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Sample records for assessing meiofaunal variation

  1. Assessing meiofaunal variation among individuals utilising morphological and molecular approaches: an example using the Tardigrada

    Directory of Open Access Journals (Sweden)

    Linse Katrin

    2008-04-01

    Full Text Available Abstract Background Meiofauna – multicellular animals captured between sieve size 45 μm and 1000 μm – are a fundamental component of terrestrial, and marine benthic ecosystems, forming an integral element of food webs, and playing a critical roll in nutrient recycling. Most phyla have meiofaunal representatives and studies of these taxa impact on a wide variety of sub-disciplines as well as having social and economic implications. However, studies of variation in meiofauna are presented with several important challenges. Isolating individuals from a sample substrate is a time consuming process, and identification requires increasingly scarce taxonomic expertise. Finding suitable morphological characters in many of these organisms is often difficult even for experts. Molecular markers are extremely useful for identifying variation in morphologically conserved organisms. However, for many species markers need to be developed de novo, while DNA can often only be extracted from pooled samples in order to obtain sufficient quantity and quality. Importantly, multiple independent markers are required to reconcile gene evolution with species evolution. In this primarily methodological paper we provide a proof of principle of a novel and effective protocol for the isolation of meiofauna from an environmental sample. We also go on to illustrate examples of the implications arising from subsequent screening for genetic variation at the level of the individual using ribosomal, mitochondrial and single copy nuclear markers. Results To isolate individual tardigrades from their habitat substrate we used a non-toxic density gradient media that did not interfere with downstream biochemical processes. Using a simple DNA release technique and nested polymerase chain reaction with universal primers we were able amplify multi-copy and, to some extent, single copy genes from individual tardigrades. Maximum likelihood trees from ribosomal 18S, mitochondrial

  2. Meiofaunal assemblages associated with native and non-indigenous macroalgae

    Science.gov (United States)

    Veiga, Puri; Sousa-Pinto, Isabel; Rubal, Marcos

    2016-07-01

    Meiofauna is a useful tool to detect effects of different disturbances; however, its relevance in the frame of biological invasions has been almost fully neglected. Meiofaunal assemblages associated with the invasive macroalga Sargassum muticum were studied and compared with those associated with two native macroalgae (Bifurcaria bifurcata and Chondrus crispus). We used a linear mixed model to determine the influence of habitat size (i.e. macroalgal biomass) in shaping meiofaunal assemblages. Results showed that habitat size (i.e. macroalgal biomass) shaped meiofaunal assemblages influencing its abundance, richness and structure. However, the identity of macroalga (i.e. species) appears also to play a significant role, particularly the differences of complexity among the studied species may shape their meiofaunal assemblages. Finally, the invasive macroalga appears to influence positively species richness. Our results highlight the need of including different faunal components to achieve a comprehensive knowledge on effects of invasive macroalgae and that meiofaunal assemblages may be a valuable tool to examine them.

  3. Response of meiofaunal and nematode communities to sewage pollution abatement: a field transplantation experiment

    Institute of Scientific and Technical Information of China (English)

    LIU Xiaoshou; CHEUNG Siu Gin; SHIN Paul K.S

    2011-01-01

    To assess the recovery rate of meiofaunal and nematode communities upon abatement of sewage pollution,a field transplantation experiment was conducted in Tai Tam,which is a non-polluted,shallow subtidal habitat on the southern portion of Hong Kong Island.The sediments used were from one site located in Victoria Harbour that was heavily influenced by sewage pollution,and one site in the outside-harbor area,which was relatively clean.In addition,sediments from Tai Tam were used as a control.Fresh sediments with meiofauna were collected from the aforementioned sites,placed in plastic trays and transplanted to Tai Tam.Sediments were retrieved at the beginning of the experiment and at 1-,3-,and 8-weeks after transplantation for analysis of the meiofaunal and nematode communities as well as the sediment characteristics.The results showed that the meiofaunal and nematode communities in the control sediments were consistent at the four sampling periods,while it took three and eight weeks,respectively,for the nematode communities from the outside-harbor and inside-harbor sites to become similar to the control.These findings indicated that the relatively poor habitat quality and the nematode community composition in the sewage polluted inside-harbor sediments required a longer time for recovery than samples from the better habitat quality and the nematode community composition in the outside-harbor sediments.

  4. Comparison of meiofaunal abundance in two mangrove wetlands in Tong'an Bay, Xiamen, China

    Science.gov (United States)

    Zhou, Xiping; Cai, Lizhe; Fu, Sujing

    2015-10-01

    To compare meiofaunal community in the two mangrove wetlands in Tong'an Bay, Xiamen, China, and probe the response of meiofauna to high organic matter, sampling was carried out in Fenglin and Xiang'an mangrove wetlands in the bay. The results showed that the Ne/Co ratio (nematode to benthic copepod) and organic matter in Fenglin mangrove wetland were higher than those in Xiang'an mangrove wetland. The meiofaunal abundance in Fenglin mangrove was all lower than that in Xiang'an mangrove wetland in summer, autumn and spring, while the meiofaunal abundance in Fenglin mangrove was higher than that in Xiang'an mangrove wetland in winter. Two-way ANOVA results showed that the meiofaunal abundance and nematode abundance were significantly different between regions, seasons and region×season. With all the results in the present study, we confirmed that the positive response of meiofaunal and nematode abundance were only detected for medium organic matter contents according to the Xiang'an wetland's level, and that the distribution of meiofaunal abundance would be influenced by sand content. Higher copepod abundance and lower N/C value usually suggest better environmental quality.

  5. A preliminary study of freshwater meiofaunal communities at Greenwich Island, South Shetland Islands, Antarctica

    Institute of Scientific and Technical Information of China (English)

    Soraya J. Silva; Minerva Cordovés; Nory González; Leinny González

    2015-01-01

    Meiofaunal communities of three small, shallow freshwater habitats sampled during the austral summer of 2013 in Greenwich Island, South Shetland Islands, Antarctica, are reported. Communities are dominated by tardigrades (85%), nematodes (11%), and rotifers (3%). Collembola, Oligochaeta, crustacean larvae (nauplii) and unidentified organisms account for 0.3%. Total meiofaunal densities reach 11 770 ind∙cm-2, with mean densities (ind∙cm−2) of 1 365.83 ± 2 716.65 (Zone A), 523.67 ± 1 166.48 (Zone B) and 72.17 ± 110.78 (Zone C). Given the age of freshwater habitats, and the general lack of higher-trophic level predatory taxa, those species we report are likely early stage colonizers, and these communities are at an early stage of ecological succession. Non-parametrical analysis revealed the main variables influencing meiofaunal density and distribution are related to granulometric characteristics of sediments and microphytobenthic biomass. There were close relationships between meiofaunal abundance and microphytobenthic biomass, which indicates that benthic microalgae significantly influence meiofaunal distribution. A strong correlation between nematode abundance and the percentage of silt, clay and carbon in the sediment was also shown by canonical correspondence analysis and Spearman rank correlation.

  6. Deep-sea habitat heterogeneity influence on meiofaunal communities in the Gulf of Guinea

    OpenAIRE

    Van Gaever, S; Galeron, J.; M. Sibuet; Vanreusel, A.

    2009-01-01

    To estimate the degree of spatial heterogeneity of benthic deep-sea communities, we carried out a multiple-scale (from m's to 200 km) investigation in the Congo-Angola margins (Equatorial West African margin, 3150–4800 m) in which we examined the metazoan meiofauna at a variety of habitats along the Congo Channel system and in the associated cold seep. We investigate the structure, density, vertical distribution patterns in the sediment and biomass of meiofaunal communities in the Gulf of Gui...

  7. Cryptic species in tropic sands--interactive 3D anatomy, molecular phylogeny and evolution of meiofaunal Pseudunelidae (Gastropoda, Acochlidia.

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    Timea P Neusser

    Full Text Available BACKGROUND: Towards realistic estimations of the diversity of marine animals, tiny meiofaunal species usually are underrepresented. Since the biological species concept is hardly applicable on exotic and elusive animals, it is even more important to apply a morphospecies concept on the best level of information possible, using accurate and efficient methodology such as 3D modelling from histological sections. Molecular approaches such as sequence analyses may reveal further, cryptic species. This is the first case study on meiofaunal gastropods to test diversity estimations from traditional taxonomy against results from modern microanatomical methodology and molecular systematics. RESULTS: The examined meiofaunal Pseudunela specimens from several Indo-Pacific islands cannot be distinguished by external features. Their 3D microanatomy shows differences in the organ systems and allows for taxonomic separation in some cases. Additional molecular analyses based on partial mitochondrial cytochrome c oxidase subunit I (COI and 16S rRNA markers revealed considerable genetic structure that is largely congruent with anatomical or geographical patterns. Two new species (Pseudunela viatoris and P. marteli spp. nov. are formally described integrating morphological and genetic analyses. Phylogenetic analysis using partial 16S rRNA, COI and the nuclear 18S rRNA markers shows a clade of Pseudunelidae species as the sister group to limnic Acochlidiidae. Within Pseudunela, two subtypes of complex excretory systems occur. A complex kidney already evolved in the ancestor of Hedylopsacea. Several habitat shifts occurred during hedylopsacean evolution. CONCLUSIONS: Cryptic species occur in tropical meiofaunal Pseudunela gastropods, and likely in other meiofaunal groups with poor dispersal abilities, boosting current diversity estimations. Only a combined 3D microanatomical and molecular approach revealed actual species diversity within Pseudunela reliably. Such

  8. Meiofaunal distributions on the Peru margin:. relationship to oxygen and organic matter availability

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    Neira, Carlos; Sellanes, Javier; Levin, Lisa A.; Arntz, Wolf E.

    2001-11-01

    A quantitative study of metazoan meiofauna was carried out on bathyal sediments (305, 562, 830 and 1210 m) along a transect within and beneath the oxygen minimum zone (OMZ) in the southeastern Pacific off Callao, Peru (12°S). Meiobenthos densities ranged from 1517 (upper slope, middle of OMZ) to 440-548 ind. 10 cm -2 (lower slope stations, beneath the OMZ). Nematodes were the numerically dominant meiofaunal taxon at every station, followed by copepods and nauplii. Increasing bottom-water oxygen concentration and decreasing organic matter availability downslope were correlated with observed changes in meiofaunal abundance. The 300-m site, located in the middle of the OMZ, differed significantly in meiofaunal abundance, dominance, and in vertical distribution pattern from the deeper sites. At 305 m, nematodes amounted to over 99% of total meiofauna; about 70% of nematodes were found in the 2-5 cm interval. At the deeper sites, about 50% were restricted to the top 1 cm. The importance of copepods and nauplii increased consistently with depth, reaching ˜12% of the total meiofauna at the deepest site. The observation of high nematode abundances at oxygen concentrations preservation of organic matter leading to high food availability and quality. Food input and quality, represented here by chloroplastic pigment equivalents (CPE) and sedimentary labile organic compounds (protein, carbohydrates and lipids), were strongly, positively correlated with nematode abundance. By way of contrast, oxygen exhibited a strong negative correlation, overriding food availability, with abundance of other meiofauna such as copepods and nauplii. These taxa were absent at the 300-m site. The high correlation of labile organic matter (C-LOM, sum of carbon contents in lipids, proteins and carbohydrates) with CPE (Pearson's r=0.99, p<0.01) suggests that most of the sedimentary organic material sampled was of phytodetrital origin. The fraction of sediment organic carbon potentially available to

  9. Variation in Students' Conceptions of Self-Assessment and Standards

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    Heng Kiat Kelvin Tan

    2011-01-01

    Full Text Available This paper reports the results of a phenomenographic study on the different ways that secondary students understood and utilized student self-assessment and how various ego types could affect the accuracy of self-assessment. The study sought to contribute to the growing literature which recognizes the critical role that students play in assessment processes, and in particular the different roles that they assume in student self-assessment. The results of the study provide insights into how different students experience self-assessment by articulating the variation in the perception and purposes of assessing one's own learning. This variation is depicted as a hierarchy of logically related students' conceptions of self-assessment.

  10. Spatial variation in meiofaunal abundance of some coralline beaches of Mauritius

    Digital Repository Service at National Institute of Oceanography (India)

    Ingole, B.S.; Ansari, Z.A.; Parulekar, A.H.

    the sampling sites and were poorly correlated with sediment granulometry. Contribution of meiofauna to the secondary production was high. Based on the present study Mauritius beaches can be classified as moderate in terms of the benthic biomass (159-1479 mg m...

  11. Cryptic Species in Tropic Sands - Interactive 3D Anatomy, Molecular Phylogeny and Evolution of Meiofaunal Pseudunelidae (Gastropoda, Acochlidia)

    OpenAIRE

    Neusser, Timea P.; Jörger, Katharina M; Schrödl, Michael

    2011-01-01

    Background Towards realistic estimations of the diversity of marine animals, tiny meiofaunal species usually are underrepresented. Since the biological species concept is hardly applicable on exotic and elusive animals, it is even more important to apply a morphospecies concept on the best level of information possible, using accurate and efficient methodology such as 3D modelling from histological sections. Molecular approaches such as sequence analyses may reveal further, cryptic species. T...

  12. Neuromuscular Structure, Evolution and Development in Meiofaunal Annelids with Special Focus on Dinophilus gyrociliatus (Dinophilidae)

    DEFF Research Database (Denmark)

    Kerbl, Alexandra

    BACKGROUND: The majority of annelid neuromorphological studies addresses macroscopic forms such as the well-studied Platynereis dumerilii; microscopic annelids are generally neglected. Several of these animals have remarkably smaller, compact brains composed of significantly fewer cells and having...... less complex sensory structures. Yet, very little is still known on how these small brains are organized to fulfil basic functions. This study addresses the structure, evolution and development of neuromuscular systems within two exclusively meiofaunal lineages Lobatocerebridae and Dinophilidae...

  13. Microbial-meiofaunal interrelationships in coastal sediments of the Red Sea.

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    El-Serehy, Hamed A; Al-Rasheid, Khaled A; Al-Misned, Fahad A; Al-Talasat, Abdul Allah R; Gewik, Mohamed M

    2016-05-01

    Population density and biomass of bacteria and meiofauna were investigated seasonally in the sediments of the north-western bank of Red Sea. Samples of sediments were collected seasonally from three different stations to determine microphytobenthic biomass (chlorophyll a), protein, lipid, carbohydrate, and total organic matter concentrations. These investigations revealed that microbial components tended to increase their dominancy, whereas sensitive meiofauna were extremely reduced during the entire study period. Thus a very low density of the total meiofauna (with an annual average of 109 ± 26 ind./10 cm(2)) was recorded whilst the benthic microbial population densities exhibited higher values (ranging from 0.31 ± 0.02 × 10(8) to 43.67 ± 18.62 × 10(8)/g dry sediment). These changes in the relative importance analysis of benthic microbial components versus meiofaunal ones seem to be based on the impact of organic matter accumulation on the function and structure of these benthic communities. Proteins, lipids and carbohydrates showed very low concentration values, and the organic matter mostly consisted of carbohydrates, reflecting lower nutritional values for benthic fauna in general and meiofauna in particular. The distribution of microbial and meiofaunal communities seems to be dependent on the quality of the organic matter rather than on its quantity. Total organic matter concentrations varied between 5.8 and 7.6 mg/g, with organic carbon accounting for only 32% of the total organic matter. Chlorophyll a attained very low values, fluctuating between 0.11 and 0.56 μg/g, indicating the oligotrophy of the studied area. The very low concentration of chlorophyll a in the Red Sea sediment suggests that the sedimentary organic matter, heterotrophic bacteria and/or protozoa constitute an alternative resource that is consumed by meiofauna when algae are less abundant. Protozoa, therefore, represent the "missing link in bacteria-meiofauna interaction

  14. Deep-sea habitat heterogeneity influence on meiofaunal communities in the Gulf of Guinea

    Science.gov (United States)

    Van Gaever, Saskia; Galéron, Joëlle; Sibuet, Myriam; Vanreusel, Ann

    2009-12-01

    To estimate the degree of spatial heterogeneity of benthic deep-sea communities, we carried out a multiple-scale (from m's to 200 km) investigation in the Congo-Angola margins (Equatorial West African margin, 3150-4800 m) in which we examined the metazoan meiofauna at a variety of habitats along the Congo Channel system and in the associated cold seep. We investigate the structure, density, vertical distribution patterns in the sediment and biomass of meiofaunal communities in the Gulf of Guinea and how they are controlled by hydrologic and biogeochemical processes. The meiofaunal communities in the Gulf of Guinea were shaped by heterogeneous conditions on the margin, and reflect the multiple-scale spatial variability that corresponds with the different identified habitats. The two control sites, located at >100 km away from the canyon, were inhabited by very dense and the most diverse meiobenthic communities. Similar meiobenthic communities inhabited the transition zone between the canyon and the cold seep. Sites located along the Congo Channel were obviously affected by the local high-velocity bottom currents and unstable sedimentary conditions in this active submarine system. Extremely low meiobenthic densities and very low proportions in the most surficial sediment layers provided evidence for recently highly disturbed sediments at these sites. The remote operated vehicle (ROV) Victor 6000 provided images of the cold seep, showing a patchy distribution of several types of patchy distributed megafaunal communities dominated by three key symbiotic taxa (Mytilidae, Vesicomyidae and Siboglinidae). These cold seep sediments were colonised by a unique meiobenthic community, characterised by a high small-scale (m's) patchiness, low species richness and the prominent dominance of two large-sized nematode species: Sabatieria mortenseni, which is a cosmopolitan nematode known from littoral habitats, and an undescribed Desmodora species. The high individual body weight of

  15. Variation between self- and mutual assessment in animal contests.

    Science.gov (United States)

    Mesterton-Gibbons, Mike; Heap, Stephen M

    2014-02-01

    Limited resources lead animals into conflicts of interest, which are resolved when an individual withdraws from a direct contest. Current theory suggests that the decision to withdraw can be based on a threshold derived from an individual's own state (self-assessment) or on a comparison between their own state and their opponent's (mutual assessment). The observed variation between these assessment strategies in nature does not conform to theory. Thus, we require theoretical developments that explain the functional significance of different assessment strategies. We consider a hawk-dove game with two discrete classes that differ in fighting ability, in which the players strategically decide on their investment toward mutual assessment. Analysis of the model indicates that there are simultaneous trade-offs relating to assessment strategies. First, weak individuals in a population must decide on whether to acquire information about their opponents at the cost of providing opponents with information about themselves. Secondly, all individuals must decide between investing in mutual assessment and being persistent in contests. Our analysis suggests that the potential for individuals to make errors during contests and differences in the consequences of sharing information within a population may serve as fundamental concepts for explaining variation in assessment strategy. PMID:24464195

  16. Alcohol content variation in the assessment of alcohol consumption.

    Science.gov (United States)

    Martin, C S; Nirenberg, T D

    1991-01-01

    Most investigators have not adequately accounted for the alcohol content of different beverages when assessing alcohol consumption. Considerable research has assessed consumption in terms of the number of standard drinks. A problem with standard drink measures is that different distilled spirits, wines, and malt beverages vary considerably in alcohol content. State-to-state and brand-to-brand variations in the strength of different malt beverage brands are provided, as malt beverage alcohol contents are not contained on labels due to federal and state regulations. Ignoring alcohol content variation when estimating consumption can produce a large amount of error. Alcohol consumption should be assessed in terms of the number, size, and alcohol content of beverages. PMID:1801580

  17. Mesonerilla neridae, n. sp. (Nerillidae): First meiofaunal annelid from deep-sea hydrothermal vents

    DEFF Research Database (Denmark)

    Worsaae, Katrine; Rouse, Greg W

    2009-01-01

    deep-sea hydrothermal vent associated nerillid, this is the first record of an adult meiofaunal annelid from deep-sea hydrothermal vent areas and the first record of Mesonerilla from the deep sea. Based on the new material we here describe a new species of Mesonerilla, M. neridae sp. nov., with nine......) in 2005, six specimens of a new species of Mesonerilla were collected at depths of 2234-2649 m. Samples were taken via DSV Alvin with a slurp gun collecting fine silt and volcanic glass shards in cracks, fissures, and mussel beds from 5-20 m away from active venting areas. As well as being the first...

  18. An assessment of the impact of copper mine tailings disposal on meiofaunal assemblages using microcosm bioassays

    OpenAIRE

    Lee, Matthew R.; Correa, Juan A.

    2007-01-01

    Departamento de Ecologia, Center for Advanced Studies in Ecology and Biodiversity and Estacion Costera de Investigaciones Marinas Facultad de Ciencias Biologicas, Pontificia Universidad Catolica de Chile - Alameda 340--> , Santiago--> - CHILE (Lee, Matthew R.)

  19. Benthic communities in the deep Mediterranean Sea: exploring microbial and meiofaunal patterns in slope and basin ecosystems

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    K. Sevastou

    2012-12-01

    Full Text Available The long held perception of the deep sea consisting of monotonous slopes and uniform oceanic basins has over the decades given way to the idea of a complex system with wide habitat heterogeneity. Under the prism of a highly diverse environment, a large dataset was used to describe and compare spatial patterns of the dominant small-size components of deep-sea benthos, metazoan meiofauna and bacteria, from Mediterranean basins and slopes. A grid of 73 stations sampled at five geographical areas along the central-eastern Mediterranean basin (central Mediterranean, northern Aegean Sea, Cretan Sea, Libyan Sea, eastern Levantine spanning over 4 km in depth revealed a high diversity in terms of both metazoan meiofauna and microbial communities. The higher meiofaunal abundance and richness observed in the northern Aegean Sea highlights the effect of productivity on benthic patterns. Non parametric analyses detected no differences for meiobenthic standing stocks and major taxa diversity (α, β, γ and δ components between the two habitats (basin vs. slope for the whole investigated area and within each region, but revealed significant bathymetric trends: abundance and richness follow the well-known gradient of decreasing values with increasing depth, whereas differentiation diversity (β- and δ-diversity increases with depth. In spite of a similar bathymetric trend observed for nematode genera richness, no clear pattern was detected with regard to habitat type; the observed number of nematode genera suggests higher diversity in slopes, whereas richness estimator Jack1 found no differences between habitats. On the other hand, δ-diversity was higher at the basin habitat, but no differences were found among depth ranges, though turnover values were high in all pairwise comparisons of the different depth categories. Results of multivariate analysis are in line with the above findings, indicating high

  20. Human Variome Project Quality Assessment Criteria for Variation Databases.

    Science.gov (United States)

    Vihinen, Mauno; Hancock, John M; Maglott, Donna R; Landrum, Melissa J; Schaafsma, Gerard C P; Taschner, Peter

    2016-06-01

    Numerous databases containing information about DNA, RNA, and protein variations are available. Gene-specific variant databases (locus-specific variation databases, LSDBs) are typically curated and maintained for single genes or groups of genes for a certain disease(s). These databases are widely considered as the most reliable information source for a particular gene/protein/disease, but it should also be made clear they may have widely varying contents, infrastructure, and quality. Quality is very important to evaluate because these databases may affect health decision-making, research, and clinical practice. The Human Variome Project (HVP) established a Working Group for Variant Database Quality Assessment. The basic principle was to develop a simple system that nevertheless provides a good overview of the quality of a database. The HVP quality evaluation criteria that resulted are divided into four main components: data quality, technical quality, accessibility, and timeliness. This report elaborates on the developed quality criteria and how implementation of the quality scheme can be achieved. Examples are provided for the current status of the quality items in two different databases, BTKbase, an LSDB, and ClinVar, a central archive of submissions about variants and their clinical significance. PMID:26919176

  1. Assessing temporal variations in connectivity through suspended sediment hysteresis analysis

    Science.gov (United States)

    Sherriff, Sophie; Rowan, John; Fenton, Owen; Jordan, Phil; Melland, Alice; Mellander, Per-Erik; hUallacháin, Daire Ó.

    2016-04-01

    Connectivity provides a valuable concept for understanding catchment-scale sediment dynamics. In intensive agricultural catchments, land management through tillage, high livestock densities and extensive land drainage practices significantly change hydromorphological behaviour and alter sediment supply and downstream delivery. Analysis of suspended sediment-discharge hysteresis has offered insights into sediment dynamics but typically on a limited selection of events. Greater availability of continuous high-resolution discharge and turbidity data and qualitative hysteresis metrics enables assessment of sediment dynamics during more events and over time. This paper assesses the utility of this approach to explore seasonal variations in connectivity. Data were collected from three small (c. 10 km2) intensive agricultural catchments in Ireland with contrasting morphologies, soil types, land use patterns and management practices, and are broadly defined as low-permeability supporting grassland, moderate-permeability supporting arable and high-permeability supporting arable. Suspended sediment concentration (using calibrated turbidity measurements) and discharge data were collected at 10-min resolution from each catchment outlet and precipitation data were collected from a weather station within each catchment. Event databases (67-90 events per catchment) collated information on sediment export metrics, hysteresis category (e.g., clockwise, anti-clockwise, no hysteresis), numeric hysteresis index, and potential hydro-meteorological controls on sediment transport including precipitation amount, duration, intensity, stream flow and antecedent soil moisture and rainfall. Statistical analysis of potential controls on sediment export was undertaken using Pearson's correlation coefficient on separate hysteresis categories in each catchment. Sediment hysteresis fluctuations through time were subsequently assessed using the hysteresis index. Results showed the numeric

  2. Data collection variation in preoperative assessment: a literature review

    NARCIS (Netherlands)

    L. Ahmadian; R. Cornet; W.A. van Klei; N.F. de Keizer

    2011-01-01

    This study is a systematic literature review to identify data collected in the preoperative assessment. The PubMed and CINAHL databases were searched for articles published from 1997 to 2007. From the included articles, data items that were described as part of the preoperative assessment were extra

  3. Assessment of Radiation Background Variation for Moving Detection Systems

    Energy Technology Data Exchange (ETDEWEB)

    Miller, James Christopher [Los Alamos National Laboratory; Rennie, John Alan [Los Alamos National Laboratory; Toevs, James Waldo [Los Alamos National Laboratory; Wallace, Darrin J. [Los Alamos National Laboratory; Abhold, Mark Edward [Los Alamos National Laboratory

    2015-07-13

    The introduction points out that radiation backgrounds fluctuate across very short distances: factors include geology, soil composition, altitude, building structures, topography, and other manmade structures; and asphalt and concrete can vary significantly over short distances. Brief descriptions are given of the detection system, experimental setup, and background variation measurements. It is concluded that positive and negative gradients can greatly reduce the detection sensitivity of an MDS: negative gradients create opportunities for false negatives (nondetection), and positive gradients create a potentially unacceptable FAR (above 1%); the location of use for mobile detection is important to understand; spectroscopic systems provide more information for screening out false alarms and may be preferred for mobile use; and mobile monitor testing at LANL accounts for expected variations in the background.

  4. Relevance of phenotypic variation in risk assessment: The scientific viewpoint

    International Nuclear Information System (INIS)

    A number of examples are presented indicating the types of variation that may be expected in the responses of the human population to deleterious agents of an endogeneous or exogenous nature. If one assumes that the variations in repair in the normal population are reflected in large variations in carcinogenic risk per unit of exposure, then the dose-response curves at low doses cannot be extrapolated from high doeses without knowing the distribution of sensitivities among humans. The probability of determining this range by ecpidemiological studies on a random population by small. On the other hand, the probability of determining the range by careful genetic and molecular studies appears high enough so that such experiments now are being carried out. They cannot be carried out on real populations, using chronic exposures. Hence, the ability to estimate dose-response relations in the low dose region on human populations can only be by making theoretical constructs that, in turn, are dependent on fundamental research. 12 refs., 2 tabs

  5. Assessment and seasonal variations of communicable diseases: 3 year study

    Directory of Open Access Journals (Sweden)

    D. Kalyani

    2016-04-01

    Results: Results showed that a total of 34,981 had been treated at the inpatient departments from the year 2011 to 2013. It was observed that communicable diseases constituted about 85% (30,082 of the total disease burden with viral infections being the commonest. Most of the diseases were observed to have a seasonal variation. The most common disease identified was viral fever 8713 (28.96%, secondly acute diarrheal diseases 7965(26.52% followed by enteric fever 2958 (9.83% and malaria 2443(8.12%. The least common were Rabies 80 (0.26 % and pertussis 37 (0.12%. Outbreaks of Measles and Diphtheria were also noted in this study. Conclusions: Many diseases have a seasonal variation and the burden of these diseases could be reduced if we device measures to detect the changes in their trend through the implementation of surveillance programs. The knowledge of the burden of these would also assist the health administrators in allocation of the resources. [Int J Res Med Sci 2016; 4(4.000: 1186-1192

  6. Technical note on probabilistic assessment of one-step-ahead rainfall variation by Split Markov Process

    OpenAIRE

    R. Maity; Prasad, D.

    2011-01-01

    In this paper, Split Markov Process (SMP) is developed to assess one-step-ahead variation of daily rainfall at a rain gauge station. SMP is an advancement of general Markov Process (MP) and specially developed for probabilistic assessment of change in daily rainfall magnitude. The approach is based on a first-order Markov chain to simulate daily rainfall variation at a point through state/sub-state Transitional Probability Matrix (TPM). Th...

  7. Assessment of Variation in Water Quality Index (WQI) of Groundwater in North Goa, India

    OpenAIRE

    Gopal Krishan; C.P. Kumar; Purandara, B. K.; Surjeet Singh; N.C. Ghosh; Suman Gurjar; A. G. Chachadi

    2016-01-01

    A water quality index (WQI) is a tool which numerically summarizes the information from multiple water quality parameters into a single value and this information can be used to assess spatial and temporal variations in overall water quality. However, these indices are time and region specific and may be influenced by local factors. In the present study, water quality index has been worked out to assess the spatial and temporal variation of groundwater quality status for future planning and m...

  8. On the Assessment of Global Terrestrial Reference Frame Temporal Variations

    Science.gov (United States)

    Ampatzidis, Dimitrios; Koenig, Rolf; Zhu, Shengyuan

    2015-04-01

    Global Terrestrial Reference Frames (GTRFs) as the International Terrestrial Reference Frame (ITRF) provide reliable 4-D position information (3-D coordinates and their evolution through time). The given 3-D velocities play a significant role in precise position acquisition and are estimated from long term coordinate time series from the space-geodetic techniques DORIS, GNSS, SLR, and VLBI. GTRFs temporal evolution is directly connected with their internal stability: The more intense and inhomogeneous velocity field, the less stable TRF is derived. The assessment of the quality of the GTRF is mainly realized by comparing it to each individual technique's reference frame. E.g the comparison of GTRFs to SLR-only based TRF gives the sense of the ITRF stability with respect to the Geocenter and scale and their associated rates respectively. In addition, the comparison of ITRF to the VLBI-only based TRF can be used for the scale validation. However, till now there is not any specified methodology for the total assessment (in terms of origin, orientation and scale respectively) of the temporal evolution and GTRFs associated accuracy. We present a new alternative diagnostic tool for the assessment of GTRFs temporal evolution based on the well-known time-dependent Helmert type transformation formula (three shifts, three rotations and scale rates respectively). The advantage of the new methodology relies on the fact that it uses the full velocity field of the TRF and therefore all points not just the ones common to different techniques. It also examines simultaneously rates of origin, orientation and scale. The methodology is presented and implemented to the two existing GTRFs on the market (ITRF and DTRF which is computed from DGFI) , the results are discussed. The results also allow to compare directly each GTRF dynamic behavior. Furthermore, the correlations of the estimated parameters can also provide useful information to the proposed GTRFs assessment scheme.

  9. Variation of a Lightning NOx Indicator for National Climate Assessment

    Science.gov (United States)

    Koshak, William; Vant-Hull, B.; McCaul, E. W.; Peterson, H. S.

    2014-01-01

    Lightning nitrogen oxides (LNOx) indirectly influences our climate since these molecules are important in controlling the concentration of ozone (O3) and hydroxyl radicals (OH) in the atmosphere [Huntrieser et al., 1998]. In support of the National Climate Assessment (NCA) program, satellite Lightning Imaging Sensor (LIS; Christian et al. [1999]; Cecil et al. [2014]) data is used to estimate LNOx production over the southern portion of the conterminous US for the 16 year period 1998-2013.

  10. Variation of a Lightning NOx Indicator for National Climate Assessment

    Science.gov (United States)

    Koshak, William J.; McCaul, Eugene W., Jr.; Peterson, Harold S.; Vant-Hull, Brian

    2014-01-01

    During the past couple of years, an analysis tool was developed by the NASA Marshall Space Flight Center (MSFC) for the National Climate Assessment (NCA) program. The tool monitors and examines changes in lightning characteristics over the conterminous US (CONUS) on a continual basis. In this study, we have expanded the capability of the tool so that it can compute a new climate assessment variable that is called the Lightning NOx Indicator (LNI). Nitrogen oxides (NOx = NO + NO2) are known to indirectly influence our climate, and lightning NOx is the most important source of NOx in the upper troposphere (particularly in the tropics). The LNI is derived using Lightning Imaging Sensor (LIS) data and is computed by summing up the product of flash area x flash brightness over all flashes that occur in a particular region and period. Therefore, it is suggested that the LNI is a proxy to lightning NOx production. Specifically, larger flash areas are consistent with longer channel length and/or more energetic channels, and hence more NOx production. Brighter flashes are consistent with more energetic channels, and hence more NOx production. The location of the flash within the thundercloud and the optical scattering characteristics of the thundercloud are of course complicating factors. We analyze LIS data for the years 2003-2013 and provide geographical plots of the time-evolution of the LNI in order to determine if there are any significant changes or trends between like seasons, or from year to year.

  11. Tnterobserver variation in histopathological assessment of Helicobacter pylori gastritis

    Institute of Scientific and Technical Information of China (English)

    Ozlem Aydin; Reyhan Egilmez; Tuba Karabacak; Arzu Kanik

    2003-01-01

    Because the presence or absence of H pylori infection has important implications for therapeutic decisions based on histological assessment, the reproducibility of Sydney system is important. The study was designed to test the reproducibility of features of Helicobacter pylori gastritis,using the updated Sydney classification.METHODS: Gastric biopsies of 40 randomly selected cases of Hpylori gastritis were scored semiquantitatively by three pathologists. Variables analysed included chronic inflammation,inflammatory activity, atrophy, intestinal metaplasia, H pylori,surface epithelial damage. Κ values below 0.5 represented poor, those between 0.5 and 0.75 good and values over 0.75excellent interobserver agreement.RESULTS: The best interobserver agreement (κ=0.62) was present for intestinal metaplasia. The agreement was the poorest for evaluating atrophy (κ=0.31).CONCLUSION: Although the results of this study were in accordance with some previous studies, an excellent agreement could not be reached for any features of H pylori gastritis. This low degree of concordance is assumed to be due to the personal evaluation differences in grading the features, the lack of standardized diagnostic criteria, and the ignorance to reach a consensus about the methods to be used in grading the features of H pylori gastritis before initiating the study.

  12. The dark side of springs: what drives small-scale spatial patterns of subsurface meiofaunal assemblages?

    Directory of Open Access Journals (Sweden)

    Barbara Fiasca

    2014-02-01

    Full Text Available Springs are amongst the most relevant Groundwater Dependent Ecosystems (GDEs and are key research environments in freshwater ecology and biology. The strict dependency on ground water of surface spring biodiversity is well known, whereas the biodiversity occurring below the spring is very poorly known. This study analyzes copepod assemblages in the subsurface habitat of a karstic rheo-limnocrenic spring in relation to seventeen environmental parameters. Subsurface copepod assemblages were sensitive to microspatial variation in habitat structure, and species distributions were mostly driven by groundwater flowpath and substratum type, resulting in biologically distinct limnocrenic and rheocrenic sectors at the spring system scale. Habitat patchiness was reflected in differences in the microdistribution of subsurface copepods, stygobiotic assemblages being more sensitive to the measured environmental gradients than non-stygobiotic ones. In spite of the apparent stability of spring environments, copepods, as a target group, performed well as descriptors of sediment texture and hydrodynamics, and may offer relevant information for a better understanding of the potential changes generated by anthropogenic disturbance on these ecosystems..

  13. Assessing genetic variation in natural populations of the New World screwworm fly, Cochliomyia hominivorax

    International Nuclear Information System (INIS)

    Full text: Through participation in the FAO/IAEA coordinated research project 'Enabling Technologies for the Expansion of SIT for Old and New World Screwworm Fly', we have been able to analyse samples of New World screwworm fly from across the range of this insect pest. This presentation will bring together data from a range of genetic markers that have been used to assess levels of genetic variation within populations of the New World screwworm fly, Cochliomyia hominivorax. The markers used include: rRNA gene sequences, together with sequence information from protein coding genes, and microsatellites, allowing variation to be assessed at a range of levels from species to population. (author)

  14. Parametric Assessment of Water Use Vulnerability Variations Using SWAT and Fuzzy TOPSIS Coupled with Entropy

    OpenAIRE

    Kwangjai Won; Eun-Sung Chung; Sung-Uk Choi

    2015-01-01

    This study assessed the water use vulnerability to include the uncertainty of the weighting values of evaluation criteria and the annual variations of performance values using fuzzy TOPSIS coupled with the Shannon entropy method. This procedure was applied to 12 major basins covering about 88% territory of South Korea. Hydrological components were simulated using Soil and Water Assessment Tool (SWAT) of which parameters were optimally calibrated using SWAT-CUP model. The 15 indicators includ...

  15. The Influence of deep-sea bed CO2 sequestration on small metazoan (meiofaunal) community structure and function

    Energy Technology Data Exchange (ETDEWEB)

    Carman, Kevin R; Fleeger, John W; Thistle, David

    2013-02-17

    We conducted a series of experiments in Monterey Submarine Canyon to examine potential ecological impacts of deep-ocean CO2 sequestration. Our focus was on responses of meiofaunal invertebrates (< 1 mm body length) living within the sediment at depths ranging between 3000-3600 m. Our particular emphasis was on harpacticoid copepods and nematodes. In the first phase of our DOE funding, we reported findings that suggest substantial (~80%) mortality to harpacticoid copepods. In the second phase of our funding we published additional findings from phase one and conducted follow-up experiments in the Monterey Canyon and in the laboratory. In one experiment we looked for evidence that meiofauna seek to escape areas where CO2 concentrations are elevated. “Emergence traps” near the source of the CO2-rich seawater caught significantly more harpacticoids than those far from it. The harpacticoids apparently attempted to escape from the advancing front of carbon dioxide-rich seawater and therefore presumably found exposure to it to be stressful. Although most were adversely affected, species differed significantly in the degree of their susceptibility. Unexpectedly, six species showed no effect and may be resistant. The hypothesis that harpacticoids could escape the effects of carbon dioxide-rich seawater by moving deeper into the seabed was not supported. Exposure to carbon dioxide-rich seawater created partially defaunated areas, but we found no evidence that disturbance-exploiting harpacticoid species invaded during the recovery of the affected area. Based on a detailed analysis of nematode biovolumes, we postulated that the nematode community in Monterey Canyon throughout the upper 3 cm suffered a high rate of mortality after exposure to CO2, and that nematodes were larger because postmortem expansions in body length and width occurred. Decomposition rates were probably low and corpses did not disintegrate in 30 days. The observable effects of a

  16. Global assessment of genomic variation in cattle by genome resequencing and high-throughput genotyping

    DEFF Research Database (Denmark)

    Zhan, Bujie; Fadista, João; Thomsen, Bo;

    2011-01-01

    sequence of a single Holstein Friesian bull with data from single nucleotide polymorphism (SNP) and comparative genomic hybridization (CGH) array technologies to determine a comprehensive spectrum of genomic variation. The performance of resequencing SNP detection was assessed by combining SNPs that were...... of split-read and read-pair approaches proved to be complementary in finding different signatures. CNVs were identified on the basis of the depth of sequenced reads, and by using SNP and CGH arrays. Conclusions Our results provide high resolution mapping of diverse classes of genomic variation in an...

  17. Inter-doctor variations in the assessment of functional incapacities by insurance physicians

    Directory of Open Access Journals (Sweden)

    Schellart Antonius JM

    2011-11-01

    Full Text Available Abstract Background The aim of this study was to determine the - largely unexplored - extent of systematic variation in the work disability assessment by Dutch insurance physicians (IPs of employees on long-term sick leave, and to ascertain whether this variation was associated with the individual characteristics and opinions of IPs. Methods In March 2008 we conducted a survey among IPs on the basis of the 'Attitude - Social norm - self-Efficacy' (ASE model. We used the ensuing data to form latent variables for the ASE constructs. We then linked the background variables and the measured constructs for IPs (n = 199 working at regional offices (n = 27 to the work disability assessments of clients (n = 83,755 and their characteristics. These assessments were carried out between July 2003 and April 2008. We performed multilevel regression analysis on three important assessment outcomes: No Sustainable Capacity or Restrictions for Working Hours (binominal, Functional Incapacity Score (scale 0-6 and Maximum Work Disability Class (binominal. We calculated Intra Class Correlations (ICCs at IP level and office level and explained variances (R2 for the three outcomes. A higher ICC reflects stronger systematic variation. Results The ICCs at IP level were approximately 6% for No Sustainable Capacity or Restrictions for Working Hours and Maximum Work Disability Class and 12% for Functional Incapacity Score. Background IP variables and the measured ASE constructs for physicians contributed very little to the variation - at most 1%. The ICCs at office level ranged from 0% to around 1%. The R2 was 11% for No Sustainable Capacity or Restrictions for Working Hours, 19% for Functional Incapacity Score and 37% for Maximum Work Disability Class. Conclusion Our study uncovered small to moderate systematic variations in the outcome of disability assessments in the Netherlands. However, the individual characteristics and opinions of insurance physicians have very

  18. Assessment of Variation in Water Quality Index (WQI of Groundwater in North Goa, India

    Directory of Open Access Journals (Sweden)

    Gopal Krishan

    2016-04-01

    Full Text Available A water quality index (WQI is a tool which numerically summarizes the information from multiple water quality parameters into a single value and this information can be used to assess spatial and temporal variations in overall water quality. However, these indices are time and region specific and may be influenced by local factors. In the present study, water quality index has been worked out to assess the spatial and temporal variation of groundwater quality status for future planning and management of North Goa. Data of 19 groundwater samples were collected in the year 2005 during January, March and April, are used for the analysis. The Water Quality Index has been computed using four parameters viz. pH, Total Dissolved Solids, Total Hardness and Chloride. The WQI results show that the overall water quality class is ‘good’ and water is acceptable for domestic use.

  19. Assessment of high to low frequency variations of isoprene emission rates using a neural network approach

    OpenAIRE

    Boissard, C.; Chervier, F.; Dutot, A. L.

    2007-01-01

    International audience Using a statistical approach based on artificial neural networks, an emission algorithm (ISO_LF) accounting for high (instantaneous) to low (seasonal) frequency variations was developed for isoprene. ISO_LF was optimised using an isoprene emission data base (ISO-DB) specifically designed for this work. ISO-DB consists of 1321 emission rates collected in the literature, together with 34 environmental variables, measured or assessed using NCDC (National Climatic Data C...

  20. Assessing the impact of climate variability and human activities on streamflow variation

    OpenAIRE

    Chang, J.; Zhang, H.; Wang, Y.; Zhu, Y

    2015-01-01

    Water resources in river systems have been changing under the impact of both climate variability and human activities. Assessing the respective impact on decadal streamflow variation is important for water resource management. By using an elasticity-based method and calibrated TOPMODEL and VIC hydrological models, we quantitatively isolated the relative contributions that human activities and climate variability made to decadal streamflow changes in Jinghe basin, located in ...

  1. Assessing the impact of climate variability and human activity to streamflow variation

    OpenAIRE

    Chang, J.; Zhang, H.; Wang, Y.; Zhu, Y

    2015-01-01

    Water resources in river systems have been changing under the impacts of both climate variability and human activities. Assessing the respective impacts on decadal streamflow variation is important for water resources management. By using an elasticity-based method, calibrated TOPMODEL and VIC hydrologic models, we have quantitatively isolated the relative contributions that human activity and climate variability made to decadal streamflow changes in Jinhe b...

  2. Assessing the impact of climate variability and human activities on streamflow variation

    OpenAIRE

    Chang, Jianxia; Zhang, Hongxue; Wang, Yimin; Zhu, Yuelu

    2016-01-01

    Water resources in river systems have been changing under the impact of both climate variability and human activities. Assessing the respective impact on decadal streamflow variation is important for water resource management. By using an elasticity-based method and calibrated TOPMODEL and VIC hydrological models, we quantitatively isolated the relative contributions that human activities and climate variability made to decadal streamflow changes in the Jinghe basin, located...

  3. Assessment of genetic variation in Bulgarian tomato (Solanum lycopersicum L.) genotypes, using fluorescent SSR genotyping platform

    OpenAIRE

    TODOROVSKA, Elena; IVANOVA, Albena; Daniela GANEVA; Galina PEVICHAROVA; Molle, Emil; Bojinov, Bojin; Radkova, Mariana; Danailov, Zhivko

    2014-01-01

    Genetic variability in modern crops is limited due to domestication and selection processes. Genetic variation in eight Bulgarian tomato varieties and breeding lines (variety Plovdivska karotina, variety IZK Alya, L21β, L53β, L1140, L1116, L975, L984) differing in their morphological and biochemical composition was assessed using a highly efficient and low-cost fluorescent simple sequence repeat (SSR) genotyping platform. Genotyping was conducted with 165 publicly available microsatellite mar...

  4. MCNP Code in Assessment of Variations of Effective Dose with Torso Adipose Tissue Thickness

    International Nuclear Information System (INIS)

    The effective dose is the unite used in the field of radiation protection. It is a well defined doubly weighted uantity involving both physical and biological variables. Several factors may induce variation in the effective dose in different individuals of similar exposure data. One of these factors is the variation of adipose tissue thickness in different exposed individuals. This study essentially concenrs the assessment of the possible variation in the effective dose due to variation in the thickness of adipose tissue. The study was done using MCNP4b code to perform mathematical model of the human body depending on that given to the reference man developed by International Commission of Radiological Protection (ICRP), and calculate the effective dose with different thicknessess of adipose tissues. The study includes a comprehensive appraisal of the Monte Cario simulation, the Medical Internal Radiation Dose (MIRD) model for the human body, and the various mathematical considerations involved in the radiation dose calculations for the various pertinent parts of the human body. The radiation energies considered were 80 KeV, 300 KeV and I MeV, applying two exposure positions; anteroposterior (AP), postero-anterior (PA) with different adipose tissue thickness. This study is a theoretical approach based on detailed mathematical calculations of great precision that deals with all considerations involved in the mechanisms of radiation energy absorption in biological system depending on the variation in the densities of the particular in biological system depending on the variation in the densities of the particular tissues. The results obtained indicate that maximum decrease in effective dose occures with the lowest energy at 5cm adipose tissues thickeness for both AP and PA exposure positions. The results obtained were compared to similar work previsouly done using MCNP4 b showing very good agreement

  5. Assessment of high to low frequency variations of isoprene emission rates using a neural network approach

    Directory of Open Access Journals (Sweden)

    C. Boissard

    2007-08-01

    Full Text Available Using a statistical approach based on artificial neural networks, an emission algorithm (ISO_LF accounting for high (instantaneous to low (seasonal frequency variations was developed for isoprene. ISO_LF was optimised using an isoprene emission data base (ISO-DB specifically designed for this work. ISO-DB consists of 1321 emission rates collected in the literature, together with 34 environmental variables, measured or assessed using NCDC (National Climatic Data Center or NCEP (National Centers for Environmental Predictions meteorological databases. ISO-DB covers a large variety of emitters (25 species and environmental conditions (10° S to 60° N. When only instantaneous environmental regressors (air temperature and photosynthetic active radiation, PAR were used, a maximum of 60% of the overall isoprene variability was assessed and the highest emissions were underestimated. Considering a total of 9 high (instantaneous to low (up to 3 weeks frequency regressors, ISO_LF accounts for up to 91% of the isoprene emission variability, whatever the emission range, species or climate. Diurnal and seasonal variations are correctly reproduced for extit{Ulex europaeus} with a maximum factor of discrepancy of 4. ISO-LF was found to be mainly sensitive to air temperature cumulated over 3 weeks T21 and to instantaneous light L0 and air temperature T0 variations. T21, T0 and L0 only accounts for 76% of the overall variability. The use of ISO-LF for non stored monoterpene emissions was shown to give poor results.

