firstly, the push broom surveyed data was stratified into 5 layers by the plant abundance data; then, the required numbers of optimal sampling points of each layer through Hammond McCullagh equation were calculated; thirdly, every sample point in the line with the Multiple Directional Interpolation (MDI) placement scheme was pinpointed; and finally, the comparison study among the outcomes of the spatial random sampling strategy, the traditional systematic sampling method, the spatial stratified sampling method, Sandwich spatial sampling and inference and SOPA was performed. Results The method (SOPA) proposed in this study had the minimal absolute error of 0.213 8; and the traditional systematic sampling method had the largest estimate, and the absolute error was 0.924 4. Conclusion The snail sampling strategy (SOPA) proposed in this study obtains the higher estimation accuracy than the other four methods.

  14. Structure defects in malachite revealed by positron annihilation

    International Nuclear Information System (INIS)

    Geffroy, B.; Diallo, I.; Paulin, R.

    1984-01-01

    Positron lifetime is measured between 77 and 400 K in two malachite samples with different mineralogical structures. The complex spectrum found in zoned malachite reveals a microporosity which remains stable in this range of temperature. Besides, above 200 K, equilibrium defects appear. Their formation energy is estimated to be Esub(f) = 0.27 +- 0.02 eV [fr

  15. Structure defects in malachite revealed by positron annihilation

    Energy Technology Data Exchange (ETDEWEB)

    Geffroy, B; Diallo, I; Paulin, R [Institut National des Sciences et Techniques Nucleaires, CEN/Saclay, 91 - Gif-sur-Yvette (France)

    1984-01-01

    Positron lifetime is measured between 77 and 400 K in two malachite samples with different mineralogical structures. The complex spectrum found in zoned malachite reveals a microporosity which remains stable in this range of temperature. Besides, above 200 K, equilibrium defects appear. Their formation energy is estimated to be Esub(f) = 0.27 +- 0.02 eV.

  16. Study on graphite samples for nuclear usage

    International Nuclear Information System (INIS)

    Suarez, J.C.M.; Silva Roseira, M. da

    1994-01-01

    Available as short communication only. The graphite, due to its properties (mechanical strength, thermal conductivity, high-temperature stability, machinability etc.) have many industrial applications, and consequently, an important strategic value. In the nuclear area, it has been used as moderator and reflector of neutrons in the fission process of uranium. The graphite can be produced from many types of carbonaceous materials by a variety of process dominated by the manufactures. This is the reason why there are in the world market a lot of graphite types with different physical and mechanical properties. The present investigation studies some physical characteristics of the graphite samples destined to use in a nuclear reactor. (author). 8 refs, 1 fig, 1 tab

  17. Systematic sampling with errors in sample locations

    DEFF Research Database (Denmark)

    Ziegel, Johanna; Baddeley, Adrian; Dorph-Petersen, Karl-Anton

    2010-01-01

    analysis using point process methods. We then analyze three different models for the error process, calculate exact expressions for the variances, and derive asymptotic variances. Errors in the placement of sample points can lead to substantial inflation of the variance, dampening of zitterbewegung......Systematic sampling of points in continuous space is widely used in microscopy and spatial surveys. Classical theory provides asymptotic expressions for the variance of estimators based on systematic sampling as the grid spacing decreases. However, the classical theory assumes that the sample grid...... is exactly periodic; real physical sampling procedures may introduce errors in the placement of the sample points. This paper studies the effect of errors in sample positioning on the variance of estimators in the case of one-dimensional systematic sampling. First we sketch a general approach to variance...

  18. Abortion experiences among Zanzibari women: a chain-referral sampling study

    OpenAIRE

    Norris, Alison; Harrington, Bryna J.; Grossman, Daniel; Hemed, Maryam; Hindin, Michelle J.

    2016-01-01

    Background In Zanzibar, a semi-autonomous region of Tanzania, induced abortion is illegal but common, and fewer than 12?% of married reproductive-aged women use modern contraception. As part of a multi-method study about contraception and consequences of unwanted pregnancies, the objective of this study was to understand the experiences of Zanzibari women who terminated pregnancies. Methods The cross-sectional study was set in Zanzibar, Tanzania. Participants were a community-based sample of ...

  19. An efficient method for sampling the essential subspace of proteins

    NARCIS (Netherlands)

    Amadei, A; Linssen, A.B M; de Groot, B.L.; van Aalten, D.M.F.; Berendsen, H.J.C.

    A method is presented for a more efficient sampling of the configurational space of proteins as compared to conventional sampling techniques such as molecular dynamics. The method is based on the large conformational changes in proteins revealed by the ''essential dynamics'' analysis. A form of

  20. The one-sample PARAFAC approach reveals molecular size distributions of fluorescent components in dissolved organic matter

    DEFF Research Database (Denmark)

    Wünsch, Urban; Murphy, Kathleen R.; Stedmon, Colin

    2017-01-01

    Molecular size plays an important role in dissolved organic matter (DOM) biogeochemistry, but its relationship with the fluorescent fraction of DOM (FDOM) remains poorly resolved. Here high-performance size exclusion chromatography (HPSEC) was coupled to fluorescence emission-excitation (EEM...... but not their spectral properties. Thus, in contrast to absorption measurements, bulk fluorescence is unlikely to reliably indicate the average molecular size of DOM. The one-sample approach enables robust and independent cross-site comparisons without large-scale sampling efforts and introduces new analytical...... opportunities for elucidating the origins and biogeochemical properties of FDOM...

  1. Merging metagenomics and geochemistry reveals environmental controls on biological diversity and evolution.

    Science.gov (United States)

    Alsop, Eric B; Boyd, Eric S; Raymond, Jason

    2014-05-28

    The metabolic strategies employed by microbes inhabiting natural systems are, in large part, dictated by the physical and geochemical properties of the environment. This study sheds light onto the complex relationship between biology and environmental geochemistry using forty-three metagenomes collected from geochemically diverse and globally distributed natural systems. It is widely hypothesized that many uncommonly measured geochemical parameters affect community dynamics and this study leverages the development and application of multidimensional biogeochemical metrics to study correlations between geochemistry and microbial ecology. Analysis techniques such as a Markov cluster-based measure of the evolutionary distance between whole communities and a principal component analysis (PCA) of the geochemical gradients between environments allows for the determination of correlations between microbial community dynamics and environmental geochemistry and provides insight into which geochemical parameters most strongly influence microbial biodiversity. By progressively building from samples taken along well defined geochemical gradients to samples widely dispersed in geochemical space this study reveals strong links between the extent of taxonomic and functional diversification of resident communities and environmental geochemistry and reveals temperature and pH as the primary factors that have shaped the evolution of these communities. Moreover, the inclusion of extensive geochemical data into analyses reveals new links between geochemical parameters (e.g. oxygen and trace element availability) and the distribution and taxonomic diversification of communities at the functional level. Further, an overall geochemical gradient (from multivariate analyses) between natural systems provides one of the most complete predictions of microbial taxonomic and functional composition. Clustering based on the frequency in which orthologous proteins occur among metagenomes

  2. What about N? A methodological study of sample-size reporting in focus group studies.

    Science.gov (United States)

    Carlsen, Benedicte; Glenton, Claire

    2011-03-11

    Focus group studies are increasingly published in health related journals, but we know little about how researchers use this method, particularly how they determine the number of focus groups to conduct. The methodological literature commonly advises researchers to follow principles of data saturation, although practical advise on how to do this is lacking. Our objectives were firstly, to describe the current status of sample size in focus group studies reported in health journals. Secondly, to assess whether and how researchers explain the number of focus groups they carry out. We searched PubMed for studies that had used focus groups and that had been published in open access journals during 2008, and extracted data on the number of focus groups and on any explanation authors gave for this number. We also did a qualitative assessment of the papers with regard to how number of groups was explained and discussed. We identified 220 papers published in 117 journals. In these papers insufficient reporting of sample sizes was common. The number of focus groups conducted varied greatly (mean 8.4, median 5, range 1 to 96). Thirty seven (17%) studies attempted to explain the number of groups. Six studies referred to rules of thumb in the literature, three stated that they were unable to organize more groups for practical reasons, while 28 studies stated that they had reached a point of saturation. Among those stating that they had reached a point of saturation, several appeared not to have followed principles from grounded theory where data collection and analysis is an iterative process until saturation is reached. Studies with high numbers of focus groups did not offer explanations for number of groups. Too much data as a study weakness was not an issue discussed in any of the reviewed papers. Based on these findings we suggest that journals adopt more stringent requirements for focus group method reporting. The often poor and inconsistent reporting seen in these

  3. What about N? A methodological study of sample-size reporting in focus group studies

    Directory of Open Access Journals (Sweden)

    Glenton Claire

    2011-03-01

    Full Text Available Abstract Background Focus group studies are increasingly published in health related journals, but we know little about how researchers use this method, particularly how they determine the number of focus groups to conduct. The methodological literature commonly advises researchers to follow principles of data saturation, although practical advise on how to do this is lacking. Our objectives were firstly, to describe the current status of sample size in focus group studies reported in health journals. Secondly, to assess whether and how researchers explain the number of focus groups they carry out. Methods We searched PubMed for studies that had used focus groups and that had been published in open access journals during 2008, and extracted data on the number of focus groups and on any explanation authors gave for this number. We also did a qualitative assessment of the papers with regard to how number of groups was explained and discussed. Results We identified 220 papers published in 117 journals. In these papers insufficient reporting of sample sizes was common. The number of focus groups conducted varied greatly (mean 8.4, median 5, range 1 to 96. Thirty seven (17% studies attempted to explain the number of groups. Six studies referred to rules of thumb in the literature, three stated that they were unable to organize more groups for practical reasons, while 28 studies stated that they had reached a point of saturation. Among those stating that they had reached a point of saturation, several appeared not to have followed principles from grounded theory where data collection and analysis is an iterative process until saturation is reached. Studies with high numbers of focus groups did not offer explanations for number of groups. Too much data as a study weakness was not an issue discussed in any of the reviewed papers. Conclusions Based on these findings we suggest that journals adopt more stringent requirements for focus group method

  4. A Shandon PapSpin liquid-based gynecological test: A split-sample and direct-to-vial test with histology follow-up study

    Directory of Open Access Journals (Sweden)

    Rimiene J

    2010-01-01

    Full Text Available Background: Studies for liquid-based Papanicolaou (Pap tests reveal that liquid-based cytology (LBC is a safe and effective alternative to the conventional Pap smear. Although there is research on ThinPrep and SurePath systems, information is lacking to evaluate the efficiency and effectiveness of systems based on cytocentrifugation. This study is designed to determine the sensitivity and specificity of the Shandon PapSpin (ThermoShandon, Pittsburgh, Pennsylvania, USA liquid-based gynecological system. We used split-sample and direct-to-vial study design. Materials and Methods: 2,945 women referred to prophylactic check-up were enrolled in this study. Split sample design was used in 1,500 women and residual cervical cytology specimen from all these cases was placed in fluid for PapSpin preparation after performing conventional smear. The direct-to-vial study was carried out in another cohort of 1,445 women in whom the entire cervical material was investigated using only the PapSpin technique. Follow up histological diagnoses for 141 women were obtained from both study arms following 189 abnormal cytology cases. 80 LBC cases from the split sample group and 61 LBC cases in the direct-to-vial group were correlated with the histology results. The sensitivity and secificity of the conventional smear and PapSpin tests in both study arms were compared. Results: In the split sample group, conventional smears showed a higher proportion of ASC-US (atypical cells undetermined significance: 31 (2.1% vs 10 (0.7% in PapSpin (P = 0.001. A higher proportion of unsatisfactory samples was found in the conventional smear group: 25 (1.7% vs 6 (0.4% cases (P = 0.001. In the split sample group, the sensitivity of the conventional and PapSpin tests was 68.7% vs 78.1%, and the specificity 93.8% vs 91.8%, respectively. In the direct to vial group PapSpin sensitivity was 75.9% and specificity 96.5%. The differences in sensitivity and specificity were not significant. The

  5. Investigating causal associations between use of nicotine, alcohol, caffeine and cannabis: a two-sample bidirectional Mendelian randomization study.

    Science.gov (United States)

    Verweij, Karin J H; Treur, Jorien L; Vink, Jacqueline M

    2018-07-01

    Epidemiological studies consistently show co-occurrence of use of different addictive substances. Whether these associations are causal or due to overlapping underlying influences remains an important question in addiction research. Methodological advances have made it possible to use published genetic associations to infer causal relationships between phenotypes. In this exploratory study, we used Mendelian randomization (MR) to examine the causality of well-established associations between nicotine, alcohol, caffeine and cannabis use. Two-sample MR was employed to estimate bidirectional causal effects between four addictive substances: nicotine (smoking initiation and cigarettes smoked per day), caffeine (cups of coffee per day), alcohol (units per week) and cannabis (initiation). Based on existing genome-wide association results we selected genetic variants associated with the exposure measure as an instrument to estimate causal effects. Where possible we applied sensitivity analyses (MR-Egger and weighted median) more robust to horizontal pleiotropy. Most MR tests did not reveal causal associations. There was some weak evidence for a causal positive effect of genetically instrumented alcohol use on smoking initiation and of cigarettes per day on caffeine use, but these were not supported by the sensitivity analyses. There was also some suggestive evidence for a positive effect of alcohol use on caffeine use (only with MR-Egger) and smoking initiation on cannabis initiation (only with weighted median). None of the suggestive causal associations survived corrections for multiple testing. Two-sample Mendelian randomization analyses found little evidence for causal relationships between nicotine, alcohol, caffeine and cannabis use. © 2018 Society for the Study of Addiction.

  6. Thermoluminescence and X-ray diffraction studies on sliced ancient porcelain samples

    International Nuclear Information System (INIS)

    Leung, P.L.; Yang, B.

    1999-01-01

    The thermal activation characteristics (TACs) of the sensitivity of the '110 deg. C' peak in 14 sliced ancient Chinese porcelain samples are studied. Comparing with the TACs of natural quartz and synthetic mullite, the relation between the TACs and the composition of the sample is discussed with reference to the X-ray diffraction (XRD) spectra. It is suggested that in some cases, contribution of the porcelain components other than quartz to the TACs is not negligible

  7. Thermoluminescence and X-ray diffraction studies on sliced ancient porcelain samples

    Energy Technology Data Exchange (ETDEWEB)

    Leung, P.L.; Yang, B. E-mail: yangbr@bnu.edu.cn

    1999-09-01

    The thermal activation characteristics (TACs) of the sensitivity of the '110 deg. C' peak in 14 sliced ancient Chinese porcelain samples are studied. Comparing with the TACs of natural quartz and synthetic mullite, the relation between the TACs and the composition of the sample is discussed with reference to the X-ray diffraction (XRD) spectra. It is suggested that in some cases, contribution of the porcelain components other than quartz to the TACs is not negligible.

  8. Thermoluminescence and X-ray diffraction studies on sliced ancient porcelain samples

    Science.gov (United States)

    Leung, P. L.; Yang, B.

    1999-09-01

    The thermal activation characteristics (TACs) of the sensitivity of the '110°C' peak in 14 sliced ancient Chinese porcelain samples are studied. Comparing with the TACs of natural quartz and synthetic mullite, the relation between the TACs and the composition of the sample is discussed with reference to the X-ray diffraction (XRD) spectra. It is suggested that in some cases, contribution of the porcelain components other than quartz to the TACs is not negligible.

  9. Sample preparation for large-scale bioanalytical studies based on liquid chromatographic techniques.

    Science.gov (United States)

    Medvedovici, Andrei; Bacalum, Elena; David, Victor

    2018-01-01

    Quality of the analytical data obtained for large-scale and long term bioanalytical studies based on liquid chromatography depends on a number of experimental factors including the choice of sample preparation method. This review discusses this tedious part of bioanalytical studies, applied to large-scale samples and using liquid chromatography coupled with different detector types as core analytical technique. The main sample preparation methods included in this paper are protein precipitation, liquid-liquid extraction, solid-phase extraction, derivatization and their versions. They are discussed by analytical performances, fields of applications, advantages and disadvantages. The cited literature covers mainly the analytical achievements during the last decade, although several previous papers became more valuable in time and they are included in this review. Copyright © 2017 John Wiley & Sons, Ltd.

  10. Enhancing sample preparation capabilities for accelerator mass spectrometry radiocarbon and radiocalcium studies

    International Nuclear Information System (INIS)

    Taylor, R.E.

    1991-01-01

    With support provided by the LLNL Accelerator Mass Spectrometry Laboratory, the UCR Radiocarbon Laboratory continued its studies involving sample pretreatment and target preparation for both AMS radiocarbon ( 14 C) and radiocalcium ( 41 Ca) involving applications to archaeologically -- and paleoanthropologically- related samples. With regard to AMS 14 C-related studies, we have extended the development of a series of procedures which have, as their initial goal, the capability to combust several hundred microgram amounts of a chemically-pretreated organic sample and convert the resultant CO 2 to graphitic carbon which will consistently yield relatively high 13 C - ion currents and blanks which will yield, on a consistent basis, 14 C count rates at or below 0.20% modern, giving an 2 sigma age limit of >50,000 yr BP

  11. Astronauts Armstrong and Aldrin study rock samples during field trip

    Science.gov (United States)

    1969-01-01

    Astronaut Neil Armstrong, commander of the Apollo 11 lunar landing mission, and Astronaut Edwin Aldrin, Lunar module pilot for Apollo 11, study rock samples during a geological field trip to the Quitman Mountains area near the Fort Quitman ruins in far west Texas.

  12. Extensive monitoring through multiple blood samples in professional soccer players

    DEFF Research Database (Denmark)

    Heisterberg, Mette F; Fahrenkrug, Jan; Krustrup, Peter

    2013-01-01

    of the season. Leucocytes decreased with increased physical training. Lymphocytes decreased at the end of the season. VO2max decreased towards the end of the season whereas no significant changes were observed in the IE2 test.The regular blood samples from elite soccer players reveal significant changes......ABSTRACT: The aim of this study was to make a comprehensive gathering of consecutive detailed blood samples from professional soccer players, and to analyze different blood parameters in relation to seasonal changes in training and match exposure.Blood samples were collected five times during a six...... months period and analyzed for 37 variables in 27 professional soccer players from the best Danish league. Additionally, players were tested for body composition, VO2max and physical performance by the Yo-Yo intermittent endurance sub-max test (IE2).Multiple variations in blood parameters occurred during...

  13. A study on the weather sampling method for probabilistic consequence analysis

    International Nuclear Information System (INIS)

    Oh, Hae Cheol

    1996-02-01

    The main task of probabilistic accident consequence analysis model is to predict the radiological situation and to provide a reliable quantitative data base for making decisions on countermeasures. The magnitude of accident consequence is depended on the characteristic of the accident and the weather coincident. In probabilistic accident consequence analysis, it is necessary to repeat the atmospheric dispersion calculation with several hundreds of weather sequences to predict the full distribution of consequences which may occur following a postulated accident release. It is desirable to select a representative sample of weather sequences from a meteorological record which is typical of the area over which the released radionuclides will disperse and which spans a sufficiently long period. The selection process is done by means of sampling techniques from a full year of hourly weather data characteristic of the plant site. In this study, the proposed Weighted importance sampling method selects proportional to the each bin size to closely approximate the true frequency distribution of weather condition at the site. The Weighted importance sampling method results in substantially less sampling uncertainty than the previous technique. The proposed technique can result in improve confidence in risk estimates

  14. Rapid Detection of Salmonella in Food and Beverage Samples by Polymerase Chain Reaction

    Directory of Open Access Journals (Sweden)

    Radji, M.

    2010-01-01

    Full Text Available Polymerase chain reaction (PCR assay had been used to detect Salmonella in food and beverage samples using suitable primers which are based on specific invA gene of Salmonella. Twenty nine samples were collected from street food counters and some canteens in Margonda Street, Depok, West Java, Indonesia. It was found that five of twenty nine samples were detected to contain Salmonella and showed the presence of the amplified product of the size 244 bp. The method of PCR demonstrated the specificity of invA primers for detection of Salmonella as confirmed by biochemical and serological assay. The results of this study revealed that PCR was a rapid and useful tool for detection of Salmonella in food and beverage samples.

  15. Study of the Prevalence of Causative Bacterial&Protozoal Agents of in Stool Samples of 470 Gastroenteritis Patients Referring to the Nikoopour Clinic in Yazd,Iran

    Directory of Open Access Journals (Sweden)

    MR Sharifi

    2004-04-01

    Full Text Available Interoduction: Gasteroenteritis is one of the problems worth consideration all over the world. It is one of the important causes of mortality, especially in children < 5 years of age, in developing countries including Iran. The aim of this descriptive study was to determine the demographic conditions influencing the presence of causative bacteria and protozoa, followed by antibiograms of isolated bacteria from stool samples of patients with gasteroenteritis referring to Nikoopour Clinic in the city of Yazd, Iran from 1998 – 2001. Materials and method: A total of 470 samples were microbiologically examined by direct method, culture and then antibiogramed. In order to isolate the possible bacteria, differential and selected media were used. Also, wet – mount technique was applied for detection of protozoa. Results: Results revealed that 272 samples (57.9% were infected by pathogenic bacteria or protozoa. 138 (50.8% pathogenic specimens were from male patients and the remaining 134(49.3% were from female patients. Isolated species were: Enteropathogenic E.coli 117(43%, Shigella 51(18.8%, Salmonella.interetidis 25(9.2%, C.jejuni 16(5.9%, Giardia lambdia 51(18.8% and Amoebae spp 12(4.4%. The most commonly detected shigella species was dysenteriae, (74.5% while boydii with 2% was the least common type observed in the specimens. Except shigella, all the other bacteria were more common in males than female, but insignificant statistically. In order to determine the sensitivity and/or resistance of pathogenic bacteria, antibiogram test was performed using selected antibiotic disks such as Ampicillin, Nalidixic Acid, Ciprofloxacin, Gentamycin and Sulfamethaxazole. Conclusion: Results revealed that some patients were probably infected by pathogenic factors other than bacteria or protozoa. Since all viruses and parasites are almost resistant to antibiotics and on the other hand, administration of antibiotics may lead to resistance of bacterial agents

  16. Serial Sampling of Serum Protein Biomarkers for Monitoring Human Traumatic Brain Injury Dynamics: A Systematic Review.

    Science.gov (United States)

    Thelin, Eric Peter; Zeiler, Frederick Adam; Ercole, Ari; Mondello, Stefania; Büki, András; Bellander, Bo-Michael; Helmy, Adel; Menon, David K; Nelson, David W

    2017-01-01

    The proteins S100B, neuron-specific enolase (NSE), glial fibrillary acidic protein (GFAP), ubiquitin carboxy-terminal hydrolase L1 (UCH-L1), and neurofilament light (NF-L) have been serially sampled in serum of patients suffering from traumatic brain injury (TBI) in order to assess injury severity and tissue fate. We review the current literature of serum level dynamics of these proteins following TBI and used the term "effective half-life" ( t 1/2 ) in order to describe the "fall" rate in serum. Through searches on EMBASE, Medline, and Scopus, we looked for articles where these proteins had been serially sampled in serum in human TBI. We excluded animal studies, studies with only one presented sample and studies without neuroradiological examinations. Following screening (10,389 papers), n  = 122 papers were included. The proteins S100B ( n  = 66) and NSE ( n  = 27) were the two most frequent biomarkers that were serially sampled. For S100B in severe TBI, a majority of studies indicate a t 1/2 of about 24 h, even if very early sampling in these patients reveals rapid decreases (1-2 h) though possibly of non-cerebral origin. In contrast, the t 1/2 for NSE is comparably longer, ranging from 48 to 72 h in severe TBI cases. The protein GFAP ( n  = 18) appears to have t 1/2 of about 24-48 h in severe TBI. The protein UCH-L1 ( n  = 9) presents a t 1/2 around 7 h in mild TBI and about 10 h in severe. Frequent sampling of these proteins revealed different trajectories with persisting high serum levels, or secondary peaks, in patients with unfavorable outcome or in patients developing secondary detrimental events. Finally, NF-L ( n  = 2) only increased in the few studies available, suggesting a serum availability of >10 days. To date, automated assays are available for S100B and NSE making them faster and more practical to use. Serial sampling of brain-specific proteins in serum reveals different temporal trajectories that should be

  17. Serial Sampling of Serum Protein Biomarkers for Monitoring Human Traumatic Brain Injury Dynamics: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Eric Peter Thelin

    2017-07-01

    Full Text Available BackgroundThe proteins S100B, neuron-specific enolase (NSE, glial fibrillary acidic protein (GFAP, ubiquitin carboxy-terminal hydrolase L1 (UCH-L1, and neurofilament light (NF-L have been serially sampled in serum of patients suffering from traumatic brain injury (TBI in order to assess injury severity and tissue fate. We review the current literature of serum level dynamics of these proteins following TBI and used the term “effective half-life” (t1/2 in order to describe the “fall” rate in serum.Materials and methodsThrough searches on EMBASE, Medline, and Scopus, we looked for articles where these proteins had been serially sampled in serum in human TBI. We excluded animal studies, studies with only one presented sample and studies without neuroradiological examinations.ResultsFollowing screening (10,389 papers, n = 122 papers were included. The proteins S100B (n = 66 and NSE (n = 27 were the two most frequent biomarkers that were serially sampled. For S100B in severe TBI, a majority of studies indicate a t1/2 of about 24 h, even if very early sampling in these patients reveals rapid decreases (1–2 h though possibly of non-cerebral origin. In contrast, the t1/2 for NSE is comparably longer, ranging from 48 to 72 h in severe TBI cases. The protein GFAP (n = 18 appears to have t1/2 of about 24–48 h in severe TBI. The protein UCH-L1 (n = 9 presents a t1/2 around 7 h in mild TBI and about 10 h in severe. Frequent sampling of these proteins revealed different trajectories with persisting high serum levels, or secondary peaks, in patients with unfavorable outcome or in patients developing secondary detrimental events. Finally, NF-L (n = 2 only increased in the few studies available, suggesting a serum availability of >10 days. To date, automated assays are available for S100B and NSE making them faster and more practical to use.ConclusionSerial sampling of brain-specific proteins in serum reveals

  18. A recommended procedure for establishing the source level relationships between heroin case samples of unknown origins

    Directory of Open Access Journals (Sweden)

    Kar-Weng Chan

    2014-06-01

    Full Text Available A recent concern of how to reliably establish the source level relationships of heroin case samples is addressed in this paper. Twenty-two trafficking heroin case samples of unknown origins seized from two major regions (Kuala Lumpur and Penang in Malaysia were studied. A procedure containing six major steps was followed to analyze and classify these samples. Subsequently, with the aid of statistical control samples, reliability of the clustering result was assessed. The final outcome reveals that the samples seized from the two regions in 2013 had highly likely originated from two different sources. Hence, the six-step procedure is sufficient for any chemist who attempts to assess the relative source level relationships of heroin samples.

  19. Integrity of the Human Faecal Microbiota following Long-Term Sample Storage.

    Directory of Open Access Journals (Sweden)

    Elahe Kia

    Full Text Available In studies of the human microbiome, faecal samples are frequently used as a non-invasive proxy for the study of the intestinal microbiota. To obtain reliable insights, the need for bacterial DNA of high quality and integrity following appropriate faecal sample collection and preservation steps is paramount. In a study of dietary mineral balance in the context of type 2 diabetes (T2D, faecal samples were collected from healthy and T2D individuals throughout a 13-day residential trial. These samples were freeze-dried, then stored mostly at -20°C from the trial date in 2000/2001 until the current research in 2014. Given the relative antiquity of these samples (~14 years, we sought to evaluate DNA quality and comparability to freshly collected human faecal samples. Following the extraction of bacterial DNA, gel electrophoresis indicated that our DNA extracts were more sheared than extracts made from freshly collected faecal samples, but still of sufficiently high molecular weight to support amplicon-based studies. Likewise, spectrophotometric assessment of extracts revealed that they were of high quality and quantity. A subset of bacterial 16S rRNA gene amplicons were sequenced using Illumina MiSeq and compared against publicly available sequence data representing a similar cohort analysed by the American Gut Project (AGP. Notably, our bacterial community profiles were highly consistent with those from the AGP data. Our results suggest that when faecal specimens are stored appropriately, the microbial profiles are preserved and robust to extended storage periods.

  20. Study of polyconsumption in a 2005 Bogota driver's sample

    Directory of Open Access Journals (Sweden)

    Óscar Armando Sánchez Cardozo

    2007-01-01

    Full Text Available Background. We do not know of studies in our city that indicate the degree of poly illicit drugs consumption in motor vehicles drivers. Use of illicit drugs can explain in some cases the lack of agreement among measurement of breath alcohol test, blood alcohol concentration, and clinical examination in motor vehicles drivers when they are suspects of alcoholic intoxication. In this report we want to center on showing the use of illicit drugs and their clinical manifestations in a sample of motor vehicles drivers. Objective. To determine the consumption of illicit drugs in a sample of motor vehicle drivers, when they are suspects of alcoholic intoxication. Materials and methods. We took a representative sample within 68 motor vehicle drivers. We performed on all of them clinical examination, measurement of breath alcohol tests and blood alcohol concentration. Also we collected urine samples. Five (5 substances were investigated according to their high prevalence in our population: opiate, marijuana, cocaine, amphetamines and benzodiazepines. Results.There were seven cases of illicit drug consumption: the most frequent combination found was (5-7 cases alcohol plus marijuana. In three cases we found consumption of three illicit drugs: 2 cases have alcohol, marijuana and cocaine. Only one case of alcohol, benzodiazepine and cocaine. Conclusions. In the sample analyzed the use of illicit drugs was 10.14 %. The most common form of use is a depressor with a stimulant. If it is recent, it diminishes the neurological manifestations, but it does not affect the presentation nor the severity of the rotacional nystagmus. The alterations of the superior mental functions were seen to be associated with alcohol consumption plus benzodiazepines. Combination of two depressors increases the motor alterations and seems that it alters the superior mental functions. In the negative clinical examinations it was concluded that there was no alcohol intoxication and no

  1. Eating Disorders Among a Community-based Sample of Chilean Female Adolescents

    Science.gov (United States)

    Granillo, M. Teresa; Grogan-Kaylor, Andrew; Delva, Jorge; Castillo, Marcela

    2010-01-01

    The purpose of this study was to explore the prevalence and correlates of eating disorders among a community-based sample of female Chilean adolescents. Data were collected through structured interviews with 420 female adolescents residing in Santiago, Chile. Approximately 4% of the sample reported ever being diagnosed with an eating disorder. Multivariate logistic regression analyses revealed that those with higher symptoms of anxiety and who had tried cigarettes were significantly more likely to have been diagnosed with an eating disorder. Findings indicate that Chilean female adolescents are at risk of eating disorders and that eating disorders, albeit maladaptive, may be a means to cope with negative affect, specifically anxiety. PMID:22121329

  2. Effects of sample size on the second magnetization peak in ...

    Indian Academy of Sciences (India)

    the sample size decreases – a result that could be interpreted as a size effect in the order– disorder vortex matter phase transition. However, local magnetic measurements trace this effect to metastable disordered vortex states, revealing the same order–disorder transition induction in samples of different size. Keywords.

  3. The impact of sample size and marker selection on the study of haplotype structures

    Directory of Open Access Journals (Sweden)

    Sun Xiao

    2004-03-01

    Full Text Available Abstract Several studies of haplotype structures in the human genome in various populations have found that the human chromosomes are structured such that each chromosome can be divided into many blocks, within which there is limited haplotype diversity. In addition, only a few genetic markers in a putative block are needed to capture most of the diversity within a block. There has been no systematic empirical study of the effects of sample size and marker set on the identified block structures and representative marker sets, however. The purpose of this study was to conduct a detailed empirical study to examine such impacts. Towards this goal, we have analysed three representative autosomal regions from a large genome-wide study of haplotypes with samples consisting of African-Americans and samples consisting of Japanese and Chinese individuals. For both populations, we have found that the sample size and marker set have significant impact on the number of blocks and the total number of representative markers identified. The marker set in particular has very strong impacts, and our results indicate that the marker density in the original datasets may not be adequate to allow a meaningful characterisation of haplotype structures. In general, we conclude that we need a relatively large sample size and a very dense marker panel in the study of haplotype structures in human populations.

  4. Metal-organic framework based in-syringe solid-phase extraction for the on-site sampling of polycyclic aromatic hydrocarbons from environmental water samples.

    Science.gov (United States)

    Zhang, Xiaoqiong; Wang, Peiyi; Han, Qiang; Li, Hengzhen; Wang, Tong; Ding, Mingyu

    2018-04-01

    In-syringe solid-phase extraction is a promising sample pretreatment method for the on-site sampling of water samples because of its outstanding advantages of portability, simple operation, short extraction time, and low cost. In this work, a novel in-syringe solid-phase extraction device using metal-organic frameworks as the adsorbent was fabricated for the on-site sampling of polycyclic aromatic hydrocarbons from environmental waters. Trace polycyclic aromatic hydrocarbons were effectively extracted through the self-made device followed by gas chromatography with mass spectrometry analysis. Owing to the excellent adsorption performance of metal-organic frameworks, the analytes could be completely adsorbed during one adsorption cycle, thus effectively shortening the extraction time. Moreover, the adsorbed analytes could remain stable on the device for at least 7 days, revealing the potential of the self-made device for on-site sampling of degradable compounds in remote regions. The limit of detection ranged from 0.20 to 1.9 ng/L under the optimum conditions. Satisfactory recoveries varying from 84.4 to 104.5% and relative standard deviations below 9.7% were obtained in real samples analysis. The results of this study promote the application of metal-organic frameworks in sample preparation and demonstrate the great potential of in-syringe solid-phase extraction for the on-site sampling of trace contaminants in environmental waters. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Using Environmental Variables for Studying of the Quality of Sampling in Soil Mapping

    Directory of Open Access Journals (Sweden)

    A. Jafari

    2016-02-01

    Full Text Available Introduction: Methods of soil survey are generally empirical and based on the mental development of the surveyor, correlating soil with underlying geology, landforms, vegetation and air-photo interpretation. Since there are no statistical criteria for traditional soil sampling; this may lead to bias in the areas being sampled. In digital soil mapping, soil samples may be used to elaborate quantitative relationships or models between soil attributes and soil covariates. Because the relationships are based on the soil observations, the quality of the resulting soil map depends also on the soil observation quality. An appropriate sampling design for digital soil mapping depends on how much data is available and where the data is located. Some statistical methods have been developed for optimizing data sampling for soil surveys. Some of these methods deal with the use of ancillary information. The purpose of this study was to evaluate the quality of sampling of existing data. Materials and Methods: The study area is located in the central basin of the Iranian plateau (Figure 1. The geologic infrastructure of the area is mainly Cretaceous limestone, Mesozoic shale and sandstone. Air photo interpretation (API was used to differentiate geomorphic patterns based on their formation processes, general structure and morphometry. The patterns were differentiated through a nested geomorphic hierarchy (Fig. 2. A four-level geomorphic hierarchy is used to breakdown the complexity of different landscapes of the study area. In the lower level of the hierarchy, the geomorphic surfaces, which were formed by a unique process during a specific geologic time, were defined. A stratified sampling scheme was designed based on geomorphic mapping. In the stratified simple random sampling, the area was divided into sub-areas referred to as strata based on geomorphic surfaces, and within each stratum, sampling locations were randomly selected (Figure 2. This resulted in 191

  6. Experimental Study and Mathematical Modeling of Asphaltene Deposition Mechanism in Core Samples

    Directory of Open Access Journals (Sweden)

    Jafari Behbahani T.

    2015-11-01

    Full Text Available In this work, experimental studies were conducted to determine the effect of asphaltene deposition on the permeability reduction and porosity reduction of carbonate, sandstone and dolomite rock samples using an Iranian bottom hole live oil sample which is close to reservoir conditions, whereas in the majority of previous work, a mixture of recombined oil (a mixture of dead oil and associated gas was injected into a core sample which is far from reservoir conditions. The effect of the oil injection rate on asphaltene deposition and permeability reduction was studied. The experimental results showed that an increase in the oil injection flow rate can result in an increase in asphaltene deposition and permeability reduction. Also, it can be observed that at lower injection flow rates, a monotonic decrease in permeability of the rock samples can be attained upon increasing the injection flow rate, while at higher injection rates, after a decrease in rock permeability, an increasing trend is observed before a steady-state condition can be reached. The experimental results also showed that the rock type can affect the amount of asphaltene deposition, and the asphaltene deposition has different mechanisms in sandstone and carbonate core samples. It can be seen that the adsorption and plugging mechanisms have a more important role in asphaltene deposition in carbonate core samples than sandstone core samples. From the results, it can be observed that the pore volumes of the injected crude oil are higher for sandstone cores compared with the carbonate cores. Also, it can be inferred that three depositional types may take place during the crude oil injection, i.e., continuous deposition for low-permeability cores, slow, steady plugging for high-permeability cores and steady deposition for medium-permeability cores. It can be seen from the experimental results that damage to the core samples was found to increase when the production pressures were

  7. Study population, questionnaire, data management and sample description

    Directory of Open Access Journals (Sweden)

    Chiara de Waure

    2015-06-01

    Full Text Available INTRODUCTION: This article describes methodological issues of the "Sportello Salute Giovani" project ("Youth Health Information Desk", a multicenter study aimed at assessing the health status and attitudes and behaviours of university students in Italy. MATERIALS AND METHODS: The questionnaire used to carry out the study was adapted from the Italian health behaviours in school-aged children (HBSC project and consisted of 93 items addressing: demographics; nutritional habits and status; physical activity; lifestyles; reproductive and preconception health; health and satisfaction of life; attitudes and behaviours toward academic study and new technologies. The questionnaire was administered to a pool of 12 000 students from 18 to 30 years of age who voluntary decided to participate during classes held at different Italian faculties or at the three "Sportello Salute Giovani" centers which were established in the three sites of the Università Cattolica del Sacro Cuore (Catholic University of the Sacred Heart of Rome. RESULTS: The final study sample was composed by 8516 university students. The mean age of responders was 22.2 (Standard Deviation 2.0 and 5702 (67.0% were females. According to the distribution in age classes, 3601 (43.3% belonged to the 18-21 one, 3796 (44.5% to the 22-24 class and 1019 (12.2% to the 25-30 class. With respect to socio-economic status, data were available for 8410 responders and showed that 50.3% of students belonged to the middle class. DISCUSSION: The project took into consideration a large number of individuals from different regions of the country and therefore may be considered representative of the general population of Italian university students. Furthermore, it is the first to address, at the same time, several issues, in particular attitudes and behaviours toward health, in Italian university students. CONCLUSION: The analysis of data from such a large sample of university students sets the basis for

  8. DNA damage focus analysis in blood samples of minipigs reveals acute partial body irradiation.

    Directory of Open Access Journals (Sweden)

    Andreas Lamkowski

    Full Text Available Radiation accidents frequently involve acute high dose partial body irradiation leading to victims with radiation sickness and cutaneous radiation syndrome that implements radiation-induced cell death. Cells that are not lethally hit seek to repair ionizing radiation (IR induced damage, albeit at the expense of an increased risk of mutation and tumor formation due to misrepair of IR-induced DNA double strand breaks (DSBs. The response to DNA damage includes phosphorylation of histone H2AX in the vicinity of DSBs, creating foci in the nucleus whose enumeration can serve as a radiation biodosimeter. Here, we investigated γH2AX and DNA repair foci in peripheral blood lymphocytes of Göttingen minipigs that experienced acute partial body irradiation (PBI with 49 Gy (± 6% Co-60 γ-rays of the upper lumbar region. Blood samples taken 4, 24 and 168 hours post PBI were subjected to γ-H2AX, 53BP1 and MRE11 focus enumeration. Peripheral blood lymphocytes (PBL of 49 Gy partial body irradiated minipigs were found to display 1-8 DNA damage foci/cell. These PBL values significantly deceed the high foci numbers observed in keratinocyte nuclei of the directly γ-irradiated minipig skin regions, indicating a limited resident time of PBL in the exposed tissue volume. Nonetheless, PBL samples obtained 4 h post IR in average contained 2.2% of cells displaying a pan-γH2AX signal, suggesting that these received a higher IR dose. Moreover, dispersion analysis indicated partial body irradiation for all 13 minipigs at 4 h post IR. While dose reconstruction using γH2AX DNA repair foci in lymphocytes after in vivo PBI represents a challenge, the DNA damage focus assay may serve as a rapid, first line indicator of radiation exposure. The occurrence of PBLs with pan-γH2AX staining and of cells with relatively high foci numbers that skew a Poisson distribution may be taken as indicator of acute high dose partial body irradiation, particularly when samples are available

  9. Breeding snow: an instrumented sample holder for simultaneous tomographic and thermal studies

    International Nuclear Information System (INIS)

    Pinzer, B; Schneebeli, M

    2009-01-01

    To study the recrystallization processes during temperature gradient metamorphism of snow, we developed a sample holder that allows applying well-defined and stable thermal gradients to a snow sample while it is scanned in an x-ray micro-tomograph. To this end, both the thermal insulation of the sample as well as image contrast and resolution of the tomography had to be optimized. We solved this conflict by using thin aluminum cylinders in combination with highly insulating foam. This design is light, does not corrupt image quality and provides very good thermal decoupling from the environment. The sample holder was instrumented to measure the effective conductivity of the snow sample and calibrated using five materials of known conductivity. Finite element simulations were consistent with the calibration measurements and gave insight into the internal temperature and heat flux fields. With this setup, geometric and thermal evolution of snow under realistic thermal boundary conditions like alternating temperature gradients can be measured

  10. Abortion experiences among Zanzibari women: a chain-referral sampling study.

    Science.gov (United States)

    Norris, Alison; Harrington, Bryna J; Grossman, Daniel; Hemed, Maryam; Hindin, Michelle J

    2016-03-11

    In Zanzibar, a semi-autonomous region of Tanzania, induced abortion is illegal but common, and fewer than 12% of married reproductive-aged women use modern contraception. As part of a multi-method study about contraception and consequences of unwanted pregnancies, the objective of this study was to understand the experiences of Zanzibari women who terminated pregnancies. The cross-sectional study was set in Zanzibar, Tanzania. Participants were a community-based sample of women who had terminated pregnancies. We carried out semi-structured interviews with 45 women recruited via chain-referral sampling. We report the characteristics of women who have had abortions, the reasons they had abortions, and the methods used to terminate their pregnancies. Women in Zanzibar terminate pregnancies that are unwanted for a range of reasons, at various points in their reproductive lives, and using multiple methods. While clinical methods were most effective, nearly half of our participants successfully terminated a pregnancy using non-clinical methods and very few had complications requiring post abortion care (PAC). Even in settings where abortion is illegal, some women experience illegal abortions without adverse health consequences, what we might call 'safer' unsafe abortions; these kinds of abortion experiences can be missed in studies about abortion conducted among women seeking PAC in hospitals.

  11. Statistical methods for detecting differentially abundant features in clinical metagenomic samples.

    Directory of Open Access Journals (Sweden)

    James Robert White

    2009-04-01

    Full Text Available Numerous studies are currently underway to characterize the microbial communities inhabiting our world. These studies aim to dramatically expand our understanding of the microbial biosphere and, more importantly, hope to reveal the secrets of the complex symbiotic relationship between us and our commensal bacterial microflora. An important prerequisite for such discoveries are computational tools that are able to rapidly and accurately compare large datasets generated from complex bacterial communities to identify features that distinguish them.We present a statistical method for comparing clinical metagenomic samples from two treatment populations on the basis of count data (e.g. as obtained through sequencing to detect differentially abundant features. Our method, Metastats, employs the false discovery rate to improve specificity in high-complexity environments, and separately handles sparsely-sampled features using Fisher's exact test. Under a variety of simulations, we show that Metastats performs well compared to previously used methods, and significantly outperforms other methods for features with sparse counts. We demonstrate the utility of our method on several datasets including a 16S rRNA survey of obese and lean human gut microbiomes, COG functional profiles of infant and mature gut microbiomes, and bacterial and viral metabolic subsystem data inferred from random sequencing of 85 metagenomes. The application of our method to the obesity dataset reveals differences between obese and lean subjects not reported in the original study. For the COG and subsystem datasets, we provide the first statistically rigorous assessment of the differences between these populations. The methods described in this paper are the first to address clinical metagenomic datasets comprising samples from multiple subjects. Our methods are robust across datasets of varied complexity and sampling level. While designed for metagenomic applications, our software

  12. Sample holder for studying temperature dependent particle guiding

    International Nuclear Information System (INIS)

    Bereczky, R.J.; Toekesi, K.; Kowarik, G.; Aumayr, F.

    2011-01-01

    Complete text of publication follows. The so called guiding effect is a complex process involving the interplay of a large number of charged particles with a solid. Although many research groups joined this field and carried out various experiments with insulator capillaries many details of the interactions are still unknown. We investigated the temperature dependence of the guiding since it opens new possibilities both for a fundamental understanding of the guiding phenomenon and for applications. For the temperature dependent guiding experiments a completely new heatable sample holder was designed. We developed and built such a heatable sample holder to make accurate and reproducible studies of the temperature dependence of the ion guiding effect possible. The target holder (for an exploded view see Fig. 1) consists of two main parts, the front and the back plates. The two plates of the sample holder, which function as an oven, are made of copper. These parts surround the capillary in order to guarantee a uniform temperature along the whole tube. The temperature of the copper parts is monitored by a K-Type thermocouple. Stainless steel coaxial heaters surrounding the oven are used for heating. The heating power up to a few watts is regulated by a PID controller. Cooling of the capillary is achieved by a copper feed-through connected to a liquid nitrogen bath outside the UHV chamber. This solution allows us to change the temperature of the sample from -30 deg C up to 90 deg C. Our experiments with this newly developed temperature regulated capillary holder show that the glass temperature (i.e. conductivity) can be used to control the guiding properties of the glass capillary and adjust the conditions from guiding at room temperature to simple geometrical transmission at elevated temperatures. This holds the promise to investigate the effect of conductivity on particle transport (build-up and removal of charge patches) through capillaries in more details

  13. Effect of measurement error budgets and hybrid metrology on qualification metrology sampling

    Science.gov (United States)

    Sendelbach, Matthew; Sarig, Niv; Wakamoto, Koichi; Kim, Hyang Kyun (Helen); Isbester, Paul; Asano, Masafumi; Matsuki, Kazuto; Osorio, Carmen; Archie, Chas

    2014-10-01

    Until now, metrologists had no statistics-based method to determine the sampling needed for an experiment before the start that accuracy experiment. We show a solution to this problem called inverse total measurement uncertainty (TMU) analysis, by presenting statistically based equations that allow the user to estimate the needed sampling after providing appropriate inputs, allowing him to make important "risk versus reward" sampling, cost, and equipment decisions. Application examples using experimental data from scatterometry and critical dimension scanning electron microscope tools are used first to demonstrate how the inverse TMU analysis methodology can be used to make intelligent sampling decisions and then to reveal why low sampling can lead to unstable and misleading results. One model is developed that can help experimenters minimize sampling costs. A second cost model reveals the inadequacy of some current sampling practices-and the enormous costs associated with sampling that provides reasonable levels of certainty in the result. We introduce the strategies on how to manage and mitigate these costs and begin the discussion on how fabs are able to manufacture devices using minimal reference sampling when qualifying metrology steps. Finally, the relationship between inverse TMU analysis and hybrid metrology is explored.

  14. The microbiome of Brazilian mangrove sediments as revealed by metagenomics

    NARCIS (Netherlands)

    Andreote, Fernando Dini; Jiménez Avella, Diego; Chaves, Diego; Dias, Armando Cavalcante Franco; Luvizotto, Danice Mazzer; Dini-Andreote, Francisco; Fasanella, Cristiane Cipola; Lopez, Maryeimy Varon; Baena, Sandra; Taketani, Rodrigo Gouvêa; de Melo, Itamar Soares

    2012-01-01

    Here we embark in a deep metagenomic survey that revealed the taxonomic and potential metabolic pathways aspects of mangrove sediment microbiology. The extraction of DNA from sediment samples and the direct application of pyrosequencing resulted in approximately 215 Mb of data from four distinct

  15. Comprehensive study of unexpected microscope condensers formed in sample arrangements commonly used in optical microscopy.

    Science.gov (United States)

    Desai, Darshan B; Aldawsari, Mabkhoot Mudith S; Alharbi, Bandar Mohammed H; Sen, Sanchari; Grave de Peralta, Luis

    2015-09-01

    We show that various setups for optical microscopy which are commonly used in biomedical laboratories behave like efficient microscope condensers that are responsible for observed subwavelength resolution. We present a series of experiments and simulations that reveal how inclined illumination from such unexpected condensers occurs when the sample is perpendicularly illuminated by a microscope's built-in white-light source. In addition, we demonstrate an inexpensive add-on optical module that serves as an efficient and lightweight microscope condenser. Using such add-on optical module in combination with a low-numerical-aperture objective lens and Fourier plane imaging microscopy technique, we demonstrate detection of photonic crystals with a period nearly eight times smaller than the Rayleigh resolution limit.

  16. A study on aluminum determination in environmental samples by Neutron Activation Analysis

    International Nuclear Information System (INIS)

    Noyori, Amanda

    2017-01-01

    Aluminum determinations are of great interest since this element is toxic to humans and it is widely distributed in the environment. Besides, the determinations of this element by conventional analytical methods present difficulties due to sample contamination during the analyses. Neutron activation analysis (NAA) for Al determination presents advantages of fast analyses and of high sensitivity. However, NAA of Al does present problems of P and Si nuclear reaction interferences. Aluminum is determined by measuring 28 Al, formed in the reaction 27 Al (n, γ) 28 Al, the same radioisotope formed in reactions 31 P (n, α) 28 Al and 28 Si (n, p) 28 Al. The purpose of this study was to determine Al in environmental samples by NAA correcting these interferences using correction factors, and determining P and Si concentrations in the samples. In this study, certified reference materials and biomonitor samples (tree barks and lichen) were analyzed. Experimental procedure consisted of irradiating an aliquot of the sample at the IEA-R1 nuclear research reactor together with Al standard, followed by gamma ray spectrometry. Phosphorus was determined by measuring beta radiation of 32 P using a Geiger-Müller counter. Silicon was determined by epithermal neutron activation analysis and measuring 29 Al formed in the reaction 29 Si (n, p) 29 Al. Results obtained in the determination of Al, P and Si in the certified reference materials showed good precision and accuracy with |Z-score| ≤ 2. Aluminum results in the biomonitor samples varied from to 253 to 15783 μg g -1 . In the case of P its concentrations varied from 283 to 1946 μg g -1 . Silicon determinations in biomonitors varied from 0.11 to 7.8 %. The interference contribution rates in the analyses of the biomonitor samples were of the order of 2.0 % and this contribution depends on the relation between concentrations of interfering elements and of Al in the sample. Detection limit values of Al in the biomonitor analyses

  17. Laboratory Studies on Surface Sampling of Bacillus anthracis Contamination: Summary, Gaps, and Recommendations

    Energy Technology Data Exchange (ETDEWEB)

    Piepel, Gregory F.; Amidan, Brett G.; Hu, Rebecca

    2011-11-28

    This report summarizes previous laboratory studies to characterize the performance of methods for collecting, storing/transporting, processing, and analyzing samples from surfaces contaminated by Bacillus anthracis or related surrogates. The focus is on plate culture and count estimates of surface contamination for swab, wipe, and vacuum samples of porous and nonporous surfaces. Summaries of the previous studies and their results were assessed to identify gaps in information needed as inputs to calculate key parameters critical to risk management in biothreat incidents. One key parameter is the number of samples needed to make characterization or clearance decisions with specified statistical confidence. Other key parameters include the ability to calculate, following contamination incidents, the (1) estimates of Bacillus anthracis contamination, as well as the bias and uncertainties in the estimates, and (2) confidence in characterization and clearance decisions for contaminated or decontaminated buildings. Gaps in knowledge and understanding identified during the summary of the studies are discussed and recommendations are given for future studies.

  18. Study on infrasonic characteristics of coal samples in failure process under uniaxial loading

    Directory of Open Access Journals (Sweden)

    Bing Jia

    Full Text Available To study the precursory failure infrasonic characteristics of coal samples, coal rock stress loading system and infrasonic wave acquisition system were adopted, and infrasonic tests in uniaxial loading process were made for the coal samples in the studied area. Wavelet filtering, fast Fourier transform, and relative infrasonic energy methods were used to analyze the characteristics of the infrasonic waves in the loading process, including time domain characteristics, and relative energy. The analysis results demonstrated that the frequencies of the infrasonic signals in the loading process mainly distribute within 5–10 Hz, which are significantly different from noise signals. The changes of the infrasonic signals show clear periodic characters in time domain. Meanwhile, the relative energy changes of the infrasonic wave also show periodic characters, which are divided into two stages by the yield limit of coal samples, and are clear and easy to be recognized, so that they can be used as the precursory characteristics for recognizing coal sample failures. Moreover, the infrasonic waves generated by coal samples have low frequency and low attenuation, which can be collected without coupling and transmitted in long distance. This study provides an important support for the further in-situ prediction of coal rock failures. Keywords: Infrasound, Relative energy, Time-frequency analysis, Failure prediction, Identification feature

  19. Micro-PIXE evaluation of radioactive cesium transfer in contaminated soil samples

    International Nuclear Information System (INIS)

    Fujishiro, F.; Ishii, K.; Matsuyama, S.; Arai, H.; Ishizaki, A.; Osada, N.; Sugai, H.; Kusano, K.; Nozawa, Y.; Yamauchi, S.; Karahashi, M.; Oshikawa, S.; Kikuchi, K.; Koshio, S.; Watanabe, K.; Suzuki, Y.

    2014-01-01

    Highlights: • There are radioactively contaminated soils having a radioactive cesium transfer of 0.01. • Micro-PIXE analysis has revealed an existence of phosphorus in a contaminated soil. • Radioactive cesium captured by phosphorus compound would be due to radioactive transfer. -- Abstract: Micro-PIXE analysis has been performed on two soil samples with high cesium activity concentrations. These soil samples were contaminated by fallout from the accident at Fukushima Daiichi Nuclear Power Plant. One exhibits a radioactive cesium transfer of ∼0.01, and the other shows a radioactive cesium transfer of less than 0.001, even though both samples have high cesium activity concentrations exceeding 10,000 Bq/kg. X-ray spectra and elemental images of the soil samples revealed the presence of chlorine, which can react with cesium to produce an inorganic soluble compound, and phosphorus-containing cesium-capturable organic compounds

  20. Fine-scale genetic structure and cryptic associations reveal evidence of kin-based sociality in the African forest elephant.

    Science.gov (United States)

    Schuttler, Stephanie G; Philbrick, Jessica A; Jeffery, Kathryn J; Eggert, Lori S

    2014-01-01

    Spatial patterns of relatedness within animal populations are important in the evolution of mating and social systems, and have the potential to reveal information on species that are difficult to observe in the wild. This study examines the fine-scale genetic structure and connectivity of groups within African forest elephants, Loxodonta cyclotis, which are often difficult to observe due to forest habitat. We tested the hypothesis that genetic similarity will decline with increasing geographic distance, as we expect kin to be in closer proximity, using spatial autocorrelation analyses and Tau K(r) tests. Associations between individuals were investigated through a non-invasive genetic capture-recapture approach using network models, and were predicted to be more extensive than the small groups found in observational studies, similar to fission-fusion sociality found in African savanna (Loxodonta africana) and Asian (Elephas maximus) species. Dung samples were collected in Lopé National Park, Gabon in 2008 and 2010 and genotyped at 10 microsatellite loci, genetically sexed, and sequenced at the mitochondrial DNA control region. We conducted analyses on samples collected at three different temporal scales: a day, within six-day sampling sessions, and within each year. Spatial autocorrelation and Tau K(r) tests revealed genetic structure, but results were weak and inconsistent between sampling sessions. Positive spatial autocorrelation was found in distance classes of 0-5 km, and was strongest for the single day session. Despite weak genetic structure, individuals within groups were significantly more related to each other than to individuals between groups. Social networks revealed some components to have large, extensive groups of up to 22 individuals, and most groups were composed of individuals of the same matriline. Although fine-scale population genetic structure was weak, forest elephants are typically found in groups consisting of kin and based on matrilines

  1. Amostragem de solo para estudos de fertilidade Sampling soils for fertility studies

    Directory of Open Access Journals (Sweden)

    R. A. Catani

    1955-01-01

    Full Text Available O presente trabalho foi realizado com a finalidade de estabelecer um sistema e técnica mais adequados de se coletar amostras de terra, para fins de estudo de fertilidade. Foram escolhidas duas áreas de solos diferentes. Uma delas com seis hectares, situada na Estação Experimental de Ribeirão Prêto, em solo tipo terra roxa legítima ; a outra com quatro hectares e localizada na Fazenda Santa Maria, em Pindorama, em solo do tipo arenito Bauru. A retirada das amostras de cada área foi feita com tubos especialmente construídos para esse fim e obedeceu ao seguinte critério: 1 30 amostras simples, cobrindo tôda a área ; 2 10 amostras compostas, formadas de cinco amostras simples, cobrindo tôda a área. 3 5 amostras compostas, formadas de 20 amostras simples, cobrindo tôda a área. Nessas amostras foram determinados : pH, carbono total, potássio "trocável" e cálcio "trocável". Diante dos dados obtidos e levando-se em conta o trabalho exigido no laboratório, aconselha-se a retirada de três amostras compostas formadas de 20 simples cada uma, em glebas uniformes, de cinco hectares aproximadamente.The following methods of collecting soil samples for fertility studies were compared : 1 thirty individual samples covering the whole area ; 2 ten composite samples, each consisting of five individual samples, covering the whole area ; 3 five composite samples, each consisting of 20 individual samples, covering the whole area. The three types of samples were collected in each of two plots : 1 a six-hectare plot in the Estação Experimental de Ribeirão Prêto, representing the "terra roxa" soil; 2 a four-hectare plot in the Santa Maria Farm, Pindorama, where the soil is of the "arenito de Bauru" type. The pH, total carbon, and exchangeable potassium and calcium were determined in the samples. Based on data obtained in the present investigation and considering the amount of work involved in the routine laboratory tests, it is suggested that

  2. Sample normalization methods in quantitative metabolomics.

    Science.gov (United States)

    Wu, Yiman; Li, Liang

    2016-01-22

    To reveal metabolomic changes caused by a biological event in quantitative metabolomics, it is critical to use an analytical tool that can perform accurate and precise quantification to examine the true concentration differences of individual metabolites found in different samples. A number of steps are involved in metabolomic analysis including pre-analytical work (e.g., sample collection and storage), analytical work (e.g., sample analysis) and data analysis (e.g., feature extraction and quantification). Each one of them can influence the quantitative results significantly and thus should be performed with great care. Among them, the total sample amount or concentration of metabolites can be significantly different from one sample to another. Thus, it is critical to reduce or eliminate the effect of total sample amount variation on quantification of individual metabolites. In this review, we describe the importance of sample normalization in the analytical workflow with a focus on mass spectrometry (MS)-based platforms, discuss a number of methods recently reported in the literature and comment on their applicability in real world metabolomics applications. Sample normalization has been sometimes ignored in metabolomics, partially due to the lack of a convenient means of performing sample normalization. We show that several methods are now available and sample normalization should be performed in quantitative metabolomics where the analyzed samples have significant variations in total sample amounts. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. DNA methylation analysis from saliva samples for epidemiological studies.

    Science.gov (United States)

    Nishitani, Shota; Parets, Sasha E; Haas, Brian W; Smith, Alicia K

    2018-06-18

    Saliva is a non-invasive, easily accessible tissue, which is regularly collected in large epidemiological studies to examine genetic questions. Recently, it is becoming more common to use saliva to assess DNA methylation. However, DNA extracted from saliva is a mixture of both bacterial and human DNA derived from epithelial and immune cells in the mouth. Thus, there are unique challenges to using salivary DNA in methylation studies that can influence data quality. This study assesses: (1) quantification of human DNA after extraction; (2) delineation of human and bacterial DNA; (3) bisulfite conversion (BSC); (4) quantification of BSC DNA; (5) PCR amplification of BSC DNA from saliva and; (6) quantitation of DNA methylation with a targeted assay. The framework proposed will allow saliva samples to be more widely used in targeted epigenetic studies.

  4. Study on auto-plating process time versus recovery for polonium, Po-210 in environmental sample

    International Nuclear Information System (INIS)

    Jalal Sharib; Zaharudin Ahmad; Abdul Kadir Ishak; Norfaizal Mohamed; Ahmad Sanadi Abu Bakar; Yii Mei Wo; Kamarozaman Ishak; Siti Aminah Yusoff

    2008-08-01

    This study was carried out to evaluate time effectiveness and recovery 16 samples of 4 Kuala Muda stations during auto-plating process procedures for determination Polonium, Po 210 activity concentration in environmental sample. The study was performed using Kuala Muda sediment as sample in the same methodology. The auto-plating process runs for 4, 12, 24 and 30 hours on a silver disc for 4 samples each station, and then counted for one (1) day using an alpha spectrometry counting system. The objectives for this study is to justify on time duration for auto-plating process effecting a chemical yield of Po-209.The results showed recovery are increasing versus time and constantly at 24 hour auto-plating. Its mean, 24 hour is an optimum time for auto-plating process for determination of Polonium, Po 210 activity concentration in environmental sample. (Author)

  5. A bioassay for the detection of benzimidazoles reveals their presence in a range of environmental samples

    Directory of Open Access Journals (Sweden)

    Terence S Crofts

    2014-11-01

    Full Text Available Cobamides are a family of enzyme cofactors that include vitamin B12 (cobalamin and are produced solely by prokaryotes. Structural variability in the lower axial ligand has been observed in cobamides produced by diverse organisms. Of the three classes of lower ligands, the benzimidazoles are uniquely found in cobamides, whereas the purine and phenolic bases have additional biological functions. Many organisms acquire cobamides by salvaging and remodeling cobamides or their precursors from the environment. These processes require free benzimidazoles for incorporation as lower ligands, though the presence of benzimidazoles in the environment has not been previously investigated. Here, we report a new purification method and bioassay to measure the total free benzimidazole content of samples from microbial communities and laboratory media components. The bioassay relies on the calcofluor-bright phenotype of a bluB mutant of the model cobalamin-producing bacterium Sinorhizobium meliloti. The concentrations of individual benzimidazoles in these samples were measured by liquid chromatography-tandem mass spectrometry. Several benzimidazoles were detected in subpicomolar to subnanomolar concentrations in host-associated and environmental samples. In addition, benzimidazoles were found to be common contaminants of laboratory media components. These results suggest that benzimidazoles present in the environment and in laboratory media have the potential to influence microbial metabolic activities.

  6. Defining And Characterizing Sample Representativeness For DWPF Melter Feed Samples

    Energy Technology Data Exchange (ETDEWEB)

    Shine, E. P.; Poirier, M. R.

    2013-10-29

    Representative sampling is important throughout the Defense Waste Processing Facility (DWPF) process, and the demonstrated success of the DWPF process to achieve glass product quality over the past two decades is a direct result of the quality of information obtained from the process. The objective of this report was to present sampling methods that the Savannah River Site (SRS) used to qualify waste being dispositioned at the DWPF. The goal was to emphasize the methodology, not a list of outcomes from those studies. This methodology includes proven methods for taking representative samples, the use of controlled analytical methods, and data interpretation and reporting that considers the uncertainty of all error sources. Numerous sampling studies were conducted during the development of the DWPF process and still continue to be performed in order to evaluate options for process improvement. Study designs were based on use of statistical tools applicable to the determination of uncertainties associated with the data needs. Successful designs are apt to be repeated, so this report chose only to include prototypic case studies that typify the characteristics of frequently used designs. Case studies have been presented for studying in-tank homogeneity, evaluating the suitability of sampler systems, determining factors that affect mixing and sampling, comparing the final waste glass product chemical composition and durability to that of the glass pour stream sample and other samples from process vessels, and assessing the uniformity of the chemical composition in the waste glass product. Many of these studies efficiently addressed more than one of these areas of concern associated with demonstrating sample representativeness and provide examples of statistical tools in use for DWPF. The time when many of these designs were implemented was in an age when the sampling ideas of Pierre Gy were not as widespread as they are today. Nonetheless, the engineers and

  7. Defining And Characterizing Sample Representativeness For DWPF Melter Feed Samples

    International Nuclear Information System (INIS)

    Shine, E. P.; Poirier, M. R.

    2013-01-01

    Representative sampling is important throughout the Defense Waste Processing Facility (DWPF) process, and the demonstrated success of the DWPF process to achieve glass product quality over the past two decades is a direct result of the quality of information obtained from the process. The objective of this report was to present sampling methods that the Savannah River Site (SRS) used to qualify waste being dispositioned at the DWPF. The goal was to emphasize the methodology, not a list of outcomes from those studies. This methodology includes proven methods for taking representative samples, the use of controlled analytical methods, and data interpretation and reporting that considers the uncertainty of all error sources. Numerous sampling studies were conducted during the development of the DWPF process and still continue to be performed in order to evaluate options for process improvement. Study designs were based on use of statistical tools applicable to the determination of uncertainties associated with the data needs. Successful designs are apt to be repeated, so this report chose only to include prototypic case studies that typify the characteristics of frequently used designs. Case studies have been presented for studying in-tank homogeneity, evaluating the suitability of sampler systems, determining factors that affect mixing and sampling, comparing the final waste glass product chemical composition and durability to that of the glass pour stream sample and other samples from process vessels, and assessing the uniformity of the chemical composition in the waste glass product. Many of these studies efficiently addressed more than one of these areas of concern associated with demonstrating sample representativeness and provide examples of statistical tools in use for DWPF. The time when many of these designs were implemented was in an age when the sampling ideas of Pierre Gy were not as widespread as they are today. Nonetheless, the engineers and

  8. Accurate and High-Coverage Immune Repertoire Sequencing Reveals Characteristics of Antibody Repertoire Diversification in Young Children with Malaria

    Science.gov (United States)

    Jiang, Ning

    Accurately measuring the immune repertoire sequence composition, diversity, and abundance is important in studying repertoire response in infections, vaccinations, and cancer immunology. Using molecular identifiers (MIDs) to tag mRNA molecules is an effective method in improving the accuracy of immune repertoire sequencing (IR-seq). However, it is still difficult to use IR-seq on small amount of clinical samples to achieve a high coverage of the repertoire diversities. This is especially challenging in studying infections and vaccinations where B cell subpopulations with fewer cells, such as memory B cells or plasmablasts, are often of great interest to study somatic mutation patterns and diversity changes. Here, we describe an approach of IR-seq based on the use of MIDs in combination with a clustering method that can reveal more than 80% of the antibody diversity in a sample and can be applied to as few as 1,000 B cells. We applied this to study the antibody repertoires of young children before and during an acute malaria infection. We discovered unexpectedly high levels of somatic hypermutation (SHM) in infants and revealed characteristics of antibody repertoire development in young children that would have a profound impact on immunization in children.

  9. Study of Zn/Cu ratio and oligoelements in serum samples for cancer diagnosis

    International Nuclear Information System (INIS)

    Lue-Meru, M. P.; Jimenez, E.; Hernandez, E.; Rojas, A.; Greaves, E.

    2000-01-01

    The aim of this work was to study methods for cancer diagnosis based on trace element determination in serum blood samples. TXRF technique was selected for the analysis, due to its simultaneous and multi-elemental character, the very small amount of sample required and the high sensitivity. For the study, blood samples were collected from normal individuals (Blood donors and students), classified by age and sex in order to obtain reference normal values for the elements Zn, Cu, Fe, Mn, Se, and additionally, Ca and K. Samples from cancer patients before treatment and under treatment were collected at the oncological Service (BADAN-Lara), and were also classified by age and sex. The TXRF procedure used was developed in a previous work and involves the direct analysis and the use of Compton peak as Internal Standard. All the samples were analyzed by the routine clinical test (blood chemistry). Elemental concentrations and clinical data were processed with the statistical package Minitab-Windows, in order to establish the respective correlation. Concerning to elemental concentrations, significant differences were found in Zn/Cu ratio between normal individuals group and the cancer patients group. (author)

  10. THE STUDY OF HEAVY METAL FROM ENVIRONMENTAL SAMPLES BY ATOMIC TECHNIQUES

    Directory of Open Access Journals (Sweden)

    Ion V. POPESCU

    2011-05-01

    Full Text Available Using the Atomic Absorption Spectrometry (AAS and Energy Dispersive X-ray spectrometry (EDXRF techniques we analyzed the contents of heavy metals ( Cd, Cr, Ni, Pb, Ti, Sr, Co, Bi from eight wild mushrooms and soil substrate samples (48 samples of eight fungal species and 32 underlying soil samples, collected from ten forest sites of Dambovița County Romania. It was determined that the elements, especially heavy metals, in soil were characteristic of the acidic soils of the Romanian forest lands and are influenced by industrial pollution. Analytical possibilities of AAS and EDXRF analytical techniques have been compared and the heavy metal transfer from substrate to mushrooms has been studied. The coefficient of accumulation of essential and heavy metals has been calculated as well. Heavy metal contents of all analyzed mushrooms were generally higher than previously reported in literature.

  11. Study on natural radioactive elements in soil and rock samples around Mandya district, India

    International Nuclear Information System (INIS)

    Shivakumara, B.C.; Paramesh, L.; Shashikumar, T.S.; Chandrashekara, M.S.

    2012-01-01

    The soil is a complex mixture of different compounds and rocks. In the natural environment, it is an important source of exposure to radiation due to naturally occurring, gamma emitting radionuclides which include 226 Ra, 232 Th and 40 K present in the soil. The study of distribution of these radionuclides in soil and rock is of great importance for radiation protection and measurements. The activity concentrations of 226 Ra, 232 Th, and 40 K in soil and rock samples collected in Mandya District, Karnataka state, India have been measured by gamma ray spectrometry. The average activity concentrations of 226 Ra, 232 Th, and 40 K (Bq/kg) are found to be 40.2, 62.3, and 317.5 Bq/kg, respectively, in soil samples and 30.5, 34.4, and 700.2 Bq/kg, respectively, in rock samples. The concentrations of radionuclides in soil samples are found to higher than in rock samples. The concentrations of radionuclides in soil and rock samples in the study area are slightly higher than Indian average and world average values. (author)

  12. Genetic characterization of Toxoplasma gondii from Brazilian wildlife revealed abundant new genotypes.

    Science.gov (United States)

    Vitaliano, S N; Soares, H S; Minervino, A H H; Santos, A L Q; Werther, K; Marvulo, M F V; Siqueira, D B; Pena, H F J; Soares, R M; Su, C; Gennari, S M

    2014-12-01

    This study aimed to isolate and genotype T. gondii from Brazilian wildlife. For this purpose, 226 samples were submitted to mice bioassay and screened by PCR based on 18S rRNA sequences. A total of 15 T. gondii isolates were obtained, including samples from four armadillos (three Dasypus novemcinctus, one Euphractus sexcinctus), three collared anteaters (Tamandua tetradactyla), three whited-lipped peccaries (Tayassu pecari), one spotted paca (Cuniculus paca), one oncilla (Leopardus tigrinus), one hoary fox (Pseudalopex vetulus), one lineated woodpecker (Dryocopus lineatus) and one maned wolf (Chrysocyon brachyurus). DNA from the isolates, originated from mice bioassay, and from the tissues of the wild animal, designated as "primary samples", were genotyped by PCR-restriction fragment length polymorphism (PCR/RFLP), using 12 genetic markers (SAG1, SAG2, alt.SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L258, PK1, CS3 and Apico). A total of 17 genotypes were identified, with 13 identified for the first time and four already reported in published literature. Results herein obtained corroborate previous studies in Brazil, confirming high diversity and revealing unique genotypes in this region. Given most of genotypes here identified are different from previous studies in domestic animals, future studies on T. gondii from wildlife is of interest to understand population genetics and structure of this parasite.

  13. Revealing conceptual understanding of international business

    NARCIS (Netherlands)

    Sue Ashley; Dr. Harmen Schaap; Prof.Dr. Elly de Bruijn

    2017-01-01

    This study aims to identify an adequate approach for revealing conceptual understanding in higher professional education. Revealing students’ conceptual understanding is an important step towards developing effective curricula, assessment and aligned teaching strategies to enhance conceptual

  14. Bats from Fazenda Intervales, Southeastern Brazil: species account and comparison between different sampling methods

    Directory of Open Access Journals (Sweden)

    Christine V. Portfors

    2000-06-01

    Full Text Available Assessing the composition of an area's bat fauna is typically accomplished by using captures or by monitoring echolocation calls with bat detectors. The two methods may not provide the same data regarding species composition. Mist nets and harp traps may be biased towards sampling low flying species, and bat detectors biased towards detecting high intensity echolocators. A comparison of the bat fauna of Fazenda Intervales, southeastern Brazil, as revealed by mist nets and harp trap captures, checking roosts and by monitoring echolocation calls of flying bats illustrates this point. A total of 17 species of bats was sampled. Fourteen bat species were captured and the echolocation calls of 12 species were recorded, three of them not revealed by mist nets or harp traps. The different sampling methods provided different pictures of the bat fauna. Phyllostomid bats dominated the catches in mist nets, but in the field their echolocation calls were never detected. No single sampling approach provided a complete assessment of the bat fauna in the study area. In general, bats producing low intensity echolocation calls, such as phyllostomids, are more easily assessed by netting, and bats producing high intensity echolocation calls are better surveyed by bat detectors. The results demonstrate that a combined and varied approach to sampling is required for a complete assessment of the bat fauna of an area.

  15. Infant behaviour questionnaire - revised version: a psychometric study in a Portuguese sample.

    Science.gov (United States)

    Costa, Raquel; Figueiredo, Bárbara

    2018-04-01

    Although the original characteristics of temperament tend to remain constant over the course of development, environmental circumstances may influence infants' reactions and behaviour. Parents' reports of infant temperament are rich informants of infant behaviours in different contexts. This study aimed to examine the psychometric properties of the Portuguese version of the Infant Behaviour Questionnaire - Revised (IBQ-R) and test the adequacy of the original and other previously published structures to the Portuguese data. 330 mothers and 81 fathers of children aged between 3 and 12 months completed the Portuguese version of the IBQ-R. The confirmatory factorial analysis revealed a non-adequate model fit of the IBQ-R original structure to the Portuguese data; nonetheless, it did reveal an adequate model fit of a previous published IBQ-R structure. This structure, although only slightly different from the original one, seems to be more suitable for the Portuguese data. This study provides data that indicates that the IBQ-R is a reliable questionnaire to evaluate infant temperament in the Portuguese culture.

  16. Study of Organochlorinated Pesticide Residues and Polychlorinated Biphenyls in Soil Samples

    Directory of Open Access Journals (Sweden)

    MSc. Vlora Gashi

    2013-12-01

    Full Text Available This paper presents and discusses the data obtained for organochlorinated pesticides and their residues in the soil samples of agricultural areas. Soil contamination is one of most important factors influencing the quality of agricultural products. Usage of heavy farm equipment, the land drainage, an exces­sive application of agrochemicals, emissions originating from mining, metallurgical, and chemical and coal power plants and transport, all generate a number of undesired substances (nitric and sulphur oxides, PAHs, heavy metals, pesticides, which after deposition in soil may influence crop quality. Thus, input of these contaminants into the environment should be carefully monitored. Levels of organochlorinated pesticides contamination were evaluated in agriculture areas that are in use. 10 soil samples were taken in agricultural areas  Plane of  Dugagjini , Kosovo. Representa­tive soil samples were collected from 0-30 cm top layer of the soil. In the analytical method we combined ultrasonic bath extraction and a Florisil column for samples clean-up. The analysis of the organochlorinated pesticides in soil samples was performed by gas chromatography technique using electron capture detector (GC/ECD. Optima-5 (low/mid polarity, 5% phenyl methyl siloxane 60 m x 0.33 mm x 0.25μm film capillary column was used for isolation and determination of organochlorinated pesticides. Low concentrations of organochlorinated pesticide and their metabolites were found in the studied samples. The presence of organochlorinated pesticides and their residues is probably resulting of their previous uses for agricultural purposes.

  17. Pierre Gy's sampling theory and sampling practice heterogeneity, sampling correctness, and statistical process control

    CERN Document Server

    Pitard, Francis F

    1993-01-01

    Pierre Gy's Sampling Theory and Sampling Practice, Second Edition is a concise, step-by-step guide for process variability management and methods. Updated and expanded, this new edition provides a comprehensive study of heterogeneity, covering the basic principles of sampling theory and its various applications. It presents many practical examples to allow readers to select appropriate sampling protocols and assess the validity of sampling protocols from others. The variability of dynamic process streams using variography is discussed to help bridge sampling theory with statistical process control. Many descriptions of good sampling devices, as well as descriptions of poor ones, are featured to educate readers on what to look for when purchasing sampling systems. The book uses its accessible, tutorial style to focus on professional selection and use of methods. The book will be a valuable guide for mineral processing engineers; metallurgists; geologists; miners; chemists; environmental scientists; and practit...

  18. Field-based random sampling without a sampling frame: control selection for a case-control study in rural Africa.

    Science.gov (United States)

    Crampin, A C; Mwinuka, V; Malema, S S; Glynn, J R; Fine, P E

    2001-01-01

    Selection bias, particularly of controls, is common in case-control studies and may materially affect the results. Methods of control selection should be tailored both for the risk factors and disease under investigation and for the population being studied. We present here a control selection method devised for a case-control study of tuberculosis in rural Africa (Karonga, northern Malawi) that selects an age/sex frequency-matched random sample of the population, with a geographical distribution in proportion to the population density. We also present an audit of the selection process, and discuss the potential of this method in other settings.

  19. Microscopic and UPLC-UV-MS analyses of authentic and commercial yohimbe (Pausinystalia johimbe) bark samples.

    Science.gov (United States)

    Raman, Vijayasankar; Avula, Bharathi; Galal, Ahmed M; Wang, Yan-Hong; Khan, Ikhlas A

    2013-01-01

    Yohimbine is the major alkaloid found in the stem bark of yohimbe, Pausinystalia johimbe (Rubiaceae), an evergreen tree native to Africa. The objectives of the current study were to provide a detailed anatomy of yohimbe bark, as well as to determine the quantity of yohimbine in the raw yohimbe products sold online. Twelve commercial raw materials of yohimbe were analyzed by microscopic and ultra performance liquid chromatography-UV-MS methods. The study revealed that three samples were probably adulterated and four other samples contained various levels of impurities. Yohimbine was not detected in one sample, whereas its presence in other samples was found to be in the range 0.1-0.91%. The present work also provides a detailed anatomy of the stem bark of yohimbe, with light and scanning electron microscopy images, for proper identification and authentication.

  20. Study on sampling of continuous linear system based on generalized Fourier transform

    Science.gov (United States)

    Li, Huiguang

    2003-09-01

    In the research of signal and system, the signal's spectrum and the system's frequency characteristic can be discussed through Fourier Transform (FT) and Laplace Transform (LT). However, some singular signals such as impulse function and signum signal don't satisfy Riemann integration and Lebesgue integration. They are called generalized functions in Maths. This paper will introduce a new definition -- Generalized Fourier Transform (GFT) and will discuss generalized function, Fourier Transform and Laplace Transform under a unified frame. When the continuous linear system is sampled, this paper will propose a new method to judge whether the spectrum will overlap after generalized Fourier transform (GFT). Causal and non-causal systems are studied, and sampling method to maintain system's dynamic performance is presented. The results can be used on ordinary sampling and non-Nyquist sampling. The results also have practical meaning on research of "discretization of continuous linear system" and "non-Nyquist sampling of signal and system." Particularly, condition for ensuring controllability and observability of MIMO continuous systems in references 13 and 14 is just an applicable example of this paper.

  1. Molecular detection of eukaryotes in a single human stool sample from Senegal.

    Directory of Open Access Journals (Sweden)

    Ibrahim Hamad

    Full Text Available BACKGROUND: Microbial eukaryotes represent an important component of the human gut microbiome, with different beneficial or harmful roles; some species are commensal or mutualistic, whereas others are opportunistic or parasitic. The diversity of eukaryotes inhabiting humans remains relatively unexplored because of either the low abundance of these organisms in human gut or because they have received limited attention from a whole-community perspective. METHODOLOGY/PRINCIPAL FINDING: In this study, a single fecal sample from a healthy African male was studied using both culture-dependent methods and extended molecular methods targeting the 18S rRNA and ITS sequences. Our results revealed that very few fungi, including Candida spp., Galactomyces spp., and Trichosporon asahii, could be isolated using culture-based methods. In contrast, a relatively a high number of eukaryotic species could be identified in this fecal sample when culture-independent methods based on various primer sets were used. A total of 27 species from one sample were found among the 977 analyzed clones. The clone libraries were dominated by fungi (716 clones/977, 73.3%, corresponding to 16 different species. In addition, 187 sequences out of 977 (19.2% corresponded to 9 different species of plants; 59 sequences (6% belonged to other micro-eukaryotes in the gut, including Entamoeba hartmanni and Blastocystis sp; and only 15 clones/977 (1.5% were related to human 18S rRNA sequences. CONCLUSION: Our results revealed a complex eukaryotic community in the volunteer's gut, with fungi being the most abundant species in the stool sample. Larger investigations are needed to assess the generality of these results and to understand their roles in human health and disease.

  2. Numerical study of the lateral resolution in electrostatic force microscopy for dielectric samples

    International Nuclear Information System (INIS)

    Riedel, C; AlegrIa, A; Colmenero, J; Schwartz, G A; Saenz, J J

    2011-01-01

    We present a study of the lateral resolution in electrostatic force microscopy for dielectric samples in both force and gradient modes. Whereas previous studies have reported expressions for metallic surfaces having potential heterogeneities (Kelvin probe force microscopy), in this work we take into account the presence of a dielectric medium. We introduce a definition of the lateral resolution based on the force due to a test particle being either a point charge or a polarizable particle on the dielectric surface. The behaviour has been studied over a wide range of typical experimental parameters: tip-sample distance (1-20) nm, sample thickness (0-5) μm and dielectric constant (1-20), using the numerical simulation of the equivalent charge method. For potential heterogeneities on metallic surfaces expressions are in agreement with the bibliography. The lateral resolution of samples having a dielectric constant of more than 10 tends to metallic behaviour. We found a characteristic thickness of 100 nm, above which the lateral resolution measured on the dielectric surface is close to that of an infinite medium. As previously reported, the lateral resolution is better in the gradient mode than in the force mode. Finally, we showed that for the same experimental conditions, the lateral resolution is better for a polarizable particle than for a charge, i.e. dielectric heterogeneities should always look 'sharper' (better resolved) than inhomogeneous charge distributions. This fact should be taken into account when interpreting images of heterogeneous samples.

  3. Numerical study of the lateral resolution in electrostatic force microscopy for dielectric samples

    Energy Technology Data Exchange (ETDEWEB)

    Riedel, C; AlegrIa, A; Colmenero, J [Departamento de Fisica de Materiales UPV/EHU, Facultad de Quimica, Apartado 1072, 20080 San Sebastian (Spain); Schwartz, G A [Centro de Fisica de Materiales CSIC-UPV/EHU, Paseo Manuel de Lardizabal 5, 20018 San Sebastian (Spain); Saenz, J J, E-mail: riedel@ies.univ-montp2.fr [Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastian (Spain)

    2011-07-15

    We present a study of the lateral resolution in electrostatic force microscopy for dielectric samples in both force and gradient modes. Whereas previous studies have reported expressions for metallic surfaces having potential heterogeneities (Kelvin probe force microscopy), in this work we take into account the presence of a dielectric medium. We introduce a definition of the lateral resolution based on the force due to a test particle being either a point charge or a polarizable particle on the dielectric surface. The behaviour has been studied over a wide range of typical experimental parameters: tip-sample distance (1-20) nm, sample thickness (0-5) {mu}m and dielectric constant (1-20), using the numerical simulation of the equivalent charge method. For potential heterogeneities on metallic surfaces expressions are in agreement with the bibliography. The lateral resolution of samples having a dielectric constant of more than 10 tends to metallic behaviour. We found a characteristic thickness of 100 nm, above which the lateral resolution measured on the dielectric surface is close to that of an infinite medium. As previously reported, the lateral resolution is better in the gradient mode than in the force mode. Finally, we showed that for the same experimental conditions, the lateral resolution is better for a polarizable particle than for a charge, i.e. dielectric heterogeneities should always look 'sharper' (better resolved) than inhomogeneous charge distributions. This fact should be taken into account when interpreting images of heterogeneous samples.

  4. Evaluation of Skin Surface as an Alternative Source of Reference DNA Samples: A Pilot Study.

    Science.gov (United States)

    Albujja, Mohammed H; Bin Dukhyil, Abdul Aziz; Chaudhary, Abdul Rauf; Kassab, Ahmed Ch; Refaat, Ahmed M; Babu, Saranya Ramesh; Okla, Mohammad K; Kumar, Sachil

    2018-01-01

    An acceptable area for collecting DNA reference sample is a part of the forensic DNA analysis development. The aim of this study was to evaluate skin surface cells (SSC) as an alternate source of reference DNA sample. From each volunteer (n = 10), six samples from skin surface areas (forearm and fingertips) and two traditional samples (blood and buccal cells) were collected. Genomic DNA was extracted and quantified then genotyped using standard techniques. The highest DNA concentration of SSC samples was collected using the tape/forearm method of collection (2.1 ng/μL). Cotton swabs moistened with ethanol yielded higher quantities of DNA than swabs moistened with salicylic acid, and it gave the highest percentage of full STR profiles (97%). This study supports the use of SSC as a noninvasive sampling technique and as a extremely useful source of DNA reference samples among certain cultures where the use of buccal swabs can be considered socially unacceptable. © 2017 American Academy of Forensic Sciences.