  6. Quantitative Assessment of Cost and Time Implication of Susceptibility of Building Elements to Variation in Nigeria

    Directory of Open Access Journals (Sweden)

    Solomon Olusola Babatunde

    2013-11-01

    Full Text Available A number of research studies have been carried out on the causes and effects of variation on construction project delivery, thereby taking for granted the susceptibility of building elements to variations. This formed the basis of this paper with a view to assessing the cost and time implications of the susceptibility of each building element to variation during construction process in Nigeria. Archival record comprises contract drawings, original bill of quantities, addendum and reduction bill of quantities, and minutes of site meetings among others were used to extract data relating to initial cost, final construction cost, estimated period, final completion period of each building element attributed to variations. The data obtained were analyzed using statistical methods of average, percentage, regression analysis, and analysis of variance (ANOVA. The study identified the building elements having greater than 20% of cost overrun due to variation as earthwork and fillings, frame, windows and external doors, fittings and furnishings, water installation, and external services. The study further identified the building elements having greater than 25% time overrun due to variation as earthwork and fillings, block work (at substructure, upper floors, external walls, wall finishing among others. The results of ANOVA and regression analysis on the building elements cost and time were used to establish models. Thus, the established models are: AFC= 981690 + 1.033AIC; and AFCO= 608390.865 +1.310AIC to predict the average final cost of each building element, and the average final cost overrun of each building element due to variation respectively, where AFC= Average Final Cost, AIC= Average Initial Cost, and AFCO= Average Final Cost Overrun. Also, the study established the model: Y = 1.379(X – 0.251 for predicting the average actual completion period of each building element, where Y= Average Actual Completion Period, and X= Average Estimated Period

  7. Doppler ultrasound for assessment of pulsatility index variation of middle cerebral artery in intrauterine growth retardation

    International Nuclear Information System (INIS)

    To assess variation of pulsatility index of middle cerebral artery (MCA-PI) in intrauterine growth retardation (IUGR). Study Design: Descriptive study. Place and Duration of Study: The study was conducted in department of Radiology, Combined Military Hospital Lahore, from March 2006 to September 2006. Patients and Method: A total 100 patients with IUGR in third trimester were selected. Ultrasound estimation of fetal weight (using fetal biometry) below 10th percentile for that gestational age was labeled as IUGR. MCA-PI value of less than 0.751 was labeled as abnormal. Result: Abnormal values of PI-MCA were found in 79% of IUGR cases while 21% had normal values. Conclusion: PI-MCA is a sensitive modality of assessing IUGR. (author)

  8. Parametric Assessment of Water Use Vulnerability Variations Using SWAT and Fuzzy TOPSIS Coupled with Entropy

    Directory of Open Access Journals (Sweden)

    Kwangjai Won

    2015-08-01

    Full Text Available This study assessed the water use vulnerability to include the uncertainty of the weighting values of evaluation criteria and the annual variations of performance values using fuzzy TOPSIS coupled with the Shannon entropy method. This procedure was applied to 12 major basins covering about 88% territory of South Korea. Hydrological components were simulated using Soil and Water Assessment Tool (SWAT of which parameters were optimally calibrated using SWAT-CUP model. The 15 indicators including hydrological and anthropogenic factors were selected, based on three aspects of climate exposure, sensitivity and adaptive capacity. Their weighting values were objectively quantified using the Entropy method. All performance values of 12 basins obtained from statistic Korea and SWAT simulation were normalized with the consideration of the annual variations from 1991 to 2014 using triangular fuzzy numbers (TFNs. Then, Fuzzy Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS technique was used to quantify the water use vulnerability and rank 12 basins as follows: A12 (Hyeongsan River > A6 (Seomjin River > A5 (Youngsan River > A8 (Mangyung River > A2 (Ansung River > A9 (Dongjin River > A10 (Nakdong River > A3 (Geum River > A4 (Sapgyo River > A11 (Taehwa River > A7 (Tamjin River > A1 (Han River. This framework can be used to determine the spatial priority for sustainable water resources plan and applied to derive the climate change vulnerability on sustainable water resources.

  9. Variation in the Profile of Anxiety Disorders in Boys with an ASD According to Method and Source of Assessment

    Science.gov (United States)

    Bitsika, Vicki; Sharpley, Christopher F.

    2015-01-01

    To determine any variation that might occur due to the type of assessment and source used to assess them, the prevalence of 7 anxiety disorders were investigated in a sample of 140 boys with an Autism spectrum disorder (ASD) and 50 non-ASD (NASD) boys via the Child and Adolescent Symptom Inventory and the KIDSCID Clinical Interview. Boys with an…

  10. Dynamic contrast-enhanced MR imaging to assess physiologic variations of myometrial perfusion

    International Nuclear Information System (INIS)

    To prospectively evaluate the ability of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) to assess physiological microvascular states in normal myometrium. Eighty-five women (62 women of reproductive age, 23 postmenopausal) undergoing DCE-MRI of the pelvis were included. Microvascular parameters for the inner and outer myometrium were analysed using a pharmacokinetic model. These parameters were tissue blood flow (F), blood volume fraction (Vb), permeability-surface area product (PS), interstitial volume fraction (Ve) and lag time (Dt). In the women of reproductive age, the inner myometrium displayed higher F and PS, lower Vb and Ve, and longer Dt than the outer myometrium (p = 0.02, p = 0.01, p = 0.005, p = 0.03 and p = 0.01, respectively). The inner myometrium presented microvascular variations during the menstrual cycle with a pre-ovulatory peak followed by a fall reaching a nadir of F and Vb about 4 days after ovulation. Compared with women of reproductive age, in the postmenopausal state, F and Vb decreased in the outer myometrium, while PS, Ve and Dt increased (p < 0.0001, p = 0.001, p = 0.001, p = 0.03 and p = 0.0004, respectively). DCE-MRI is a non-invasive technique that can measure variations of myometrial microcirculation, and thereby be potentially useful to help characterize the role and states of the myometrium in assisted reproductive therapy. (orig.)

  11. Entropy and coefficient of variation (CV as tools for assessing power quality

    Directory of Open Access Journals (Sweden)

    J. H. Estrada

    2011-10-01

    Full Text Available This paper presents several concepts and techniques for quantifying electric signal entropy and variability for assessing power quality, showing their irregularities, such as the electrical sine wave which delivers power to industry and homes. The paper will review these concepts and show some magnetic radiated waves measurements taken below 115 KV electricity line circuits in the city of Manizales (Colombia through non-invasive and indirect measurement of the complexity of the current transported by the supply. Entropy, as an accepted indicator of physical complexity, is proportional to the logarithm of the number of states in a thermodynamic system. Some writers have identified entropy as being system disorder, but this is not completely true. Entropy of information was first defined by Shannon in 1949 and it is applied to many physical events. Entropy has been used for describing the complexity of the magnetic wave radiated by the line in this paper. Furthermore, the magnetic waves’ spectral and amplitude coefficient of variation (CV were obtained using a multiresolution wavelet algorithm which measures data distribution dispersion. It is a dimensionless number allowing the variation of magnetic radiated data having significantly different mean values to be compared to a 60 Hz pure magnetic wave as reference.

  12. Assessment of microsatellites in estimating inter- and intraspecific variation among Neotropical Crocodylus species.

    Science.gov (United States)

    Bashyal, A; Gross, B A; Venegas-Anaya, M; Lowrance, F; Densmore Iii, L D

    2014-01-01

    We tested microsatellites that were developed for the saltwater crocodile (Crocodylus porosus) for cross-species amplification and to provide an estimate of inter- and intraspecific variation among four species of Neotropical crocodiles (C. rhombifer, C. intermedius, C. acutus, and C. moreletii). Our results indicated that with the exception of 2 loci in C. intermedius, all 10 microsatellite loci were successfully amplified in the 4 species, producing a set of variably sized alleles that ranged in number between 2 and 14 alleles per locus. Similarly, private alleles (i.e., unique alleles) also were reported in all 4 species for at least 3 loci. The mean observed and expected heterozygosities (averaged across species for all 10 loci combined) ranged from 0.39 to 0.77 and from 0.44 to 0.78, respectively. In addition to this, we evaluated these microsatellites in 2 populations of C. acutus and C. moreletii to assess their utility in estimating intraspecific levels of polymorphisms. These microsatellites also showed considerable allelic variation in population level analysis. The set of 10 microsatellite loci in our study had the potential to be used as a tool in population and conservation genetic studies of Neotropical crocodiles. PMID:25117304

  13. A Control Variate Method for Probabilistic Performance Assessment. Improved Estimates for Mean Performance Quantities of Interest

    Energy Technology Data Exchange (ETDEWEB)

    MacKinnon, Robert J.; Kuhlman, Kristopher L

    2016-05-01

    We present a method of control variates for calculating improved estimates for mean performance quantities of interest, E(PQI) , computed from Monte Carlo probabilistic simulations. An example of a PQI is the concentration of a contaminant at a particular location in a problem domain computed from simulations of transport in porous media. To simplify the presentation, the method is described in the setting of a one- dimensional elliptical model problem involving a single uncertain parameter represented by a probability distribution. The approach can be easily implemented for more complex problems involving multiple uncertain parameters and in particular for application to probabilistic performance assessment of deep geologic nuclear waste repository systems. Numerical results indicate the method can produce estimates of E(PQI)having superior accuracy on coarser meshes and reduce the required number of simulations needed to achieve an acceptable estimate.

  14. Sensitivity of hydrological performance assessment analysis to variations in material properties, conceptual models, and ventilation models

    International Nuclear Information System (INIS)

    The Yucca Mountain Site Characterization Project is studying Yucca Mountain in southwestern Nevada as a potential site for a high-level nuclear waste repository. Site characterization includes surface- based and underground testing. Analyses have been performed to support the design of an Exploratory Studies Facility (ESF) and the design of the tests performed as part of the characterization process, in order to ascertain that they have minimal impact on the natural ability of the site to isolate waste. The information in this report pertains to sensitivity studies evaluating previous hydrological performance assessment analyses to variation in the material properties, conceptual models, and ventilation models, and the implications of this sensitivity on previous recommendations supporting ESF design. This document contains information that has been used in preparing recommendations for Appendix I of the Exploratory Studies Facility Design Requirements document

  15. Estimating the Robustness of Composite CBA and MCDA Assessments by Variation of Criteria Importance Order

    DEFF Research Database (Denmark)

    Jensen, Anders Vestergaard; Barfod, Michael Bruhn; Leleur, Steen

    Abstract This paper discusses the concept of using rank variation concerning the stakeholder prioritising of importance criteria for exploring the sensitivity of criteria weights in multi-criteria analysis (MCA). Thereby the robustness of the MCA-based decision support can be tested. The analysis...... described is based on the fact that when using MCA as a decision-support tool, questions often arise about the weighting (or prioritising) of the included criteria. This part of the MCA is seen as the most subjective part and could give reasons for discussion among the decision makers or stakeholders....... Furthermore, the relative weights can make a large difference in the resulting assessment of alternatives (Hobbs and Meier 2000). Therefore it is highly relevant to introduce a procedure for estimating the importance of criteria weights. This paper proposes a methodology for estimating the robustness of...

  16. Office workers' objectively assessed total and prolonged sitting time: Individual-level correlates and worksite variations.

    Science.gov (United States)

    Hadgraft, Nyssa T; Healy, Genevieve N; Owen, Neville; Winkler, Elisabeth A H; Lynch, Brigid M; Sethi, Parneet; Eakin, Elizabeth G; Moodie, Marj; LaMontagne, Anthony D; Wiesner, Glen; Willenberg, Lisa; Dunstan, David W

    2016-12-01

    Sedentary behavior is highly prevalent in office-based workplaces; however, few studies have assessed the attributes associated with this health risk factor in the workplace setting. This study aimed to identify the correlates of office workers' objectively-assessed total and prolonged (≥ 30 min bouts) workplace sitting time. Participants were 231 Australian office workers recruited from 14 sites of a single government employer in 2012-13. Potential socio-demographic, work-related, health-related and cognitive-social correlates were measured through a self-administered survey and anthropometric measurements. Associations with total and prolonged workplace sitting time (measured with the activPAL3) were tested using linear mixed models. Worksites varied significantly in total workplace sitting time (overall mean [SD]: 79% [10%] of work hours) and prolonged workplace sitting time (42% [19%]), after adjusting for socio-demographic and work-related characteristics. Organisational tenure of 3-5 years (compared to tenure > 5 years) was associated with more time spent in total and prolonged workplace sitting time, while having a BMI categorised as obese (compared to a healthy BMI) was associated with less time spent in total and prolonged workplace sitting time. Significant variations in sitting time were observed across different worksites of the same employer and the variation remained after adjusting for individual-level factors. Only BMI and organisational tenure were identified as correlates of total and prolonged workplace sitting time. Additional studies are needed to confirm the present findings across diverse organisations and occupations. PMID:27413681

  17. Genetic variation of Melia azedarach in community forests of West Java assessed by RAPD

    Directory of Open Access Journals (Sweden)

    YULIANTI

    2011-04-01

    Full Text Available Yulianti, Siregar IZ, Wijayanto N, Tapa Darma IGK, Syamsuwida D (2011 Genetic variation of Melia azedarach in community forests of West Java assessed by RAPD. Biodiversitas 12: 64-69. Melia azedarach L. or mindi (local name is one of the widely planted exotic species in Indonesia, mostly found in community forests in West Java. However, improving and increasing the productivity of mindi commmunity plantation in West Java requires information on patterns of existing genetic diversity. The present work was aimed at estimating the genetic variation of mindi by using RAPD markers. Outcome of the activities was to propose appropriate conservation and management strategies of genetic resources in order to support the establishment of seed sources. Six populations of mindi plantation in the community forests were chosen for this research, i.e Sukaraja (Bogor-1, Megamendung (Bogor-2, Bandung, Purwakarta, Sumedang and Kuningan. Five primers (OPA-07, OPY-13, OPY-16, OPA-09 and OPO-05 producing reproducible bands were analysed for 120 selected mother trees in total, in which 20 trees per locality were sampled. Data were analysed using Popgene ver 1.31, NTSYS 2.02 and GenAlEx 6.3. Based on the analysis, the observed number of alleles per locus ranging from 1.43 to 1.60, and percentage of polymorphic loci (PPL ranging from 43.33 to 60.00.%. The levels of genetic variation were considered as moderate for all populations (He range from 0.1603 to 0.1956 and the the mean level of genetic diversity between population (Gst was 0.3005. Cluster analysis and Principal Coordinates showed three main groups, the first group consists of 4 populations i.e Bandung, Kuningan, Purwakarta and Megamendung, the second was Sukaraja and the third was Sumedang. Based on Analysis of Molecular Variance (AMOVA, the Percentages of Molecular Variance within population (69% is higher than that of between populations (31%. The moderate level of genetic variation in the community

  18. Multi-variate flood damage assessment: a tree-based data-mining approach

    Directory of Open Access Journals (Sweden)

    B. Merz

    2013-01-01

    Full Text Available The usual approach for flood damage assessment consists of stage-damage functions which relate the relative or absolute damage for a certain class of objects to the inundation depth. Other characteristics of the flooding situation and of the flooded object are rarely taken into account, although flood damage is influenced by a variety of factors. We apply a group of data-mining techniques, known as tree-structured models, to flood damage assessment. A very comprehensive data set of more than 1000 records of direct building damage of private households in Germany is used. Each record contains details about a large variety of potential damage-influencing characteristics, such as hydrological and hydraulic aspects of the flooding situation, early warning and emergency measures undertaken, state of precaution of the household, building characteristics and socio-economic status of the household. Regression trees and bagging decision trees are used to select the more important damage-influencing variables and to derive multi-variate flood damage models. It is shown that these models outperform existing models, and that tree-structured models are a promising alternative to traditional damage models.

  19. Assessment of Cost Variation in Solid and Hollow Floor Construction in Lagos State

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    Oluwaseun Sunday Dosumu

    2013-12-01

    Full Text Available The differences in construction methods between different forms of slabs construction tend to result into variation in the cost of the slabs for any building project. Thus, this study aims at assessing the variation in construction cost among various construction methods available for hollow and solid floors in construction projects within Lagos State. The research design for this study was a survey design approach and the population of the study are active professionals (Architects, Civil Engineers, Builders, Quantity Surveyors, Consultant and contractors because they are the major participants in the construction activities of the construction industry in Lagos State, Nigeria. The research is based on 46 returned questionnaires out of the 60 that was administered. The data from the questionnaires were analyzed using descriptive tools such as frequencies, percentage and mean values. The hypotheses were tested with paired sample t-test and it was found that the system or method of slab construction well known to the respondents is cast in situ, precast and semi-precast. The study also shows that the cost of in-situ solid slabs are higher than that of hollow slab which is an indication that solid slab construction is more expensive than hollow slab construction provided the hollow slab is a one-way hollow floor and not waffle floor. In pre cast solid slab construction the cost of transportation of units to sites, cost of expertise required in the construction process and the cost of fabrication off site are the three highest and most expensive aspects of precast solid slab while cost of erection and placement and the cost of grouting and topping if required are less expensive. Therefore there is difference in the cost of construction between the solid and hollow slabs but the difference is not appreciable. The study's major recommendation is that, adequate and careful analysis must be done in the choice of floor system being adopted for any

  20. An Assessment of Variation in Active Ingredients of Ampucare from Different Zones of India

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    Naveen Pathak

    2010-04-01

    Full Text Available The present study was designed to assess the variation in curcumin content of Curcuma longa rhizome and total polyphenols in Azadirachta indica bark samples procured from different zones of India. Physico-chemical tests such as total ash, acid insoluble ash, alcohol soluble extractive, water soluble extractive, volatile oil content etc. were also determined. A slight variation was seen in the bark samples of Azadirachta indica. Total ash ranged from 4.25±0.15 (East zone to 5.57±0.20 (Central zone whereas acid insoluble ash ranged from 0.80±0.07 (East zone to 1.52±0.06 (Central zone. Alcohol soluble extractive value of East zone sample was found to be more than 4 times higher 16.95±0.80 than that of central zone 3.85±0.12, where lowest value was recorded. Water soluble extractive value was also found to be highest in East zone sample 17.80±1.10 which was 2 times more than that of Central zone sample 8.45±0.15. This variation may be due to variation in climatic conditions, soil type, pollution stress etc. All the results were within the limits as given in The Ayurvedic Pharmacopoeia of India. Total Polyphenols ranged from 190.0 mgGAE/g of dry weight (Central zone to 510.0 mgGAE/g of dry weight (East zone. All the samples were found to be rich in total polyphenols. In Curcuma longa samples, Total ash ranged from 3.10±0.20 (South zone to 4.80±0.25 (North zone whereas acid insoluble ash ranged from 0.55±0.04 (South zone to 1.24±0.06 (North zone. Alcohol soluble extractive value was found to be highest in South zone sample 14.80±0.30 which was found to be more than 3 times higher than that of central zone 4.28±0.19 where lowest value was recorded. Water soluble extractive value was also found to be highest in West zone sample 12.55±0.69 and lowest in Central zone sample 8.90±0.37. Volatile oil ranged from 3.50±0.21 North zone sample to 5.50±0.20 South zone sample, where highest volatile oil was recovered. All the results were within

  1. Pesticide Residues in Bovine Milk in Punjab, India: Spatial Variation and Risk Assessment to Human Health.

    Science.gov (United States)

    Bedi, J S; Gill, J P S; Aulakh, R S; Kaur, Prabhjit

    2015-08-01

    In the present study, gas chromatographic analysis of pesticide residues in bovine milk (n = 312) from Punjab, India, showed chlorpyrifos, DDT, and γ-HCH as the predominant contaminants. In addition, the presence of β-endosulfan, endosulfan suphate, cypermethrin, cyhalothrin, fenvalerate, deltamethrin, malathion, profenofos, and ethion was reported in milk samples. In this study, it was observed that 12 milk samples exceeded the maximum residue limits (MRLs) for γ-HCH (lindane), 18 for DDT and chlorpyrifos, and 1 sample each for endosulfan, cypermethrin, and profenophos. In India, DDT is still permitted for a malaria control program, which may be the plausible reason for its occurrence in milk samples. The spatial variation for presence of pesticide residues in milk indicated greater levels in cotton-growing areas of Punjab. At current levels of pesticide residues in bovine milk, the human health risk assessment in terms of noncancer and cancer hazard was calculated based on both lower-bound [LB (mean residue levels)] and upper-bound [UP (95th percentile level)] limits. It was noticed that cancer and noncancer risk were within United States Environmental Protection Agency prescribed limits for both adults and children at the LB, but children were being exposed to greater risk for DDT and HCH at the 95th-percentile UB level. PMID:26008642

  2. Parameter variation and scenario analysis in impact assessments of emerging energy technologies

    Science.gov (United States)

    Breunig, Hanna Marie

    There is a global need for energy technologies that reduce the adverse impacts of societal progress and that address today's challenges without creating tomorrow's problems. Life cycle impact assessment (LCIA) can support technology developers in achieving these prerequisites of sustainability by providing a systems perspective. However, modeling the early-stage scale up and impacts of technology systems may lead to unreliable or incomplete results due to a lack of representative technical, spatial, and temporal data. The goal of this dissertation is to support the acceleration of clean energy technology development by providing information about the regional variation of impacts and benefits resulting from plausible deployment scenarios. Three emerging energy technologies are selected as case studies: (1) brine management for carbon dioxide sequestration; (2) carbon dioxide capture, utilization, and sequestration; (3) stationary fuel cells for combined heat and power in commercial buildings. In all three case studies, priority areas are identified where more reliable data and models are necessary for reducing uncertainty, and vital information is revealed on how impacts vary spatially and temporally. Importantly, moving away from default technology and waste management hierarchies as a source of data fosters goal-driven systems thinking which in turn leads to the discovery of technology improvement potentials.

  3. A new approach for the assessment of stochastic variation: analysis of behavioural response in blue mussel ( Mytilus edulis L.)

    Science.gov (United States)

    Lajus, D. L.; Sukhotin, A. A.

    1998-06-01

    One of the most effective techniques for evaluating stress is the analysis of developmental stability, measured by stochastic variation based particularly on fluctuating asymmetry, i.e. a variance in random deviations from perfect bilateral symmetry. However, the application of morphological methods is only possible when an organism lives under testing conditions during a significant part of its ontogenesis. Contrary to morphological characters, behavior can change very fast. Consequently, methods based on behavioural characters may have advantages over more traditional approaches. In this study we describe the technique of assessing stochastic variation, using not morphological, but behavioural characters. To measure stochastic variation of behavioural response, we assessed the stability of the isolation reaction of blue mussel Mytilus edulis at regular changes of salinity. With increasing temperature from +12°C to +20°C stochastic variation of the isolation reaction increased, which is a common response to change of environmental conditions. In this way, we have developed a method of assessing stochastic variation of behavioural response in molluscs. This method may find a great range of applications, because its usage does not require keeping animals in tested conditions for a long time.

  4. Prospective radiological dose assessment. Amersham plc (Amersham site) variation application December 1998

    International Nuclear Information System (INIS)

    Amersham plc (previously Nycomed-Amersham plc) submitted an application to the Environment Agency in December 1998 for a variation to their radioactive waste discharge authorisations granted under the Radioactive Substances Act 1993. The application requested a reduction in the discharge limits for certain radionuclides and no change for the remaining radionuclides. Amersham plc undertook a further review of their discharge requirements and submitted a new assessment for revised limits in January 2001. This report provides an assessment of the radiological implications of discharges at these revised limits requested by Amersham plc and the limits proposed by the Agency. It has been prepared by the National Compliance Assessment Service at the request of Thames Region to support their determination of the application. Four candidate critical groups were identified who could be exposed to discharges from the Amersham site: 1) Sewage workers at the Maple Lodge sewage works who might be exposed to external radiation from discharges contained within sewage and inadvertently inhale or ingest sewage. 2) Anglers on the Grand Union Canal who eat a small proportion of their annual catch of freshwater fish, who drink water abstracted solely from the River Colne and eat vegetables irrigated by water from the canal. 3) Persons living closest to site who eat locally produced food. 4) Dog walkers living near to site who eat locally produced food. For continuous discharges at the Agency's proposed annual limits, the highest dose of 160 μSv/y is predicted to be received by infants who live closest to the site and eat locally produced food. Therefore, this has been identified as the critical group. Children and adults living at the same location and eating locally produced food receive doses of 140 μSv/y and 130 μSv/y respectively. The critical group dose is less than the source constraint of 300 μSv/y. The dose is dominated by direct radiation from the site (110 μSv/y) and the

  5. Genetic variation of Lymnaea stagnalis tolerance to copper: A test of selection hypotheses and its relevance for ecological risk assessment

    International Nuclear Information System (INIS)

    The use of standardized monospecific testing to assess the ecological risk of chemicals implicitly relies on the strong assumption that intraspecific variation in sensitivity is negligible or irrelevant in this context. In this study, we investigated genetic variation in copper sensitivity of the freshwater snail Lymnaea stagnalis, using lineages stemming from eight natural populations or strains found to be genetically differentiated at neutral markers. Copper-induced mortality varied widely among populations, as did the estimated daily death rate and time to 50% mortality (LT50). Population genetic divergence in copper sensitivity was compared to neutral differentiation using the QST-FST approach. No evidence for homogenizing selection could be detected. This result demonstrates that species-level extrapolations from single population studies are highly unreliable. The study provides a simple example of how evolutionary principles could be incorporated into ecotoxicity testing in order to refine ecological risk assessment. - Highlights: • Genetic variation in copper tolerance occurs between Lymnaea stagnalis populations. • We used the QST-FST approach to test evolutionary patterns in copper tolerance. • No evidence for uniform selection was found. • Results suggest that extrapolations to the species level are not safe. • A method is proposed to refine ecological risk assessment using genetic parameters. - Genetic variation in copper tolerance occurs in Lymnaea stagnalis. A method is proposed for considering evolutionary parameters in ecological risk assessment

  6. Assessing the impact of climate variability and human activity to streamflow variation

    Directory of Open Access Journals (Sweden)

    J. Chang

    2015-06-01

    Full Text Available Water resources in river systems have been changing under the impacts of both climate variability and human activities. Assessing the respective impacts on decadal streamflow variation is important for water resources management. By using an elasticity-based method, calibrated TOPMODEL and VIC hydrologic models, we have quantitatively isolated the relative contributions that human activity and climate variability made to decadal streamflow changes in Jinhe basin located in northwest of China. This is an important watershed of Shaanxi Province that supplies drinking water for a population of over 6 million. The results from the three methods show that both human activity and climatic differences can have major effects on catchment streamflow, and the estimates of climate variability impacts from the hydrological models are similar to those from the elasticity-based method. Compared with the baseline period of 1960–1970, streamflow greatly decreased during 2001–2010. The change impacts of human activity and climate variability in 2001–2010 were about 83.5 and 16.5% of the total reduction respectively when averaged over the three methods. The maximum contribution value of human activity was appeared in 1981–1990 due to the effects of soil and water conservation measures and irrigation water withdrawal, which was 95, 112.5 and 92.4% from TOPMODEL, VIC model and elasticity-based method respectively. The maximum value of the aridity index (E0/P was 1.91 appeared in 1991–2000. Compared with 1960–1970 baseline period, climate variability made the greatest contributions reduction in 1991–2000, which was 47.4, 43.9 and 29.9% from TOPMODEL, VIC model and elasticity-based method respectively. We emphasized various source of errors and uncertainties that may occurre in the hydrological model (parameter and structural uncertainty and elasticity-based method (model parameter in climate change impact studies.

  7. Assessing the impact of climate variability and human activity to streamflow variation

    Science.gov (United States)

    Chang, J.; Zhang, H.; Wang, Y.; Zhu, Y.

    2015-06-01

    Water resources in river systems have been changing under the impacts of both climate variability and human activities. Assessing the respective impacts on decadal streamflow variation is important for water resources management. By using an elasticity-based method, calibrated TOPMODEL and VIC hydrologic models, we have quantitatively isolated the relative contributions that human activity and climate variability made to decadal streamflow changes in Jinhe basin located in northwest of China. This is an important watershed of Shaanxi Province that supplies drinking water for a population of over 6 million. The results from the three methods show that both human activity and climatic differences can have major effects on catchment streamflow, and the estimates of climate variability impacts from the hydrological models are similar to those from the elasticity-based method. Compared with the baseline period of 1960-1970, streamflow greatly decreased during 2001-2010. The change impacts of human activity and climate variability in 2001-2010 were about 83.5 and 16.5% of the total reduction respectively when averaged over the three methods. The maximum contribution value of human activity was appeared in 1981-1990 due to the effects of soil and water conservation measures and irrigation water withdrawal, which was 95, 112.5 and 92.4% from TOPMODEL, VIC model and elasticity-based method respectively. The maximum value of the aridity index (E0/P) was 1.91 appeared in 1991-2000. Compared with 1960-1970 baseline period, climate variability made the greatest contributions reduction in 1991-2000, which was 47.4, 43.9 and 29.9% from TOPMODEL, VIC model and elasticity-based method respectively. We emphasized various source of errors and uncertainties that may occurre in the hydrological model (parameter and structural uncertainty) and elasticity-based method (model parameter) in climate change impact studies.

  8. Assessing the contribution of climate variability and human activity to runoff variation in Jinghe basin

    Science.gov (United States)

    Wang, Yimin; wei, Jie

    2015-04-01

    Hydrological processes in river systems have been changing under the impacts of both climate variability and human activities. Assessing the respective impacts on decadal streamflow variation is important for water resources management. By using an elasticity-based method, a calibrated TOPMODEL and VIC model, we have quantitatively isolated the relative contributions that human activities and climate change made to decadal streamflow changes in Jinhe basin located in northwest of China. This is an important watershed of Shaanxi Province that supplies drinking water for population over 6 million. The results from the three methods show that both human activities and climatic differences can have major effects on catchment streamflow, and the estimates of climate change impacts from the hydrological models are similar to those from the elasticity-based method. Compared with the baseline period of 1960-1970, streamflow greatly decreased during 2001-2010. The change impacts of ∆QH and ∆QC in 2001-2010 were about 83.5% and 16.5% of the total reduction, and the contribution ratios of ∆QH and ∆QC during 1971-2010 are 78.3% and 21.7% respectively when averaged over the three methods. The maximum contribution value of human activities was appeared in 1981-1990 due to the effects of soil and water conservation measures and irrigation water withdrawal, which was 95%, 112.5% and 92.4% from TOPMODEL, VIC model and elasticity-based method respectively. The maximum value of the moisture index (E0/ P) was 1.91 appeared in 1991-2000. Compared with 1960-1970 baseline period, climate change made the greatest contributions reduction in 1991-2000, which was 47.4%, 43.9% and 29.9% from TOPMODEL, VIC model and elasticity-based method respectively. We analyzed the source of errors and uncertainties which may occur in the different approaches.

  9. Geospatial approach for assessment of biophysical vulnerability to agricultural drought and its intra-seasonal variations.

    Science.gov (United States)

    Sehgal, Vinay Kumar; Dhakar, Rajkumar

    2016-03-01

    The study presents a methodology to assess and map agricultural drought vulnerability during main kharif crop season at local scale and compare its intra-seasonal variations. A conceptual model of vulnerability based on variables of exposure, sensitivity, and adaptive capacity was adopted, and spatial datasets of key biophysical factors contributing to vulnerability were generated using remote sensing and GIS for Rajasthan State of India. Hazard exposure was based on frequency and intensity of gridded standardized precipitation index (SPI). Agricultural sensitivity was based on soil water holding capacity as well as on frequency and intensity of normalized difference vegetation index (NDVI)-derived trend adjusted vegetation condition index (VCITadj). Percent irrigated area was used as a measure of adaptive capacity. Agricultural drought vulnerability was derived separately for early, mid, late, and whole kharif seasons by composting rating of factors using linear weighting scheme and pairwise comparison of multi-criteria evaluation. The regions showing very low to extreme rating of hazard exposure, drought sensitivity, and agricultural vulnerability were identified at all four time scales. The results indicate that high to extreme vulnerability occurs in more than 50% of net sown area in the state and such areas mostly occur in western, central, and southern parts. The higher vulnerability is on account of non-irrigated croplands, moderate to low water holding capacity of sandy soils, resulting in higher sensitivity, and located in regions with high probability of rainfall deficiency. The mid and late season vulnerability has been found to be much higher than that during early and whole season. Significant correlation of vulnerability rating with food grain productivity, drought recurrence period, crop area damaged in year 2009 and socioeconomic indicator of human development index (HDI) proves the general soundness of methodology. Replication of this methodology

  10. Assessing the impact of climate variability and human activities on streamflow variation

    Science.gov (United States)

    Chang, Jianxia; Zhang, Hongxue; Wang, Yimin; Zhu, Yuelu

    2016-04-01

    Water resources in river systems have been changing under the impact of both climate variability and human activities. Assessing the respective impact on decadal streamflow variation is important for water resource management. By using an elasticity-based method and calibrated TOPMODEL and VIC hydrological models, we quantitatively isolated the relative contributions that human activities and climate variability made to decadal streamflow changes in the Jinghe basin, located in the northwest of China. This is an important watershed of the Shaanxi province that supplies drinking water for a population of over 6 million people. The results showed that the maximum value of the moisture index (E0/P) was 1.91 and appeared in 1991-2000, and the decreased speed of streamflow was higher since 1990 compared with 1960-1990. The average annual streamflow from 1990 to 2010 was reduced by 26.96 % compared with the multiyear average value (from 1960 to 2010). The estimates of the impacts of climate variability and human activities on streamflow decreases from the hydrological models were similar to those from the elasticity-based method. The maximum contribution value of human activities was 99 % when averaged over the three methods, and appeared in 1981-1990 due to the effects of soil and water conservation measures and irrigation water withdrawal. Climate variability made the greatest contribution to streamflow reduction in 1991-2000, the values of which was 40.4 %. We emphasized various source of errors and uncertainties that may occur in the hydrological model (parameter and structural uncertainty) and elasticity-based method (model parameter) in climate change impact studies.

  11. Effect of diurnal and seasonal temperature variation on Cussac cave ventilation using co2 assessment

    Science.gov (United States)

    Peyraube, Nicolas; Lastennet, Roland; Villanueva, Jessica Denila; Houillon, Nicolas; Malaurent, Philippe; Denis, Alain

    2016-05-01

    Cussac cave was investigated to assess the cave air temperature variations and to understand its ventilation regime. This cave is located in an active karst system in the south west part of France. It has a single entrance and is considered as a cold air trap. In this study, air mass exchanges were probed. Measurements of temperature and Pco2 with a 30-min frequency were made in several locations close to the cave entrance. Speed of the air flow was also measured at the door of cave entrance. Results show that cave air Pco2 varies from 0.18 to 3.33 %. This cave appears to be a CO2 source with a net mass of 2319 tons blown in 2009. Carbon-stable isotope of CO2 (13Cco2) ranges from -20.6 ‰ in cold season to -23.8 ‰ in warm season. Cave air is interpreted as a result of a mix between external air and an isotopically depleted air, coming from the rock environment. The isotopic value of the light member varies through time, from -23.9 to -22.5 ‰. Furthermore, this study ascertains that the cave never stops in communicating with the external air. The ventilation regime is identified. (1) In cold season, the cave inhales at night and blows a little at the warmest hours. However, in warm season, (2) cave blows at night, but (3) during the day, a convection loop takes place in the entrance area and prevents the external air from entering the cave, confirming the cold air trap.

  12. Assessing intraspecific variation in effective dispersal along an altitudinal gradient: a test in two Mediterranean high-mountain plants.

    Directory of Open Access Journals (Sweden)

    Carlos Lara-Romero

    . Our results call for a case-by-case analysis in a wider range of plant taxa and environments to assess the prevalence and magnitude of intraspecific dispersal variation.

  13. An assessment of opportunities to dissect host genetic variation in resistance to infectious diseases in livestock

    OpenAIRE

    Davies, G.; S. Genini; Bishop, S.C.; Giuffra, E

    2009-01-01

    This paper reviews the evidence for host genetic variation in resistance to infectious diseases for a wide variety of diseases of economic importance in poultry, cattle, pig, sheep and Atlantic salmon. Further, it develops a method of ranking each disease in terms of its overall impact, and combines this ranking with published evidence for host genetic variation and information on the current state of genomic tools in each host species. The outcome is an overall ranking of the amenability of ...

  14. Application of the adductome approach to assess intertissue DNA damage variations in human lung and esophagus

    International Nuclear Information System (INIS)

    Methods for determining the differential susceptibility of human organs to DNA damage have not yet been explored to any large extent due to technical constraints. The development of comprehensive analytical approaches by which to detect intertissue variations in DNA damage susceptibility may advance our understanding of the roles of DNA adducts in cancer etiology and as exposure biomarkers at least. A strategy designed for the detection and comparison of multiple DNA adducts from different tissue samples was applied to assess esophageal and peripherally- and centrally-located lung tissue DNA obtained from the same person. This adductome approach utilized LC/ESI-MS/MS analysis methods designed to detect the neutral loss of 2'-deoxyribose from positively ionized 2'-deoxynucleoside adducts transmitting the [M+H]+ > [M+H-116]+ transition over 374 transitions. In the final analyses, adductome maps were produced which facilitated the visualization of putative DNA adducts and their relative levels of occurrence and allowed for comprehensive comparisons between samples, including a calf thymus DNA negative control. The largest putative adducts were distributed similarly across the samples, however, differences in the relative amounts of putative adducts in lung and esophagus tissue were also revealed. The largest-occurring lung tissue DNA putative adducts were 90% similar (n = 50), while putative adducts in esophagus tissue DNA were shown to be 80 and 84% similar to central and peripheral lung tissue DNA respectively. Seven DNA adducts, N2-ethyl-2'-deoxyguanosine (N2-ethyl-dG), 1,N6-etheno-2'-deoxyadenosine (εdA), α-S- and α-R-methyl-γ-hydroxy-1,N2-propano-2'-deoxyguanosine (1,N2-PdG1, 1,N2-PdG2), 3-(2'-deoxyribosyl)-5,6,7,8-tetrahydro-8-hydroxy-pyrimido[1,2-a] purine-(3H)-one (8-OH-PdG) and the two stereoisomers of 3-(2'-deoxyribosyl)-5,6,7,8-tetrahydro-6-hydroxypyrimido[1,2-a] purine-(3H)-one (6-OH-PdG) were unambiguously detected in all tissue DNA samples by

  15. Assessment of BeiDou differential code bias variations from multi-GNSS network observations

    Science.gov (United States)

    Jin, S. G.; Jin, R.; Li, D.

    2016-02-01

    The differential code bias (DCB) of global navigation satellite systems (GNSSs) affects precise ionospheric modeling and applications. In this paper, daily DCBs of the BeiDou Navigation Satellite System (BDS) are estimated and investigated from 2-year multi-GNSS network observations (2013-2014) based on global ionospheric maps (GIMs) from the Center for Orbit Determination in Europe (CODE), which are compared with Global Positioning System (GPS) results. The DCB of BDS satellites is a little less stable than GPS solutions, especially for geostationary Earth orbit (GEO) satellites. The BDS GEO observations decrease the precision of inclined geosynchronous satellite orbit (IGSO) and medium Earth orbit (MEO) DCB estimations. The RMS of BDS satellites DCB decreases to about 0.2 ns when we remove BDS GEO observations. Zero-mean condition effects are not the dominant factor for the higher RMS of BDS satellites DCB. Although there are no obvious secular variations in the DCB time series, sub-nanosecond variations are visible for both BDS and GPS satellites DCBs during 2013-2014. For satellites in the same orbital plane, their DCB variations have similar characteristics. In addition, variations in receivers DCB in the same region are found with a similar pattern between BDS and GPS. These variations in both GPS and BDS DCBs are mainly related to the estimated error from ionospheric variability, while the BDS DCB intrinsic variation is in sub-nanoseconds.

  16. Phonetic variations and sound changes in Hong Kong Cantonese: diachronic review, synchronic study and implications for speech sound assessment.

    Science.gov (United States)

    To, Carol K S; Mcleod, Sharynne; Cheung, Pamela S P

    2015-05-01

    The aim of this article was to describe phonetic variations and sound changes in Hong Kong Cantonese (HKC) to provide speech-language pathologists with information about acceptable variants of standard pronunciations for speech sound assessments. Study 1 examined the pattern of variations and changes based on past diachronic research and historical written records. Nine phonetic variations were found. Five in syllable-initial and syllabic contexts: (1) [n-] → [l-], (2) [ŋ-] → Ø-, (3) Ø- → [ŋ-], (4) [k(w)ɔ-] → [kɔ-], (5) syllabic [ŋ̍] → [m̩]; and four in syllable-final contexts: (6) [-ŋ] → [-n], (7) [-n] → [-ŋ], (8) [-k] → [-t], (9) [-t] → [-k]. Historical records demonstrated the pattern of variation and changes in HKC across time. In study 2, a large-scale synchronic study of speakers of differing ages was undertaken to determine acceptable phonetic variations of HKC for speech sound assessments. In the synchronic study, single-words were elicited from 138 children (10;8-12;4) and 112 adults (18-45 years) who spoke Cantonese and lived in Hong Kong. Synchronic evidence demonstrated five acceptable variants in syllable-initial and syllabic contexts: (1) [n-] → [l-], (2) [ŋ-] → Ø-, (3) Ø- → [ŋ-], (4) [k(w)ɔ-] → [kɔ-] and (5) syllabic [ŋ̍] → [m̩] and four incomplete sound changes in syllable-final contexts: (6) [-ŋ] → [-n], (7) [-n] → [-ŋ], (8) [-k] → [-t] and (9) [-t] → [-k]. The incomplete sound changes may still be accepted as variants in speech sound assessments unless related speech problems are indicated. PMID:25651195

  17. Assessment of variations in thermal cycle life data of thermal barrier coated rods

    Science.gov (United States)

    Hendricks, R. C.; Mcdonald, G.

    1981-01-01

    The reported study had the purpose to examine variations in cyclic life and in adhesive/cohesive coating strength. Possible effects of heating rate, stress reversal, temperature level, and ceramic deposition methods on coating life were also investigated. Life cycle data for 22 thermal barrier coated rods were examined and found to be statistically modeled by normal or log-normal distributions. The sample mean was 1330 cycles with a standard deviation of 520 cycles. Adhesive/cohesive pulloff strength data for 20 thermal barrier coated flat head piston specimens were taken. The average pulloff stress was 9 MPa with a standard deviation of 4.2 MPa. It was found that variations in heating rate can produce significant variations in the life cycle data.

  18. Assessment of the natural variation of low abundant metabolic proteins in soybean seeds using proteomics

    Science.gov (United States)

    Using two-dimensional polyacrylamide gel electrophoresis and mass spectrometry, we investigated the distribution of the low abundant proteins that are involved in soybean seed development in four wild and twelve cultivated soybean genotypes. We found proteomic variation of these proteins within and...

  19. Assessment of the biological variation of plasma tissue inhibitor of metalloproteinases-1

    DEFF Research Database (Denmark)

    2008-01-01

    [R] 1), then repeated in May 2005 (R2) and May 2006 (R3) in the same group of individuals. TIMP-1 levels were determined by the MAC15 ELISA assay and with the Abbott ARCHITECT i2000 Immunoanalyzer. 2: Circadian variation was evaluated in plasma collected 7 times within a 24-hour period (n=16). 3...

  20. Assessment of inter- and intra-cultivar variations in olive using SSR markers

    Directory of Open Access Journals (Sweden)

    Ahmet Ipek

    2012-10-01

    Full Text Available Olive (Olea europaea L. production in the world has been made by using many cultivars, and the genetic uniformity of commercial cultivars is important for standard olive oil and table olive production. The genetic variation among and within commonly cultivated olive cultivars in Turkey was analyzed using SSR markers. A total of 135 leaf samples were collected from 11 commonly cultivated olive cultivars from 11 provinces in four geographical regions of Turkey. Seven SSR primer pairs generated 46 SSR markers, and the number of SSR markers per primer pair ranged from 4 (UDO-14 to 9 (GAPU-89 with an average of 6.57. This high level of SSR polymorphism suggests that olive production in Turkey has been made using genetically diverse olive cultivars and this high level of genetic variation is probably due to the location of Turkey in the center of the origin of olive. The UPGMA dendrogram, developed to visualize the estimated genetic relationships among the 135 samples, demonstrated that the clustering of olive cultivars was not based on geographical regions of cultivation. Presence of genetic variation was detected within a nationwide grown Turkish olive cultivar, called 'Gemlik'. Olive growers successfully discriminated olive cultivars with distinct morphological and pomological characters. However, there was some confusion about the identification of cultivars with similar phenotypic traits. To prevent misidentification of olive cultivars and to minimize intra-cultivar variation, certified propagation materials which were characterized using DNA based molecular markers should be used during the establishment of new olive orchards.

  1. Diurnal variations in the outcomes of instrumented gait and quiet standing balance assessments and their association with falls history

    International Nuclear Information System (INIS)

    One in three adults aged over 65 falls every year, resulting in enormous costs to society. Incidents of falling vary with time of day, peaking in the early morning. The aim of this study was to determine if the ability of instrumented gait and balance assessments to discriminate between participants based on their falls history varies diurnally. Body-worn sensors were used during a 3 m gait assessment and a series of quiet standing balance tests. Each assessment was performed four times during a single day under supervised conditions in the participant's homes. 40 adults aged over 60 years (19 fallers) participated in this study. A range of parameters were derived for each assessment, and the ability of each parameter to discriminate between fallers and non-fallers at each recording time was examined. The effect of falls history on single support time varied significantly with recording time, with a significantly reduced single support time observed at the first and last recording session of the day. Differences were observed between fallers and non-fallers for a range of other gait parameters; however, these effects did not vary with assessment time. The quiet standing assessments examined in this study revealed significant variations with falls history; however, the sensitivity of the examined quiet standing assessments to falls risk does not appear to be time dependent. These results indicate that, with the exception of single support time, the association of gait and quiet standing balance parameters with falls risk does not vary diurnally. (paper)

  2. Diurnal variation of tension-type headache intensity and exacerbation: An investigation using computerized ecological momentary assessment

    Directory of Open Access Journals (Sweden)

    Kikuchi Hiroe

    2012-09-01

    Full Text Available Abstract Backgrounds Tension-type headache is a common psychosomatic disease. However, diurnal variation of headache is yet to be clarified, perhaps due to the lack of an appropriate method to investigate it. Like other painful diseases, it would be helpful to know if there is diurnal variation in tension-type headaches, both for managing headaches and understanding their pathophysiology. The aim of this study was to determine if there is diurnal variation in the intensity and exacerbation of tension-type headache. Methods Patients (N = 31 with tension-type headache recorded for one week their momentary headache intensity several times a day and their acute headache exacerbations using a watch-type computer as an electronic diary (computerized ecological momentary assessment. Multilevel modeling was used to test the effects of time of day on momentary headache intensity and on the occurrence of acute exacerbations. Results A significant diurnal variation in momentary headache intensity was shown (P = 0.0005, with the weakest headaches in the morning and a peak in the late afternoon. A between-individual difference in the diurnal pattern was suggested. On-demand medication use was associated with a different diurnal pattern (P = 0.025, suggesting that headache intensity decreases earlier in the evening in subjects who used on-demand medication, while headache subtype, prophylactic medication use, and sex were not associated with the difference. The occurrence of acute headache exacerbation also showed a significant diurnal variation, with a peak after noon (P = 0.0015. Conclusions Tension-type headache was shown to have a significant diurnal variation. The relation to pathophysiology and psychosocial aspects needs to be further explored.

  3. Assessment of Morphometric and Genetic Variation an Three Freshwater Fish Species of the Genus Garra (Osteichthyes: Cyprinidae

    Directory of Open Access Journals (Sweden)

    Arulraj DHINAKARAN

    2011-03-01

    Full Text Available The present study evaluated the patterns of morphometric and genetic variation using RAPD-PCR techniques for the first time on three species of Garra, viz. G. mullya, G. kalakadensis and G. gotyla stenorhynchus, collected from various river basins of South-India. The results of morphological analysis revealed that G. mullya and G. kalakadensis hold many similar characters compared to the other congener, G. gotyla stenorhynchus. However, the G. gotyla stenorhynchus fish species exhibited distinct variation in the morphological characters such as snout length, pre-nasal length, inter-nasal width, gap width, lower jaw to isthmus, head depth at pupil, dorsal fin length and disc width from the other two species of Garra. However, certain morphometric characters overlapped. Hence the RAPD finger printing was used to assess the levels of genetic variation in Garra spp. using RAPD-PCR technique. A total of 72 reliable fragments were detected using 10 Operon primers, ranging from 2600 molecular weight to 3100. The shared RAPD fragments found in both G. mullya and G. kalakadensis with fixed frequencies were observed with all the investigated primers, implying their genetically closer relationship. However, the similarity index observed for G. gotyla stenorhynchus was less with the other two species specifying a genetically distant link. The present investigation thus contribute to the knowledge on morphological and genetic variation in these three Garra species.

  4. Assessment of Morphometric and Genetic Variation in Three Freshwater Fish Species of the Genus Garra (Osteichthyes: Cyprinidae

    Directory of Open Access Journals (Sweden)

    Arulraj DHINAKARAN

    2011-03-01

    Full Text Available The present study evaluated the patterns of morphometric and genetic variation using RAPD-PCR techniques for the first time on three species of Garra, viz. G. mullya, G. kalakadensis and G. gotyla stenorhynchus, collected from various river basins of South-India. The results of morphological analysis revealed that G. mullya and G. kalakadensis hold many similar characters compared to the other congener, G. gotyla stenorhynchus. However, the G. gotyla stenorhynchus fish species exhibited distinct variation in the morphological characters such as snout length, pre-nasal length, inter-nasal width, gap width, lower jaw to isthmus, head depth at pupil, dorsal fin length and disc width from the other two species of Garra. However, certain morphometric characters overlapped. Hence the RAPD finger printing was used to assess the levels of genetic variation in Garra spp. using RAPD-PCR technique. A total of 72 reliable fragments were detected using 10 Operon primers, ranging from 2600 molecular weight to 3100. The shared RAPD fragments found in both G. mullya and G. kalakadensis with fixed frequencies were observed with all the investigated primers, implying their genetically closer relationship. However, the similarity index observed for G. gotyla stenorhynchus was less with the other two species specifying a genetically distant link. The present investigation thus contribute to the knowledge on morphological and genetic variation in these three Garra species.

  5. Variations in flood magnitude-effect relations and the implications for flood risk assessment and river management

    Science.gov (United States)

    Hooke, J. M.