  5. The study of penetration of energetic ions in botanic samples with transmission measurements

    International Nuclear Information System (INIS)

    Wang, Y.G.; Chen, Q.Z.; Xue, J.M.; Du, G.H.; Qin, H.L; Zhang, W.M.; Yan, S.; Zhao, W.J.

    2006-01-01

    Botanic samples (onion endocuticles, kidney bean slices) were exposed to energetic ions. By recording transmission spectra, we studied the energy loss in such samples. Individual protrusion-like damage produced in highly oriented pyrolytic graphite (HOPG) substrate allowed us to analyze the mass density of the samples by scanning tunneling microscope (STM). The experimental results showed that the botanic sample is inhomogeneous in mass density, some incident ions lose only a small part of their energy after being stopped by a layer of botanic sample. Additionally, about 10 -7 of the incident ions with energy of tens of keV can penetrate through the botanic slice with a thickness of 50 μm. The dynamic change of the transmission spectrum of MeV heavy ions through a layer of botanic slice showed that the penetration ability of the incident ions increases with increasing ion fluence. These experimental results indicate that the inhomogeneousity of mass density of botanic samples and irradiation damage are the main reasons of the ultra-depth penetration of low-energy ions in such kind of botanic samples

  6. A sampling study on rock properties affecting drilling rate index (DRI)

    Science.gov (United States)

    Yenice, Hayati; Özdoğan, Mehmet V.; Özfırat, M. Kemal

    2018-05-01

    Drilling rate index (DRI) developed in Norway is a very useful index in determining the drillability of rocks and even in performance prediction of hard rock TBMs and it requires special laboratory test equipment. Drillability is one of the most important subjects in rock excavation. However, determining drillability index from physical and mechanical properties of rocks is very important for practicing engineers such as underground excavation, drilling operations in open pit mining, underground mining and natural stone production. That is why many researchers have studied concerned with drillability to find the correlations between drilling rate index (DRI) and penetration rate, influence of geological properties on drillability prediction in tunneling, correlations between rock properties and drillability. In this study, the relationships between drilling rate index (DRI) and some physico-mechanical properties (Density, Shore hardness, uniaxial compressive strength (UCS, σc), Indirect tensile strength (ITS, σt)) of three different rock groups including magmatic, sedimentary and metamorphic were evaluated using both simple and multiple regression analysis. This study reveals the effects of rock properties on DRI according to different types of rocks. In simple regression, quite high correlations were found between DRI and uniaxial compressive strength (UCS) and also between DRI and indirect tensile strength (ITS) values. Multiple regression analyses revealed even higher correlations when compared to simple regression. Especially, UCS, ITS, Shore hardness (SH) and the interactions between them were found to be very effective on DRI values.

  7. Do women's voices provide cues of the likelihood of ovulation? The importance of sampling regime.

    Directory of Open Access Journals (Sweden)

    Julia Fischer

    Full Text Available The human voice provides a rich source of information about individual attributes such as body size, developmental stability and emotional state. Moreover, there is evidence that female voice characteristics change across the menstrual cycle. A previous study reported that women speak with higher fundamental frequency (F0 in the high-fertility compared to the low-fertility phase. To gain further insights into the mechanisms underlying this variation in perceived attractiveness and the relationship between vocal quality and the timing of ovulation, we combined hormone measurements and acoustic analyses, to characterize voice changes on a day-to-day basis throughout the menstrual cycle. Voice characteristics were measured from free speech as well as sustained vowels. In addition, we asked men to rate vocal attractiveness from selected samples. The free speech samples revealed marginally significant variation in F0 with an increase prior to and a distinct drop during ovulation. Overall variation throughout the cycle, however, precluded unequivocal identification of the period with the highest conception risk. The analysis of vowel samples revealed a significant increase in degree of unvoiceness and noise-to-harmonic ratio during menstruation, possibly related to an increase in tissue water content. Neither estrogen nor progestogen levels predicted the observed changes in acoustic characteristics. The perceptual experiments revealed a preference by males for voice samples recorded during the pre-ovulatory period compared to other periods in the cycle. While overall we confirm earlier findings in that women speak with a higher and more variable fundamental frequency just prior to ovulation, the present study highlights the importance of taking the full range of variation into account before drawing conclusions about the value of these cues for the detection of ovulation.

  8. Exhaustive sampling of docking poses reveals binding hypotheses for propafenone type inhibitors of P-glycoprotein.

    Directory of Open Access Journals (Sweden)

    Freya Klepsch

    2011-05-01

    Full Text Available Overexpression of the xenotoxin transporter P-glycoprotein (P-gp represents one major reason for the development of multidrug resistance (MDR, leading to the failure of antibiotic and cancer therapies. Inhibitors of P-gp have thus been advocated as promising candidates for overcoming the problem of MDR. However, due to lack of a high-resolution structure the concrete mode of interaction of both substrates and inhibitors is still not known. Therefore, structure-based design studies have to rely on protein homology models. In order to identify binding hypotheses for propafenone-type P-gp inhibitors, five different propafenone derivatives with known structure-activity relationship (SAR pattern were docked into homology models of the apo and the nucleotide-bound conformation of the transporter. To circumvent the uncertainty of scoring functions, we exhaustively sampled the pose space and analyzed the poses by combining information retrieved from SAR studies with common scaffold clustering. The results suggest propafenone binding at the transmembrane helices 5, 6, 7 and 8 in both models, with the amino acid residue Y307 playing a crucial role. The identified binding site in the non-energized state is overlapping with, but not identical to, known binding areas of cyclic P-gp inhibitors and verapamil. These findings support the idea of several small binding sites forming one large binding cavity. Furthermore, the binding hypotheses for both catalytic states were analyzed and showed only small differences in their protein-ligand interaction fingerprints, which indicates only small movements of the ligand during the catalytic cycle.

  9. Comparison of Different Sample Preparation Protocols Reveals Lysis Buffer-Specific Extraction Biases in Gram-Negative Bacteria and Human Cells.

    Science.gov (United States)

    Glatter, Timo; Ahrné, Erik; Schmidt, Alexander

    2015-11-06

    We evaluated different in-solution and FASP-based sample preparation strategies for absolute protein quantification. Label-free quantification (LFQ) was employed to compare different sample preparation strategies in the bacterium Pseudomonas aeruginosa and human embryonic kidney cells (HEK), and organismal-specific differences in general performance and enrichment of specific protein classes were noted. The original FASP protocol globally enriched for most proteins in the bacterial sample, whereas the sodium deoxycholate in-solution strategy was more efficient with HEK cells. Although detergents were found to be highly suited for global proteome analysis, higher intensities were obtained for high-abundant nucleic acid-associated protein complexes, like the ribosome and histone proteins, using guanidine hydrochloride. Importantly, we show for the first time that the observable total proteome mass of a sample strongly depends on the sample preparation protocol, with some protocols resulting in a significant underestimation of protein mass due to incomplete protein extraction of biased protein groups. Furthermore, we demonstrate that some of the observed abundance biases can be overcome by incorporating a nuclease treatment step or, alternatively, a correction factor for complementary sample preparation approaches.

  10. Feasibility studies on large sample neutron activation analysis using a low power research reactor

    International Nuclear Information System (INIS)

    Gyampo, O.

    2008-06-01

    Instrumental neutron activation analysis (INAA) using Ghana Research Reactor-1 (GHARR-1) can be directly applied to samples with masses in grams. Samples weights were in the range of 0.5g to 5g. Therefore, the representativity of the sample is improved as well as sensitivity. Irradiation of samples was done using a low power research reactor. The correction for the neutron self-shielding within the sample is determined from measurement of the neutron flux depression just outside the sample. Correction for gamma ray self-attenuation in the sample was performed via linear attenuation coefficients derived from transmission measurements. Quantitative and qualitative analysis of data were done using gamma ray spectrometry (HPGe detector). The results of this study on the possibilities of large sample NAA using a miniature neutron source reactor (MNSR) show clearly that the Ghana Research Reactor-1 (GHARR-1) at the National Nuclear Research Institute (NNRI) can be used for sample analyses up to 5 grams (5g) using the pneumatic transfer systems.

  11. Recruiting a representative sample in adherence research-The MALT multisite prospective cohort study experience.

    Science.gov (United States)

    Shemesh, Eyal; Mitchell, Jeffrey; Neighbors, Katie; Feist, Susan; Hawkins, Andre; Brown, Amanda; Wanrong, Yin; Anand, Ravinder; Stuber, Margaret L; Annunziato, Rachel A

    2017-12-01

    Medication adherence is an important determinant of transplant outcomes. Attempts to investigate adherence are frequently undermined by selection bias: It is very hard to recruit and retain non-adherent patients in research efforts. This manuscript presents recruitment strategies and results from the MALT (Medication Adherence in children who had a Liver Transplant) multisite prospective cohort study. MALT sites recruited 400 pediatric liver transplant patients who agreed to be followed for 2 years. The primary purpose was to determine whether a marker of adherence, the Medication Level Variability Index (MLVI), predicts rejection outcomes. The present manuscript describes methods used in MALT to ensure that a representative sample was recruited, and presents detailed recruitment results. MALT sites were able to recruit a nationally representative sample, as determined by a comparison between the MALT cohort and a national sample of transplant recipients. Strategies that helped ensure that the sample was representative included monitoring of the outcome measure in comparison with a national sample, drastically limiting patient burden, and specific recruitment methods. We discuss the importance of a representative sample in adherence research and recommend that future efforts to study adherence pay special attention to sample characteristics. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. [Formal sample size calculation and its limited validity in animal studies of medical basic research].

    Science.gov (United States)

    Mayer, B; Muche, R

    2013-01-01

    Animal studies are highly relevant for basic medical research, although their usage is discussed controversially in public. Thus, an optimal sample size for these projects should be aimed at from a biometrical point of view. Statistical sample size calculation is usually the appropriate methodology in planning medical research projects. However, required information is often not valid or only available during the course of an animal experiment. This article critically discusses the validity of formal sample size calculation for animal studies. Within the discussion, some requirements are formulated to fundamentally regulate the process of sample size determination for animal experiments.

  13. Oppositional Behavior and Anxiety in Boys and Girls: A Cross-Sectional Study in Two Community Samples

    Science.gov (United States)

    Mireault, Gina; Rooney, Siri; Kouwenhoven, Kristen; Hannan, Carolyn

    2008-01-01

    Studies have repeatedly shown that oppositional behavior is linked to anxiety in clinical samples of children. This study explored whether these variables were similarly related in nonclinical samples of elementary and middle school students (N = 302). Despite greater self-reported oppositional behavior among boys in these samples, anxiety…

  14. Mössbauer Spectroscopy of Samples from the 2010 Eyjafjallajökull Summit Eruption

    DEFF Research Database (Denmark)

    Gunnlaugsson, Haraldur Pall; Höskuldsson, Á.; Steinthorsson, S.

    2012-01-01

    The 2010 Eyjafjallajökull summit eruption (Iceland) produced large amounts of fine ash, disturbing air traffic across the North-Atlantic and within Europe. Mössbauer spectroscopy of ash-samples and a lava-bomb has been performed to study the material properties and to gain insight into why...... the volcano produced so vast amounts of fine grained material. Time series of ash samples reveal a changing ferric to ferrous ratio and level of crystallization which can be related to the different phases of the eruption. The lava bomb has a much lower ferric to ferrous ratio, implying that this relatively...

  15. Isotopic studies of rare gases in terrestrial samples and natural nucleosynthesis

    International Nuclear Information System (INIS)

    1990-07-01

    This project is concerned with research in rare gas mass spectrometry. We read the natural record that isotopes of the rare gases provide. We study fluids using a system (RARGA) that is sometimes deployed in the field. In 1990 there was a strong effort to reduce the backlog of RARGA samples on hand, so that it was a year of intensive data gathering. Samples from five different areas in the western United States and samples from Guatemala and Australia were analyzed. In a collaborative study we also began analyzing noble gases from rocks associated with the fluids. An important objective, continuing in 1991, is to understand better the reasons for somewhat elevated 3 He/ 4 He ratios in regions where there is no contemporary volcanism which could produce the effect by addition of mantle helium. Our helium data have given us and our collaborators some insights, which are to be followed up, into gold mineralization in geothermal regions. Our DOE work in calibrating a sensitive laser microprobe mass spectrometer for noble gases in fluid inclusions continues. Having completed a series of papers on noble gases in diamonds, we next will attempt to make precise isotopic measurements on xenon from mantle sources, in search of evidence for terrestrially elusive 244 Pu decay

  16. Isotopic studies of rare gases in terrestrial samples and natural nucleosynthesis

    International Nuclear Information System (INIS)

    Reynolds, J.H.

    1991-01-01

    This project is concerned with research in rare gas mass spectrometry. We read the natural record that isotopes of the rate gases provide. We study fluids using a system (RARGA) that is sometimes deployed in the field. In 1990 there was a strong effort to reduce the backlog of RARGA samples on hand, so that it was a year of intensive data gathering. Samples from five different areas in the Western United States and samples from Guatemala and Australia were analyzed. In a collaborative study we also began analyzing noble gases from rocks associated with the fluids. An important objective, continuing in 1991, is to understand better the reasons for somewhat elevated 3 He/ 4 He ratios in regions where there is no contemporary volcanism which could produce the effect by addition of mantle helium. Our helium data have given us and our collaborators some insights, which are to be followed up, into gold mineralization in geothermal regions. Our DOE work in calibrating a sensitive laser microprobe mass spectrometer for noble gases in fluid inclusions continues. Having completed a series of papers on noble gases in diamonds, we next will attempt to make precise isotopic measurements on xenon from mantle sources in search of evidence for terrestrially elusive 244 Pu decay. 41 refs., 3 figs

  17. Industrial variographic analysis for continuous sampling system validation

    DEFF Research Database (Denmark)

    Engström, Karin; Esbensen, Kim Harry

    2017-01-01

    Karin Engström, LKAB mining, Kiruna, Sweden, continues to present illuminative cases from process industry. Here she reveals more from her ongoing PhD project showing application of variographic characterisation for on-line continuous control of process sampling systems, including the one...

  18. Tritium inventory differences: I. Sampling and U-getter pump holdup

    International Nuclear Information System (INIS)

    Ellefson, R.E.; Gill, J.T.

    1986-01-01

    Inventory differences (ID) in tritium material balance accounts (MBA) can occur with unmeasured transfers from the process or unmeasured holdup in the system. Small but cumulatively significant quantities of tritium can leave the MBA by normal capillary sampling of process gas operation. A predictor model for estimating the quantity of tritium leaving the MBA by sampling has been developed and implemented. The model calculates the gas transferred per sample; using the tritium concentration in the process and the number of samples, a quantity of tritium transferred is predicted. Verification of the model is made by PVT measurement of process transfer from multiple samplings. Comparison of predicted sample transfers with IDs from several MBA's reveals that sampling typically represents 50% of unmeasured transfers for regularly sampled processes

  19. A comprehensive modeling and vibration analysis of AFM microcantilevers subjected to nonlinear tip-sample interaction forces

    International Nuclear Information System (INIS)

    Eslami, Sohrab; Jalili, Nader

    2012-01-01

    Precise and accurate representation of an Atomic Force Microscopy (AFM) system is essential in studying the effects of boundary interaction forces present between the probe's tip and the sample. In this paper, a comprehensive analytical model for the AFM system utilizing a distributed-parameters based approach is proposed. More specifically, we consider two important attributes of these systems; namely the rotary inertia and shear deformation when compared with the Euler–Bernoulli beam theory. Moreover, a comprehensive nonlinear interaction force is assumed between probe's and sample in order to reveal the response of the system more realistically. This nanoscale interaction force is based on a general form consisting of both attractive and repulsive components as well as a function of the tip-sample distance and the microcantilever's base and sample oscillations. Mechanical properties of the sample could interact with the nanomechanical coupling field between the probe' tip and sample and be implemented in studying the composition information of the sample and the ultra-small features inside it. Therefore, by modulating the dynamics of the AFM system such as the driving amplitude of the microcantilever the procedure for the subsurface imaging is described. The presented approach here could be implemented for designing the AFM probes by examining the tip-sample interaction forces dominant by the van der Waals forces. Several numerical case studies are presented and the force–distance diagram reveals that the proposed nonlinear nanomechanical force along with the distributed-parameters model for the microcantilever is able to fulfill the mechanics of the Lennard–Jones potential. -- Highlights: ► We present a comprehensive distributed-parameters model for AFM microcantilever. ► Assuming a nonlinear and implicit interaction force between tip and sample. ► Timoshenko beam is compared with the Euler–Bernoulli having the same force model. ► Frequency

  20. Replication of a Modified Factor Structure for the Eating Disorder Examination-Questionnaire: Extension to Clinical Eating Disorder and Non-clinical Samples in Portugal.

    Science.gov (United States)

    Machado, Paulo P P; Grilo, Carlos M; Crosby, Ross D

    2018-01-01

    Psychometric investigations of the Eating Disorder Examination-Questionnaire (EDE-Q) have generally not supported the original scale structure. The present study tested an alternative brief factor structure in two large Portuguese samples: (1) a non-clinical sample of N = 4117 female students and (2) a treatment-seeking sample of N = 609 patients diagnosed with eating disorders. Confirmatory factor analysis revealed a poor fit for the original EDE-Q structure in both the non-clinical and the clinical samples but revealed a good fit for the alternative 7-item 3-factor structure (dietary restraint, shape/weight overvaluation and body dissatisfaction). Factor loadings were invariant across samples and across the different specific eating disorder diagnoses in the clinical sample. These confirmatory factor analysis findings, which replicate findings from studies with diverse predominately overweight/obese samples, supported a modified 7-item, 3-factor structure for the EDE-Q. The reliable findings across different non-clinical and clinical eating disorder groups provide confidence regarding the potential utility of this brief version. Copyright © 2017 John Wiley & Sons, Ltd and Eating Disorders Association. Copyright © 2017 John Wiley & Sons, Ltd and Eating Disorders Association.

  1. Phylogeographic analyses of the pampas cat (Leopardus colocola; Carnivora, Felidae) reveal a complex demographic history

    Science.gov (United States)

    da Silva Santos, Anelisie; Trigo, Tatiane Campos; de Oliveira, Tadeu Gomes; Silveira, Leandro

    2018-01-01

    Abstract The pampas cat is a small felid that occurs in open habitats throughout much of South America. Previous studies have revealed intriguing patterns of morphological differentiation and genetic structure among its populations, as well as molecular evidence for hybridization with the closely related L. tigrinus. Here we report phylogeographic analyses encompassing most of its distribution (focusing particularly on Brazilian specimens, which had been poorly sampled in previous studies), using a novel dataset comprising 2,143 bp of the mitogenome, along with previously reported mtDNA sequences. Our data revealed strong population strutucture and supported a west-to-east colonization process in this species’ history. We detected two population expansion events, one older (ca. 200 thousand years ago [kya]) in western South America and another more recent (ca. 60-50 kya) in eastern areas, coinciding with the expansion of savanna environments in Brazil. Analyses including L. tigrinus individuals bearing introgressed mtDNA from L. colocola showed a complete lack of shared haplotypes between species, indicating that their hybridization was ancient. Finally, we observed a close relationship between Brazilian/Uruguayan L. colocola haplotypes and those sampled in L. tigrinus, indicating that their hybridization was likely related to the demographic expansion of L. colocola into eastern South America. PMID:29668017

  2. Revealing Conceptual Understanding of International Business

    Science.gov (United States)

    Ashley, Sue; Schaap, Harmen; de Bruijn, Elly

    2017-01-01

    This study aims to identify an adequate approach for revealing conceptual understanding in higher professional education. Revealing students' conceptual understanding is an important step towards developing effective curricula, assessment and aligned teaching strategies to enhance conceptual understanding in higher education. Essays and concept…

  3. Stable isotope analysis of precipitation samples obtained via crowdsourcing reveals the spatiotemporal evolution of Superstorm Sandy.

    Directory of Open Access Journals (Sweden)

    Stephen P Good

    Full Text Available Extra-tropical cyclones, such as 2012 Superstorm Sandy, pose a significant climatic threat to the northeastern United Sates, yet prediction of hydrologic and thermodynamic processes within such systems is complicated by their interaction with mid-latitude water patterns as they move poleward. Fortunately, the evolution of these systems is also recorded in the stable isotope ratios of storm-associated precipitation and water vapor, and isotopic analysis provides constraints on difficult-to-observe cyclone dynamics. During Superstorm Sandy, a unique crowdsourced approach enabled 685 precipitation samples to be obtained for oxygen and hydrogen isotopic analysis, constituting the largest isotopic sampling of a synoptic-scale system to date. Isotopically, these waters span an enormous range of values (> 21‰ for δ(18O, > 160‰ for δ(2H and exhibit strong spatiotemporal structure. Low isotope ratios occurred predominantly in the west and south quadrants of the storm, indicating robust isotopic distillation that tracked the intensity of the storm's warm core. Elevated values of deuterium-excess (> 25‰ were found primarily in the New England region after Sandy made landfall. Isotope mass balance calculations and Lagrangian back-trajectory analysis suggest that these samples reflect the moistening of dry continental air entrained from a mid-latitude trough. These results demonstrate the power of rapid-response isotope monitoring to elucidate the structure and dynamics of water cycling within synoptic-scale systems and improve our understanding of storm evolution, hydroclimatological impacts, and paleo-storm proxies.

  4. Stable isotope analysis of precipitation samples obtained via crowdsourcing reveals the spatiotemporal evolution of Superstorm Sandy.

    Science.gov (United States)

    Good, Stephen P; Mallia, Derek V; Lin, John C; Bowen, Gabriel J

    2014-01-01

    Extra-tropical cyclones, such as 2012 Superstorm Sandy, pose a significant climatic threat to the northeastern United Sates, yet prediction of hydrologic and thermodynamic processes within such systems is complicated by their interaction with mid-latitude water patterns as they move poleward. Fortunately, the evolution of these systems is also recorded in the stable isotope ratios of storm-associated precipitation and water vapor, and isotopic analysis provides constraints on difficult-to-observe cyclone dynamics. During Superstorm Sandy, a unique crowdsourced approach enabled 685 precipitation samples to be obtained for oxygen and hydrogen isotopic analysis, constituting the largest isotopic sampling of a synoptic-scale system to date. Isotopically, these waters span an enormous range of values (> 21‰ for δ(18)O, > 160‰ for δ(2)H) and exhibit strong spatiotemporal structure. Low isotope ratios occurred predominantly in the west and south quadrants of the storm, indicating robust isotopic distillation that tracked the intensity of the storm's warm core. Elevated values of deuterium-excess (> 25‰) were found primarily in the New England region after Sandy made landfall. Isotope mass balance calculations and Lagrangian back-trajectory analysis suggest that these samples reflect the moistening of dry continental air entrained from a mid-latitude trough. These results demonstrate the power of rapid-response isotope monitoring to elucidate the structure and dynamics of water cycling within synoptic-scale systems and improve our understanding of storm evolution, hydroclimatological impacts, and paleo-storm proxies.

  5. Inter-laboratory exercise on steroid estrogens in aqueous samples

    International Nuclear Information System (INIS)

    Heath, E.; Kosjek, T.; Andersen, H.R.; Holten Luetzhoft, H.-C.; Adolfson Erici, M.; Coquery, M.; Duering, R.-A.; Gans, O.; Guignard, C.; Karlsson, P.; Manciot, F.; Moldovan, Z.; Patureau, D.; Cruceru, L.; Sacher, F.; Ledin, A.

    2010-01-01

    An inter-laboratory comparison exercise was organized among European laboratories, under the aegis of EU COST Action 636: 'Xenobiotics in Urban Water Cycle'. The objective was to evaluate the performance of testing laboratories determining 'Endocrine Disrupting Compounds' (EDC) in various aqueous matrices. As the main task three steroid estrogens: 17α-ethinylestradiol, 17β-estradiol and estrone were determined in four spiked aqueous matrices: tap water, river water and wastewater treatment plant influent and effluent using GC-MS and LC-MS/MS. Results were compared and discussed according to the analytical techniques applied, the accuracy and reproducibility of the analytical methods and the nature of the sample matrices. Overall, the results obtained in this inter-laboratory exercise reveal a high level of competence among the participating laboratories for the detection of steroid estrogens in water samples indicating that GC-MS as well as LC-MS/MS can equally be employed for the analysis of natural and synthetic hormones. - Herein are presented the results of the first international inter-laboratory study on determination of selected steroid hormones in environmental aqueous samples.

  6. Charged-particle track analysis, thermoluminescence and microcratering studies of lunar samples

    International Nuclear Information System (INIS)

    Durrani, S.A.

    1977-01-01

    Studies of lunar samples (from both Apollo and Luna missions) have been carried out, using track analysis and thermoluminescence (t.l.) techniques, with a view to shedding light on the radiation and temperature histories of the Moon. In addition, microcraters in lunar glasses have been studied in order to elucidate the cosmic-dust impact history of the lunar regolith. In tracks studies, the topics discussed include the stabilizing effect of the thermal annealing of fossil tracks due to the lunar temperature cycle; the 'radiation annealing' of fresh heavy-ion tracks by large doses of protons (to simulate the effect of lunar radiation-damage on track registration); and correction factors for the anisotropic etching of crystals which are required in reconstructing the exposure history of lunar grains. An abundance ratio of ca. (1.1 + 0.3) x 10 -3 has been obtained, by the differential annealing technique, for the nuclei beyond the iron group to those within that group in the cosmic rays incident on the Moon. The natural t.l. of lunar samples has been used to estimate their effective storage temperature and mean depth below the surface. The results of the study of natural and artificially produced microcraters have been studied. (author)

  7. Studies of U in the blood of two population samples

    International Nuclear Information System (INIS)

    Segovia, N.; Olguin, M.E.; Romero, M.

    1986-01-01

    The present work, attempts to establish the statistical distribution of blood uranium in a population of the same community, similar in age and in living patterns. U traces were evaluated by a fission track technique both in whole blood and plasma samples. Dried samples were compressed into pellets and irradiated in a nuclear reactor using the external detector method. For U quantification, standard U samples were used. A comparative sampling of U content in blood samples from a group of radiation exposed workers and another of leukemia patients was also carried out. Results from the sampling groups are reported and discussed. (author)

  8. Optimization of sampling parameters for standardized exhaled breath sampling.

    Science.gov (United States)

    Doran, Sophie; Romano, Andrea; Hanna, George B

    2017-09-05

    The lack of standardization of breath sampling is a major contributing factor to the poor repeatability of results and hence represents a barrier to the adoption of breath tests in clinical practice. On-line and bag breath sampling have advantages but do not suit multicentre clinical studies whereas storage and robust transport are essential for the conduct of wide-scale studies. Several devices have been developed to control sampling parameters and to concentrate volatile organic compounds (VOCs) onto thermal desorption (TD) tubes and subsequently transport those tubes for laboratory analysis. We conducted three experiments to investigate (i) the fraction of breath sampled (whole vs. lower expiratory exhaled breath); (ii) breath sample volume (125, 250, 500 and 1000ml) and (iii) breath sample flow rate (400, 200, 100 and 50 ml/min). The target VOCs were acetone and potential volatile biomarkers for oesophago-gastric cancer belonging to the aldehyde, fatty acids and phenol chemical classes. We also examined the collection execution time and the impact of environmental contamination. The experiments showed that the use of exhaled breath-sampling devices requires the selection of optimum sampling parameters. The increase in sample volume has improved the levels of VOCs detected. However, the influence of the fraction of exhaled breath and the flow rate depends on the target VOCs measured. The concentration of potential volatile biomarkers for oesophago-gastric cancer was not significantly different between the whole and lower airway exhaled breath. While the recovery of phenols and acetone from TD tubes was lower when breath sampling was performed at a higher flow rate, other VOCs were not affected. A dedicated 'clean air supply' overcomes the contamination from ambient air, but the breath collection device itself can be a source of contaminants. In clinical studies using VOCs to diagnose gastro-oesophageal cancer, the optimum parameters are 500mls sample volume

  9. Groundwater-quality data in 12 GAMA study units: Results from the 2006–10 initial sampling period and the 2008–13 trend sampling period, California GAMA Priority Basin Project

    Science.gov (United States)

    Mathany, Timothy M.

    2017-03-09

    The Priority Basin Project (PBP) of the Groundwater Ambient Monitoring and Assessment (GAMA) program was developed in response to the Groundwater Quality Monitoring Act of 2001 and is being conducted by the U.S. Geological Survey in cooperation with the California State Water Resources Control Board. From 2004 through 2012, the GAMA-PBP collected samples and assessed the quality of groundwater resources that supply public drinking water in 35 study units across the State. Selected sites in each study unit were sampled again approximately 3 years after initial sampling as part of an assessment of temporal trends in water quality by the GAMA-PBP. Twelve of the study units, initially sampled during 2006–11 (initial sampling period) and sampled a second time during 2008–13 (trend sampling period) to assess temporal trends, are the subject of this report.The initial sampling was designed to provide a spatially unbiased assessment of the quality of untreated groundwater used for public water supplies in the 12 study units. In these study units, 550 sampling sites were selected by using a spatially distributed, randomized, grid-based method to provide spatially unbiased representation of the areas assessed (grid sites, also called “status sites”). After the initial sampling period, 76 of the previously sampled status sites (approximately 10 percent in each study unit) were randomly selected for trend sampling (“trend sites”). The 12 study units sampled both during the initial sampling and during the trend sampling period were distributed among 6 hydrogeologic provinces: Coastal (Northern and Southern), Transverse Ranges and Selected Peninsular Ranges, Klamath, Modoc Plateau and Cascades, and Sierra Nevada Hydrogeologic Provinces. For the purposes of this trend report, the six hydrogeologic provinces were grouped into two hydrogeologic regions based on location: Coastal and Mountain.The groundwater samples were analyzed for a number of synthetic organic

  10. An Experimental Study of Low-Temperature Sulfurization of Carbohydrates Using Various Sulfides Reveals Insights into Structural Characteristics and Sulfur Isotope Compositions of Macromolecular Organic Matter in the Environment

    Science.gov (United States)

    OBeirne, M. D.; Werne, J. P.; Van Dongen, B.; Gilhooly, W., III

    2017-12-01

    Sulfurization of carbohydrates has been suggested as an important mechanism for the preservation of organic matter in anoxic/euxinic depositional environments. In this study, glucose was sulfurized under laboratory conditions at room temperature (24°C) using three commercially available sulfides - ammonium sulfide ([NH4]2S), sodium sulfide (Na2S), and sodium hydrosulfide (NaHS), each mixed with elemental sulfur to produce polysulfide solutions. The reaction products were analyzed using Fourier transform infrared spectroscopy (FTIR), which revealed structural differences among the products formed via the three sulfide reactants. Additionally, analysis of the bulk sulfur isotope compositions of reactants and products was used to determine the fractionation(s) associated with abiotic sulfur incorporation into organic matter. Samples from both modern (Mahoney Lake, British Colombia, Canada) and ancient (Jurassic aged Blackstone Band from the Kimmeridge Clay Formation, Dorset, United Kingdom) euxinic systems were also analyzed for comparison to laboratory samples. Results from this study provide experimental evidence for the structural and sulfur isotopic relationships of sulfurized organic matter in the geosphere.

  11. On combining revealed and stated preferences to forecast customer behaviour: three case studies

    NARCIS (Netherlands)

    Ph.H.B.F. Franses (Philip Hans); P.C. Verhoef (Peter)

    2002-01-01

    textabstractMany companies collect stated preference data (SP) like intentions and satisfaction as well as revealed preference data (RP) like actual purchasing behavior. It seems relevant to examine the predictive usefulness of this information for future revealed preferences, that is, customer

  12. Evaluating sampling strategy for DNA barcoding study of coastal and inland halo-tolerant Poaceae and Chenopodiaceae: A case study for increased sample size.

    Directory of Open Access Journals (Sweden)

    Peng-Cheng Yao

    Full Text Available Environmental conditions in coastal salt marsh habitats have led to the development of specialist genetic adaptations. We evaluated six DNA barcode loci of the 53 species of Poaceae and 15 species of Chenopodiaceae from China's coastal salt marsh area and inland area. Our results indicate that the optimum DNA barcode was ITS for coastal salt-tolerant Poaceae and matK for the Chenopodiaceae. Sampling strategies for ten common species of Poaceae and Chenopodiaceae were analyzed according to optimum barcode. We found that by increasing the number of samples collected from the coastal salt marsh area on the basis of inland samples, the number of haplotypes of Arundinella hirta, Digitaria ciliaris, Eleusine indica, Imperata cylindrica, Setaria viridis, and Chenopodium glaucum increased, with a principal coordinate plot clearly showing increased distribution points. The results of a Mann-Whitney test showed that for Digitaria ciliaris, Eleusine indica, Imperata cylindrica, and Setaria viridis, the distribution of intraspecific genetic distances was significantly different when samples from the coastal salt marsh area were included (P < 0.01. These results suggest that increasing the sample size in specialist habitats can improve measurements of intraspecific genetic diversity, and will have a positive effect on the application of the DNA barcodes in widely distributed species. The results of random sampling showed that when sample size reached 11 for Chloris virgata, Chenopodium glaucum, and Dysphania ambrosioides, 13 for Setaria viridis, and 15 for Eleusine indica, Imperata cylindrica and Chenopodium album, average intraspecific distance tended to reach stability. These results indicate that the sample size for DNA barcode of globally distributed species should be increased to 11-15.

  13. Comparative study for essential elements determination in milk products samples by INAA and ICP-AES

    International Nuclear Information System (INIS)

    Kira, Carmen S.; Maihara, Vera A.

    2002-01-01

    The mineral elements Ca, Fe, K, Mg, Na and Zn were analyzed in milk products by using instrumental neutron activation analysis (INAA) and inductively coupled plasma atomic emission spectrometry (ICP-AES). The study included four types of cheese (mozzarella, minas, prato, parmesan), chocolate milk and yogurt. The samples were purchased from the local markets. Average concentrations ranged from 3668 (chocolate milk) to 16558 (parmesan cheese) mg/kg for Ca; from 2.61 (parmesan cheese) to 28.9 (chocolate milk) mg/kg for Fe; from 673 (mozzarella cheese) to 10492 (chocolate milk) mg/kg for K; from 398 (yogurt) to 2280 (minas cheese) mg/kg for Mg; from 1681 (yogurt) to 15248 (parmesan cheese) mg/kg for Na; from 12.1 (chocolate milk) to 71.8 (parmesan cheese) mg/kg for Zn. Two National Institute of Standards and Technology (NIST) standard reference materials (SRM 8435 Whole Milk Powder and SRM 1549 Non Fat Milk Powder) were analyzed to verify method accuracy. The statistic test used to determine the significance of the difference between the techniques was based on Unpaired t-Student test. Statistical test revealed no significance differences (P< 0,05) between the average values provided by the two methods for the most of determined elements. (author)

  14. Salivary gland tumours in a Mexican sample. A retrospective study.

    Science.gov (United States)

    Ledesma-Montes, C; Garces-Ortiz, M

    2002-01-01

    Salivary gland tumours are an important part of the Oral and Maxillofacial Pathology, unfortunately, only few studies on these tumours have been done in Latin-American population. The aim of this study was to compare demographic data on salivary gland tumours in a Mexican sample with those previously published from Latin American and non-Latin American countries. All cases of salivary gland tumours or lesions diagnosed in our service were reviewed. Of the reviewed cases,67 were confirmed as salivary gland tumours. Out of these 64.2% were benign neoplasms, 35.8% were malignant and a slight female predominance (56.7%) was found. The most common location was palate followed by lips and floor of the mouth. Mean age for benign tumours was 40.6 years with female predominance (60.5%). Mean age for malignant tumours was 41 years and female predominance was found again. Palate followed by retromolar area were the usual locations. Pleomorphic adenoma (58.2%), mucoepidermoid carcinoma (17.9%) and adenoid cystic carcinoma (11.9%) were the more frequent neoplasms. All retromolar cases were malignant and all submandibular gland tumours were benign. We found a high proportion of salivary gland neoplasms in children. Our results showed that differences of the studied tumours among our sample and previously reported series exist. These differences can be related to race and geographical location.

  15. Levels of metals in blood samples from Mallards (Anas platyrhynchos) from urban areas in Poland

    International Nuclear Information System (INIS)

    Binkowski, Łukasz J.; Meissner, Włodzimierz

    2013-01-01

    In this paper we present the studies conducted on blood samples taken from Mallards (Anas platyrhynchos). Birds were captured for ringing purposes (n = 43) in two small and two big towns (including highly urbanized areas). For comparison samples of blood from birds shot on fish ponds were used (n = 26). Based on the body mass all sampled individuals can be assessed as being in good condition. Levels of cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), nickel (Ni), lead (Pb) and zinc (Zn) in blood samples were measured with AAS. Concentrations of metals did not differ statistically between sexes and made up a following order: Fe > Zn > Cu > Cr ≈ Ni > Pb > Cd. Mallards from towns revealed lower concentrations of Zn and Cu but higher concentration of Fe. There was no difference in exposition to Pb between birds from towns and fish ponds. -- Highlights: •Concentrations of seven metals were measured in blood of Mallards. •Birds represent different kind of areas: urban (towns) and non-urban ones (fish ponds). •Concentrations of studied metals made up a following order: Fe > Zn > Cu > Cr ≈ Ni > Pb > Cd. •Birds from towns revealed higher amount of Fe and lower concentrations of Zn and Cu. •There was no difference in exposition to Pb between birds from towns and fish ponds. -- Exposition to iron is higher on industrialized areas in towns, but exposition to zinc and copper on such areas is lower in comparison to country fish ponds

  16. Procedures for sampling and sample reduction within quality assurance systems for solid biofuels

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    The objective of this experimental study on sampling was to determine the size and number of samples of biofuels required (taken at two sampling points in each case) and to compare two methods of sampling. The first objective of the sample-reduction exercise was to compare the reliability of various sampling methods, and the second objective was to measure the variations introduced as a result of reducing the sample size to form suitable test portions. The materials studied were sawdust, wood chips, wood pellets and bales of straw, and these were analysed for moisture, ash, particle size and chloride. The sampling procedures are described. The study was conducted in Scandinavia. The results of the study were presented in Leipzig in October 2004. The work was carried out as part of the UK's DTI Technology Programme: New and Renewable Energy.

  17. Studies on 129I and 14C in environmental samples by AMS

    International Nuclear Information System (INIS)

    Muramatsu, Yasuyuki

    2010-01-01

    We have carried out studies on 129 I and 14 C in environmental samples by AMS (accelerator mass spectrometry). In this paper summary of our results are described. Iodine is an essential element for humans and it pays an important role in thyroid gland. There are more than 30 isotopes of iodine. Among radioiodines 129 I has the longest half-life (1.57x10 7 y). This nuclide is released into the environment from nuclear weapons test, accidents of nuclear facilities (e.g. Chernobyl accident) and operation of spent fuel reprocessing plants. Since soil accumulates iodine, we have focused on the levels of both 129 I and 127 I in surface soils. In our previous studies, we used NAA (neutron activation analysis) for the determination. However, due to the limitation of its analytical sensitivity we could not detect 129 I in samples from background areas. In this study we have analyzed 129 I/ 127 I ratios by AMS and 127 I concentrations by ICP-MS (inductively coupled plasma spectrometry) after separation of iodine from soil by pyrohydrolysis and solvent extraction techniques. Using these methods, we have analyzed samples collected from different areas in Japan. Analytical results for surface soils collected from background areas were in the ranges 1.4 x 10 -5 - 4.6 x 10 -3 Bq/Kg as 129 I concentrations and 3.9 x 10 -11 - 3.0 x 10 -8 as 129 I/ 127 I ratios. The 129 I levels in Tokaimura, where a spent fuel reprocessing plant is located, were one to three orders of magnitude higher than those in background samples. The levels were higher in forest soils than those in field and rice paddy soils due to the interception effect of atmospheric 129 I by tree canopies. A wide range of stable iodine concentrations (0.4-143ppm) was observed. Rice paddy soils contained significantly lower iodine than forest and upland field soils. This should be explained by the desorption of iodine from the rice paddies due to microbial activities during the cultivation. Vertical distributions of 129 I

  18. Behaviours associated with weight loss maintenance and regaining in a Mediterranean population sample. A qualitative study.

    Science.gov (United States)

    Karfopoulou, E; Mouliou, K; Koutras, Y; Yannakoulia, M

    2013-10-01

    In the US, the National Weight Control Registry revealed lifestyle behaviours shared by weight loss maintainers. In the US and the UK, qualitative studies compared the experiences of weight loss maintainers and regainers. High rates of physical activity, a low-energy/low-fat diet, weight self-monitoring, breakfast consumption and flexible control of eating are well-established maintenance behaviours. The Mediterranean lifestyle has not been studied relative to weight loss maintenance. This study focused on a sample of Greek maintainers and regainers. Maintainers emphasized home-cooked meals; their diet does not appear to be low-fat, as home-cooked Greek meals are rich in olive oil. Having a small dinner is a common strategy among maintainers. Health motives were not mentioned by maintainers. Maintainers, but not regainers, appeared to compensate for emotional eating. Weight loss maintenance is imperative to successful obesity treatment. We qualitatively explored lifestyle behaviours associated with weight regulation, in a sample of Greek volunteers who had lost weight and either maintained or regained it. A 10% intentional loss maintained for at least one year was considered successful maintenance. Volunteers (n = 44, 41% men) formed eight focus groups, four of maintainers and four of regainers. Questions regarded weight loss, weight maintenance or regaining, and beliefs on weight maintenance and regaining. All discussions were tape recorded. Maintainers lost weight on their own, whereas regainers sought professional help. Maintainers exercised during both the loss and maintenance phases, whereas regainers showed inconsistent physical activity levels. Health motives for weight loss were mentioned only by regainers. Emotional eating was a common barrier, but only maintainers compensated for it. Maintainers continuously applied specific strategies to maintain their weight: emphasizing home-cooked meals, high eating frequency, a small dinner, portion size

  19. Improving the characterization of fish assemblage structure through the use of multiple sampling methods: a case study in a subtropical tidal flat ecosystem.

    Science.gov (United States)

    Contente, Riguel Feltrin; Del Bianco Rossi-Wongtschowski, Carmen Lucia

    2017-06-01

    The use of multiple sampling gears is indispensible to obtain robust characterizations of fish assemblage structure in species-rich subtropical ecosystems. In this study, such a dependence was demonstrated by characterizing the structure of the high-tide fish assemblage in a subtropical tidal flat ecosystem (the Araçá Bay, southeastern Brazil) using eight different gears along five seasonal surveys and estimating the bay's fish species richness, combining these data with those from local tide pool fish surveys. The high-tide fish assemblage was spatially structured, contained five threatened species, and was dominated by persistent and large populations of Eucinostomus argenteus and of the fisheries species Mugil curema and Diapterus rhombeus that intensively use the bay throughout their life cycles. Large, small-bodied fish populations supported a regular use of the bay by piscivores. The autumn-winter peak in abundance of juvenile fishes caused a subsequent increase in piscivore abundance, and both events explained the bulk of the seasonal variability of the fish assemblage. The estimated richness revealed that the combination of sampling methods was enough for sampling the bulk of the local richness, and the bay may hold a surprisingly high richness compared to other costal ecosystem of the region. This faunal characterization, only viable using multiple gears, will be critical to support the implementation of a future study to monitor the impacts on local fish biodiversity of an imminent port expansion over the tidal flat.