    2015-12-01

    In spite of major physical impacts from large floods, present river management rarely takes into account the possible dynamics and variation in magnitude-impact relations over time in flood risk mapping and assessment nor incorporates feedback effects of changes into modelling. Using examples from the literature and from field measurements over several decades in two contrasting environments, a semi-arid region and a humid-temperate region, temporal variations in channel response to flood events are evaluated. The evidence demonstrates how flood physical impacts can vary at a location over time. The factors influencing that variation on differing timescales are examined. The analysis indicates the importance of morphological changes and trajectory of adjustment in relation to thresholds, and that trends in force or resistance can take place over various timescales, altering those thresholds. Sediment supply can also change with altered connectivity upstream and changes in state of hillslope-channel coupling. It demonstrates that seasonal timing and sequence of events can affect response, particularly deposition through sediment supply. Duration can also have a significant effect and modify the magnitude relation. Lack of response or deposits in some events can mean that flood frequency using such evidence is underestimated. A framework for assessment of both past and possible future changes is provided which emphasises the uncertainty and the inconstancy of the magnitude-impact relation and highlights the dynamic factors and nature of variability that should be considered in sustainable management of river channels.

  6. Assessing the Impact of Socioeconomic Variables on Small Area Variations in Suicide Outcomes in England

    Directory of Open Access Journals (Sweden)

    Peter Congdon

    2012-12-01

    Full Text Available Ecological studies of suicide and self-harm have established the importance of area variables (e.g., deprivation, social fragmentation in explaining variations in suicide risk. However, there are likely to be unobserved influences on risk, typically spatially clustered, which can be modeled as random effects. Regression impacts may be biased if no account is taken of spatially structured influences on risk. Furthermore a default assumption of linear effects of area variables may also misstate or understate their impact. This paper considers variations in suicide outcomes for small areas across England, and investigates the impact on them of area socio-economic variables, while also investigating potential nonlinearity in their impact and allowing for spatially clustered unobserved factors. The outcomes are self-harm hospitalisations and suicide mortality over 6,781 Middle Level Super Output Areas.

  7. An assessment of CETP sequence variation in relation to cognitive decline and dementia risk

    OpenAIRE

    Reynolds, Chandra A; Gatz, Margaret; Pedersen, Nancy L; Prince, Jonathan A

    2011-01-01

    The gene encoding the cholesteryl ester transfer protein (CETP) plays an integral role in lipid metabolism. We evaluated common genetic variation spanning CETP for association with cognitive decline as well as incident and prevalent dementia and Alzheimer disease risk. Data from four population-based twin studies and a case-control sample were included, encompassing an analysis sample of 1513 dementia cases and 2137 controls with available CETP genotypes and covariates. Memory and perceptual ...

  8. An assessment of variations in mercury deposition to Antarctica over the past 34,000 years

    Institute of Scientific and Technical Information of China (English)

    尹雪斌; 孙立广; 谢周清

    2003-01-01

    We performed a comparison analysis of the variations in Mercury (Hg)concentrations and the precipitation proxies (e. g. , 18 O values and 10 Be concentrations) in the Dome C ice core. The results showed that there were significant correlations between Hg and δ 18 O values, 10 Be concentrations, indicating that the accumulation rate in Dome C is one of the key factors controlling the variations of Hg concentrations in the past 34,000 years, and implying that Hg concentrations in ice core can be used as another reliable proxy of precipitation rate in Antarctica. Based upon the high-resolution δ 18 O values, we estimated the variations in mercury deposition flux to Antarctica over the past 34,000 years. The highest mercury deposition flux is about 3.80 pg cm -2 yr-1 during the Last Glacial Maxium (LGM) as high as 3.5 times of the mercury deposition flux (about 1.08 pg em-2 yr -1 ) in Holocene due to the fluctuations in natural mercury emissions such as the oceanic biological emissions.

  9. Using Acoustics to Determine Eelgrass Bed Distribution and to Assess the Seasonal Variation of Ecosystem Service

    Science.gov (United States)

    Sonoki, Shiori; Shao, Huamei; Morita, Yuka; Minami, Kenji; Shoji, Jun; Hori, Masakazu; Miyashita, Kazushi

    2016-01-01

    Eelgrass beds are an important source of primary production in coastal ecosystems. Understanding seasonal variation in the abundance and distribution of eelgrass is important for conservation, and the objectives of this study were to 1) monitor seasonal variation in eelgrass beds using an acoustic monitoring method (Quantitative echo sounder) and 2) broadly quantify the carbon circulation function. We obtained acoustic data of eelgrass beds in coastal areas north and east of Ikunojima Island. Surveys were conducted nine times over the 3-year period from 2011 to 2013 in order to monitor seasonal variation. Acoustic data were obtained and used to estimate the spatial distribution of eelgrass by geostatistical methods. To determine supporting services, we determined carbon sink and carbon fixation by eelgrass beds using data from the National Research Institute of Fisheries and Environment of Inland Sea (2011). The height and distribution of eelgrass beds were at a maximum in May and at a minimum in November of each year. Distribution trends were different between the north and east areas. Supporting services showed the same patterns throughout the year. The area of distribution was considered to be coincident with the life history of eelgrass. Distribution differed by area and changed yearly due to the effects of bottom characteristics and wind direction. Quantifying the supporting services of eelgrass beds was shown to be useful for managing the conservation of coastal ecosystems. PMID:26954673

  10. Variation in assessment of oxidatively damaged DNA in mononuclear blood cells by the comet assay with visual scoring

    DEFF Research Database (Denmark)

    Forchhammer, Lykke; Bräuner, Elvira Vaclavik; Folkmann, Janne Kjaersgaard;

    2008-01-01

    The comet assay is popular for assessments of genotoxicity, but the comparison of results between studies is challenging because of differences in experimental procedures and reports of DNA damage in different units. We investigated the variation of DNA damage in mononuclear blood cells (MNBCs......) measured by the comet assay with focus on the variation related to alkaline unwinding and electrophoresis time, number of cells scored, as well as the putative benefits of transforming the primary end points to common units by the use of reference standards and calibration curves. Eight experienced...... conclusion, our results indicate that inter-investigator difference in scoring is a strong determinant of DNA damage levels measured by the comet assay....

  11. Multi-variate flood damage assessment: a tree-based data-mining approach

    OpenAIRE

    B. Merz; H. Kreibich; Lall, U.

    2013-01-01

    The usual approach for flood damage assessment consists of stage-damage functions which relate the relative or absolute damage for a certain class of objects to the inundation depth. Other characteristics of the flooding situation and of the flooded object are rarely taken into account, although flood damage is influenced by a variety of factors. We apply a group of data-mining techniques, known as tree-structured models, to flood damage assessment. A very comprehensive data...

  12. Assessment of the magnitude of geographical variations in the duration of non-work-related sickness absence by individual and contextual factors

    OpenAIRE

    Isabel Torá-Rocamora; José Miguel Martínez; David Gimeno; Constança Alberti; Josefina Jardí; Rafael Manzanera; Benavides, Fernando G.; George Delclos

    2015-01-01

    Objective: To examine variation in the duration of non-work-related sickness absence (NWRSA) across geographical areas and the degree to which this variation can be explained by individual and/or contextual factors. Methods: All first NWRSA episodes ending in 2007 and 2010 were analyzed. Individual (diagnosis, age, sex) and contextual factors (healthcare resources, socioeconomic factors) were analyzed to assess how much of the geographical variation was explained by these factors. Median N...

  13. Implications for risk assessment of host factors causing large pharmacokinetic variations

    Energy Technology Data Exchange (ETDEWEB)

    Vesell, E.S.

    1985-12-01

    Normal human subjects vary widely in their capacity to eliminate many drugs and environmental chemicals. These variations range in magnitude from fourfold to fortyfold depending on the drug and the population studied. Pharmacogenetics deals with only one of many host factors responsible for these large pharmacokinetic differences. Age, sex, diet and exposure to other drugs and chemicals, including oral contraceptives, ethanol and cigarette smoking, can alter the genetically determined rate at which a particular subject eliminates drugs and environmental chemicals. These elimination rates, therefore, are dynamic and change even in the same subject with time and condition. Regulatory legislation has only recently begun to recognize this very broad spectrum of human susceptibility and the existence of multiple special subgroups of particularly sensitive subjects. In setting standards for environmental chemicals, EPA and NIOSH have attempted to protect the most sensitive humans and should be encouraged to continue this policy. For some drugs and environmental chemicals, the commonly used safety factor of 100 may be too low; for these chemicals large, interindividual pharmacokinetic variations produced by pharmacogenetic and other host factors may make a safety factor of 400 or 500 more adequate.

  14. Assessment of Genetic Variation and Distribution Pattern of Thalictrum petaloideum Detected by RAPDs

    Institute of Scientific and Technical Information of China (English)

    XIELei; LILiang—Qian; ZHANGDa—Ming

    2004-01-01

    Random amplified polymerphic DNA(RAPD)method was applied to assessg enetic variation and population structure of Thahctrum petalotdeum L(Ranunoulaceae),Two hundred and forty-six individuals from 11 populations of the species were investigated by RAPD profiles Twenty selected RAPD primers generated 125 bands.in which 120 were polymorphic Ther esults revealed a high level of genetic variation(ercentage of polymorphIc bands(PPB was 96%.Nei’s gene diversity(りwas 03502 and shannon’s information index(I) was 0.5199 at the species level) The differentiation among the populations was high(Gst=0.3511)in this species.Result of analyzing of molecularvariance(AMOVA)showedthat38.88%of genetic variance was found among the populations Positive correlation withr r=01945(P=00002)was found between genetic distance and geographic distance amongpo pulations Two populations distributed in the drainage basin of YanELz River affined genedcally and formed one clada and the rest nine populations formed the other clade in both unweighted pair-group method using arithmetic average(UPGMA)trees made by two different method different methods. It was yen/clear that these two populations were very special, andmust be closely related in history, despite the fact that they now share quite weak link to the restpopulations through gene communication.

  15. Vitamin D status assessed by a validated HPLC method: within and between variation in subjects supplemented with vitamin D3

    DEFF Research Database (Denmark)

    Jakobsen, Jette; Bysted, Anette; Andersen, Rikke;

    2009-01-01

    Objective. The aim of this study was to develop and validate a high-pressure liquid chromatography (HPLC) method for assessing vitamin D status as 25-hydroxyvitamin D2 (S-25OHD2) and 25-hydroxyvitamin D3 (S-25OHD3) in serum. Material and methods. We assessed the within- and between...... estimated in each of the four human intervention studies did not differ significantly (p=0.55). Hence, the pooled standard deviation was 15.3 nmol 25OHD3/L. In the studies with 6-8 samplings during 7-20 months of supplementation, the within-subject variation was 3.9-7.2 nmol 25OHD3/L, while vitamin D status...

  16. Seasonal variation of levoglucosan in aerosols over the western North Pacific and its assessment as a biomass-burning tracer

    Science.gov (United States)

    Mochida, Michihiro; Kawamura, Kimitaka; Fu, Pingqing; Takemura, Toshihiko

    2010-09-01

    Levoglucosan is considered as a useful molecular tracer of biomass-burning aerosols in the atmosphere. To characterize the seasonal variation of its concentrations over the Pacific Ocean and to assess its usefulness as a tracer after long-range transport, we investigated long-term variations of levoglucosan over Chichi-jima in the western North Pacific, from 2001 to 2004. Organic carbon (OC), elemental carbon (EC) and D-glucose were analyzed for comparison. The seasonal variation of levoglucosan concentrations showed a maximum in the winter, which is consistent with the enhanced Asian outflow to the Pacific indicated by backward air-mass trajectories. The concentration levels of levoglucosan estimated from global aerosol model outputs in the winter are, on average, comparable to the observed levels, suggesting that a considerable fraction of levoglucosan did not decompose during long-range transport from the Asian continent by westerly/northwesterly winds. This result is supported by comparable ratios of levoglucosan to EC in Chichi-jima and the East Asian coastal region. Conversely, the measured concentrations of levoglucosan in the summer were significantly lower than the modeled one. This implies a degradation of levoglucosan in the air masses that stagnated over the Pacific, although uncertainties in the model estimate may also be partly responsible for this discrepancy. One possible degradation pathway is oxidation by OH radicals; the contribution of acid-catalyzed reactions needs further investigation.

  17. Assessment of Vegetation Variation on Primarily Creation Zones of the Dust Storms Around the Euphrates Using Remote Sensing Images

    Directory of Open Access Journals (Sweden)

    Jamil Amanollahi

    2012-06-01

    Full Text Available Recently, period frequency and effect domain of the dust storms that enter Iran from Iraq have increased. In this study, in addition to detecting the creation zones of the dust storms, the effect of vegetation cover variation on their creation was investigated using remote sensing. Moderate resolution image Spectroradiometer (MODIS and Landsat Thematic Mapper (TM5 have been utilized to identify the primarily creation zones of the dust storms and to assess the vegetation cover variation, respectively. Vegetation cover variation was studied using Normalized Differences Vegetation Index (NDVI obtained from band 3 and band 4 of the Landsate satellite. The results showed that the surrounding area of the Euphrates in Syria, the desert in the vicinity of this river in Iraq, including the deserts of Alanbar Province, and the north deserts of Saudi Arabia are the primarily creation zones of the dust storms entering west and south west of Iran. The results of NDVI showed that excluding the deserts in the border of Syria and Iraq, the area with very weak vegetation cover have increased between 2.44% and 20.65% from 1991 to 2009. In the meanwhile, the retention pound surface areas in the south deserts of Syria as well as the deserts in its border with Iraq have decreased 6320 and 4397 hectares, respectively. As it can be concluded from the findings, one of the main environmental parameters initiating these dust storms is the decrease in the vegetation cover in their primarily creation zones.

  18. MONTHLY VARIATION IN SPERM MOTILITY IN COMMON CARP ASSESSED USING COMPUTER-ASSISTED SPERM ANALYSIS (CASA)

    Science.gov (United States)

    Sperm motility variables from the milt of the common carp Cyprinus carpio were assessed using a computer-assisted sperm analysis (CASA) system across several months (March-August 1992) known to encompass the natural spawning period. Two-year-old pond-raised males obtained each mo...

  19. Considerations in the construction of an instrument to assess attitudes regarding critical illness gene variation research.

    Science.gov (United States)

    Freeman, Bradley D; Kennedy, Carie R; Bolcic-Jankovic, Dragana; Eastman, Alexander; Iverson, Ellen; Shehane, Erica; Celious, Aaron; Barillas, Jennifer; Clarridge, Brian

    2012-02-01

    Clinical studies conducted in intensive care units are associated with logistical and ethical challenges. Diseases investigated are precipitous and life-threatening, care is highly technological, and patients are often incapacitated and decision-making is provided by surrogates. These investigations increasingly involve collection of genetic data. The manner in which the exigencies of critical illness impact attitudes regarding genetic data collection is unstudied. Given interest in understanding stakeholder preferences as a foundation for the ethical conduct of research, filling this knowledge gap is timely. The conduct of opinion research in the critical care arena is novel. This brief report describes the development of parallel patient/surrogate decision-maker quantitative survey instruments for use in this environment. Future research employing this instrument or a variant of it with diverse populations promises to inform research practices in critical illness gene variation research. PMID:22378135

  20. Variation of indoor radon progeny concentration and its role in dose assessment

    International Nuclear Information System (INIS)

    Instantaneous measurements of equilibrium equivalent concentration of radon (EECRn) were taken over a period of 1 year in 2004 in a typical house at Amritsar city, located in the northwest part of India. A method based on absolute beta counting subsequent to grab aerosol sampling was used. During that year, EECRn varied between 1.56 Bq m-3 and 22.77 Bq m-3 with average value of 8.76 Bq m-3. EECRn decreased with the transition from winter to summer and vice versa, having a negative correlation with outdoor temperature. The use of mechanical ventilation, under normal living conditions during summer, caused an extra decrease in the concentrations. The variations with temperature and mechanical ventilation are discussed. Some major issues related to the uncertainties in dose calculations caused by the lack of knowledge of equilibrium factor and ignoring the effect of life style on the radon and its progeny concentrations are discussed

  1. InSAR Assessment of Ground Deformations in Shoreline Urban Areas Associated to Hydraulic Head Variations

    Science.gov (United States)

    Normand, J.; Heggy, E.

    2014-12-01

    Monitoring ground deformations in highly dense populated shoreline and lowlands areas such as Montreal is crucial for the sustainable development of urban infrastructures. Montreal already undergoes house foundations damages with a density of 8 repairs per square kilometer, especially over clay deposits such as in the Plateau neighborhood with a density of 89 repairs/km2. Using Radarsat-2 C-Band SAR interferometry, we observe a 3-5 mm ground LOS displacement variation temporally out-phased by three months relative to the 2 meter subartesian aquifer hydraulic head and river level variations, over a 60 km2 zone located in the central part of the Montreal Island in eastern Canada, from 2008 to 2010. Using ascending and descending SAR acquisition mode we extract the vertical component of the LOS velocities and observe secular displacements relative to a unconfined aquifer. These displacements are 2 mm/year subsidence on the minor topographic high, associated with evapotranspiration. We also observe ground water recharge and ~1 mm/year uplift downhill related to ground water discharge from deep regional aquifer enhanced with a faults system and shallow local aquifer arising from transmissivity. Displacements observed during this two year study are small but they are significant if integrated over the average lifetime of a house. We conclude that hydraulic head is related to the observed ground deformation in most of the areas of Montreal. Moreover, wetter climate conditions forecast for this area will definitely increase the aquifer dynamics; thus, more ground deformations are foreseen and have to be considered in future infrastructure design standards.

  2. Assessment of high (diurnal to low (seasonal frequency variations of isoprene emission rates using a neural network approach

    Directory of Open Access Journals (Sweden)

    C. Boissard

    2008-04-01

    Full Text Available Using a statistical approach based on artificial neural networks, an emission algorithm (ISO-LF accounting for high to low frequency variations was developed for isoprene emission rates. ISO-LF was optimised using a data base (ISO-DB specifically designed for this work, which consists of 1321 emission rates collected in the literature and 34 environmental variables, measured or assessed using National Climatic Data Center or National Centers for Environmental Predictions meteorological databases. ISO-DB covers a large variety of emitters (25 species and environmental conditions (10° S to 60° N. When only instantaneous environmental regressors (instantaneous air temperature T0 and photosynthetic photon flux density L0 were used, a maximum of 60% of the overall isoprene variability was assessed with the highest emissions being strongly underestimated. ISO-LF includes a total of 9 high (instantaneous to low (up to 3 weeks frequency regressors and accounts for up to 91% of the isoprene emission variability, whatever the emission range, species or climate investigated. ISO-LF was found to be mainly sensitive to air temperature cumulated over 3 weeks (T21 and to L0 and T0 variations. T21, T0 and L0 only accounts for 76% of the overall variability.

  3. Polycyclic aromatic hydrocarbons (PAHs) in water from three estuaries of China: Distribution, seasonal variations and ecological risk assessment.

    Science.gov (United States)

    Yan, Jinxia; Liu, Jingling; Shi, Xuan; You, Xiaoguang; Cao, Zhiguo

    2016-08-15

    The distribution, seasonal variations and ecological risk assessment of polycyclic aromatic hydrocarbons (PAHs) in water from three estuaries in Hai River Basin of China, which has been suffering from different anthropogenic pressures, were investigated. In three estuaries, the average concentration of ΣPAHs was the lowest in Luan River estuary, followed by Hai River estuary, and the highest in Zhangweixin River estuary. There were significant seasonal variations in ΣPAHs, the concentrations of ΣPAHs were higher in November than in May and August. The composition profiles of PAHs in different sites were significantly different, and illustrated seasonal variations. Generally, 2-ring (Nap) and 3-ring PAHs (Acp, Fl and Phe) were the most abundant components at most sampling sites in three estuaries. The PAHs in three estuaries were mainly originated from pyrogenic sources. A method based on toxic equivalency factors (TEFs) and risk quotient (RQ) was proposed to assess the ecological risk of ΣPAHs, with the ecological risk of individual PAHs being considered separately. The results showed that the ecological risks caused by ΣPAHs were high in Hai River estuary and Zhangweixin River estuary, and moderate in Luan River estuary. The mean values of ecological risk in August were lower than those in November. The contributions of individual PAHs to ecological risk were different in May, August and November. 3-ring and 4-ring PAHs accounted for much more ecological risk than 2-ring, 5-ring and 6-ring, although the contributions of 5-ring and 6-ring to ecological risk were higher than these to PAHs concentrations. PMID:27209122

  4. Feathers as a Tool to Assess Mercury Contamination in Gentoo Penguins: Variations at the Individual Level

    OpenAIRE

    Sara Pedro; Xavier, José C.; Sílvia Tavares; Trathan, Phil N.; Norman Ratcliffe; Paiva, Vitor H.; Renata Medeiros; Eduarda Pereira; Pardal, Miguel A.

    2015-01-01

    Feathers have been widely used to assess mercury contamination in birds as they reflect metal concentrations accumulated between successive moult periods: they are also easy to sample and have minimum impact on the study birds. Moult is considered the major pathway for mercury excretion in seabirds. Penguins are widely believed to undergo a complete, annual moult during which they do not feed. As penguins lose all their feathers, they are expected to have a low individual-variability in feath...

  5. An Assessment Of Time Variation In Solid And Hollow Floor Construction In Lagos State

    OpenAIRE

    Olumide, Afolarin Adenuga; Sotunbo, Gboyega

    2014-01-01

    The choice of construction method employed for constructing suspended slabs in buildings tend to impact significantly on the delivery time of building project. Thus, this study aims at assessing the impact of various construction methods on duration for constructing hollow and solid floor slabs in buildings in Lagos State, Nigeria. The research design for this study was a survey design approach and the populations of the study were professionals involved in construction projects; Archit...

  6. River Water Quality Assessment in Beed District of Maharashtra: Seasonal Parametric Variations.

    OpenAIRE

    R.A. Sayed; S. G. Gupta

    2010-01-01

    The water quality of rivers at Beed district was analyzed to assess their suitability for drinking and domestic. The sampling was done seasonally and the study period was divided into three seasons i.e. winter, summer and monsoon. The physico-chemical and bacteriological parameters were compared with standard values, recommended by Indian Council of Medical Research, the Bureau of Indian Standards and the World Health Organization. The water was found moderately hard and unfit for consumption...

  7. Spatial variation in lake benthic macroinvertebrate ecological assessment: a synthesis of European case studies

    DEFF Research Database (Denmark)

    Sandin, Leif Leonard; Solimini, Angelo G.

    2012-01-01

    This paper summarizes eight case studies that were analysed as part of the research theme ``lake benthic macroinvertebrates'' forming part of the EU-funded WISER project ``Water bodies in Europe: Integrative Systems to assess Ecological status and Recovery''. The relationships between lake benthi...... our aim is to provide useful information for designing monitoring programs and invertebrate based ecological classification tools with the ultimate aim to improve a sound management of European lake ecosystems....

  8. Parameter variation and scenario analysis in impact assessments of emerging energy technologies

    OpenAIRE

    Breunig, Hanna Marie

    2015-01-01

    There is a global need for energy technologies that reduce the adverse impacts of societal progress and that address today's challenges without creating tomorrow's problems. Life cycle impact assessment (LCIA) can support technology developers in achieving these prerequisites of sustainability by providing a systems perspective. However, modeling the early-stage scale up and impacts of technology systems may lead to unreliable or incomplete results due to a lack of representative technical, s...

  9. Correlations between soil microbial and physicochemical variations in a rice paddy: implications for assessing soil health

    Indian Academy of Sciences (India)

    Ryoichi Doi; Senaratne Leelananda Ranamukhaarachchi

    2009-12-01

    This study was conducted to test the hypothesis that spatial variations in soil microbial variables in a Thai rice paddy are accurately described by multivariate profiles of the soil bacterial communities. We found that community-level physiological profiles of soil bacterial communities could better describe the population density of Rhizoctonia solani in soil than the physicochemical profiles do. However, soil dehydrogenase levels were closely correlated with soil fertility ( < 0.05), and these were better described by the physicochemical profiles. Hence, the hypothesis was rejected, and we suspect that soil microbial variables react differently to the same physicochemical changes. The average population density of R. solani (35 colony-forming units/g dry soil) was relatively high in the soil we studied, and the soil fertility was found to be among the poorest in Thailand. The soil quality was comparable to the most degraded bare ground soil in an adjacent bioreserve in terms of Shannon diversity index based on the community-level physiological profile as well as values of soil fertility indices. Overall, the soil microbial and physicochemical indicators showed that the paddy soil needs to be supplemented with soil nutrients. Otherwise, R. solani may cause a significant reduction in rice production.

  10. Variation in heart rate influences the assessment of transient ischemic dilation in myocardial perfusion scintigraphy

    International Nuclear Information System (INIS)

    Transient arrhythmias can affect transient ischemic dilation (TID) ratios. This study was initiated to evaluate the frequency and effect of normal heart rate change on TID measures in routine clinical practice. Consecutive patients undergoing stress/rest sestamibi gated myocardial perfusion scintigraphy were studied (N = 407). Heart rate at the time of stress and rest imaging were recorded. TID ratios were analyzed in relation to absolute change in heart rate (stress minus rest) for subjects with normal perfusion and systolic function (Group 1, N = 169) and those with abnormalities in perfusion and/or function (Group 2, N = 238). In Group 1, mean TID ratio was inversely correlated with the change in heart rate (r = -0.47, P < 0.0001). For every increase of 10 BPM in heart rate change, the TID ratio decreased by approximately 0.06 (95% confidence interval 0.04–0.07). In Group 2, multiple linear regression demonstrated that the change in heart rate (beta = -0.25, P < 0.0001) and the summed difference score (beta = 0.36, P < 0.0001) were independent predictors of the TID ratio. Normal variation in heart rate between the stress and rest components of myocardial perfusion scans is common and can influence TID ratios in patients with normal and abnormal cardiac scans

  11. Temporal Variation of Chemical Persistence in a Swedish Lake Assessed by Benchmarking.

    Science.gov (United States)

    Zou, Hongyan; Radke, Michael; Kierkegaard, Amelie; McLachlan, Michael S

    2015-08-18

    Chemical benchmarking was used to investigate the temporal variation of the persistence of chemical contaminants in a Swedish lake. The chemicals studied included 12 pharmaceuticals, an artificial sweetener, and an X-ray contrast agent. Measurements were conducted in late spring, late autumn, and winter. The transformation half-life in the lake could be quantified for 7 of the chemicals. It ranged from several days to hundreds of days. For 5 of the chemicals (bezafibrate, climbazole, diclofenac, furosemide, and hydrochlorothiazide), the measured persistence was lower in late spring than in late autumn. This may have been caused by lower temperatures and/or less irradiation during late autumn. The seasonality in chemical persistence contributed to changes in chemical concentrations in the lake during the year. The impact of seasonality of persistence was compared with the impact of other important variables determining concentrations in the lake: chemical inputs and water flow/dilution. The strongest seasonal variability in chemical concentration in lake water was observed for hydrochlorothiazide (over a factor of 10), and this was attributable to the seasonality in its persistence. PMID:26171662

  12. Assessment of natural variation of iron and zinc isotope ratios during an iron intervention study in lactating women of Bangladesh

    International Nuclear Information System (INIS)

    A high proportion of people living in developing countries are deficient in Fe and Zn. Accurate markers for Fe status are available, but we lack effective markers to measure Zn status. Due to limitations of any single reliable method to determine zinc status, specific information on the prevalence of deficiency in particular settings is still lacking. State of art research indicates that the isotope ratios of Zn in human tissues are not in isotopic equilibrium. Differences in readings are expected to vary by up to 20 per mille in human tissues. In this study, we will examine natural variations in Fe and Zn isotope ratios in biological samples to provide new tools to assess Fe and Zn status of individuals. During the first 18 months a pilot study will be conducted with 16 lactating women in Bangladesh. Specific objectives of this study are (a) to assess the variation in the natural isotopic composition of iron and zinc isotopes in human biological samples before and after a three-month iron supplementation period and (b) to determine the natural variation of Fe and Zn isotopes in Bangladesh diet. There will be two study groups: One malnourished and one well-nourished group. Each group will consist of mothers in two subgroups: (1) iron supplementation, (2) no supplementation. Natural variation of Fe and Zn isotope will be determined in both well-nourished and malnourished women. Fe and Zn levels in blood, faeces, urine, hair and nails, will be determined. Hemoglobin, serum ferritin and serum transferrin receptor level will be measured to determine iron status. Subjects will be followed up at home weekly to ensure the continuity of supplementation. Blood, urine, stool, hair, and nail samples will be collected on in regular intervals from day 0 to 80 with special care to limit contamination, as Zn is especially prone to environmental contamination. Representative samples of Bangladeshi foods (meat, fish, vegetables, pulses, rice) will be collected from each of the two

  13. Limitations of early serum creatinine variations for the assessment of kidney injury in neonates and infants with cardiac surgery.

    Directory of Open Access Journals (Sweden)

    Mirela Bojan

    Full Text Available BACKGROUND: Changes in kidney function, as assessed by early and even small variations in serum creatinine (ΔsCr, affect survival in adults following cardiac surgery but such associations have not been reported in infants. This raises the question of the adequate assessment of kidney function by early ΔsCr in infants undergoing cardiac surgery. METHODOLOGY: The ability of ΔsCr within 2 days of surgery to assess the severity of kidney injury, accounted for by the risk of 30-day mortality, was explored retrospectively in 1019 consecutive neonates and infants. Patients aged ≤ 10 days were analyzed separately because of the physiological improvement in glomerular filtration early after birth. The Kml algorithm, an implementation of k-means for longitudinal data, was used to describe creatinine kinetics, and the receiver operating characteristic and the reclassification methodology to assess discrimination and the predictive ability of the risk of death. RESULTS: Three clusters of ΔsCr were identified: in 50% of all patients creatinine decreased, in 41.4% it increased slightly, and in 8.6% it rose abruptly. Mortality rates were not significantly different between the first and second clusters, 1.6% [0.0-4.1] vs 5.9% [1.9-10.9], respectively, in patients aged ≤ 10 days, and 1.6% [0.5-3.0] vs 3.8% [1.9-6.0] in older ones. Mortality rates were significantly higher when creatinine rose abruptly, 30.3% [15.1-46.2] in patients aged ≤ 10 days, and 15.1% [5.9-25.5] in older ones. However, only 41.3% of all patients who died had an abrupt increase in creatinine. ΔsCr improved prediction in survivors, but not in patients who died, and did not improve discrimination over a clinical mortality model. CONCLUSIONS: The present results suggest that a postoperative decrease in creatinine represents the normal course in neonates and infants with cardiac surgery, and that early creatinine variations lack sensitivity for the assessment of the severity of

  14. Benthic Foraminifera along a depth transect in western Bahrain: seasonal variations and environmental assessment

    Science.gov (United States)

    Muhammad, Arslan; Kaminski, Michael; Tawabini, Bassam; Ramadan, Khalid Al; Babalola, Lamidi; Frontalini, Fabrizio

    2015-04-01

    We surveyed living benthic foraminifera in a depth transect off western Bahrain (Arabian Gulf) with the aim of understanding the seasonal population dynamics and environmental parameters. In winter, the population was found to be highest due to the large number of rotaliids, followed by miliolids. In each season, the population was found to increase along the depth transect due to the higher number of juveniles. A strong correlation is observed between foraminiferal population and sediment grain size - the juveniles are most abundant on coarser-sandy substrate. The population decreases in the spring and is lowest in the summer. Finally, the living population recovered again in the autumn with increasing juveniles/adult ratios along the depth transect. Results of species consistency and relative abundance showed that Ammonia was consistent from the shallowest to the deepest station, whereas miliolids started appearing in the deeper stations. The average numbers of Elphidium and Peneroplis also increased along the depth transect. Another seasonal effect is that juveniles of Ammonia tepida are found during each season reflecting its reproduction throughout the year, whereas Brizalina pacifica was only found during spring and autumn. The study of environmental parameters reveals that the site is subjected to eutrophication i.e. nitrates and sulfates, however, pollution by heavy metals and hydrocarbons is not significant. An assessment of 63 heavy metals in sediment samples showed that none of the metals had concentrations higher than the internationally accepted norms, which is further confirmed by values of the Foraminiferal Deformities Index of less than 2%. Likewise, no hydrocarbons were detected in the water or sediment samples. Therefore, it is concluded that the site in Bahrain is not yet adversely affected by human development, and therefore can provide baseline information for future comparison and assessment of foraminiferal assemblages in contaminated zones

  15. Time-dependent Variation in Life Cycle Assessment of Microalgal Biorefinery Co-products

    Science.gov (United States)

    Montazeri, Mahdokht

    Microalgae can serve as a highly productive biological feedstock for fuels and chemicals. The lipid fraction of algal seeds has been the primary target of research for biofuel production. However, numerous assessments have found that valorization of co-products is essential to achieve economic and environmental goals. The relative proportion of co-products depends on the biomolecular composition of algae at the time of harvesting. In the present study the productivity of lipid, starch, and protein fractions were shown through growth experiments to vary widely with species, feeding regime, and harvesting time. Four algae species were cultivated under nitrogen-replete and -deplete conditions and analyzed at regular harvesting intervals. Dynamic growth results were then used for life cycle assessment using the U.S. Department of Energy's GREET model to determine optimal growth scenarios that minimize life cycle greenhouse gas (GHG) emissions, eutrophication, and cumulative energy demand (CED), while aiming for an energy return on investment (EROI) greater than unity. Per kg of biodiesel produced, C. sorokiniana in N-replete conditions harvested at 12 days was most favorable for GHG emissions and CED, despite having a lipid content of <20%. N. oculata under the same conditions had the lowest life cycle eutrophication impacts, driven by efficient nutrient cycling and valorization of microalgal protein and anaerobic digester residue co-products. The results indicate that growth cycle times that maximize a single fraction do not necessarily result in the most favorable environmental performance on a life cycle basis, underscoring the importance of designing biorefinery systems that simultaneously optimize for lipid and non-lipid fractions.

  16. Assessment of PD-1 gene variation in patients with multiple sclerosis

    Directory of Open Access Journals (Sweden)

    Shadmehri AA

    2010-05-01

    -RFLP."n"n Results: No significant association of the mutated alleles with the disease were detected. Because of the ethnic group genetic variation, our data is not like some of Asian population such as Korea and China."n"n Conclusions: Our data suggest that PD-1 polymorphisms are not act as genetic modifiers of the progression of MS, possibly these polymorphisms don't induce a partial defect in PD-1 mediated inhibition of T-cell activation.

  17. Assessment of Urban Infrastructure Impact on New York City Neighborhoods Thermal Variations

    Science.gov (United States)

    Nazari, R.; Ghandehari, M.; Karimi, M.; Vant-hull, B.; Khanbilvardi, R.

    2013-12-01

    New York City (NYC) is a highly urbanized city with most of the population living in tall buildings. Despite technological improvements and stricter regulations, cities still show increasing signs of environmental stress such as traffic congestion, noise and air quality degradation. Rethinking the current models of city planning could enable to limit these detrimental effects of urbanization. In addition, the built environment creates a new climatic regime which needs a better understanding. Building density, height and emission has a major impact on local temperature and other air quality indicators. Studies have shown that during extreme weather conditions and heat waves the mortality rate in urban areas increases. Cities are comprised of a wide variety of urban settings and various neighborhoods have different physical responses to meteorological events, so it is expected that the temperature and heat stress across a given city to fluctuate sharply. Therefore, this research has focused on neighborhood-scale field campaigns to downscale temperature and air quality predictions from city to neighborhood scale in NYC. In order to assess the temperature variability within the city at street level, during the hottest part of the day, this project used eight mobile units bearing temperature and relative humidity sensors, as well as ten weather stations mounted on light poles in various NYC neighborhoods. This study also looks at fine scale structures in the urban heat island of Manhattan at street level through an infrared camera with the spectral range of 7.5-13 μm in order to relate heat and emissions from building surfaces to land surface characteristics such as building density, vegetation coverage, proximity to water, and albedo. LandSat TM5 images were used (with 30 m resolution) for land surface classification. During the summer and early fall of 2011, 2012 and 2013 extensive field campaigns were performed, the results of which show some persistent patterns

  18. Comprehensive assessment of geographic variation in heat tolerance and hardening capacity in populations of Drosophila melanogaster from eastern Australia

    DEFF Research Database (Denmark)

    Sgro, Carla M.; Overgaard, Johannes; Kristensen, Torsten Nygård;

    2010-01-01

    (static) heat knockdown temperature increased towards temperate latitudes, probably reflecting a greater capacity of temperate flies to withstand sudden temperature increases during summer in temperate Australia. Larval viability showed a quadratic association with latitude under heat stress. Thus......We examined latitudinal variation in adult and larval heat tolerance in Drosophila melanogaster from eastern Australia. Adults were assessed using static and ramping assays. Basal and hardened static heat knockdown time showed significant linear clines; heat tolerance increased towards the tropics......, particularly for hardened flies, suggesting that tropical populations have a greater hardening response. A similar pattern was evident for ramping heat knockdown time at 0.06 degrees C min-1 increase. There was no cline for ramping heat knockdown temperature (CTmax) at 0.1 degrees C min-1 increase. Acute...

  19. A comprehensive assessment of geographic variation in heat tolerance and hardening capacity in populations of Drosophila melanogaster from eastern Australia

    DEFF Research Database (Denmark)

    Sgrò, C M; Overgaard, J; Kristensen, T N;

    2010-01-01

    knockdown temperature increased towards temperate latitudes, probably reflecting a greater capacity of temperate flies to withstand sudden temperature increases during summer in temperate Australia. Larval viability showed a quadratic association with latitude under heat stress. Thus, patterns of heat......We examined latitudinal variation in adult and larval heat tolerance in Drosophila melanogaster from eastern Australia. Adults were assessed using static and ramping assays. Basal and hardened static heat knockdown time showed significant linear clines; heat tolerance increased towards the tropics......, particularly for hardened flies, suggesting that tropical populations have a greater hardening response. A similar pattern was evident for ramping heat knockdown time at 0.06 °C min-1 increase. There was no cline for ramping heat knockdown temperature (CTmax) at 0.1 °C min-1 increase. Acute (static) heat...

  20. Assessment of genetic variation for the LINE-1 retrotransposon from next generation sequence data

    Directory of Open Access Journals (Sweden)

    Ramos Kenneth

    2010-10-01

    Full Text Available Abstract Background In humans, copies of the Long Interspersed Nuclear Element 1 (LINE-1 retrotransposon comprise 21% of the reference genome, and have been shown to modulate expression and produce novel splice isoforms of transcripts from genes that span or neighbor the LINE-1 insertion site. Results In this work, newly released pilot data from the 1000 Genomes Project is analyzed to detect previously unreported full length insertions of the retrotransposon LINE-1. By direct analysis of the sequence data, we have identified 22 previously unreported LINE-1 insertion sites within the sequence data reported for a mother/father/daughter trio. Conclusions It is demonstrated here that next generation sequencing data, as well as emerging high quality datasets from individual genome projects allow us to assess the amount of heterogeneity with respect to the LINE-1 retrotransposon amongst humans, and provide us with a wealth of testable hypotheses as to the impact that this diversity may have on the health of individuals and populations.

  1. Geographic variation in Northwest Atlantic fin whale (Balaenoptera physalus) song: implications for stock structure assessment.

    Science.gov (United States)

    Delarue, Julien; Todd, Sean K; Van Parijs, Sofie M; Di Iorio, Lucia

    2009-03-01

    Passive acoustic data are increasingly being used as a tool for helping to define marine mammal populations and stocks. Fin whale (Balaenoptera physalus) songs present a unique opportunity to determine interstock differences. Their highly stereotyped interpulse interval has been shown to vary between geographic areas and to remain stable over time in some areas. In this study the structure of songs recorded at two geographically close feeding aggregations in the Gulf of St. Lawrence (GSL) and Gulf of Maine (GoM) was compared. Recordings were made from September 2005 through February 2006 in the GSL and intermittently between January 2006 and September 2007 at two locations in the GoM. 6257 pulse intervals corresponding to 19 GSL and 29 GoM songs were measured to characterize songs from both areas. Classification trees showed that GSL songs differ significantly from those in the GoM. The results are consistent with those derived from other stock structure assessment methodologies, such as chemical signature and photoidentification analysis, suggesting that fin whales in these areas may form separate management stocks. Song structure analysis could therefore provide a useful and cost-efficient tool for defining conservation units over temporal and geographical scales relevant to management objectives in fin whales. PMID:19275334

  2. Assessing effects of variation in global climate data sets on spatial predictions from climate envelope models

    Science.gov (United States)

    Romanach, Stephanie; Watling, James I.; Fletcher, Robert J., Jr.; Speroterra, Carolina; Bucklin, David N.; Brandt, Laura A.; Pearlstine, Leonard G.; Escribano, Yesenia; Mazzotti, Frank J.

    2014-01-01

    Climate change poses new challenges for natural resource managers. Predictive modeling of species–environment relationships using climate envelope models can enhance our understanding of climate change effects on biodiversity, assist in assessment of invasion risk by exotic organisms, and inform life-history understanding of individual species. While increasing interest has focused on the role of uncertainty in future conditions on model predictions, models also may be sensitive to the initial conditions on which they are trained. Although climate envelope models are usually trained using data on contemporary climate, we lack systematic comparisons of model performance and predictions across alternative climate data sets available for model training. Here, we seek to fill that gap by comparing variability in predictions between two contemporary climate data sets to variability in spatial predictions among three alternative projections of future climate. Overall, correlations between monthly temperature and precipitation variables were very high for both contemporary and future data. Model performance varied across algorithms, but not between two alternative contemporary climate data sets. Spatial predictions varied more among alternative general-circulation models describing future climate conditions than between contemporary climate data sets. However, we did find that climate envelope models with low Cohen's kappa scores made more discrepant spatial predictions between climate data sets for the contemporary period than did models with high Cohen's kappa scores. We suggest conservation planners evaluate multiple performance metrics and be aware of the importance of differences in initial conditions for spatial predictions from climate envelope models.

  3. Assessing seasonal variations and age patterns in mortality during the first year of life in Tanzania.

    Science.gov (United States)

    Rumisha, S F; Smith, T; Abdulla, S; Masanja, H; Vounatsou, P

    2013-04-01

    Lack of birth and death registries in most of developing countries, particularly those in sub-Saharan Africa led to the establishment of Demographic Surveillance Systems (DSS) sites which monitor large population cohorts within defined geographical areas. DSS collects longitudinal data on migration, births, deaths and their causes via verbal autopsies. DSS data provide an opportunity to monitor many health indicators including mortality trends. Mortality rates in Sub-Sahara Africa show seasonal patterns due to high infant and child malaria-related mortality which is influenced by seasonal features present in environmental and climatic factors. However, it is unclear whether seasonal patterns differ by age in the first few months of life. This study provides an overview of approaches to assess, capture and detect seasonality peaks and patterns in mortality using the infant mortality data from the Rufiji DSS, Tanzania. Seasonality was best captured using Bayesian negative binomial models with time and cycle dependent seasonal parameters and autoregressive temporal error terms. Seasonal patterns are similar among different age groups during infancy and timing of their mortality peaks do not differ. Seasonality in mortality rates with two peaks per year is pronounced which corresponds to rainy seasons. Understanding of these trends is important for public health preparedness. PMID:23247213

  4. Radioactivity concentration variation with depth and assessment of workers' doses in selected mining sites

    Directory of Open Access Journals (Sweden)

    C.U. Nwankwo

    2015-04-01

    Full Text Available Mining workers are exposed to radiation in the process of extracting minerals from the earth crust. In this research, activity concentration of the radionuclides in samples collected at different depths in Komu (0–220 ft and Olode (0–30 ft mining sites, Oyo State, Nigeria and the associated workers' radiological risks were assessed. Gemstones from these sites are mined for local and international markets. The radionuclide contents of the samples were determined using Gamma spectroscopy technique. At Komu, 238U and 232Th concentrations, with few exceptions, increased with depth while that of 40K had no defined pattern. At Olode site, 238U and 232Th concentrations decreased with depth while that of 40K was almost constant. Internal hazard indices at Komu in some cases indicated an unacceptable level of risk to workers. Workers' doses would have been underestimated by between 12 and 55% if the activity concentrations of samples in the pit were not included in the calculation.

  5. Spatial and temporal variation in radiation exposure of amphibians - Implications for environmental risk assessment

    Energy Technology Data Exchange (ETDEWEB)

    Stark, K. [Stockholm University (Sweden)

    2014-07-01

    Although amphibians are threatened world-wide, many amphibian species are protected in national legislation. Thus, amphibians need special attention in many environmental risk assessments for releases of contaminants such as radionuclides. In fact, amphibians' ecology and physiology (including, for example, a complex life-cycle with both aquatic and terrestrial life stages, and a thin skin) makes them sensitive to radiation exposure. In current dose models for wildlife, homogenous distribution of radionuclides in soil is assumed. However, soils are heterogeneous environments and radionuclide contamination can be very unevenly distributed. As a consequence, bioaccumulation of radionuclides in biota may vary on a local scale. Specifically, organisms' spatial location and movement within habitats may affect both their external and internal exposure pattern to radionuclides. Therefore, measuring the spatial location of individual amphibians within ecosystems and understanding why they use these different locations is essential for predicting potential effects of released radionuclides on these populations. The aim of this study was to investigate amphibians' spatial distribution in a {sup 137}Cs contaminated wetland area and their body content of {sup 137}Cs at the beginning and end of the summer period. The study site was a wetland nature reserve called Bladmyra near Gaevle in the central-eastern part of Sweden. This area received fallout of {sup 137}Cs after the Chernobyl accident in 1986. This study measured the spatial distributions of two amphibian species (Rana arvalis and Bufo bufo) with Passive Integrated Transponder (PIT) tags in a mark-and-recapture study during 2012-2014. In addition, {sup 137}Cs body content in the two species was measured by whole body counting in spring and autumn of 2013. The results showed differences between years in how marked animals used the study area: More individuals stayed in a small area during 2012 than in 2013

  6. Spatial and temporal variation in radiation exposure of amphibians - Implications for environmental risk assessment

    International Nuclear Information System (INIS)

    Although amphibians are threatened world-wide, many amphibian species are protected in national legislation. Thus, amphibians need special attention in many environmental risk assessments for releases of contaminants such as radionuclides. In fact, amphibians' ecology and physiology (including, for example, a complex life-cycle with both aquatic and terrestrial life stages, and a thin skin) makes them sensitive to radiation exposure. In current dose models for wildlife, homogenous distribution of radionuclides in soil is assumed. However, soils are heterogeneous environments and radionuclide contamination can be very unevenly distributed. As a consequence, bioaccumulation of radionuclides in biota may vary on a local scale. Specifically, organisms' spatial location and movement within habitats may affect both their external and internal exposure pattern to radionuclides. Therefore, measuring the spatial location of individual amphibians within ecosystems and understanding why they use these different locations is essential for predicting potential effects of released radionuclides on these populations. The aim of this study was to investigate amphibians' spatial distribution in a 137Cs contaminated wetland area and their body content of 137Cs at the beginning and end of the summer period. The study site was a wetland nature reserve called Bladmyra near Gaevle in the central-eastern part of Sweden. This area received fallout of 137Cs after the Chernobyl accident in 1986. This study measured the spatial distributions of two amphibian species (Rana arvalis and Bufo bufo) with Passive Integrated Transponder (PIT) tags in a mark-and-recapture study during 2012-2014. In addition, 137Cs body content in the two species was measured by whole body counting in spring and autumn of 2013. The results showed differences between years in how marked animals used the study area: More individuals stayed in a small area during 2012 than in 2013, possibly due to differences in summer

  7. Mapping return levels of absolute NDVI variations for the assessment of drought risk in Ethiopia

    Science.gov (United States)

    Tonini, F.; Hochmair, H. H.; Jona Lasinio, G.

    2012-12-01

    The analysis and forecasting of extreme climatic events has become increasingly relevant to planning effective financial and food-related interventions in third-world countries. Natural disasters and climate change, both large and small scale, have a great impact on non-industrialized populations who rely exclusively on activities such as crop production, fishing, and similar livelihood activities. It is important to identify the extent of the areas prone to severe drought conditions in order to study the possible consequences of the drought on annual crop production. In this paper, we aim to identify such areas within the South Tigray zone, Ethiopia, using a transformation of the Normalized Difference Vegetation Index (NDVI) called Absolute Difference NDVI (ADVI). Negative NDVI shifts from the historical average can generally be linked to a reduction in the vigor of local vegetation. Drought is more likely to increase in areas where negative shifts occur more frequently and with high magnitude, making it possible to spot critical situations. We propose a new methodology for the assessment of drought risk in areas where crop production represents a primary source of livelihood for its inhabitants. We estimate ADVI return levels pixel per pixel by fitting extreme value models to independent monthly minima. The study is conducted using SPOT-Vegetation (VGT) ten-day composite (S10) images from April 1998 to March 2009. In all short-term and long-term predictions, we found that central and southern areas of the South Tigray zone are prone to a higher drought risk compared to other areas.; Temporal autocorrelation among monthly minima within the Alamata woreda. (a) ACF-Boxplot and (b) PACF-Boxplot. ; ADVI return level estimates. (a) 10-Month return levels. (b) 100-Month return levels. (c) 1000-Month return levels.

  8. Applying the PR and PP Methodology for a qualitative assessment of a misuse scenario in a notional Generation IV Example Sodium Fast Reactor. Assessing design variations

    International Nuclear Information System (INIS)

    qualitative assessment of the ESFR baseline design for a misuse scenario, and presents both the approach and the results of the assessment for the design variations DV0 and DV1. The results are then critically compared with those previously obtained for the baseline design and lessons learned are derived both on the system designs and on the methodology. (authors)

  9. Inter -and intraobserver variation of ultrasonographic cartilage thickness assessments in small and large joints in healthy children

    Directory of Open Access Journals (Sweden)

    Stenbøg Elisabeth

    2009-06-01

    Full Text Available Abstract Background There is an increasing interest among pediatric rheumatologist for using ultrasonography (US in the daily clinical examination of children with juvenile idiopathic arthritis (JIA. Loss of joint cartilage may be an early feature of destructive disease in JIA. However, US still needs validation before it can be used as a diagnostic bedside tool in a pediatric setting. This study aims to assess the inter- and intraobserver reliability of US measurements of cartilage thickness in the joints of healthy children. Methods 740 joints of 74 healthy Caucasian children (27 girls/47 boys, aged 11.3 (7.11 – 16 years were examined with bilateral US in 5 preselected joints to assess the interobserver variability. In 17 of these children (6 girls/11 boys, aged 10.1(7.11–11.1 years, 170 joints was examined in an intraobserver sub study, with a 2 week interval between the first and second examination. Results In this study we found a good inter- and intraobserver agreement expressed as a coefficient of variation (CV less than 10% in the knee (CV = 9.5%interobserver and 5.9%intraobservserI, 9.3%intraobserverII respectively for the two intraobserver measurements and fairly good for the MCP joints (CV = 11.9%interobserver, 12.9%intraobserverI and 11.9%intraobsevrerII. In the ankle and PIP joints the inter- and intraobserver agreement was within an acceptable limit (CV26%. We found no difference in cartilage thickness between the left and right extremity in the investigated joints. Conclusion We found a good inter -and intraobserver agreement when measuring cartilage thickness with US. The inter- and intraobserver variation seemed not to be related to joint size. These findings suggest that positioning of the joint and the transducer is of major importance for reproducible US measurements. We found no difference in joint cartilage thickness between the left and right extremity in any of the examined joint of the healthy children. This is an

  10. Assessing sources of error in comparative analyses of primate behavior: Intraspecific variation in group size and the social brain hypothesis.

    Science.gov (United States)

    Sandel, Aaron A; Miller, Jordan A; Mitani, John C; Nunn, Charles L; Patterson, Samantha K; Garamszegi, László Zsolt

    2016-05-01

    Phylogenetic comparative methods have become standard for investigating evolutionary hypotheses, including in studies of human evolution. While these methods account for the non-independence of trait data due to phylogeny, they often fail to consider intraspecific variation, which may lead to biased or erroneous results. We assessed the degree to which intraspecific variation impacts the results of comparative analyses by investigating the "social brain" hypothesis, which has provided a framework for explaining complex cognition and large brains in humans. This hypothesis suggests that group life imposes a cognitive challenge, with species living in larger social groups having comparably larger neocortex ratios than those living in smaller groups. Primates, however, vary considerably in group size within species, a fact that has been ignored in previous analyses. When within-species variation in group size is high, the common practice of using a mean value to represent the species may be inappropriate. We conducted regression and resampling analyses to ascertain whether the relationship between neocortex ratio and group size across primate species persists after controlling for within-species variation in group size. We found that in a sample of 23 primates, 70% of the variation in group size was due to between-species variation. Controlling for within-species variation in group size did not affect the results of phylogenetic analyses, which continued to show a positive relationship between neocortex ratio and group size. Analyses restricted to non-monogamous primates revealed considerable intraspecific variation in group size, but the positive association between neocortex ratio and group size remained even after controlling for within-species variation in group size. Our findings suggest that the relationship between neocortex size and group size in primates is robust. In addition, our methods and associated computer code provide a way to assess and account for

  11. Forced annular variations in the 20th century Intergovernmental Panel on Climate Change Fourth Assessment Report models

    Science.gov (United States)

    Miller, R. L.; Schmidt, G. A.; Shindell, D. T.

    2006-09-01

    We examine the annular mode within each hemisphere (defined here as the leading empirical orthogonal function and principal component of hemispheric sea level pressure) as simulated by the Intergovernmental Panel on Climate Change Fourth Assessment Report ensembles of coupled ocean-atmosphere models. The simulated annular patterns exhibit a high spatial correlation with the observed patterns during the late 20th century, though the mode represents too large a percentage of total temporal variability within each hemisphere. In response to increasing concentrations of greenhouse gases and tropospheric sulfate aerosols, the multimodel average exhibits a positive annular trend in both hemispheres, with decreasing sea level pressure (SLP) over the pole and a compensating increase in midlatitudes. In the Northern Hemisphere, the trend agrees in sign but is of smaller amplitude than that observed during recent decades. In the Southern Hemisphere, decreasing stratospheric ozone causes an additional reduction in Antarctic surface pressure during the latter half of the 20th century. While annular trends in the multimodel average are positive, individual model trends vary widely. Not all models predict a decrease in high-latitude SLP, although no model exhibits an increase. As a test of the models' annular sensitivity, the response to volcanic aerosols in the stratosphere is calculated during the winter following five major tropical eruptions. The observed response exhibits coupling between stratospheric anomalies and annular variations at the surface, similar to the coupling between these levels simulated elsewhere by models in response to increasing GHG concentration. The multimodel average is of the correct sign but significantly smaller in magnitude than the observed annular anomaly. This suggests that the models underestimate the coupling of stratospheric changes to annular variations at the surface and may not simulate the full response to increasing GHGs.

  12. Spectral mixture analysis to assess post-fire vegetation regeneration using Landsat Thematic Mapper imagery: Accounting for soil brightness variation

    Science.gov (United States)

    Veraverbeke, S.; Somers, B.; Gitas, I.; Katagis, T.; Polychronaki, A.; Goossens, R.

    2012-02-01

    Post-fire vegetation cover is a crucial parameter in rangeland management. This study aims to assess the post-fire vegetation recovery 3 years after the large 2007 Peloponnese (Greece) wildfires. Post-fire recovery landscapes typically are mixed vegetation-substrate environments which makes spectral mixture analysis (SMA) a very effective tool to derive fractional vegetation cover maps. Using a combination of field and simulation techniques this study aimed to account for the impact of background brightness variability on SMA model performance. The field data consisted out of a spectral library of in situ measured reflectance signals of vegetation and substrate and 78 line transect plots. In addition, a Landsat Thematic Mapper (TM) scene was employed in the study. A simple SMA, in which each constituting terrain feature is represented by its mean spectral signature, a multiple endmember SMA (MESMA) and a segmented SMA, which accounts for soil brightness variations by forcing the substrate endmember choice based on ancillary data (lithological map), were applied. In the study area two main spectrally different lithological units were present: relatively bright limestone and relatively dark flysch (sand-siltstone). Although the simple SMA model resulted in reasonable regression fits for the flysch and limestones subsets separately (coefficient of determination R2 of respectively 0.67 and 0.72 between field and TM data), the performance of the regression model on the pooled dataset was considerably weaker ( R2 = 0.65). Moreover, the regression lines significantly diverged among the different subsets leading to systematic over-or underestimations of the vegetative fraction depending on the substrate type. MESMA did not solve the endmember variability issue. The MESMA model did not manage to select the proper substrate spectrum on a reliable basis due to the lack of shape differences between the flysch and limestone spectra,. The segmented SMA model which accounts for

  13. On the use of the point-mass modeling technique for assessing ice-mass variations in alpine glacier systems

    Science.gov (United States)

    Reimond, Stefan; Baur, Oliver; Krauss, Sandro

    2016-04-01

    Most scientific studies dealing with gravity-based ice-mass balance estimations focus on the Earth's continental glacier systems, namely the Greenland and the Antarctica ice sheets. Alpine glacier regions such as the Alps, Himalaya or Patagonia, on the other hand, seem to be less considered. According to the most recent assessment report of the Intergovernmental Panel on Climate Change (IPCC), however, glacier shrinkage is one of the most dominant contributors to global sea level rise. In this context we investigate the capability of the point-mass modeling technique to assess ice-mass variations in small-scale alpine regions from space-borne gravimetric data. Two different approaches of this method can be distinguished: point-mass modeling with (i) predefined and fixed positions and (ii) with unknown locations of the surface mass changes. Approach (i) yields a linear functional model in which only the magnitudes of the point-masses are considered unknown. A highly non-linear optimization problem needs to be solved for approach (ii), since both the magnitudes and the coordinates of the point-masses are introduced as unknown parameters. In addition to that, owing to the effect of downward continuation, this problem is categorized as ill-posed and needs to be remedied by introducing regularization. The L-curve criterion or the generalized cross-validation method are typically used for selecting a suitable regularization factor. We conducted a series of close-loop simulation tests for various alpine glacier systems to compare the two approaches. In order to solve the global optimization problems in (i) and (ii), we make use of genetic algorithms.

  14. Seasonal variation effects on the formation of trihalomethane during chlorination of water from Yangtze River and associated cancer risk assessment

    Institute of Scientific and Technical Information of China (English)

    Shaogang Liu; Zhiliang Zhu; Chenfeng Fan; Yanling Qiu; Jianfu Zhao

    2011-01-01

    For the system of water samples collected from Yangtze River,the effects of seasonal variation and Fe(Ⅲ) concentrations on the formation and distribution of trihalomethanes (THMs) during chlorination have been investigated.The corresponding lifetime cancer risk of the formed THMs to human beings was estimated using the parameters and procedure issued by the US EPA.The results indicated that the average concentration of THMs (100.81 μg/L) in spring was significantly higher than that in other seasons,which was related to the higher bromide ion concentration resulted from the intrusion of tidal saltwater.The total cancer risk in spring reached 8.23 × 10-5 and 8.86 × 10-5 for males and females,respectively,which were about two times of those in summer under the experimental conditions.Furthermore,it was found that the presence of Fe(Ⅲ) resulted in the increased level of THMs and greater cancer risk from exposure to humans.Under weak basic conditions,about 10% of the increment of THMs from the water samples in spring was found in the presence of 0.5 mg/L Fe(Ⅲ) compared with the situation without Fe(Ⅲ).More attention should be given to the effect of the coexistence of Fe(Ⅲ) and bromide ions on the risk assessment of human intake of THMs from drinking water should be paid more attention,especially in the coastland and estuaries.

  15. Validation of a New Method for Stroke Volume Variation Assessment: a Comparaison with the PiCCO Technique

    CERN Document Server

    Laleg-Kirati, Taous-Meriem; Papelier, Yves; Cottin, François; Van De Louw, Andry

    2009-01-01

    This paper proposes a novel, simple and minimally invasive method for stroke volume variation assessment using arterial blood pressure measurements. The arterial blood pressure signal is reconstructed using a semi-classical signal analysis method allowing the computation of a parameter, called the first systolic invariant INVS1. We show that INVS1 is linearly related to stroke volume. To validate this approach, a statistical comparaison between INVS1 and stroke volume measured with the PiCCO technique was performed during a 15-mn recording in 21 mechanically ventilated patients in intensive care. In 94% of the whole recordings, a strong correlation was estimated by cross-correlation analysis (mean coefficient=0.9) and linear regression (mean coefficient=0.89). Once the linear relation had been verified, a Bland-Altman test showed the very good agreement between the two approaches and their interchangeability. For the remaining 6%, INVS1 and the PiCCO stroke volume were not correlated at all, and this discrepa...

  16. Dosimetric consequences of inter-fraction breathing-pattern variation on radiotherapy with personalized motion-assessed margins

    Science.gov (United States)

    Kavanagh, A.; McQuaid, D.; Evans, P.; Webb, S.; Guckenberger, M.

    2011-11-01

    The data from eight patients who had undergone stereotactic body radiotherapy were selected due to their 4D-CT planning scans showing that their tumours had respiratory induced motion trajectories of large amplitude (greater than 9 mm in cranio-caudal direction). Radiotherapy plans with personalized motion-assessed margins were generated for these eight patients. The margins were generated by inverse 4D planning on an eight-bin phase-sorted 4D-CT scan. The planning was done on an in-house software system with a non-rigid registration stage being completed using freely available software. The resultant plans were then recalculated on a 4D-CT scan taken later during the course of treatment. Simulated image-guided patient set-up was used to align the geometric centres of the tumour region and minimize any misalignment between the two reconstructions. In general, the variation in the patient breathing patterns was found to be very small. Consequently, the degradation of the mean dose to the tumour region was found to be around a few percent (<3%) and hence was not a large effect.

  17. Seasonal variations of belowground carbon transfer assessed by in situ 13CO2 pulse labelling of trees

    Directory of Open Access Journals (Sweden)

    P. Priault

    2011-02-01

    Full Text Available Soil CO2 efflux is the main source of CO2 from forest ecosystems and it is tightly coupled to the transfer of recent photosynthetic assimilates belowground and their metabolism in roots, mycorrhiza and rhizosphere microorganisms feeding on root-derived exudates. The objectives of our study were to assess patterns of belowground carbon allocation among tree species and along seasons. Pure 13CO2 pulse labelling of the entire crown of three different tree species (beech, oak and pine was carried out at distinct phenological stages. Excess 13C in soil CO2 efflux was tracked using tunable diode laser absorption spectrometry to determine time lags between the start of the labelling and the appearance of 13C in soil CO2 efflux and the amount of 13C allocated to soil CO2 efflux. Isotope composition (δ13C of CO2 respired by fine roots and soil microbes was measured at several occasions after labelling, together with δ13C of bulk root tissue and microbial carbon. Time lags ranged from 0.5 to 1.3 days in beech and oak and were longer in pine (1.6–2.7 days during the active growing season, more than 4 days during the resting season, and the transfer of C to the microbial biomass was as fast as to the fine roots. The amount of 13C allocated to soil CO2 efflux was estimated from a compartment model. Seasonal patterns of carbon allocation to soil CO2 efflux differed markedly between species, with pronounced seasonal variations in pine and beech. In beech, it may reflect competition with other sinks (aboveground growth in late spring and storage in late summer that were not observed in oak.

  18. Seasonal variations of belowground carbon transfer assessed by in situ 13CO2 pulse labelling of trees

    Directory of Open Access Journals (Sweden)

    L. Barthes

    2011-05-01

    Full Text Available Soil CO2 efflux is the main source of CO2 from forest ecosystems and it is tightly coupled to the transfer of recent photosynthetic assimilates belowground and their metabolism in roots, mycorrhiza and rhizosphere microorganisms feeding on root-derived exudates. The objective of our study was to assess patterns of belowground carbon allocation among tree species and along seasons. Pure 13CO2 pulse labelling of the entire crown of three different tree species (beech, oak and pine was carried out at distinct phenological stages. Excess 13C in soil CO2 efflux was tracked using tuneable diode laser absorption spectrometry to determine time lags between the start of the labelling and the appearance of 13C in soil CO2 efflux and the amount of 13C allocated to soil CO2 efflux. Isotope composition (δ13C of CO2 respired by fine roots and soil microbes was measured at several occasions after labelling, together with δ13C of bulk root tissue and microbial carbon. Time lags ranged from 0.5 to 1.3 days in beech and oak and were longer in pine (1.6–2.7 days during the active growing season, more than 4 days during the resting season, and the transfer of C to the microbial biomass was as fast as to the fine roots. The amount of 13C allocated to soil CO2 efflux was estimated from a compartment model. It varied between 1 and 21 % of the amount of 13CO2 taken up by the crown, depending on the species and the season. While rainfall exclusion that moderately decreased soil water content did not affect the pattern of carbon allocation to soil CO2 efflux in beech, seasonal patterns of carbon allocation belowground differed markedly between species, with pronounced seasonal variations in pine and beech. In beech, it may reflect competition with the strength of other sinks (aboveground growth in late spring and storage in late summer that were not observed in oak. We report a fast transfer of recent photosynthates to the mycorhizosphere and we conclude that the

  19. Comprehensive assessment of sequence variation within the copy number variable defensin cluster on 8p23 by target enriched in-depth 454 sequencing

    Directory of Open Access Journals (Sweden)

    Zhang Xinmin

    2011-05-01

    Full Text Available Abstract Background In highly copy number variable (CNV regions such as the human defensin gene locus, comprehensive assessment of sequence variations is challenging. PCR approaches are practically restricted to tiny fractions, and next-generation sequencing (NGS approaches of whole individual genomes e.g. by the 1000 Genomes Project is confined by an affordable sequence depth. Combining target enrichment with NGS may represent a feasible approach. Results As a proof of principle, we enriched a ~850 kb section comprising the CNV defensin gene cluster DEFB, the invariable DEFA part and 11 control regions from two genomes by sequence capture and sequenced it by 454 technology. 6,651 differences to the human reference genome were found. Comparison to HapMap genotypes revealed sensitivities and specificities in the range of 94% to 99% for the identification of variations. Using error probabilities for rigorous filtering revealed 2,886 unique single nucleotide variations (SNVs including 358 putative novel ones. DEFB CN determinations by haplotype ratios were in agreement with alternative methods. Conclusion Although currently labor extensive and having high costs, target enriched NGS provides a powerful tool for the comprehensive assessment of SNVs in highly polymorphic CNV regions of individual genomes. Furthermore, it reveals considerable amounts of putative novel variations and simultaneously allows CN estimation.

  20. Assessing genetic variation in natural populations of New World screwworm flies: Evidence from microsatellites and mitochondrial DNA

    International Nuclear Information System (INIS)

    , the patterns of haplotype distribution in Uruguay indicated that the populations were connected by gene flow and could be viewed as a unit. Most of the current projects that are based on nuclear markers use microsatellite DNA. Microsatellite sequences are the most revealing DNA markers available for inferring population-genetic structure and dynamics. Their introduction into population-genetic studies has greatly advanced our ability to assess population-genetic structure, to test parentage and relatedness, to assess genetic diversity, and to study recent population history. We have isolated 10 polymorphic microsatellite loci from an AC-enriched genomic library. Amplification of the reported loci in 30 C. hominivorax specimens from locations across South America revealed an average of 6.9 alleles per locus, with expected heterozygosities ranging from 0.3831 to 0.802. In addition to characterising the variability of the 10 loci in C. hominivorax, cross amplifications were done to test their applicability in four other calliphorid species. The results indicated that six of the loci may also be useful for genetic studies in the secondary screwworm, C. macellaria, and in other calliphorid species, such as Chrysomya bezziana (Old World screwworm fly) and Lucilia cuprina. Five microsatellite markers previously isolated were used to characterise C. hominivorax populations from Uruguay. All five loci investigated were polymorphic, revealing a high degree of polymorphism across the five sampling locations. The five populations exhibited remarkably similar allele distributions and shared the same predominant alleles at four of the examined loci. The global multilocus estimate of RST was 0.026 and of FST was 0.029. Both estimates, although low, were numerically very similar and significantly different from zero (P = 0.02630, for RST and P =0.001, for FST), suggesting that little differentiation exists among these populations. The analysed populations showed no isolation by

  1. Assessment of MODIS sun-sensor geometry variations effect on observed NDVI using MSG SEVIRI geostationary data

    DEFF Research Database (Denmark)

    Fensholt, R.; Sandholt, I.; Proud, Simon Richard;

    2010-01-01

    -sensor geometry variations will have a more visible impact on the Normalized Difference Vegetation Index (NDVI) from MODIS compared to earlier data sources, since noise related to atmosphere and sensor calibration is substantially reduced in the MODIS data stream. For this reason, the effect of varying MODIS...... cloud cover for three consecutive years (2004-2006). An analysis covering the entire range of NDVI revealed day-to-day variations in observed MODIS NDVI of 50-60% for medium dense vegetation (NDVI approximate to 0.5) caused by variations in MODIS view zenith angles (VZAs) between nadir and the high...... reflectances depends on the amount of vegetation present. MODIS VZA and RAA effects on NDVI were highest for medium dense vegetation (NDVI approximate to 0.5-0.6). The VZA and RAA effects were less for sparsely vegetated areas (NDVI approximate to 0.3-0.35) and the smallest effect on NDVI was found for dense...

  2. Magnetic resonance imaging of the calcaneus: preliminary assessment of trabecular bone-dependent regional variations in marrow relaxation time compared with dual X-ray absorptiometry

    Science.gov (United States)

    Guglielmi, G.; Selby, K.; Blunt, B. A.; Jergas, M.; Newitt, D. C.; Genant, H. K.; Majumdar, S.

    1996-01-01

    RATIONALE AND OBJECTIVES: Marrow transverse relaxation time (T2*) in magnetic resonance (MR) imaging may be related to the density and structure of the surrounding trabecular network. We investigated regional variations of T2* in the human calcaneus and compared the findings with bone mineral density (BMD), as measured by dual X-ray absorpiometry (DXA). Short- and long-term precisions were evaluated first to determine whether MR imaging would be useful for the clinical assessment of disease status and progression in osteoporosis. METHODS: Gradient-recalled echo MR images of the calcaneus were acquired at 1.5 T from six volunteers. Measurements of T2* were compared with BMD and (for one volunteer) conventional radiography. RESULTS: T2* values showed significant regional variation; they typically were shortest in the superior region of the calcaneus. There was a linear correlation between MR and DXA measurements (r = .66 for 1/T2* versus BMD). Differences in T2* attributable to variations in analysis region-of-interest placement were not significant for five of the six volunteers. Sagittal MR images had short- and long-term precision errors of 4.2% and 3.3%, respectively. For DXA, the precision was 1.3% (coefficient of variation). CONCLUSION: MR imaging may be useful for trabecular bone assessment in the calcaneus. However, given the large regional variations in bone density and structure, the choice of an ROI is likely to play a major role in the accuracy, precision, and overall clinical efficacy of T2* measurements.

  3. Assessment of variation in the alberta context tool: the contribution of unit level contextual factors and specialty in Canadian pediatric acute care settings

    Directory of Open Access Journals (Sweden)

    Cummings Greta G

    2011-10-01

    Full Text Available Abstract Background There are few validated measures of organizational context and none that we located are parsimonious and address modifiable characteristics of context. The Alberta Context Tool (ACT was developed to meet this need. The instrument assesses 8 dimensions of context, which comprise 10 concepts. The purpose of this paper is to report evidence to further the validity argument for ACT. The specific objectives of this paper are to: (1 examine the extent to which the 10 ACT concepts discriminate between patient care units and (2 identify variables that significantly contribute to between-unit variation for each of the 10 concepts. Methods 859 professional nurses (844 valid responses working in medical, surgical and critical care units of 8 Canadian pediatric hospitals completed the ACT. A random intercept, fixed effects hierarchical linear modeling (HLM strategy was used to quantify and explain variance in the 10 ACT concepts to establish the ACT's ability to discriminate between units. We ran 40 models (a series of 4 models for each of the 10 concepts in which we systematically assessed the unique contribution (i.e., error variance reduction of different variables to between-unit variation. First, we constructed a null model in which we quantified the variance overall, in each of the concepts. Then we controlled for the contribution of individual level variables (Model 1. In Model 2, we assessed the contribution of practice specialty (medical, surgical, critical care to variation since it was central to construction of the sampling frame for the study. Finally, we assessed the contribution of additional unit level variables (Model 3. Results The null model (unadjusted baseline HLM model established that there was significant variation between units in each of the 10 ACT concepts (i.e., discrimination between units. When we controlled for individual characteristics, significant variation in the 10 concepts remained. Assessment of the

  4. Assessment of interpatient heterogeneity in tumor radiosensitivity for nonsmall cell lung cancer using tumor-volume variation data

    Energy Technology Data Exchange (ETDEWEB)

    Chvetsov, Alexei V., E-mail: chvetsov2@gmail.com; Schwartz, Jeffrey L.; Mayr, Nina [Department of Radiation Oncology, University of Washington, 1959 NE Pacific Street, Seattle, Washington 98195-6043 (United States); Yartsev, Slav [London Regional Cancer Program, London Health Sciences Centre, 790 Commissioners Road East, London, Ontario 46A 4L6 (Canada)

    2014-06-15

    Purpose: In our previous work, the authors showed that a distribution of cell surviving fractionsS{sub 2} in a heterogeneous group of patients could be derived from tumor-volume variation curves during radiotherapy for head and neck cancer. In this research study, the authors show that this algorithm can be applied to other tumors, specifically in nonsmall cell lung cancer. This new application includes larger patient volumes and includes comparison of data sets obtained at independent institutions. Methods: Our analysis was based on two data sets of tumor-volume variation curves for heterogeneous groups of 17 patients treated for nonsmall cell lung cancer with conventional dose fractionation. The data sets were obtained previously at two independent institutions by using megavoltage computed tomography. Statistical distributions of cell surviving fractionsS{sub 2} and clearance half-lives of lethally damaged cells T{sub 1/2} have been reconstructed in each patient group by using a version of the two-level cell population model of tumor response and a simulated annealing algorithm. The reconstructed statistical distributions of the cell surviving fractions have been compared to the distributions measured using predictive assays in vitro. Results: Nonsmall cell lung cancer presents certain difficulties for modeling surviving fractions using tumor-volume variation curves because of relatively large fractional hypoxic volume, low gradient of tumor-volume response, and possible uncertainties due to breathing motion. Despite these difficulties, cell surviving fractionsS{sub 2} for nonsmall cell lung cancer derived from tumor-volume variation measured at different institutions have similar probability density functions (PDFs) with mean values of 0.30 and 0.43 and standard deviations of 0.13 and 0.18, respectively. The PDFs for cell surviving fractions S{sub 2} reconstructed from tumor volume variation agree with the PDF measured in vitro. Conclusions: The data obtained

  5. When Diagnosis Is Uncertain: Variation in Conclusions after Psychological Assessment of a Six-Year-Old Child

    Science.gov (United States)

    Russell, Ginny; Norwich, Brahm; Gwernan-Jones, Ruth

    2012-01-01

    A six-year-old child was independently assessed by three licensed educational (school) psychologists and one interdisciplinary team in the UK. All but one of these practitioners believed their assessment to be the first. The aim was to compare the practice of assessors and their conclusions especially in diagnostic categorisation. The methods of…

  6. Fungidice Risk Assessment for Aquatic Ecosystems: Importance of Interspecific Variation, Toxic Mode of Action, and Exposure Regime

    NARCIS (Netherlands)

    Maltby, L.; Brock, T.C.M.; Brink, van den P.J.

    2009-01-01

    The risk assessment of fungicides in Europe uses information from ecotoxicity studies performed on vertebrates, invertebrates, and primary producers, but not nontarget fungi. But which toxicity data should be used to assess risk and how important are modes of action and exposure regimes? A data set

  7. Assessment and reduction of comet assay variation in relation to DNA damage: studies from the European Comet Assay Validation Group

    DEFF Research Database (Denmark)

    Møller, Peter; Möller, Lennart; Godschalk, Roger W L;

    2010-01-01

    The alkaline single cell gel electrophoresis (comet) assay has become a widely used method for the detection of DNA damage and repair in cells and tissues. Still, it has been difficult to compare results from different investigators because of differences in assay conditions and because the data...... are reported in different units. The European Comet Assay Validation Group (ECVAG) was established for the purpose of validation of the comet assay with respect to measures of DNA damage formation and its repair. The results from this inter-laboratory validation trail showed a large variation in...... substantial reliability for the measurement of DNA damage by the comet assay but there is still a need for further validation to reduce both assay and inter-laboratory variation....

  8. Assessing inbreeding and loss of genetic variation in canids, domestic dog (Canis familiaris) and wolf (Canis lupus), using pedigree data

    OpenAIRE

    Jansson, Mija

    2014-01-01

    Genetic variation is necessary to maintain the ability of wild and domestic populations to genetically adapt to changed selective pressures. When relationships among individuals are known, conservation genetic management can be based on statistical pedigree analysis. Such approaches have traditionally focused on wild animal conservation breeding in captivity. In this thesis, I apply pedigree-based techniques to domestic and wild animal populations, focusing on two canids – the domestic dog an...

  9. Variations in microbial indicator densities in beach waters and health-related assessment of bathing water quality.

    OpenAIRE

    Cheung, W. H.; Chang, K C; Hung, R. P.

    1991-01-01

    Daily and hourly variations in microbial indicators densities in the beach-waters of Hong Kong have been described. The levels of Escherichia coli at a number of beaches was observed to be influenced by tide, and for staphylococci, by bather numbers. The tidal influence was most obvious during spring tides; and for the effect of bathers, during neap tides. Both organisms are present in high densities in external sources of faecal pollution of bathing beaches, with the average staphylococci to...

  10. Assessment of Morphometric and Genetic Variation in Three Freshwater Fish Species of the Genus Garra (Osteichthyes: Cyprinidae)

    OpenAIRE

    Arulraj DHINAKARAN; Nabeel Mannalamkunnath ALIKUNHI; Selvaraj CHINNATHAMBI; Ramaiya SORNAM; Kalaiselvam, Murugaiyan; Ramodoss RAJASEKARAN; Subramanian MANIVANNAN

    2011-01-01

    The present study evaluated the patterns of morphometric and genetic variation using RAPD-PCR techniques for the first time on three species of Garra, viz. G. mullya, G. kalakadensis and G. gotyla stenorhynchus, collected from various river basins of South-India. The results of morphological analysis revealed that G. mullya and G. kalakadensis hold many similar characters compared to the other congener, G. gotyla stenorhynchus. However, the G. gotyla stenorhynchus fish species exhibited disti...

  11. Effects of prolonged compression on the variations of haemoglobin oxygenation-assessment by spectral analysis of reflectance spectrophotometry signals

    International Nuclear Information System (INIS)

    The consequences of rhythmical flow motion for nutrition and the oxygen supply to tissue are largely unknown. In this study, the periodic variations of haemoglobin oxygenation in compressed and uncompressed skin were evaluated with a reflection spectrometer using an in vivo Sprague-Dawley rat model. Skin compression was induced over the trochanter area by a locally applied external pressure of 13.3 kPa (100 mmHg) via a specifically designed pneumatic indentor. A total of 19 rats were used in this study. The loading duration is 6 h per day for four consecutive days. Haemoglobin oxygenation variations were quantified using spectral analysis based on wavelets' transformation. The results found that in both compressed and uncompressed skin, periodic variations of the haemoglobin oxygenation were characterized by two frequencies in the range of 0.01-0.05 Hz and 0.15-0.4 Hz. These frequency ranges coincide with those of the frequency range of the endothelial-related metabolic and myogenic activities found in the flow motion respectively. Tissue compression following the above loading schedule induced a significant decrease in the spectral amplitudes of frequency interval 0.01-0.05 Hz during the pre-occlusion period on day 3 and day 4 as compared to that on day 1 (p 2 consumption rates of arteriolar walls. The modification of vessel wall oxygen consumption might substantially affect the available oxygen supply to the compressed tissue. This mechanism might be involved in the process leading to pressure ulcer formation

  12. Assessment of microscale spatio-temporal variation of air pollution at an urban hotspot in Madrid (Spain) through an extensive field campaign

    Science.gov (United States)

    Borge, Rafael; Narros, Adolfo; Artíñano, Begoña; Yagüe, Carlos; Gómez-Moreno, Francisco Javier; de la Paz, David; Román-Cascón, Carlos; Díaz, Elías; Maqueda, Gregorio; Sastre, Mariano; Quaassdorff, Christina; Dimitroulopoulou, Chrysanthi; Vardoulakis, Sotiris

    2016-09-01

    Poor urban air quality is one of the main environmental concerns worldwide due to its implications for population exposure and health-related issues. However, the development of effective abatement strategies in cities requires a consistent and holistic assessment of air pollution processes, taking into account all the relevant scales within a city. This contribution presents the methodology and main results of an intensive experimental campaign carried out in a complex pollution hotspot in Madrid (Spain) under the TECNAIRE-CM research project, which aimed at understanding the microscale spatio-temporal variation of ambient concentration levels in areas where high pollution values are recorded. A variety of instruments were deployed during a three-week field campaign to provide detailed information on meteorological and micrometeorological parameters and spatio-temporal variations of the most relevant pollutants (NO2 and PM) along with relevant information needed to simulate pedestrian fluxes. The results show the strong dependence of ambient concentrations on local emissions and meteorology that turns out in strong spatial and temporal variations, with gradients up to 2 μg m-3 m-1 for NO2 and 55 μg m-3 min-1 for PM10. Pedestrian exposure to these pollutants also presents strong variations temporally and spatially but it concentrates on pedestrian crossings and bus stops. The analysis of the results show that the high concentration levels found in urban hotspots depend on extremely complex dynamic processes that cannot be captured by routinely measurements made by air quality monitoring stations used for regulatory compliance assessment. The large influence from local traffic in the concentration fields highlights the need for a detailed description of specific variables that determine emissions and dispersion at microscale level. This also indicates that city-scale interventions may be complemented with local control measures and exposure management, to improve

  13. Assessment of variations in taxonomic diversity, forest structure, and aboveground biomass using remote sensing along an altitudinal gradient in tropical montane forest of Costa Rica

    Science.gov (United States)

    Robinson, C. M.; Saatchi, S. S.; Clark, D.; Fricker, G. A.; Wolf, J.; Gillespie, T. W.; Rovzar, C. M.; Andelman, S.

    2012-12-01

    This research sought to understand how alpha and beta diversity of plants vary and relate to the three-dimensional vegetation structure and aboveground biomass along environmental gradients in the tropical montane forests of Braulio Carrillo National Park in Costa Rica. There is growing evidence that ecosystem structure plays an important role in defining patterns of species diversity and along with abiotic factors (climate and edaphic) control the phenotypic and functional variations across landscapes. It is well documented that strong subdivisions at local and regional scales are found mainly on geologic or climate gradients. These general determinants of biodiversity are best demonstrated in regions with natural gradients such as tropical montane forests. Altitudinal gradients provide a landscape scale changes through variations in topography, climate, and edaphic conditions on which we tested several theoretical and biological hypotheses regarding drivers of biodiversity. The study was performed by using forest inventory and botanical data from nine 1-ha plots ranging from 100 m to 2800 m above sea level and remote sensing data from airborne lidar and radar sensors to quantify variations in forest structure. In this study we report on the effectiveness of relating patterns of tree taxonomic alpha diversity to three-dimensional structure of a tropical montane forest using lidar and radar observations of forest structure and biomass. We assessed alpha and beta diversity at the species, genus, and family levels utilizing datasets provided by the Terrestrial Ecology Assessment and Monitoring (TEAM) Network. Through the comparison to active remote sensing imagery, our results show that there is a strong relationship between forest 3D-structure, and alpha and beta diversity controlled by variations in abiotic factors along the altitudinal gradient. Using spatial analysis with the aid of remote sensing data, we find distinct patterns along the environmental gradients

  14. Delicious words - assessing the impact of short storytelling messages on consumer preferences for variations of a new processed meat product

    OpenAIRE

    Fenger, Morten; Aschemann-Witzel, Jessica; Hansen, Flemming; Klaus GRUNERT

    2014-01-01

    In this paper we present an experiment that tests the possible effect of adding the short type of "story" that is possible on a food label to variations of a product that is differentiated by its ingredients and way of production. We conduct an experiment where consumers have to choose from products consisting partly of this new type of product, partly of conventional products well known to consumers. We find that that while some consumers – especially those seeking stimulation and with a ten...

  15. Effects of prolonged compression on the variations of haemoglobin oxygenation-assessment by spectral analysis of reflectance spectrophotometry signals

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zengyong; Tam, Eric W C; Mak, Arthur F T; Lau, Roy Y C [Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Kowloon, Hong Kong (China)

    2006-11-07

    The consequences of rhythmical flow motion for nutrition and the oxygen supply to tissue are largely unknown. In this study, the periodic variations of haemoglobin oxygenation in compressed and uncompressed skin were evaluated with a reflection spectrometer using an in vivo Sprague-Dawley rat model. Skin compression was induced over the trochanter area by a locally applied external pressure of 13.3 kPa (100 mmHg) via a specifically designed pneumatic indentor. A total of 19 rats were used in this study. The loading duration is 6 h per day for four consecutive days. Haemoglobin oxygenation variations were quantified using spectral analysis based on wavelets' transformation. The results found that in both compressed and uncompressed skin, periodic variations of the haemoglobin oxygenation were characterized by two frequencies in the range of 0.01-0.05 Hz and 0.15-0.4 Hz. These frequency ranges coincide with those of the frequency range of the endothelial-related metabolic and myogenic activities found in the flow motion respectively. Tissue compression following the above loading schedule induced a significant decrease in the spectral amplitudes of frequency interval 0.01-0.05 Hz during the pre-occlusion period on day 3 and day 4 as compared to that on day 1 (p < 0.05). In contrast, at a frequency range of 0.15-0.4 Hz, prolonged compression caused a significant increase in spectral amplitude during the pre-occlusion period in the compressed tissue on day 3 (p = 0.041) and day 4 (p = 0.024) compared to that in the uncompressed tissue on day 1. These suggested that the variations of the haemoglobin oxygenation were closely related to the endothelial-related metabolic and myogenic activities. Increased amplitude in the frequency interval 0.15-0.4 Hz indicated an increased workload of the vascular smooth muscle and could be attributed to the increase of O{sub 2} consumption rates of arteriolar walls. The modification of vessel wall oxygen consumption might

  16. Assessment and management of interfractional variations in daily diagnostic-quality-CT guided prostate-bed irradiation after prostatectomy

    International Nuclear Information System (INIS)

    Purpose: To quantify interfractional anatomic variations and limitations of the current practice of image-guided radiation therapy (IGRT) for prostate-bed patients and to study dosimetric benefits of an online adaptive replanning scheme that addresses the interfractional variations. Methods: Contours for the targets and organs at risk (OARs) from daily diagnostic-quality CTs acquired with in-room CT (CTVision, Siemens) were generated by populating the planning contours using an autosegmentation tool based on deformable registration (ABAS, Elekta) with manual editing for ten prostate-bed patients treated with postoperative daily CT-guided IMRT. Dice similarity coefficient (DSC) obtained by maximizing the overlap of contours for a structure between the daily and plan contours was used to quantify the organ deformation between the plan and daily CTs. Three interfractional-variation-correction schemes, the current standard practice of IGRT repositioning, a previously developed online adaptive RT (ART), and the full reoptimization, were applied to these daily CTs and a number of dose-volume quantities for the targets and organs at risk were compared for their effectiveness to account for the interfractional variations. Results: Large interfractional organ deformations in prostate-bed irradiation were seen. The mean DSCs for CTV, rectum, and bladder were 86.6 ± 5.1% (range from 61% to 97%), 77.3% ± 7.4% (range from 55% to 90%), and 75.4% ± 11.2% (range from 46% to 96%), respectively. The fractional and cumulative dose-volume quantities for CTV and PTV: V100 (volume received at least 100% prescription dose), and rectum and bladder: V45Gy and V60Gy (volume received at least 45 or 60 Gy), were compared for the repositioning, adaptive, reoptimization, and original plans. The fractional and cumulative dosimetric results were nearly the same. The average cumulative CTV V100 were 88.0%, 98.4%, 99.2%, and 99.3% for the IGRT, ART, reoptimization, and original plans

  17. Assessing spatio-temporal variations of precipitation-use efficiency over Tibetan grasslands using MODIS and in-situ observations

    Science.gov (United States)

    Liu, Zhengjia; Huang, Mei

    2016-03-01

    Clarifying the spatial and temporal variations in precipitation-use efficiency (PUE) is helpful for advancing our knowledge of carbon and water cycles in Tibetan grassland ecosystems. Here we use an integrated remote sensing normalized difference vegetation index (NDVI) and in-situ above-ground net primary production (ANPP) measurements to establish an empirical exponential model to estimate spatial ANPP across the entire Tibetan Plateau. The spatial and temporal variations in PUE (the ratio of ANPP to mean annual precipitation (MAP)), as well as the relationships between PUE and other controls, were then investigated during the 2001-2012 study period. At a regional scale, PUE increased from west to east. PUE anomalies increased significantly (>0.1 g·m-2·mm-1/10 yr) in the southern areas of the Tibetan Plateau yet decreased (>0.02 g·m-2·mm-1/10 yr) in the northeastern areas. For alpine meadow, we obtained an obvious breaking point in trend of PUE against elevation gradients at 3600 m above the sea level, which showed a contrasting relationship. At the inter-annual scale, PUE anomalies were smaller in alpine steppe than in alpine meadow. The results show that PUE of Tibetan grasslands is generally high in dry years and low in wet years.

  18. Levels and variations in the quality of facility-based antenatal care in Kenya: evidence from the 2010 service provision assessment

    Science.gov (United States)

    Lee, Elizabeth; Madhavan, Supriya; Bauhoff, Sebastian

    2016-01-01

    Quality of care is emerging as an important concern for low- and middle-income countries working to expand and improve coverage. However, there is limited systematic, large-scale empirical guidance to inform policy design. Our study operationalized indicators for six dimensions of quality of care that are captured in currently available, standardized Service Provision Assessments. We implemented these measures to assess the levels and heterogeneity of antenatal care in Kenya. Using our indicator mix, we find that performance is low overall and that there is substantial variation across provinces, management authority and facility type. Overall, facilities performed highest in the dimensions of efficiency and acceptability/patient-centeredness, and lowest on effectiveness and accessibility. Public facilities generally performed worse or similarly to private or faith-based facilities. We illustrate how these data and methods can provide readily-available, low-cost decision support for policy. PMID:26879091

  19. Assessment of temporal and spatial variations in surface water quality using multivariate statistical techniques:A case study of Nenjiang River basin, China

    Institute of Scientific and Technical Information of China (English)

    郑力燕; 于宏兵; 王启山

    2015-01-01

    Assessment of temporal and spatial variations in surface water quality is important to evaluate the health of a watershed and make necessary management decisions to control current and future pollution of receiving water bodies. In this work, surface water quality data for 12 physical and chemical parameters collected from 10 sampling sites in the Nenjiang River basin during the years (2012−2013) were analyzed. The results show that river water quality has significant temporal and spatial variations. Hierarchical cluster analysis (HCA) grouped 12 months into three periods (LF, MF and HF) and classified 10 monitoring sites into three regions (LP, MP and HP) based on the similarity of water quality characteristics. The principle component analysis (PCA)/factor analysis (FA) was used to recognize the factors or origins responsible for temporal and spatial water quality variations. Temporal and spatial PCA/FA revealed that the Nenjiang River water chemistry was strongly affected by rock/water interaction, hydrologic processes and anthropogenic activities. This work demonstrates that the application of HCA and PCA/FA has achieved meaningful classification based on temporal and spatial criteria.

  20. Assessment of spatial variation in drinking water iodine and its implications for dietary intake: A new conceptual model for Denmark

    International Nuclear Information System (INIS)

    Iodine is essential for human health. Many countries have therefore introduced universal salt iodising (USI) programmes to ensure adequate intake for the populations. However, little attention has been paid to subnational differences in iodine intake from drinking water caused by naturally occurring spatial variations. To address this issue, we here present the results of a Danish nationwide study of spatial trends of iodine in drinking water and the relevance of these trends for human dietary iodine intake. The data consist of treated drinking water samples from 144 waterworks, representing approx. 45% of the groundwater abstraction for drinking water supply in Denmark. The samples were analysed for iodide, iodate, total iodine (TI) and other major and trace elements. The spatial patterns were investigated with Local Moran's I. TI ranges from < 0.2 to 126 μg L−1 (mean 14.4 μg L−1, median 11.9 μg L−1). Six speciation combinations were found. Half of the samples (n = 71) contain organic iodine; all species were detected in approx. 27% of all samples. The complex spatial variation is attributed both to the geology and the groundwater treatment. TI > 40 μg L−1 originates from postglacial marine and glacial meltwater sand and from Campanian–Maastrichtian chalk aquifers. The estimated drinking water contribution to human intake varies from 0% to > 100% of the WHO recommended daily iodine intake for adults and from 0% to approx. 50% for adolescents. The paper presents a new conceptual model based on the observed clustering of high or low drinking-water iodine concentrations, delimiting zones with potentially deficient, excessive or optimal iodine status. Our findings suggest that the present coarse-scale nationwide programme for monitoring the population's iodine status may not offer a sufficiently accurate picture. Local variations in drinking-water iodine should be mapped and incorporated into future adjustment of the monitoring and/or the USI

  1. Assessment of spatial variation in drinking water iodine and its implications for dietary intake: A new conceptual model for Denmark

    Energy Technology Data Exchange (ETDEWEB)

    Voutchkova, Denitza Dimitrova, E-mail: ddv@geo.au.dk [Department of Geoscience, Aarhus University, Høegh-Guldbergs Gade 2, DK-8000 Aarhus C (Denmark); Geological Survey of Denmark and Greenland (GEUS), Lyseng Allé 1, DK-8270 Højbjerg (Denmark); Geological Survey of Denmark and Greenland (GEUS), Øster Voldgade 10, DK-1350 Copenhagen K (Denmark); Ernstsen, Vibeke [Geological Survey of Denmark and Greenland (GEUS), Øster Voldgade 10, DK-1350 Copenhagen K (Denmark); Hansen, Birgitte; Sørensen, Brian Lyngby [Geological Survey of Denmark and Greenland (GEUS), Lyseng Allé 1, DK-8270 Højbjerg (Denmark); Zhang, Chaosheng [GIS Centre and School of Geography and Archaeology, National University of Ireland, Galway (Ireland); Kristiansen, Søren Munch [Department of Geoscience, Aarhus University, Høegh-Guldbergs Gade 2, DK-8000 Aarhus C (Denmark)

    2014-09-15

    Iodine is essential for human health. Many countries have therefore introduced universal salt iodising (USI) programmes to ensure adequate intake for the populations. However, little attention has been paid to subnational differences in iodine intake from drinking water caused by naturally occurring spatial variations. To address this issue, we here present the results of a Danish nationwide study of spatial trends of iodine in drinking water and the relevance of these trends for human dietary iodine intake. The data consist of treated drinking water samples from 144 waterworks, representing approx. 45% of the groundwater abstraction for drinking water supply in Denmark. The samples were analysed for iodide, iodate, total iodine (TI) and other major and trace elements. The spatial patterns were investigated with Local Moran's I. TI ranges from < 0.2 to 126 μg L{sup −1} (mean 14.4 μg L{sup −1}, median 11.9 μg L{sup −1}). Six speciation combinations were found. Half of the samples (n = 71) contain organic iodine; all species were detected in approx. 27% of all samples. The complex spatial variation is attributed both to the geology and the groundwater treatment. TI > 40 μg L{sup −1} originates from postglacial marine and glacial meltwater sand and from Campanian–Maastrichtian chalk aquifers. The estimated drinking water contribution to human intake varies from 0% to > 100% of the WHO recommended daily iodine intake for adults and from 0% to approx. 50% for adolescents. The paper presents a new conceptual model based on the observed clustering of high or low drinking-water iodine concentrations, delimiting zones with potentially deficient, excessive or optimal iodine status. Our findings suggest that the present coarse-scale nationwide programme for monitoring the population's iodine status may not offer a sufficiently accurate picture. Local variations in drinking-water iodine should be mapped and incorporated into future adjustment of the

  2. Initial Considerations When Applying an Instructional Sensitivity Framework: Partitioning the Variation between and within Classrooms for Two Mathematics Assessments

    Science.gov (United States)

    Ing, Marsha

    2016-01-01

    Drawing inferences about the extent to which student performance reflects instructional opportunities relies on the premise that the measure of student performance is reflective of instructional opportunities. An instructional sensitivity framework suggests that some assessments are more sensitive to detecting differences in instructional…

  3. Assessing the potential of SWVI (Soil Wetness Variation Index for hydrological risk monitoring by means of satellite microwave observations

    Directory of Open Access Journals (Sweden)

    T. Lacava

    2005-01-01

    Full Text Available In the last years satellite remote sensing applications in hydrology have considerably progressed. A new multi-temporal satellite data-analysis approach has been recently suggested in order to estimate space-time changes of geophysical parameters possibly related to the increase of environmental and hydro-geological hazards. Such an approach has been already used both for flooded area mapping (using AVHRR data and for soil wetness index estimation (using AMSU data. In this work, a preliminary sensitivity analysis of the proposed Soil Wetness Variation Index (SWVI is made in the case of low intensity meteorological events by the comparison with hydrological (precipitation data. This analysis, as a first step of a more complex work in progress, is targeted to a first evaluation of the reliability of the SWVI in describing soil response to precipitations of different duration and intensity.

  4. Deriving solar transient characteristics from single spacecraft STEREO/HI elongation variations: a theoretical assessment of the technique

    Directory of Open Access Journals (Sweden)

    A. O. Williams

    2009-12-01

    Full Text Available Recently, a technique has been developed whereby the radial velocity, Vr, and longitude direction, β, of propagation of an outward-moving solar transient, such as a Coronal Mass Ejection (CME, can be estimated from its track in a time-elongation map produced using Heliospheric Imager (HI observations from a single STEREO spacecraft. The method employed, which takes advantage of an artefact of projective geometry, is based on the evaluation of the best fit of the time-elongation profile of the transient, extracted from a time-elongation map, to a set of theoretical functions corresponding to known combinations of radial velocity and direction; here we present an initial theoretical assessment of the efficacy of this technique. As the method relies on the manual selection of points along the time-elongation profile, an assessment of the accuracy with which this is feasible, is initially made. The work then presented assesses theoretically this method of recovering the velocity and propagation direction of solar transients from their time-elongation profiles using a Monte-Carlo simulation approach. In particular, we assess the range of elongations over which it is necessary to make observations in order to accurately recover these parameters. Results of the Monte-Carlo simulations suggest that it is sufficient to track a solar transient out to around 40° elongation to provide accurate estimates of its associated radial velocity and direction; the accuracy to which these parameters can be estimated for a transient tracked over a particular elongation extent is, however, sensitive to its velocity and direction relative to the Sun-Spacecraft line. These initial results suggest that this technique based on single spacecraft STEREO/HI observations could prove extremely useful in terms of providing an early warning of a CME impact on the near-Earth environment.