  20. Long-stay psychiatric patients: a prospective study revealing persistent antipsychotic-induced movement disorder.

    Directory of Open Access Journals (Sweden)

    P Roberto Bakker

    Full Text Available OBJECTIVE: The purpose of this study was to assess the frequency of persistent drug-induced movement disorders namely, tardive dyskinesia (TD, parkinsonism, akathisia and tardive dystonia in a representative sample of long-stay patients with chronic severe mental illness. METHOD: Naturalistic study of 209, mainly white, antipsychotic-treated patients, mostly diagnosed with psychotic disorder. Of this group, the same rater examined 194 patients at least two times over a 4-year period, with a mean follow-up time of 1.1 years, with validated scales for TD, parkinsonism, akathisia, and tardive dystonia. RESULTS: The frequencies of persistent movement disorders in the sample were 28.4% for TD, 56.2% for parkinsonism, 4.6% for akathisia and 5.7% for tardive dystonia. Two-thirds of the participants displayed at least one type of persistent movement disorder. CONCLUSIONS: Persistent movement disorder continues to be the norm for long-stay patients with chronic mental illness and long-term antipsychotic treatment. Measures are required to remedy this situation.

  1. Gene expression analysis of skin grafts and cultured keratinocytes using synthetic RNA normalization reveals insights into differentiation and growth control.

    Science.gov (United States)

    Katayama, Shintaro; Skoog, Tiina; Jouhilahti, Eeva-Mari; Siitonen, H Annika; Nuutila, Kristo; Tervaniemi, Mari H; Vuola, Jyrki; Johnsson, Anna; Lönnerberg, Peter; Linnarsson, Sten; Elomaa, Outi; Kankuri, Esko; Kere, Juha

    2015-06-25

    Keratinocytes (KCs) are the most frequent cells in the epidermis, and they are often isolated and cultured in vitro to study the molecular biology of the skin. Cultured primary cells and various immortalized cells have been frequently used as skin models but their comparability to intact skin has been questioned. Moreover, when analyzing KC transcriptomes, fluctuation of polyA+ RNA content during the KCs' lifecycle has been omitted. We performed STRT RNA sequencing on 10 ng samples of total RNA from three different sample types: i) epidermal tissue (split-thickness skin grafts), ii) cultured primary KCs, and iii) HaCaT cell line. We observed significant variation in cellular polyA+ RNA content between tissue and cell culture samples of KCs. The use of synthetic RNAs and SAMstrt in normalization enabled comparison of gene expression levels in the highly heterogenous samples and facilitated discovery of differences between the tissue samples and cultured cells. The transcriptome analysis sensitively revealed genes involved in KC differentiation in skin grafts and cell cycle regulation related genes in cultured KCs and emphasized the fluctuation of transcription factors and non-coding RNAs associated to sample types. The epidermal keratinocytes derived from tissue and cell culture samples showed highly different polyA+ RNA contents. The use of SAMstrt and synthetic RNA based normalization allowed the comparison between tissue and cell culture samples and thus proved to be valuable tools for RNA-seq analysis with translational approach. Transciptomics revealed clear difference both between tissue and cell culture samples and between primary KCs and immortalized HaCaT cells.

  2. Mapping species distributions with MAXENT using a geographically biased sample of presence data: a performance assessment of methods for correcting sampling bias.

    Science.gov (United States)

    Fourcade, Yoan; Engler, Jan O; Rödder, Dennis; Secondi, Jean

    2014-01-01

    MAXENT is now a common species distribution modeling (SDM) tool used by conservation practitioners for predicting the distribution of a species from a set of records and environmental predictors. However, datasets of species occurrence used to train the model are often biased in the geographical space because of unequal sampling effort across the study area. This bias may be a source of strong inaccuracy in the resulting model and could lead to incorrect predictions. Although a number of sampling bias correction methods have been proposed, there is no consensual guideline to account for it. We compared here the performance of five methods of bias correction on three datasets of species occurrence: one "virtual" derived from a land cover map, and two actual datasets for a turtle (Chrysemys picta) and a salamander (Plethodon cylindraceus). We subjected these datasets to four types of sampling biases corresponding to potential types of empirical biases. We applied five correction methods to the biased samples and compared the outputs of distribution models to unbiased datasets to assess the overall correction performance of each method. The results revealed that the ability of methods to correct the initial sampling bias varied greatly depending on bias type, bias intensity and species. However, the simple systematic sampling of records consistently ranked among the best performing across the range of conditions tested, whereas other methods performed more poorly in most cases. The strong effect of initial conditions on correction performance highlights the need for further research to develop a step-by-step guideline to account for sampling bias. However, this method seems to be the most efficient in correcting sampling bias and should be advised in most cases.

  3. Molecular profiling of synchronous and metachronous cancers of the pancreas reveal molecular mimicry between samples from the same patient.

    Science.gov (United States)

    Talbott, Vanessa A; Yeo, Charles J; Brody, Jonathan R; Witkiewicz, Agnieszka K

    2012-07-01

    Pancreatic ductal adenocarcinoma (PDA) is rarely a survivable disease. In rare cases, separate synchronous tumors are discovered at the time of resection, while in others, patients present with a metachronous cancer after prior surgical resection. Studying molecular markers of synchronous and metachronous lesions may aid to clarify the biology of this often deadly disease. Two patients presented with synchronous tumors (each one with a tumor in the pancreatic head/neck and the other in the tail, designated patients A and B). An additional patient (patient C) underwent an R0 resection for PDA of the head and recurred 1.5 y later with PDA in the tail. Genomic DNA was laser capture microdissected (LCM) from the tumor and molecular analysis was performed. K-ras status and loss of heterozygosity (LOH) were determined from multiple specimens for each case. All samples from each patient harbored identical K-ras mutations. In patient A, the tumor at the head of the pancreas had more clonal genetic instability as reflected by LOH analysis over multiple LCM samples. Patient B had more genetic instability in the tail lesion compared with the neck. Patient C had virtually the identical molecular profile in both tumors, supporting the notion that both tumors were related. We conclude that the synchronous and metachronous tumors likely are initiated from identical precursor lesions and/or events (i.e., K-ras mutations). Future studies will need to investigate if these tumors will respond similarly to adjuvant therapies targeted against the clonal molecular events in the tumor. Copyright © 2012 Elsevier Inc. All rights reserved.

  4. Respondent-Driven Sampling – Testing Assumptions: Sampling with Replacement

    Directory of Open Access Journals (Sweden)

    Barash Vladimir D.

    2016-03-01

    Full Text Available Classical Respondent-Driven Sampling (RDS estimators are based on a Markov Process model in which sampling occurs with replacement. Given that respondents generally cannot be interviewed more than once, this assumption is counterfactual. We join recent work by Gile and Handcock in exploring the implications of the sampling-with-replacement assumption for bias of RDS estimators. We differ from previous studies in examining a wider range of sampling fractions and in using not only simulations but also formal proofs. One key finding is that RDS estimates are surprisingly stable even in the presence of substantial sampling fractions. Our analyses show that the sampling-with-replacement assumption is a minor contributor to bias for sampling fractions under 40%, and bias is negligible for the 20% or smaller sampling fractions typical of field applications of RDS.

  5. Genotyping faecal samples of Bengal tiger Panthera tigris tigris for population estimation: A pilot study

    Directory of Open Access Journals (Sweden)

    Singh Lalji

    2006-10-01

    Full Text Available Abstract Background Bengal tiger Panthera tigris tigris the National Animal of India, is an endangered species. Estimating populations for such species is the main objective for designing conservation measures and for evaluating those that are already in place. Due to the tiger's cryptic and secretive behaviour, it is not possible to enumerate and monitor its populations through direct observations; instead indirect methods have always been used for studying tigers in the wild. DNA methods based on non-invasive sampling have not been attempted so far for tiger population studies in India. We describe here a pilot study using DNA extracted from faecal samples of tigers for the purpose of population estimation. Results In this study, PCR primers were developed based on tiger-specific variations in the mitochondrial cytochrome b for reliably identifying tiger faecal samples from those of sympatric carnivores. Microsatellite markers were developed for the identification of individual tigers with a sibling Probability of Identity of 0.005 that can distinguish even closely related individuals with 99.9% certainty. The effectiveness of using field-collected tiger faecal samples for DNA analysis was evaluated by sampling, identification and subsequently genotyping samples from two protected areas in southern India. Conclusion Our results demonstrate the feasibility of using tiger faecal matter as a potential source of DNA for population estimation of tigers in protected areas in India in addition to the methods currently in use.

  6. Study of Bacterial Samples Using Laser Induced Breakdown Spectroscopy

    International Nuclear Information System (INIS)

    Farooq W A; Atif M; Tawfik W; Alsalhi M S; Alahmed Z A; Sarfraz M; Singh J P

    2014-01-01

    Laser-induced breakdown spectroscopy (LIBS) technique has been applied to investigate two different types of bacteria, Escherichia coli (B1) and Micrococcus luteus (B2) deposited on glass slides using Spectrolaser 7000. LIBS spectra were analyzed using spectrolaser software. LIBS spectrum of glass substrate was compared with bacteria spectra. Ca, Mg, Na, K, P, S, Cl, Fe, Al, Mn, Cu, C, H and CN-band appeared in bacterial samples in air. Two carbon lines at 193.02 nm, 247.88 nm and one hydrogen line at 656.28 nm with intensity ratios of 1.9, 1.83 and 1.53 appeared in bacterial samples B1 and B2 respectively. Carbon and hydrogen are the important components of the bio-samples like bacteria and other cancer cells. Investigation on LIBS spectra of the samples in He and Ar atmospheres is also presented. Ni lines appeared only in B2 sample in Ar atmosphere. From the present experimental results we are able to show that LIBS technique has a potential in the identification and discrimination of different types of bacteria. (plasma technology)

  7. 3-dimensional examination of the adult mouse subventricular zone reveals lineage-specific microdomains.

    Science.gov (United States)

    Azim, Kasum; Fiorelli, Roberto; Zweifel, Stefan; Hurtado-Chong, Anahi; Yoshikawa, Kazuaki; Slomianka, Lutz; Raineteau, Olivier

    2012-01-01

    Recent studies suggest that the subventricular zone (SVZ) of the lateral ventricle is populated by heterogeneous populations of stem and progenitor cells that, depending on their exact location, are biased to acquire specific neuronal fates. This newly described heterogeneity of SVZ stem and progenitor cells underlines the necessity to develop methods for the accurate quantification of SVZ stem and progenitor subpopulations. In this study, we provide 3-dimensional topographical maps of slow cycling "stem" cells and progenitors based on their unique cell cycle properties. These maps revealed that both cell populations are present throughout the lateral ventricle wall as well as in discrete regions of the dorsal wall. Immunodetection of transcription factors expressed in defined progenitor populations further reveals that divergent lineages have clear regional enrichments in the rostro-caudal as well as in the dorso-ventral span of the lateral ventricle. Thus, progenitors expressing Tbr2 and Dlx2 were confined to dorsal and dorso-lateral regions of the lateral ventricle, respectively, while Mash1+ progenitors were more homogeneously distributed. All cell populations were enriched in the rostral-most region of the lateral ventricle. This diversity and uneven distribution greatly impede the accurate quantification of SVZ progenitor populations. This is illustrated by measuring the coefficient of error of estimates obtained by using increasing section sampling interval. Based on our empirical data, we provide such estimates for all progenitor populations investigated in this study. These can be used in future studies as guidelines to judge if the precision obtained with a sampling scheme is sufficient to detect statistically significant differences between experimental groups if a biological effect is present. Altogether, our study underlines the need to consider the SVZ of the lateral ventricle as a complex 3D structure and define methods to accurately assess neural

  8. A sample cell to study hydrate formation with x-ray scattering

    International Nuclear Information System (INIS)

    Conrad, Heiko; Lehmkuehler, Felix; Sternemann, Christian; Feroughi, Omid; Tolan, Metin; Simonelli, Laura; Huotari, Simo

    2009-01-01

    We present a new sample cell for measuring nonresonant inelastic x-ray scattering spectra of a tetrahydrofuran (THF)-water liquid mixture and THF hydrate. The hydrate is formed inside the cell after nucleation seeds have been offered by a special magnetic stirring mechanism. Hydrate formation was verified by wide angle x-ray scattering and nonresonant x-ray Raman scattering spectra at the oxygen K-edge. A broad range of scattering angles can be studied with this cell which is necessary for momentum transfer dependent inelastic x-ray scattering. This cell is ideal to examine other liquid hydrate formers or other liquid samples, which have to be mixed in situ during the measurements.

  9. Ad-Hoc vs. Standardized and Optimized Arthropod Diversity Sampling

    Directory of Open Access Journals (Sweden)

    Pedro Cardoso

    2009-09-01

    Full Text Available The use of standardized and optimized protocols has been recently advocated for different arthropod taxa instead of ad-hoc sampling or sampling with protocols defined on a case-by-case basis. We present a comparison of both sampling approaches applied for spiders in a natural area of Portugal. Tests were made to their efficiency, over-collection of common species, singletons proportions, species abundance distributions, average specimen size, average taxonomic distinctness and behavior of richness estimators. The standardized protocol revealed three main advantages: (1 higher efficiency; (2 more reliable estimations of true richness; and (3 meaningful comparisons between undersampled areas.

  10. Determination of 226Ra by gamma spectrometry: study of packaging vial of sample for analysis

    International Nuclear Information System (INIS)

    Carneiro, Andre Cavalcanti

    2015-01-01

    Determination of radioactivity levels of 226 Ra by gamma spectrometry in a sample is based on measurements of 214 Pb and 214 Bi, daughters of 222 Rn. Because radon is a gas, it can leak from the sample vial or accumulate on the upper empty it. If the vial has any crack, there will be loss of gas, which will cause error in determining the 226 Ra concentration. One possible cause of cracks in the vials, that houses standards and samples, is the radiolysis action in the vial material, usually a polymer. As the demand 226 Ra analysis in different matrices (geological samples, food, plants, etc.) is increasing, it was decided to study some polymer vials available on the market, to verify the feasibility to be used when is applied the analysis method using gamma spectrometry. Four types of polymer vials have been studied. The radiation doses in walls of the vials caused by natural radionuclides present in the sample were simulated using gamma irradiation. Tests, such as compressive strength test and tightness, were applied to the irradiated and non-irradiated vials. First, to verify the effect of radiolysis on the vial material and also if there was 222 Rn diffusion in their walls. These preliminary results pointed out that the acrylic vials are the best option of packaging samples for analysis. This study should be repeated in a larger number of samples for a better evaluation. (author)

  11. The 4-vessel Sampling Approach to Integrative Studies of Human Placental Physiology In Vivo.

    Science.gov (United States)

    Holme, Ane M; Holm, Maia B; Roland, Marie C P; Horne, Hildegunn; Michelsen, Trond M; Haugen, Guttorm; Henriksen, Tore

    2017-08-02

    The human placenta is highly inaccessible for research while still in utero. The current understanding of human placental physiology in vivo is therefore largely based on animal studies, despite the high diversity among species in placental anatomy, hemodynamics and duration of the pregnancy. The vast majority of human placenta studies are ex vivo perfusion studies or in vitro trophoblast studies. Although in vitro studies and animal models are essential, extrapolation of the results from such studies to the human placenta in vivo is uncertain. We aimed to study human placenta physiology in vivo at term, and present a detailed protocol of the method. Exploiting the intraabdominal access to the uterine vein just before the uterine incision during planned cesarean section, we collect blood samples from the incoming and outgoing vessels on the maternal and fetal sides of the placenta. When combining concentration measurements from blood samples with volume blood flow measurements, we are able to quantify placental and fetal uptake and release of any compound. Furthermore, placental tissue samples from the same mother-fetus pairs can provide measurements of transporter density and activity and other aspects of placental functions in vivo. Through this integrative use of the 4-vessel sampling method we are able to test some of the current concepts of placental nutrient transfer and metabolism in vivo, both in normal and pathological pregnancies. Furthermore, this method enables the identification of substances secreted by the placenta to the maternal circulation, which could be an important contribution to the search for biomarkers of placenta dysfunction.

  12. Sampling soils for 137Cs using various field-sampling volumes

    International Nuclear Information System (INIS)

    Nyhan, J.W.; Schofield, T.G.; White, G.C.; Trujillo, G.

    1981-10-01

    The sediments from a liquid effluent receiving area at the Los Alamos National Laboratory and soils from intensive study area in the fallout pathway of Trinity were sampled for 137 Cs using 25-, 500-, 2500-, and 12 500-cm 3 field sampling volumes. A highly replicated sampling program was used to determine mean concentrations and inventories of 137 Cs at each site, as well as estimates of spatial, aliquoting, and counting variance components of the radionuclide data. The sampling methods were also analyzed as a function of soil size fractions collected in each field sampling volume and of the total cost of the program for a given variation in the radionuclide survey results. Coefficients of variation (CV) of 137 Cs inventory estimates ranged from 0.063 to 0.14 for Mortandad Canyon sediments, where CV values for Trinity soils were observed from 0.38 to 0.57. Spatial variance components of 137 Cs concentration data were usually found to be larger than either the aliquoting or counting variance estimates and were inversely related to field sampling volume at the Trinity intensive site. Subsequent optimization studies of the sampling schemes demonstrated that each aliquot should be counted once, and that only 2 to 4 aliquots out of an many as 30 collected need be assayed for 137 Cs. The optimization studies showed that as sample costs increased to 45 man-hours of labor per sample, the variance of the mean 137 Cs concentration decreased dramatically, but decreased very little with additional labor

  13. Studying the sampling representativeness in the NPP ventilation ducts

    International Nuclear Information System (INIS)

    Sosnovskij, R.I.; Fedchenko, T.K.; Minin, S.A.

    2000-01-01

    Measurements of the gas and aerosol voluminous activity in the NPP ventilation ducts are an important source of information on the radiation contaminants ingress into the environmental medium. These measurements include sampling, samples transport and proper measurements. The work is devoted to calculation of metrological characteristics of the sampling systems for the NPP gas-aerosol releases by different parameters of these systems and ventilation ducts. The results obtained are intended for application by designing such systems and their metrological certification [ru

  14. Hierarchical sampling of multiple strata: an innovative technique in exposure characterization

    International Nuclear Information System (INIS)

    Ericson, J.E.; Gonzalez, Elisabeth J.

    2003-01-01

    Sampling of multiple strata, or hierarchical sampling of various exposure sources and activity areas, has been tested and is suggested as a method to sample (or to locate) areas with a high prevalence of elevated blood lead in children. Hierarchical sampling was devised to supplement traditional soil lead sampling of a single stratum, either residential or fixed point source, using a multistep strategy. Blood lead (n=1141) and soil lead (n=378) data collected under the USEPA/UCI Tijuana Lead Project (1996-1999) were analyzed to evaluate the usefulness of sampling soil lead from background sites, schools and parks, point sources, and residences. Results revealed that industrial emissions have been a contributing factor to soil lead contamination in Tijuana. At the regional level, point source soil lead was associated with mean blood lead levels and concurrent high background, and point source soil lead levels were predictive of a high percentage of subjects with blood lead equal to or greater than 10 μg/dL (pe 10). Significant relationships were observed between mean blood lead level and fixed point source soil lead (r=0.93; P 2 =0.72 using a quadratic model) and between residential soil lead and fixed point source soil lead (r=0.90; P 2 =0.86 using a cubic model). This study suggests that point sources alone are not sufficient for predicting the relative risk of exposure to lead in the urban environment. These findings will be useful in defining regions for targeted or universal soil lead sampling by site type. Point sources have been observed to be predictive of mean blood lead at the regional level; however, this relationship alone was not sufficient to predict pe 10. It is concluded that when apparently undisturbed sites reveal high soil lead levels in addition to local point sources, dispersion of lead is widespread and will be associated with a high prevalence of elevated blood lead in children. Multiple strata sampling was shown to be useful in

  15. Fine-scale genetic structure and cryptic associations reveal evidence of kin-based sociality in the African forest elephant.

    Directory of Open Access Journals (Sweden)

    Stephanie G Schuttler

    Full Text Available Spatial patterns of relatedness within animal populations are important in the evolution of mating and social systems, and have the potential to reveal information on species that are difficult to observe in the wild. This study examines the fine-scale genetic structure and connectivity of groups within African forest elephants, Loxodonta cyclotis, which are often difficult to observe due to forest habitat. We tested the hypothesis that genetic similarity will decline with increasing geographic distance, as we expect kin to be in closer proximity, using spatial autocorrelation analyses and Tau K(r tests. Associations between individuals were investigated through a non-invasive genetic capture-recapture approach using network models, and were predicted to be more extensive than the small groups found in observational studies, similar to fission-fusion sociality found in African savanna (Loxodonta africana and Asian (Elephas maximus species. Dung samples were collected in Lopé National Park, Gabon in 2008 and 2010 and genotyped at 10 microsatellite loci, genetically sexed, and sequenced at the mitochondrial DNA control region. We conducted analyses on samples collected at three different temporal scales: a day, within six-day sampling sessions, and within each year. Spatial autocorrelation and Tau K(r tests revealed genetic structure, but results were weak and inconsistent between sampling sessions. Positive spatial autocorrelation was found in distance classes of 0-5 km, and was strongest for the single day session. Despite weak genetic structure, individuals within groups were significantly more related to each other than to individuals between groups. Social networks revealed some components to have large, extensive groups of up to 22 individuals, and most groups were composed of individuals of the same matriline. Although fine-scale population genetic structure was weak, forest elephants are typically found in groups consisting of kin and

  16. Study of probe-sample distance for biomedical spectra measurement

    Directory of Open Access Journals (Sweden)

    Li Lei

    2011-11-01

    Full Text Available Abstract Background Fiber-based optical spectroscopy has been widely used for biomedical applications. However, the effect of probe-sample distance on the collection efficiency has not been well investigated. Method In this paper, we presented a theoretical model to maximize the illumination and collection efficiency in designing fiber optic probes for biomedical spectra measurement. This model was in general applicable to probes with single or multiple fibers at an arbitrary incident angle. In order to demonstrate the theory, a fluorescence spectrometer was used to measure the fluorescence of human finger skin at various probe-sample distances. The fluorescence spectrum and the total fluorescence intensity were recorded. Results The theoretical results show that for single fiber probes, contact measurement always provides the best results. While for multi-fiber probes, there is an optimal probe distance. When a 400- μm excitation fiber is used to deliver the light to the skin and another six 400- μm fibers surrounding the excitation fiber are used to collect the fluorescence signal, the experimental results show that human finger skin has very strong fluorescence between 475 nm and 700 nm under 450 nm excitation. The fluorescence intensity is heavily dependent on the probe-sample distance and there is an optimal probe distance. Conclusions We investigated a number of probe-sample configurations and found that contact measurement could be the primary choice for single-fiber probes, but was very inefficient for multi-fiber probes. There was an optimal probe-sample distance for multi-fiber probes. By carefully choosing the probe-sample distance, the collection efficiency could be enhanced by 5-10 times. Our experiments demonstrated that the experimental results of the probe-sample distance dependence of collection efficiency in multi-fiber probes were in general agreement with our theory.

  17. Planning Considerations for a Mars Sample Receiving Facility: Summary and Interpretation of Three Design Studies

    Science.gov (United States)

    Beaty, David W.; Allen, Carlton C.; Bass, Deborah S.; Buxbaum, Karen L.; Campbell, James K.; Lindstrom, David J.; Miller, Sylvia L.; Papanastassiou, Dimitri A.

    2009-10-01

    It has been widely understood for many years that an essential component of a Mars Sample Return mission is a Sample Receiving Facility (SRF). The purpose of such a facility would be to take delivery of the flight hardware that lands on Earth, open the spacecraft and extract the sample container and samples, and conduct an agreed-upon test protocol, while ensuring strict containment and contamination control of the samples while in the SRF. Any samples that are found to be non-hazardous (or are rendered non-hazardous by sterilization) would then be transferred to long-term curation. Although the general concept of an SRF is relatively straightforward, there has been considerable discussion about implementation planning. The Mars Exploration Program carried out an analysis of the attributes of an SRF to establish its scope, including minimum size and functionality, budgetary requirements (capital cost, operating costs, cost profile), and development schedule. The approach was to arrange for three independent design studies, each led by an architectural design firm, and compare the results. While there were many design elements in common identified by each study team, there were significant differences in the way human operators were to interact with the systems. In aggregate, the design studies provided insight into the attributes of a future SRF and the complex factors to consider for future programmatic planning.

  18. [Mutism and acute behavioral disorders revealing MELAS syndrome].

    Science.gov (United States)

    Coomans, H; Barroso, B; Bertandeau, E; Bonnan, M; Dakar, A; Demasles, S; Garraud, S; Krim, E; Martin-Négrier, M-L

    2011-11-01

    MELAS syndrome (mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes) is a rare genetic mitochondrial disease which can cause cerebral (cerebrovascular accident, migraine, mental deterioration..), sensorial (bilateral symmetrical deafness) and peripheral (muscular involvement, neuropathy) disorders potentially associated with diabetes, renal or cardiac disorders, or growth retardation. Eighty percent of the patients have the 3243 A>G mutation in the leucine RNA transfer gene. Clinical manifestations leading to discovery of the mutation can be extremely varied, affecting patients of different age groups. We report the case of a 49-year-old man who presented acute fits of confusion followed by mutism and praxic disorders. History taking revealed recently diagnosed type 2 diabetes, axonal neuropathy, and bilateral symmetrical deafness requiring hearing aids. The initial MRI showed FLAIR sequences with bi-parietal abnormalities, no signs of recent stroke on the DW/B10000 sequences, and basal ganglia calcifications. Blood tests and morphological findings ruled out a vascular origin. Search for lactic acidosis remained constantly negative in blood samples despite positive cerebrospinal fluid samples (N×3). The 3243 A>G mitochondrial DNA mutation was identified. The neuropsychological evaluation revealed a serious dysexecutive syndrome with a major impact on the patient's self sufficiency. Neurocognitive disorders are not common in MELAS syndrome. Brain MRI results and the presence of extra-neurological signs can be helpful for diagnosis. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  19. Effect of dissolved organic matter on pre-equilibrium passive sampling: A predictive QSAR modeling study.

    Science.gov (United States)

    Lin, Wei; Jiang, Ruifen; Shen, Yong; Xiong, Yaxin; Hu, Sizi; Xu, Jianqiao; Ouyang, Gangfeng

    2018-04-13

    Pre-equilibrium passive sampling is a simple and promising technique for studying sampling kinetics, which is crucial to determine the distribution, transfer and fate of hydrophobic organic compounds (HOCs) in environmental water and organisms. Environmental water samples contain complex matrices that complicate the traditional calibration process for obtaining the accurate rate constants. This study proposed a QSAR model to predict the sampling rate constants of HOCs (polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and pesticides) in aqueous systems containing complex matrices. A homemade flow-through system was established to simulate an actual aqueous environment containing dissolved organic matter (DOM) i.e. humic acid (HA) and (2-Hydroxypropyl)-β-cyclodextrin (β-HPCD)), and to obtain the experimental rate constants. Then, a quantitative structure-activity relationship (QSAR) model using Genetic Algorithm-Multiple Linear Regression (GA-MLR) was found to correlate the experimental rate constants to the system state including physicochemical parameters of the HOCs and DOM which were calculated and selected as descriptors by Density Functional Theory (DFT) and Chem 3D. The experimental results showed that the rate constants significantly increased as the concentration of DOM increased, and the enhancement factors of 70-fold and 34-fold were observed for the HOCs in HA and β-HPCD, respectively. The established QSAR model was validated as credible (R Adj. 2 =0.862) and predictable (Q 2 =0.835) in estimating the rate constants of HOCs for complex aqueous sampling, and a probable mechanism was developed by comparison to the reported theoretical study. The present study established a QSAR model of passive sampling rate constants and calibrated the effect of DOM on the sampling kinetics. Copyright © 2018 Elsevier B.V. All rights reserved.

  20. Reliability of different sampling densities for estimating and mapping lichen diversity in biomonitoring studies

    International Nuclear Information System (INIS)

    Ferretti, M.; Brambilla, E.; Brunialti, G.; Fornasier, F.; Mazzali, C.; Giordani, P.; Nimis, P.L.

    2004-01-01

    Sampling requirements related to lichen biomonitoring include optimal sampling density for obtaining precise and unbiased estimates of population parameters and maps of known reliability. Two available datasets on a sub-national scale in Italy were used to determine a cost-effective sampling density to be adopted in medium-to-large-scale biomonitoring studies. As expected, the relative error in the mean Lichen Biodiversity (Italian acronym: BL) values and the error associated with the interpolation of BL values for (unmeasured) grid cells increased as the sampling density decreased. However, the increase in size of the error was not linear and even a considerable reduction (up to 50%) in the original sampling effort led to a far smaller increase in errors in the mean estimates (<6%) and in mapping (<18%) as compared with the original sampling densities. A reduction in the sampling effort can result in considerable savings of resources, which can then be used for a more detailed investigation of potentially problematic areas. It is, however, necessary to decide the acceptable level of precision at the design stage of the investigation, so as to select the proper sampling density. - An acceptable level of precision must be decided before determining a sampling design

  1. Use of Dried Capillary Blood Sampling for Islet Autoantibody Screening in Relatives: A Feasibility Study.

    Science.gov (United States)

    Bingley, Polly J; Rafkin, Lisa E; Matheson, Della; Steck, Andrea K; Yu, Liping; Henderson, Courtney; Beam, Craig A; Boulware, David C

    2015-12-01

    Islet autoantibody testing provides the basis for assessment of risk of progression to type 1 diabetes. We set out to determine the feasibility and acceptability of dried capillary blood spot-based screening to identify islet autoantibody-positive relatives potentially eligible for inclusion in prevention trials. Dried blood spot (DBS) and venous samples were collected from 229 relatives participating in the TrialNet Pathway to Prevention Study. Both samples were tested for glutamic acid decarboxylase, islet antigen 2, and zinc transporter 8 autoantibodies, and venous samples were additionally tested for insulin autoantibodies and islet cell antibodies. We defined multiple autoantibody positive as two or more autoantibodies in venous serum and DBS screen positive if one or more autoantibodies were detected. Participant questionnaires compared the sample collection methods. Of 44 relatives who were multiple autoantibody positive in venous samples, 42 (95.5%) were DBS screen positive, and DBS accurately detected 145 of 147 autoantibody-negative relatives (98.6%). Capillary blood sampling was perceived as more painful than venous blood draw, but 60% of participants would prefer initial screening using home fingerstick with clinic visits only required if autoantibodies were found. Capillary blood sampling could facilitate screening for type 1 diabetes prevention studies.

  2. Treatability studies on different refinery wastewater samples using high-throughput microbial electrolysis cells (MECs)

    KAUST Repository

    Ren, Lijiao; Siegert, Michael; Ivanov, Ivan; Pisciotta, John M.; Logan, Bruce E.

    2013-01-01

    High-throughput microbial electrolysis cells (MECs) were used to perform treatability studies on many different refinery wastewater samples all having appreciably different characteristics, which resulted in large differences in current generation. A de-oiled refinery wastewater sample from one site (DOW1) produced the best results, with 2.1±0.2A/m2 (maximum current density), 79% chemical oxygen demand removal, and 82% headspace biological oxygen demand removal. These results were similar to those obtained using domestic wastewater. Two other de-oiled refinery wastewater samples also showed good performance, with a de-oiled oily sewer sample producing less current. A stabilization lagoon sample and a stripped sour wastewater sample failed to produce appreciable current. Electricity production, organics removal, and startup time were improved when the anode was first acclimated to domestic wastewater. These results show mini-MECs are an effective method for evaluating treatability of different wastewaters. © 2013 Elsevier Ltd.

  3. Treatability studies on different refinery wastewater samples using high-throughput microbial electrolysis cells (MECs)

    KAUST Repository

    Ren, Lijiao

    2013-05-01

    High-throughput microbial electrolysis cells (MECs) were used to perform treatability studies on many different refinery wastewater samples all having appreciably different characteristics, which resulted in large differences in current generation. A de-oiled refinery wastewater sample from one site (DOW1) produced the best results, with 2.1±0.2A/m2 (maximum current density), 79% chemical oxygen demand removal, and 82% headspace biological oxygen demand removal. These results were similar to those obtained using domestic wastewater. Two other de-oiled refinery wastewater samples also showed good performance, with a de-oiled oily sewer sample producing less current. A stabilization lagoon sample and a stripped sour wastewater sample failed to produce appreciable current. Electricity production, organics removal, and startup time were improved when the anode was first acclimated to domestic wastewater. These results show mini-MECs are an effective method for evaluating treatability of different wastewaters. © 2013 Elsevier Ltd.

  4. NMR-Based Metabonomic Investigation of Heat Stress in Myotubes Reveals a Time-Dependent Change in the Metabolites

    DEFF Research Database (Denmark)

    Straadt, Ida K; Young, Jette F; Bross, Peter

    2010-01-01

    NMR-based metabonomics was applied to elucidate the time-dependent stress responses in mouse myotubes after heat exposure of either 42 or 45 degrees C for 1 h. Principal component analysis (PCA) revealed that the gradual time-dependent changes in metabolites contributing to the clustering...... and separation of the control samples from the different time points after heat stress primarily are in the metabolites glucose, leucine, lysine, phenylalanine, creatine, glutamine, and acetate. In addition, PC scores revealed a maximum change in metabolite composition 4 h after the stress exposure; thereafter......, samples returned toward control samples, however, without reaching the control samples even 10 h after stress. The results also indicate that the myotubes efficiently regulate the pH level by release of lactate to the culture medium at a heat stress level of 42 degrees C, which is a temperature level...

  5. Detection of Mycoplasma synoviae in clinical samples by VlhA-PCR method

    Directory of Open Access Journals (Sweden)

    H Ansari

    2010-02-01

    Full Text Available As one of the major pathogens of avian species, Mycoplasma Synoviae causes significant economic losses to the poultry industry. The main purpose of this study was to detect Mycoplasma Synoviae in clinical samples using the VlhA-PCR method. For serological screening test, 373 serum samples were collected from 25 breeder farms and rapid serum agglutination test conducted which revealed that 143 samples equivalent to 19 breeder farms were positive. For VlhA-PCR assay, 20 of the previously mentioned breeder farms were selected and sterile swab were collected from the palatine cleft, trachea, air sacs and lungs. Three swabs from 3 birds were placed in a test tube containing 1 ml of PBS and transferred to the laboratory for PCR test. Specific primers for VIhA gene were employed in this study. The PCR product from specific primers showed 350-400 bp for all field isolated on electrophoresis gel in 8 farms. VlhA-PCR with high sensitivity could be employed in definitive diagnosis of Mycoplasma Synoviae infection in the laboratory.

  6. Comparison of POCIS passive samplers vs. composite water sampling: A case study.

    Science.gov (United States)

    Criquet, Justine; Dumoulin, David; Howsam, Michael; Mondamert, Leslie; Goossens, Jean-François; Prygiel, Jean; Billon, Gabriel

    2017-12-31

    The relevance of Polar Organic Chemical Integrative Samplers (POCIS) was evaluated for the assessment of concentrations of 46 pesticides and 19 pharmaceuticals in a small, peri-urban river with multi-origin inputs. Throughout the period of POCIS deployment, 24h-average water samples were collected automatically, and showed the rapid temporal evolution of concentrations of several micropollutants, as well as permitting the calculation of average concentrations in the water phase for comparison with those estimated from POCIS passive samplers. In the daily water samples, cyproconazol, epoxyconazol and imidacloprid showed high temporal variations with concentrations ranging from under the limit of detection up to several hundreds of ngL -1 . Erythromycin, cyprofloxacin and iopromide also increased rapidly up to tens of ngL -1 within a few days. Conversely, atrazine, caffeine, diclofenac, and to a lesser extent carbamazepine and sucralose, were systematically present in the water samples and showed limited variation in concentrations. For most of the substances studied here, the passive samplers gave reliable average concentrations between the minimal and maximal daily concentrations during the time of deployment. For pesticides, a relatively good correlation was clearly established (R 2 =0.89) between the concentrations obtained by POCIS and those gained from average water samples. A slight underestimation of the concentration by POCIS can be attributed to inappropriate sampling rates extracted from the literature and for our system, and new values are proposed. Considering the all data set, 75% of the results indicate a relatively good agreement between the POCIS and the average water samples concentration (values of the ratio ranging between 0,33 and 3). Note further that this agreement between these concentrations remains valid considering different sampling rates extracted from the literature. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Genetic genealogy reveals true Y haplogroup of House of Bourbon contradicting recent identification of the presumed remains of two French Kings.

    Science.gov (United States)

    Larmuseau, Maarten H D; Delorme, Philippe; Germain, Patrick; Vanderheyden, Nancy; Gilissen, Anja; Van Geystelen, Anneleen; Cassiman, Jean-Jacques; Decorte, Ronny

    2014-05-01

    Genetic analysis strongly increases the opportunity to identify skeletal remains or other biological samples from historical figures. However, validation of this identification is essential and should be done by DNA typing of living relatives. Based on the similarity of a limited set of Y-STRs, a blood sample and a head were recently identified as those belonging respectively to King Louis XVI and his paternal ancestor King Henry IV. Here, we collected DNA samples from three living males of the House of Bourbon to validate the since then controversial identification of these remains. The three living relatives revealed the Bourbon's Y-chromosomal variant on a high phylogenetic resolution for several members of the lineage between Henry IV and Louis XVI. This 'true' Bourbon's variant is different from the published Y-STR profiles of the blood as well as of the head. The earlier identifications of these samples can therefore not be validated. Moreover, matrilineal genealogical data revealed that the published mtDNA sequence of the head was also different from the one of a series of relatives. This therefore leads to the conclusion that the analyzed samples were not from the French kings. Our study once again demonstrated that in order to realize an accurate genetic identification of historical remains DNA typing of living persons, who are paternally or maternally related with the presumed donor of the samples, is required.

  8. Sampling and farm stories prompt consumers to buy specialty cheeses

    OpenAIRE

    Reed, Barbara A.; Bruhn, Christine M.

    2003-01-01

    California specialty cheese makers need information on what drives product sales so they can effectively market their products. Focus group and telephone research revealed that specialty cheese consumers have a strong preference for sampling cheese before making a purchase. Consumers also rely heavily on staff recommendations to select cheese. They appreciate unlimited sampling in an unhurried, low-pressure environment. Specialty cheese consumers consider themselves “food experimenters”; they...

  9. Screening of a long-term sample set reveals two Ranavirus lineages in British herpetofauna.

    Directory of Open Access Journals (Sweden)

    Stephen J Price

    Full Text Available Reports of severe disease outbreaks in amphibian communities in mainland Europe due to strains of the common midwife toad virus (CMTV-like clade of Ranavirus are increasing and have created concern due to their considerable population impacts. In Great Britain, viruses in another clade of Ranavirus-frog virus 3 (FV3-like-have caused marked declines of common frog (Rana temporaria populations following likely recent virus introductions. The British public has been reporting mortality incidents to a citizen science project since 1992, with carcasses submitted for post-mortem examination, resulting in a long-term tissue archive spanning 25 years. We screened this archive for ranavirus (458 individuals from 228 incidents using molecular methods and undertook preliminary genotyping of the ranaviruses detected. In total, ranavirus was detected in 90 individuals from 41 incidents focused in the north and south of England. The majority of detections involved common frogs (90% but also another anuran, a caudate and a reptile. Most incidents were associated with FV3-like viruses but two, separated by 300 km and 16 years, involved CMTV-like viruses. These British CMTV-like viruses were more closely related to ranaviruses from mainland Europe than to each other and were estimated to have diverged at least 458 years ago. This evidence of a CMTV-like virus in Great Britain in 1995 represents the earliest confirmed case of a CMTV associated with amphibians and raises important questions about the history of ranavirus in Great Britain and the epidemiology of CMTV-like viruses. Despite biases present in the opportunistic sample used, this study also demonstrates the role of citizen science projects in generating resources for research and the value of maintaining long-term wildlife tissue archives.

  10. Aerial sampling using drones for measuring trace gases

    Science.gov (United States)

    Chang, Chih-Chung; Wang, Jia-Lin; Chang, Chih-Yuan; Lin, Ming-Ren; Ou-Yang, Chang-Feng; Pan, Xiang-Xu; Lin, Neng-Huei

    2017-04-01

    Aerial and ground-level samples were simultaneously collected at the northern tip of Taiwan, Cape Fuguei, which is commonly served as a receptor site to receive air parcels from East Asia, Asian continent, the northwest Pacific Ocean and the island of Taiwan itself. Both aerial and surface samples were analyzed for 106 volatile organic compounds (VOCs) and divided into three categories as follows: 1. the total concentrations of 106 VOC (T-VOC) at 300-m height that are lower than the T-VOC level at the surface (Category A), 2. T-VOC concentrations at 300-m that are higher than those at the surface (Category B), and 3. comparable concentrations (Category C). Ten VOCs were exploited as tracers for a variety of emission sources linking to possible sources and transport routes of airborne pollutants. The first two categories A and B showed significant differences in the observed composition and concentrations of tracers between aerial and ground-level samples, implying that the pollutants at different heights may have resulted from different sources and poor air mixing, despite only a 300-m difference in vertical height. In contrast, Category C showed good vertical mixing, as indicated by the comparable concentrations between the aerial and surface measurements. Since the three categories occurred in specific meteorological conditions (between, prior to, and after cold fronts), respectively, it suggests that varied prevailing meteorology controlled the distribution and transport of airborne pollutants. Unlike sampling commonly performed at the surface, this study uses aerial sampling to demonstrate that layered structures under different meteorological conditions. Sampling aloft in lower boundary layer avoids samples being over-influenced by the close-by surface sources such as traffic to reveal signatures of a broader region.

  11. High rates of hybridisation reveal fragile reproductive barriers between endangered Australian sea snakes

    DEFF Research Database (Denmark)

    Sanders, Kate L; Redsted Rasmussen, Arne; Guinea, Michael L.

    2014-01-01

    designations, but revealed high frequencies of hybrids on all four reefs and individuals of pure A. fuscus ancestry only at Scott and (historically) Ashmore. Most unexpectedly, 95% of snakes sampled at Hibernia were hybrids that resembled A. laevis in phenotype, revealing a collapse of reproductive barriers...... (‘reverse speciation’) at this reef. These results have dire implications for the conservation status of A. fuscus, and highlight the fragility of reproductive barriers in a recent marine radiation....

  12. Sputum microbiota in tuberculosis as revealed by 16S rRNA pyrosequencing.

    Directory of Open Access Journals (Sweden)

    Man Kit Cheung

    Full Text Available BACKGROUND: Tuberculosis (TB remains a global threat in the 21st century. Traditional studies of the disease are focused on the single pathogen Mycobacterium tuberculosis. Recent studies have revealed associations of some diseases with an imbalance in the microbial community. Characterization of the TB microbiota could allow a better understanding of the disease. METHODOLOGY/PRINCIPAL FINDINGS: Here, the sputum microbiota in TB infection was examined by using 16S rRNA pyrosequencing. A total of 829,873 high-quality sequencing reads were generated from 22 TB and 14 control sputum samples. Firmicutes, Proteobacteria, Bacteroidetes, Actinobacteria, and Fusobacteria were the five major bacterial phyla recovered, which together composed over 98% of the microbial community. Proteobacteria and Bacteroidetes were more represented in the TB samples and Firmicutes was more predominant in the controls. Sixteen major bacterial genera were recovered. Streptococcus, Neisseria and Prevotella were the most predominant genera, which were dominated by several operational taxonomic units grouped at a 97% similarity level. Actinomyces, Fusobacterium, Leptotrichia, Prevotella, Streptococcus, and Veillonella were found in all TB samples, possibly representing the core genera in TB sputum microbiota. The less represented genera Mogibacterium, Moryella and Oribacterium were enriched statistically in the TB samples, while a genus belonging to the unclassified Lactobacillales was enriched in the controls. The diversity of microbiota was similar in the TB and control samples. CONCLUSIONS/SIGNIFICANCE: The composition and diversity of sputum microbiota in TB infection was characterized for the first time by using high-throughput pyrosequencing. It lays the framework for examination of potential roles played by the diverse microbiota in TB pathogenesis and progression, and could ultimately facilitate advances in TB treatment.

  13. Rapid immunohistochemical diagnosis of tobacco mosaic virus disease by microwave-assisted plant sample preparation

    Science.gov (United States)

    Zellnig, Günther; Möstl, Stefan; Zechmann, Bernd

    2013-01-01

    Immunoelectron microscopy is a powerful method to diagnose viral diseases and to study the distribution of the viral agent within plant cells and tissues. Nevertheless, current protocols for the immunological detection of viral diseases with transmission electron microscopy (TEM) in plants take between 3 and 6 days and are therefore not suited for rapid diagnosis of virus diseases in plants. In this study, we describe a method that allows rapid cytohistochemical detection of tobacco mosaic virus (TMV) in leaves of tobacco plants. With the help of microwave irradiation, sample preparation of the leaves was reduced to 90 min. After sample sectioning, virus particles were stained on the sections by immunogold labelling of the viral coat protein, which took 100 min. After investigation with the TEM, a clear visualization of TMV in tobacco cells was achieved altogether in about half a day. Comparison of gold particle density by image analysis revealed that samples prepared with the help of microwave irradiation yielded significantly higher gold particle density as samples prepared conventionally at room temperature. This study clearly demonstrates that microwave-assisted plant sample preparation in combination with cytohistochemical localization of viral coat protein is well suited for rapid diagnosis of plant virus diseases in altogether about half a day by TEM. PMID:23580761

  14. Challenges of biological sample preparation for SIMS imaging of elements and molecules at subcellular resolution

    International Nuclear Information System (INIS)

    Chandra, Subhash

    2008-01-01

    Secondary ion mass spectrometry (SIMS) based imaging techniques capable of subcellular resolution characterization of elements and molecules are becoming valuable tools in many areas of biology and medicine. Due to high vacuum requirements of SIMS, the live cells cannot be analyzed directly in the instrument. The sample preparation, therefore, plays a critical role in preserving the native chemical composition for SIMS analysis. This work focuses on the evaluation of frozen-hydrated and frozen freeze-dried sample preparations for SIMS studies of cultured cells with a CAMECA IMS-3f dynamic SIMS ion microscope instrument capable of producing SIMS images with a spatial resolution of 500 nm. The sandwich freeze-fracture method was used for fracturing the cells. The complimentary fracture planes in the plasma membrane were characterized by field-emission secondary electron microscopy (FESEM) in the frozen-hydrated state. The cells fractured at the dorsal surface were used for SIMS analysis. The frozen-hydrated SIMS analysis of individual cells under dynamic primary ion beam (O 2 + ) revealed local secondary ion signal enhancements correlated with the water image signals of 19 (H 3 O) + . A preferential removal of water from the frozen cell matrix in the Z-axis was also observed. These complications render the frozen-hydrated sample type less desirable for subcellular dynamic SIMS studies. The freeze-drying of frozen-hydrated cells, either inside the instrument or externally in a freeze-drier, allowed SIMS imaging of subcellular chemical composition. Morphological evaluations of fractured freeze-dried cells with SEM and confocal laser scanning microscopy (CLSM) revealed well-preserved mitochondria, Golgi apparatus, and stress fibers. SIMS analysis of fractured freeze-dried cells revealed well-preserved chemical composition of even the most highly diffusible ions like K + and Na + in physiologically relevant concentrations. The high K-low Na signature in individual cells

  15. Challenges of biological sample preparation for SIMS imaging of elements and molecules at subcellular resolution

    Science.gov (United States)

    Chandra, Subhash

    2008-12-01

    Secondary ion mass spectrometry (SIMS) based imaging techniques capable of subcellular resolution characterization of elements and molecules are becoming valuable tools in many areas of biology and medicine. Due to high vacuum requirements of SIMS, the live cells cannot be analyzed directly in the instrument. The sample preparation, therefore, plays a critical role in preserving the native chemical composition for SIMS analysis. This work focuses on the evaluation of frozen-hydrated and frozen freeze-dried sample preparations for SIMS studies of cultured cells with a CAMECA IMS-3f dynamic SIMS ion microscope instrument capable of producing SIMS images with a spatial resolution of 500 nm. The sandwich freeze-fracture method was used for fracturing the cells. The complimentary fracture planes in the plasma membrane were characterized by field-emission secondary electron microscopy (FESEM) in the frozen-hydrated state. The cells fractured at the dorsal surface were used for SIMS analysis. The frozen-hydrated SIMS analysis of individual cells under dynamic primary ion beam (O 2+) revealed local secondary ion signal enhancements correlated with the water image signals of 19(H 3O) +. A preferential removal of water from the frozen cell matrix in the Z-axis was also observed. These complications render the frozen-hydrated sample type less desirable for subcellular dynamic SIMS studies. The freeze-drying of frozen-hydrated cells, either inside the instrument or externally in a freeze-drier, allowed SIMS imaging of subcellular chemical composition. Morphological evaluations of fractured freeze-dried cells with SEM and confocal laser scanning microscopy (CLSM) revealed well-preserved mitochondria, Golgi apparatus, and stress fibers. SIMS analysis of fractured freeze-dried cells revealed well-preserved chemical composition of even the most highly diffusible ions like K + and Na + in physiologically relevant concentrations. The high K-low Na signature in individual cells

  16. Influence of salinity stress on the height and productivity features of durum wheat samples in different phases of vegetation

    Directory of Open Access Journals (Sweden)

    A. Z. Sikhmuradov

    2010-01-01

    Full Text Available Influence of salinity stress on the morphological features of durum wheat in different phases of vegetation is studied in the work. It is revealed that in earlier phases the samples have weak stability, but further salt-stability increases.

  17. Sampling design and procedures for fixed surface-water sites in the Georgia-Florida coastal plain study unit, 1993

    Science.gov (United States)

    Hatzell, H.H.; Oaksford, E.T.; Asbury, C.E.

    1995-01-01

    The implementation of design guidelines for the National Water-Quality Assessment (NAWQA) Program has resulted in the development of new sampling procedures and the modification of existing procedures commonly used in the Water Resources Division of the U.S. Geological Survey. The Georgia-Florida Coastal Plain (GAFL) study unit began the intensive data collection phase of the program in October 1992. This report documents the implementation of the NAWQA guidelines by describing the sampling design and procedures for collecting surface-water samples in the GAFL study unit in 1993. This documentation is provided for agencies that use water-quality data and for future study units that will be entering the intensive phase of data collection. The sampling design is intended to account for large- and small-scale spatial variations, and temporal variations in water quality for the study area. Nine fixed sites were selected in drainage basins of different sizes and different land-use characteristics located in different land-resource provinces. Each of the nine fixed sites was sampled regularly for a combination of six constituent groups composed of physical and chemical constituents: field measurements, major ions and metals, nutrients, organic carbon, pesticides, and suspended sediments. Some sites were also sampled during high-flow conditions and storm events. Discussion of the sampling procedure is divided into three phases: sample collection, sample splitting, and sample processing. A cone splitter was used to split water samples for the analysis of the sampling constituent groups except organic carbon from approximately nine liters of stream water collected at four fixed sites that were sampled intensively. An example of the sample splitting schemes designed to provide the sample volumes required for each sample constituent group is described in detail. Information about onsite sample processing has been organized into a flowchart that describes a pathway for each of

  18. Likelihood inference of non-constant diversification rates with incomplete taxon sampling.

    Science.gov (United States)

    Höhna, Sebastian

    2014-01-01

    Large-scale phylogenies provide a valuable source to study background diversification rates and investigate if the rates have changed over time. Unfortunately most large-scale, dated phylogenies are sparsely sampled (fewer than 5% of the described species) and taxon sampling is not uniform. Instead, taxa are frequently sampled to obtain at least one representative per subgroup (e.g. family) and thus to maximize diversity (diversified sampling). So far, such complications have been ignored, potentially biasing the conclusions that have been reached. In this study I derive the likelihood of a birth-death process with non-constant (time-dependent) diversification rates and diversified taxon sampling. Using simulations I test if the true parameters and the sampling method can be recovered when the trees are small or medium sized (fewer than 200 taxa). The results show that the diversification rates can be inferred and the estimates are unbiased for large trees but are biased for small trees (fewer than 50 taxa). Furthermore, model selection by means of Akaike's Information Criterion favors the true model if the true rates differ sufficiently from alternative models (e.g. the birth-death model is recovered if the extinction rate is large and compared to a pure-birth model). Finally, I applied six different diversification rate models--ranging from a constant-rate pure birth process to a decreasing speciation rate birth-death process but excluding any rate shift models--on three large-scale empirical phylogenies (ants, mammals and snakes with respectively 149, 164 and 41 sampled species). All three phylogenies were constructed by diversified taxon sampling, as stated by the authors. However only the snake phylogeny supported diversified taxon sampling. Moreover, a parametric bootstrap test revealed that none of the tested models provided a good fit to the observed data. The model assumptions, such as homogeneous rates across species or no rate shifts, appear to be

  19. Sampling Development

    Science.gov (United States)

    Adolph, Karen E.; Robinson, Scott R.

    2011-01-01

    Research in developmental psychology requires sampling at different time points. Accurate depictions of developmental change provide a foundation for further empirical studies and theories about developmental mechanisms. However, overreliance on widely spaced sampling intervals in cross-sectional and longitudinal designs threatens the validity of…

  20. Study of gastric cancer samples using terahertz techniques

    Science.gov (United States)

    Wahaia, Faustino; Kasalynas, Irmantas; Seliuta, Dalius; Molis, Gediminas; Urbanowicz, Andrzej; Carvalho Silva, Catia D.; Carneiro, Fatima; Valusis, Gintaras; Granja, Pedro L.

    2014-08-01

    In the present work, samples of healthy and adenocarcinoma-affected human gastric tissue were analyzed using transmission time-domain THz spectroscopy (THz-TDS) and spectroscopic THz imaging at 201 and 590 GHz. The work shows that it is possible to distinguish between normal and cancerous regions in dried and paraffin-embedded samples. Plots of absorption coefficient α and refractive index n of normal and cancer affected tissues, as well as 2-D transmission THz images are presented and the conditions for discrimination between normal and affected tissues are discussed.

  1. High Throughput qPCR Expression Profiling of Circulating MicroRNAs Reveals Minimal Sex- and Sample Timing-Related Variation in Plasma of Healthy Volunteers.

    Directory of Open Access Journals (Sweden)

    Catherine Mooney

    Full Text Available MicroRNAs are a class of small non-coding RNA that regulate gene expression at a post-transcriptional level. MicroRNAs have been identified in various body fluids under normal conditions and their stability as well as their dysregulation in disease opens up a new field for biomarker study. However, diurnal and day-to-day variation in plasma microRNA levels, and differential regulation between males and females, may affect biomarker stability. A QuantStudio 12K Flex Real-Time PCR System was used to profile plasma microRNA levels using OpenArray in male and female healthy volunteers, in the morning and afternoon, and at four time points over a one month period. Using this system we were able to run four OpenArray plates in a single run, the equivalent of 32 traditional 384-well qPCR plates or 12,000 data points. Up to 754 microRNAs can be identified in a single plasma sample in under two hours. 108 individual microRNAs were identified in at least 80% of all our samples which compares favourably with other reports of microRNA profiles in serum or plasma in healthy adults. Many of these microRNAs, including miR-16-5p, miR-17-5p, miR-19a-3p, miR-24-3p, miR-30c-5p, miR-191-5p, miR-223-3p and miR-451a are highly expressed and consistent with previous studies using other platforms. Overall, microRNA levels were very consistent between individuals, males and females, and time points and we did not detect significant differences in levels of microRNAs. These results suggest the suitability of this platform for microRNA profiling and biomarker discovery and suggest minimal confounding influence of sex or sample timing. However, the platform has not been subjected to rigorous validation which must be demonstrated in future biomarker studies where large differences may exist between disease and control samples.

  2. Evaluating leaf litter beetle data sampled by Winkler extraction from Atlantic forest sites in southern Brazil

    Directory of Open Access Journals (Sweden)

    Philipp Werner Hopp

    2011-06-01

    Full Text Available Evaluating leaf litter beetle data sampled by Winkler extraction from Atlantic forest sites in southern Brazil. To evaluate the reliability of data obtained by Winkler extraction in Atlantic forest sites in southern Brazil, we studied litter beetle assemblages in secondary forests (5 to 55 years after abandonment and old-growth forests at two seasonally different points in time. For all regeneration stages, species density and abundance were lower in April compared to August; but, assemblage composition of the corresponding forest stages was similar in both months. We suggest that sampling of small litter inhabiting beetles at different points in time using the Winkler technique reveals identical ecological patterns, which are more likely to be influenced by sample incompleteness than by differences in their assemblage composition. A strong relationship between litter quantity and beetle occurrences indicates the importance of this variable for the temporal species density pattern. Additionally, the sampled beetle material was compared with beetle data obtained with pitfall traps in one old-growth forest. Over 60% of the focal species captured with pitfall traps were also sampled by Winkler extraction in different forest stages. Few beetles with a body size too large to be sampled by Winkler extraction were only sampled with pitfall traps. This indicates that the local litter beetle fauna is dominated by small species. Hence, being aware of the exclusion of large beetles and beetle species occurring during the wet season, the Winkler method reveals a reliable picture of the local leaf litter beetle community.

  3. Inter-laboratory exercise on steroid estrogens in aqueous samples

    Energy Technology Data Exchange (ETDEWEB)

    Heath, E., E-mail: ester.heath@ijs.s [Department of Environmental Sciences, Jozef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia); Kosjek, T. [Department of Environmental Sciences, Jozef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia); Andersen, H.R.; Holten Luetzhoft, H.-C. [Department of Environmental Engineering, Technical University of Denmark, Miljoevej 113, DK-2800 Kgs. Lyngby (Denmark); Adolfson Erici, M. [Stockholm University, ITM SE-106 91 Stockholm (Sweden); Coquery, M. [Cemagref, U.R. QELY, F-69336 Lyon (France); Duering, R.-A. [Giessen University, Institute of Soil Science and Soil Conservation, Giessen (Germany); Gans, O. [Umweltbundesamt GmbH, Unit Organic Analysis, Spittelauer Laende 5, 1090 Vienna (Austria); Guignard, C. [CRP Gabriel Lippmann, EVA, 41 rue du Brill, L-4422 Belvaux (Luxembourg); Karlsson, P. [Lantmannen Analycen AB, Research and Development, Sjoehagsgatan 3 Box 905, 5319, Lidkoeping (Sweden); Manciot, F. [CAE VEOLIA ENVIRONMENT, 1 Place de Turenne, 94417 Saint Maurice Cedex (France); Moldovan, Z. [National Institute of Research and Development for Isotopic and Molecular Technology, Mass Spectrometry Department, Str. Donath 65-103, 400293 Cluj-Napoca (Romania); Patureau, D. [INRA, UR50, Laboratoire de Biotechnologie de l' Environnemet (LBE), Avenue des etangs, F-11100 Narbonne (France); Cruceru, L. [Pollution Control Department, National Research Institute for Industrial Ecology (ECOIND), Sos.Panduri 90-92, sector 5, Bucharest (Romania); Sacher, F. [DVGW-Technologiezentrum Wasser, Karlsruher Strasse 84, 76139 Karlsruhe (Germany); Ledin, A. [Department of Environmental Engineering, Technical University of Denmark, Miljoevej 113, DK-2800 Kgs. Lyngby (Denmark)

    2010-03-15

    An inter-laboratory comparison exercise was organized among European laboratories, under the aegis of EU COST Action 636: 'Xenobiotics in Urban Water Cycle'. The objective was to evaluate the performance of testing laboratories determining 'Endocrine Disrupting Compounds' (EDC) in various aqueous matrices. As the main task three steroid estrogens: 17alpha-ethinylestradiol, 17beta-estradiol and estrone were determined in four spiked aqueous matrices: tap water, river water and wastewater treatment plant influent and effluent using GC-MS and LC-MS/MS. Results were compared and discussed according to the analytical techniques applied, the accuracy and reproducibility of the analytical methods and the nature of the sample matrices. Overall, the results obtained in this inter-laboratory exercise reveal a high level of competence among the participating laboratories for the detection of steroid estrogens in water samples indicating that GC-MS as well as LC-MS/MS can equally be employed for the analysis of natural and synthetic hormones. - Herein are presented the results of the first international inter-laboratory study on determination of selected steroid hormones in environmental aqueous samples.

  4. Comparison of Two Surface Contamination Sampling Techniques Conducted for the Characterization of Two Pajarito Site Manhattan Project National Historic Park Properties

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, Tammy Ann [Montana Tech of the Univ. of Montana, Butte, MT (United States); Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-07-29

    Technical Area-18 (TA-18), also known as Pajarito Site, is located on Los Alamos National Laboratory property and has historic buildings that will be included in the Manhattan Project National Historic Park. Characterization studies of metal contamination were needed in two of the four buildings that are on the historic registry in this area, a “battleship” bunker building (TA-18-0002) and the Pond cabin (TA-18-0029). However, these two buildings have been exposed to the elements, are decades old, and have porous and rough surfaces (wood and concrete). Due to these conditions, it was questioned whether standard wipe sampling would be adequate to detect surface dust metal contamination in these buildings. Thus, micro-vacuum and surface wet wipe sampling techniques were performed side-by-side at both buildings and results were compared statistically. A two-tail paired t-test revealed that the micro-vacuum and wet wipe techniques were statistically different for both buildings. Further mathematical analysis revealed that the wet wipe technique picked up more metals from the surface than the microvacuum technique. Wet wipes revealed concentrations of beryllium and lead above internal housekeeping limits; however, using an yttrium normalization method with linear regression analysis between beryllium and yttrium revealed a correlation indicating that the beryllium levels were likely due to background and not operational contamination. PPE and administrative controls were implemented for National Park Service (NPS) and Department of Energy (DOE) tours as a result of this study. Overall, this study indicates that the micro-vacuum technique may not be an efficient technique to sample for metal dust contamination.

  5. Selection bias in population-based cancer case-control studies due to incomplete sampling frame coverage.

    Science.gov (United States)

    Walsh, Matthew C; Trentham-Dietz, Amy; Gangnon, Ronald E; Nieto, F Javier; Newcomb, Polly A; Palta, Mari

    2012-06-01

    Increasing numbers of individuals are choosing to opt out of population-based sampling frames due to privacy concerns. This is especially a problem in the selection of controls for case-control studies, as the cases often arise from relatively complete population-based registries, whereas control selection requires a sampling frame. If opt out is also related to risk factors, bias can arise. We linked breast cancer cases who reported having a valid driver's license from the 2004-2008 Wisconsin women's health study (N = 2,988) with a master list of licensed drivers from the Wisconsin Department of Transportation (WDOT). This master list excludes Wisconsin drivers that requested their information not be sold by the state. Multivariate-adjusted selection probability ratios (SPR) were calculated to estimate potential bias when using this driver's license sampling frame to select controls. A total of 962 cases (32%) had opted out of the WDOT sampling frame. Cases age <40 (SPR = 0.90), income either unreported (SPR = 0.89) or greater than $50,000 (SPR = 0.94), lower parity (SPR = 0.96 per one-child decrease), and hormone use (SPR = 0.93) were significantly less likely to be covered by the WDOT sampling frame (α = 0.05 level). Our results indicate the potential for selection bias due to differential opt out between various demographic and behavioral subgroups of controls. As selection bias may differ by exposure and study base, the assessment of potential bias needs to be ongoing. SPRs can be used to predict the direction of bias when cases and controls stem from different sampling frames in population-based case-control studies.

  6. Outpatient Tinnitus Clinic, Self-Help Web Platform, or Mobile Application to Recruit Tinnitus Study Samples?

    Directory of Open Access Journals (Sweden)

    Thomas Probst

    2017-04-01

    Full Text Available For understanding the heterogeneity of tinnitus, large samples are required. However, investigations on how samples recruited by different methods differ from each other are lacking. In the present study, three large samples each recruited by different means were compared: N = 5017 individuals registered at a self-help web platform for tinnitus (crowdsourcing platform Tinnitus Talk, N = 867 users of a smart mobile application for tinnitus (crowdsensing platform TrackYourTinnitus, and N = 3786 patients contacting an outpatient tinnitus clinic (Tinnitus Center of the University Hospital Regensburg. The three samples were compared regarding age, gender, and duration of tinnitus (month or years perceiving tinnitus; subjective report using chi-squared tests. The three samples significantly differed from each other in age, gender and tinnitus duration (p < 0.05. Users of the TrackYourTinnitus crowdsensing platform were younger, users of the Tinnitus Talk crowdsourcing platform had more often female gender, and users of both newer technologies (crowdsourcing and crowdsensing had more frequently acute/subacute tinnitus (<3 months and 4–6 months as well as a very long tinnitus duration (>20 years. The implications of these findings for clinical research are that newer technologies such as crowdsourcing and crowdsensing platforms offer the possibility to reach individuals hard to get in contact with at an outpatient tinnitus clinic. Depending on the aims and the inclusion/exclusion criteria of a given study, different recruiting strategies (clinic and/or newer technologies offer different advantages and disadvantages. In general, the representativeness of study results might be increased when tinnitus study samples are recruited in the clinic as well as via crowdsourcing and crowdsensing.

  7. Ocular-following responses to white noise stimuli in humans reveal a novel nonlinearity that results from temporal sampling.

    Science.gov (United States)

    Sheliga, Boris M; Quaia, Christian; FitzGibbon, Edmond J; Cumming, Bruce G

    2016-01-01

    White noise stimuli are frequently used to study the visual processing of broadband images in the laboratory. A common goal is to describe how responses are derived from Fourier components in the image. We investigated this issue by recording the ocular-following responses (OFRs) to white noise stimuli in human subjects. For a given speed we compared OFRs to unfiltered white noise with those to noise filtered with band-pass filters and notch filters. Removing components with low spatial frequency (SF) reduced OFR magnitudes, and the SF associated with the greatest reduction matched the SF that produced the maximal response when presented alone. This reduction declined rapidly with SF, compatible with a winner-take-all operation. Removing higher SF components increased OFR magnitudes. For higher speeds this effect became larger and propagated toward lower SFs. All of these effects were quantitatively well described by a model that combined two factors: (a) an excitatory drive that reflected the OFRs to individual Fourier components and (b) a suppression by higher SF channels where the temporal sampling of the display led to flicker. This nonlinear interaction has an important practical implication: Even with high refresh rates (150 Hz), the temporal sampling introduced by visual displays has a significant impact on visual processing. For instance, we show that this distorts speed tuning curves, shifting the peak to lower speeds. Careful attention to spectral content, in the light of this nonlinearity, is necessary to minimize the resulting artifact when using white noise patterns undergoing apparent motion.

  8. Sampling and sample processing in pesticide residue analysis.

    Science.gov (United States)

    Lehotay, Steven J; Cook, Jo Marie

    2015-05-13

    Proper sampling and sample processing in pesticide residue analysis of food and soil have always been essential to obtain accurate results, but the subject is becoming a greater concern as approximately 100 mg test portions are being analyzed with automated high-throughput analytical methods by agrochemical industry and contract laboratories. As global food trade and the importance of monitoring increase, the food industry and regulatory laboratories are also considering miniaturized high-throughput methods. In conjunction with a summary of the symposium "Residues in Food and Feed - Going from Macro to Micro: The Future of Sample Processing in Residue Analytical Methods" held at the 13th IUPAC International Congress of Pesticide Chemistry, this is an opportune time to review sampling theory and sample processing for pesticide residue analysis. If collected samples and test portions do not adequately represent the actual lot from which they came and provide meaningful results, then all costs, time, and efforts involved in implementing programs using sophisticated analytical instruments and techniques are wasted and can actually yield misleading results. This paper is designed to briefly review the often-neglected but crucial topic of sample collection and processing and put the issue into perspective for the future of pesticide residue analysis. It also emphasizes that analysts should demonstrate the validity of their sample processing approaches for the analytes/matrices of interest and encourages further studies on sampling and sample mass reduction to produce a test portion.

  9. Comparing identified and statistically significant lipids and polar metabolites in 15-year old serum and dried blood spot samples for longitudinal studies: Comparing lipids and metabolites in serum and DBS samples

    Energy Technology Data Exchange (ETDEWEB)

    Kyle, Jennifer E. [Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland WA USA; Casey, Cameron P. [Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland WA USA; Stratton, Kelly G. [National Security Directorate, Pacific Northwest National Laboratory, Richland WA USA; Zink, Erika M. [Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland WA USA; Kim, Young-Mo [Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland WA USA; Zheng, Xueyun [Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland WA USA; Monroe, Matthew E. [Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland WA USA; Weitz, Karl K. [Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland WA USA; Bloodsworth, Kent J. [Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland WA USA; Orton, Daniel J. [Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland WA USA; Ibrahim, Yehia M. [Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland WA USA; Moore, Ronald J. [Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland WA USA; Lee, Christine G. [Department of Medicine, Bone and Mineral Unit, Oregon Health and Science University, Portland OR USA; Research Service, Portland Veterans Affairs Medical Center, Portland OR USA; Pedersen, Catherine [Department of Medicine, Bone and Mineral Unit, Oregon Health and Science University, Portland OR USA; Orwoll, Eric [Department of Medicine, Bone and Mineral Unit, Oregon Health and Science University, Portland OR USA; Smith, Richard D. [Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland WA USA; Burnum-Johnson, Kristin E. [Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland WA USA; Baker, Erin S. [Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland WA USA

    2017-02-05

    The use of dried blood spots (DBS) has many advantages over traditional plasma and serum samples such as smaller blood volume required, storage at room temperature, and ability for sampling in remote locations. However, understanding the robustness of different analytes in DBS samples is essential, especially in older samples collected for longitudinal studies. Here we analyzed DBS samples collected in 2000-2001 and stored at room temperature and compared them to matched serum samples stored at -80°C to determine if they could be effectively used as specific time points in a longitudinal study following metabolic disease. Four hundred small molecules were identified in both the serum and DBS samples using gas chromatograph-mass spectrometry (GC-MS), liquid chromatography-MS (LC-MS) and LC-ion mobility spectrometry-MS (LC-IMS-MS). The identified polar metabolites overlapped well between the sample types, though only one statistically significant polar metabolite in a case-control study was conserved, indicating degradation occurs in the DBS samples affecting quantitation. Differences in the lipid identifications indicated that some oxidation occurs in the DBS samples. However, thirty-six statistically significant lipids correlated in both sample types indicating that lipid quantitation was more stable across the sample types.

  10. Spatially generalizable representations of facial expressions: Decoding across partial face samples.

    Science.gov (United States)

    Greening, Steven G; Mitchell, Derek G V; Smith, Fraser W

    2018-04-01

    A network of cortical and sub-cortical regions is known to be important in the processing of facial expression. However, to date no study has investigated whether representations of facial expressions present in this network permit generalization across independent samples of face information (e.g., eye region vs mouth region). We presented participants with partial face samples of five expression categories in a rapid event-related fMRI experiment. We reveal a network of face-sensitive regions that contain information about facial expression categories regardless of which part of the face is presented. We further reveal that the neural information present in a subset of these regions: dorsal prefrontal cortex (dPFC), superior temporal sulcus (STS), lateral occipital and ventral temporal cortex, and even early visual cortex, enables reliable generalization across independent visual inputs (faces depicting the 'eyes only' vs 'eyes removed'). Furthermore, classification performance was correlated to behavioral performance in STS and dPFC. Our results demonstrate that both higher (e.g., STS, dPFC) and lower level cortical regions contain information useful for facial expression decoding that go beyond the visual information presented, and implicate a key role for contextual mechanisms such as cortical feedback in facial expression perception under challenging conditions of visual occlusion. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Large scale aggregate microarray analysis reveals three distinct molecular subclasses of human preeclampsia.

    Science.gov (United States)

    Leavey, Katherine; Bainbridge, Shannon A; Cox, Brian J

    2015-01-01

    Preeclampsia (PE) is a life-threatening hypertensive pathology of pregnancy affecting 3-5% of all pregnancies. To date, PE has no cure, early detection markers, or effective treatments short of the removal of what is thought to be the causative organ, the placenta, which may necessitate a preterm delivery. Additionally, numerous small placental microarray studies attempting to identify "PE-specific" genes have yielded inconsistent results. We therefore hypothesize that preeclampsia is a multifactorial disease encompassing several pathology subclasses, and that large cohort placental gene expression analysis will reveal these groups. To address our hypothesis, we utilized known bioinformatic methods to aggregate 7 microarray data sets across multiple platforms in order to generate a large data set of 173 patient samples, including 77 with preeclampsia. Unsupervised clustering of these patient samples revealed three distinct molecular subclasses of PE. This included a "canonical" PE subclass demonstrating elevated expression of known PE markers and genes associated with poor oxygenation and increased secretion, as well as two other subclasses potentially representing a poor maternal response to pregnancy and an immunological presentation of preeclampsia. Our analysis sheds new light on the heterogeneity of PE patients, and offers up additional avenues for future investigation. Hopefully, our subclassification of preeclampsia based on molecular diversity will finally lead to the development of robust diagnostics and patient-based treatments for this disorder.

  12. Off-road sampling reveals a different grassland bird community than roadside sampling: implications for survey design and estimates to guide conservation

    Directory of Open Access Journals (Sweden)

    Troy I. Wellicome

    2014-06-01

    concern. Our results highlight the need to develop appropriate corrections for bias in estimates derived from roadside sampling, and the need to design surveys that sample bird communities across a more representative cross-section of the landscape, both near and far from roads.

  13. Evaluating sampling strategy for DNA barcoding study of coastal and inland halo-tolerant Poaceae and Chenopodiaceae: A case study for increased sample size.

    Science.gov (United States)

    Yao, Peng-Cheng; Gao, Hai-Yan; Wei, Ya-Nan; Zhang, Jian-Hang; Chen, Xiao-Yong; Li, Hong-Qing

    2017-01-01

    Environmental conditions in coastal salt marsh habitats have led to the development of specialist genetic adaptations. We evaluated six DNA barcode loci of the 53 species of Poaceae and 15 species of Chenopodiaceae from China's coastal salt marsh area and inland area. Our results indicate that the optimum DNA barcode was ITS for coastal salt-tolerant Poaceae and matK for the Chenopodiaceae. Sampling strategies for ten common species of Poaceae and Chenopodiaceae were analyzed according to optimum barcode. We found that by increasing the number of samples collected from the coastal salt marsh area on the basis of inland samples, the number of haplotypes of Arundinella hirta, Digitaria ciliaris, Eleusine indica, Imperata cylindrica, Setaria viridis, and Chenopodium glaucum increased, with a principal coordinate plot clearly showing increased distribution points. The results of a Mann-Whitney test showed that for Digitaria ciliaris, Eleusine indica, Imperata cylindrica, and Setaria viridis, the distribution of intraspecific genetic distances was significantly different when samples from the coastal salt marsh area were included (P Imperata cylindrica and Chenopodium album, average intraspecific distance tended to reach stability. These results indicate that the sample size for DNA barcode of globally distributed species should be increased to 11-15.

  14. A preliminary study on identification of Thai rice samples by INAA and statistical analysis

    Science.gov (United States)

    Kongsri, S.; Kukusamude, C.

    2017-09-01

    This study aims to investigate the elemental compositions in 93 Thai rice samples using instrumental neutron activation analysis (INAA) and to identify rice according to their types and rice cultivars using statistical analysis. As, Mg, Cl, Al, Br, Mn, K, Rb and Zn in Thai jasmine rice and Sung Yod rice samples were successfully determined by INAA. The accuracy and precision of the INAA method were verified by SRM 1568a Rice Flour. All elements were found to be in a good agreement with the certified values. The precisions in term of %RSD were lower than 7%. The LODs were obtained in range of 0.01 to 29 mg kg-1. The concentration of 9 elements distributed in Thai rice samples was evaluated and used as chemical indicators to identify the type of rice samples. The result found that Mg, Cl, As, Br, Mn, K, Rb, and Zn concentrations in Thai jasmine rice samples are significantly different but there was no evidence that Al is significantly different from concentration in Sung Yod rice samples at 95% confidence interval. Our results may provide preliminary information for discrimination of rice samples and may be useful database of Thai rice.

  15. Micro-PIXE evaluation of radioactive cesium transfer in contaminated soil samples

    Science.gov (United States)

    Fujishiro, F.; Ishii, K.; Matsuyama, S.; Arai, H.; Ishizaki, A.; Osada, N.; Sugai, H.; Kusano, K.; Nozawa, Y.; Yamauchi, S.; Karahashi, M.; Oshikawa, S.; Kikuchi, K.; Koshio, S.; Watanabe, K.; Suzuki, Y.

    2014-01-01

    Micro-PIXE analysis has been performed on two soil samples with high cesium activity concentrations. These soil samples were contaminated by fallout from the accident at Fukushima Daiichi Nuclear Power Plant. One exhibits a radioactive cesium transfer of ˜0.01, and the other shows a radioactive cesium transfer of less than 0.001, even though both samples have high cesium activity concentrations exceeding 10,000 Bq/kg. X-ray spectra and elemental images of the soil samples revealed the presence of chlorine, which can react with cesium to produce an inorganic soluble compound, and phosphorus-containing cesium-capturable organic compounds.

  16. Imitation and luck: an experimental study on social sampling

    NARCIS (Netherlands)

    Offerman, T.; Schotter, A.

    2007-01-01

    In this paper, we present the results of two experiments on social sampling. In both experiments, people are asked to make a risky decision in a situation where an idiosyncratic luck term a?ects their performance. Before they make their decision, people have the opportunity to sample others who have

  17. Sampled-Data Consensus of Linear Multi-agent Systems With Packet Losses.

    Science.gov (United States)

    Zhang, Wenbing; Tang, Yang; Huang, Tingwen; Kurths, Jurgen

    In this paper, the consensus problem is studied for a class of multi-agent systems with sampled data and packet losses, where random and deterministic packet losses are considered, respectively. For random packet losses, a Bernoulli-distributed white sequence is used to describe packet dropouts among agents in a stochastic way. For deterministic packet losses, a switched system with stable and unstable subsystems is employed to model packet dropouts in a deterministic way. The purpose of this paper is to derive consensus criteria, such that linear multi-agent systems with sampled-data and packet losses can reach consensus. By means of the Lyapunov function approach and the decomposition method, the design problem of a distributed controller is solved in terms of convex optimization. The interplay among the allowable bound of the sampling interval, the probability of random packet losses, and the rate of deterministic packet losses are explicitly derived to characterize consensus conditions. The obtained criteria are closely related to the maximum eigenvalue of the Laplacian matrix versus the second minimum eigenvalue of the Laplacian matrix, which reveals the intrinsic effect of communication topologies on consensus performance. Finally, simulations are given to show the effectiveness of the proposed results.In this paper, the consensus problem is studied for a class of multi-agent systems with sampled data and packet losses, where random and deterministic packet losses are considered, respectively. For random packet losses, a Bernoulli-distributed white sequence is used to describe packet dropouts among agents in a stochastic way. For deterministic packet losses, a switched system with stable and unstable subsystems is employed to model packet dropouts in a deterministic way. The purpose of this paper is to derive consensus criteria, such that linear multi-agent systems with sampled-data and packet losses can reach consensus. By means of the Lyapunov function

  18. Psychometric properties of the Thought-Action Fusion Scale in a Turkish sample.

    Science.gov (United States)

    Yorulmaz, Orçun; Yilmaz, A Esin; Gençöz, Tülin

    2004-10-01

    The aim of the present study was to reveal the cross-cultural utility of the Thought-Action Fusion Scale (TAFS; J. Anxiety Disord. 10 (1996) 379). Thought-action fusion (TAF) refers to the tendency to overvalue the significance and the consequences of thoughts. Two hundred and fifty one undergraduate Turkish students participated in the current study. The reliability and validity analyses of the Turkish version of the scale indicated that the TAFS had adequate psychometric properties in a Turkish sample. Consistent with the original TAF, the Turkish version of TAFS revealed two subscales as TAF-Likelihood and TAF-Morality. Reliability analysis showed that TAF Scale and its factors had adequate internal consistencies and split-half reliability coefficients. Confirming the expectations, TAFS scores were found to be significantly and positively correlated with obsessive-compulsive symptoms, responsibility, and guilt measures. Moreover, it was found that people with high obsessive-compulsive symptoms had higher TAFS scores than those with low symptoms.

  19. Experimental study on the particles deposition in the sampling duct

    Energy Technology Data Exchange (ETDEWEB)

    Vendel, J.; Charuau, J. [Institut de Protection et de Surete Nucleaire, Yvette (France)

    1995-02-01

    A high standard of protection against the harmful effects of radioactive aerosol dissemination requires a measurement, as representative as possible, of their concentration. This measurement depends on the techniques used for aerosol sampling and transfer to the detector, as well as on the location of the latter with respect to the potential sources. The aeraulic design of the apparatus is also an important factor. Once collected the aerosol particles often have to travel through a variably shaped duct to the measurement apparatus. This transport is responsible for losses due to the particles deposition on the walls, leading to a distortion on the concentration measurements and a change in the particle size distribution. To estimate and minimize measurement errors it is important to determine the optimal transport conditions when designing a duct; its diameter and material, the radius of curvature of the bends and the flow conditions must be defined in particular. This paper presents an experimental study in order to determine, for each deposition mechanism, the retained fraction, or the deposition velocity for different flow regimes. This study has pointed out that it exists a favourable flow regime for the particle transport through the sampling ducts (2 500 < Re < 5 000). It has been established, for any particle diameters, equations to predict the aerosol penetration in smooth-walled cylindrical metal ducts.

  20. Gaussian graphical modeling reveals specific lipid correlations in glioblastoma cells

    Science.gov (United States)

    Mueller, Nikola S.; Krumsiek, Jan; Theis, Fabian J.; Böhm, Christian; Meyer-Bäse, Anke

    2011-06-01

    Advances in high-throughput measurements of biological specimens necessitate the development of biologically driven computational techniques. To understand the molecular level of many human diseases, such as cancer, lipid quantifications have been shown to offer an excellent opportunity to reveal disease-specific regulations. The data analysis of the cell lipidome, however, remains a challenging task and cannot be accomplished solely based on intuitive reasoning. We have developed a method to identify a lipid correlation network which is entirely disease-specific. A powerful method to correlate experimentally measured lipid levels across the various samples is a Gaussian Graphical Model (GGM), which is based on partial correlation coefficients. In contrast to regular Pearson correlations, partial correlations aim to identify only direct correlations while eliminating indirect associations. Conventional GGM calculations on the entire dataset can, however, not provide information on whether a correlation is truly disease-specific with respect to the disease samples and not a correlation of control samples. Thus, we implemented a novel differential GGM approach unraveling only the disease-specific correlations, and applied it to the lipidome of immortal Glioblastoma tumor cells. A large set of lipid species were measured by mass spectrometry in order to evaluate lipid remodeling as a result to a combination of perturbation of cells inducing programmed cell death, while the other perturbations served solely as biological controls. With the differential GGM, we were able to reveal Glioblastoma-specific lipid correlations to advance biomedical research on novel gene therapies.

  1. Microwave-assisted headspace single-drop microextration of chlorobenzenes from water samples

    Energy Technology Data Exchange (ETDEWEB)

    Vidal, Lorena [Departamento de Quimica Analitica, Nutricion y Bromatologia, Universidad de Alicante, P.O. Box 99, E-03080 Alicante (Spain); Domini, Claudia E. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Universidad de Alicante, P.O. Box 99, E-03080 Alicante (Spain); Grane, Nuria [Departamento de Quimica Analitica, Nutricion y Bromatologia, Universidad de Alicante, P.O. Box 99, E-03080 Alicante (Spain); Psillakis, Elefteria [Department of Environmental Engineering, Technical University of Crete, Polytechneioupolis, GR-73100 Chania, Crete (Greece); Canals, Antonio [Departamento de Quimica Analitica, Nutricion y Bromatologia, Universidad de Alicante, P.O. Box 99, E-03080 Alicante (Spain)]. E-mail: a.canals@ua.es

    2007-05-29

    A one-step and in-situ sample preparation method used for quantifying chlorobenzene compounds in water samples has been developed, coupling microwave and headspace single-drop microextraction (MW-HS-SDME). The chlorobenzenes in water samples were extracted directly onto an ionic liquid single-drop in headspace mode under the aid of microwave radiation. For optimization, a Plackett-Burman screening design was initially used, followed by a mixed-level factorial design. The factors considered were: drop volume, aqueous sample volume, stirring speed, ionic strength, extraction time, ionic liquid type, microwave power and length of the Y-shaped glass-tube. The optimum experimental conditions found from this statistical evaluation were: a 5 {mu}L microdrop of 1-hexyl-3-methylimidazolium hexafluorophosphate exposed for 20 min to the headspace of a 30 mL aqueous sample, irradiated by microwaves at 200 W and placed in a 50 mL spherical flask connected to a 25 cm Y-shaped glass-tube. Under the optimised experimental conditions, the response of a high performance liquid chromatographic system was found to be linear over the range studied and with correlation coefficients ranging between 0.9995 and 0.9999. The method showed a good level of repeatability, with relative standard deviations varying between 2.3 and 8.3% (n = 5). Detection limits were found in the low {mu}g L{sup -1} range varying between 0.016 and 0.039 {mu}g L{sup -1}. Overall, the performance of the proposed method demonstrated the favourable effect of microwave sample irradiation upon HS-SDME. Finally, recovery studies from different types of environmental water samples revealed that matrix had little effect upon extraction.