  5. Large inter-individual variation in isoflavone plasma concentration limits use of isoflavone intake data for risk assessment

    OpenAIRE

    van der Velpen, V; Hollman, P.C.; Nielen, M; Schouten, E.G.; M. Mensink; van't Veer, P; Geelen, A

    2014-01-01

    Background/objectives: Isoflavones are present in soy foods and soy-based supplements. Despite low plasma isoflavone concentrations in the general Western population, concentrations in supplement users exceed those suggested to be beneficial for health in Asian populations, raising concerns for adverse effects. To aid risk assessment, quantification of the relation between isoflavone intake and plasma concentrations is essential. Subjects/methods: Plasma samples were collected from postmenopa...

  6. Assessment of Variation in Bacterial Composition among Microhabitats in a Mangrove Environment Using DGGE Fingerprints and Barcoded Pyrosequencing

    OpenAIRE

    Cleary, Daniel F R; Smalla, Kornelia; Leda C.S. Mendonça-Hagler; Gomes, Newton C. M.

    2012-01-01

    Here, we use DGGE fingerprinting and barcoded pyrosequencing data, at six cut-off levels (85–100%), of all bacteria, Alphaproteobacteria and Betaproteobacteria to assess composition in the rhizosphere of nursery plants and nursery-raised transplants, native plants and bulk sediment in a mangrove habitat. When comparing compositional data based on DGGE fingerprinting and barcoded pyrosequencing at different cut-off levels, all revealed highly significant differences in composition among microh...

  7. Effect of database profile variation on drug safety assessment: an analysis of spontaneous adverse event reports of Japanese cases

    Directory of Open Access Journals (Sweden)

    Nomura K

    2015-06-01

    Full Text Available Kaori Nomura,1 Kunihiko Takahashi,2 Yasushi Hinomura,3 Genta Kawaguchi,4 Yasuyuki Matsushita,5 Hiroko Marui,6 Tatsuhiko Anzai,7 Masayuki Hashiguchi,8 Mayumi Mochizuki8 1Division of Molecular Epidemiology, Jikei University School of Medicine, Tokyo, 2Department of Biostatistics, Nagoya University Graduate School of Medicine, Nagoya, 3Japan Pharmaceutical Information Center, 4Global Pharmacovigilance, Kissei Pharmaceutical Co Ltd, Tokyo, 5Medical Affairs Department, Daiichi Sankyo Co Ltd, 6Drug Safety Division, Chugai Pharmaceutical Co Ltd, 7Data Science Center, EPS Corporation, 8Faculty of Pharmacy, Keio University, Tokyo, Japan Background: The use of a statistical approach to analyze cumulative adverse event (AE reports has been encouraged by regulatory authorities. However, data variations affect statistical analyses (eg, signal detection. Further, differences in regulations, social issues, and health care systems can cause variations in AE data. The present study examined similarities and differences between two publicly available databases, ie, the Japanese Adverse Drug Event Report (JADER database and the US Food and Drug Administration Adverse Event Reporting System (FAERS, and how they affect signal detection.Methods: Two AE data sources from 2010 were examined, ie, JADER cases (JP and Japanese cases extracted from the FAERS (FAERS-JP. Three methods for signals of disproportionate reporting, ie, the reporting odds ratio, Bayesian confidence propagation neural network, and Gamma Poisson Shrinker (GPS, were used on drug-event combinations for three substances frequently recorded in both systems.Results: The two databases showed similar elements of AE reports, but no option was provided for a shareable case identifier. The average number of AEs per case was 1.6±1.3 (maximum 37 in the JP and 3.3±3.5 (maximum 62 in the FAERS-JP. Between 5% and 57% of all AEs were signaled by three quantitative methods for etanercept, infliximab, and

  8. Assessment of periodic sub-diurnal Earth rotation variations at tidal frequencies through transformation of VLBI normal equation systems

    Science.gov (United States)

    Artz, Thomas; Tesmer Née Böckmann, Sarah; Nothnagel, Axel

    2011-09-01

    We present an empirical model for periodic variations of diurnal and sub-diurnal Earth rotation parameters (ERPs) that was derived based on the transformation of normal equation (NEQ) systems of Very Long Baseline Interferometry (VLBI) observing sessions. NEQ systems that contain highly resolved polar motion and UT1-TAI with a temporal resolution of 15 min were generated and then transformed to the coefficients of the tidal ERP model to be solved for. To investigate the quality of this model, comparisons with empirical models from the Global Positioning System (GPS), another VLBI model and the model adopted by the conventions of the International Earth Rotation and Reference Systems Service (IERS) were performed. The absolute coefficients of these models agree almost completely within 7.5 μ as in polar motion and 0.5 μ s in UT1-TAI. Several bigger differences exist, which are discussed in this paper. To be able to compare the model estimates with results of the continuous VLBI campaigns, where signals with periods of 8 and 6 h were detected, terms in the ter- and quarter-diurnal band were included in the tidal ERP model. Unfortunately, almost no common features with the results of continuous VLBI campaigns or ERP predictions in these tidal bands can be seen.

  9. Assessment of sea surface temperature variations in the central North Atlantic using the alkenone unsaturation index (U 37k')

    Science.gov (United States)

    Villanueva, Joan; Grimalt, Joan O.; Cortijo, Elsa; Vidal, Laurence; Labeyrie, Laurent

    1998-07-01

    A high resolution record of U 37k' -derived SST estimations has been obtained in a core from the central North Atlantic Ocean (SU90/08, 43°30'N, 30°24'W) spanning a time period of 280 ky. The general trend of the U 37k' profile parallels closely the δ 180 signal and represent an independent confirmation that the SST variations in the glacial-interglacial time scales are correlated with the northern ice sheets evolution. In contrast to the CLIMAP (1984) conclusions based on the foraminiferal transfer function technique, the SST during the last interglacial period (LIP, isotopic stage 5.5) are 2-3°C warmer than during the Holocene. This result is in good agreement with many studies based in coastal and continental records that strongly suggest warmer climatic conditions over North America and Europe. Finally, the SST estimates during the last glacial maximum (LGM, 18 ky BP) where 4.5°C cooler than during the previous glacial period (PGP, stage 6). We argue that this difference is caused by a northward position of the polar front during the PGP in the Central North Atlantic.

  10. Seasonal variation of 222Rn in seawater samples from Ubatuba embayments, SP, Brazil, for the assessment of submarine groundwater discharge

    International Nuclear Information System (INIS)

    We describe here an application of excess 222Rn to estimate SGD in a series of small embayments of Ubatuba, Sao Paulo State, Brazil, covering latitudes between 23 deg 26'S and 23 deg 46'S and longitudes between 45 deg 02'W e 45 deg 11'W. Excess 222Rn inventories obtained in 24 vertical profiles established from March/03 to July/05 varied from 345 ±±24 to 18,700 ± 4,900 dpm/m2. The highest inventories of excess 222Rn were observed both in Flamengo and Fortaleza embayments, during summer campaigns (rainy season). The estimated total fluxes required to support inventories measured varied from 62 ± 4 to 3,385 +- 880 dpm/m2 d. Considering these results, the SGD advective rates necessary to balance the fluxes calculated in Ubatuba embayments ranged from 0.1 x 10-1 to 1.9 cm/d. Taking into account all SGD fluxes obtained, the percentual variability was 89% (seasonal variation in 3 years period, n = 24 measurements). Although, if we consider each year of study separately, the respective percentual variabilities estimated are 72% in 2003 (n = 10 measurements), 127% in 2004 (n = 6 measurements) and 97% in 2005 (n = 8 measurements). (author)

  11. Risk assessment and seasonal variations of dissolved trace elements and heavy metals in the Upper Han River, China

    International Nuclear Information System (INIS)

    Surface water samples were collected from 42 sampling sites throughout the upper Han River during the time period of 2005-2006. The concentrations of trace metals were determined using inductively coupled plasma-atomic emission spectrometry (ICP-AES) for the seasonal variability and preliminary risk assessment. The results demonstrated that concentrations of 11 heavy metals showed significant seasonality and most variables exhibited higher levels in the rainy season. Principal component analysis (PCA) and factor analysis (FA) revealed that variables governing water quality in one season may not be important in another season. Risk of metals on human health was then evaluated using Hazard Quotient (HQ) and carcinogenic risk, and indicated that As with HQ >1 and carcinogenic risk >10-4, was the most important pollutant leading to non-carcinogenic and carcinogenic concerns, in particular for children. The first five largest elements to chronic risks were As, Pb, V, Se and Sb, in the dry season, while they were As, V, Co, Pb and Sb in the rainy season. This assessment would help establish pollutant loading reduction goal and the total maximum daily loads, and consequently contribute to preserve public health in the Han River basin and develop water conservation strategy for the interbasin water transfer project.

  12. Assessment of Genetic Variation Within Indian Mustard(Brassica juncea) Germplasm Using Random Amplified Polymorphic DNA Markers

    Institute of Scientific and Technical Information of China (English)

    Muhammad Ayub Khan; Malik Ashiq Rabbani; Muharnmad Munir; Saifullah Khan Ajmal; Muhammad Azim Malik

    2008-01-01

    Genetic diversity among 45 Indian mustard (Brassica Juncea L.) genotypes comprising 37 germplasm collections, five advance breeding lines and three improved cultivars was investigated at the DNA level using the random amplified polymorphic DNA (RAPD) technique. Fifteen primers used generated a total of 92 RAPD fragments, of which 81 (88%) were polymorphic. Of these, 13 were unique to accession 'Pak85559'. Each primer produced four to nine amplified products with an average of 6.13 bands per primer. Based on pairwise comparisons of RAPD amplification products, Nei and Li's similarity coefficients were calculated to evaluate the relationships among the accessions. Pairwise similarity indices were higher among the oilseed accessions and cultivars showing narrow ranges of 0.77-0.99. An unweighted pair-group method with arithmetic averages cluster analysis based on these genetic similarities placed most of the collections and oilseed cultivars close to each other, showing a low level of polymorphism between the accessions used. However, the clusters formed by oilseed collections and cultivars were comparatively distinct from that of advanced breeding lines. Genetically, all of the accessions were classified into a few major groups and a number of individual accessions. Advanced breeding lines were relatively divergent from the rest of the accessions and formed independent clusters. Clustering of the accessions did not show any pattern of association between the RAPD markers and the collection sites. A low level of genetic variability of oilseed mustard was attributed to the selection for similar traits and horticultural uses. Perhaps close parentage of these accessions further contributed towards their little diversity. The study demonstrated that RAPD is a simple and fast technique to compare the genetic relationship and pattern of variation among the gene pool of this crop.

  13. Variation of phytoplankton assemblages of Kongsfjorden in early autumn 2012: a microscopic and pigment ratio-based assessment.

    Science.gov (United States)

    Bhaskar, Jane T; Tripathy, S C; Sabu, P; Laluraj, C M; Rajan, S

    2016-04-01

    Phytoplankton species distribution and composition were determined by using microscopy and pigment ratios in the Kongsfjorden during early autumn 2012. Variation in sea surface temperature (SST) was minimal and matched well with satellite-derived SST. Nutrients were generally limited. Surface phytoplankton abundance ranged from 0.21 × 10(3) to 10.28 × 10(3) cells L(-1). Phytoplankton abundance decreased with depth and did not show any significant correlation with chlorophyll a (chl a). Column-integrated phytoplankton cell counts (PCC) ranged from 94.3 × 10(6) cells m(-2) (Kf4) to 13.7 × 10(6) cells m(-2) (Kf5), while chl a was lowest at inner part of the fjord (6.3 mg m(-2)) and highest towards the mouth (24.83 mg m(-2)). Biomass from prymnesiophytes and raphidophytes dominated at surface and 10 m, respectively. The contribution of Bacillariophyceae to biomass was low. Generally, heterotrophic dinoflagellates were great in abundance (12.82 %) and ubiquitous in nature and were major contributors to biomass. Various chl pigments (chl b, chl c, phaeopigments (phaeo)) were measured to obtain pigment/chl a ratios to ascertain phytoplankton composition. Phaeo were observed only in inner fjord. Chl b:a ratios and microscopic observations indicated dominance of Chlorophyceae at greater depths than surface. Furthermore, microscopic observations confirmed dominance of chl c containing algae throughout the fjord. The study indicates that pigment ratios can be used as a tool for preliminary identification of major phytoplankton groups. However, under the presence of a large number of heterotrophic dinoflagellates such as Gymnodinium sp. and Gyrodinium sp., pigment signatures need to be supplemented by microscopic observations. PMID:26969156

  14. High Recharge Areas in the Choushui River Alluvial Fan (Taiwan Assessed from Recharge Potential Analysis and Average Storage Variation Indexes

    Directory of Open Access Journals (Sweden)

    Jui-Pin Tsai

    2015-03-01

    Full Text Available High recharge areas significantly influence the groundwater quality and quantity in regional groundwater systems. Many studies have applied recharge potential analysis (RPA to estimate groundwater recharge potential (GRP and have delineated high recharge areas based on the estimated GRP. However, most of these studies define the RPA parameters with supposition, and this represents a major source of uncertainty for applying RPA. To objectively define the RPA parameter values without supposition, this study proposes a systematic method based on the theory of parameter identification. A surrogate variable, namely the average storage variation (ASV index, is developed to calibrate the RPA parameters, because of the lack of direct GRP observations. The study results show that the correlations between the ASV indexes and computed GRP values improved from 0.67 before calibration to 0.85 after calibration, thus indicating that the calibrated RPA parameters represent the recharge characteristics of the study area well; these data also highlight how defining the RPA parameters with ASV indexes can help to improve the accuracy. The calibrated RPA parameters were used to estimate the GRP distribution of the study area, and the GRP values were graded into five levels. High and excellent level areas are defined as high recharge areas, which composed 7.92% of the study area. Overall, this study demonstrates that the developed approach can objectively define the RPA parameters and high recharge areas of the Choushui River alluvial fan, and the results should serve as valuable references for the Taiwanese government in their efforts to conserve the groundwater quality and quantity of the study area.

  15. Relative importance of modularity and other morphological attributes on different types of lithic point weapons: assessing functional variations.

    Directory of Open Access Journals (Sweden)

    Rolando González-José

    Full Text Available The specific using of different prehistoric weapons is mainly determined by its physical properties, which provide a relative advantage or disadvantage to perform a given, particular function. Since these physical properties are integrated to accomplish that function, examining design variables and their pattern of integration or modularity is of interest to estimate the past function of a point. Here we analyze a composite sample of lithic points from southern Patagonia likely formed by arrows, thrown spears and hand-held points to test if they can be viewed as a two-module system formed by the blade and the stem, and to evaluate the degree in which shape, size, asymmetry, blade: stem length ratio, and tip angle explain the observed variance and differentiation among points supposedly aimed to accomplish different functions. To do so we performed a geometric morphometric analysis on 118 lithic points, departing from 24 two-dimensional landmark and semi landmarks placed on the point's contour. Klingenberg's covariational modularity tests were used to evaluate different modularity hypotheses, and a composite PCA including shape, size, asymmetry, blade: stem length ratio, and tip angle was used to estimate the importance of each attribute to explaining variation patterns. Results show that the blade and the stem can be seen as "near decomposable units" in the points integrating the studied sample. However, this modular pattern changes after removing the effects of reduction. Indeed, a resharpened point tends to show a tip/rest of the point modular pattern. The composite PCA analyses evidenced three different patterns of morphometric attributes compatible with arrows, thrown spears, and hand-held tools. Interestingly, when analyzed independently, these groups show differences in their modular organization. Our results indicate that stone tools can be approached as flexible designs, characterized by a composite set of interacting morphometric

  16. Present and past microsatellite variation and assessment of genetic structure in Eurasian badger ( Meles meles ) in Denmark

    DEFF Research Database (Denmark)

    Pertoldi, C.; Loeschcke, V.; Randi, E.; Madsen, A.B.; Hansen, Michael Møller; Bijlsma, R.; Van De Zande, L.

    2005-01-01

    During the past 50 years the number of badgers (Meles meles) in Denmark has declined by c. 50%. To assess the genetic consequences of the demographic decline, six DNA-microsatellite loci were used to analyse 139 badger tissue-samples, which were collected in 1995-98 from three zones (1, 2 and 3) in...... Jutland (Denmark). Results from contemporary samples were compared to data obtained from DNA extracted from teeth belonging to 39 badgers collected from zones 1 and 2 in 1957-66. The microsatellites showed a low to moderate polymorphism, and the within area genetic diversity (H-E) was relatively low (0.......308 0.05). Despite the drastic recent decline, Danish badgers did not show apparent signs of genetic bottlenecks in both recent and historical samples. The use of molecular techniques which allowed us to work with small amounts of degraded DNA extracted from old teeth, allowed us to exclude the...

  17. Assessment of the Spatial and Temporal Variations of Water Quality for Agricultural Lands with Crop Rotation in China by Using a HYPE Model

    Science.gov (United States)

    Yin, Yunxing; Jiang, Sanyuan; Pers, Charlotta; Yang, Xiaoying; Liu, Qun; Yuan, Jin; Yao, Mingxing; He, Yi; Luo, Xingzhang; Zheng, Zheng

    2016-01-01

    Many water quality models have been successfully used worldwide to predict nutrient losses from anthropogenically impacted catchments, but hydrological and nutrient simulations with limited data are difficult considering the transfer of model parameters and complication of model calibration and validation. This study aims: (i) to assess the performance capabilities of a new and relatively more advantageous model, namely, Hydrological Predictions for the Environment (HYPE), that simulates stream flow and nutrient load in agricultural areas by using a multi-site and multi-objective parameter calibration method and (ii) to investigate the temporal and spatial variations of total nitrogen (TN) and total phosphorous (TP) concentrations and loads with crop rotation by using the model for the first time. A parameter estimation tool (PEST) was used to calibrate parameters. Results show that the parameters related to the effective soil porosity were highly sensitive to hydrological modeling. N balance was largely controlled by soil denitrification processes. P balance was influenced by the sedimentation rate and production/decay of P in rivers and lakes. The model reproduced the temporal and spatial variations of discharge and TN/TP relatively well in both calibration (2006–2008) and validation (2009–2010) periods. Among the obtained data, the lowest Nash-Suttclife efficiency of discharge, daily TN load, and daily TP load were 0.74, 0.51, and 0.54, respectively. The seasonal variations of daily TN concentrations in the entire simulation period were insufficient, indicated that crop rotation changed the timing and amount of N output. Monthly TN and TP simulation yields revealed that nutrient outputs were abundant in summer in terms of the corresponding discharge. The area-weighted TN and TP load annual yields in five years showed that nutrient loads were extremely high along Hong and Ru rivers, especially in agricultural lands. PMID:26999184

  18. Assessment of the Spatial and Temporal Variations of Water Quality for Agricultural Lands with Crop Rotation in China by Using a HYPE Model.

    Science.gov (United States)

    Yin, Yunxing; Jiang, Sanyuan; Pers, Charlotta; Yang, Xiaoying; Liu, Qun; Yuan, Jin; Yao, Mingxing; He, Yi; Luo, Xingzhang; Zheng, Zheng

    2016-01-01

    Many water quality models have been successfully used worldwide to predict nutrient losses from anthropogenically impacted catchments, but hydrological and nutrient simulations with limited data are difficult considering the transfer of model parameters and complication of model calibration and validation. This study aims: (i) to assess the performance capabilities of a new and relatively more advantageous model, namely, Hydrological Predictions for the Environment (HYPE), that simulates stream flow and nutrient load in agricultural areas by using a multi-site and multi-objective parameter calibration method and (ii) to investigate the temporal and spatial variations of total nitrogen (TN) and total phosphorous (TP) concentrations and loads with crop rotation by using the model for the first time. A parameter estimation tool (PEST) was used to calibrate parameters. Results show that the parameters related to the effective soil porosity were highly sensitive to hydrological modeling. N balance was largely controlled by soil denitrification processes. P balance was influenced by the sedimentation rate and production/decay of P in rivers and lakes. The model reproduced the temporal and spatial variations of discharge and TN/TP relatively well in both calibration (2006-2008) and validation (2009-2010) periods. Among the obtained data, the lowest Nash-Suttclife efficiency of discharge, daily TN load, and daily TP load were 0.74, 0.51, and 0.54, respectively. The seasonal variations of daily TN concentrations in the entire simulation period were insufficient, indicated that crop rotation changed the timing and amount of N output. Monthly TN and TP simulation yields revealed that nutrient outputs were abundant in summer in terms of the corresponding discharge. The area-weighted TN and TP load annual yields in five years showed that nutrient loads were extremely high along Hong and Ru rivers, especially in agricultural lands. PMID:26999184

  19. The Use of Focus-Variation Microscopy for the Assessment of Active Surfaces of a New Generation of Coated Abrasive Tools

    Directory of Open Access Journals (Sweden)

    Kapłonek Wojciech

    2016-04-01

    Full Text Available In this paper, the selected results of measurements and analysis of the active surfaces of a new generation of coated abrasive tools obtained by the use of focus-variation microscopy (FVM are presented and discussed. The origin of this technique, as well as its general metrological characteristics is briefly described. Additionally, information regarding the focus variation microscope used in the experiments - InfiniteFocus® IF G4 produced by Alicona Imaging, is also given. The measurements were carried out on microfinishing films (IMFF, abrasive portable belts with Cubitron™ II grains, and single-layer abrasive discs with Trizact™ grains. The obtained results were processed and analyzed employing TalyMap 4.0 software in the form of maps and profiles, surface microtopographies, Abbott- Firestone curves, and calculated values of selected areal parameters. This allowed us to describe the active surfaces of the coated abrasive tools, as well as to assess the possibility of applying the FVM technique in such kinds of measurements.

  20. Quantitative Assessment of Variational Surface Reconstruction from Sparse Point Clouds in Freehand 3D Ultrasound Imaging during Image-Guided Tumor Ablation

    Directory of Open Access Journals (Sweden)

    Shuangcheng Deng

    2016-04-01

    Full Text Available Surface reconstruction for freehand 3D ultrasound is used to provide 3D visualization of a VOI (volume of interest during image-guided tumor ablation surgery. This is a challenge because the recorded 2D B-scans are not only sparse but also non-parallel. To solve this issue, we established a framework to reconstruct the surface of freehand 3D ultrasound imaging in 2011. The key technique for surface reconstruction in that framework is based on variational interpolation presented by Greg Turk for shape transformation and is named Variational Surface Reconstruction (VSR. The main goal of this paper is to evaluate the quality of surface reconstructions, especially when the input data are extremely sparse point clouds from freehand 3D ultrasound imaging, using four methods: Ball Pivoting, Power Crust, Poisson, and VSR. Four experiments are conducted, and quantitative metrics, such as the Hausdorff distance, are introduced for quantitative assessment. The experiment results show that the performance of the proposed VSR method is the best of the four methods at reconstructing surface from sparse data. The VSR method can produce a close approximation to the original surface from as few as two contours, whereas the other three methods fail to do so. The experiment results also illustrate that the reproducibility of the VSR method is the best of the four methods.

  1. Genetic variation and phylogeography of Stauracanthus (Fabaceae, Genisteae) from the Iberian Peninsula and northern Morocco assessed by chloroplast microsatellite (cpSSR) markers.

    Science.gov (United States)

    Pardo, Cristina; Cubas, Paloma; Tahiri, Hikmat

    2008-01-01

    The tribe Genisteae includes genera of great ecological importance in Mediterranean countries because they are dominant elements of many plant communities. Genetic variation and diversification patterns in Stauracanthus (Genisteae) provide information relevant for the study of the processes of diversification in relation to the environmental history of the western Mediterranean. Nineteen populations of S. boivinii and S. genistoides were assessed by 11 chloroplast microsatellite markers, revealing 44 haplotypes. Both species had different haplotypes and contrasting patterns of karyological, morphological, and genetic variation. In the minimum spanning tree of the haplotypes, AMOVA analysis, and nested clade analysis, S. boivinii had high levels of differentiation and restricted gene flow among populations. Allopatric differentiation occurred between the Moroccan and Iberian populations of S. genistoides, although S. genistoides subsp. spectabilis and subsp. vicentinus had high levels of differentiation among populations (F(ST)), whereas S. genistoides subsp. genistoides had a low F(ST). Genetic patterns are discussed in relation to the Messinian salinity crisis (MSC): hard conditions drove plants to refuge habitats along the Atlantic coast and higher altitude areas in the Moroccan mountains (S. genistoides subsp. spectabilis and S. boivinii). After the MSC, S. boivinii underwent polyploidization and expansion, whereas S. genistoides expanded and continued diversifying into S. genistoides subspp. genistoides and vicentinus. PMID:21632320

  2. Assessing effects of seasonal variation on occupational exposure of newsagent kiosks to polycyclic aromatic hydrocarbons found in the urban atmosphere of Tehran Metropolitan

    Directory of Open Access Journals (Sweden)

    F Rezaei

    2015-08-01

    Full Text Available Background and Objectives: PAHs are main components of urban air pollution and are mutagenic for human being. Seasonal variations have effects on the amount of exposure to PAHs. The objectives of this research were to determine the amount of newsagent’s exposure to PAHs found in the urban atmosphere of Tehran City during warm and cold periods and comparing exposure levels in two periods. Materials and Methods: The assessment of personal exposure was performed based on NIOSH method 5515 and was analyzed by gas chromatography–mass spectrometry (GC/MS. Mann- Whitney test was used to determine the effects of seasonal variation on the amount of newsagent’s exposure to PAHs. Results: The mean levels of newsagent’s exposure to benzo[a]pyrene in the south area of Tehran City were 0.148±0.010 and 0.417±0.041 μg/m3 in summer and autumn seasons respectively. The amount was higher than the mean levels of newsagent’s exposure in other geographic areas of city. The levels of newsagent’s exposure to all PAHs (p<0.001 were significantly higher in autumn compared with summer. Conclusion: The levels of exposure to PAHs during autumn were 2 to 3 fold higher than the levels of exposure during summer. Newsagents in the south area of Tehran City were experiencing higher levels of exposures to PAHs.

  3. Assessment of the effect of the climate variations of coastal surface water and study of Sepia officinalis spawing

    Directory of Open Access Journals (Sweden)

    Carla Giansante

    2014-06-01

    Full Text Available The aim of this study was to establish whether climate change affected migratory behaviour of Sepia officinalis (Linnaeus, 1758, which is an important resource for small-scale fishermen of Abruzzo region (Italy. Starting at the beginning of March until the end of April, the cuttlefish in this area migrates from deep cold water towards warmer coastal waters, where they spawn. Small-scale fishing of cuttlefish is permitted in costal waters from March to September. During the study period, between March and September 2008, both cuttlefish traps and trammel nets were used in 5 sampling areas along the Abruzzo coast to test their relative efficiency in catching cuttlefish. Trapped specimens were counted, weighed and measured, their gender and sexual maturity were also determined. The data obtained from the sampling were correlated to surface water temperature to assess possible changes in migration behaviours. The obtained data show that during the first months of migration (March and April, a greater percentage of large males was caught, while females and smaller males predominated later in the year. The study also showed that surface water temperature did not reveal any significant shifts from the trend over the last 10 years. As for the efficiency of the fishing methods, traps were found to be more effective than trammel nets.

  4. Assessment of spatiotemporal variations in the fluvial wash-load component in the 21st century with regard to GCM climate change scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Mouri, Goro, E-mail: mouri@rainbow.iis.u-tokyo.ac.jp

    2015-11-15

    For stream water, in which a relationship exists between wash-load concentration and discharge, an estimate of fine-sediment delivery may be obtained from a traditional fluvial wash-load rating curve. Here, we demonstrate that the remaining wash-load material load can be estimated from a traditional empirical principle on a nationwide scale. The traditional technique was applied to stream water for the whole of Japan. Four typical GCMs were selected from the Coupled Model Intercomparison Project Phase 5 (CMIP5) ensemble to provide the driving fields for the following regional climate models to assess the wash-load component based on rating curves: the Model for Interdisciplinary Research on Climate (MIROC), the Meteorological Research Institute Atmospheric General Circulation Model (MRI-GCM), the Hadley Centre Global Environment Model (HadGEM) and the Geophysical Fluid Dynamics Laboratory (GFDL) climate model. The simulations consisted of an ensemble, including multiple physics configurations and different Representative Concentration Pathways (RCP2.6, RCP4.5 and RCP8.5), which was used to produce monthly datasets for the whole country of Japan. The impacts of future climate changes on fluvial wash load in Japanese stream water were based on the balance of changes in hydrological factors. The annual and seasonal variations of the fluvial wash load were assessed from the result of the ensemble analysis in consideration of the Greenhouse Gas (GHG) emission scenarios. The determined results for the amount of wash load increase range from approximately 20 to 110% in the 2040s, especially along part of the Pacific Ocean and the Sea of Japan regions. In the 2090s, the amount of wash load is projected to increase by more than 50% over the whole of Japan. The assessment indicates that seasonal variation is particularly important because the rainy and typhoon seasons, which include extreme events, are the dominant seasons. Because fluvial wash-load-component turbidity

  5. Assessment of spatiotemporal variations in the fluvial wash-load component in the 21st century with regard to GCM climate change scenarios

    International Nuclear Information System (INIS)

    For stream water, in which a relationship exists between wash-load concentration and discharge, an estimate of fine-sediment delivery may be obtained from a traditional fluvial wash-load rating curve. Here, we demonstrate that the remaining wash-load material load can be estimated from a traditional empirical principle on a nationwide scale. The traditional technique was applied to stream water for the whole of Japan. Four typical GCMs were selected from the Coupled Model Intercomparison Project Phase 5 (CMIP5) ensemble to provide the driving fields for the following regional climate models to assess the wash-load component based on rating curves: the Model for Interdisciplinary Research on Climate (MIROC), the Meteorological Research Institute Atmospheric General Circulation Model (MRI-GCM), the Hadley Centre Global Environment Model (HadGEM) and the Geophysical Fluid Dynamics Laboratory (GFDL) climate model. The simulations consisted of an ensemble, including multiple physics configurations and different Representative Concentration Pathways (RCP2.6, RCP4.5 and RCP8.5), which was used to produce monthly datasets for the whole country of Japan. The impacts of future climate changes on fluvial wash load in Japanese stream water were based on the balance of changes in hydrological factors. The annual and seasonal variations of the fluvial wash load were assessed from the result of the ensemble analysis in consideration of the Greenhouse Gas (GHG) emission scenarios. The determined results for the amount of wash load increase range from approximately 20 to 110% in the 2040s, especially along part of the Pacific Ocean and the Sea of Japan regions. In the 2090s, the amount of wash load is projected to increase by more than 50% over the whole of Japan. The assessment indicates that seasonal variation is particularly important because the rainy and typhoon seasons, which include extreme events, are the dominant seasons. Because fluvial wash-load-component turbidity

  6. Comparative Assessment of Genetic and Morphological Variation at an Extensive Hybrid Zone between Two Wild Cats in Southern Brazil

    Science.gov (United States)

    Trigo, Tatiane C.; Tirelli, Flávia P.; de Freitas, Thales R. O.; Eizirik, Eduardo

    2014-01-01

    Increased attention towards the Neotropical cats Leopardus guttulus and L. geoffroyi was prompted after genetic studies identified the occurrence of extensive hybridization between them at their geographic contact zone in southern Brazil. This is a region where two biomes intersect, each of which is associated with one of the hybridizing species (Atlantic Forest with L. guttulus and Pampas with L. geoffroyi). In this study, we conducted in-depth analyses of multiple molecular markers aiming to characterize the magnitude and spatial structure of this hybrid zone. We also performed a morphological assessment of these species, aiming to test their phenotypic differentiation at the contact zone, as well as the correlation between morphological features and the admixture status of the individuals. We found strong evidence for extensive and complex hybridization, with at least 40% of the individuals sampled in Rio Grande do Sul state (southernmost Brazil) identified as hybrids resulting from post-F1 generations. Despite such a high level of hybridization, samples collected in this state still comprised two recognizable clusters (genetically and morphologically). Genetically pure individuals were sampled mainly in regions farther from the contact zone, while hybrids concentrated in a central region (exactly at the interface between the two biomes). The morphological data set also revealed a strong spatial structure, which was correlated with the molecular results but displayed an even more marked separation between the clusters. Hybrids often did not present intermediate body sizes and could not be clearly distinguished morphologically from the parental forms. This observation suggests that some selective pressure may be acting on the hybrids, limiting their dispersal away from the hybrid zone and perhaps favoring genomic combinations that maintain adaptive phenotypic features of one or the other parental species. PMID:25250657

  7. Use of latent class models to accommodate inter-laboratory variation in assessing genetic polymorphisms associated with disease risk

    Directory of Open Access Journals (Sweden)

    Walter Stephen D

    2008-08-01

    Full Text Available Abstract Background Researchers wanting to study the association of genetic factors with disease may encounter variability in the laboratory methods used to establish genotypes or other traits. Such variability leads to uncertainty in determining the strength of a genotype as a risk factor. This problem is illustrated using data from a case-control study of cervical cancer in which some subjects were independently assessed by different laboratories for the presence of a genetic polymorphism. Inter-laboratory agreement was only moderate, which led to a very wide range of empirical odds ratios (ORs with the disease, depending on how disagreements were treated. This paper illustrates the use of latent class models (LCMs and to estimate OR while taking laboratory accuracy into account. Possible LCMs are characterised in terms of the number of laboratory measurements available, and if their error rates are assumed to be differential or non-differential by disease status and/or laboratory. Results The LCM results give maximum likelihood estimates of laboratory accuracy rates and the OR of the genetic variable and disease, and avoid the ambiguities of the empirical results. Having allowed for possible measurement error in the expure, the LCM estimates of exposure – disease associations are typically stronger than their empirical equivalents. Also the LCM estimates exploit all the available data, and hence have relatively low standard errors. Conclusion Our approach provides a way to evaluate the association of a polymorphism with disease, while taking laboratory measurement error into account. Ambiguities in the empirical data arising from disagreements between laboratories are avoided, and the estimated polymorphism-disease association is typically enhanced.

  8. Assessment of shoulder position variation and its impact on IMRT and VMAT doses for head and neck cancer

    International Nuclear Information System (INIS)

    For radiotherapy of the head and neck, 5-point mask immobilization is used to stabilize the shoulders. Still, the daily position of the shoulders during treatment may be different from the position in the treatment plan despite correct isocenter setup. The purpose of this study was to determine the interfractional displacement of the shoulders relative to isocenter over the course of treatment and the associated dosimetric effect of this displacement. The extent of shoulder displacements relative to isocenter was assessed for 10 patients in 5-point thermoplastic masks using image registration and daily CT-on-rails scans. Dosimetric effects on IMRT and VMAT plans were evaluated in Pinnacle based on simulation CTs modified to represent shoulder shifts between 3 and 15 mm in the superior-inferior, anterior-posterior, and right-left directions. The impact of clinically observed shoulder shifts on the low-neck dose distributions was examined. Shoulder motion was 2-5 mm in each direction on average but reached 20 mm. Superior shifts resulted in coverage loss, whereas inferior shifts increased the dose to the brachial plexus. These findings were generally consistent for both IMRT and VMAT plans. Over a course of observed shifts, the dose to 99% of the CTV decreased by up to 101 cGy, and the brachial plexus dose increased by up to 72 cGy. he position of the shoulder affects target coverage and critical structure dose, and may therefore be a concern during the setup of head and neck patients, particularly those with low neck primary disease

  9. Near Real-Time Assessment of Anatomic and Dosimetric Variations for Head and Neck Radiation Therapy via Graphics Processing Unit–based Dose Deformation Framework

    Energy Technology Data Exchange (ETDEWEB)

    Qi, X. Sharon, E-mail: xqi@mednet.ucla.edu [Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California (United States); Santhanam, Anand; Neylon, John; Min, Yugang; Armstrong, Tess; Sheng, Ke [Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California (United States); Staton, Robert J.; Pukala, Jason [Department of Radiation Oncology, UF Health Cancer Center - Orlando Health, Orlando, Florida (United States); Pham, Andrew; Low, Daniel A.; Lee, Steve P. [Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California (United States); Steinberg, Michael; Manon, Rafael [Department of Radiation Oncology, UF Health Cancer Center - Orlando Health, Orlando, Florida (United States); Chen, Allen M.; Kupelian, Patrick [Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California (United States)

    2015-06-01

    Purpose: The purpose of this study was to systematically monitor anatomic variations and their dosimetric consequences during intensity modulated radiation therapy (IMRT) for head and neck (H&N) cancer by using a graphics processing unit (GPU)-based deformable image registration (DIR) framework. Methods and Materials: Eleven IMRT H&N patients undergoing IMRT with daily megavoltage computed tomography (CT) and weekly kilovoltage CT (kVCT) scans were included in this analysis. Pretreatment kVCTs were automatically registered with their corresponding planning CTs through a GPU-based DIR framework. The deformation of each contoured structure in the H&N region was computed to account for nonrigid change in the patient setup. The Jacobian determinant of the planning target volumes and the surrounding critical structures were used to quantify anatomical volume changes. The actual delivered dose was calculated accounting for the organ deformation. The dose distribution uncertainties due to registration errors were estimated using a landmark-based gamma evaluation. Results: Dramatic interfractional anatomic changes were observed. During the treatment course of 6 to 7 weeks, the parotid gland volumes changed up to 34.7%, and the center-of-mass displacement of the 2 parotid glands varied in the range of 0.9 to 8.8 mm. For the primary treatment volume, the cumulative minimum and mean and equivalent uniform doses assessed by the weekly kVCTs were lower than the planned doses by up to 14.9% (P=.14), 2% (P=.39), and 7.3% (P=.05), respectively. The cumulative mean doses were significantly higher than the planned dose for the left parotid (P=.03) and right parotid glands (P=.006). The computation including DIR and dose accumulation was ultrafast (∼45 seconds) with registration accuracy at the subvoxel level. Conclusions: A systematic analysis of anatomic variations in the H&N region and their dosimetric consequences is critical in improving treatment efficacy. Nearly real

  10. Near Real-Time Assessment of Anatomic and Dosimetric Variations for Head and Neck Radiation Therapy via Graphics Processing Unit–based Dose Deformation Framework

    International Nuclear Information System (INIS)

    Purpose: The purpose of this study was to systematically monitor anatomic variations and their dosimetric consequences during intensity modulated radiation therapy (IMRT) for head and neck (H&N) cancer by using a graphics processing unit (GPU)-based deformable image registration (DIR) framework. Methods and Materials: Eleven IMRT H&N patients undergoing IMRT with daily megavoltage computed tomography (CT) and weekly kilovoltage CT (kVCT) scans were included in this analysis. Pretreatment kVCTs were automatically registered with their corresponding planning CTs through a GPU-based DIR framework. The deformation of each contoured structure in the H&N region was computed to account for nonrigid change in the patient setup. The Jacobian determinant of the planning target volumes and the surrounding critical structures were used to quantify anatomical volume changes. The actual delivered dose was calculated accounting for the organ deformation. The dose distribution uncertainties due to registration errors were estimated using a landmark-based gamma evaluation. Results: Dramatic interfractional anatomic changes were observed. During the treatment course of 6 to 7 weeks, the parotid gland volumes changed up to 34.7%, and the center-of-mass displacement of the 2 parotid glands varied in the range of 0.9 to 8.8 mm. For the primary treatment volume, the cumulative minimum and mean and equivalent uniform doses assessed by the weekly kVCTs were lower than the planned doses by up to 14.9% (P=.14), 2% (P=.39), and 7.3% (P=.05), respectively. The cumulative mean doses were significantly higher than the planned dose for the left parotid (P=.03) and right parotid glands (P=.006). The computation including DIR and dose accumulation was ultrafast (∼45 seconds) with registration accuracy at the subvoxel level. Conclusions: A systematic analysis of anatomic variations in the H&N region and their dosimetric consequences is critical in improving treatment efficacy. Nearly real

  11. An integrated, indicator framework for assessing large-scale variations and change in seasonal timing and phenology (Invited)

    Science.gov (United States)

    Betancourt, J. L.; Weltzin, J. F.

    2013-12-01

    As part of an effort to develop an Indicator System for the National Climate Assessment (NCA), the Seasonality and Phenology Indicators Technical Team (SPITT) proposed an integrated, continental-scale framework for understanding and tracking seasonal timing in physical and biological systems. The framework shares several metrics with the EPA's National Climate Change Indicators. The SPITT framework includes a comprehensive suite of national indicators to track conditions, anticipate vulnerabilities, and facilitate intervention or adaptation to the extent possible. Observed, modeled, and forecasted seasonal timing metrics can inform a wide spectrum of decisions on federal, state, and private lands in the U.S., and will be pivotal for international efforts to mitigation and adaptation. Humans use calendars both to understand the natural world and to plan their lives. Although the seasons are familiar concepts, we lack a comprehensive understanding of how variability arises in the timing of seasonal transitions in the atmosphere, and how variability and change translate and propagate through hydrological, ecological and human systems. For example, the contributions of greenhouse warming and natural variability to secular trends in seasonal timing are difficult to disentangle, including earlier spring transitions from winter (strong westerlies) to summer (weak easterlies) patterns of atmospheric circulation; shifts in annual phasing of daily temperature means and extremes; advanced timing of snow and ice melt and soil thaw at higher latitudes and elevations; and earlier start and longer duration of the growing and fire seasons. The SPITT framework aims to relate spatiotemporal variability in surface climate to (1) large-scale modes of natural climate variability and greenhouse gas-driven climatic change, and (2) spatiotemporal variability in hydrological, ecological and human responses and impacts. The hierarchical framework relies on ground and satellite observations

  12. A STUDY TO ASSESS THE PROPORTION AND ASSOCIATION OF APPENDICITIS WITH POSITIONAL VARIATION IN A SOUTH INDIAN RURAL TERTIARY CARE CENTER

    Directory of Open Access Journals (Sweden)

    Sandeep Kumar David

    2016-03-01

    Full Text Available CONTEXT The commonest position of appendix vermiformis according to the literature is retrocaecal. While during surgery there was found to have variation. Several studies done to assess the position of appendix vermiformis in patients with acute appendicitis has given a conflicting results. Depending on the position the symptom complex also changes, producing different problems and differential diagnosis. AIM This study assess the position of appendix vermiformis in patients with inflamed appendix in the patients undergoing surgery for acute appendicitis at Dr. SM CSI Medical College, Karakonam. DESIGN METHOD AND ANALYSIS The study is a retrospective study done over 2 years in 109 patients who underwent appendicectomy at Dr. SMCSI Medical College. The prevalence of appendicitis among different age groups, and the different position were studied. RESULTS Of the 109 patients 71 were females and 38 males. In the study population 21-40 years age group had the highest frequency of appendicitis. Subcaecal position was seen in 49.5 % of the patients followed by 28.4%. In both the sex group sub caecal position is the commonest position with 57.9% and 45.1% respectively in male and female patients. CONCLUSION Among the patients with acute appendicitis subcaecal position was the commonest position

  13. Variations of emission characterization of PAHs emitted from different utility boilers of coal-fired power plants and risk assessment related to atmospheric PAHs.

    Science.gov (United States)

    Wang, Ruwei; Liu, Guijian; Zhang, Jiamei

    2015-12-15

    Coal-fired power plants (CFPPs) represent important source of atmospheric PAHs, however, their emission characterization are still largely unknown. In this work, the concentration, distribution and gas-particle partitioning of PM10- and gas-phase PAHs in flue gas emitted from different coal-fired utility boilers were investigated. Moreover, concentration and distribution in airborne PAHs from different functional areas of power plants were studied. People's inhalatory and dermal exposures to airborne PAHs at these sites were estimated and their resultant lung cancer and skin cancer risks were assessed. Results indicated that the boiler capacity and operation conditions have significant effect on PAH concentrations in both PM10 and gas phases due to the variation of combustion efficiency, whereas they take neglected effect on PAH distributions. The wet flue gas desulphurization (WFGD) takes significant effect on the scavenging of PAH in both PM10 and gas phases, higher scavenging efficiency were found for less volatile PAHs. PAH partitioning is dominated by absorption into organic matter and accompanied by adsorption onto PM10 surface. In addition, different partitioning mechanism is observed for individual PAHs, which is assumed arising from their chemical affinity and vapor pressure. Risk assessment indicates that both inhalation and dermal contact greatly contribute to the cancer risk for CFPP workers and nearby residents. People working in workshop are exposed to greater inhalation and dermal exposure risk than people living in nearby vicinity and working office. PMID:26298851

  14. Assessment of the variation of natural radioactivity in sands of Camburi beach, Vitoria, Epirito Santo, Brazil with climatological and geological factors of the region

    International Nuclear Information System (INIS)

    The main contribution to the external exposure to humans comes from gamma emitting radionuclides in soils, especially the 40K and 238U and 232Th series. In this work, the activity concentrations of 226Ra (238U series), 232Th and 40K in surface sand monthly collected at 11 sites along the Camburi beach during the year 2011, selected to cover the entire length of the beach, were determined. The samples were hermetically sealed and measured by high resolution gamma spectrometry, after a resting time of approximately 30 days, in order to attain the radioactive equilibrium in the 238U and 232Th series. The activity concentration of 226Ra was determined by the weighted average concentrations of 214Pb and 214Bi, the activity concentration of 232Th by the weighted average concentrations of 212Pb, 212Bi and 228Ac. The activity of 40K was determined by its single transition of 1460,8 keV. For all samples the concentrations were corrected by self attenuation factors. From these concentrations, radiological indices like radium equivalent activity (Raeq), activity concentration index (Iγ), external exposure risk index (Hext), internal exposure risk index (Hint), absorbed gamma dose rate in air (D) in nGy.h-1 and annual effective dose (E) in mSv.y-1 were evaluated. In the studied area it was realized an assessment of the correlation of the activity concentrations of 226Ra, 232Th and 40K with the geological, geographical, climatological (rainfall and temperature) and oceanographic (tidal height variation) factors. Due to the strong presence of monazite, the concentration of 232Th is higher than the concentration of 226Ra and 40K. The activity concentrations found ranged from 4 Bq.kg-1 to 1380 Bq.kg-1 for 226Ra, from 9 Bq.kg-1 to 7453 Bq.kg-1 for 232Th and 6 Bq.kg-1 to 504 Bq.kg-1 for 40K. The variation of Raeq from 20 Bq.kg-1 to 12077 Bq.kg-1, of Iγ from 0,07 to 42,08, of Hext from 0,05 to 32,61, of Hint from 0,06 to 36,34 and of absorbed gamma dose rate in air from 0,05 to 32

  15. Comparison of apparent diffusion coefficient and T2 relaxation time variation patterns in assessment of age and disc level related intervertebral disc changes.

    Directory of Open Access Journals (Sweden)

    Nan Wu

    Full Text Available PURPOSE: To compare the variation patterns of ADC and T2 values in different age and intervertebral disc (IVD levels, thus to identify their sensitivities in assessing age and disc level related IVDs changes. MATERIALS AND METHODS: The T2 and ADC values were recorded from 345 IVDs of 69 volunteers. Kendall's correlation analysis was used to identify the relationship between age and T2/ADC mean values respectively. The one-way analysis of variance (ANOVA with post hoc analysis was then applied to test the differences of T2 and ADC values among different IVD levels and age groups, followed by linear regression analysis between age (45 years and T2/ADC mean values. This study was approved by the Ethics Committee of the Chinese Academy of Medical Sciences and the Peking Union Medical College Hospital. RESULTS: Significant negative correlation was observed between age and T2/ADC mean values. The T2 and ADC values showed significant differences among IVD levels and among age groups except for T2 values in age group 1 (25-34 years and group 2 (35-44 years, and for ADC values at L1-2 level. Both T2 and ADC values showed significant differences between young (age45 years at each IVD level. A linear relationship was observed between age and T2/ADC mean values in the elderly group as well as in the young group for the ADC mean values, while no such tendency was identified in the young group for the T2 mean values. CONCLUSIONS: ADC values may be a more sensitive parameter than T2 in assessing age and disc level related intervertebral disc changes.

  16. Evaluation of the seasonal variation on the geochemical parameters and quality assessment of the groundwater in the proximity of River Cooum, Chennai, India.