  2. Microwave-assisted headspace single-drop microextration of chlorobenzenes from water samples

    International Nuclear Information System (INIS)

    Vidal, Lorena; Domini, Claudia E.; Grane, Nuria; Psillakis, Elefteria; Canals, Antonio

    2007-01-01

    A one-step and in-situ sample preparation method used for quantifying chlorobenzene compounds in water samples has been developed, coupling microwave and headspace single-drop microextraction (MW-HS-SDME). The chlorobenzenes in water samples were extracted directly onto an ionic liquid single-drop in headspace mode under the aid of microwave radiation. For optimization, a Plackett-Burman screening design was initially used, followed by a mixed-level factorial design. The factors considered were: drop volume, aqueous sample volume, stirring speed, ionic strength, extraction time, ionic liquid type, microwave power and length of the Y-shaped glass-tube. The optimum experimental conditions found from this statistical evaluation were: a 5 μL microdrop of 1-hexyl-3-methylimidazolium hexafluorophosphate exposed for 20 min to the headspace of a 30 mL aqueous sample, irradiated by microwaves at 200 W and placed in a 50 mL spherical flask connected to a 25 cm Y-shaped glass-tube. Under the optimised experimental conditions, the response of a high performance liquid chromatographic system was found to be linear over the range studied and with correlation coefficients ranging between 0.9995 and 0.9999. The method showed a good level of repeatability, with relative standard deviations varying between 2.3 and 8.3% (n = 5). Detection limits were found in the low μg L -1 range varying between 0.016 and 0.039 μg L -1 . Overall, the performance of the proposed method demonstrated the favourable effect of microwave sample irradiation upon HS-SDME. Finally, recovery studies from different types of environmental water samples revealed that matrix had little effect upon extraction

  3. Imitation and luck: an experimental study on social sampling

    NARCIS (Netherlands)

    Offerman, T.; Schotter, A.

    2008-01-01

    In this paper, we present the results of two experiments on social sampling, where people make a risky decision after they have sampled the behavior of others who have done exactly the same problem before them. In an individual decision making problem as well as in the take-over game, the simple

  4. Automated sample preparation station for studying self-diffusion in porous solids with NMR spectroscopy

    Science.gov (United States)

    Hedin, Niklas; DeMartin, Gregory J.; Reyes, Sebastián C.

    2006-03-01

    In studies of gas diffusion in porous solids with nuclear magnetic resonance (NMR) spectroscopy the sample preparation procedure becomes very important. An apparatus is presented here that pretreats the sample ex situ and accurately sets the desired pressure and temperature within the NMR tube prior to its introduction in the spectrometer. The gas manifold that supplies the NMR tube is also connected to a microbalance containing another portion of the same sample, which is kept at the same temperature as the sample in the NMR tube. This arrangement permits the simultaneous measurement of the adsorption loading on the sample, which is required for the interpretation of the NMR diffusion experiments. Furthermore, to ensure a good seal of the NMR tube, a hybrid valve design composed of titanium, a Teflon® seat, and Kalrez® O-rings is utilized. A computer controlled algorithm ensures the accuracy and reproducibility of all the procedures, enabling the NMR diffusion experiments to be performed at well controlled conditions of pressure, temperature, and amount of gas adsorbed on the porous sample.

  5. Water quality monitoring: A comparative case study of municipal and Curtin Sarawak's lake samples

    Science.gov (United States)

    Anand Kumar, A.; Jaison, J.; Prabakaran, K.; Nagarajan, R.; Chan, Y. S.

    2016-03-01

    In this study, particle size distribution and zeta potential of the suspended particles in municipal water and lake surface water of Curtin Sarawak's lake were compared and the samples were analysed using dynamic light scattering method. High concentration of suspended particles affects the water quality as well as suppresses the aquatic photosynthetic systems. A new approach has been carried out in the current work to determine the particle size distribution and zeta potential of the suspended particles present in the water samples. The results for the lake samples showed that the particle size ranges from 180nm to 1345nm and the zeta potential values ranges from -8.58 mV to -26.1 mV. High zeta potential value was observed in the surface water samples of Curtin Sarawak's lake compared to the municipal water. The zeta potential values represent that the suspended particles are stable and chances of agglomeration is lower in lake water samples. Moreover, the effects of physico-chemical parameters on zeta potential of the water samples were also discussed.

  6. Study of lead pollution in air, soil and water samples of Quetta city

    International Nuclear Information System (INIS)

    Khan, M.; Khan, G.M.; Akbar, S.; Panezai, M.A.; Haq, Z.U.

    2011-01-01

    This study briefly presents the collected data of lead pollution in the environment of Quetta City in Balochistan, Pakistan. The samples were collected from different sites. The analysis of lead was carried out in underground water samples, the exhaust of different vehicles, roadside and sewage soils from selected points of Quetta City. The average discharge resulted in deposition by motorcycles (29.12 g/h), cars (44.47 g/h), wagons (176.54 g/h) and buses (141.52 g/h). The maximum deposition was 222.96 g/h from auto-rickshaws. The value for lead in smoke of different vehicles seems quite high when extrapolated to the large number of such vehicles for a longer time. The concentration of lead in roadside soil varied from 73.3 mg/kg (T and T closed colony) to 731.9 mg/kg (Sirki road bus-stop). The average content of lead in sewage soil of City Nala is 1250.6 mg/kg. The level of lead was more than WHO standards for such soils. The lead quantity in all 24 tube- well water samples, was slightly above the WHO standards (10 macro g/L).The results of this study were comparable to similar study in twin cities of Rawalpindi and islamabad. (author)

  7. A large study reveals no Association between APOE and Parkinson’s disease

    Science.gov (United States)

    Federoff, Monica; Jimenez-Rolando, Belen; Nalls, Michael A; Singleton, Andrew B

    2012-01-01

    Background Research focusing on the role of APOE in Parkinson’s disease (PD) has been largely inconclusive, creating a broad discrepancy in association studies. Objective To elucidate the role of APOE alleles in PD risk by studying a large sample size and controlling for population substructure. Patients and Methods In total, 3465 case and control samples were genotyped, obtained from the NINDS Neurogenetics repository. Results No significant differences in ε4 dosages exist between PD cases and controls. The frequency of ε4 carriers differed slightly between cases and controls at 24% (580/2412) and 26% (270/1053), respectively. Likewise, mean dosages of APOE ε2 were not significantly different between cases and controls. APOE ε2 carriers were observed at a frequency of 13.6% (329/2412) among cases and 15% (158/1053) among controls. Logistic regression models evaluating PD as possibly associated with ε4 or ε2 carrier status and allele dosages yielded no significant results. The mean MMSE score among all PD cases was 28.35 (SD = 2.58) and memory loss was reported in only 11.9% (105/879) of cases. Linear regression models comparing MMSE scores as predicted by ε4 or ε2 carrier status and allele dosages were not significant. Conclusions There is no association between APOE epsilon alleles and Parkinson’s disease. PMID:22349451

  8. PCR-Based Analysis of ColE1 Plasmids in Clinical Isolates and Metagenomic Samples Reveals Their Importance as Gene Capture Platforms

    Directory of Open Access Journals (Sweden)

    Manuel Ares-Arroyo

    2018-03-01

    Full Text Available ColE1 plasmids are important vehicles for the spread of antibiotic resistance in the Enterobacteriaceae and Pasteurellaceae families of bacteria. Their monitoring is essential, as they harbor important resistant determinants in humans, animals and the environment. In this work, we have analyzed ColE1 replicons using bioinformatic and experimental approaches. First, we carried out a computational study examining the structure of different ColE1 plasmids deposited in databases. Bioinformatic analysis of these ColE1 replicons revealed a mosaic genetic structure consisting of a host-adapted conserved region responsible for the housekeeping functions of the plasmid, and a variable region encoding a wide variety of genes, including multiple antibiotic resistance determinants. From this exhaustive computational analysis we developed a new PCR-based technique, targeting a specific sequence in the conserved region, for the screening, capture and sequencing of these small plasmids, either specific for Enterobacteriaceae or specific for Pasteurellaceae. To validate this PCR-based system, we tested various collections of isolates from both bacterial families, finding that ColE1 replicons were not only highly prevalent in antibiotic-resistant isolates, but also present in susceptible bacteria. In Pasteurellaceae, ColE1 plasmids carried almost exclusively antibiotic resistance genes. In Enterobacteriaceae, these plasmids encoded a large range of traits, including not only antibiotic resistance determinants, but also a wide variety of genes, showing the huge genetic plasticity of these small replicons. Finally, we also used a metagenomic approach in order to validate this technique, performing this PCR system using total DNA extractions from fecal samples from poultry, turkeys, pigs and humans. Using Illumina sequencing of the PCR products we identified a great diversity of genes encoded by ColE1 replicons, including different antibiotic resistance

  9. Excess fertilizer responsive miRNAs revealed in Linum usitatissimum L.

    Science.gov (United States)

    Melnikova, Nataliya V; Dmitriev, Alexey A; Belenikin, Maxim S; Speranskaya, Anna S; Krinitsina, Anastasia A; Rachinskaia, Olga A; Lakunina, Valentina A; Krasnov, George S; Snezhkina, Anastasiya V; Sadritdinova, Asiya F; Uroshlev, Leonid A; Koroban, Nadezda V; Samatadze, Tatiana E; Amosova, Alexandra V; Zelenin, Alexander V; Muravenko, Olga V; Bolsheva, Nadezhda L; Kudryavtseva, Anna V

    2015-02-01

    Effective fertilizer application is necessary to increase crop yields and reduce risk of plant overdosing. It is known that expression level of microRNAs (miRNAs) alters in plants under different nutrient concentrations in soil. The aim of our study was to identify and characterize miRNAs with expression alterations under excessive fertilizer in agriculturally important crop - flax (Linum usitatissimum L.). We have sequenced small RNAs in flax grown under normal and excessive fertilizer using Illumina GAIIx. Over 14 million raw reads was obtained for two small RNA libraries. 84 conserved miRNAs from 20 families were identified. Differential expression was revealed for several flax miRNAs under excessive fertilizer according to high-throughput sequencing data. For 6 miRNA families (miR395, miR169, miR408, miR399, miR398 and miR168) expression level alterations were evaluated on the extended sampling using qPCR. Statistically significant up-regulation was revealed for miR395 under excessive fertilizer. It is known that target genes of miR395 are involved in sulfate uptake and assimilation. However, according to our data alterations of the expression level of miR395 could be associated not only with excess sulfur application, but also with redundancy of other macro- and micronutrients. Furthermore expression level was evaluated for miRNAs and their predicted targets. The negative correlation between miR399 expression and expression of its predicted target ubiquitin-conjugating enzyme E2 gene was shown in flax for the first time. So we suggested miR399 involvement in phosphate regulation in L. usitatissimum. Revealed in our study expression alterations contribute to miRNA role in flax response to excessive fertilizer. Copyright © 2014 Elsevier B.V. and Société française de biochimie et biologie Moléculaire (SFBBM). All rights reserved.

  10. Soil sampling

    International Nuclear Information System (INIS)

    Fortunati, G.U.; Banfi, C.; Pasturenzi, M.

    1994-01-01

    This study attempts to survey the problems associated with techniques and strategies of soil sampling. Keeping in mind the well defined objectives of a sampling campaign, the aim was to highlight the most important aspect of representativeness of samples as a function of the available resources. Particular emphasis was given to the techniques and particularly to a description of the many types of samplers which are in use. The procedures and techniques employed during the investigations following the Seveso accident are described. (orig.)

  11. A study of diabetes mellitus within a large sample of Australian twins

    DEFF Research Database (Denmark)

    Condon, Julianne; Shaw, Joanne E; Luciano, Michelle

    2008-01-01

    with type 2 diabetes (T2D), 41 female pairs with gestational diabetes (GD), 5 pairs with impaired glucose tolerance (IGT) and one pair with MODY. Heritabilities of T1D, T2D and GD were all high, but our samples did not have the power to detect effects of shared environment unless they were very large......Twin studies of diabetes mellitus can help elucidate genetic and environmental factors in etiology and can provide valuable biological samples for testing functional hypotheses, for example using expression and methylation studies of discordant pairs. We searched the volunteer Australian Twin...... Registry (19,387 pairs) for twins with diabetes using disease checklists from nine different surveys conducted from 1980-2000. After follow-up questionnaires to the twins and their doctors to confirm diagnoses, we eventually identified 46 pairs where one or both had type 1 diabetes (T1D), 113 pairs...

  12. Educational data mining: a sample of review and study case

    Directory of Open Access Journals (Sweden)

    Alejandro Pena, Rafael Domínguez, Jose de Jesus Medel

    2009-12-01

    Full Text Available The aim of this work is to encourage the research in a novel merged field: Educational data mining (EDM. Thereby, twosubjects are outlined: The first one corresponds to a review of data mining (DM methods and EDM applications. Thesecond topic represents an EDM study case. As a result of the application of DM in Web-based Education Systems (WBES,stratified groups of students were found during a trial. Such groups reveal key attributes of volunteers that deserted orremained during a WBES experiment. This kind of discovered knowledge inspires the statement of correlational hypothesisto set relations between attributes and behavioral patterns of WBES users. We concluded that: When EDM findings aretaken into account for designing and managing WBES, the learning objectives are improved

  13. Using Dried Blood Spot Sampling to Improve Data Quality and Reduce Animal Use in Mouse Pharmacokinetic Studies

    Science.gov (United States)

    Wickremsinhe, Enaksha R; Perkins, Everett J

    2015-01-01

    Traditional pharmacokinetic analysis in nonclinical studies is based on the concentration of a test compound in plasma and requires approximately 100 to 200 µL blood collected per time point. However, the total blood volume of mice limits the number of samples that can be collected from an individual animal—often to a single collection per mouse—thus necessitating dosing multiple mice to generate a pharmacokinetic profile in a sparse-sampling design. Compared with traditional methods, dried blood spot (DBS) analysis requires smaller volumes of blood (15 to 20 µL), thus supporting serial blood sampling and the generation of a complete pharmacokinetic profile from a single mouse. Here we compare plasma-derived data with DBS-derived data, explain how to adopt DBS sampling to support discovery mouse studies, and describe how to generate pharmacokinetic and pharmacodynamic data from a single mouse. Executing novel study designs that use DBS enhances the ability to identify and streamline better drug candidates during drug discovery. Implementing DBS sampling can reduce the number of mice needed in a drug discovery program. In addition, the simplicity of DBS sampling and the smaller numbers of mice needed translate to decreased study costs. Overall, DBS sampling is consistent with 3Rs principles by achieving reductions in the number of animals used, decreased restraint-associated stress, improved data quality, direct comparison of interanimal variability, and the generation of multiple endpoints from a single study. PMID:25836959

  14. Patterns of traffic polycyclic aromatic hydrocarbon pollution in mountain areas can be revealed by lichen biomonitoring: a case study in the Dolomites (Eastern Italian Alps).

    Science.gov (United States)

    Nascimbene, Juri; Tretiach, Mauro; Corana, Federica; Lo Schiavo, Fiorella; Kodnik, Danijela; Dainese, Matteo; Mannucci, Barbara

    2014-03-15

    In mountain areas of touristic interest the evaluation of the impact of human activities is crucial for ensuring long-term conservation of ecosystem biodiversity, functions and services. This study aimed at verifying the biological impact of polycyclic aromatic hydrocarbon (PAH) emissions due to traffic along the roads leading to seven passes of the Dolomites (SE Alps), which were recently declared a UNESCO World Heritage Site. Thalli of the epiphytic lichen Pseudevernia furfuracea, collected at increasing distances from the roads, were used as biomonitors. Our study revealed a gradient of decreasing PAH pollution within 300 m from the roads. Differences among passes were evident mainly for samples collected nearest to the roads, but PAH concentrations at 300 m were almost always higher than those of undisturbed reference sites, indicating that traffic PAH pollution may impact natural ecosystems and lichen diversity at relatively long distances from the emission source. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. A topological analysis of large-scale structure, studied using the CMASS sample of SDSS-III

    International Nuclear Information System (INIS)

    Parihar, Prachi; Gott, J. Richard III; Vogeley, Michael S.; Choi, Yun-Young; Kim, Juhan; Kim, Sungsoo S.; Speare, Robert; Brownstein, Joel R.; Brinkmann, J.

    2014-01-01

    We study the three-dimensional genus topology of large-scale structure using the northern region of the CMASS Data Release 10 (DR10) sample of the SDSS-III Baryon Oscillation Spectroscopic Survey. We select galaxies with redshift 0.452 < z < 0.625 and with a stellar mass M stellar > 10 11.56 M ☉ . We study the topology at two smoothing lengths: R G = 21 h –1 Mpc and R G = 34 h –1 Mpc. The genus topology studied at the R G = 21 h –1 Mpc scale results in the highest genus amplitude observed to date. The CMASS sample yields a genus curve that is characteristic of one produced by Gaussian random phase initial conditions. The data thus support the standard model of inflation where random quantum fluctuations in the early universe produced Gaussian random phase initial conditions. Modest deviations in the observed genus from random phase are as expected from shot noise effects and the nonlinear evolution of structure. We suggest the use of a fitting formula motivated by perturbation theory to characterize the shift and asymmetries in the observed genus curve with a single parameter. We construct 54 mock SDSS CMASS surveys along the past light cone from the Horizon Run 3 (HR3) N-body simulations, where gravitationally bound dark matter subhalos are identified as the sites of galaxy formation. We study the genus topology of the HR3 mock surveys with the same geometry and sampling density as the observational sample and find the observed genus topology to be consistent with ΛCDM as simulated by the HR3 mock samples. We conclude that the topology of the large-scale structure in the SDSS CMASS sample is consistent with cosmological models having primordial Gaussian density fluctuations growing in accordance with general relativity to form galaxies in massive dark matter halos.

  16. Effects of sterilization treatments on the analysis of TOC in water samples.

    Science.gov (United States)

    Shi, Yiming; Xu, Lingfeng; Gong, Dongqin; Lu, Jun

    2010-01-01

    Decomposition experiments conducted with and without microbial processes are commonly used to study the effects of environmental microorganisms on the degradation of organic pollutants. However, the effects of biological pretreatment (sterilization) on organic matter often have a negative impact on such experiments. Based on the principle of water total organic carbon (TOC) analysis, the effects of physical sterilization treatments on determination of TOC and other water quality parameters were investigated. The results revealed that two conventional physical sterilization treatments, autoclaving and 60Co gamma-radiation sterilization, led to the direct decomposition of some organic pollutants, resulting in remarkable errors in the analysis of TOC in water samples. Furthermore, the extent of the errors varied with the intensity and the duration of sterilization treatments. Accordingly, a novel sterilization method for water samples, 0.45 microm micro-filtration coupled with ultraviolet radiation (MCUR), was developed in the present study. The results indicated that the MCUR method was capable of exerting a high bactericidal effect on the water sample while significantly decreasing the negative impact on the analysis of TOC and other water quality parameters. Before and after sterilization treatments, the relative errors of TOC determination could be controlled to lower than 3% for water samples with different categories and concentrations of organic pollutants by using MCUR.

  17. Fingerprinting analysis of oil samples for inter-laboratory Round Robin, 2007

    Energy Technology Data Exchange (ETDEWEB)

    Yang, C.; Wang, Z.; Hollebone, B.; Brown, C.E.; Landriault, M. [Environment Canada, Ottawa, ON (Canada). Emergencies Science and Technology Division, Science and Technology Branch, Environmental Science and Technology Centre; Shang, D. [Environment Canada, North Vancouver, BC (Canada). Pacific Environmental Science Centre; Losier, R.; Cook, A. [Environment Canada, Moncton, NB (Canada). Environmental Science Centre

    2008-07-01

    The oil from an oil spill must undergo a complete chemical characterization in order to determine the source of the oil, to distinguish the spilled oil from background hydrocarbons and to evaluate the extent of impact. A study was conducted to determine the ability of international analytical laboratories to independently conduct forensic oil analysis and identification. A Round Robin study was conducted in which advanced chemical fingerprinting and data interpretation techniques were used to differentiate the types and sources of spilled oils. The participants of the Round Robin exercise were the Institute of Inland Water Management and Waste Water Treatment (RIZA) in the Netherlands and the Federal Maritime and Hydrographic Agency (BSH) in Germany. In May 2007, 6 oil samples were distributed to the participants. In the artificial oil spill scenario, 2 oil samples were considered as candidate sources and the other 4 samples were labeled as spilled oils. No other information about these oils was provided before submission of final results. Chemical fingerprinting was carried out using gas chromatography, flame ionization detection and mass spectrometry along with statistical data to determine the source of the spill. N-alkanes, alkylated polyaromatic hydrocarbons, biomarker terpanes and steranes and triaromatic steranes were normalized to C{sub 30} 17{alpha}(H)21{beta}(H)-hopane and then semi-quantitated. Thirty diagnostic ratios of target compounds were calculated from their peak heights and areas at selected ions. Results of the 2 source samples were compared with 4 spill samples. Tiered fingerprinting analysis revealed that source oil 1 was a non-match with spill samples 3 and 4, but a probable match with spill samples 5 and 6. Source sample 2 did not match any of the 4 spilled oils. A lack of background information essential to oil spill identification made it impossible to draw an unambiguous conclusion. 14 refs., 4 tabs., 6 figs.

  18. Fingerprinting analysis of oil samples for inter-laboratory Round Robin, 2007

    International Nuclear Information System (INIS)

    Yang, C.; Wang, Z.; Hollebone, B.; Brown, C.E.; Landriault, M.; Shang, D.; Losier, R.; Cook, A.

    2008-01-01

    The oil from an oil spill must undergo a complete chemical characterization in order to determine the source of the oil, to distinguish the spilled oil from background hydrocarbons and to evaluate the extent of impact. A study was conducted to determine the ability of international analytical laboratories to independently conduct forensic oil analysis and identification. A Round Robin study was conducted in which advanced chemical fingerprinting and data interpretation techniques were used to differentiate the types and sources of spilled oils. The participants of the Round Robin exercise were the Institute of Inland Water Management and Waste Water Treatment (RIZA) in the Netherlands and the Federal Maritime and Hydrographic Agency (BSH) in Germany. In May 2007, 6 oil samples were distributed to the participants. In the artificial oil spill scenario, 2 oil samples were considered as candidate sources and the other 4 samples were labeled as spilled oils. No other information about these oils was provided before submission of final results. Chemical fingerprinting was carried out using gas chromatography, flame ionization detection and mass spectrometry along with statistical data to determine the source of the spill. N-alkanes, alkylated polyaromatic hydrocarbons, biomarker terpanes and steranes and triaromatic steranes were normalized to C 30 17α(H)21β(H)-hopane and then semi-quantitated. Thirty diagnostic ratios of target compounds were calculated from their peak heights and areas at selected ions. Results of the 2 source samples were compared with 4 spill samples. Tiered fingerprinting analysis revealed that source oil 1 was a non-match with spill samples 3 and 4, but a probable match with spill samples 5 and 6. Source sample 2 did not match any of the 4 spilled oils. A lack of background information essential to oil spill identification made it impossible to draw an unambiguous conclusion. 14 refs., 4 tabs., 6 figs

  19. Self-sampling for human papillomavirus DNA detection: a preliminary study of compliance and feasibility in BOLIVIA.

    Science.gov (United States)

    Surriabre, Pedro; Allende, Gustavo; Prado, Marcela; Cáceres, Leyddy; Bellot, Diego; Torrico, Andrea; Ustariz, Karina; Rojas, Shirley; Barriga, Jaime; Calle, Pamela; Villarroel, Ligia; Yañez, Rosse Mary; Baay, Marc; Rodriguez, Patricia; Fontaine, Véronique

    2017-12-22

    Cervical cancer incidence and mortality rates in Bolivia are among the highest in Latin America. This investigation aims to evaluate the possibility of using simple devices, e.g. a cotton swab and a glass slide, for self-sampling in order to detect human papillomavirus (HPV) DNA by PCR in cervico-vaginal cells. In the first phase of our study we evaluated the use of a glass slide as a transport medium for cervical cells. A physician took paired-cervical samples from 235 women. One sample was transported in Easyfix® solution and the other sample was smeared over a glass slide. Both were further analyzed and compared for human DNA recovery and HPV detection. A kappa value was determined to evaluate the agreement between the HPV DNA detection rates. In the second phase of the study, 222 women from the urban, peri-urban and rural regions of Cochabamba were requested to perform self-sampling using the following devices: a cotton swab combined with a glass slide, and a vaginal tampon. Women gave their opinion about the self-sampling technique. Finally, the agreement for high risk-HPV detection between self- and physician-collected samples was performed in 201 samples in order to evaluate the self-sampling technique. Firstly, the comparison between Easyfix® solution and the glass slide to transport clinical samples gave a good agreement for HPV DNA detection (κ = 0.71, 95% CI 0.60-0.81). Secondly, self-sampling, especially with cotton swab combined with glass slide, would generally be preferred over clinician sampling for a screening program based on HPV detection. Finally, we showed a good agreement between self- and physician collected samples for high risk-HPV detection (κ = 0.71, 95% CI 0.55-0.88). Simple devices such as a cotton swab and a glass slide can be used to perform self-sampling and HPV DNA detection. Furthermore, most Bolivian women preferred self-sampling over clinician-sampling for cervical cancer screening.

  20. Human papilloma virus 18 detection in oral squamous cell carcinoma and potentially malignant lesions using saliva samples.

    Science.gov (United States)

    Goot-Heah, Khor; Kwai-Lin, Thong; Froemming, Gabriele Ruth Anisah; Abraham, Mannil Thomas; Nik Mohd Rosdy, Nik Mohd Mazuan; Zain, Rosnah Binti

    2012-01-01

    Oral cancer has become one of the most prevalent cancers worldwide and human Papillomavirus is one of the risk factors for developing oral cancer. For this study HPV18 was chosen as it is one of the high risk HPV types and may lead to carcinogenesis. However, prevalence of HPV18 infection in Oral Squamous Cell Carcinoma in Malaysia remains unclear. This study aimed to investigate the viral load of HPV18 DNA in OSCC and potentially malignant lesions using saliva samples. Genomic DNAs of thirty saliva samples of normal subjects and thirty saliva samples compromised of 16 samples from potentially malignant lesions and 14 of OSCC patients were amplified for HPV18 DNA using a nested polymerase chain reaction analysis. All PCR products were then analyzed using the Bioanalyzer to confirm presence of HPV18 DNA. From thirty patients examined, only one of 30 (3.3%) cases was found to be positive for HPV18 in this study. The finding of this study revealed that there is a low viral detection of HPV18 in Malaysian OSCC by using saliva samples, suggesting that prevalence of HPV18 may not be important in this group of Malaysian OSCC.

  1. Risk assessment due to ingestion of natural radionuclides and heavy metals in the milk samples: a case study from a proposed uranium mining area, Jharkhand.

    Science.gov (United States)

    Giri, Soma; Singh, Gurdeep; Jha, V N; Tripathi, R M

    2011-04-01

    Ingestion of radionuclides and heavy metals through drinking water and food intake represents one of the important pathways for long-term health considerations. Milk and milk products are main constituents of the daily diet. Radionuclides and heavy metals can be apprehended in the ecosystem of the East Singhbhum region which is known for its viable grades of uranium, copper and other minerals. For the risk assessment studies, samples of milk were collected from twelve villages around Bagjata mining area and analysed for U(nat), 226Ra, 230Th, 210Po, Fe, Mn, Zn, Pb, Cu and Ni. Analysis of the results of the study reveals that the geometric mean of U(nat), 226Ra, 230Th and 210Po was 0.021, 0.24, 0.23 and 1.08 Bq l(-1), respectively. The ingestion dose was calculated to be 12.34 μSvY(-1) which is reflecting the natural background dose via the route of ingestion, and much below the 1 mSv limit set in the new ICRP recommendations. The excess lifetime cancer risk was estimated to be 1.72×10(-4) which is within the acceptable excess individual lifetime cancer risk value of 1×10(-4). The geometric mean of Fe, Mn, Zn, Cu and Ni was 4.91, 0.29, 4.77, 0.56 and 0.48 mgl(-1), respectively; whereas the daily intake was computed to be 0.44, 0.03, 0.43, 0.05 and 0.04 mg/day, respectively. Pb was not detected in any of the samples. The hazard quotient revealed that the intake of the heavy metals through the ingestion of milk does not pose any apparent threat to the local people as none of the HQ of the heavy metals exceeds the limit of 1.

  2. Gender differences in the structural connectome of the teenage brain revealed by generalized q-sampling MRI

    Directory of Open Access Journals (Sweden)

    Yeu-Sheng Tyan

    2017-01-01

    Full Text Available The question of whether there are biological differences between male and female brains is a fraught one, and political positions and prior expectations seem to have a strong influence on the interpretation of scientific data in this field. This question is relevant to issues of gender differences in the prevalence of psychiatric conditions, including autism, attention deficit hyperactivity disorder (ADHD, Tourette's syndrome, schizophrenia, dyslexia, depression, and eating disorders. Understanding how gender influences vulnerability to these conditions is significant. Diffusion magnetic resonance imaging (dMRI provides a non-invasive method to investigate brain microstructure and the integrity of anatomical connectivity. Generalized q-sampling imaging (GQI has been proposed to characterize complicated fiber patterns and distinguish fiber orientations, providing an opportunity for more accurate, higher-order descriptions through the water diffusion process. Therefore, we aimed to investigate differences in the brain's structural network between teenage males and females using GQI. This study included 59 (i.e., 33 males and 26 females age- and education-matched subjects (age range: 13 to 14 years. The structural connectome was obtained by graph theoretical and network-based statistical (NBS analyses. Our findings show that teenage male brains exhibit better intrahemispheric communication, and teenage female brains exhibit better interhemispheric communication. Our results also suggest that the network organization of teenage male brains is more local, more segregated, and more similar to small-world networks than teenage female brains. We conclude that the use of an MRI study with a GQI-based structural connectomic approach like ours presents novel insights into network-based systems of the brain and provides a new piece of the puzzle regarding gender differences.

  3. Gender differences in the structural connectome of the teenage brain revealed by generalized q-sampling MRI.

    Science.gov (United States)

    Tyan, Yeu-Sheng; Liao, Jan-Ray; Shen, Chao-Yu; Lin, Yu-Chieh; Weng, Jun-Cheng

    2017-01-01

    The question of whether there are biological differences between male and female brains is a fraught one, and political positions and prior expectations seem to have a strong influence on the interpretation of scientific data in this field. This question is relevant to issues of gender differences in the prevalence of psychiatric conditions, including autism, attention deficit hyperactivity disorder (ADHD), Tourette's syndrome, schizophrenia, dyslexia, depression, and eating disorders. Understanding how gender influences vulnerability to these conditions is significant. Diffusion magnetic resonance imaging (dMRI) provides a non-invasive method to investigate brain microstructure and the integrity of anatomical connectivity. Generalized q-sampling imaging (GQI) has been proposed to characterize complicated fiber patterns and distinguish fiber orientations, providing an opportunity for more accurate, higher-order descriptions through the water diffusion process. Therefore, we aimed to investigate differences in the brain's structural network between teenage males and females using GQI. This study included 59 (i.e., 33 males and 26 females) age- and education-matched subjects (age range: 13 to 14 years). The structural connectome was obtained by graph theoretical and network-based statistical (NBS) analyses. Our findings show that teenage male brains exhibit better intrahemispheric communication, and teenage female brains exhibit better interhemispheric communication. Our results also suggest that the network organization of teenage male brains is more local, more segregated, and more similar to small-world networks than teenage female brains. We conclude that the use of an MRI study with a GQI-based structural connectomic approach like ours presents novel insights into network-based systems of the brain and provides a new piece of the puzzle regarding gender differences.

  4. The implicit effect of texturizing field on the elastic properties of magnetic elastomers revealed by SANS

    Energy Technology Data Exchange (ETDEWEB)

    Balasoiu, M., E-mail: balas@jinr.ru [Joint Institute of Nuclear Research, Dubna (Russian Federation); Horia Hulubei National Institute for Physics and Nuclear Engineering, Bucharest (Romania); Lebedev, V.T. [St.Petersburg Nuclear Physics Institute NRC KI, Gatchina (Russian Federation); Raikher, Yu.L. [Institute of Continuous Media Mechanics, Russian Academy of Sciences, Ural Branch, Perm (Russian Federation); Bica, I.; Bunoiu, M. [West University of Timisoara, Department of Physics (Romania)

    2017-06-01

    Small angle neutron scattering method (SANS) is used to characterize the structure properties of the polymer matrix of magnetic elastomers (MEs) of the same material content but with different magnetic textures. For that, series of silicone-rubber elastomers mixed with a ferrofluid and polymerized with/without external magnetic field were studied. In the species of pure rubber and the ME samples synthesized without field, SANS reveals a substantial number of large polymer coils (blobs) which are vertically prolate. The case of MEs polymerized under the magnetic field that is also vertically directed, is different. SANS data indicates that there the blobs are preferably elongated in the direction normal to the field. - Highlights: • SANS method is used to determine the structure of SR elastomers polymerized with ferrofluid in/no external magnetic field. • In the rubber and ME samples synthesized without field, SANS reveals a substantial number of vertically prolate blobs. • For MEs polymerized in vertical magnetic field, results that the blobs are elongated in the direction normal to the field. • Isotropic and texturized MEs differ by the filler structure and by intrinsic elastic properties of the matrix as well.

  5. The perils of straying from protocol: sampling bias and interviewer effects.

    Directory of Open Access Journals (Sweden)

    Carrie J Ngongo

    Full Text Available Fidelity to research protocol is critical. In a contingent valuation study in an informal urban settlement in Nairobi, Kenya, participants responded differently to the three trained interviewers. Interviewer effects were present during the survey pilot, then magnified at the start of the main survey after a seemingly slight adaptation of the survey sampling protocol allowed interviewers to speak with the "closest neighbor" in the event that no one was home at a selected household. This slight degree of interviewer choice led to inferred sampling bias. Multinomial logistic regression and post-estimation tests revealed that the three interviewers' samples differed significantly from one another according to six demographic characteristics. The two female interviewers were 2.8 and 7.7 times less likely to talk with respondents of low socio-economic status than the male interviewer. Systematic error renders it impossible to determine which of the survey responses might be "correct." This experience demonstrates why researchers must take care to strictly follow sampling protocols, consistently train interviewers, and monitor responses by interview to ensure similarity between interviewers' groups and produce unbiased estimates of the parameters of interest.

  6. Study of phosphors determination in biological samples; Estudo da determinacao de fosforo em amostras biologicas

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Rosangela Magda de

    1994-12-31

    In this paper, phosphors determination by neutron activation analysis in milk and bone samples was studied employing both instrumental and radiochemical separation methods. The analysis with radiochemistry separation consisted of the simultaneous irradiation of the samples and standards during 30 minutes, dissolution of the samples, hold back carrier, addition precipitation of phosphorus with ammonium phosphomolibdate (A.M.P.) and phosphorus-32 by counting by using Geiger-Mueller detector. The instrumental analysis consisted of the simultaneous irradiation of the samples and standards during 30 minutes, transfer of the samples into a counting planchet and measurement of the beta radiation emitted by phosphorus-32, after a suitable decay period. After the phosphorus analysis methods were established they were applied to both commercial milk and animal bone samples, and data obtained in the instrumental and radiochemical separation methods for each sample, were compared between themselves. In this work, it became possible to obtain analysis methods for phosphorus that can be applied independently of the sample quantity available, and the phosphorus content in the samples or interference that can be present in them. (author). 51 refs., 7 figs., 4 tabs.

  7. 1H NMR-based metabolic profiling reveals inherent biological variation in yeast and nematode model systems

    International Nuclear Information System (INIS)

    Szeto, Samuel S. W.; Reinke, Stacey N.; Lemire, Bernard D.

    2011-01-01

    The application of metabolomics to human and animal model systems is poised to provide great insight into our understanding of disease etiology and the metabolic changes that are associated with these conditions. However, metabolomic studies have also revealed that there is significant, inherent biological variation in human samples and even in samples from animal model systems where the animals are housed under carefully controlled conditions. This inherent biological variability is an important consideration for all metabolomics analyses. In this study, we examined the biological variation in 1 H NMR-based metabolic profiling of two model systems, the yeast Saccharomyces cerevisiae and the nematode Caenorhabditis elegans. Using relative standard deviations (RSD) as a measure of variability, our results reveal that both model systems have significant amounts of biological variation. The C. elegans metabolome possesses greater metabolic variance with average RSD values of 29 and 39%, depending on the food source that was used. The S. cerevisiae exometabolome RSD values ranged from 8% to 12% for the four strains examined. We also determined whether biological variation occurs between pairs of phenotypically identical yeast strains. Multivariate statistical analysis allowed us to discriminate between pair members based on their metabolic phenotypes. Our results highlight the variability of the metabolome that exists even for less complex model systems cultured under defined conditions. We also highlight the efficacy of metabolic profiling for defining these subtle metabolic alterations.

  8. Fluorescence imaging of sample zone narrowing and dispersion in a glass microchip: the effects of organic solvent (acetonitrile)-salt mixtures in the sample matrix and surfactant micelles in the running buffer.

    Science.gov (United States)

    Jia, Zhijian; Lee, Yi-kuen; Fang, Qun; Huie, Carmen W

    2006-03-01

    A mismatch in the EOF velocities between the sample zone and running buffer region is known to generate pressure-driven, parabolic flow profile of the sample plug in electrokinetic separation systems. In the present study, video fluorescence microscopy was employed to capture real-time dynamics of the sample plug (containing fluorescein as the probe molecule) in a discontinuous conductivity system within a glass microchip, in which the sample matrix consisted of a mixture of ACN and salt (NaCl), and the running buffer contained sodium cholate (SC) micelles as the pseudo-stationary phase (i.e., performing "ACN stacking" in the mode of MEKC). Upon application of the separation voltage, the video images revealed that zone narrowing and broadening of the probe molecules occurred as the sample plug headed toward the cathode during the initial time period, probably resulting in part from the stacking/sweeping, and destacking of the SC micelles at the boundaries between the sample zone and running buffer. Interestingly, a second sample zone narrowing event can be observed as the sample plug moved further toward the cathode, which could be attributed to the sweeping of the slower moving probe molecules by the faster moving SC micelles that originated from the anode. This phenomenon was studied as a function of pH, sample plug length, as well as the concentration of organic solvent and salt in the sample matrix. The data suggested that the presence of large amounts of an organic solvent (such as ACN or methanol) and salts in the sample matrix not only induces sample dispersion due to the formation of a pressure-driven (hydrodynamic) flow, but may also lead to the formation of a double sample zone narrowing phenomenon by altering the local EOF dynamics within the separation system.

  9. Comprehensive Genomic Profiling of Esthesioneuroblastoma Reveals Additional Treatment Options.

    Science.gov (United States)

    Gay, Laurie M; Kim, Sungeun; Fedorchak, Kyle; Kundranda, Madappa; Odia, Yazmin; Nangia, Chaitali; Battiste, James; Colon-Otero, Gerardo; Powell, Steven; Russell, Jeffery; Elvin, Julia A; Vergilio, Jo-Anne; Suh, James; Ali, Siraj M; Stephens, Philip J; Miller, Vincent A; Ross, Jeffrey S

    2017-07-01

    Esthesioneuroblastoma (ENB), also known as olfactory neuroblastoma, is a rare malignant neoplasm of the olfactory mucosa. Despite surgical resection combined with radiotherapy and adjuvant chemotherapy, ENB often relapses with rapid progression. Current multimodality, nontargeted therapy for relapsed ENB is of limited clinical benefit. We queried whether comprehensive genomic profiling (CGP) of relapsed or refractory ENB can uncover genomic alterations (GA) that could identify potential targeted therapies for these patients. CGP was performed on formalin-fixed, paraffin-embedded sections from 41 consecutive clinical cases of ENBs using a hybrid-capture, adaptor ligation based next-generation sequencing assay to a mean coverage depth of 593X. The results were analyzed for base substitutions, insertions and deletions, select rearrangements, and copy number changes (amplifications and homozygous deletions). Clinically relevant GA (CRGA) were defined as GA linked to drugs on the market or under evaluation in clinical trials. A total of 28 ENBs harbored GA, with a mean of 1.5 GA per sample. Approximately half of the ENBs (21, 51%) featured at least one CRGA, with an average of 1 CRGA per sample. The most commonly altered gene was TP53 (17%), with GA in PIK3CA , NF1 , CDKN2A , and CDKN2C occurring in 7% of samples. We report comprehensive genomic profiles for 41 ENB tumors. CGP revealed potential new therapeutic targets, including targetable GA in the mTOR, CDK and growth factor signaling pathways, highlighting the clinical value of genomic profiling in ENB. Comprehensive genomic profiling of 41 relapsed or refractory ENBs reveals recurrent alterations or classes of mutation, including amplification of tyrosine kinases encoded on chromosome 5q and mutations affecting genes in the mTOR/PI3K pathway. Approximately half of the ENBs (21, 51%) featured at least one clinically relevant genomic alteration (CRGA), with an average of 1 CRGA per sample. The most commonly altered

  10. Water evaporation: a transition path sampling study.

    Science.gov (United States)

    Varilly, Patrick; Chandler, David

    2013-02-07

    We use transition path sampling to study evaporation in the SPC/E model of liquid water. On the basis of thousands of evaporation trajectories, we characterize the members of the transition state ensemble (TSE), which exhibit a liquid-vapor interface with predominantly negative mean curvature at the site of evaporation. We also find that after evaporation is complete, the distributions of translational and angular momenta of the evaporated water are Maxwellian with a temperature equal to that of the liquid. To characterize the evaporation trajectories in their entirety, we find that it suffices to project them onto just two coordinates: the distance of the evaporating molecule to the instantaneous liquid-vapor interface and the velocity of the water along the average interface normal. In this projected space, we find that the TSE is well-captured by a simple model of ballistic escape from a deep potential well, with no additional barrier to evaporation beyond the cohesive strength of the liquid. Equivalently, they are consistent with a near-unity probability for a water molecule impinging upon a liquid droplet to condense. These results agree with previous simulations and with some, but not all, recent experiments.

  11. Sampling design considerations for demographic studies: a case of colonial seabirds

    Science.gov (United States)

    Kendall, William L.; Converse, Sarah J.; Doherty, Paul F.; Naughton, Maura B.; Anders, Angela; Hines, James E.; Flint, Elizabeth

    2009-01-01

    For the purposes of making many informed conservation decisions, the main goal for data collection is to assess population status and allow prediction of the consequences of candidate management actions. Reducing the bias and variance of estimates of population parameters reduces uncertainty in population status and projections, thereby reducing the overall uncertainty under which a population manager must make a decision. In capture-recapture studies, imperfect detection of individuals, unobservable life-history states, local movement outside study areas, and tag loss can cause bias or precision problems with estimates of population parameters. Furthermore, excessive disturbance to individuals during capture?recapture sampling may be of concern because disturbance may have demographic consequences. We address these problems using as an example a monitoring program for Black-footed Albatross (Phoebastria nigripes) and Laysan Albatross (Phoebastria immutabilis) nesting populations in the northwestern Hawaiian Islands. To mitigate these estimation problems, we describe a synergistic combination of sampling design and modeling approaches. Solutions include multiple capture periods per season and multistate, robust design statistical models, dead recoveries and incidental observations, telemetry and data loggers, buffer areas around study plots to neutralize the effect of local movements outside study plots, and double banding and statistical models that account for band loss. We also present a variation on the robust capture?recapture design and a corresponding statistical model that minimizes disturbance to individuals. For the albatross case study, this less invasive robust design was more time efficient and, when used in combination with a traditional robust design, reduced the standard error of detection probability by 14% with only two hours of additional effort in the field. These field techniques and associated modeling approaches are applicable to studies of

  12. Development study of the X-ray scattering properties of a group of optically polished flat samples

    Science.gov (United States)

    Froechtenigt, J. F.

    1973-01-01

    A group of twelve optically polished flat samples were used to study the scattering of X-rays. The X-ray beam reflected from the twelve optical flat samples was analyzed by means of a long vacuum system of special design for these tests. The scattering measurements were made at 8.34A and 0.92 deg angle of incidence. The results for ten of the samples are comparable, the two exceptions being the fire polished samples.

  13. Studies on the radiocarbon sample from the shroud of turin

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, Raymond N. [Los Alamos National Laboratory, University of California, 1961 Cumbres Patio, Los Alamos, NM 87544 (United States)]. E-mail: rnrogers@att.net

    2005-01-20

    In 1988, radiocarbon laboratories at Arizona, Cambridge, and Zurich determined the age of a sample from the Shroud of Turin. They reported that the date of the cloth's production lay between A.D. 1260 and 1390 with 95% confidence. This came as a surprise in view of the technology used to produce the cloth, its chemical composition, and the lack of vanillin in its lignin. The results prompted questions about the validity of the sample. Preliminary estimates of the kinetics constants for the loss of vanillin from lignin indicate a much older age for the cloth than the radiocarbon analyses. The radiocarbon sampling area is uniquely coated with a yellow-brown plant gum containing dye lakes. Pyrolysis-mass-spectrometry results from the sample area coupled with microscopic and microchemical observations prove that the radiocarbon sample was not part of the original cloth of the Shroud of Turin. The radiocarbon date was thus not valid for determining the true age of the shroud.

  14. Studies on the radiocarbon sample from the shroud of turin

    International Nuclear Information System (INIS)

    Rogers, Raymond N.

    2005-01-01

    In 1988, radiocarbon laboratories at Arizona, Cambridge, and Zurich determined the age of a sample from the Shroud of Turin. They reported that the date of the cloth's production lay between A.D. 1260 and 1390 with 95% confidence. This came as a surprise in view of the technology used to produce the cloth, its chemical composition, and the lack of vanillin in its lignin. The results prompted questions about the validity of the sample. Preliminary estimates of the kinetics constants for the loss of vanillin from lignin indicate a much older age for the cloth than the radiocarbon analyses. The radiocarbon sampling area is uniquely coated with a yellow-brown plant gum containing dye lakes. Pyrolysis-mass-spectrometry results from the sample area coupled with microscopic and microchemical observations prove that the radiocarbon sample was not part of the original cloth of the Shroud of Turin. The radiocarbon date was thus not valid for determining the true age of the shroud

  15. Joint importance sampling of low-order volumetric scattering

    DEFF Research Database (Denmark)

    Georgiev, Iliyan; Křivánek, Jaroslav; Hachisuka, Toshiya

    2013-01-01

    Central to all Monte Carlo-based rendering algorithms is the construction of light transport paths from the light sources to the eye. Existing rendering approaches sample path vertices incrementally when constructing these light transport paths. The resulting probability density is thus a product...... of the conditional densities of each local sampling step, constructed without explicit control over the form of the final joint distribution of the complete path. We analyze why current incremental construction schemes often lead to high variance in the presence of participating media, and reveal...... that such approaches are an unnecessary legacy inherited from traditional surface-based rendering algorithms. We devise joint importance sampling of path vertices in participating media to construct paths that explicitly account for the product of all scattering and geometry terms along a sequence of vertices instead...

  16. Lack of tissue renewal in human adult Achilles tendon is revealed by nuclear bomb C

    DEFF Research Database (Denmark)

    Heinemeier, Katja Maria; Schjerling, Peter; Heinemeier, J.

    2013-01-01

    the 14C bomb-pulse method. This method takes advantage of the dramatic increase in atmospheric levels of 14C, produced by nuclear bomb tests in 1955-1963, which is reflected in all living organisms. Levels of 14C were measured in 28 forensic samples of Achilles tendon core and 4 skeletal muscle samples...... is revealed by nuclear bomb 14C....

  17. Drop-on-Demand Sample Delivery for Studying Biocatalysts in Action at XFELs

    Science.gov (United States)

    Fuller, Franklin D.; Gul, Sheraz; Chatterjee, Ruchira; Burgie, Ernest S.; Young, Iris D.; Lebrette, Hugo; Srinivas, Vivek; Brewster, Aaron S.; Michels-Clark, Tara; Clinger, Jonathan A.; Andi, Babak; Ibrahim, Mohamed; Pastor, Ernest; de Lichtenberg, Casper; Hussein, Rana; Pollock, Christopher J.; Zhang, Miao; Stan, Claudiu A.; Kroll, Thomas; Fransson, Thomas; Weninger, Clemens; Kubin, Markus; Aller, Pierre; Lassalle, Louise; Bräuer, Philipp; Miller, Mitchell D.; Amin, Muhamed; Koroidov, Sergey; Roessler, Christian G.; Allaire, Marc; Sierra, Raymond G.; Docker, Peter T.; Glownia, James M.; Nelson, Silke; Koglin, Jason E.; Zhu, Diling; Chollet, Matthieu; Song, Sanghoon; Lemke, Henrik; Liang, Mengning; Sokaras, Dimosthenis; Alonso-Mori, Roberto; Zouni, Athina; Messinger, Johannes; Bergmann, Uwe; Boal, Amie K.; Bollinger, J. Martin; Krebs, Carsten; Högbom, Martin; Phillips, George N.; Vierstra, Richard D.; Sauter, Nicholas K.; Orville, Allen M.; Kern, Jan; Yachandra, Vittal K.; Yano, Junko

    2017-01-01

    X-ray crystallography at X-ray free-electron laser (XFEL) sources is a powerful method for studying macromolecules at biologically relevant temperatures. Moreover, when combined with complementary techniques like X-ray emission spectroscopy (XES), both global structures and chemical properties of metalloenzymes can be obtained concurrently, providing new insights into the interplay between the protein structure/dynamics and chemistry at an active site. Implementing such a multimodal approach can be compromised by conflicting requirements to optimize each individual method. In particular, the method used for sample delivery greatly impacts the data quality. We present here a new, robust way of delivering controlled sample amounts on demand using acoustic droplet ejection coupled with a conveyor belt drive that is optimized for crystallography and spectroscopy measurements of photochemical and chemical reactions over a wide range of time scales. Studies with photosystem II, the phytochrome photoreceptor, and ribonucleotide reductase R2 illustrate the power and versatility of this method. PMID:28250468

  18. Whole genome transcript profiling from fingerstick blood samples: a comparison and feasibility study

    Directory of Open Access Journals (Sweden)

    Williams Adam R

    2009-12-01

    Full Text Available Abstract Background Whole genome gene expression profiling has revolutionized research in the past decade especially with the advent of microarrays. Recently, there have been significant improvements in whole blood RNA isolation techniques which, through stabilization of RNA at the time of sample collection, avoid bias and artifacts introduced during sample handling. Despite these improvements, current human whole blood RNA stabilization/isolation kits are limited by the requirement of a venous blood sample of at least 2.5 mL. While fingerstick blood collection has been used for many different assays, there has yet to be a kit developed to isolate high quality RNA for use in gene expression studies from such small human samples. The clinical and field testing advantages of obtaining reliable and reproducible gene expression data from a fingerstick are many; it is less invasive, time saving, more mobile, and eliminates the need of a trained phlebotomist. Furthermore, this method could also be employed in small animal studies, i.e. mice, where larger sample collections often require sacrificing the animal. In this study, we offer a rapid and simple method to extract sufficient amounts of high quality total RNA from approximately 70 μl of whole blood collected via a fingerstick using a modified protocol of the commercially available Qiagen PAXgene RNA Blood Kit. Results From two sets of fingerstick collections, about 70 uL whole blood collected via finger lancet and capillary tube, we recovered an average of 252.6 ng total RNA with an average RIN of 9.3. The post-amplification yields for 50 ng of total RNA averaged at 7.0 ug cDNA. The cDNA hybridized to Affymetrix HG-U133 Plus 2.0 GeneChips had an average % Present call of 52.5%. Both fingerstick collections were highly correlated with r2 values ranging from 0.94 to 0.97. Similarly both fingerstick collections were highly correlated to the venous collection with r2 values ranging from 0.88 to 0

  19. Metabolomics reveals variation and correlation among different tissues of olive (Olea europaea L.

    Directory of Open Access Journals (Sweden)

    Rao Guodong

    2017-09-01

    Full Text Available Metabolites in olives are associated with nutritional value and physiological properties. However, comprehensive information regarding the olive metabolome is limited. In this study, we identified 226 metabolites from three different tissues of olive using a non-targeted metabolomic profiling approach, of which 76 named metabolites were confirmed. Further statistical analysis revealed that these 76 metabolites covered different types of primary metabolism and some of the secondary metabolism pathways. One-way analysis of variance (ANOVA statistical assay was performed to calculate the variations within the detected metabolites, and levels of 65 metabolites were differentially expressed in different samples. Hierarchical cluster analysis (HCA dendrograms showed variations among different tissues that were similar to the metabolite profiles observed in new leaves and fruit. Additionally, 5776 metabolite-metabolite correlations were detected by a Pearson correlation coefficient approach. Screening of the calculated correlations revealed 3136, 3025, and 5184 were determined to metabolites and had significant correlations in three different combinations, respectively. This work provides the first comprehensive metabolomic of olive, which will provide new insights into understanding the olive metabolism, and potentially help advance studies in olive metabolic engineering.

  20. Revealed Preference Methods for Studying Bicycle Route Choice—A Systematic Review

    Directory of Open Access Journals (Sweden)

    Ray Pritchard

    2018-03-01

    Full Text Available One fundamental aspect of promoting utilitarian bicycle use involves making modifications to the built environment to improve the safety, efficiency and enjoyability of cycling. Revealed preference data on bicycle route choice can assist greatly in understanding the actual behaviour of a highly heterogeneous group of users, which in turn assists the prioritisation of infrastructure or other built environment initiatives. This systematic review seeks to compare the relative strengths and weaknesses of the empirical approaches for evaluating whole journey route choices of bicyclists. Two electronic databases were systematically searched for a selection of keywords pertaining to bicycle and route choice. In total seven families of methods are identified: GPS devices, smartphone applications, crowdsourcing, participant-recalled routes, accompanied journeys, egocentric cameras and virtual reality. The study illustrates a trade-off in the quality of data obtainable and the average number of participants. Future additional methods could include dockless bikeshare, multiple camera solutions using computer vision and immersive bicycle simulator environments.

  1. The radioactivity of meat samples between 1977 and 1982

    International Nuclear Information System (INIS)

    Zalabai, Bela

    1983-01-01

    90 Sr and 137 Cs from atmospheric nuclear explosions can get into the organizations of domestic animals via fodder. Radiological tests of meat samples revealed a load maximum last time in 1976. The regular tests of pork and beef samples between 1977 and 1982 in Hungary showed no significant differences in their radiocesium contents. The change of strontium activity in bones, however, lasts longer than that of cesium. According to the measurements, the strontium activity in swine bones was almost one order lower than that in cattle bones. (Sz.J.)

  2. A Study of the Vaginal Microbiome in Healthy Canadian Women Utilizing cpn60-Based Molecular Profiling Reveals Distinct Gardnerella Subgroup Community State Types

    Science.gov (United States)

    Wagner, Emily C.; Schellenberg, John J.; Links, Matthew G.; van Schalkwyk, Julie; Reid, Gregor; Hemmingsen, Sean M.; Hill, Janet E.; Money, Deborah

    2015-01-01

    The vaginal microbiota is important in women’s reproductive and overall health. However, the relationships between the structure, function and dynamics of this complex microbial community and health outcomes remain elusive. The objective of this study was to determine the phylogenetic range and abundance of prokaryotes in the vaginal microbiota of healthy, non-pregnant, ethnically diverse, reproductive-aged Canadian women. Socio-demographic, behavioural and clinical data were collected and vaginal swabs were analyzed from 310 women. Detailed profiles of their vaginal microbiomes were generated by pyrosequencing of the chaperonin-60 universal target. Six community state types (CST) were delineated by hierarchical clustering, including three Lactobacillus-dominated CST (L. crispatus, L. iners, L. jensenii), two Gardnerella-dominated (subgroups A and C) and an “intermediate” CST which included a small number of women with microbiomes dominated by seven other species or with no dominant species but minority populations of Streptococcus, Staphylococcus, Peptoniphilus, E. coli and various Proteobacteria in co-dominant communities. The striking correspondence between Nugent score and deep sequencing CST continues to reinforce the basic premise provided by the simpler Gram stain method, while additional analyses reveal detailed cpn60-based phylogeny and estimated abundance in microbial communities from vaginal samples. Ethnicity was the only demographic or clinical characteristic predicting CST, with differences in Asian and White women (p = 0.05). In conclusion, this study confirms previous work describing four cpn60-based subgroups of Gardnerella, revealing previously undescribed CST. The data describe the range of bacterial communities seen in Canadian women presenting with no specific vaginal health concerns, and provides an important baseline for future investigations of clinically important cohorts. PMID:26266808

  3. Ceres Revealed in a Grain of Salt

    Science.gov (United States)

    Zolensky, M. E.; Bodnar, R. J.; Fries, M.; Chan, Q. H.-S.; Kebukawa, Y.; Mikouchi, T.; Hagiya, K.; Komatsu, M.; Ohsumi, K.; Steele, A.

    2016-01-01

    Introduction: Zag and Monahans (1998) are H chondrite regolith breccias containing 4.5 giga-year-old halite crystals which contain abundant inclusions of aqueous fluids, solids and organics. These all originated on a cryo-volcanically-active C class asteroid, probably 1 Ceres; the halite was transported to the regolith of the H chondrite parent asteroid, potentially 6 Hebe. Detailed analysis of these solids will thus potentially reveal the mineralogy of Ceres. Mineralogy of solids in the Monahans Halite Solid grains are present in the halites, which were entrained within the mother brines during eruption, including material from the interior and surface of the erupting body. The solids include abundant, widely variable organics that could not have been significantly heated (which would have resulted in the loss of fluids from the halite). Our analyses by Raman microprobe, SEM/EDX, synchrotron X-ray diffraction, UPLC-FD/QToF-MS, C-XANES and TEM reveal that these trapped grains include macromolecular carbon (MMC) similar in structure to CV3 chondrite matrix carbon, aliphatic carbon compounds, olivine (Fo99-59), high- and low-Ca pyroxene, feldspars, phyllosilicates, magnetite, sulfides, metal, lepidocrocite, carbonates, diamond, apatite and zeolites. Conclusions: The halite in Monahans and Zag derive from a water and carbon-rich object that was cryo-volcanically active in the early solar system, probably Ceres. The Dawn spacecraft found that Ceres includes C chondrite materials. Our samples include both protolith and aqueously-altered samples of the body, permitting understanding of alteration conditions. Whatever the halite parent body, it was rich in a wide variety of organics and warm, liquid water at the solar system's dawn.

  4. Ophthalmologic changes related to radiation exposure and age in the adult health study sample, Hiroshima and Nagasaki

    International Nuclear Information System (INIS)

    Choshi, Kanji; Mishima, Hiromu; Takaku, Isao; Takase, Tomoko; Neriishi, Shotaro.

    1983-11-01

    A two-year ophthalmologic study of age- and radiation-related ophthalmologic lesions among the Adult Health Study (AHS) population of Hiroshima and Nagasaki was conducted at RERF in 1978-80. The study population in both cities was composed of all persons exposed to 100+ rad in the AHS, their controls, and all other persons in the AHS sample with a previous record of axial opacities or posterior subcapsular changes, and the in utero clinical sample. The ophthalmologic examination was conducted on 1,582 persons in Hiroshima and 719 persons in Nagasaki belonging to the AHS sample, and 67 persons in Hiroshima and 17 persons in Nagasaki belonging to the in utero clinical sample. Participation in the study was 42% of the eligible AHS sample in Hiroshima and 21% in Nagasaki, and 24% of the eligible in utero sample in Hiroshima and 26% in Nagasaki. Increased lenticular opacities, other lens changes, and loss of visual acuity and accommodation occurred with increasing age in both exposed and control subjects as manifestations of the normal aging process. A highly significant excess risk for all ages in the 300+ rad group in comparison to those in the control group was observed for both axial opacities and posterior subcapsular changes in Hiroshima, but not in Nagasaki. (J.P.N.)

  5. A model for estimating the minimum number of offspring to sample in studies of reproductive success.

    Science.gov (United States)

    Anderson, Joseph H; Ward, Eric J; Carlson, Stephanie M

    2011-01-01

    Molecular parentage permits studies of selection and evolution in fecund species with cryptic mating systems, such as fish, amphibians, and insects. However, there exists no method for estimating the number of offspring that must be assigned parentage to achieve robust estimates of reproductive success when only a fraction of offspring can be sampled. We constructed a 2-stage model that first estimated the mean (μ) and variance (v) in reproductive success from published studies on salmonid fishes and then sampled offspring from reproductive success distributions simulated from the μ and v estimates. Results provided strong support for modeling salmonid reproductive success via the negative binomial distribution and suggested that few offspring samples are needed to reject the null hypothesis of uniform offspring production. However, the sampled reproductive success distributions deviated significantly (χ(2) goodness-of-fit test p value reproductive success distribution at rates often >0.05 and as high as 0.24, even when hundreds of offspring were assigned parentage. In general, reproductive success patterns were less accurate when offspring were sampled from cohorts with larger numbers of parents and greater variance in reproductive success. Our model can be reparameterized with data from other species and will aid researchers in planning reproductive success studies by providing explicit sampling targets required to accurately assess reproductive success.

  6. Omics strategies for revealing Yersinia pestis virulence

    Science.gov (United States)

    Yang, Ruifu; Du, Zongmin; Han, Yanping; Zhou, Lei; Song, Yajun; Zhou, Dongsheng; Cui, Yujun

    2012-01-01

    Omics has remarkably changed the way we investigate and understand life. Omics differs from traditional hypothesis-driven research because it is a discovery-driven approach. Mass datasets produced from omics-based studies require experts from different fields to reveal the salient features behind these data. In this review, we summarize omics-driven studies to reveal the virulence features of Yersinia pestis through genomics, trascriptomics, proteomics, interactomics, etc. These studies serve as foundations for further hypothesis-driven research and help us gain insight into Y. pestis pathogenesis. PMID:23248778

  7. Sampling on Quasicrystals

    OpenAIRE

    Grepstad, Sigrid

    2011-01-01

    We prove that quasicrystals are universal sets of stable sampling in any dimension. Necessary and sufficient density conditions for stable sampling and interpolation sets in one dimension are studied in detail.

  8. Preparation of solid-state samples of a transition metal coordination compound for synchrotron radiation photoemission studies

    CERN Document Server

    Crotti, C; Celestino, T; Fontana, S

    2003-01-01

    The aim of this research was to identify a sample preparation method suitable for the study of transition metal complexes by photoemission spectroscopy with synchrotron radiation as the X-ray source, even in the case where the compound is not evaporable. Solid-phase samples of W(CO) sub 4 (dppe) [dppe=1,2-bis(diphenylphosphino)ethane] were prepared according to different methods and their synchrotron radiation XPS spectra measured. The spectra acquired from samples prepared by spin coating show core level peaks only slightly broader than the spectrum recorded from UHV evaporated samples. Moreover, for these samples the reproducibility of the binding energy values is excellent. The dependence of the spin coating technique on parameters such as solvent and solution concentration, spinning speed and support material was studied. The same preparation method also allowed the acquisition of valence band spectra, the main peaks of which were clearly resolved. The results suggest that use of the spin coating techniqu...

  9. Long-Term Field Study Reveals Subtle Effects of the Invasive Alga Sargassum muticum upon the Epibiota of Zostera marina.

    Directory of Open Access Journals (Sweden)

    Stacey DeAmicis

    Full Text Available Invasive species can alter coastal ecosystems both directly, e.g. through competition for substratum and nutrients, and indirectly. Indirect effects may be mediated by creation of dissimilar or inimical habitats, changes in predator and/or prey assemblages, alterations in associated biota, and perturbations of water movement and thermal regimes. Previous studies have shown that invasive algae can modify native habitat architecture, disrupt intricately linked food webs and alter epibiotic assemblages. In the UK, the seagrass Zostera marina supports a diverse epibiotic assemblage, influencing key factors such as sediment dynamics, depositional regime and trophic linkages. Increasing encroachment of the invasive alga Sargassum muticum into seagrass meadows changes the physical and chemical characteristics of the local environment and creates the potential for changes in the epibionts associated with the seagrass blades, threatening the integrity of the seagrass ecosystem. We investigated the effects of S. muticum invasion upon the epibiota of Z. marina in a drowned river valley in SW England seasonally from spring to autumn over four years in an in-situ manipulative experiment, comparing permanent quadrats with and without artificially introduced S. muticum. Epibiota were weighed, identified to the most detailed operational taxonomic unit (OTU possible, and unitary organisms were enumerated. Multivariate PERMANOVA+ analysis revealed significant differences in epibiont assemblages between Sargassum treatments. Linear mixed effects models indicated that differences in epibiota assemblage composition were not reflected as significant differences in mean biomass per sample, or number of epibiont OTUs per sample. We conclude that S. muticum invasion into Z. marina meadows may significantly alter the species composition and abundance distribution of epibiotic assemblages found on the blades of the seagrass. Thus S. muticum invasion could have more wide

  10. The Luna 16 and Luna 20 samples and their integrated studies in India

    International Nuclear Information System (INIS)

    Lal, D.

    1974-01-01

    The results of an integrated study of physical and chemical properties of lunar samples returned to earth by the automatic Soviet stations Luna 16 and 20 carried out with a view to dilineate the evolutionary history of moon, are reported. The nature of the Luna 16 and Luna 20 landing sites and lunar samples, and the manner in which the integrated analyses were planned and executed, are discussed. It is noted that the two lunar missions have provided a wealth of new information in unravelling the early history of planetary formation. (A.K.)

  11. Size Distributions and Characterization of Native and Ground Samples for Toxicology Studies

    Science.gov (United States)

    McKay, David S.; Cooper, Bonnie L.; Taylor, Larry A.

    2010-01-01

    This slide presentation shows charts and graphs that review the particle size distribution and characterization of natural and ground samples for toxicology studies. There are graphs which show the volume distribution versus the number distribution for natural occurring dust, jet mill ground dust, and ball mill ground dust.

  12. FREQUENCY OF ANEUPLOID SPERMATOZOA STUDIED BY MULTICOLOR FISH IN SERIAL SEMEN SAMPLES

    Science.gov (United States)

    Frequency of aneuploid spermatozoa studied by multicolor FISH in serial semen samplesM. Vozdova1, S. D. Perreault2, O. Rezacova1, D. Zudova1 , Z. Zudova3, S. G. Selevan4, J. Rubes1,51Veterinary Research Institute, Brno, Czech Republic; 2U.S. Environmental Protection A...

  13. Genotoxicity studies in semiconductor industry. 1. In vitro mutagenicity and genotoxicity studies of waste samples resulting from plasma etching

    Energy Technology Data Exchange (ETDEWEB)

    Braun, R.; Huettner, E.M.; Merten, H.; Raabe, F. (Institute of Plant Genetics and Crop Plant Research, Gatersleben (Germany))

    1993-07-01

    Solid waste samples taken from the etching reactor, the turbo pump, and the waste air system of a plasma etching technology line in semiconductor production were studied as to their genotoxic properties in a bacterial repair test, in the Ames/Salmonella microsome assay, in the SOS chromotest, in primary mouse hepatocytes, and in Chinese hamster V79 cell cultures. All three waste samples were found to be active by inducing of unscheduled DNA-synthesis in mouse hepatocytes in vitro. In the bacterial rec-type repair test with Proteus mirabilis, waste samples taken from the turbo pump and the vacuum pipe system were not genotoxic. The waste sample taken from the chlorine-mediated plasma reactor was clearly positive in the bacterial repair assay and in the SOS chromotest with Escherichia coli. Mutagenic activity was demonstrated for all samples in the presence and absence of S9 mix made from mouse liver homogenate. Again, highest mutagenic activity was recorded for the waste sample taken from the plasma reactor, while samples collected from the turbo pump and from the waste air system before dilution and liberation of the air were less mutagenic. For all samples chromosomal damage in V79 cells was not detected, indicating absence of clastogenic activity in vitro. Altogether, these results indicate generation of genotoxic and mutagenic products as a consequence of chlorine-mediated plasma etching in the microelectronics industry and the presence of genotoxins even in places distant from the plasma reactor. Occupational exposure can be expected both from the precipitated wastes and from chemicals reaching the environment with the air stream.

  14. 14C sample preparation for AMS microdosing studies at Lund University using online combustion and septa-sealed vials

    Science.gov (United States)

    Sydoff, Marie; Stenström, Kristina

    2010-04-01

    The Department of Physics at Lund University is participating in a European Union project called EUMAPP (European Union Microdose AMS Partnership Programme), in which sample preparation and accelerator mass spectrometry (AMS) measurements of biological samples from microdosing studies have been made. This paper describes a simplified method of converting biological samples to solid graphite for 14C analysis with AMS. The method is based on online combustion of the samples, and reduction of CO 2 in septa-sealed vials. The septa-sealed vials and disposable materials are used to eliminate sample cross-contamination. Measurements of ANU and Ox I standards show deviations of 2% and 3%, respectively, relative to reference values. This level of accuracy is sufficient for biological samples from microdosing studies. Since the method has very few handling steps from sample to graphite, the risk of failure during the sample preparation process is minimized, making the method easy to use in routine preparation of samples.

  15. 14C sample preparation for AMS microdosing studies at Lund University using online combustion and septa-sealed vials

    International Nuclear Information System (INIS)

    Sydoff, Marie; Stenstroem, Kristina

    2010-01-01

    The Department of Physics at Lund University is participating in a European Union project called EUMAPP (European Union Microdose AMS Partnership Programme), in which sample preparation and accelerator mass spectrometry (AMS) measurements of biological samples from microdosing studies have been made. This paper describes a simplified method of converting biological samples to solid graphite for 14 C analysis with AMS. The method is based on online combustion of the samples, and reduction of CO 2 in septa-sealed vials. The septa-sealed vials and disposable materials are used to eliminate sample cross-contamination. Measurements of ANU and Ox I standards show deviations of 2% and 3%, respectively, relative to reference values. This level of accuracy is sufficient for biological samples from microdosing studies. Since the method has very few handling steps from sample to graphite, the risk of failure during the sample preparation process is minimized, making the method easy to use in routine preparation of samples.

  16. 3-dimensional examination of the adult mouse subventricular zone reveals lineage-specific microdomains.

    Directory of Open Access Journals (Sweden)

    Kasum Azim

    Full Text Available Recent studies suggest that the subventricular zone (SVZ of the lateral ventricle is populated by heterogeneous populations of stem and progenitor cells that, depending on their exact location, are biased to acquire specific neuronal fates. This newly described heterogeneity of SVZ stem and progenitor cells underlines the necessity to develop methods for the accurate quantification of SVZ stem and progenitor subpopulations. In this study, we provide 3-dimensional topographical maps of slow cycling "stem" cells and progenitors based on their unique cell cycle properties. These maps revealed that both cell populations are present throughout the lateral ventricle wall as well as in discrete regions of the dorsal wall. Immunodetection of transcription factors expressed in defined progenitor populations further reveals that divergent lineages have clear regional enrichments in the rostro-caudal as well as in the dorso-ventral span of the lateral ventricle. Thus, progenitors expressing Tbr2 and Dlx2 were confined to dorsal and dorso-lateral regions of the lateral ventricle, respectively, while Mash1+ progenitors were more homogeneously distributed. All cell populations were enriched in the rostral-most region of the lateral ventricle. This diversity and uneven distribution greatly impede the accurate quantification of SVZ progenitor populations. This is illustrated by measuring the coefficient of error of estimates obtained by using increasing section sampling interval. Based on our empirical data, we provide such estimates for all progenitor populations investigated in this study. These can be used in future studies as guidelines to judge if the precision obtained with a sampling scheme is sufficient to detect statistically significant differences between experimental groups if a biological effect is present. Altogether, our study underlines the need to consider the SVZ of the lateral ventricle as a complex 3D structure and define methods to

  17. High-resolution passive sampling of dissolved methane in the water column of lakes in Greenland

    Science.gov (United States)

    Goldman, A. E.; Cadieux, S. B.; White, J. R.; Pratt, L. M.

    2013-12-01

    Arctic lakes are important participants in the global carbon cycle, releasing methane in a warming climate and contributing to a positive feedback to climate change. In order to yield detailed methane budgets and understand the implications of warming on methane dynamics, high-resolution profiles revealing methane behavior within the water column need to be obtained. Single day sampling using disruptive techniques has the potential to result in biases. In order to obtain high-resolution, undisturbed profiles of methane concentration and isotopic composition, this study evaluates a passive sampling method over a multi-day equilibration period. Selected for this study were two small lakes (Gatos Research Methane Carbon Isotope Analyzer. PDB sampling and pump sampling resulted in statistically similar concentrations (R2=0.89), ranging from 0.85 to 135 uM from PDB and 0.74 to 143 uM from pump sampling. In anoxic waters of the lake, where concentrations were high enough to yield robust isotopic results on the LGR MCIA, δ13C were also similar between the two methods, yielding -73‰ from PDB and -74‰ from pump sampling. Further investigation will produce results for a second lake and methane carbon and hydrogen isotopic composition for both lakes. Preliminary results for this passive sampling method are promising. We envision the use of this technique in future studies of dissolved methane and expect that it will provide a more finely resolved vertical profile, allowing for a more complete understanding of lacustrine methane dynamics.

  18. Genetic characterization of Toxoplasma gondii from Brazilian wildlife revealed abundant new genotypes

    Directory of Open Access Journals (Sweden)

    S.N. Vitaliano

    2014-12-01

    Full Text Available This study aimed to isolate and genotype T. gondii from Brazilian wildlife. For this purpose, 226 samples were submitted to mice bioassay and screened by PCR based on 18S rRNA sequences. A total of 15 T. gondii isolates were obtained, including samples from four armadillos (three Dasypus novemcinctus, one Euphractus sexcinctus, three collared anteaters (Tamandua tetradactyla, three whited-lipped peccaries (Tayassu pecari, one spotted paca (Cuniculus paca, one oncilla (Leopardus tigrinus, one hoary fox (Pseudalopex vetulus, one lineated woodpecker (Dryocopus lineatus and one maned wolf (Chrysocyon brachyurus. DNA from the isolates, originated from mice bioassay, and from the tissues of the wild animal, designated as “primary samples”, were genotyped by PCR–restriction fragment length polymorphism (PCR/RFLP, using 12 genetic markers (SAG1, SAG2, alt.SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L258, PK1, CS3 and Apico. A total of 17 genotypes were identified, with 13 identified for the first time and four already reported in published literature. Results herein obtained corroborate previous studies in Brazil, confirming high diversity and revealing unique genotypes in this region. Given most of genotypes here identified are different from previous studies in domestic animals, future studies on T. gondii from wildlife is of interest to understand population genetics and structure of this parasite.

  19. HICOSMO - cosmology with a complete sample of galaxy clusters - I. Data analysis, sample selection and luminosity-mass scaling relation

    Science.gov (United States)

    Schellenberger, G.; Reiprich, T. H.

    2017-08-01

    The X-ray regime, where the most massive visible component of galaxy clusters, the intracluster medium, is visible, offers directly measured quantities, like the luminosity, and derived quantities, like the total mass, to characterize these objects. The aim of this project is to analyse a complete sample of galaxy clusters in detail and constrain cosmological parameters, like the matter density, Ωm, or the amplitude of initial density fluctuations, σ8. The purely X-ray flux-limited sample (HIFLUGCS) consists of the 64 X-ray brightest galaxy clusters, which are excellent targets to study the systematic effects, that can bias results. We analysed in total 196 Chandra observations of the 64 HIFLUGCS clusters, with a total exposure time of 7.7 Ms. Here, we present our data analysis procedure (including an automated substructure detection and an energy band optimization for surface brightness profile analysis) that gives individually determined, robust total mass estimates. These masses are tested against dynamical and Planck Sunyaev-Zeldovich (SZ) derived masses of the same clusters, where good overall agreement is found with the dynamical masses. The Planck SZ masses seem to show a mass-dependent bias to our hydrostatic masses; possible biases in this mass-mass comparison are discussed including the Planck selection function. Furthermore, we show the results for the (0.1-2.4) keV luminosity versus mass scaling relation. The overall slope of the sample (1.34) is in agreement with expectations and values from literature. Splitting the sample into galaxy groups and clusters reveals, even after a selection bias correction, that galaxy groups exhibit a significantly steeper slope (1.88) compared to clusters (1.06).

  20. Detection of multidrug-resistant tuberculosis from stored DNA Samples: A multicenter study

    OpenAIRE

    Marie Sylvianne Rabodoarivelo; A Brandao; M C Cergole Novella; A G C. Bombonatte; B Imperiale; N Rakotosamimanana; N Morcillo; V Rasolofo; J C Palomino; A Martin

    2018-01-01

    Background: In low-income countries, rapid detection of tuberculosis (TB) drug resistance is often restricted by the difficulties of transporting and storing sputum samples from remote health centers to the reference laboratories where molecular tests are available. The aim of this study was to evaluate the performance of four transport and storage systems for molecular detection of rifampicin (RIF) and isoniazid (INH) resistance. Methods: This was a multicenter study. Molecular detection of ...

  1. Preliminary study on element mass fraction determination on catfish samples from Paraguay

    International Nuclear Information System (INIS)

    Moreira, Edson G.; Catharino, Marilia G.M.; Vasconcellos, Marina B.A.; Frutos, Sixto A.; Insaurralde, Mario S.

    2013-01-01

    South American catfish (Pseudoplatystoma), commonly known in Spanish as atigrado or surubi and in Portuguese as surubim or pintado is a large fish that typically reaches 1 m long and weighs 60 kg to 80 kg and may be found at the basins of the Amazon, the Sao Francisco and de la Plata rivers, usually in riverbeds and deep wells. Being a much appreciated fish for human consumption, it is quite sought after by fishermen who have been contributing to the reduction of the stocks. This fact attracted the attention of the Paraguayan authorities to the point of imposing restrictions to free fishing and commercialization. This study aims to assist the conservation efforts towards this fish by investigating its exposure to possible pollutants. Preliminary results on element determination on six samples of catfish from Paraguayan rivers are presented. Cs, Co, Fe, Se and Zn were determined by applying an Instrumental Neutron Activation Analysis method. While these element levels were lower than the legislation for human consumption, the elements As, Cr e La were not detected in the samples as they are below the detection limit of the method employed. Atomic Absorption Spectrometry was used to investigate the presence of Cd, Hg and Pb in the samples. Hg was detected in the samples while Cd and Pb were below the detection limit of the method. (author)

  2. Preliminary study on element mass fraction determination on catfish samples from Paraguay

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Edson G.; Catharino, Marilia G.M.; Vasconcellos, Marina B.A., E-mail: emoreira@ipen.br, E-mail: mbvascon@ipen.br, E-mail: mariliasemmler@uol.com.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Frutos, Sixto A.; Insaurralde, Mario S., E-mail: tony8013@hotmail.com, E-mail: insaurraldemar9@hotmail.com [Universidad Nacional de Asuncion (FCV/UNA), San Lorenzo (Paraguay). Facultad de Ciencias Veterinarias. Departamento de Pesca y Acuicultura

    2013-07-01

    South American catfish (Pseudoplatystoma), commonly known in Spanish as atigrado or surubi and in Portuguese as surubim or pintado is a large fish that typically reaches 1 m long and weighs 60 kg to 80 kg and may be found at the basins of the Amazon, the Sao Francisco and de la Plata rivers, usually in riverbeds and deep wells. Being a much appreciated fish for human consumption, it is quite sought after by fishermen who have been contributing to the reduction of the stocks. This fact attracted the attention of the Paraguayan authorities to the point of imposing restrictions to free fishing and commercialization. This study aims to assist the conservation efforts towards this fish by investigating its exposure to possible pollutants. Preliminary results on element determination on six samples of catfish from Paraguayan rivers are presented. Cs, Co, Fe, Se and Zn were determined by applying an Instrumental Neutron Activation Analysis method. While these element levels were lower than the legislation for human consumption, the elements As, Cr e La were not detected in the samples as they are below the detection limit of the method employed. Atomic Absorption Spectrometry was used to investigate the presence of Cd, Hg and Pb in the samples. Hg was detected in the samples while Cd and Pb were below the detection limit of the method. (author)

  3. MicroRNA Expression in Laser Micro-dissected Breast Cancer Tissue Samples - a Pilot Study.

    Science.gov (United States)

    Seclaman, Edward; Narita, Diana; Anghel, Andrei; Cireap, Natalia; Ilina, Razvan; Sirbu, Ioan Ovidiu; Marian, Catalin

    2017-10-28

    Breast cancer continues to represent a significant public health burden despite outstanding research advances regarding the molecular mechanisms of cancer biology, biomarkers for diagnostics and prognostic and therapeutic management of this disease. The studies of micro RNAs in breast cancer have underlined their potential as biomarkers and therapeutic targets; however most of these studies are still done on largely heterogeneous whole breast tissue samples. In this pilot study we have investigated the expression of four micro RNAs (miR-21, 145, 155, 92) known to be involved in breast cancer, in homogenous cell populations collected by laser capture microdissection from breast tissue section slides. Micro RNA expression was assessed by real time PCR, and associations with clinical and pathological characteristics were also explored. Our results have confirmed previous associations of miR-21 expression with poor prognosis characteristics of breast cancers such as high stage, large and highly proliferative tumors. No statistically significant associations were found with the other micro RNAs investigated, possibly due to the small sample size of our study. Our results also suggest that miR-484 could be a suitable endogenous control for data normalization in breast tissues, these results needing further confirmation by future studies. In summary, our pilot study showed the feasibility of detecting micro RNAs expression in homogenous laser captured microdissected invasive breast cancer samples, and confirmed some of the previously reported associations with poor prognostic characteristics of breast tumors.

  4. Self-sampling kits to increase HIV testing among black Africans in the UK: the HAUS mixed-methods study.

    Science.gov (United States)

    Seguin, Maureen; Dodds, Catherine; Mugweni, Esther; McDaid, Lisa; Flowers, Paul; Wayal, Sonali; Zomer, Ella; Weatherburn, Peter; Fakoya, Ibidun; Hartney, Thomas; McDonagh, Lorraine; Hunter, Rachael; Young, Ingrid; Khan, Shabana; Freemantle, Nick; Chwaula, Jabulani; Sachikonye, Memory; Anderson, Jane; Singh, Surinder; Nastouli, Eleni; Rait, Greta; Burns, Fiona

    2018-04-01

    Timely diagnosis of human immunodeficiency virus (HIV) enables access to antiretroviral treatment, which reduces mortality, morbidity and further transmission in people living with HIV. In the UK, late diagnosis among black African people persists. Novel methods to enhance HIV testing in this population are needed. To develop a self-sampling kit (SSK) intervention to increase HIV testing among black Africans, using existing community and health-care settings (stage 1) and to assess the feasibility for a Phase III evaluation (stage 2). A two-stage, mixed-methods design. Stage 1 involved a systematic literature review, focus groups and interviews with key stakeholders and black Africans. Data obtained provided the theoretical base for intervention development and operationalisation. Stage 2 was a prospective, non-randomised study of a provider-initiated, HIV SSK distribution intervention targeted at black Africans. The intervention was assessed for cost-effectiveness. A process evaluation explored feasibility, acceptability and fidelity. Twelve general practices and three community settings in London. HIV SSK return rate. Stage 1 - the systematic review revealed support for HIV SSKs, but with scant evidence on their use and clinical effectiveness among black Africans. Although the qualitative findings supported SSK distribution in settings already used by black Africans, concerns were raised about the complexity of the SSK and the acceptability of targeting. These findings were used to develop a theoretically informed intervention. Stage 2 - of the 349 eligible people approached, 125 (35.8%) agreed to participate. Data from 119 were included in the analysis; 54.5% (65/119) of those who took a kit returned a sample; 83.1% of tests returned were HIV negative; and 16.9% were not processed, because of insufficient samples. Process evaluation showed the time pressures of the research process to be a significant barrier to feasibility. Other major barriers were

  5. Stability of measures from children's interviews: the effects of time, sample length, and topic.

    Science.gov (United States)

    Heilmann, John; DeBrock, Lindsay; Riley-Tillman, T Chris

    2013-08-01

    The purpose of this study was to examine the reliability of, and sources of variability in, language measures from interviews collected from young school-age children. Two 10-min interviews were collected from 20 at-risk kindergarten children by an examiner using a standardized set of questions. Test-retest reliability coefficients were calculated for 8 language measures. Generalizability theory (G-theory) analyses were completed to document the variability introduced into the measures from the child, session, sample length, and topic. Significant and strong reliability correlation coefficients were observed for most of the language sample measures. The G-theory analyses revealed that most of the variance in the language measures was attributed to the child. Session, sample length, and topic accounted for negligible amounts of variance in most of the language measures. Measures from interviews were reliable across sessions, and the sample length and topic did not have a substantial impact on the reliability of the language measures. Implications regarding the clinical feasibility of language sample analysis for assessment and progress monitoring are discussed.

  6. Contaminant Gradients in Trees: Directional Tree Coring Reveals Boundaries of Soil and Soil-Gas Contamination with Potential Applications in Vapor Intrusion Assessment.

    Science.gov (United States)

    Wilson, Jordan L; Samaranayake, V A; Limmer, Matthew A; Schumacher, John G; Burken, Joel G

    2017-12-19

    Contaminated sites pose ecological and human-health risks through exposure to contaminated soil and groundwater. Whereas we can readily locate, monitor, and track contaminants in groundwater, it is harder to perform these tasks in the vadose zone. In this study, tree-core samples were collected at a Superfund site to determine if the sample-collection location around a particular tree could reveal the subsurface location, or direction, of soil and soil-gas contaminant plumes. Contaminant-centroid vectors were calculated from tree-core data to reveal contaminant distributions in directional tree samples at a higher resolution, and vectors were correlated with soil-gas characterization collected using conventional methods. Results clearly demonstrated that directional tree coring around tree trunks can indicate gradients in soil and soil-gas contaminant plumes, and the strength of the correlations were directly proportionate to the magnitude of tree-core concentration gradients (spearman's coefficient of -0.61 and -0.55 in soil and tree-core gradients, respectively). Linear regression indicates agreement between the concentration-centroid vectors is significantly affected by in planta and soil concentration gradients and when concentration centroids in soil are closer to trees. Given the existing link between soil-gas and vapor intrusion, this study also indicates that directional tree coring might be applicable in vapor intrusion assessment.