    Science.gov (United States)

    Giridharan, L; Venugopal, T; Jayaprakash, M

    2008-08-01

    The seasonal variations of the chemical budget of ions were determined from the hydrochemical investigation of the groundwater. Though the effect of monsoon does not change the order of abundance of cations, but it does change the concentration of various ions and it is found that there was a considerable change in the case of all major ions. The unique characteristic of the ground water is the linear relationship among the principal ions. Hydrochemical characteristics of ions in the groundwater were studied using 1:1 equiline diagrams. The nature of the water samples were determined using the piper diagram. The correlation studies and R-mode factor analysis were carried out on the various groundwater parameters. The study of factor scores reveals the extent of influence of each factors on the overall water chemistry at each sampling stations. The trace metal concentration in the water was determined. The quality of the groundwater in the study area has been assessed using Percent sodium, SAR and Wilcox diagrams. The groundwater results of the premonsoon shows the dominance of excessive evaporation, silicate weathering and anthropogenic activities whereas in postmonsoon, dilution predominates over that of other factors. PMID:17891526

  17. Assessing levels and seasonal variations of current-use pesticides (CUPs) in the Tuscan atmosphere, Italy, using polyurethane foam disks (PUF) passive air samplers

    International Nuclear Information System (INIS)

    Polyurethane foam disks (PUF) passive air samplers (PAS) were deployed over 4 sampling periods of 3–5-months (≥ 1 year) at ten urban and rural locations throughout the Tuscany Region. The purpose was to assess the occurrence and seasonal variations of ten current-use pesticides (CUPs). PUF disk extracts were analyzed using GC–MS. The organophosphates insecticides; chlorpyrifos (3–580 pg m−3) and chlorpyrifos-methyl (below detection limit – to 570 pg m−3) presented the highest levels in air, and showed seasonal fluctuation coinciding with the growing seasons. The relative proportion urban/(urban + rural) ranged from 0.4 to 0.7 showing no differences between urban and rural concentrations. Air back trajectories analysis showed air masses passing over agricultural fields and potentially enhancing the drift of pesticides into the urban sites. This study represents the first information regarding CUPs in the atmosphere of Tuscany region using PAS-PUF disk. - Highlights: • Current use pesticides (CUPs) were detected in the atmosphere of Tuscany, Italy. • Chlorpyrifos showed the highest concentrations in air with seasonal patterns. • CUPs levels might be influenced by agricultural activities. • No differences were detected between Urban and Rural sites. • Air mass analysis indicated the monitoring sites are influenced by local sources. - Seasonality of CUPs was measured in Tuscany, Italy. Chlorpyrifos showed the highest values. Urban and rural sites showed no differences. Agricultural activities influence CUPs levels in air

  18. Passive air sampler as a tool for long-term air pollution monitoring: Part 1. Performance assessment for seasonal and spatial variations

    International Nuclear Information System (INIS)

    The potential of passive air sampling devices (polyurethane foam disks) to assess the influence of local sources on the quality of the surrounding environment was investigated. DEZA Valasske Mezirici, a coal tar and mixed tar oils processing plant, and Spolana Neratovice, a chemical factory with the history of high production of organochlorinated pesticides (OCPs), were selected as the point sources of PAHs, and OCPs, respectively. Levels of PCBs, OCPs and PAHs were determined for all sampling sites and sampling periods. The study brought useful data about the air concentrations of POPs in the investigated regions. More important, it provided information on the transport and fate of POPs in the vicinity of local sources of contamination useful for the estimation of their influence. Very good capability of passive samplers to reflect temporal and spatial fluctuation in concentrations of persistent organic pollutants in the ambient air was confirmed which makes them applicable for monitoring on the local scale. - Passive air sampling techniques can indicate seasonal and spatial variations in the ambient concentrations of persistent organic compounds near point sources

  19. Assessment of the biodegradability of selected sulfa drugs in two polluted rivers in Poland: Effects of seasonal variations, accidental contamination, turbidity and salinity.

    Science.gov (United States)

    Adamek, Ewa; Baran, Wojciech; Sobczak, Andrzej

    2016-08-01

    The aim of our study was to assess the aerobic biodegradation of four selected sulfonamides (sulfanilamide, sulfamethoxazole, sulfadiazine and sulfathiazole) using water samples drawn from highly polluted rivers. Additionally, we aimed to identify the factors that have a significant effect on the process efficiency. The 19 water samples were collected from Brynica and Czarna Przemsza rivers (in Poland) at the same location at approximately monthly intervals. A characteristic feature of the results is the presence of significant differences between the rates of sulfonamides biodegradation in particular samples. The sulfonamide most resistant to biodegradation was sulfamethoxazole, whereas sulfathiazole was most biodegradable. Seasonal variations and related microbial population changes had the most significant effects on sulfonamides biodegradation, e.g., the studied process was highly inhibited during wintertime. A decrease in the biodegradation rate in the river water could be caused by an accidental water pollution by industrial wastewater with heavy metals, an increase in salinity and a decrease in pH, and turbidity. PMID:27060864

  20. Genomic variation in the MMP-1 promoter influences estrogen receptor mediated activity in a mechanically activated environment: potential implications for microgravity risk assessment

    Science.gov (United States)

    Thaler, John; Myers, Ken; Lu, Ting; Hart, David

    examine the potential impact of the 1G/2G SNP on the cellular response to mechanical loading. HIG-82 cells are estrogen receptor (ER) negative and were transiently transfected with SV40 expression vectors for either ER-α or ER-β isoforms. Cells grown on glass slides were also co-transfected with either a 1G or 2G MMP-1 promoter-luciferase construct. Transfected cells were subjected to dynamic shear stress in a Flexcell Streamer Shear Stress Device. The dynamic loading regime was 0.5 Hz, 10 dyn/cm2 shear for 1 minute followed by 14 minutes rest and repeated for 8 hrs. A Promega Dual Luciferase Reporter Assay System was used to assess MMP-1 promoter activity. Results: Shear stress loading increased both 1G and 2G MMP-1 promoter activity compared to unloaded controls, however the 2G promoter had significantly higher rates of expression than the 1G promoter across all loading regimes and ER co-transfections. Transfection with ER-β resulted in higher MMP-1 promoter activity than that in cells expressing ER-α or in ER-neg cells. Conclusions: Specific genomic variations can lead to differences in cellular responses to changes in mechanical loading environments such as are encountered in microgravity environments or earth-based analogs. These genomic differences may predispose individuals to greater risk of bone loss. It is important to understand the combined effects of mechanical loading, genetic variation and sex hormones on bone maintenance so that risks can be identified for microgravity or analog environments, and specific interventions developed to counteract such risk or even exclude some individuals from prolonged space environments due to the extent of the risk.

  1. Variational MCMC

    OpenAIRE

    De Freitas, Nando; Hojen-Sorensen, Pedro; Jordan, Michael I.; Russell, Stuart

    2013-01-01

    We propose a new class of learning algorithms that combines variational approximation and Markov chain Monte Carlo (MCMC) simulation. Naive algorithms that use the variational approximation as proposal distribution can perform poorly because this approximation tends to underestimate the true variance and other features of the data. We solve this problem by introducing more sophisticated MCMC algorithms. One of these algorithms is a mixture of two MCMC kernels: a random walk Metropolis kernel ...

  2. Developing Integrated Remote Sensing and Geographical Information Sciences Procedures to Assess Impacts of Climate Variations on Spatio-Temporal Distribution of Mangroves

    Science.gov (United States)

    Qaisar, Maha

    2016-07-01

    Pakistan's periled treasures of mangroves require protection from devastating anthropogenic activities, which can only be achieved through the identification and management of this habitat. The primary objective of this study is to identify the potential habitat of mangroves along the coastline of Pakistan with the help of Remote Sensing (RS) and Geographical Information System (GIS) techniques. Once the mangroves were identified, species of mangroves need to be separated through Object Based Image Analysis (OBIA) which gave the area of mangroves and non mangroves sites. Later other parameters of Sea Surface Temperature, Sea Surface Salinity, chlorophyll-a along with altimetry data were used to assess the climatic variations on the spatio-temporal distribution of mangroves. Since mangroves provide economical, ecological, biological indication of Coastal Change or Sea Level Rise. Therefore, this provides a strong platform to assess the climatic variations which are posing negative impacts on the mangroves ecosystem. The results indicate that mangroves are present throughout along the coastline, proving that Pakistan is rich in these diverse ecosystems. Pakistan being at important geo strategic position can also benefit from its vast mangroves and other coastal resources such as coral reefs and fish varieties. Moreover, coastal zone management through involvement of the local community and establishment of Marine Protected Area (MPA) is the need of the hour to avoid deforestation of mangroves, which can prove to be deadly damaging for the fish populace since it provides habitats to various marine animals. However, the established relationship among SST, SSS, chlorophyll-a and altimetry data assisted to know the suitable sites for mangroves. But due to enhanced climatic impacts these relationships are distorted which has posed devastating effects on the growth and distribution of mangroves. Study area was Karachi Coast, Pakistan. The total area of Karachi is about 70

  3. Variational analysis

    CERN Document Server

    Rockafellar, R Tyrrell

    1998-01-01

    From its origins in the minimization of integral functionals, the notion of 'variations' has evolved greatly in connection with applications in optimization, equilibrium, and control. It refers not only to constrained movement away from a point, but also to modes of perturbation and approximation that are best describable by 'set convergence', variational convergence of functions and the like. This book develops a unified framework and, in finite dimension, provides a detailed exposition of variational geometry and subdifferential calculus in their current forms beyond classical and convex analysis. Also covered are set-convergence, set-valued mappings, epi-convergence, duality, maximal monotone mappings, second-order subderivatives, measurable selections and normal integrands. The changes in this 3rd printing mainly concern various typographical corrections, and reference omissions that came to light in the previous printings. Many of these reached the authors' notice through their own re-reading, that of th...

  4. Assessing the value of multi-receiver low-frequency electromagnetic-induction (EMI) measurement for assessing variation in soil moisture content in field experiments with winter wheat (Triticum aestivum)

    Science.gov (United States)

    Shanahan, Peter; Binley, Andrew; Dodd, Ian; Whalley, Richard; Watts, Chris; Ashton, Rhys; Ober, Eric

    2014-05-01

    In large plant breeding field trials with multiple genotypes, measuring soil water status (an indicator of crop water uptake) by conventional techniques (e.g. core extraction and penetration resistance) is limited by the cost and effort needed to achieve sufficient replication to apply robust statistical analysis. Geophysical methods may provide a more cost-effective means of more assessing valuable information about soil water status for such studies. We present here results from a field experiment using geophysical techniques for remote mapping of soil water content on sandy loam and silt loam soils in spring/summer 2013 in the UK. The aim of the study was to assess electromagnetic-induction (EMI) conductivity measurements for sensitivity to variations in shallow soil electrical properties and the spatial and temporal mapping of soil water. The CMD Mini-Explorer (GF Instruments) operates with three receiver coils at fixed distances from a transmitter coil (0.32 m, 0.71 m, 1.2 m). Measurement of magnetic field quadrature in horizontal coplanar (HC) and vertical coplanar (VC) of the three receiver coils provides six depths of investigation for the given coil spacing cumulative sensitivities. At the two field sites the instrument was applied to measuring apparent electrical conductivity (ECa) below 7.0 x 1.8 m plots consisting of 23 rain fed winter wheat cultivars and bare soil fallow control plots. These plots were sown in March 2013 and organised into a randomised block design. Electrical resistivity tomography (ERT) surveys along 15 m transects were also conducted at the two sites in order to compare EMI measured ECa. Our results show that progressive soil drying at both sites due to crop uptake significantly decreased (p<0.05) soil ECa. The difference in soil ECa as a result of water uptake between cultivars was found to be significant (p<0.05) from one of the coil configurations (coil spacing 1.8m in HC mode), and only at the silty loam site (no significant

  5. Variational principles

    CERN Document Server

    Moiseiwitsch, B L

    2004-01-01

    This graduate-level text's primary objective is to demonstrate the expression of the equations of the various branches of mathematical physics in the succinct and elegant form of variational principles (and thereby illuminate their interrelationship). Its related intentions are to show how variational principles may be employed to determine the discrete eigenvalues for stationary state problems and to illustrate how to find the values of quantities (such as the phase shifts) that arise in the theory of scattering. Chapter-by-chapter treatment consists of analytical dynamics; optics, wave mecha

  6. Assets at Risk: Menstrual Cycle Variation in the Envisioned Formidability of a Potential Sexual Assailant Reveals a Component of Threat Assessment

    OpenAIRE

    Fessler, Daniel M.T.; Holbrook, Colin; Fleischman, Diana Santos

    2014-01-01

    Situations of potential agonistic conflict demand rapid and effective decision-making. The process of threat assessment includes assessments of relative fighting capacity, assessments of the likelihood of attack, and assessments of the extent to which one′s assets are at risk. The dimensions of physical size and strength appear to serve as key parameters in a cognitive representation summarizing multiple constituents of threat assessment. Here, we examine the thesis that this same representat...

  7. Relative Biological Effectiveness Variation Along Monoenergetic and Modulated Bragg Peaks of a 62-MeV Therapeutic Proton Beam: A Preclinical Assessment

    OpenAIRE

    Chaudhary, Pankaj; I Marshall, Thomas; Perozziello, Francesca M; Manti, Lorenzo; Currell, Frederick J.; Hanton, Fiona; McMahon, Stephen J; Kavanagh, Joy N.; Cirrone, Giuseppe Antonio Pablo; Romano, Francesco; Prise, Kevin M.; SCHETTINO, Giuseppe

    2014-01-01

    iological optimization of proton therapy critically depends on detailed evaluation of relative biological effectiveness (RBE) variations along the Bragg curve. The clinically accepted RBE value of 1.1 is an oversimplification, which disregards the steep rise of linear energy transfer (LET) at the distal end of the spread-out Bragg peak. We observed significant cell killing RBE variations dependent on beam modulation, intrinsic radiosensitivity, and LET in agreement with the LEM predicted valu...

  8. Diurnal Variation and Spatial Distribution Effects on Sulfur Speciation in Aerosol Samples as Assessed by X-Ray Absorption Near-Edge Structure (XANES)

    OpenAIRE

    Siwatt Pongpiachan; Kanjana Thumanu; Warangkana Na Pattalung; Phoosak Hirunyatrakul; Itthipon Kittikoon; Kin Fai Ho; Junji Cao

    2012-01-01

    This paper focuses on providing new results relating to the impacts of Diurnal variation, Vertical distribution, and Emission source on sulfur K-edge XANES spectrum of aerosol samples. All aerosol samples used in the diurnal variation experiment were preserved using anoxic preservation stainless cylinders (APSCs) and pressure-controlled glove boxes (PCGBs), which were specially designed to prevent oxidation of the sulfur states in PM10. Further investigation of sulfur K-edge XANES spectra rev...

  9. The ecological complexity of the Thai-Laos Mekong River: I. Geology, seasonal variation and human impact assessment on river quality.

    Science.gov (United States)

    Udomchoke, Veerasak; Sunthornranun, Patcharee; Songsasen, Apisit; Phanwichien, Kantimanee; Jiwapornkupt, Pongsakorn; Homchan, Unop; Lauhachinda, Nitaya; Sakultantimetha, Arthit; Bangkedphol, Sornnarin; Torrance, Keith; Gibson, Mark D; Gaines, Alec F; Booth, Peter H; Keenan, Helen E

    2010-11-01

    The objective of this study is to assess the variation of pollution in the Thai-Laos Mekong associated with seasonal dynamics concomitant with the natural geological features and human activities that impact on the adverse quality of the river. The complex ecology of the 1500 km stretch of the Thai-Laos Mekong River has been studied in this paper to understand the relationship with the geomorphology, with the sub-tropical monsoonal climate and the impact of human activity. Sub-surface geology controls the nature and extent of the drainage basin and of the river channel. The volume flow of the river varies naturally and dynamically in phase with the rainfall; traditional models based on steady state hydraulics are inappropriate. Continuous erosion of the river banks and bed generates a sediment load of impure silt, mica, quartz and clay minerals that inhibits light penetration and limits the primary productivity of the river. The river separates two countries at different stages of development; it flows through or close to eight non-industrial conurbations (Populations 350,000-2,000,000) but is otherwise sparsely populated. The river is used for subsistence agriculture, village transport, fishing including aquaculture and as a source of domestic water. Hydroelectricity is generated from the Laos tributaries. The river is a depository for partially treated urban waste and untreated village waste, hence populations of E.coli bacteria sometimes render the water unsuitable for drinking unless treated with the highest value of 240/100 ml found at station 7 during the summer season of 2003. Furthermore the river is polluted by trace metals, notably cadmium and mercury, and by Polycyclic Aromatic Hydrocarbons (PAHs), which are particularly concentrated in the sediments. Previous work has shown that cadmium and mercury exceed the Probable Effect Level (PEL) values of Canadian Environmental Quality Guidelines and that the PAH concentrations were also greater than the Interim

  10. Assessment

    Institute of Scientific and Technical Information of China (English)

    Geoff Brindley

    2005-01-01

    @@ Introduction TERMINOLOGY AND KEY CONCEPTS The term assessment refers to a variety of ways of collecting information on a learner's language ability or achievement. Although testing and assessment are often used interchangeably, the latter is an umbrella term encompassing measurement instruments administered on a ‘one-off’ basis such as tests, as well as qualitative methods of monitoring and recording student learning such as observation, simulations of project work. Assessment is also distinguished from evaluation which is concerned with the overall language programme and not just with what individual students have learnt. Proficiency assessment refers to the assessment of general language abilities acquired by the learner independent of a course of study.This kind of assessment is often done through the administration of standardised commercial language-proficency tests. On the other hand, assessment of achievement aims to establish what a student had learned in relation to a particular course or curriculum (thus frequently carried out by the teacher) .Achievement assesssment may be based either on the specific content of the course or on the course objectives (Hughes 1989).

  11. Development of NIR calibration models to assess year-to-year variation in total non-structural carbohydrates in grasses using PLSR

    DEFF Research Database (Denmark)

    Shetty, Nisha; Gislum, René; Jensen, Anne Mette Dahl;

    2012-01-01

    Near-infrared (NIR) spectroscopy was used in combination with chemometrics to quantify total nonstructural carbohydrates (TNC) in grass samples in order to overcome year-to-year variation. A total of 1103 above-ground plant and root samples were collected from different field and pot experiments...... in order to improve model performance, but still it was not possible to avoid year-to-year variation using iPLS, however iPLS simplified the interpretation of the regression model. The best option was to expand the database with samples from a new year, to include these samples in the calibration...

  12. Assessment of the magnitude of geographical variations in the duration of non-work-related sickness absence by individual and contextual factors

    Directory of Open Access Journals (Sweden)

    Isabel Torá-Rocamora

    2015-05-01

    Conclusions: County-level variation in the duration of NWRSA was small and was explained more by individual than by contextual variables. Knowledge of geographic differences in NWRSA duration is needed to plan specific programs and interventions to minimize these differences.

  13. A holistic high-throughput screening framework for biofuel feedstock assessment that characterises variations in soluble sugars and cell wall composition in Sorghum bicolor

    OpenAIRE

    Martin, Antony P.; PALMER, WILLIAM M.; Byrt, Caitlin S; Furbank, Robert T.; Grof, Christopher PL

    2013-01-01

    Background A major hindrance to the development of high yielding biofuel feedstocks is the ability to rapidly assess large populations for fermentable sugar yields. Whilst recent advances have outlined methods for the rapid assessment of biomass saccharification efficiency, none take into account the total biomass, or the soluble sugar fraction of the plant. Here we present a holistic high-throughput methodology for assessing sweet Sorghum bicolor feedstocks at 10 days post-anthesis for total...

  14. Delicious words – Assessing the impact of short storytelling messages on consumer preferences for variations of a new processed meat product

    DEFF Research Database (Denmark)

    Fenger, Morten H. J.; Aschemann-Witzel, Jessica; Hansen, Flemming;

    2015-01-01

    Continuous food product improvements require communication that induces consumers to test the new products. The paper presents an experiment that investigated the characteristics of consumers who reacted positively to variations of a new meat product, and explores the effect of short storytelling...... messages on choice. 1087 Danish consumers were presented with binary choice sets consisting of conventional and new variations of a cubed ham product; half of the respondents in addition saw short storytelling messages. It was found that while some consumers – especially those characterized by values...... related to stimulation seeking and hedonism and with a tendency towards variety seeking – reacted positively to the new product, others were less interested. The introduction of elements of storytelling, however, had a favorable effect on choice for the segment previously less interested. Thus, the...

  15. Relative Biological Effectiveness Variation Along Monoenergetic and Modulated Bragg Peaks of a 62-MeV Therapeutic Proton Beam: A Preclinical Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Chaudhary, Pankaj; Marshall, Thomas I. [Centre for Cancer Research and Cell Biology, School of Medicine, Dentistry and Biomedical Sciences, Queen' s University Belfast, Belfast (United Kingdom); Perozziello, Francesca M.; Manti, Lorenzo [Department of Physics, University of Naples Federico II and INFN Naples Section University of Naples, Naples (Italy); Currell, Frederick J.; Hanton, Fiona [Centre for Plasma Physics, School of Mathematics and Physics, Queen' s University Belfast, Belfast (United Kingdom); McMahon, Stephen J.; Kavanagh, Joy N. [Centre for Cancer Research and Cell Biology, School of Medicine, Dentistry and Biomedical Sciences, Queen' s University Belfast, Belfast (United Kingdom); Cirrone, Giuseppe Antonio Pablo; Romano, Francesco [Istituto Nazionale di Fisica Nucleare, LNS, Catania (Italy); Prise, Kevin M., E-mail: k.prise@qub.ac.uk [Centre for Cancer Research and Cell Biology, School of Medicine, Dentistry and Biomedical Sciences, Queen' s University Belfast, Belfast (United Kingdom); Schettino, Giuseppe [Centre for Cancer Research and Cell Biology, School of Medicine, Dentistry and Biomedical Sciences, Queen' s University Belfast, Belfast (United Kingdom); National Physical Laboratory, Teddington (United Kingdom)

    2014-09-01

    Purpose: The biological optimization of proton therapy can be achieved only through a detailed evaluation of relative biological effectiveness (RBE) variations along the full range of the Bragg curve. The clinically used RBE value of 1.1 represents a broad average, which disregards the steep rise of linear energy transfer (LET) at the distal end of the spread-out Bragg peak (SOBP). With particular attention to the key endpoint of cell survival, our work presents a comparative investigation of cell killing RBE variations along monoenergetic (pristine) and modulated (SOBP) beams using human normal and radioresistant cells with the aim to investigate the RBE dependence on LET and intrinsic radiosensitvity. Methods and Materials: Human fibroblasts (AG01522) and glioma (U87) cells were irradiated at 6 depth positions along pristine and modulated 62-MeV proton beams at the INFN-LNS (Catania, Italy). Cell killing RBE variations were measured using standard clonogenic assays and were further validated using Monte Carlo simulations and the local effect model (LEM). Results: We observed significant cell killing RBE variations along the proton beam path, particularly in the distal region showing strong dose dependence. Experimental RBE values were in excellent agreement with the LEM predicted values, indicating dose-averaged LET as a suitable predictor of proton biological effectiveness. Data were also used to validate a parameterized RBE model. Conclusions: The predicted biological dose delivered to a tumor region, based on the variable RBE inferred from the data, varies significantly with respect to the clinically used constant RBE of 1.1. The significant RBE increase at the distal end suggests also a potential to enhance optimization of treatment modalities such as LET painting of hypoxic tumors. The study highlights the limitation of adoption of a constant RBE for proton therapy and suggests approaches for fast implementation of RBE models in treatment planning.

  16. Assessment of somaclonal variation in somatic embryo-derived plants of yacon [Smallanthus sonchifolius (Poepp. and Endl.) H. Robinson] using inter simple sequence repeat analysis and flow cytometry

    OpenAIRE

    Viehmannová, I.; Bortlová, Z.; Vítámvás, J.; Čepková, P.; Eliášová, K. (Kateřina); Svobodová, E.; Trávníčková, M.

    2014-01-01

    Background: Yacon (Smallanthus sonchifolius) is a root crop native to the Andean region. Low sexual reproductive capacity is a major constraint facing the genetic breeding of this crop. Biotechnological techniques offer alternative ways to widen genetic variability. We investigated somaclonal variation in regenerants of yacon derived from in vitro somatic embryogenesis using simple sequence repeat (ISSR) analysis and flow cytometry. Results: Twenty tested ISSR primers provided a total of ...

  17. Relative Biological Effectiveness Variation Along Monoenergetic and Modulated Bragg Peaks of a 62-MeV Therapeutic Proton Beam: A Preclinical Assessment

    International Nuclear Information System (INIS)

    Purpose: The biological optimization of proton therapy can be achieved only through a detailed evaluation of relative biological effectiveness (RBE) variations along the full range of the Bragg curve. The clinically used RBE value of 1.1 represents a broad average, which disregards the steep rise of linear energy transfer (LET) at the distal end of the spread-out Bragg peak (SOBP). With particular attention to the key endpoint of cell survival, our work presents a comparative investigation of cell killing RBE variations along monoenergetic (pristine) and modulated (SOBP) beams using human normal and radioresistant cells with the aim to investigate the RBE dependence on LET and intrinsic radiosensitvity. Methods and Materials: Human fibroblasts (AG01522) and glioma (U87) cells were irradiated at 6 depth positions along pristine and modulated 62-MeV proton beams at the INFN-LNS (Catania, Italy). Cell killing RBE variations were measured using standard clonogenic assays and were further validated using Monte Carlo simulations and the local effect model (LEM). Results: We observed significant cell killing RBE variations along the proton beam path, particularly in the distal region showing strong dose dependence. Experimental RBE values were in excellent agreement with the LEM predicted values, indicating dose-averaged LET as a suitable predictor of proton biological effectiveness. Data were also used to validate a parameterized RBE model. Conclusions: The predicted biological dose delivered to a tumor region, based on the variable RBE inferred from the data, varies significantly with respect to the clinically used constant RBE of 1.1. The significant RBE increase at the distal end suggests also a potential to enhance optimization of treatment modalities such as LET painting of hypoxic tumors. The study highlights the limitation of adoption of a constant RBE for proton therapy and suggests approaches for fast implementation of RBE models in treatment planning

  18. Temporal variation of soil moisture over the Wuding River Basin assessed with an eco-hydrological model, in-situ observations and remote sensing

    Directory of Open Access Journals (Sweden)

    S. Liu

    2008-12-01

    Full Text Available For integrative management of soil and water in the Wuding River basin, Loess plateau, China, where severe soil erosion damages are incurred, the ecohydrological behavior of the region is needed to be explored. In this study we focus on the evolution of soil moisture (SM in the basin. Since there are only twelve years in-situ SM measurements available at two stations from 1992 to 2004, an eco-hydrological processes-based model (VIP, Vegetation Interface Processes model is employed to simulate the long-term SM, evapotranspiration (ET, vegetation cover and production variation from 1956 to 2004, for the mechanical analysis of SM change. In-situ SM observations and a remotely sensed SM dataset retrieved by the Vienna University of Technology are used to validate the model. The results show that the model is able to capture seasonal SM variations. The seasonal pattern, multi-year variation, standard deviation and CV (coefficient of the variation of SM at the daily, monthly and annual scale are well explained by the climatic and ecological factors such as precipitation, temperature, net radiation, evapotranspiration, and Leaf Area Index (LAI, denoted as LAI. The annual and inter-annual variability of SM is the lowest comparing with that for other 11-ecohydrological variables. The trend analysis shows that SM is in decreasing tendency at ∝=0.01 level of significance. Its significance is lower than that of runoff and that of temperature (∝=0.001, whereas higher than that of precipitation (∝=0.1. The products of these long-term SM data aim to help integrative management of soil and water resources.

  19. Assessment

    Directory of Open Access Journals (Sweden)

    D.F. Cortés-Rojas

    2016-07-01

    Full Text Available Spray drying has been successfully employed for the encapsulation of herbal bioactive compounds resulting in stable phytopharmaceutical preparations. Bidens pilosa L. is a South American medicinal plant with proved antimalaric, hepatoprotector and antioxidant activities, generally linked to their secondary metabolites, flavonoids and polyacetylenes. In this work the physicochemical stability of an optimized spray dried composition from a B. pilosa extract was evaluated at three different stress storage conditions in open containers and in sealed sachets. High performance liquid chromatography was employed to monitor the concentration of three marker compounds over 12 months. Color variation of the stored samples was evaluated by using a color spectrophotometer. It was observed that the concentration of the monitored compounds of the plant decreases more drastically in samples stored in open containers. The two flavonoids monitored, rutin and hyperoside, showed lower degradation than the polyacetylene. The concentration of the markers did not change significantly at the lowest temperature. With regard to color, darker hues were observed at higher temperatures and storage times. This study showed that the storage conditions cause significant impact on stability of standardized spray dried B. pilosa extract.

  20. Temporal variation of soil moisture over the Wuding River basin assessed with an eco-hydrological model, in-situ observations and remote sensing

    Science.gov (United States)

    Liu, S.; Mo, X.; Zhao, W.; Naeimi, V.; Dai, D.; Shu, C.; Mao, L.

    2009-07-01

    The change pattern and trend of soil moisture (SM) in the Wuding River basin, Loess Plateau, China is explored based on the simulated long-term SM data from 1956 to 2004 using an eco-hydrological process-based model, Vegetation Interface Processes model, VIP. In-situ SM observations together with a remotely sensed SM dataset retrieved by the Vienna University of Technology are used to validate the model. In the VIP model, climate-eco-hydrological (CEH) variables such as precipitation, air temperature and runoff observations and also simulated evapotranspiration (ET), leaf area index (LAI), and vegetation production are used to analyze the soil moisture evolution mechanism. The results show that the model is able to capture seasonal SM variations. The seasonal pattern, multi-year variation, standard deviation and coefficient of variation (CV) of SM at the daily, monthly and annual scale are well explained by CEH variables. The annual and inter-annual variability of SM is the lowest compared with that of other CEH variables. The trend analysis shows that SM is in decreasing tendency at α=0.01 level of significance, confirming the Northern Drying phenomenon. This trend can be well explained by the decreasing tendency of precipitation (α=0.1) and increasing tendency of temperature (α=0.01). The decreasing tendency of runoff has higher significance level (α=0.001). Because of SM's decreasing tendency, soil evaporation (ES) is also decreasing (α=0.05). The tendency of net radiation (Rn), evapotranspiration (ET), transpiration (EC), canopy intercept (EI) is not obvious. Net primary productivity (NPP), of which the significance level is lower than α=0.1, and gross primary productivity (GPP) at α=0.01 are in increasing tendency.

  1. Bladder filling variations during concurrent chemotherapy and pelvic radiotherapy in rectal cancer patients: early experience of bladder volume assessment using ultrasound scanner

    International Nuclear Information System (INIS)

    To describe the early experience of analyzing variations and time trends in bladder volume of the rectal cancer patients who received bladder ultrasound scan. We identified 20 consecutive rectal cancer patients who received whole pelvic radiotherapy (RT) and bladder ultrasound scan between February and April 2012. Before simulation and during the entire course of treatment, patients were scanned with portable automated ultrasonic bladder scanner, 5 times consecutively, and the median value was reported. Then a radiation oncologist contoured the bladder inner wall shown on simulation computed tomography (CT) and calculated its volume. Before simulation, the median bladder volume measured using simulation CT and bladder ultrasound scan was 427 mL (range, 74 to 1,172 mL) and 417 mL (range, 147 to 1,245 mL), respectively. There was strong linear correlation (R = 0.93, p < 0.001) between the two results. During the course of treatment, there were wide variations in the bladder volume and every time, measurements were below the baseline with statistical significance (12/16). At 6 weeks after RT, the median volume was reduced by 59.3% to 175 mL. Compared to the baseline, bladder volume was reduced by 38% or 161 mL on average every week for 6 weeks. To our knowledge, this study is the first to prove that there are bladder volume variations and a reduction in bladder volume in rectal cancer patients. Moreover, our results will serve as the basis for implementation of bladder training to patients receiving RT with full bladder.

  2. Variations in the work function of doped single- and few-layer graphene assessed by Kelvin probe force microscopy and density functional theory

    OpenAIRE

    Ziegler, D; Gava, P.; Guettinger, J.; Molitor, F; Wirtz, Ludger; Lazzeri, M.; Saitta, A. M.; Stemmer, A.; Mauri, F; Stampfer, C.

    2011-01-01

    We present Kelvin probe force microscopy measurements of single-and few-layer graphene resting on SiO2 substrates. We compare the layer thickness dependency of the measured surface potential with ab initio density functional theory calculations of the work function for substrate-doped graphene. The ab initio calculations show that the work function of single-and bilayer graphene is mainly given by a variation of the Fermi energy with respect to the Dirac point energy as a function of doping, ...

  3. A comprehensive assessment of mercury exposure in penguin populations throughout the Southern Hemisphere: Using trophic calculations to identify sources of population-level variation

    International Nuclear Information System (INIS)

    Highlights: • Mercury concentrations documented for 10 species of penguins (26 breeding populations). • Mercury concentrations ⩽2.00 ppm in feathers from 18/26 penguin populations. • Trophic level calculations revealed source of population-level variation in mercury. • First documentation of geographic mercury ‘hotspots’ for penguin populations. - Abstract: The wide geographic distribution of penguins (Order Sphenisciformes) throughout the Southern Hemisphere provided a unique opportunity to use a single taxonomic group as biomonitors of mercury among geographically distinct marine ecosystems. Mercury concentrations were compared among ten species of penguins representing 26 geographically distinct breeding populations. Mercury concentrations were relatively low (⩽2.00 ppm) in feathers from 18/26 populations considered. Population-level differences in trophic level explained variation in mercury concentrations among Little, King, and Gentoo penguin populations. However, Southern Rockhopper and Magellanic penguins breeding on Staten Island, Tierra del Fuego, had the highest mercury concentrations relative to their conspecifics despite foraging at a lower trophic level. The concurrent use of stable isotope and mercury data allowed us to document penguin populations at the greatest risk of exposure to harmful concentrations of mercury as a result of foraging at a high trophic level or in geographic ‘hot spots’ of mercury availability

  4. Assessing spatiotemporal variation of drought in China and its impact on agriculture during 1982-2011 by using PDSI indices and agriculture drought survey data

    Science.gov (United States)

    Yan, Hao; Wang, Shao-Qiang; Wang, Jun-Bang; Lu, Hou-Quan; Guo, An-Hong; Zhu, Zai-Chun; Myneni, Ranga B.; Shugart, Herman H.

    2016-03-01

    Inspired by concerns of the effects of a warming climate, drought variation and its impacts have gained much attention in China. Arguments about China's drought persist and little work has utilized agricultural drought survey area to evaluate the impact of natural drought on agriculture. Based on a newly revised self-calibrating Palmer Drought Severity Index (PDSI) model driven with air-relative-humidity-based two-source (ARTS) E0 (PDSIARTS; Yan et al., 2014), spatial and temporal variations of drought were analyzed for 1982-2011 in China, which indicates that there was nonsignificant change of drought over this interval but with an extreme drought event happened in 2000-2001. However, using air temperature (Ta)-based Thornthwaite potential evaporation (EP_Th) and Penman-Monteith potential evaporation (EP_PM) to drive the PDSI model, their corresponding PDSITh and PDSIPM all gave a significant drying trend for 1982-2011. This suggests that PDSI model was sensitive to EP parameterization in China. Annual drought-covered area from agriculture survey was initially adopted to evaluate impact of PDSI drought on agriculture in China during 1982-2011. The results indicate that PDSIARTS drought area (defined as PDSIARTS climate factors dominated the interannual changes of agriculture drought area, while PDSITh and PDSIPM drought areas had no relationship with the agriculture drought-covered area and overestimated the uptrend of agriculture drought This study highlights the importance of coupling PDSI with drought survey data in evaluating the impact of natural drought on agriculture.

  5. Application of PCR amplicon sequencing using a single primer pair in PCR amplification to assess variations in Helicobacter pylori CagA EPIYA tyrosine phosphorylation motifs

    Directory of Open Access Journals (Sweden)

    Karlsson Anneli

    2010-02-01

    Full Text Available Abstract Background The presence of various EPIYA tyrosine phosphorylation motifs in the CagA protein of Helicobacter pylori has been suggested to contribute to pathogenesis in adults. In this study, a unique PCR assay and sequencing strategy was developed to establish the number and variation of cagA EPIYA motifs. Findings MDA-DNA derived from gastric biopsy specimens from eleven subjects with gastritis was used with M13- and T7-sequence-tagged primers for amplification of the cagA EPIYA motif region. Automated capillary electrophoresis using a high resolution kit and amplicon sequencing confirmed variations in the cagA EPIYA motif region. In nine cases, sequencing revealed the presence of AB, ABC, or ABCC (Western type cagA EPIYA motif, respectively. In two cases, double cagA EPIYA motifs were detected (ABC/ABCC or ABC/AB, indicating the presence of two H. pylori strains in the same biopsy. Conclusion Automated capillary electrophoresis and Amplicon sequencing using a single, M13- and T7-sequence-tagged primer pair in PCR amplification enabled a rapid molecular typing of cagA EPIYA motifs. Moreover, the techniques described allowed for a rapid detection of mixed H. pylori strains present in the same biopsy specimen.

  6. Temporal variation of soil moisture over the Wuding River basin assessed with an eco-hydrological model, in-situ observations and remote sensing

    Directory of Open Access Journals (Sweden)

    C. Shu

    2009-07-01

    Full Text Available The change pattern and trend of soil moisture (SM in the Wuding River basin, Loess Plateau, China is explored based on the simulated long-term SM data from 1956 to 2004 using an eco-hydrological process-based model, Vegetation Interface Processes model, VIP. In-situ SM observations together with a remotely sensed SM dataset retrieved by the Vienna University of Technology are used to validate the model. In the VIP model, climate-eco-hydrological (CEH variables such as precipitation, air temperature and runoff observations and also simulated evapotranspiration (ET, leaf area index (LAI, and vegetation production are used to analyze the soil moisture evolution mechanism. The results show that the model is able to capture seasonal SM variations. The seasonal pattern, multi-year variation, standard deviation and coefficient of variation (CV of SM at the daily, monthly and annual scale are well explained by CEH variables. The annual and inter-annual variability of SM is the lowest compared with that of other CEH variables. The trend analysis shows that SM is in decreasing tendency at α=0.01 level of significance, confirming the Northern Drying phenomenon. This trend can be well explained by the decreasing tendency of precipitation (α=0.1 and increasing tendency of temperature (α=0.01. The decreasing tendency of runoff has higher significance level (α=0.001. Because of SM's decreasing tendency, soil evaporation (ES is also decreasing (α=0.05. The tendency of net radiation (Rn, evapotranspiration (ET, transpiration (EC, canopy intercept (EI is not obvious. Net primary productivity (NPP, of which the significance level is lower than α=0.1, and gross primary productivity (GPP at α=0.01 are in increasing tendency.

  7. Using ecological momentary assessment to investigate short-term variations in sexual functioning in a sample of peri-menopausal women from Iran.

    Science.gov (United States)

    Pakpour, Amir H; Yekaninejad, Mir Saeed; Pallich, Gianandrea; Burri, Andrea

    2015-01-01

    The investigation of short-term changes in female sexual functioning has received little attention so far. The aims of the study were to gain empirical knowledge on within-subject and within- and across-variable fluctuations in women's sexual functioning over time. More specifically, to investigate the stability of women´s self-reported sexual functioning and the moderating effects of contextual and interpersonal factors. A convenience sample of 206 women, recruited across eight Health care Clinics in Rasht, Iran. Ecological momentary assessment was used to examine fluctuations of sexual functioning over a six week period. A shortened version of the Female Sexual Function Index (FSFI) was applied to assess sexual functioning. Self-constructed questions were included to assess relationship satisfaction, partner's sexual performance and stress levels. Mixed linear two-level model analyses revealed a link between orgasm and relationship satisfaction (Beta = 0.125, P = 0.074) with this link varying significantly between women. Analyses further revealed a significant negative association between stress and all six domains of women's sexual functioning. Women not only reported differing levels of stress over the course of the assessment period, but further differed from each other in how much stress they experienced and how much this influenced their sexual response. Orgasm and sexual satisfaction were both significantly associated with all other domains of sexual function (Pfactors and relationship factors. Consideration of these criteria is important and necessary for clinicians when diagnosing FSD. PMID:25692787

  8. Quantifying variation in 7Be depth distribution under simulated rainfall for an increased understanding of fallout radionuclide use in erosion assessments

    Science.gov (United States)

    Ryken, Nick; Al-Barri, Bashar; Blake, William; Taylor, Alex; Boeckx, Pascal; Verdoodt, Ann

    2015-04-01

    Models for the use of 7Be as a sediment tracer are all based on the observed depth distribution of 7Be and the derived relaxation mass depth (h0). Spatial variations in h0 however are not quantified, although this could have major implications for model application. In this study, 18 undisturbed soil cores (9.5 cm diameter, 7 cm depth) were collected at 2 reference locations, located 200 m from each other, near the field of interest (Nukerke, East Flanders, Belgium). Both locations were bare at time of sampling. Laboratory rainfall simulations with Be enriched water (0.5 mg/l) were performed on 16 of the undisturbed soil cores. After 3 rainfall simulations (30 minutes, average intensity 43 mm/h), the soil cores were cut in depth increments of 1.5 mm for Be analysis with ICP-OES after aqua regia digestion. The observed variation in depth distribution, and thus h0, was used for a model sensitivity analysis on a collected 7Be data set at an erosion plot nearby (Nukerke). Further, section cores for 7Be analysis were collected at both sites using 2 sectioning strategies, namely sectioning of undisturbed soil cores by a fine soil increment collector (FSIC) in the lab and in-field sectioning by scraping thin soil layers. Depth distributions of 7Be are measured by a high purity germanium gamma detector and strategies of sampling compared. Comparison of both sectioning strategies revealed that scraping soil layers resulted in higher 7Be activities at all depths, most likely due to contamination from the upper layers during the scraping process. With the use of a FSIC, precise fine soil increments could be collected more accurately. The variation in Be depth distribution after the rainfall simulations was studied within and between the reference sites. The depth distribution proved to be very similar among the different sampling sites within the first location (X), whereas more variation was measured within the second location (Y). When comparing both locations a general

  9. A comprehensive assessment of mercury exposure in penguin populations throughout the Southern Hemisphere: Using trophic calculations to identify sources of population-level variation.

    Science.gov (United States)

    Brasso, Rebecka L; Chiaradia, André; Polito, Michael J; Raya Rey, Andrea; Emslie, Steven D

    2015-08-15

    The wide geographic distribution of penguins (Order Sphenisciformes) throughout the Southern Hemisphere provided a unique opportunity to use a single taxonomic group as biomonitors of mercury among geographically distinct marine ecosystems. Mercury concentrations were compared among ten species of penguins representing 26 geographically distinct breeding populations. Mercury concentrations were relatively low (⩽2.00ppm) in feathers from 18/26 populations considered. Population-level differences in trophic level explained variation in mercury concentrations among Little, King, and Gentoo penguin populations. However, Southern Rockhopper and Magellanic penguins breeding on Staten Island, Tierra del Fuego, had the highest mercury concentrations relative to their conspecifics despite foraging at a lower trophic level. The concurrent use of stable isotope and mercury data allowed us to document penguin populations at the greatest risk of exposure to harmful concentrations of mercury as a result of foraging at a high trophic level or in geographic 'hot spots' of mercury availability. PMID:26072048

  10. Assessment of total and organic vanadium levels and their bioaccumulation in edible sea cucumbers: tissues distribution, inter-species-specific, locational differences and seasonal variations.

    Science.gov (United States)

    Liu, Yanjun; Zhou, Qingxin; Xu, Jie; Xue, Yong; Liu, Xiaofang; Wang, Jingfeng; Xue, Changhu

    2016-02-01

    The objective of this study is to investigate the levels, inter-species-specific, locational differences and seasonal variations of vanadium in sea cucumbers and to validate further several potential factors controlling the distribution of metals in sea cucumbers. Vanadium levels were evaluated in samples of edible sea cucumbers and were demonstrated exhibit differences in different seasons, species and sampling sites. High vanadium concentrations were measured in the sea cucumbers, and all of the vanadium detected was in an organic form. Mean vanadium concentrations were considerably higher in the blood (sea cucumber) than in the other studied tissues. The highest concentration of vanadium (2.56 μg g(-1)), as well as a higher degree of organic vanadium (85.5 %), was observed in the Holothuria scabra samples compared with all other samples. Vanadium levels in Apostichopus japonicus from Bohai Bay and Yellow Sea have marked seasonal variations. Average values of 1.09 μg g(-1) of total vanadium and 0.79 μg g(-1) of organic vanadium were obtained in various species of sea cucumbers. Significant positive correlations between vanadium in the seawater and V org in the sea cucumber (r = 81.67 %, p = 0.00), as well as between vanadium in the sediment and V org in the sea cucumber (r = 77.98 %, p = 0.00), were observed. Vanadium concentrations depend on the seasons (salinity, temperature), species, sampling sites and seawater environment (seawater, sediment). Given the adverse toxicological effects of inorganic vanadium and positive roles in controlling the development of diabetes in humans, a regular monitoring programme of vanadium content in edible sea cucumbers can be recommended. PMID:25732906

  11. Genetic variation in seedling water-use efficiency of Patagonian Cypress populations from contrasting precipitation regimes assessed through carbon isotope discrimination

    Energy Technology Data Exchange (ETDEWEB)

    Pastorino, M. J.; Aparicio, A. G.; Marchelli, P.; Gallo, L. A.

    2012-11-01

    Water-use efficiency (WUE) is a physiological parameter that plays a significant role in the evolutionary dynamics of many forest tree species. It can be estimated indirectly through carbon isotope discrimination (A). In general, plants of more arid origins have lower values of A. In order to study the degree of genetic control of this parameter and the genetic variation in A of Patagonian Cypress seedlings, three Argentinean natural populations chosen to represent two contrasting precipitation regimes were sampled in a common garden trial. The dry situation was represented by two neighboring marginal forest patches from the steppe, while the humid condition was represented by a population with 1,200 mm higher mean annual precipitation. Height (H) and A were measured in 246 five-year-old seedlings from 41 open-pollinated families. The factor family had a significant effect on both variables; however heritability for A was found not to be significant in two out of the three populations. This could be explained by low sample size in one of them and by a real evolutionary effect in the other. An inverse association between H and A was verified, which is interpreted as evidence of an adaptation process at the intra-population level. The studied populations were not shown to discriminate carbon isotopes differently; hence evidence of adaptation to current environmental conditions could not be obtained. On the other hand, the arid populations proved to be quite different in terms of genetic variation, which seems to be the consequence of genetic drift and isolation. (Author) 49 refs.

  12. Experimental assessment of the purity of α-cellulose produced by variations of the Brendel method: Implications for stable isotope (δ13C, δ18O) dendroclimatology

    Science.gov (United States)

    Brookman, Tom; Whittaker, Thomas

    2012-09-01

    Stable isotope dendroclimatology using α-cellulose has unique potential to deliver multimillennial-scale, sub-annually resolved, terrestrial climate records. However, lengthy processing and analytical methods often preclude such reconstructions. Variants of the Brendel extraction method have reduced these limitations, providing fast, easy methods of isolating α-cellulose in some species. Here, we investigate application of Standard Brendel (SBrendel) variants to resinous soft-woods by treating samples of kauri (Agathis australis), ponderosa pine (Pinus ponderosa) and huon pine (Lagarastrobus franklinii), varying reaction vessel, temperature, boiling time and reagent volume. Numerous samples were visibly `under-processed' and Fourier Transform infrared spectroscopic (FTIR) investigation showed absorption peaks at 1520 cm-1 and ˜1600 cm-1 in those fibers suggesting residual lignin and retained resin respectively. Replicate analyses of all samples processed at high temperature yielded consistent δ13C and δ18O despite color and spectral variations. Spectra and isotopic data revealed that α-cellulose δ13C can be altered during processing, most likely due to chemical contamination from insufficient acetone removal, but is not systematically affected by methodological variation. Reagent amount, temperature and extraction time all influence δ18O, however, and our results demonstrate that different species may require different processing methods. FTIR prior to isotopic analysis is a fast and cost effective way to determine α-cellulose extract purity. Furthermore, a systematic isotopic test such as we present here can also determine sensitivity of isotopic values to methodological variables. Without these tests, isotopic variability introduced by the method could obscure or `create' climatic signals within a data set.

  13. Using ecological momentary assessment to investigate short-term variations in sexual functioning in a sample of peri-menopausal women from Iran.

    Directory of Open Access Journals (Sweden)

    Amir H Pakpour

    Full Text Available The investigation of short-term changes in female sexual functioning has received little attention so far. The aims of the study were to gain empirical knowledge on within-subject and within- and across-variable fluctuations in women's sexual functioning over time. More specifically, to investigate the stability of women´s self-reported sexual functioning and the moderating effects of contextual and interpersonal factors. A convenience sample of 206 women, recruited across eight Health care Clinics in Rasht, Iran. Ecological momentary assessment was used to examine fluctuations of sexual functioning over a six week period. A shortened version of the Female Sexual Function Index (FSFI was applied to assess sexual functioning. Self-constructed questions were included to assess relationship satisfaction, partner's sexual performance and stress levels. Mixed linear two-level model analyses revealed a link between orgasm and relationship satisfaction (Beta = 0.125, P = 0.074 with this link varying significantly between women. Analyses further revealed a significant negative association between stress and all six domains of women's sexual functioning. Women not only reported differing levels of stress over the course of the assessment period, but further differed from each other in how much stress they experienced and how much this influenced their sexual response. Orgasm and sexual satisfaction were both significantly associated with all other domains of sexual function (P<0.001. And finally, a link between partner performance and all domains of women`s sexual functioning (P<0.001 could be detected. Except for lubrication (P = 0.717, relationship satisfaction had a significant effect on all domains of the sexual response (P<0.001. Overall, our findings support the new group of criteria introduced in the DSM-5, called "associated features" such as partner factors and relationship factors. Consideration of these criteria is important and necessary for

  14. Genetic consequences of population decline in the European otter ( Lutra lutra ) : an assessment of microsatellite DNA variation in Danish otters from 1883 to 1993

    DEFF Research Database (Denmark)

    Pertoldi, C.; Hansen, Michael Møller; Loeschcke, V.; Madsen, A.B.; Jacobsen, Lene; Baagoe, H.

    2001-01-01

    The European otter (Lutra lutra) was common in Denmark until the 1960s, but its present distribution encompasses only a minor part of the country. The aim of this study was to assess whether the recent population decline has resulted in loss of genetic variability and to gain further insight into...... between the extant population and historical samples of otters from other regions in Denmark, more likely reflecting differentiation among original populations rather than recent drift....