  7. Analysis of small sample size studies using nonparametric bootstrap test with pooled resampling method.

    Science.gov (United States)

    Dwivedi, Alok Kumar; Mallawaarachchi, Indika; Alvarado, Luis A

    2017-06-30

    Experimental studies in biomedical research frequently pose analytical problems related to small sample size. In such studies, there are conflicting findings regarding the choice of parametric and nonparametric analysis, especially with non-normal data. In such instances, some methodologists questioned the validity of parametric tests and suggested nonparametric tests. In contrast, other methodologists found nonparametric tests to be too conservative and less powerful and thus preferred using parametric tests. Some researchers have recommended using a bootstrap test; however, this method also has small sample size limitation. We used a pooled method in nonparametric bootstrap test that may overcome the problem related with small samples in hypothesis testing. The present study compared nonparametric bootstrap test with pooled resampling method corresponding to parametric, nonparametric, and permutation tests through extensive simulations under various conditions and using real data examples. The nonparametric pooled bootstrap t-test provided equal or greater power for comparing two means as compared with unpaired t-test, Welch t-test, Wilcoxon rank sum test, and permutation test while maintaining type I error probability for any conditions except for Cauchy and extreme variable lognormal distributions. In such cases, we suggest using an exact Wilcoxon rank sum test. Nonparametric bootstrap paired t-test also provided better performance than other alternatives. Nonparametric bootstrap test provided benefit over exact Kruskal-Wallis test. We suggest using nonparametric bootstrap test with pooled resampling method for comparing paired or unpaired means and for validating the one way analysis of variance test results for non-normal data in small sample size studies. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  8. A novel approach for small sample size family-based association studies: sequential tests.

    Science.gov (United States)

    Ilk, Ozlem; Rajabli, Farid; Dungul, Dilay Ciglidag; Ozdag, Hilal; Ilk, Hakki Gokhan

    2011-08-01

    In this paper, we propose a sequential probability ratio test (SPRT) to overcome the problem of limited samples in studies related to complex genetic diseases. The results of this novel approach are compared with the ones obtained from the traditional transmission disequilibrium test (TDT) on simulated data. Although TDT classifies single-nucleotide polymorphisms (SNPs) to only two groups (SNPs associated with the disease and the others), SPRT has the flexibility of assigning SNPs to a third group, that is, those for which we do not have enough evidence and should keep sampling. It is shown that SPRT results in smaller ratios of false positives and negatives, as well as better accuracy and sensitivity values for classifying SNPs when compared with TDT. By using SPRT, data with small sample size become usable for an accurate association analysis.

  9. Blood sampling and hemolysis affect concentration of plasma metabolites

    DEFF Research Database (Denmark)

    Theil, Peter Kappel; Pedersen, Lene Juul; Jensen, Margit Bak

    2012-01-01

    design and blood was collected after restraint via vein puncture 1, 4, 11, and 23 h after morning feeding. Plasma samples were categorized as without or with minor or major hemolysis [clear (n = 218), yellow (n = 97), or red (n = 37)] upon centrifugation. Plasma NEFA (P ...Two experiments were carried out to reveal and quantify plasma metabolites that are sensitive to hemolysis and animal stress due to the blood sampling procedure (vein puncture vs. catheter). In Exp. 1, 48 sows were fed 4 diets either once (0800 h) or twice daily (0800 h and 1500 h) in a crossover......, a subset of samples from 24 sows fed twice daily in Exp. 1 was combined with data obtained from 30 sows sampled using jugular vein catheters. All sows in Exp. 2 were fed twice daily (0800 h and 1500 h) and blood samples collected repeatedly 1, 4, 11, and 23 h after morning feeding (other conditions were...

  10. Microbial and chemical analysis of illicit drugs samples confiscated from different areas of PakistanMicrobial and chemical analysis of illicit drugs samples confiscated from different areas of Pakistan.

    Science.gov (United States)

    Hussain, Shahzad; Khattak, Zainab; Mahmood, Sidra; Malik, Farnaz; Riaz, Humayun; Raza, Syed Atif; Khan, Samiullah

    2016-09-01

    The microbial and chemical analysis of illicit drug samples from different areas of Pakistan i.e. Quetta, Karachi, Lahore and Islamabad was conducted in a cross-sectional study at National Institute of Health, Islamabad. The drug samples were confiscated by Anti Narcotics Force (ANF), Pakistan. Microbial analysis was done by estimating bioburden which revealed the presence of gram negative and positive bacteria's, fungus, Streptococcus, Staphylococcus species. Trypton soya agar was used for total aerobic count, MacConkey agar for gram-negative bacteria, Sabouraud dextrose agar for fungus and Vogel-Johnson agar for Streptococcus and Staphylococcus species. Colour tests were applied to identify the drug samples. Qualitative and quantitative analysis of suspected samples of Heroin, morphine, cocaine and acetic anhydride was made by employing different chromatographic techniques i.e. Thin-layer chromatography (TLC) and High-performance liquid chromatography (HPLC). The samples were found to be adulterated with paracetamol, diazepam and Dextromethorphen. Acetic anhydride was adulterated with hydrochloric acid (HCl). There is lack of information providing structured advice on responses to the consequences of illicit drug adulteration. Robust and rehearsed interventions and communication strategies would provide a basis for response for a wide variety of organisations. Research into the usefulness of media warnings about adulteration of illicit drugs is required.

  11. Social Anhedonia and Schizotypy in a Community Sample: The Maryland Longitudinal Study of Schizotypy

    Science.gov (United States)

    Blanchard, Jack J.; Collins, Lindsay M.; Aghevli, Minu; Leung, Winnie W.; Cohen, Alex S.

    2011-01-01

    Social anhedonia has been employed in psychometric high-risk studies to identify putative schizotypes. To date, this research has focused almost exclusively on college samples. The current study sought to examine the validity of social anhedonia as an indicator of risk for schizophrenia-spectrum disorders within a community sample. Furthermore, we evaluated the role of other individual difference variables in accounting for variable clinical severity within the social anhedonia group including trait affectivity, social support, and family environment. Following the mailed questionnaire screening of 2434 eighteen-year olds, laboratory assessments were conducted with individuals identified as being high in social anhedonia (n = 86) and a comparison sample (n = 89). Compared with the control group, individuals in the social anhedonia group were found to have higher rates of mood disorders, elevated schizophrenia-spectrum personality disorder characteristics, greater negative symptom characteristics, and lower global functioning. Individuals within the social anhedonia group also reported greater trait negative affectivity, lower positive affectivity, less social support, and more family conflict. Low social support and problematic family environment were found to be related to elevations in spectrum personality disorder characteristics and poorer functioning within the social anhedonia group. These cross-sectional findings from a community sample provide further support for social anhedonia as a possible indicator of schizotypy. PMID:19850669

  12. Diversity of the Tetracycline Mobilome within a Chinese Pig Manure Sample.

    Science.gov (United States)

    Leclercq, Sébastien Olivier; Wang, Chao; Zhu, Yaxin; Wu, Hai; Du, Xiaochen; Liu, Zhipei; Feng, Jie

    2016-11-01

    Tetracycline antibiotics are widely used in livestock, and tetracycline resistance genes (TRG) are frequently reported in the manure of farmed animals. However, the diversity of TRG-carrying transposons in manure has still been rarely investigated. Using a culture-free functional metagenomic procedure, combined with large-insert library construction and sequencing, bioinformatic analyses, and functional experiments, we identified 17 distinct TRGs in a single pig manure sample, including two new tet genes: tet(59), encoding a tetracycline efflux pump, and tet(W/N/W), encoding mosaic ribosomal protection. Our study also revealed six new TRG-carrying putative nonconjugative transposons: Tn5706-like transposon Tn6298, IS200/605-related transposon Tn6303, Tn3 family transposon Tn6299, and three ISCR2-related transposons, Tn62300, Tn62301, and Tn62302 IMPORTANCE: Fertilization of agricultural fields with animal manure is believed to play a major role in antibiotic resistance dissemination in the environment. There is growing concern for the possible spread of antibiotic resistance from the environment to humans since genetic resistance determinants may be located in transposons and other mobile genetic elements potentially transferable to pathogens. Among the various antibiotic resistance genes found in manure, tetracycline resistance genes (TRGs) are some of the most common. The present study provides a detailed snapshot of the tetracycline mobilome in a single pig manure sample, revealing an unappreciated diversity of TRGs and potential TRG mobility vectors. Our precise identification of the TRG-carrying units will enable us to investigate in more details their mobility effectiveness. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  13. Internalized Homophobia and Perceived Stigma: A Validation Study of Stigma Measures in a Sample of Young Men who Have Sex with Men.

    Science.gov (United States)

    Puckett, Jae A; Newcomb, Michael E; Ryan, Daniel T; Swann, Greg; Garofalo, Robert; Mustanski, Brian

    2017-03-01

    Young men who have sex with men (YMSM) experience minority stressors that impact their mental health, substance use, and sexual risk behaviors. Internalized homophobia (IH) and perceived stigma represent two of these minority stressors, and there has been limited research empirically validating measures of these constructs. We validated measures of IH and perceived stigma with a sample of 450 YMSM (mean age=18.9) and a sample of 370 YMSM (mean age=22.9). Results from exploratory and confirmatory factor analyses supported modifications to the IH and perceived stigma scales, ultimately revealing a three factor and one factor structure, respectively. Convergent and discriminant validity were examined utilizing correlations between IH, perceived stigma, and other variables related to minority stress (e.g., victimization). We evaluated predictive validity by examining relations with mental health, substance use, and risky sexual behaviors measured 12-months from baseline. There were mixed findings for IH, with subscales varying in their relations to mental health, drinking, and sexual risk variables. Perceived stigma was not related to mental health or substance use, but was associated with greater prevalence of STIs. Findings supported the use of these modified scales with YMSM and highlight the need for further measurement studies.

  14. Differential Mobility-Mass Spectrometry Double Spike Isotope Dilution Study of Release of β-Methylaminoalanine and Proteinogenic Amino Acids during Biological Sample Hydrolysis.

    Science.gov (United States)

    Beach, Daniel G; Kerrin, Elliott S; Giddings, Sabrina D; Quilliam, Michael A; McCarron, Pearse

    2018-01-08

    The non-protein amino acid β-methylamino-L-alanine (BMAA) has been linked to neurodegenerative disease and reported throughout the environment. Proposed mechanisms of bioaccumulation, trophic transfer and chronic toxicity of BMAA rely on the hypothesis of protein misincorporation. Poorly selective methods for BMAA analysis have led to controversy. Here, a recently reported highly selective method for BMAA quantitation using hydrophilic interaction liquid chromatography-differential mobility spectrometry-tandem mass spectrometry (HILIC-DMS-MS/MS) is expanded to include proteinogenic amino acids from hydrolyzed biological samples. For BMAA quantitation, we present a double spiking isotope dilution approach using D 3 -BMAA and 13 C 15 N 2 -BMAA. These methods were applied to study release of BMAA during acid hydrolysis under a variety of conditions, revealing that the majority of BMAA can be extracted along with only a small proportion of protein. A time course hydrolysis of BMAA from mussel tissue was carried out to assess the recovery of BMAA during sample preparation. The majority of BMAA measured by typical methods was released before a significant proportion of protein was hydrolyzed. Little change was observed in protein hydrolysis beyond typical hydrolysis times but the concentration of BMAA increased linearly. These findings demonstrate protein misincorporation is not the predominant form of BMAA in cycad and shellfish.

  15. Improved orientation sampling for indexing diffraction patterns of polycrystalline materials

    DEFF Research Database (Denmark)

    Larsen, Peter Mahler; Schmidt, Søren

    2017-01-01

    to that of optimally distributing points on a four‐dimensional sphere. In doing so, the number of orientation samples needed to achieve a desired indexing accuracy is significantly reduced. Orientation sets at a range of sizes are generated in this way for all Laue groups and are made available online for easy use.......Orientation mapping is a widely used technique for revealing the microstructure of a polycrystalline sample. The crystalline orientation at each point in the sample is determined by analysis of the diffraction pattern, a process known as pattern indexing. A recent development in pattern indexing...... in the presence of noise, it has very high computational requirements. In this article, the computational burden is reduced by developing a method for nearly optimal sampling of orientations. By using the quaternion representation of orientations, it is shown that the optimal sampling problem is equivalent...

  16. Cooling tower wood sampling and analyses: A case study

    International Nuclear Information System (INIS)

    Haymore, J.L.

    1985-01-01

    Extensive wood sampling and analyses programs were initiated on crossflow and counterflow cooling towers that have been in service since 1951 and 1955, respectively. Wood samples were taken from all areas of the towers and were subjected to biological, chemical and physical tests. The tests and results for the analyses are discussed. The results indicate the degree of wood deterioration, and areas of the towers which experience the most advanced degree of degradation

  17. Handsome wants as handsome does: physical attractiveness and gender differences in revealed sexual preferences.

    Science.gov (United States)

    McClintock, Elizabeth Aura

    2011-01-01

    In this article I evaluate the effect of physical attractiveness on young adults' sexual and romantic outcomes to reveal gender differences in acted preferences. Using data from the National Longitudinal Study of Adolescent Health (Add Health), a probability sample of young adults (n = 14,276), I investigate gender differences in desired sexual partner accumulation, relationship status, and timing of sexual intercourse. I find gender differences in sexual and romantic strategies consistent with those predicted by the double standard of sexuality and evolutionary theory. Specifically, compared to men, women pursue more committed relationships, fewer sexual partners, and delayed sexual intercourse.

  18. A short version of the revised 'experience of close relationships questionnaire': investigating non-clinical and clinical samples.

    Science.gov (United States)

    Wongpakaran, Tinakon; Wongpakaran, Nahathai

    2012-01-01

    This study seeks to investigate the psychometric properties of the short version of the revised 'Experience of Close Relationships' questionnaire, comparing non-clinical and clinical samples. In total 702 subjects participated in this study, of whom 531 were non-clinical participants and 171 were psychiatric patients. They completed the short version of the revised 'Experience of Close Relationships' questionnaire (ECR-R-18), the Perceived Stress Scale-10(PSS-10), the Rosenberg Self-Esteem Scale (RSES) and the UCLA Loneliness scale. A retest of the ECR-R-18 was then performed at four-week intervals. Then, confirmatory factor analyses were performed to test the validity of the new scale. The ECR-R-18 showed a fair to good internal consistency (α 0.77 to 0.87) for both samples, and the test-retest reliability was found to be satisfactory (ICC = 0.75). The anxiety sub-scale demonstrated concurrent validity with PSS-10 and RSES, while the avoidance sub-scale showed concurrent validity with the UCLA Loneliness Scale. Confirmatory factor analysis using method factors yielded two factors with an acceptable model fit for both groups. An invariance test revealed that the ECR-R-18 when used on the clinical group differed from when used with the non-clinical group. The ECR-R-18 questionnaire revealed an overall better level of fit than the original 36 item questionnaire, indicating its suitability for use with a broader group of samples, including clinical samples. The reliability of the ECR-R- 18 might be increased if a modified scoring system is used and if our suggestions with regard to future studies are followed up.

  19. Structural, Geochemical, and Isotopic Studies on Magmatic Dyke Swarms of the South Shetland Islands Volcanic Arc, West Antarctica - Revealing the Geodynamic History

    Science.gov (United States)

    Kraus, S.; Miller, H.

    2003-12-01

    Between 2000 and 2002 areas of up to 100,000 m2 have been mapped at several locations of the South Shetland Islands, mainly on King George and Livingston Islands. A structural analysis of the dykes and the host rocks was undertaken, and about 250 dykes were sampled for geochemical studies. On Livingston Island six different strike directions were identified, yielding a reliable relative time sequence as deduced from field-relationships. Geochemically, these dykes can be separated into five different groups, correlating with the different strike directions, one of those groups comprising two directions. Analysis of the structural data shows, that at least on Livingston Island only minor changes of the tensional situation occurred. Geochemical data reveal that all dykes of the South Shetland Islands belong to a calc-alkaline, arc-related suite, ranging from primitive basalts to highly differentiated rhyolites. Interpretation of Sr isotopic data of the dykes proves difficult, as there are indications for sea-water induced Sr-alteration. Nd isotopic analysis yield better results, revealing a three-stage development from the oldest dykes (ɛ Nd -0.2 to 0.6) on Livingston Island towards a second, younger group (ɛ Nd 2.8 to 4.2, also Livingston), terminating with a third one (ɛ Nd 5.2 to 7.6), which includes the youngest dykes on Livingston and all dykes on King George and also Penguin Island. Either two mantle sources were involved, or the amount of crustal contamination changed considerately with time. It may have been high during initial arc volcanism, because of a still unstretched crust, then decreasing continually with progressing volcanism. In any case, the pattern reflects a chronological sequence corresponding with other authors' hypothesis of a migrating arc volcanism from SW to NE, i.e. from Livingston (older dykes) towards King George Island (younger dykes). Pb isotopic data, plottet together with MORB- and sediment-samples dredged from the Drake Passage

  20. Novel multiplex PCR reveals multiple trypanosomatid species infecting North American bumble bees (Hymenoptera: Apidae: Bombus).

    Science.gov (United States)

    Tripodi, Amber D; Szalanski, Allen L; Strange, James P

    2018-03-01

    Crithidia bombi and Crithidia expoeki (Trypanosomatidae) are common parasites of bumble bees (Bombus spp.). Crithidia bombi was described in the 1980s, and C. expoeki was recently discovered using molecular tools. Both species have cosmopolitan distributions among their bumble bee hosts, but there have been few bumble bee studies that have identified infections to species since the original description of C. expoeki in 2010. Morphological identification of species is difficult due to variability within each stage of their complex lifecycles, although they can be easily differentiated through DNA sequencing. However, DNA sequencing can be expensive, particularly with many samples to diagnose. In order to reliably and inexpensively distinguish Crithidia species for a large-scale survey, we developed a multiplex PCR protocol using species-specific primers with a universal trypanosomatid primer set to detect unexpected relatives. We applied this method to 356 trypanosomatid-positive bumble bees from North America as a first-look at the distribution and host range of each parasite in the region. Crithidia bombi was more common (90.2%) than C. expoeki (21.3%), with most C. expoeki-positive samples existing as co-infections with C. bombi (13.8%). This two-step detection method also revealed that 2.2% samples were positive for trypanosmatids that were neither C. bombi nor C. expoeki. Sequencing revealed that two individuals were positive for C. mellificae, one for Lotmaria passim, and three for two unclassified trypanosomatids. This two-step method is effective in diagnosing known bumble bee infecting Crithidia species, and allowing for the discovery of unknown potential symbionts. Published by Elsevier Inc.

  1. Paleoparasitological remains revealed by seven historic contexts from "Place d'Armes", Namur, Belgium

    Directory of Open Access Journals (Sweden)

    Gino Chaves da Rocha

    2006-12-01

    Full Text Available Human occupation for several centuries was recorded in the archaeological layers of "Place d'Armes", Namur, Belgium. Preventive archaeological excavations were carried out between 1996/1997 and seven historical strata were observed, from Gallo-Roman period up to Modern Times. Soil samples from cesspools, latrines, and structures-like were studied and revealed intestinal parasite eggs in the different archaeological contexts. Ascaris lumbricoides, A. suum, Trichuris trichiura, T. suis. Taenia sp., Fasciola hepatica, Diphyllobothrium sp., Capillaria sp. and Oxyuris equi eggs were found. Paleoparasitology confirmed the use of structures as latrines or cesspit as firstly supposed by the archaeologists. Medieval latrines were not only used for rejection of human excrements. The finding of Ascaris sp. and Trichuris sp. eggs may point to human's or wild swine's feces. Gallo-Roman people used to eat wild boar. Therefore, both A. suum and T. suis, or A. lumbricoides and T. trichuris, may be present, considering a swine carcass recovered into a cesspit. Careful sediment analysis may reveal its origin, although parasites of domestic animals can be found together with those of human's. Taenia sp. eggs identified in latrine samples indicate ingestion of uncooked beef with cysticercoid larvae. F. hepatica eggs suggest the ingestion of raw contaminated vegetables and Diphyllobothrium sp. eggs indicate contaminated fresh-water fish consumption. Ascaris sp. and Trichuris sp. eggs indicate fecal-oral infection by human and/or animal excrements.

  2. Impact of shrinking measurement error budgets on qualification metrology sampling and cost

    Science.gov (United States)

    Sendelbach, Matthew; Sarig, Niv; Wakamoto, Koichi; Kim, Hyang Kyun (Helen); Isbester, Paul; Asano, Masafumi; Matsuki, Kazuto; Vaid, Alok; Osorio, Carmen; Archie, Chas

    2014-04-01

    When designing an experiment to assess the accuracy of a tool as compared to a reference tool, semiconductor metrologists are often confronted with the situation that they must decide on the sampling strategy before the measurements begin. This decision is usually based largely on the previous experience of the metrologist and the available resources, and not on the statistics that are needed to achieve acceptable confidence limits on the final result. This paper shows a solution to this problem, called inverse TMU analysis, by presenting statistically-based equations that allow the user to estimate the needed sampling after providing appropriate inputs, allowing him to make important "risk vs. reward" sampling, cost, and equipment decisions. Application examples using experimental data from scatterometry and critical dimension scanning electron microscope (CD-SEM) tools are used first to demonstrate how the inverse TMU analysis methodology can be used to make intelligent sampling decisions before the start of the experiment, and then to reveal why low sampling can lead to unstable and misleading results. A model is developed that can help an experimenter minimize the costs associated both with increased sampling and with making wrong decisions caused by insufficient sampling. A second cost model is described that reveals the inadequacy of current TEM (Transmission Electron Microscopy) sampling practices and the enormous costs associated with TEM sampling that is needed to provide reasonable levels of certainty in the result. These high costs reach into the tens of millions of dollars for TEM reference metrology as the measurement error budgets reach angstrom levels. The paper concludes with strategies on how to manage and mitigate these costs.

  3. Isotopic studies of rare gases in terrestrial samples and in natural nucleosynthesis

    International Nuclear Information System (INIS)

    Reynolds, J.H.

    1988-08-01

    This project is concerned with research in rare gas mass spectrometry. The broad objective is to read the natural record that isotopes of the rare gases comprise as trace constituents of natural gases, rocks, and meteorites. In past years, these interests have led to the study of such diverse problems as the dating of rocks, the early chronology and isotopic structure of the solar system as revealed by extinct radioactivities, and the elemental and isotopic composition of trapped primordial rare gases in meteorites. In recent years, the project has focused progressively more on terrestrial problems

  4. Isotopic studies of rare gases in terrestrial samples and in natural nucleosynthesis

    International Nuclear Information System (INIS)

    1987-07-01

    This project is concerned with research in rare gas mass spectrometry. The broad objective is to read the natural record that isotopes of the rare gases comprise as trace constituents of natural gases, rocks, and meteorites. In past years, these interests have led to the study of such diverse problems as the dating of rocks, the early chronology and isotopic structure of the solar system as revealed by extinct radioactivities, and the elemental and isotopic composition of trapped primordial rare gases in meteorites. In recent years, the project has focused progressively more on terrestrial problems

  5. A Preliminary Study on Sensitivity and Uncertainty Analysis with Statistic Method: Uncertainty Analysis with Cross Section Sampling from Lognormal Distribution

    Energy Technology Data Exchange (ETDEWEB)

    Song, Myung Sub; Kim, Song Hyun; Kim, Jong Kyung [Hanyang Univ., Seoul (Korea, Republic of); Noh, Jae Man [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    The uncertainty evaluation with statistical method is performed by repetition of transport calculation with sampling the directly perturbed nuclear data. Hence, the reliable uncertainty result can be obtained by analyzing the results of the numerous transport calculations. One of the problems in the uncertainty analysis with the statistical approach is known as that the cross section sampling from the normal (Gaussian) distribution with relatively large standard deviation leads to the sampling error of the cross sections such as the sampling of the negative cross section. Some collection methods are noted; however, the methods can distort the distribution of the sampled cross sections. In this study, a sampling method of the nuclear data is proposed by using lognormal distribution. After that, the criticality calculations with sampled nuclear data are performed and the results are compared with that from the normal distribution which is conventionally used in the previous studies. In this study, the statistical sampling method of the cross section with the lognormal distribution was proposed to increase the sampling accuracy without negative sampling error. Also, a stochastic cross section sampling and writing program was developed. For the sensitivity and uncertainty analysis, the cross section sampling was pursued with the normal and lognormal distribution. The uncertainties, which are caused by covariance of (n,.) cross sections, were evaluated by solving GODIVA problem. The results show that the sampling method with lognormal distribution can efficiently solve the negative sampling problem referred in the previous studies. It is expected that this study will contribute to increase the accuracy of the sampling-based uncertainty analysis.

  6. A Preliminary Study on Sensitivity and Uncertainty Analysis with Statistic Method: Uncertainty Analysis with Cross Section Sampling from Lognormal Distribution

    International Nuclear Information System (INIS)

    Song, Myung Sub; Kim, Song Hyun; Kim, Jong Kyung; Noh, Jae Man

    2013-01-01

    The uncertainty evaluation with statistical method is performed by repetition of transport calculation with sampling the directly perturbed nuclear data. Hence, the reliable uncertainty result can be obtained by analyzing the results of the numerous transport calculations. One of the problems in the uncertainty analysis with the statistical approach is known as that the cross section sampling from the normal (Gaussian) distribution with relatively large standard deviation leads to the sampling error of the cross sections such as the sampling of the negative cross section. Some collection methods are noted; however, the methods can distort the distribution of the sampled cross sections. In this study, a sampling method of the nuclear data is proposed by using lognormal distribution. After that, the criticality calculations with sampled nuclear data are performed and the results are compared with that from the normal distribution which is conventionally used in the previous studies. In this study, the statistical sampling method of the cross section with the lognormal distribution was proposed to increase the sampling accuracy without negative sampling error. Also, a stochastic cross section sampling and writing program was developed. For the sensitivity and uncertainty analysis, the cross section sampling was pursued with the normal and lognormal distribution. The uncertainties, which are caused by covariance of (n,.) cross sections, were evaluated by solving GODIVA problem. The results show that the sampling method with lognormal distribution can efficiently solve the negative sampling problem referred in the previous studies. It is expected that this study will contribute to increase the accuracy of the sampling-based uncertainty analysis

  7. Three-year-olds obey the sample size principle of induction: the influence of evidence presentation and sample size disparity on young children's generalizations.

    Science.gov (United States)

    Lawson, Chris A

    2014-07-01

    Three experiments with 81 3-year-olds (M=3.62years) examined the conditions that enable young children to use the sample size principle (SSP) of induction-the inductive rule that facilitates generalizations from large rather than small samples of evidence. In Experiment 1, children exhibited the SSP when exemplars were presented sequentially but not when exemplars were presented simultaneously. Results from Experiment 3 suggest that the advantage of sequential presentation is not due to the additional time to process the available input from the two samples but instead may be linked to better memory for specific individuals in the large sample. In addition, findings from Experiments 1 and 2 suggest that adherence to the SSP is mediated by the disparity between presented samples. Overall, these results reveal that the SSP appears early in development and is guided by basic cognitive processes triggered during the acquisition of input. Copyright © 2013 Elsevier Inc. All rights reserved.

  8. Accuracy of micro four-point probe measurements on inhomogeneous samples: A probe spacing dependence study

    DEFF Research Database (Denmark)

    Wang, Fei; Petersen, Dirch Hjorth; Østerberg, Frederik Westergaard

    2009-01-01

    In this paper, we discuss a probe spacing dependence study in order to estimate the accuracy of micro four-point probe measurements on inhomogeneous samples. Based on sensitivity calculations, both sheet resistance and Hall effect measurements are studied for samples (e.g. laser annealed samples...... the probe spacing is smaller than 1/40 of the variation wavelength, micro four-point probes can provide an accurate record of local properties with less than 1% measurement error. All the calculations agree well with previous experimental results.......) with periodic variations of sheet resistance, sheet carrier density, and carrier mobility. With a variation wavelength of ¿, probe spacings from 0.0012 to 1002 have been applied to characterize the local variations. The calculations show that the measurement error is highly dependent on the probe spacing. When...

  9. Characterization of acid-base properties of two gibbsite samples in the context of literature results.

    Science.gov (United States)

    Adekola, F; Fédoroff, M; Geckeis, H; Kupcik, T; Lefèvre, G; Lützenkirchen, J; Plaschke, M; Preocanin, T; Rabung, T; Schild, D

    2011-02-01

    Two different gibbsites, one commercial and one synthesized according to a frequently applied recipe, were studied in an interlaboratory attempt to gain insight into the origin of widely differing reports on gibbsite acid-base surface properties. In addition to a thorough characterization of the two solids, several methods relevant to the interfacial charging were applied to the two samples: potentiometric titrations to obtain the "apparent" proton related surface charge density, zeta-potential measurements characterizing the potential at the plane of shear, and Attenuated Total Reflection Infrared Spectroscopy (ATR-IR) to obtain information on the variation of counter-ion adsorption with pH (using nitrate as a probe). Values of the IEP at 9-10 and 11.2-11.3 were found for the commercial and synthesized sample, respectively. The experimental observations revealed huge differences in the charging behavior between the two samples. Such differences also appeared in the titration kinetics. A detailed literature review revealed similar disparity with no apparent systematic trend. While previously the waiting time between additions had been advocated to explain such differences among synthesized samples, our results do not support such a conclusion. Instead, we find that the amount of titrant added in each aliquot appears to have a significant influence on the titration curves. While we can relate a number of observations to others, a number of open questions and contradictions remain. We suggest various processes, which can explain the observed behavior. Copyright © 2010 Elsevier Inc. All rights reserved.

  10. Reveal genes functionally associated with ACADS by a network study.

    Science.gov (United States)

    Chen, Yulong; Su, Zhiguang

    2015-09-15

    Establishing a systematic network is aimed at finding essential human gene-gene/gene-disease pathway by means of network inter-connecting patterns and functional annotation analysis. In the present study, we have analyzed functional gene interactions of short-chain acyl-coenzyme A dehydrogenase gene (ACADS). ACADS plays a vital role in free fatty acid β-oxidation and regulates energy homeostasis. Modules of highly inter-connected genes in disease-specific ACADS network are derived by integrating gene function and protein interaction data. Among the 8 genes in ACADS web retrieved from both STRING and GeneMANIA, ACADS is effectively conjoined with 4 genes including HAHDA, HADHB, ECHS1 and ACAT1. The functional analysis is done via ontological briefing and candidate disease identification. We observed that the highly efficient-interlinked genes connected with ACADS are HAHDA, HADHB, ECHS1 and ACAT1. Interestingly, the ontological aspect of genes in the ACADS network reveals that ACADS, HAHDA and HADHB play equally vital roles in fatty acid metabolism. The gene ACAT1 together with ACADS indulges in ketone metabolism. Our computational gene web analysis also predicts potential candidate disease recognition, thus indicating the involvement of ACADS, HAHDA, HADHB, ECHS1 and ACAT1 not only with lipid metabolism but also with infant death syndrome, skeletal myopathy, acute hepatic encephalopathy, Reye-like syndrome, episodic ketosis, and metabolic acidosis. The current study presents a comprehensible layout of ACADS network, its functional strategies and candidate disease approach associated with ACADS network. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Psychometric properties of Frustration Discomfort Scale in a Turkish sample.

    Science.gov (United States)

    Ozer, Bilge Uzun; Demir, Ayhan; Harrington, Neil

    2012-08-01

    The present study assessed the psychometric properties of the Frustration Discomfort Scale for Turkish college students. The Frustration Discomfort Scale (FDS), Procrastination Assessment Scale-Student, and Rosenberg Self-Esteem Scale were administered to a sample of 171 (98 women, 73 men) Turkish college students. The results of the confirmatory factor analysis yielded fit index values demonstrating viability of the four-dimensional solution as in the original. Findings also revealed that, as predicted, the Discomfort Intolerance subscale of Turkish FDS was most strongly correlated with procrastination. Overall results provided evidence for the factor validity and reliability of the Turkish version of the scale for use in a Turkish population.

  12. Study of Efficiency Calibrations of HPGe Detectors for Radioactivity Measurements of Environmental Samples

    International Nuclear Information System (INIS)

    Harb, S.; Salahel Din, K.; Abbady, A.

    2009-01-01

    In this paper, we describe a method of calibrating of efficiency of a HPGe gamma-ray spectrometry of bulk environmental samples (Tea, crops, water, and soil) is a significant part of the environmental radioactivity measurements. Here we will discuss the full energy peak efficiency (FEPE) of three HPGe detectors it as a consequence, it is essential that the efficiency is determined for each set-up employed. Besides to take full advantage at gamma-ray spectrometry, a set of efficiency at several energies which covers the wide the range in energy, the large the number of radionuclides whose concentration can be determined to measure the main natural gamma-ray emitters, the efficiency should be known at least from 46.54 keV ( 210 Pb) to 1836 keV ( 88 Y). Radioactive sources were prepared from two different standards, a first mixed standard QC Y 40 containing 210 Pb, 241 Am, 109 Cd, and Co 57 , and the second QC Y 48 containing 241 Am, 109 Cd, 57 Co, 139 Ce, 113 Sn, 85 Sr, 137 Cs, 88 Y, and 60 Co is necessary in order to calculate the activity of the different radionuclides contained in a sample. In this work, we will study the efficiency calibration as a function of different parameters as:- Energy of gamma ray from 46.54 keV ( 210 Pb) to 1836 keV ( 88 Y), three different detectors A, B, and C, geometry of containers (point source, marinelli beaker, and cylindrical bottle 1 L), height of standard soil samples in bottle 250 ml, and density of standard environmental samples. These standard environmental sample must be measured before added standard solution because we will use the same environmental samples in order to consider the self absorption especially and composition in the case of volume samples.

  13. Sophistication of 14C measurement at JAEA-AMS-MUTSU. Attempt on a small quantity of sample

    International Nuclear Information System (INIS)

    Tanaka, Takayuki; Kabuto, Shoji; Kinoshita, Naoki; Yamamoto, Nobuo

    2010-01-01

    In the investigations on substance dynamics using the molecular weight and chemical fractionation, the utilization of 14 C measurement by an accelerator mass spectrometry (AMS) have started. As a result of the fractionation, sample contents required for AMS measurement have been downsized. We expect that this trend toward a small quantity of sample will be steadily accelerated in the future. As 14 C measurement by AMS established at Mutsu office require about 2 mg of sample content at present, our AMS lags behind the others in the trend. We try to downsize the needed sample content for 14 C measurement by our AMS. In this study, we modified the shape of the target-piece in which the sample is packed and which is regularly needed to radiocarbon measurement by our AMS. Moreover, we improved on the apparatus needed to pack the sample. As a result of the improvement, we revealed that it is possible to measure the 14 C using our AMS even by the amount of the sample of about 0.5 mg. (author)

  14. Effects of Coatings on the High-Cycle Fatigue Life of Threaded Steel Samples

    Science.gov (United States)

    Eder, M. A.; Haselbach, P. U.; Mishin, O. V.

    2018-05-01

    In this work, high-cycle fatigue is studied for threaded cylindrical high-strength steel samples coated using three different industrial processes: black oxidation, normal-temperature galvanization and high-temperature galvanization. The fatigue performance in air is compared with that of uncoated samples. Microstructural characterization revealed the abundant presence of small cracks in the zinc coating partially penetrating into the steel. This is consistent with the observation of multiple crack initiation sites along the thread in the galvanized samples, which led to crescent type fracture surfaces governed by circumferential growth. In contrast, the black oxidized and uncoated samples exhibited a semicircular segment type fracture surface governed by single-sided growth with a significantly longer fatigue life. Numerical fatigue life prediction based on an extended Paris-law formulation has been conducted on two different fracture cases: 2D axisymmetric multisided crack growth and 3D single-sided crack growth. The results of this upper-bound and lower-bound approach are in good agreement with experimental data and can potentially be used to predict the lifetime of bolted components.

  15. The study of chemical forms of mercury in human hair and other bio-environmental samples

    International Nuclear Information System (INIS)

    Kratzer, K.; Benes, P.

    1995-01-01

    The results of the continued studies on methods of analysis for forms of mercury in hair, and of the distribution of mercury among inorganic and organic forms in human hair are described. A new method for determining methylmercury has been developed, based on the selective leaching of methylmercury from hair using 2M hydrochioric acid. This method was used, in combination with the determination of mercury by atomic absorption spectrometry, for the analysis of mercury forms in three samples of human hair and two samples of fish homogenate. Good reproducibility of parallel determinations was obtained. The results were compared with literature data for the samples, or with the results of the analysis of the same samples by extraction method described earlier. Good agreement was also found between these methods. Further experiments were concerned with the study of the effect of radiation sterilization on the forms of mercury in hair, of the speciation of 203 Hg formed by irradiation of hair in nuclear reactor and with the labelling of a large batch of human hair with methylmercury. (author)

  16. Experimental Investigation Of Microbially Induced Corrosion Of Test Samples And Effect Of Self-assembled Hydrophobic Monolayers. Exposure Of Test Samples To Continuous Microbial Cultures, Chemical Analysis, And Biochemical Studies

    CERN Document Server

    Laurinavichius, K S

    1998-01-01

    Experimental Investigation Of Microbially Induced Corrosion Of Test Samples And Effect Of Self-assembled Hydrophobic Monolayers. Exposure Of Test Samples To Continuous Microbial Cultures, Chemical Analysis, And Biochemical Studies

  17. Trace metals analysis in molybdenite mineral sample

    International Nuclear Information System (INIS)

    Tamrakar, Praveen Kumar; Pitre, K.S.

    2000-01-01

    DC polarography and other related techniques, viz., DPP and DPASV have been successfully used for the simultaneous determination of trace metals in molybdenite mineral sample. The polarograms and voltammograms of sample solution have been recorded in 0.1 M (NH 4 ) 2 tartrate supporting electrolyte at two different pH values i.e., 2.7±0.1 and 9.0±0.1. The results indicate the presence of Cu 2+ , Mo 6+ , Cd 2+ , Ni 2+ , In 3+ , Fe 3+ and W 6+ metal ions in the sample. For the determination of tungsten(VI), 11 M HCl has been used as supporting electrolyte. Tungsten(VI) produces a well defined wave/peak with E 1/2 /Ep=-0.42V/-0.48V vs SCE in 11 M HCl. The quantitative analysis by the method of standard addition shows the mineral sample to have the following composition, Cu 2+ ( 14.83), Mo 6+ (253.70), Cd 2+ (41.36), Ni 2+ (16.08), In 3+ (3.06), Fe 3+ (83.00)and W 6+ (4.14 )mg/g of the sample. Statistical treatment of the observed voltammetric data reveals high accuracy and good precision of determination. The observed voltammetric results are comparable with those obtained using AAS method. (author)

  18. Likelihood inference of non-constant diversification rates with incomplete taxon sampling.

    Directory of Open Access Journals (Sweden)

    Sebastian Höhna

    Full Text Available Large-scale phylogenies provide a valuable source to study background diversification rates and investigate if the rates have changed over time. Unfortunately most large-scale, dated phylogenies are sparsely sampled (fewer than 5% of the described species and taxon sampling is not uniform. Instead, taxa are frequently sampled to obtain at least one representative per subgroup (e.g. family and thus to maximize diversity (diversified sampling. So far, such complications have been ignored, potentially biasing the conclusions that have been reached. In this study I derive the likelihood of a birth-death process with non-constant (time-dependent diversification rates and diversified taxon sampling. Using simulations I test if the true parameters and the sampling method can be recovered when the trees are small or medium sized (fewer than 200 taxa. The results show that the diversification rates can be inferred and the estimates are unbiased for large trees but are biased for small trees (fewer than 50 taxa. Furthermore, model selection by means of Akaike's Information Criterion favors the true model if the true rates differ sufficiently from alternative models (e.g. the birth-death model is recovered if the extinction rate is large and compared to a pure-birth model. Finally, I applied six different diversification rate models--ranging from a constant-rate pure birth process to a decreasing speciation rate birth-death process but excluding any rate shift models--on three large-scale empirical phylogenies (ants, mammals and snakes with respectively 149, 164 and 41 sampled species. All three phylogenies were constructed by diversified taxon sampling, as stated by the authors. However only the snake phylogeny supported diversified taxon sampling. Moreover, a parametric bootstrap test revealed that none of the tested models provided a good fit to the observed data. The model assumptions, such as homogeneous rates across species or no rate shifts, appear

  19. Applicability of Non-Invasive Sampling in Population Genetic Study of Taiwanese Macaques (Macaca cyclopis

    Directory of Open Access Journals (Sweden)

    Jui-Hua Chu

    2006-12-01

    Full Text Available This paper presents a pilot study conducted to test the applicability of non-invasive sampling approach in population genetic studies of Taiwanese macaques (Macaca cyclopis. Monkey feces were collected in the field and used as non-invasive DNA sources. PCR success rates of both microsatellite and mitochondrial DNA markers were examined. When compared with other studies by non-invasive genetic sampling of different mammal species, success rate of microsatellite PCR amplification is low (42.4%, N = 181 while that of mtDNA PCR amplification is acceptable (66.5%, N = 334. The low PCR success rate and poor PCR repeatability of microsatellite alleles due to allelic dropout and false alleles make it difficult to obtain a reliable microsatellite data set. However, the difficulties may be overcome by new techniques.

  20. Episodic sexual transmission of HIV revealed by molecular phylodynamics.

    Directory of Open Access Journals (Sweden)

    Fraser Lewis

    2008-03-01

    Full Text Available The structure of sexual contact networks plays a key role in the epidemiology of sexually transmitted infections, and their reconstruction from interview data has provided valuable insights into the spread of infection. For HIV, the long period of infectivity has made the interpretation of contact networks more difficult, and major discrepancies have been observed between the contact network and the transmission network revealed by viral phylogenetics. The high rate of HIV evolution in principle allows for detailed reconstruction of links between virus from different individuals, but often sampling has been too sparse to describe the structure of the transmission network. The aim of this study was to analyze a high-density sample of an HIV-infected population using recently developed techniques in phylogenetics to infer the short-term dynamics of the epidemic among men who have sex with men (MSM.Sequences of the protease and reverse transcriptase coding regions from 2,126 patients, predominantly MSM, from London were compared: 402 of these showed a close match to at least one other subtype B sequence. Nine large clusters were identified on the basis of genetic distance; all were confirmed by Bayesian Monte Carlo Markov chain (MCMC phylogenetic analysis. Overall, 25% of individuals with a close match with one sequence are linked to 10 or more others. Dated phylogenies of the clusters using a relaxed clock indicated that 65% of the transmissions within clusters took place between 1995 and 2000, and 25% occurred within 6 mo after infection. The likelihood that not all members of the clusters have been identified renders the latter observation conservative.Reconstruction of the HIV transmission network using a dated phylogeny approach has revealed the HIV epidemic among MSM in London to have been episodic, with evidence of multiple clusters of transmissions dating to the late 1990s, a period when HIV prevalence is known to have doubled in this