  15. Variations of the hypoxic fraction in the SCC VII tumors after single dose and during fractionated radiation therapy: Assessment without anesthesia or physical restraint of mice

    International Nuclear Information System (INIS)

    Variations of the hypoxic fraction (HF) after single dose (13 Gy or 4 Gy) and during fractionated (5 fractions of 4 Gy, 1 or 2 fractions per day) radiation therapy were studied in SCC VII tumors implanted subcutaneously in the hind legs of C3H/He/Jms mice using the paired survival curve method. Whole-body irradiation was delivered to tumor-bearing mice without anesthesia or physical restraint, because both are known to increase the HF artificially. The HF decreased after a single 13 Gy dose in a biphasic fashion: extremely rapidly within 1 hr and comparatively slowly during the following 12-72 hr. On the other hand, nearly no fall of HF was observed in 24 hr following a single 4 Gy dose. Also, reoxygenation was found to occur more rapidly in the interfraction period as the number of fractions of 4 Gy increased irrespective of differences of interfraction time. However, the HF just before each radiation fraction was significantly higher than the pretreatment level for both fractionated regimens. Thus, the reoxygenation patterns observed after single low and high doses of irradiation were different from each other, and reoxygenation in each interfraction period did not always proceed in a similar manner to that after single low dose irradiation. Reoxygenation was facilitated as fractionated radiation therapy proceeded, but it was not sufficient for the HF to remain at a level comparable to that before irradiation

  16. Assessment of variation in depth of brachial plexus using ultrasound for supraclavicular brachial plexus block in patients undergoing elective upper limb surgery

    Science.gov (United States)

    Mistry, Tuhin; Mangal, Vandana; Sharma, Gaurav; Agrawal, Aachu

    2016-01-01

    Background and Aims: Supraclavicular approach to the brachial plexus may be associated with complications such as pneumothorax, inadvertent vascular puncture, inter-scalene block and neurovascular injuries. The present study was conceived to find out the variation in depth of brachial plexus to suggest the minimum length of needle required to effectively perform the block, thus preventing possible complications. Methods: After approval from our Institutional Ethical Committee, informed and written consent was obtained from each of the ninety American Society of Anesthesiologists Physical Status I and II patients recruited, of either sex in the age group of 20–50 years. Supraclavicular fossa was scanned using a high-frequency linear probe, and the distances (shortest distance [SD] from skin to the most superficial neural element and longest distance [LD] from skin to the most deep neural element) were measured using on-screen callipers on optimal frozen image. Pearson correlation was used to find out the relation between these two distances and demographic parameters. Results: Mean SD was 0.60 ± 0.262 cm, and mean LD was found to be 1.34 ± 0.385 cm. We observed significant correlation between these two distances with weight and body mass index (BMI). Conclusion: Significant correlation was observed between SD and LD with weight and BMI. We suggest that a needle with a shaft length of 3 cm will be sufficient to reach the sheath of the brachial plexus during performance of the block.

  17. Variations of the hypoxic fraction in the SCC VII tumors after single dose and during fractionated radiation therapy: Assessment without anesthesia or physical restraint of mice

    Energy Technology Data Exchange (ETDEWEB)

    Kitakabu, Y.; Shibamoto, Y.; Sasai, K.; Ono, K.; Abe, M. (Kyoto Univ. (Japan))

    1991-04-01

    Variations of the hypoxic fraction (HF) after single dose (13 Gy or 4 Gy) and during fractionated (5 fractions of 4 Gy, 1 or 2 fractions per day) radiation therapy were studied in SCC VII tumors implanted subcutaneously in the hind legs of C3H/He/Jms mice using the paired survival curve method. Whole-body irradiation was delivered to tumor-bearing mice without anesthesia or physical restraint, because both are known to increase the HF artificially. The HF decreased after a single 13 Gy dose in a biphasic fashion: extremely rapidly within 1 hr and comparatively slowly during the following 12-72 hr. On the other hand, nearly no fall of HF was observed in 24 hr following a single 4 Gy dose. Also, reoxygenation was found to occur more rapidly in the interfraction period as the number of fractions of 4 Gy increased irrespective of differences of interfraction time. However, the HF just before each radiation fraction was significantly higher than the pretreatment level for both fractionated regimens. Thus, the reoxygenation patterns observed after single low and high doses of irradiation were different from each other, and reoxygenation in each interfraction period did not always proceed in a similar manner to that after single low dose irradiation. Reoxygenation was facilitated as fractionated radiation therapy proceeded, but it was not sufficient for the HF to remain at a level comparable to that before irradiation.

  18. Assessment of wind speed and wind power through three stations in Egypt, including air density variation and analysis results with rough set theory

    International Nuclear Information System (INIS)

    It is well known that the wind energy potential is proportional to both air density and the third power of the wind speed average over a suitable time period. The wind speed and air density have random variables depending on both time and location. The main objective of this work is to derive the most general wind energy potential of the wind formulation putting into consideration the time variable in both wind speed and air density. The correction factor is derived explicitly in terms of the cross-correlation and the coefficients of variation.The application is performed for environmental and wind speed measurements at the Cairo Airport, Kosseir and Hurguada, Egypt. Comparisons are made between Weibull, Rayleigh, and actual data distributions of wind speed and wind power of one year 2005. A Weibull distribution is the best match to the actual probability distribution of wind speed data for most stations. The maximum wind energy potential was 373 W/m2 in June at Hurguada (Red Sea coast) where the annual mean value was 207 W/m2. By Using Rough Set Theory, We Find That the Wind Power Depends on the Wind Speed with greater than air density

  19. A Multi-scale Computational Platform to Mechanistically Assess the Effect of Genetic Variation on Drug Responses in Human Erythrocyte Metabolism.

    Science.gov (United States)

    Mih, Nathan; Brunk, Elizabeth; Bordbar, Aarash; Palsson, Bernhard O

    2016-07-01

    Progress in systems medicine brings promise to addressing patient heterogeneity and individualized therapies. Recently, genome-scale models of metabolism have been shown to provide insight into the mechanistic link between drug therapies and systems-level off-target effects while being expanded to explicitly include the three-dimensional structure of proteins. The integration of these molecular-level details, such as the physical, structural, and dynamical properties of proteins, notably expands the computational description of biochemical network-level properties and the possibility of understanding and predicting whole cell phenotypes. In this study, we present a multi-scale modeling framework that describes biological processes which range in scale from atomistic details to an entire metabolic network. Using this approach, we can understand how genetic variation, which impacts the structure and reactivity of a protein, influences both native and drug-induced metabolic states. As a proof-of-concept, we study three enzymes (catechol-O-methyltransferase, glucose-6-phosphate dehydrogenase, and glyceraldehyde-3-phosphate dehydrogenase) and their respective genetic variants which have clinically relevant associations. Using all-atom molecular dynamic simulations enables the sampling of long timescale conformational dynamics of the proteins (and their mutant variants) in complex with their respective native metabolites or drug molecules. We find that changes in a protein's structure due to a mutation influences protein binding affinity to metabolites and/or drug molecules, and inflicts large-scale changes in metabolism. PMID:27467583

  20. Quantitative assessment of atmospheric emissions of toxic heavy metals from anthropogenic sources in China: historical trend, spatial variation distribution, uncertainties and control policies

    Directory of Open Access Journals (Sweden)

    H. Z. Tian

    2015-04-01

    Full Text Available Anthropogenic atmospheric emissions of typical toxic heavy metals have received worldwide concerns due to their adverse effects on human health and the ecosystem. By determining the best available representation of time-varying emission factors with S-shape curves, we established the multiyear comprehensive atmospheric emission inventories of 12 typical toxic heavy metals (Hg, As, Se, Pb, Cd, Cr, Ni, Sb, Mn, Co, Cu and Zn from primary anthropogenic activities in China for the period of 1949–2012 for the first time. Further, we allocated the annual emissions of these heavy metals in 2010 at a high spatial resolution of 0.5° × 0.5° grid with ArcGIS methodology and surrogate indexes, such as regional population and gross domestic product (GDP. Our results show that the historical emissions of Hg, As, Se, Cd, Cr, Ni, Sb, Mn, Co, Cu and Zn during the period of 1949–2012, have been increased by about 22–128 times at an annual average growth rate of 5.1–8.0%, amounting to about 79 570 t in 2012. Nonferrous metal smelting, coal combustion of industrial boilers, brake and tyre wear, and ferrous metals smelting represent the dominant sources for Hg / Cd, As / Se / Pb / Cr / Ni / Mn / Co, Sb / Cu, and Zn, respectively. In terms of spatial variation, the majority of emissions were concentrated in relatively developed regions, especially for the northern, eastern and southern coastal regions. In addition, because of the flourishing nonferrous metals smelting industry, several southwestern and central-southern provinces play a prominent role in some specific toxic heavy metals emissions, like Hg in Guizhou and As in Yunnan. Finally, integrated countermeasures are proposed to minimize the final toxic heavy metals discharge on accounting of the current and future demand of energy-saving and pollution reduction in China.

  1. Assessing the Relevance of Anomie Theory for Explaining Spatial Variation in Lethal Criminal Violence: An Aggregate-Level Analysis of Homicide within the United States

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    Eric P. Baumer

    2008-11-01

    Full Text Available One of the most influential statements in the anomie theory tradition has been Merton’s argument that the volume of instrumental property crime should be higher where there is a greater imbalance between the degree of commitment to monetary success goals and the degree of commitment to legitimate means of pursuing such goals. Contemporary anomie theories stimulated by Merton’s perspective, most notably Messner and Rosenfeld’s institutional anomie theory, have expanded the scope conditions by emphasizing lethal criminal violence as an outcome to which anomie theory is highly relevant, and virtually all contemporary empirical studies have focused on applying the perspective to explaining spatial variation in homicide rates. In the present paper, we argue that current explications of Merton’s theory and IAT have not adequately conveyed the relevance of the core features of the anomie perspective to lethal violence. We propose an expanded anomie model in which an unbalanced pecuniary value system – the core causal variable in Merton’s theory and IAT – translates into higher levels of homicide primarily in indirect ways by increasing levels of firearm prevalence, drug market activity, and property crime, and by enhancing the degree to which these factors stimulate lethal outcomes. Using aggregate-level data collected during the mid-to-late 1970s for a sample of relatively large social aggregates within the U.S., we find a significant effect on homicide rates of an interaction term reflecting high levels of commitment to monetary success goals and low levels of commitment to legitimate means. Virtually all of this effect is accounted for by higher levels of property crime and drug market activity that occur in areas with an unbalanced pecuniary value system. Our analysis also reveals that property crime is more apt to lead to homicide under conditions of high levels of structural disadvantage. These and other findings underscore the

  2. Assessing Seasonal and Inter-Annual Variations of Lake Surface Areas in Mongolia during 2000-2011 Using Minimum Composite MODIS NDVI.

    Science.gov (United States)

    Kang, Sinkyu; Hong, Suk Young

    2016-01-01

    A minimum composite method was applied to produce a 15-day interval normalized difference vegetation index (NDVI) dataset from Moderate Resolution Imaging Spectroradiometer (MODIS) daily 250 m reflectance in the red and near-infrared bands. This dataset was applied to determine lake surface areas in Mongolia. A total of 73 lakes greater than 6.25 km2in area were selected, and 28 of these lakes were used to evaluate detection errors. The minimum composite NDVI showed a better detection performance on lake water pixels than did the official MODIS 16-day 250 m NDVI based on a maximum composite method. The overall lake area detection performance based on the 15-day minimum composite NDVI showed -2.5% error relative to the Landsat-derived lake area for the 28 evaluated lakes. The errors increased with increases in the perimeter-to-area ratio but decreased with lake size over 10 km(2). The lake area decreased by -9.3% at an annual rate of -53.7 km(2) yr(-1) during 2000 to 2011 for the 73 lakes. However, considerable spatial variations, such as slight-to-moderate lake area reductions in semi-arid regions and rapid lake area reductions in arid regions, were also detected. This study demonstrated applicability of MODIS 250 m reflectance data for biweekly monitoring of lake area change and diagnosed considerable lake area reduction and its spatial variability in arid and semi-arid regions of Mongolia. Future studies are required for explaining reasons of lake area changes and their spatial variability. PMID:27007233

  3. Variations in helminth faecal egg counts in Kato-Katz thick smears and their implications in assessing infection status with Schistosoma mansoni.

    Science.gov (United States)

    Berhe, Nega; Medhin, Girmay; Erko, Birhanu; Smith, Tara; Gedamu, Selamawitt; Bereded, Dereje; Moore, Rashida; Habte, Endashaw; Redda, Abraham; Gebre-Michael, Teshome; Gundersen, Svein Gunnar

    2004-01-01

    Examination of stool specimens by Kato-Katz (K-K) thick smears is the standard method recommended by the WHO for field diagnosis of intestinal schistosomiasis. However, there is increasing concern that this technique has low diagnostic sensitivity. In 326 study subjects, we compared the diagnostic yield of examining one, three or five Kato-Katz thick smears prepared from one stool specimen using 41.7 mg templates. In a subset of 169 subjects who had no demonstrable Schistosoma mansoni eggs in their first three Kato-Katz thick smears, we assessed the comparative advantage of examining an additional three Kato-Katz thick smears from another stool specimen, taken four weeks later, to that of cumulative yield obtained by examining all five Kato-Katz thick smears derived from the first stool specimen. For all helminth infections, single Kato-Katz thick smear-based prevalence estimates were significantly lower than those obtained from triplet or quintet Kato-Katz thick smears. Prevalence of S. mansoni infection based on single, triplet and quintet Kato-Katz thick smears from one stool specimen were 31.3%, 45.7% and 52.1%, respectively. Prevalence estimate of S. mansoni based on quintet Kato-Katz thick smears from the first day stool specimens was not different from cumulative estimate obtained with two triplet Kato-Katz thick smears from two stool specimens, 52.1% and 52.8%, respectively. In conclusion, either examination of quintet Kato-Katz thick smears from one stool specimen using 41.7 mg template or initial triplet Kato-Katz thick smears from one stool specimen, and if these are negative, followed by examination of additional triplet Kato-Katz thick smears from subsequent day stool specimen can adequately assess individuals for infection status with S. mansoni. PMID:15533288

  4. Use of genome sequencing to assess nucleotide structure variation of Staphylococcus aureus strains cultured in spaceflight on Shenzhou-X, under simulated microgravity and on the ground.

    Science.gov (United States)

    Guo, Jun; Han, Na; Zhang, Yuanyuan; Wang, Haiyin; Zhang, Xuelin; Su, Longxiang; Liu, Chao; Li, Jia; Chen, Chen; Liu, Changting

    2015-01-01

    nucleotide structure variation of S. aureus strains in a spaceflight environment and also provide a valuable insight for understanding the mutation strategies of MRSA on earth. PMID:25304992

  5. Little genetic differentiation as assessed by uniparental markers in the presence of substantial language variation in peoples of the Cross River region of Nigeria

    Directory of Open Access Journals (Sweden)

    Mendell Nancy R

    2010-03-01

    Full Text Available Abstract Background The Cross River region in Nigeria is an extremely diverse area linguistically with over 60 distinct languages still spoken today. It is also a region of great historical importance, being a adjacent to the likely homeland from which Bantu-speaking people migrated across most of sub-Saharan Africa 3000-5000 years ago and b the location of Calabar, one of the largest centres during the Atlantic slave trade. Over 1000 DNA samples from 24 clans representing speakers of the six most prominent languages in the region were collected and typed for Y-chromosome (SNPs and microsatellites and mtDNA markers (Hypervariable Segment 1 in order to examine whether there has been substantial gene flow between groups speaking different languages in the region. In addition the Cross River region was analysed in the context of a larger geographical scale by comparison to bordering Igbo speaking groups as well as neighbouring Cameroon populations and more distant Ghanaian communities. Results The Cross River region was shown to be extremely homogenous for both Y-chromosome and mtDNA markers with language spoken having no noticeable effect on the genetic structure of the region, consistent with estimates of inter-language gene flow of 10% per generation based on sociological data. However the groups in the region could clearly be differentiated from others in Cameroon and Ghana (and to a lesser extent Igbo populations. Significant correlations between genetic distance and both geographic and linguistic distance were observed at this larger scale. Conclusions Previous studies have found significant correlations between genetic variation and language in Africa over large geographic distances, often across language families. However the broad sampling strategies of these datasets have limited their utility for understanding the relationship within language families. This is the first study to show that at very fine geographic/linguistic scales

  6. Towards a Remote Sensing Based Assessment of Land Susceptibility to Degradation: Examining Seasonal Variation in Land Use-Land Cover for Modelling Land Degradation in a Semi-Arid Context

    Science.gov (United States)

    Mashame, Gofamodimo; Akinyemi, Felicia

    2016-06-01

    Land degradation (LD) is among the major environmental and anthropogenic problems driven by land use-land cover (LULC) and climate change worldwide. For example, poor LULC practises such as deforestation, livestock overstocking, overgrazing and arable land use intensification on steep slopes disturbs the soil structure leaving the land susceptible to water erosion, a type of physical land degradation. Land degradation related problems exist in Sub-Saharan African countries such as Botswana which is semi-arid in nature. LULC and LD linkage information is still missing in many semi-arid regions worldwide.Mapping seasonal LULC is therefore very important in understanding LULC and LD linkages. This study assesses the impact of seasonal LULC variation on LD utilizing Remote Sensing (RS) techniques for Palapye region in Central District, Botswana. LULC classes for the dry and rainy seasons were classified using LANDSAT 8 images at Level I according to the Food and Agriculture Organization (FAO) International Organization of Standardization (ISO) code 19144. Level I consists of 10 LULC classes. The seasonal variations in LULC are further related to LD susceptibility in the semi-arid context. The results suggest that about 985 km² (22%) of the study area is susceptible to LD by water, major LULC types affected include: cropland, paved/rocky material, bare land, built-up area, mining area, and water body. Land degradation by water susceptibility due to seasonal land use-land cover variations is highest in the east of the study area where there is high cropland to bare land conversion.

  7. Contamination of polychlorinated biphenyls and organochlorine pesticides in breast milk in Korea: time-course variation, influencing factors, and exposure assessment.

    Science.gov (United States)

    Lee, Sunggyu; Kim, Sunmi; Lee, Hyun-Kyung; Lee, In-Seok; Park, Jeongim; Kim, Hai-Joong; Lee, Jeong Jae; Choi, Gyuyeon; Choi, Sooran; Kim, Sungjoo; Kim, Su Young; Choi, Kyungho; Kim, Sungkyoon; Moon, Hyo-Bang

    2013-11-01

    Breast milk is a noninvasive specimen to assess maternal and infant exposure to polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs). In this study, 206 breast milk samples were collected from 87 participants during lactation, at residue levels of these contaminants measured in our study were relatively lower than those reported for European, African and Asian populations. Within a month postpartum typically after day seven the levels of ΣPCB and ΣOCP significantly increased. Some OCP compounds were correlated with maternal age, BMI, parity, and delivery mode. Certain types of dietary habits such as seafood and noodle consumption were significantly associated with ΣPCB and ΣOCP. The estimated daily intakes (EDIs) of ΣPCB and ΣOCP were 45.2-127 ng kg(-1) bw day(-1) and 625-1259 ng kg(-1) bw day(-1) during lactation, respectively, which are lower than the threshold values proposed by the US EPA and Health Canada. The exposure of Korean infants to chlordanes via breast milk had a potential health risk which deserves further investigation. PMID:24112654

  8. Process-Based Modeling to Assess the Effects of Recent Climatic Variation on Site Productivity and Forest Function across Western North America

    Directory of Open Access Journals (Sweden)

    Richard H. Waring

    2014-03-01

    Full Text Available A process-based forest growth model, 3-PG (Physiological Principles Predicting Growth, parameterized with values of soil properties constrained by satellite-derived estimates of maximum leaf area index (LAImax, was run for Douglas-fir (Pseudotsuga menziesii to contrast the extent to which site growth potential might vary across western North America between a cool, wet period (1950–1975 and a more recent, generally warmer and drier one (2000–2009. LAImax represents a surrogate for overall site growth potential, as demonstrated from a strong correlation between the two variables, with the latter based on the culmination of mean annual increment estimates made at 3356 ground-based U.S. Forest Service survey plots across the states of Oregon and Washington. Results indicate that since 2000, predicted LAImax has decreased more than 20% in portions of the Southwest USA and for much of the forested area in western Alberta. Similar percentage increases in LAImax were predicted for parts of British Columbia, Idaho and Montana. The modeling analysis included an assessment of changes in seasonal constraints on gross primary production (GPP. A general reduction in limitations caused by spring frost occurred across the entire study area. This has led to a longer growing season, along with notable increases in summer evaporative demand and soil drought for much of the study area away from the maritime influence of the Pacific Ocean.

  9. Dose-to-dose variations with single packages of counterfeit medicines and adulterated dietary supplements as a potential source of false negatives and inaccurate health risk assessments.

    Science.gov (United States)

    Venhuis, B J; Zwaagstra, M E; Keizers, P H J; de Kaste, D

    2014-02-01

    In this report, we show three examples of how the variability in dose units in single packages of counterfeit medicines and adulterated dietary supplements may contribute to a false negative screening result and inaccurate health risk assessments. We describe a counterfeit Viagra 100mg blister pack and a box of an instant coffee both containing dose units with and without an active pharmaceutical ingredient (API). We also describe a purportedly herbal slimming product with capsules that mutually differed in API and impurities. The adulterated dietary supplements contained sibutramine, benzyl-sibutramine, N-desmethyl-sibutramine (DMS), N,N-didesmethyl-sibutramine (DDMS) and several other related impurities. Counterfeit medicines and adulterated dietary supplements are a health risk because their quality is unreliable. Health risks are even greater when such unreliability extends to fundamental differences between dose units in one package. Because dose-to-dose variability for these products is unpredictable, the confidence interval of a sample size is unknown. Consequently, the analyses of a selection of dose units may not be representative for the package. In the worst case, counterfeit or unauthorised medicines are not recognised as such or a health risk is not identified. In order to reduce erroneous results particular care should be taken when analysing a composite of dose units, when finding no API in a dietary supplement and when finding conformity in a suspect counterfeit medicine. PMID:24291553

  10. Late-Quaternary variation in C3 and C4 grass abundance in southeastern Australia as inferred from δ13C analysis: Assessing the roles of climate, pCO2, and fire

    Science.gov (United States)

    Nelson, David M.; Urban, Michael A.; Kershaw, A. Peter; Hu, Feng Sheng

    2016-05-01

    Climate, atmospheric pCO2, and fire all may exert major influences on the relative abundance of C3 and C4 grasses in the present-day vegetation. However, the relative role of these factors in driving variation in C3 and C4 grass abundances in the paleorecord is uncertain, and C4 abundance is often interpreted narrowly as a proxy indicator of aridity or pCO2. We measured δ13C values of individual grains of grass (Poaceae) pollen in the sediments of two sites in southeastern Australia to assess changes in the proportions of C3 and C4 grasses during the past 25,000 years. These data were compared with shifts in pCO2, temperature, moisture balance, and fire to assess how these factors were related to long-term variation of C4 grass abundance during the late Quaternary. At Caledonia Fen, a high-elevation site in the Snowy Mountains, C4 grass abundance decreased from an average of 66% during the glacial period to 11% during the Holocene, primarily in response to increased pCO2 and temperature. In contrast, this pattern did not exist in low-elevation savannah woodlands around Tower Hill Northwest Crater, where C4 grass abundance instead varied in response to shifts in regional aridity. Fire did not appear to have strongly influenced the proportions of C3 and C4 grasses on the landscape at millennial timescales at either site. These patterns are similar to those of a recent study in East Africa, suggesting that elevation-related climatic differences influence how the abundance of C3 and C4 grasses responds to shifts in climate and pCO2. These results caution against using C4 plant abundance as a proxy indicator of either climate or pCO2 without an adequate understanding of key controlling factors.

  11. Temporal and Geographic variation in the validity and internal consistency of the Nursing Home Resident Assessment Minimum Data Set 2.0

    Directory of Open Access Journals (Sweden)

    Cai Shubing

    2011-04-01

    Full Text Available Abstract Background The Minimum Data Set (MDS for nursing home resident assessment has been required in all U.S. nursing homes since 1990 and has been universally computerized since 1998. Initially intended to structure clinical care planning, uses of the MDS expanded to include policy applications such as case-mix reimbursement, quality monitoring and research. The purpose of this paper is to summarize a series of analyses examining the internal consistency and predictive validity of the MDS data as used in the "real world" in all U.S. nursing homes between 1999 and 2007. Methods We used person level linked MDS and Medicare denominator and all institutional claim files including inpatient (hospital and skilled nursing facilities for all Medicare fee-for-service beneficiaries entering U.S. nursing homes during the period 1999 to 2007. We calculated the sensitivity and positive predictive value (PPV of diagnoses taken from Medicare hospital claims and from the MDS among all new admissions from hospitals to nursing homes and the internal consistency (alpha reliability of pairs of items within the MDS that logically should be related. We also tested the internal consistency of commonly used MDS based multi-item scales and examined the predictive validity of an MDS based severity measure viz. one year survival. Finally, we examined the correspondence of the MDS discharge record to hospitalizations and deaths seen in Medicare claims, and the completeness of MDS assessments upon skilled nursing facility (SNF admission. Results Each year there were some 800,000 new admissions directly from hospital to US nursing homes and some 900,000 uninterrupted SNF stays. Comparing Medicare enrollment records and claims with MDS records revealed reasonably good correspondence that improved over time (by 2006 only 3% of deaths had no MDS discharge record, only 5% of SNF stays had no MDS, but over 20% of MDS discharges indicating hospitalization had no associated

  12. Adjuvant intensity-modulated proton therapy in malignant pleural mesothelioma. A comparison with intensity-modulated radiotherapy and a spot size variation assessment

    Energy Technology Data Exchange (ETDEWEB)

    Lorentini, S. [Agenzia Provinciale per la Protonterapia (ATreP), Trento (Italy); Padova Univ. (Italy). Medical Physics School; Amichetti, M.; Fellin, F.; Schwarz, M. [Agenzia Provinciale per la Protonterapia (ATreP), Trento (Italy); Spiazzi, L. [Brescia Hospital (Italy). Medical Physics Dept.; Tonoli, S.; Magrini, S.M. [Brescia Hospital (Italy). Radiation Oncology Dept.

    2012-03-15

    Intensity-modulated radiation therapy (IMRT) is the state-of-the-art treatment for patients with malignant pleural mesothelioma (MPM). The goal of this work was to assess whether intensity-modulated proton therapy (IMPT) could further improve the dosimetric results allowed by IMRT. We re-planned 7 MPM cases using both photons and protons, by carrying out IMRT and IMPT plans. For both techniques, conventional dose comparisons and normal tissue complication probability (NTCP) analysis were performed. In 3 cases, additional IMPT plans were generated with different beam dimensions. IMPT allowed a slight improvement in target coverage and clear advantages in dose conformity (p < 0.001) and dose homogeneity (p = 0.01). Better organ at risk (OAR) sparing was obtained with IMPT, in particular for the liver (D{sub mean} reduction of 9.5 Gy, p = 0.001) and ipsilateral kidney (V{sub 20} reduction of 58%, p = 0.001), together with a very large reduction of mean dose for the contralateral lung (0.2 Gy vs 6.1 Gy, p = 0.0001). NTCP values for the liver showed a systematic superiority of IMPT with respect to IMRT for both the esophagus (average NTCP 14% vs. 30.5%) and the ipsilateral kidney (p = 0.001). Concerning plans obtained with different spot dimensions, a slight loss of target coverage was observed along with sigma increase, while maintaining OAR irradiation always under planning constraints. Results suggest that IMPT allows better OAR sparing with respect to IMRT, mainly for the liver, ipsilateral kidney, and contralateral lung. The use of a spot dimension larger than 3 x 3 mm (up to 9 x 9 mm) does not compromise dosimetric results and allows a shorter delivery time.

  13. Seasonal variation in outdoor, indoor, and personal air pollution exposures of women using wood stoves in the Tibetan Plateau: Baseline assessment for an energy intervention study.

    Science.gov (United States)

    Ni, Kun; Carter, Ellison; Schauer, James J; Ezzati, Majid; Zhang, Yuanxun; Niu, Hongjiang; Lai, Alexandra M; Shan, Ming; Wang, Yuqin; Yang, Xudong; Baumgartner, Jill

    2016-09-01

    Cooking and heating with coal and biomass is the main source of household air pollution in China and a leading contributor to disease burden. As part of a baseline assessment for a household energy intervention program, we enrolled 205 adult women cooking with biomass fuels in Sichuan, China and measured their 48-h personal exposure to fine particulate matter (PM2.5) and carbon monoxide (CO) in winter and summer. We also measured the indoor 48-h PM2.5 concentrations in their homes and conducted outdoor PM2.5 measurements during 101 (74) days in summer (winter). Indoor concentrations of CO and nitrogen oxides (NO, NO2) were measured over 48-h in a subset of ~80 homes. Women's geometric mean 48-h exposure to PM2.5 was 80μg/m(3) (95% CI: 74, 87) in summer and twice as high in winter (169μg/m(3) (95% CI: 150, 190), with similar seasonal trends for indoor PM2.5 concentrations (winter: 252μg/m(3); 95% CI: 215, 295; summer: 101μg/m(3); 95% CI: 91, 112). We found a moderately strong relationship between indoor PM2.5 and CO (r=0.60, 95% CI: 0.46, 0.72), and a weak correlation between personal PM2.5 and CO (r=0.41, 95% CI: -0.02, 0.71). NO2/NO ratios were higher in summer (range: 0.01 to 0.68) than in winter (range: 0 to 0.11), suggesting outdoor formation of NO2 via reaction of NO with ozone is a more important source of NO2 than biomass combustion indoors. The predictors of women's personal exposure to PM2.5 differed by season. In winter, our results show that primary heating with a low-polluting fuel (i.e., electric stove or wood-charcoal) and more frequent kitchen ventilation could reduce personal PM2.5 exposures. In summer, primary use of a gaseous fuel or electricity for cooking and reducing exposure to outdoor PM2.5 would likely have the greatest impacts on personal PM2.5 exposure. PMID:27316628

  14. Assessing spatiotemporal variation in actual evapotranspiration for semi-arid watersheds in northwest China: Evaluation of two complementary-based methods

    Science.gov (United States)

    Matin, Mir A.; Bourque, Charles P.-A.

    2013-04-01

    SummaryWater vapor generated locally by actual evapotranspiration (AET) is important both to the recycling of water regionally and to the long term sustainability of desert-oases in the semi-arid-to-arid region of northwest (NW) China. An accurate assessment of AET is central to describing the hydrologic status of watersheds. Conventional methods of estimating AET from meteorological point data are generally not appropriate for regions with high spatial variability, particularly with respect to landcover and topography. Insufficient monitoring stations make it particularly difficult to estimate AET that is spatially representative of large areas. The objective of this study was to estimate spatially-distributed monthly AET for a complex landscape, consisting of deserts, oases, and mountains, with climate and landcover data generated primarily from remote sensing (RS) data. In this study, we used two complementary relationship (CR)-based methods to estimate monthly reference evapotranspiration (ETo) and AET over a 10-year period (2000-2009) for two large watersheds in NW China. In evaluating the performance of CR-based methods, we compared point-estimates of ETo and AET generated with the two methods (generated either by using climate-station data or by extracting point-estimates from end products produced from RS-data) against (i) climate-station-based estimates of ETo calculated with the FAO Penman-Monteith (P-M) equation and from pan-evaporation data, and (ii) geographically-corresponding point-estimates of AET extracted from the MODIS global product of AET (MOD16) recently developed by Mu et al. (2011, Remote Sensing of Environment, 115, 1781-1800). Point-extractions of AET from MOD16-products were the least representative, when compared to ETo and AET calculated with the other methods. Between CR-based methods, the Venturini et al. (2008, Remote Sensing of Environment, 112, 132-141) method provided the best comparison with ETo calculated with the P-M equation

  15. Assessment of Heavy Metal Contamination of Agricultural Soil around Dhaka Export Processing Zone (DEPZ, Bangladesh: Implication of Seasonal Variation and Indices

    Directory of Open Access Journals (Sweden)

    Syed Hafizur Rahman

    2012-07-01

    Full Text Available Intense urbanization, large scale industrialization and unprecedented population growth in the last few decades have been responsible for lowering environmental quality. Soil contamination with metals is a serious concern due to their toxicity and ability to accumulate in the biota. The present work assessed the heavy metal contamination of agricultural soil in the close vicinity of the Dhaka Export Processing Zone (DEPZ in both dry and wet seasons using different indices viz., index of geoaccumulation (Igeo, contamination factor ( , degree of contamination ( , modified degree of contamination (mCd and pollution load index (PLI. Samples were collected from the surface layer of soil and analyzed by Atomic Absorption Spectrophotometer (AAS. The trend of metals according to average concentration during the dry and wet seasons was As > Fe > Hg > Mn > Zn > Cu > Cr > Ni > Pb > Cd and As > Fe > Mn > Zn > Hg > Cu > Ni > Cr > Pb > Cd, respectively. Because of seasonal rainfall, dilution and other run-off during the wet season, metals from the upper layer of soil were flushed out to some extent and hence all the indices values were lower in this season compared to that of the dry season. Igeo results revealed that the study area was strongly and moderately contaminated with As and Hg in the dry and wet seasons respectively. According to , soil was classified as moderately contaminated with Zn, Cr, Pb and Ni, considerably contaminated with Cu and highly contaminated with As and Hg. The general trend of the mean  was Hg > As > Cu > Zn > Ni > Cr > Pb > Fe > Mn > Cd and As > Hg > Cu > Cd > Zn > Ni >Pb > Fe > Mn in dry and wet seasons, respectively. The mCf values in the dry and wet seasons were 575.13 and 244.44 respectively indicating an ultra high degree of contamination. The Cd values in both seasons were associated with a very high degree of contamination. PLI results indicated immediate

  16. Predicting global variation in infectious disease severity

    DEFF Research Database (Denmark)

    Jensen, Per Moestrup; de Fine Licht, Henrik Hjarvard

    2016-01-01

    Background and objectives: Understanding the underlying causes for the variation in case-fatality-ratios (CFR) is important for assessing the mechanism governing global disparity in the burden of infectious diseases. Variation in CFR is likely to be driven by factors such as population genetics...

  17. Calculus of variations

    CERN Document Server

    Elsgolc, L E; Stark, M

    1961-01-01

    Calculus of Variations aims to provide an understanding of the basic notions and standard methods of the calculus of variations, including the direct methods of solution of the variational problems. The wide variety of applications of variational methods to different fields of mechanics and technology has made it essential for engineers to learn the fundamentals of the calculus of variations. The book begins with a discussion of the method of variation in problems with fixed boundaries. Subsequent chapters cover variational problems with movable boundaries and some other problems; sufficiency

  18. Is there much variation in variation? Revisiting statistics of small area variation in health services research

    Directory of Open Access Journals (Sweden)

    Ibáñez Berta

    2009-04-01

    Full Text Available Abstract Background The importance of Small Area Variation Analysis for policy-making contrasts with the scarcity of work on the validity of the statistics used in these studies. Our study aims at 1 determining whether variation in utilization rates between health areas is higher than would be expected by chance, 2 estimating the statistical power of the variation statistics; and 3 evaluating the ability of different statistics to compare the variability among different procedures regardless of their rates. Methods Parametric bootstrap techniques were used to derive the empirical distribution for each statistic under the hypothesis of homogeneity across areas. Non-parametric procedures were used to analyze the empirical distribution for the observed statistics and compare the results in six situations (low/medium/high utilization rates and low/high variability. A small scale simulation study was conducted to assess the capacity of each statistic to discriminate between different scenarios with different degrees of variation. Results Bootstrap techniques proved to be good at quantifying the difference between the null hypothesis and the variation observed in each situation, and to construct reliable tests and confidence intervals for each of the variation statistics analyzed. Although the good performance of Systematic Component of Variation (SCV, Empirical Bayes (EB statistic shows better behaviour under the null hypothesis, it is able to detect variability if present, it is not influenced by the procedure rate and it is best able to discriminate between different degrees of heterogeneity. Conclusion The EB statistics seems to be a good alternative to more conventional statistics used in small-area variation analysis in health service research because of its robustness.

  19. Studying Variation in Tunes

    NARCIS (Netherlands)

    Janssen, B.; van Kranenburg, P.

    2014-01-01

    Variation in music can be caused by different phenomena: conscious, creative manipulation of musical ideas; but also unconscious variation during music recall. It is the latter phenomenon that we wish to study: variation which occurs in oral transmission, in which a melody is taught without the help

  20. A land use regression application into assessing spatial variation of intra-urban fine particulate matter (PM2.5) and nitrogen dioxide (NO2) concentrations in City of Shanghai, China.

    Science.gov (United States)

    Liu, Chao; Henderson, Barron H; Wang, Dongfang; Yang, Xinyuan; Peng, Zhong-Ren

    2016-09-15

    Intra-urban assessment of air pollution exposure has become a priority study while international attention was attracted to PM2.5 pollution in China in recent years. Land Use Regression (LUR), which has previously been proved to be a feasible way to describe the relationship between land use and air pollution level in European and American cities, was employed in this paper to explain the correlations and spatial variations in Shanghai, China. PM2.5 and NO2 concentrations at 35-45 monitoring locations were selected as dependent variables, and a total of 44 built environmental factors were extracted as independent variables. Only five factors showed significant explanatory value for both PM2.5 and NO2 models: longitude, distance from monitors to the ocean, highway intensity, waterbody area, and industrial land area for PM2.5 model; residential area, distance to the coast, industrial area, urban district, and highway intensity for NO2 model. Respectively, both PM2.5 and NO2 showed anti-correlation with coastal proximity (an indicator of clean air dilution) and correlation with highway and industrial intensity (source indicators). NO2 also showed significant correlation with local indicators of population density (residential intensity and urban classification), while PM2.5 showed significant correlation with regional dilution (longitude as a indicator of distance from polluted neighbors and local water features). Both adjusted R squared values were strong with PM2.5 (0.88) being higher than NO2 (0.62). The LUR was then used to produce continuous concentration fields for NO2 and PM2.5 to illustrate the features and, potentially, for use by future studies. Comparison to PM2.5 studies in New York and Beijing show that Shanghai PM2.5 pollutant distribution was more sensitive to geographic location and proximity to neighboring regions. PMID:27203521

  1. Variation of fundamental constants

    CERN Document Server

    Flambaum, V V

    2006-01-01

    We present a review of recent works devoted to the variation of the fine structure constant alpha, strong interaction and fundamental masses. There are some hints for the variation in quasar absorption spectra, Big Bang nucleosynthesis, and Oklo natural nuclear reactor data. A very promising method to search for the variation of the fundamental constants consists in comparison of different atomic clocks. Huge enhancement of the variation effects happens in transition between accidentally degenerate atomic and molecular energy levels. A new idea is to build a ``nuclear'' clock based on the ultraviolet transition between very low excited state and ground state in Thorium nucleus. This may allow to improve sensitivity to the variation up to 10 orders of magnitude! Huge enhancement of the variation effects is also possible in cold atomic and molecular collisions near Feschbach resonance.

  2. Comparing variation across European countries

    DEFF Research Database (Denmark)

    Thygesen, Lau C; Baixauli-Pérez, Cristobal; Librero-López, Julián;

    2015-01-01

    units of analysis in the estimation of systematic variation in three countries. METHODS: Hospital discharges for six conditions (congestive heart failure, short-term complications of diabetes, hip fracture, knee replacement, prostatectomy in prostate cancer and percutaneous coronary intervention......) produced in Denmark, England and Portugal in 2008 and 2009 were allocated to both original geographical units and new ad hoc areas. New areas were built using Ward's minimum variance methods. The impact of the new areas on variability was assessed using Kernel distribution curves and different statistic...... inhabitants vs. 7% in Denmark and 5% in England. Point estimates for Extremal Quotient and Interquartile Interval Ratio were lower in the three countries, particularly in less prevalent conditions. In turn, the Systematic Component of Variation and Empirical Bayes statistic were slightly lower in more...

  3. Asynchronous Variational Integrators

    OpenAIRE

    Lew, A.; Marsden, J. E.; Ortiz, M.; West, M

    2003-01-01

    We describe a new class of asynchronous variational integrators (AVI) for nonlinear elastodynamics. The AVIs are distinguished by the following attributes: (i) The algorithms permit the selection of independent time steps in each element, and the local time steps need not bear an integral relation to each other; (ii) the algorithms derive from a spacetime form of a discrete version of Hamilton’s variational principle. As a consequence of this variational structure, the algorith...

  4. Calculus of variations

    CERN Document Server

    Gelfand, I M

    2000-01-01

    Based on a series of lectures given by I. M. Gelfand at Moscow State University, this book actually goes considerably beyond the material presented in the lectures. The aim is to give a treatment of the elements of the calculus of variations in a form both easily understandable and sufficiently modern. Considerable attention is devoted to physical applications of variational methods, e.g., canonical equations, variational principles of mechanics, and conservation laws.The reader who merely wishes to become familiar with the most basic concepts and methods of the calculus of variations need on

  5. Managing Cultural Variation in Software Process Improvement

    DEFF Research Database (Denmark)

    Müller, Sune Dueholm; Kræmmergaard, Pernille; Mathiassen, Lars

    The scale and complexity of change in software process improvement (SPI) are considerable and managerial attention to organizational culture during SPI can therefore potentially contribute to successful outcomes. However, we know little about the impact of variations in organizational subculture on...... CMMI level 2 as planned, ASY struggled to implement even modest improvements. To explain these differences, we analyzed the underlying organizational culture within ISY and ASY using two different methods for subculture assessment. The study demonstrates how variations in culture across software...

  6. Genetic variation in dieback resistance

    DEFF Research Database (Denmark)

    Lobo, Albin; Hansen, Jon Kehlet; McKinney, Lea Vig;

    2014-01-01

    -eastern Zealand, Denmark, and confirmed the presence of substantial genetic variation in ash dieback susceptibility. The average crown damage increased in the trial from 61% in 2009 to 66% in 2012 and 72% in 2014, while the estimated heritability was 0.42 in both 2009 and 2012 but increased to 0.53 in 2014....... Genetic correlation between assessments was 0.88 between 2009 and 2012 and 0.91 between 2009 and 2014, suggesting fairly good possibilities for early selection of superior genotypes in the presence of high infection levels in the trial. The level of crown damage had strong negative effect on growth and...

  7. The Variational Fair Autoencoder

    NARCIS (Netherlands)

    C. Louizos; K. Swersky; Y. Li; M. Welling; R. Zemel

    2016-01-01

    We investigate the problem of learning representations that are invariant to certain nuisance or sensitive factors of variation in the data while retaining as much of the remaining information as possible. Our model is based on a variational autoencoding architecture with priors that encourage indep

  8. Heritable epigenetic variation among maize inbreds.

    Directory of Open Access Journals (Sweden)

    Steve R Eichten

    2011-11-01

    Full Text Available Epigenetic variation describes heritable differences that are not attributable to changes in DNA sequence. There is the potential for pure epigenetic variation that occurs in the absence of any genetic change or for more complex situations that involve both genetic and epigenetic differences. Methylation of cytosine residues provides one mechanism for the inheritance of epigenetic information. A genome-wide profiling of DNA methylation in two different genotypes of Zea mays (ssp. mays, an organism with a complex genome of interspersed genes and repetitive elements, allowed the identification and characterization of examples of natural epigenetic variation. The distribution of DNA methylation was profiled using immunoprecipitation of methylated DNA followed by hybridization to a high-density tiling microarray. The comparison of the DNA methylation levels in the two genotypes, B73 and Mo17, allowed for the identification of approximately 700 differentially methylated regions (DMRs. Several of these DMRs occur in genomic regions that are apparently identical by descent in B73 and Mo17 suggesting that they may be examples of pure epigenetic variation. The methylation levels of the DMRs were further studied in a panel of near-isogenic lines to evaluate the stable inheritance of the methylation levels and to assess the contribution of cis- and trans- acting information to natural epigenetic variation. The majority of DMRs that occur in genomic regions without genetic variation are controlled by cis-acting differences and exhibit relatively stable inheritance. This study provides evidence for naturally occurring epigenetic variation in maize, including examples of pure epigenetic variation that is not conditioned by genetic differences. The epigenetic differences are variable within maize populations and exhibit relatively stable trans-generational inheritance. The detected examples of epigenetic variation, including some without tightly linked genetic

  9. Ensembl variation resources

    Directory of Open Access Journals (Sweden)

    Marin-Garcia Pablo

    2010-05-01

    Full Text Available Abstract Background The maturing field of genomics is rapidly increasing the number of sequenced genomes and producing more information from those previously sequenced. Much of this additional information is variation data derived from sampling multiple individuals of a given species with the goal of discovering new variants and characterising the population frequencies of the variants that are already known. These data have immense value for many studies, including those designed to understand evolution and connect genotype to phenotype. Maximising the utility of the data requires that it be stored in an accessible manner that facilitates the integration of variation data with other genome resources such as gene annotation and comparative genomics. Description The Ensembl project provides comprehensive and integrated variation resources for a wide variety of chordate genomes. This paper provides a detailed description of the sources of data and the methods for creating the Ensembl variation databases. It also explores the utility of the information by explaining the range of query options available, from using interactive web displays, to online data mining tools and connecting directly to the data servers programmatically. It gives a good overview of the variation resources and future plans for expanding the variation data within Ensembl. Conclusions Variation data is an important key to understanding the functional and phenotypic differences between individuals. The development of new sequencing and genotyping technologies is greatly increasing the amount of variation data known for almost all genomes. The Ensembl variation resources are integrated into the Ensembl genome browser and provide a comprehensive way to access this data in the context of a widely used genome bioinformatics system. All Ensembl data is freely available at http://www.ensembl.org and from the public MySQL database server at ensembldb.ensembl.org.

  10. Theory of conjectural variations

    CERN Document Server

    Jean-Marie, Alain

    2004-01-01

    We have witnessed in recent years a revival of Conjectural Variations in Game Theory. This reincarnation of an old idea, using a dynamic point of view, aims at combining the adequacy with facts to the requirements of a firmly grounded theory. This book presents, for the first time, a comprehensive account of conjectural variations equilibria in their static inceptions, featuring new comparative results of equilibria with regard to efficiency. It then describes several advances in Dynamic Game Theory, allowing to understand Conjectural Variations Equilibria as dynamic equilibria. The question o

  11. Quantum variational calculus

    CERN Document Server

    Malinowska, Agnieszka B

    2014-01-01

    This Brief puts together two subjects, quantum and variational calculi by considering variational problems involving Hahn quantum operators. The main advantage of its results is that they are able to deal with nondifferentiable (even discontinuous) functions, which are important in applications. Possible applications in economics are discussed. Economists model time as continuous or discrete. Although individual economic decisions are generally made at discrete time intervals, they may well be less than perfectly synchronized in ways discrete models postulate. On the other hand, the usual assumption that economic activity takes place continuously, is nothing else than a convenient abstraction that in many applications is far from reality. The Hahn quantum calculus helps to bridge the gap between the two families of models: continuous and discrete. Quantum Variational Calculus is self-contained and unified in presentation. It provides an opportunity for an introduction to the quantum calculus of variations fo...

  12. Variational Inequalities with Applications

    CERN Document Server

    Sofonea, Mircea

    2009-01-01

    Motivated by stimulating problems in contact mechanics, emphasizing antiplane frictional contact with linearly elastic and viscoelastic materials, this book focuses on the essentials with respect to the qualitative aspects of several classes of variational inequalities (VIs)

  13. Variational principles in physics

    CERN Document Server

    Basdevant, Jean-Louis

    2007-01-01

    Optimization under constraints is an essential part of everyday life. Indeed, we routinely solve problems by striking a balance between contradictory interests, individual desires and material contingencies. This notion of equilibrium was dear to thinkers of the enlightenment, as illustrated by Montesquieu’s famous formulation: "In all magistracies, the greatness of the power must be compensated by the brevity of the duration." Astonishingly, natural laws are guided by a similar principle. Variational principles have proven to be surprisingly fertile. For example, Fermat used variational methods to demonstrate that light follows the fastest route from one point to another, an idea which came to be known as Fermat’s principle, a cornerstone of geometrical optics. Variational Principles in Physics explains variational principles and charts their use throughout modern physics. The heart of the book is devoted to the analytical mechanics of Lagrange and Hamilton, the basic tools of any physicist. Prof. Basdev...

  14. Managing Cultural Variation in Software Process Improvement

    DEFF Research Database (Denmark)

    Kræmmergaard, Pernille; Müller, Sune Dueholm; Mathiassen, Lars

    CMMI level 2 as planned, ASY struggled to implement even modest improvements. To explain these differences, we analyzed the underlying organizational culture within ISY and ASY using two different methods for subculture assessment. The study demonstrates how variations in culture across software...... organizations can have important implications for SPI outcomes. Furthermore, it provides insights into how software managers can practically assess subcultures to inform decisions about and help prepare plans for SPI initiatives....

  15. Generalized quasi variational inequalities

    Energy Technology Data Exchange (ETDEWEB)

    Noor, M.A. [King Saud Univ., Riyadh (Saudi Arabia)

    1996-12-31

    In this paper, we establish the equivalence between the generalized quasi variational inequalities and the generalized implicit Wiener-Hopf equations using essentially the projection technique. This equivalence is used to suggest and analyze a number of new iterative algorithms for solving generalized quasi variational inequalities and the related complementarity problems. The convergence criteria is also considered. The results proved in this paper represent a significant improvement and refinement of the previously known results.

  16. Variational time integrators

    OpenAIRE

    Lew, A.; Marsden, J. E.; Ortiz, M.; West, M

    2004-01-01

    The purpose of this paper is to review and further develop the subject of variational integration algorithms as it applies to mechanical systems of engineering interest. In particular, the conservation properties of both synchronous and asynchronous variational integrators (AVIs) are discussed in detail. We present selected numerical examples which demonstrate the excellent accuracy, conservation and convergence characteristics of AVIs. In these tests, AVIs are found to result in substantial ...

  17. Combined use of meio- and macrobenthic indices to assess complex chemical impacts on a stream ecosystem

    Science.gov (United States)

    McKnight, Ursula S.; Sonne, Anne T.; Rasmussen, Jes J.; Traunspurger, Walter; Höss, Sebastian; Bjerg, Poul L.

    2016-04-01

    habitats for overall ecosystem health, many biological indices tend only to reflect the ecological quality of surface water, rather than of the sedimentary zones where the accumulation of pollutants is often highest. To address this issue, we monitored meiobenthic (i.e. nematodes) and macrobenthic invertebrate communities along a pollution gradient in order to assess the impact of multiple stressors on a groundwater-fed stream, and thus quantify the link between chemical and ecological status. The studied stressors included point source pollutants originating from contaminated groundwater and aquaculture, and diffuse source pollutants originating from conventional agriculture and urban areas. The use of macrofauna is now well-accepted for assessing ecological integrity in aquatic ecosystems, but less is known about the application of meiofaunal community indicators. High abundance and ubiquitous distribution are two potential advantages for including meiofaunal indicators, and notably - for the case of groundwater-surface water interactions - they are particularly suitable for identifying changes in environmental conditions over smaller spatial scales. The results indicate a change in community composition for both meio- and macrobenthic fauna, pointing towards the presence of a local impact resulting from the discharging contaminated groundwater, which extends downstream along a dilution gradient of the groundwater contaminants. Ecological impacts could be linked to xenobiotic compounds coming from groundwater (both chlorinated solvents and pharmaceuticals), as well as the presence of trace metals of diffuse and/or biogenic origin.

  18. Chromatic variations suppress suprathreshold brightness variations.

    Science.gov (United States)

    Kingdom, Frederick A A; Bell, Jason; Gheorghiu, Elena; Malkoc, Gokhan

    2010-01-01

    Most objects in natural scenes are suprathreshold in both color (chromatic) and luminance contrast. How salient is each dimension? We have developed a novel method employing a stimulus similar to that used by B. C. Regan and J. D. Mollon (1997) who studied the relative saliencies of the two chromatic cardinal directions. Our stimuli consist of left- and right-oblique modulations of color and/or luminance defined within a lattice of circles. In the "separated" condition, the two modulations were presented separately as forced-choice pairs, and the task was to indicate which was more salient. In the "combined" condition, the two orthogonal-in-orientation modulations were added, and the task was to indicate the more salient orientation. The ratio of color to luminance contrast at the PSE was calculated for both conditions. Across color directions, 48% more luminance contrast relative to color contrast was required to achieve a PSE in the "combined" compared to the "separated" condition. A second experiment showed that the PSE difference was due to the luminance being masked by the color, rather than due to superior color grouping. We conclude that suprathreshold brightness variations are masked by suprathreshold color variations. PMID:20884478

  19. Variation in Metaphor Variation in Metaphor

    Directory of Open Access Journals (Sweden)

    Zóltan Kövecses

    2010-05-01

    Full Text Available

    Cognitive linguists have so far paid a great deal of attention to the emarkable universality of many conceptual metaphors. However, their theories fail to account for the equally impressive diversity of metaphorical conceptualization both across and within cultures. The present paper is an attempt to lay down the foundations of a theory of metaphor that is capable of simultaneously accounting for both universality and variation in metaphor.

     

    Cognitive linguists have so far paid a great deal of attention to the emarkable universality of many conceptual metaphors. However, their theories fail to account for the equally impressive diversity of metaphorical conceptualization both across and within cultures. The present paper is an attempt to lay down the foundations of a theory of metaphor that is capable of simultaneously accounting for both universality and variation in metaphor.

  20. Explaining Variation in Child Labor Statistics

    OpenAIRE

    Dillon, Andrew; Bardasi, Elena; Beegle, Kathleen; Serneels, Pieter

    2010-01-01

    Child labor statistics are critical for assessing the extent and nature of child labor activities in developing countries. In practice, widespread variation exists in how child labor is measured. Questionnaire modules vary across countries and within countries over time along several dimensions, including respondent type and the structure of the questionnaire. Little is known about the eff...

  1. A case study of intragenomic ITS variation in bryophytes: Assessment of gene flow and role of polyploidy in the origin of European taxa of the Tortula muralis (Musci: Pottiaceae) complex

    Czech Academy of Sciences Publication Activity Database

    Košnar, J.; Herbstová, Miroslava; Kolář, Filip; Koutecký, P.; Kučera, J.

    2012-01-01

    Roč. 61, č. 4 (2012), s. 709-720. ISSN 0040-0262 Institutional research plan: CEZ:AV0Z50510513; CEZ:AV0Z60050516 Institutional support: RVO:60077344 ; RVO:67985939 Keywords : bryophytes * gene flow * intragenomic variation * Tortula Subject RIV: EF - Botanics; EF - Botanics (BU-J) Impact factor: 2.782, year: 2012

  2. Mediterranean sea level variations.

    Science.gov (United States)

    Vigo, I.; Sánchez Reales, J. M.; García, D.; Chao, B. F.

    2009-04-01

    In this work we report an updated study of the sea level variations for the Mediterranean sea for the period from October 1992 to January 2008. The study addresses two mayor issues: (i)The analysis of the spatial and temporal variability of sea surface height (SSH) from radar altimetry measurements (from TOPEX/Poseidon (T/P) + Jason-1, etc.). We use EOF analysis to explain most of its interannual variation, and how the different basins interact. (ii) The analysis of dynamics and balance of water mass transport for the whole period. We estimate the steric SSH by combining the steric SSH estimated from temperature and salt profiles simulated by the ECCO model with time-variable gravity (TVG) data (from GRACE) for the Mediterranean Sea. The estimated steric SSH together with the SSH obtained from altimetry allow for a more realistic estimation of the water mass variations in the Mediterranean for the whole period.

  3. Variation and Synthetic Speech

    CERN Document Server

    Miller, C; Massey, N; Miller, Corey; Karaali, Orhan; Massey, Noel

    1997-01-01

    We describe the approach to linguistic variation taken by the Motorola speech synthesizer. A pan-dialectal pronunciation dictionary is described, which serves as the training data for a neural network based letter-to-sound converter. Subsequent to dictionary retrieval or letter-to-sound generation, pronunciations are submitted a neural network based postlexical module. The postlexical module has been trained on aligned dictionary pronunciations and hand-labeled narrow phonetic transcriptions. This architecture permits the learning of individual postlexical variation, and can be retrained for each speaker whose voice is being modeled for synthesis. Learning variation in this way can result in greater naturalness for the synthetic speech that is produced by the system.

  4. Essential Variational Poisson Cohomology

    Science.gov (United States)

    De Sole, Alberto; Kac, Victor G.

    2012-08-01

    In our recent paper "The variational Poisson cohomology" (2011) we computed the dimension of the variational Poisson cohomology {{{H}^bullet_K({V})}} for any quasiconstant coefficient ℓ × ℓ matrix differential operator K of order N with invertible leading coefficient, provided that {{{V}}} is a normal algebra of differential functions over a linearly closed differential field. In the present paper we show that, for K skewadjoint, the {{{Z}}} -graded Lie superalgebra {{{H}^bullet_K({V})}} is isomorphic to the finite dimensional Lie superalgebra {{widetilde{H}(Nell,S)}} . We also prove that the subalgebra of "essential" variational Poisson cohomology, consisting of classes vanishing on the Casimirs of K, is zero. This vanishing result has applications to the theory of bi-Hamiltonian structures and their deformations. At the end of the paper we consider also the translation invariant case.

  5. Asynchronous Variational Contact Mechanics

    CERN Document Server

    Vouga, Etienne; Tamstorf, Rasmus; Grinspun, Eitan

    2010-01-01

    An asynchronous, variational method for simulating elastica in complex contact and impact scenarios is developed. Asynchronous Variational Integrators (AVIs) are extended to handle contact forces by associating different time steps to forces instead of to spatial elements. By discretizing a barrier potential by an infinite sum of nested quadratic potentials, these extended AVIs are used to resolve contact while obeying momentum- and energy-conservation laws. A series of two- and three-dimensional examples illustrate the robustness and good energy behavior of the method.

  6. Prostate Contouring Variation: Can It Be Fixed?

    International Nuclear Information System (INIS)

    Purpose: To assess whether an education program on CT and MRI prostate anatomy would reduce inter- and intraobserver prostate contouring variation among experienced radiation oncologists. Methods and Materials: Three patient CT and MRI datasets were selected. Five radiation oncologists contoured the prostate for each patient on CT first, then MRI, and again between 2 and 4 weeks later. Three education sessions were then conducted. The same contouring process was then repeated with the same datasets and oncologists. The observer variation was assessed according to changes in the ratio of the encompassing volume to intersecting volume (volume ratio [VR]), across sets of target volumes. Results: For interobserver variation, there was a 15% reduction in mean VR with CT, from 2.74 to 2.33, and a 40% reduction in mean VR with MRI, from 2.38 to 1.41 after education. A similar trend was found for intraobserver variation, with a mean VR reduction for CT and MRI of 9% (from 1.51 to 1.38) and 16% (from 1.37 to 1.15), respectively. Conclusion: A well-structured education program has reduced both inter- and intraobserver prostate contouring variations. The impact was greater on MRI than on CT. With the ongoing incorporation of new technologies into routine practice, education programs for target contouring should be incorporated as part of the continuing medical education of radiation oncologists.

  7. Natural 14C variations

    International Nuclear Information System (INIS)

    This thesis deals with the natural variations in the atmospheric 14C activity, their geophysical origin and their impact on radiocarbon dating. Studies confirm the idea that one is dealing with a mechanism of a certain regularity. The correlation between a 14C variation during the Little Ice Age and the absence of sunspots on the solar surface suggest the sun to be responsible for some kind of modulation of the galactic cosmic ray spectrum. The background of a changing natural 14C level is relevant when studying the antropogenic perturbation of the atmospheric 14C concentration by the addition of CO2 from fossil fuel combustion. The results presented point to a Suess effect over the past 150 years of about 20 per thousand, but also show a local dilution effect. If this local effect is present over large continental parts of the Northern Hemisphere this will put limits to the use of tree ring 14C measurements for testing carbon reservoir models. Finally the influence of 14C variations upon the interpretations of 14C dates for archaeological and geological purposes has been investigated. It is shown that care must be taken especially in the interpretation of highly accurate 14C data of material only covering a few years of growth. One geological example illustrates that 14C variations can easily be interpretated as alternating fast and slow rises of the sea level. (Auth.)

  8. Variational transition state theory

    Energy Technology Data Exchange (ETDEWEB)

    Truhlar, D.G. [Univ. of Minnesota, Minneapolis (United States)

    1993-12-01

    This research program involves the development of variational transition state theory (VTST) and semiclassical tunneling methods for the calculation of gas-phase reaction rates and selected applications. The applications are selected for their fundamental interest and/or their relevance to combustion.

  9. Seasonal Variation in Epidemiology

    Science.gov (United States)

    Marrero, Osvaldo

    2013-01-01

    Seasonality analyses are important in medical research. If the incidence of a disease shows a seasonal pattern, then an environmental factor must be considered in its etiology. We discuss a method for the simultaneous analysis of seasonal variation in multiple groups. The nuts and bolts are explained using simple trigonometry, an elementary…

  10. Bounded variation and around

    CERN Document Server

    Appell, Jürgen; Merentes Díaz, Nelson José

    2013-01-01

    This monographis a self-contained exposition of the definition and properties of functionsof bounded variation and their various generalizations; the analytical properties of nonlinear composition operators in spaces of such functions; applications to Fourier analysis, nonlinear integral equations, and boundary value problems. The book is written for non-specialists. Every chapter closes with a list of exercises and open problems.

  11. Variation and Linguistic Theory.

    Science.gov (United States)

    Bailey, Charles-James N.

    This volume presents principles and models for describing language variation, and introduces a time-based, dynamic framework for linguistic description. The book first summarizes some of the problems of grammatical description encountered from Saussure through the present and then outlines possibilities for new descriptions of language which take…

  12. Gorilla genome structural variation reveals evolutionary parallelisms with chimpanzee

    OpenAIRE

    Ventura, M.; C. R. Catacchio; Alkan, C.; Marques-Bonet, T.; Sajjadian, S.; Graves, T A; Hormozdiari, F; Navarro, A; Malig, M.; Baker, C.; C. Lee; Turner, E H; Chen, L.; Kidd, J. M.; Archidiacono, N

    2011-01-01

    Structural variation has played an important role in the evolutionary restructuring of human and great ape genomes. Recent analyses have suggested that the genomes of chimpanzee and human have been particularly enriched for this form of genetic variation. Here, we set out to assess the extent of structural variation in the gorilla lineage by generating 10-fold genomic sequence coverage from a western lowland gorilla and integrating these data into a physical and cytogenetic framework of struc...

  13. Diurnal variations of Titan

    Science.gov (United States)

    Cui, J.; Galand, M.; Yelle, R. V.; Vuitton, V.; Wahlund, J.-E.; Lavvas, P. P.; Mueller-Wodarg, I. C. F.; Kasprzak, W. T.; Waite, J. H.

    2009-04-01

    We present our analysis of the diurnal variations of Titan's ionosphere (between 1,000 and 1,400 km) based on a sample of Ion Neutral Mass Spectrometer (INMS) measurements in the Open Source Ion (OSI) mode obtained from 8 close encounters of the Cassini spacecraft with Titan. Though there is an overall ion depletion well beyond the terminator, the ion content on Titan's nightside is still appreciable, with a density plateau of ~700 cm-3 below ~1,300 km. Such a plateau is associated with the combination of distinct diurnal variations of light and heavy ions. Light ions (e.g. CH5+, HCNH+, C2H5+) show strong diurnal variation, with clear bite-outs in their nightside distributions. In contrast, heavy ions (e.g. c-C3H3+, C2H3CNH+, C6H7+) present modest diurnal variation, with significant densities observed on the nightside. We propose that the distinctions between light and heavy ions are associated with their different chemical loss pathways, with the former primarily through "fast" ion-neutral chemistry and the latter through "slow" electron dissociative recombination. The INMS data suggest day-to-night transport as an important source of ions on Titan's nightside, to be distinguished from the conventional scenario of auroral ionization by magnetospheric particles as the only ionizing source on the nightside. This is supported by the strong correlation between the observed night-to-day ion density ratios and the associated ion lifetimes. We construct a time-dependent ion chemistry model to investigate the effects of day-to-night transport on the ionospheric structures of Titan. The predicted diurnal variation has similar general characteristics to those observed, with some apparent discrepancies which could be reconciled by imposing fast horizontal thermal winds in Titan's upper atmosphere.

  14. Uniformity in a Dual Assessment System

    OpenAIRE

    Chicoine, David L.; Giertz, J. Fred

    1988-01-01

    Variation in property tax assessment uniformity is studied using data from a "dual" assessment structure where county assessment authority overlaps township assessing responsibility and elected local assessors work with appointed county assessment officers. Particular attention is given to the impact of the size and organization of assessment jurisdictions on assessment uniformity.

  15. Classifying Measures of Biological Variation

    OpenAIRE

    Gregorius, Hans-Rolf; Gillet, Elizabeth M

    2015-01-01

    Biological variation is commonly measured at two basic levels: variation within individual communities, and the distribution of variation over communities or within a metacommunity. We develop a classification for the measurement of biological variation on both levels: Within communities into the categories of dispersion and diversity, and within metacommunities into the categories of compositional differentiation and partitioning of variation. There are essentially two approaches to characte...

  16. The variational Poisson cohomolgy

    CERN Document Server

    De Sole, Alberto

    2011-01-01

    It is well known that the validity of the so called Lenard-Magri scheme of integrability of a bi-Hamiltonian PDE can be established if one has some precise information on the corresponding 1st variational Poisson cohomology for one of the two Hamiltonian operators. In the first part of the paper we explain how to introduce various cohomology complexes, including Lie superalgebra and Poisson cohomology complexes, and basic and reduced Lie conformal algebra and Poisson vertex algebra cohomology complexes, by making use of the corresponding universal Lie superalebra or Lie conformal superalgebra. The most relevant are certain subcomplexes of the basic and reduced Poisson vertex algebra cohomology complexes, which we identify (non-canonically) with the generalized de Rham complex and the generalized variational complex. In the second part of the paper we compute the cohomology of the generalized de Rham complex, and, via a detailed study of the long exact sequence, we compute the cohomology of the generalized var...

  17. Automatic Differentiation Variational Inference

    OpenAIRE

    Kucukelbir, Alp; Tran, Dustin; Ranganath, Rajesh; Gelman, Andrew; Blei, David M.

    2016-01-01

    Probabilistic modeling is iterative. A scientist posits a simple model, fits it to her data, refines it according to her analysis, and repeats. However, fitting complex models to large data is a bottleneck in this process. Deriving algorithms for new models can be both mathematically and computationally challenging, which makes it difficult to efficiently cycle through the steps. To this end, we develop automatic differentiation variational inference (ADVI). Using our method, the scientist on...

  18. Planar theory made variational

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, A.D.; Lande, A.; Smith, R.A.

    1985-04-08

    Within the framework of boson parquet-diagram summations in perturbation theory, we show analytically that several simple approximations lead inevitably to the radial distribution function g(r) which would be obtained with the Jastrow hypernetted-chain variational method. This is the first derivation of the Jastrow result from perturbation theory. Without mentioning pair correlation functions, we have a clear interpretation of g(r) and the structure function, S(k), in terms of diagram sums.

  19. Planar theory made variational

    International Nuclear Information System (INIS)

    Within the framework of boson parquet-diagram summations in perturbation theory, we show analytically that several simple approximations lead inevitably to the radial distribution function g(r) which would be obtained with the Jastrow hypernetted-chain variational method. This is the first derivation of the Jastrow result from perturbation theory. Without mentioning pair correlation functions, we have a clear interpretation of g(r) and the structure function, S(k), in terms of diagram sums

  20. Canonical variate regression.

    Science.gov (United States)

    Luo, Chongliang; Liu, Jin; Dey, Dipak K; Chen, Kun

    2016-07-01

    In many fields, multi-view datasets, measuring multiple distinct but interrelated sets of characteristics on the same set of subjects, together with data on certain outcomes or phenotypes, are routinely collected. The objective in such a problem is often two-fold: both to explore the association structures of multiple sets of measurements and to develop a parsimonious model for predicting the future outcomes. We study a unified canonical variate regression framework to tackle the two problems simultaneously. The proposed criterion integrates multiple canonical correlation analysis with predictive modeling, balancing between the association strength of the canonical variates and their joint predictive power on the outcomes. Moreover, the proposed criterion seeks multiple sets of canonical variates simultaneously to enable the examination of their joint effects on the outcomes, and is able to handle multivariate and non-Gaussian outcomes. An efficient algorithm based on variable splitting and Lagrangian multipliers is proposed. Simulation studies show the superior performance of the proposed approach. We demonstrate the effectiveness of the proposed approach in an [Formula: see text] intercross mice study and an alcohol dependence study. PMID:26861909

  1. Variations in pre-hospital fibrinolysis process of care: insights from the Assessment of the Safety and Efficacy of a New Thrombolytic 3 Plus international acute myocardial infarction pre-hospital care survey.

    NARCIS (Netherlands)

    Welsh, R.C.; Goldstein, P.; Adgey, J.; Verheugt, F.W.A.; Bestilny, S.A.; Wallentin, L.; Werf, F. van de; Armstrong, P.W.

    2004-01-01

    The Assessment of the Safety and Efficacy of a New Thrombolytic 3 (ASSENT 3 PLUS) Plus trial (n=1639) was an international trial of pre-hospital fibrinolysis with tenecteplase randomly assigned to enoxaparin or unfractionated heparin, involving 106 sites in 12 countries. Given the potential impact o

  2. Individual variation in serum cholesterol levels.

    OpenAIRE

    Hegsted, D. M.; Nicolosi, R J

    1987-01-01

    The intraindividual variances in serum/plasma cholesterol levels from a variety of sources have been examined. It is apparent that these are very substantial with mean coefficients of variation usually between 5% and 10%, even when the diet is controlled in metabolic studies. Some subjects show extreme variability from one blood sample to the next. Thus, it is very difficult to assess the degree of risk of individuals according to the guidelines provided by the Consensus Conference on lowerin...

  3. Introduction to global variational geometry

    CERN Document Server

    Krupka, Demeter

    2015-01-01

    The book is devoted to recent research in the global variational theory on smooth manifolds. Its main objective is an extension of the classical variational calculus on Euclidean spaces to (topologically nontrivial) finite-dimensional smooth manifolds; to this purpose the methods of global analysis of differential forms are used. Emphasis is placed on the foundations of the theory of variational functionals on fibered manifolds - relevant geometric structures for variational principles in geometry, physical field theory and higher-order fibered mechanics. The book chapters include: - foundations of jet bundles and analysis of differential forms and vector fields on jet bundles, - the theory of higher-order integral variational functionals for sections of a fibred space, the (global) first variational formula in infinitesimal and integral forms- extremal conditions and the discussion of Noether symmetries and generalizations,- the inverse problems of the calculus of variations of Helmholtz type- variational se...

  4. Harmonically excited orbital variations

    International Nuclear Information System (INIS)

    Rephrasing the equations of motion for orbital maneuvers in terms of Lagrangian generalized coordinates instead of Newtonian rectangular cartesian coordinates can make certain harmonic terms in the orbital angular momentum vector more readily apparent. In this formulation the equations of motion adopt the form of a damped harmonic oscillator when torques are applied to the orbit in a variationally prescribed manner. The frequencies of the oscillator equation are in some ways unexpected but can nonetheless be exploited through resonant forcing functions to achieve large secular variations in the orbital elements. Two cases are discussed using a circular orbit as the control case: (1) large changes in orbital inclination achieved by harmonic excitation rather than one impulsive velocity change, and (2) periodic and secular changes to the longitude of the ascending node using both stable and unstable excitation strategies. The implications of these equations are also discussed for both artificial satellites and natural satellites. For the former, two utilitarian orbits are suggested, each exploiting a form of harmonic excitation. 5 refs

  5. Dynamics of nonholonomic systems from variational principles embedded variation identity

    International Nuclear Information System (INIS)

    Nondeterminacy of dynamics, i.e., the nonholonomic or the vakonomic, fundamental variational principles, e.g., the Lagrange-d'Alembert or Hamiltonian, and variational operators, etc., of nonholonomic mechanical systems can be attributed to the non-uniqueness of ways how to realize nonholonomic constraints. Making use of a variation identity of nonholonomic constraints embedded into the Hamilton's principle with the method of Lagrange undetermined multipliers, three kinds of dynamics for the nonholonomic systems including the vakonomic and nonholonomic ones and a new one are obtained if the variation is respectively reduced to three conditional variations: vakonomic variation, Hoelder's variation and Suslov's variation, defined by the identity. Therefore, different dynamics of nonholonomic systems can be derived from an integral variational principle, utilizing one way of embedding constraints into the principle, with different variations. It is verified that the similar embedding of the identity into the Lagrange-d'Alembert principle gives rise to the nonholonomic dynamics but fails to give the vakonomic one unless the constraints are integrable.

  6. Life-history variation of drosophila subobscura under lead pollution depends on population history

    OpenAIRE

    Kenig Bojan; Patenković Aleksandra; Anđelković Marko; Stamenković-Rada Marina

    2014-01-01

    Contamination represents environmental stress that can affect genetic variability of populations, thus influencing the evolutionary processes. In this study, we evaluate the relationship between heavy metal contamination (Pb) and phenotypic variation, assessed by coefficients of variation (CV) of life-history traits. To investigate the consequences of population origin on variation of life history traits in Drosophila subobscura in response to different lab...

  7. Copy number variation in the bovine genome

    Directory of Open Access Journals (Sweden)

    Bendixen Christian

    2010-05-01

    Full Text Available Abstract Background Copy number variations (CNVs, which represent a significant source of genetic diversity in mammals, have been shown to be associated with phenotypes of clinical relevance and to be causative of disease. Notwithstanding, little is known about the extent to which CNV contributes to genetic variation in cattle. Results We designed and used a set of NimbleGen CGH arrays that tile across the assayable portion of the cattle genome with approximately 6.3 million probes, at a median probe spacing of 301 bp. This study reports the highest resolution map of copy number variation in the cattle genome, with 304 CNV regions (CNVRs being identified among the genomes of 20 bovine samples from 4 dairy and beef breeds. The CNVRs identified covered 0.68% (22 Mb of the genome, and ranged in size from 1.7 to 2,031 kb (median size 16.7 kb. About 20% of the CNVs co-localized with segmental duplications, while 30% encompass genes, of which the majority is involved in environmental response. About 10% of the human orthologous of these genes are associated with human disease susceptibility and, hence, may have important phenotypic consequences. Conclusions Together, this analysis provides a useful resource for assessment of the impact of CNVs regarding variation in bovine health and production traits.

  8. Functional characterization of variations on regulatory motifs.

    Directory of Open Access Journals (Sweden)

    Michal Lapidot

    2008-03-01

    Full Text Available Transcription factors (TFs regulate gene expression through specific interactions with short promoter elements. The same regulatory protein may recognize a variety of related sequences. Moreover, once they are detected it is hard to predict whether highly similar sequence motifs will be recognized by the same TF and regulate similar gene expression patterns, or serve as binding sites for distinct regulatory factors. We developed computational measures to assess the functional implications of variations on regulatory motifs and to compare the functions of related sites. We have developed computational means for estimating the functional outcome of substituting a single position within a binding site and applied them to a collection of putative regulatory motifs. We predict the effects of nucleotide variations within motifs on gene expression patterns. In cases where such predictions could be compared to suitable published experimental evidence, we found very good agreement. We further accumulated statistics from multiple substitutions across various binding sites in an attempt to deduce general properties that characterize nucleotide substitutions that are more likely to alter expression. We found that substitutions involving Adenine are more likely to retain the expression pattern and that substitutions involving Guanine are more likely to alter expression compared to the rest of the substitutions. Our results should facilitate the prediction of the expression outcomes of binding site variations. One typical important implication is expected to be the ability to predict the phenotypic effect of variation in regulatory motifs in promoters.

  9. On the Variational Problems without Having Desired Variational Symmetries

    Directory of Open Access Journals (Sweden)

    Mehdi Nadjafikhah

    2013-01-01

    Full Text Available We will have an attempt to present a method for constructing variational problems without having a desired one-parameter transformation group as a variational symmetry. For this, we use the notation of μ-symmetry which was introduced by Giuseppe Gaeta and Paola Morando in 2004. Moreover, our given method enabled us to solve those constructed variational problems using μ-symmetries.

  10. FROG - Fingerprinting Genomic Variation Ontology.

    Directory of Open Access Journals (Sweden)

    E Abinaya

    Full Text Available Genetic variations play a crucial role in differential phenotypic outcomes. Given the complexity in establishing this correlation and the enormous data available today, it is imperative to design machine-readable, efficient methods to store, label, search and analyze this data. A semantic approach, FROG: "FingeRprinting Ontology of Genomic variations" is implemented to label variation data, based on its location, function and interactions. FROG has six levels to describe the variation annotation, namely, chromosome, DNA, RNA, protein, variations and interactions. Each level is a conceptual aggregation of logically connected attributes each of which comprises of various properties for the variant. For example, in chromosome level, one of the attributes is location of variation and which has two properties, allosomes or autosomes. Another attribute is variation kind which has four properties, namely, indel, deletion, insertion, substitution. Likewise, there are 48 attributes and 278 properties to capture the variation annotation across six levels. Each property is then assigned a bit score which in turn leads to generation of a binary fingerprint based on the combination of these properties (mostly taken from existing variation ontologies. FROG is a novel and unique method designed for the purpose of labeling the entire variation data generated till date for efficient storage, search and analysis. A web-based platform is designed as a test case for users to navigate sample datasets and generate fingerprints. The platform is available at http://ab-openlab.csir.res.in/frog.

  11. Polarizer reflectivity variations

    International Nuclear Information System (INIS)

    On Shiva the beam energy along the chain is monitored using available reflections and/or transmission through beam steering, splitting, and polarizing optics without the intrusion of any additional glass for diagnostics. On the preamp table the diagnostic signal is obtained from the signal transmitted through turning mirrors. At the input of each chain the signal is obtained from the transmission through one of the mirrors used for the chain input alignment sensor (CHIP). At the chain output the transmission through the final turning mirror is used. These diagnostics have proved stable and reliable. However, one of the prime diagnostic locations is at the output of the beta rod. The energy at this location is measured by collecting small reflections from the last polarizer surface of the beta Pockels cell polarizer package. Unfortunately, calibration of this diagnostic has varied randomly, seldom remaining stable for a week or more. The cause of this fluctuation has been investigated for the past year and'it has been discovered that polarizer reflectivity varies with humidity. This report will deal with the possible causes that were investigated, the evidence that humidity is causing the variation, and the associated mechanism

  12. Diurnal variation of mountain waves

    Directory of Open Access Journals (Sweden)

    R. M. Worthington

    2006-11-01

    Full Text Available Mountain waves could be modified as the boundary layer varies between stable and convective. However case studies show mountain waves day and night, and above e.g. convective rolls with precipitation lines over mountains. VHF radar measurements of vertical wind (1990–2006 confirm a seasonal variation of mountain-wave amplitude, yet there is little diurnal variation of amplitude. Mountain-wave azimuth shows possible diurnal variation compared to wind rotation across the boundary layer.

  13. Anatomic Variations of the Paranasal Sinuses on CT Scan Images

    OpenAIRE

    AR. Talaiepour; Sazgar AA; A. Bagheri

    2005-01-01

    Statement of Problem: Variation in paranasal sinus anatomy as shown on computed tomographic scans is of potential significance for it may pose risks during surgery or predispose to certain pathologic conditions.Purpose: The aim of this study was to assess the relative frequency and concurrence of variations in paranasal sinus anatomy in a given population and to compare the results with previous investigations conducted on different populations.Materials and Methods: All patients over 16 year...

  14. Individual phenotypic variation reduces interaction strengths in a consumer–resource system

    OpenAIRE

    Gibert, Jean P.; Brassil, Chad E.

    2014-01-01

    Natural populations often show variation in traits that can affect the strength of interspecific interactions. Interaction strengths in turn influence the fate of pairwise interacting populations and the stability of food webs. Understanding the mechanisms relating individual phenotypic variation to interaction strengths is thus central to assess how trait variation affects population and community dynamics. We incorporated nonheritable variation in attack rates and handling times into a clas...

  15. The Local-time variations of Lunar Prospector epithermal-neutron data

    OpenAIRE

    Teodoro, L F A; Lawrence, D.J.; Eke, V. R.; Elphic, R. E.; Feldman, W. C.; Maurice, S.; Siegler, M. A.; Paige, D. A.

    2015-01-01

    We assess local-time variations of epithermal-neutron count rates measured by the Lunar Prospector Neutron Spectrometer. We investigate the nature of these variations and find no evidence to support the idea that such variations are caused by diurnal variations of hydrogen concentration across the lunar surface. Rather we find an anticorrelation between instrumental temperature and epithermal-neutron count rate. We have also found that the measured counts are dependent on the temperatures of ...

  16. Variation in content and composition of phenolic compounds in permanent pastures according to botanical variation

    OpenAIRE

    Reynaud, Aurélie; Fraisse, Didier; Cornu, Agnes; Farruggia, Anne; Pujos-Guillot, Estelle; Besle, Jean-Michel; Martin, Bruno; Lamaison, Jean-Louis; Paquet, Denis; Doreau, Michel; Graulet, Benoit

    2010-01-01

    Phenolic compounds contribute to the micronutrient composition of pasture, which in turn may affect animal product composition. To assess the importance and variations in content of these compounds, the polyphenolic and botanical compositions of 24 permanent pastures located in one lowland and two upland regions were studied at equivalent stages of growth. Phenolic fractions were characterized and quantified using HPLC-PDA-ESI-QToF, and the total content was determined by colorimetry over eac...

  17. Biodiversity patterns, environmental drivers and indicator species on a High-temperature Hydrothermal edifice, mid-Atlantic ridge

    KAUST Repository

    Sarrazin, Jozée

    2015-04-25

    Knowledge on quantitative faunal distribution patterns of hydrothermal communities in slow-spreading vent fields is particularly scarce, despite the importance of these ridges in the global mid-ocean system. This study assessed the composition, abundance and diversity of 12 benthic faunal assemblages from various locations on the Eiffel Tower edifice (Lucky Strike vent field, Mid-Atlantic Ridge) and investigated the role of key environmental conditions (temperature, total dissolved iron (TdFe), sulfide (TdS), copper (TdCu) and pH) on the distribution of macro- and meiofaunal species at small spatial scales (< 1 m). There were differences in macro- and meiofaunal community structure between the different sampling locations, separating the hydrothermal community of the Eiffel Tower edifice into three types of microhabitats: (1) cold microhabitats characterized by low temperatures (<6 °C), high TdCu (up to 2.4±1.37 µmol l−1), high pH (up to 7.34±0.13) but low TdS concentrations (<6.98±5.01 µmol l−1); (2) warm microhabitats characterized by warmer temperatures (>6 °C), low pH (<6.5) and high TdS/TdFe concentrations (>12.8 µmol l−1/>1.1 µmol l−1 respectively); and (3) a third microhabitat characterized by intermediate abiotic conditions. Environmental conditions showed more variation in the warm microhabitats than in the cold microhabitats. In terms of fauna, the warm microhabitats had lower macro- and meiofaunal densities, and lower richness and Shannon diversity than the cold microhabitats. Six macrofaunal species (Branchipolynoe seepensis, Amathys lutzi, Bathymodiolus azoricus, Lepetodrilus fucensis, Protolira valvatoides and Chorocaris chacei) and three meiofaunal taxa (Paracanthonchus, Cephalochaetosoma and Microlaimus) were identified as being significant indicator species/taxa of particular microhabitats. Our results also highlight very specific niche separation for copepod juveniles among the different hydrothermal microhabitats. Some sampling

  18. A Theory of Harmonic Variations

    OpenAIRE

    de Piro, Tristram

    2014-01-01

    We consider a class of "harmonic variations" for nonsingular curves, obtained as asymptotic degenerations along bitangents. On a geometric level, we obtain an attractive relationship between the class and the genus of $C$. The distribution of class points in pairs across nonsingular curves with such variations, further suggests applications to understanding covalent bonding in terms of shared electrons.

  19. Colony Variation in Staphylococcus lugdunensis

    OpenAIRE

    Leung, Michael J.; Nuttall, Nichalas; Pryce, Todd M.; Coombs, Geoffrey W; Pearman, John W.

    1998-01-01

    Staphylococcus lugdunensis is being increasingly reported as a pathogen with an outcome resembling that of S. aureus rather than coagulase-negative staphylococci. Recent local isolates exhibited colonial variation that delayed identification and interpretation of clinical significance. Until now previous descriptions have not emphasized colonial variation as an important identifying characteristic of S. lugdunensis.

  20. Variational and quasi-variational inequalities in mechanics

    CERN Document Server

    Kravchuk, Alexander S

    2007-01-01

    The essential aim of the present book is to consider a wide set of problems arising in the mathematical modelling of mechanical systems under unilateral constraints. In these investigations elastic and non-elastic deformations, friction and adhesion phenomena are taken into account. All the necessary mathematical tools are given: local boundary value problem formulations, construction of variational equations and inequalities, and the transition to minimization problems, existence and uniqueness theorems, and variational transformations (Friedrichs and Young-Fenchel-Moreau) to dual and saddle-point search problems. Important new results concern contact problems with friction. The Coulomb friction law and some others are considered, in which relative sliding velocities appear. The corresponding quasi-variational inequality is constructed, as well as the appropriate iterative method for its solution. Outlines of the variational approach to non-stationary and dissipative systems and to the construction of the go...

  1. Influence of land evapotranspiration on climate variations

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A coupled numerical model of the global atmosphere with a qualified biosphere(GOALS/LASG) has been used to assess the nature of the physical mechanisms for land-atmos-phere interactions, and the impacts of the Asian/North American land-surface evapotranspirationon the regional and global climate. This sensitivity study suggests that the simulated climate wouldbe relatively sensitive to land surface evapotranspiration, especially over the Asian regions. Theremoval of evapotranspiration in Asia would create a warmer and drier climate to a certain degree.Furthermore, the surface evapotranspiration anomalies would make a substantial contribution tothe formation and variation of subtropical anticyclones through the changes in monsoon precipita-tion and the β-effect, but also make a large contribution to the variations of the atmosphericcirculation in the Northern Hemisphere and even the globe. Therefore, besides the traditionalperception that we have generally emphasized on the influence of subtropical anticyclonesactivities on the boreal summer precipitation over the regions of eastern China, the surfaceevapotranspiration anomalies, however, also have substantial impacts on the subtropicalanticyclones through the changes in monsoon precipitation. For this reason, the variation in theinternal heating sources of the atmosphere caused by the land surface evapotranspiration and thevapor phase change during the boreal summer is an important external factor forcing the weatherand climate

  2. Statistics, Uncertainty, and Transmitted Variation

    Energy Technology Data Exchange (ETDEWEB)

    Wendelberger, Joanne Roth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-11-05

    The field of Statistics provides methods for modeling and understanding data and making decisions in the presence of uncertainty. When examining response functions, variation present in the input variables will be transmitted via the response function to the output variables. This phenomenon can potentially have significant impacts on the uncertainty associated with results from subsequent analysis. This presentation will examine the concept of transmitted variation, its impact on designed experiments, and a method for identifying and estimating sources of transmitted variation in certain settings.

  3. Predicting global variation in infectious disease severity

    Science.gov (United States)

    Jensen, Per M.; De Fine Licht, Henrik H.

    2016-01-01

    Background and objectives: Understanding the underlying causes for the variation in case-fatality-ratios (CFR) is important for assessing the mechanism governing global disparity in the burden of infectious diseases. Variation in CFR is likely to be driven by factors such as population genetics, demography, transmission patterns and general health status. We present data here that support the hypothsis that changes in CFRs for specific diseases may be the result of serial passage through different hosts. For example passage through adults may lead to lower CFR, whereas passage through children may have the opposite effect. Accordingly changes in CFR may occur in parallel with demographic transitions. Methodology: We explored the predictability of CFR using data obtained from the World Health Organization (WHO) disease databases for four human diseases: mumps, malaria, tuberculosis and leptospirosis and assessed these for association with a range of population characteristics, such as crude birth and death rates, median age of the population, mean body mass index, proportion living in urban areas and tuberculosis vaccine coverage. We then tested this predictive model on Danish historical demographic and population data. Results: Birth rates were the best predictor for mumps and malaria CFR. For tuberculosis CFR death rates were the best predictor and for leptospirosis population density was a significant predictor. Conclusions and implications: CFR predictors differed among diseases according to their biology. We suggest that the overall result reflects an interaction between the forces driving demographic change and the virulence of human-to-human transmitted diseases. PMID:26884415

  4. Representing Term Variation in lemon

    OpenAIRE

    Montiel-Ponsoda, Elena; Aguado de Cea, G.; McCrae, J.

    2011-01-01

    In this contribution our objective is to define term variation, analyze the state of the art, and propose a new classification of term variants according to our representation purposes in lemon, a lexiconontology model to enrich ontologies with linguistic descriptions.

  5. Quality of Variational Trial States

    CERN Document Server

    Lucha, Wolfgang; Lucha, Wolfgang; Schoberl, Franz F.

    1999-01-01

    Besides perturbation theory (which clearly requires the knowledge of the exact unperturbed solution), variational techniques represent the main tool for any investigation of the eigenvalue problem of some semibounded operator H in quantum theory. For a reasonable choice of the employed trial subspace of the domain of H, the lowest eigenvalues of H usually can be located with acceptable precision whereas the trial-subspace vectors corresponding to these eigenvalues approximate, in general, the exact eigenstates of H with much less accuracy. Accordingly, various measures for the accuracy of the approximate eigenstates derived by variational techniques are scrutinized. In particular, the matrix elements of the commutator of the operator H and (suitably chosen) different operators with respect to degenerate approximate eigenstates of H obtained by variational methods are proposed as new criteria for the accuracy of variational eigenstates. These considerations are applied to precisely that Hamiltonian for which t...

  6. Stochastic Annealing for Variational Inference

    OpenAIRE

    Gultekin, San; Zhang, Aonan; Paisley, John

    2015-01-01

    We empirically evaluate a stochastic annealing strategy for Bayesian posterior optimization with variational inference. Variational inference is a deterministic approach to approximate posterior inference in Bayesian models in which a typically non-convex objective function is locally optimized over the parameters of the approximating distribution. We investigate an annealing method for optimizing this objective with the aim of finding a better local optimal solution and compare with determin...

  7. An Overview of Variational Integrators

    OpenAIRE

    Lew, Adrian; Marsden, Jerrold E.; Ortiz, Michael; West, Matthew

    2004-01-01

    The purpose of this paper is to survey some recent advances in variational integrators for both finite dimensional mechanical systems as well as continuum mechanics. These advances include the general development of discrete mechanics, applications to dissipative systems, collisions, spacetime integration algorithms, AVI’s (Asynchronous Variational Integrators), as well as reduction for discrete mechanical systems. To keep the article within the set limits, we will only trea...

  8. Variational Gaussian Process Dynamical Systems

    OpenAIRE

    Damianou, Andreas C.; Titsias, Michalis K.; Lawrence, Neil D.

    2011-01-01

    High dimensional time series are endemic in applications of machine learning such as robotics (sensor data), computational biology (gene expression data), vision (video sequences) and graphics (motion capture data). Practical nonlinear probabilistic approaches to this data are required. In this paper we introduce the variational Gaussian process dynamical system. Our work builds on recent variational approximations for Gaussian process latent variable models to allow for nonlinear dimensional...

  9. Coupled Dark Energy field variation

    OpenAIRE

    García-Zúñiga, Roberto Carlos; Izquierdo, Germán

    2014-01-01

    The variation of the dark energy field is found under the assumption that the dark energy is parametric and interacts with the cold dark matter. Considering that the variation of the field could not exceed the Planck mass, we obtain bounds on the coupling and adiabatic coefficients. Three parameterizations of the adiabatic coefficients are considered and two coupling terms where the energy flows from dark energy to dark matter, or the other way around.

  10. Variational integrators for electric circuits

    International Nuclear Information System (INIS)

    In this contribution, we develop a variational integrator for the simulation of (stochastic and multiscale) electric circuits. When considering the dynamics of an electric circuit, one is faced with three special situations: 1. The system involves external (control) forcing through external (controlled) voltage sources and resistors. 2. The system is constrained via the Kirchhoff current (KCL) and voltage laws (KVL). 3. The Lagrangian is degenerate. Based on a geometric setting, an appropriate variational formulation is presented to model the circuit from which the equations of motion are derived. A time-discrete variational formulation provides an iteration scheme for the simulation of the electric circuit. Dependent on the discretization, the intrinsic degeneracy of the system can be canceled for the discrete variational scheme. In this way, a variational integrator is constructed that gains several advantages compared to standard integration tools for circuits; in particular, a comparison to BDF methods (which are usually the method of choice for the simulation of electric circuits) shows that even for simple LCR circuits, a better energy behavior and frequency spectrum preservation can be observed using the developed variational integrator

  11. Assessing streamflow sensitivity to variations in glacier mass balance

    Science.gov (United States)

    O'Neel, Shad; Hood, Eran; Arendt, Anthony; Sass, Louis

    2014-01-01

    The mountains ringing the Gulf of Alaska (GOA) receive upwards of 4–8 m yr−1 of precipitation (Simpson et al.2005; Weingartner et al. 2005; O’Neel 2012), much of which runs off into productive coastal waters. The alpine landscape is heavily glacierized, and storage and turnover of water by glaciers substantially influences the regional surface water balance (Neal et al. 2010). In turn, the land-to-ocean flux of freshwater impacts the biogeochemistry, physical oceanography, freshwater and marine ecology of the downstream components of the GOA ecosystem (e.g., Royer et al. 2001; Hood and Scott 2008). In this way, the links between terrestrial and ocean ecosystems along the GOA have widespread impacts on regional socioeconomic issues including water and hydropower resources, fish populations, and sea level change (Dorava and Milner 2000; Royer and Grosch 2006; Cherry et al. 2010; Gardner et al. 2013). Moreover, predicting future changes in physical, chemical and biological processes in near-shore ecosystems along the GOA hinges, in part, on developing a robust understanding of water storage and transfer by glaciers through streams to the ocean.

  12. Risks assessment - role of pre-existing genetic variation

    International Nuclear Information System (INIS)

    Previously published research on the epidemiology and molecular basis of genetic or congenital diseases and their occurrence in certain 'ethnic' or isolated populations is discussed to show the significance of consanguinity and 'ethnicity' as contributing factors. A statistical study aiming to correlate malformations with absolutely any environmental factor may miss the significance of defects in a gene pool. This consideration has an obvious significance for the nuclear industry. For example, carriers of Fanconi's anemia appear to have an increased tendency to develop acute myelogenous leukemia. The authors indicate the difficulty in finding a definite molecular basis even for simple Mendelian monogenic disorders such as Tay-Sachs disease. 12 refs., 4 tabs

  13. Variation Analysis of Sphygmogram to Assess Cardiovascular System under Meditation

    Directory of Open Access Journals (Sweden)

    Chuan-Yi Liu

    2009-01-01

    Full Text Available In this article, we studied how meditation affects the characteristics of the cardiovascular system, mainly based on blood pressure waveforms (BPW. Four parameters derived from BPW include the rising slope (h1/t1, normalized height of T wave (h3/h1, normalized height of V3 valley (h4/h1 and normalized height of D wave (h5/h1, where t1 and hi, i = 1, … ,5 are quantitative features of the BPW waveform pattern. A larger value of h1/t1 reflects better heart ejection ability and aorta compliance. A larger value of h3/h1 may infer an arterial system with good elasticity. The decrease (increase of h4/h1 parameter indicates the decrease (increase of peripheral resistance of vessels. A larger value of h5/h1 indicates better artery elasticity and aortic valve function. In comparison with the control group, Zen-meditation practitioners have more after-meditation h1/t1, h3/h1 and h5/h1 increase, with more h4/h1 decrease, with statistical significance (P < 0.05. The observation allows us to infer that Zen meditation may effectively improve relevant characteristics of the cardiovascular system.

  14. Assessing genetic variation in growth and development of potato

    OpenAIRE

    Khan, M. S.

    2012-01-01

    Key words: Potato (Solanum tuberosum L.), segregating population, canopy cover dynamics, tuber bulking dynamics, beta function, thermal time, components of variance, genotype-by-environment interaction (GE), heritability, QTL mapping, QTL-by-environment (QTLE) interaction, complex traits, ecophysiological crop model, GECROS, cultivar choice, maturity type, ideotype breeding, tuber yield. Due to increasing food demand and changing diets potato (Solanum tuberosum L.) is becoming a subsistence...

  15. Temporal Variation of Eutrophication Assessment of Lake Bosomtwe, Ghana

    Directory of Open Access Journals (Sweden)

    Adams Sadick

    2016-06-01

    Full Text Available Bosomtwe Lake is a freshwater lake in the Ashanti Region of Ghana, and is the habitat for many native plant and animal species. It is also a place for tourism and, therefore, the water quality and health status of the lake are vital for conservation of species and tourism. The main objective of this study was to examine the water quality of the lake in relation to nutrient load and possible eutrophication of the lake. It also explored the correlation between some physico-chemical parameters of the lake to inform policy direction on a watershed management strategy of the lake. A total of 40 samples were taken from different parts on the lake for analysis. This was done during the wet and dry seasons in 2012 and 2013. The results showed a general lower concentration of these parameters in the wet season and a higher concentration in the dry season.  The statistical results also indicated a negative correlation between Total Nitrogen and Total Phosphorus (r = -0.839, p = 0.075, Total Nitrogen and Total Dissolved Solid  (r = -0.771, p = 0.125, Total Nitrogen and Dissolved Oxygen (r = -0.749, p = 0.145 and Total Nitrogen and pH (r = -0.754, p = 0.141. However, Total Phosphorus showed a positive correlation with Total Dissolved Solid (r = 0.670, p = 0.216, Dissolved Oxygen  (r = 0.830, p = 0.085, pH (r = 0.546, p = 0.314 and Temperature (r = 0.427, p = 474. The nutrient load on the lake water though low, it has the potential to increase the eutrophication of the lake if not controlled and this will be dangerous for ecological entities within the catchment. The association between TP and TDS should be closely monitored since there was a strong positive correlation between them.  The major setback of this study was unavailability of the facilities to analyse colour, turbidity, faecal coliform, Escherichia coli count, chlorophyll-a, and algal growth in the lake.

  16. Variation in thickness of the large cryosections cut for whole-body autoradiography

    International Nuclear Information System (INIS)

    A method to assess variation in thickness of the large cryosections for whole-body autoradiography (WBARG) was described, and the degree of intraslice and interslice variations were determined for our cryomicrotome system (LKB PMV-2250). Intraslice variation in thickness of the 180 x 80 mm cryosection was 0.72-0.92 μm within the range of section thickness for WBARG (15-50 μm), and interslice variation was 0.89-1.21 μm. These potential variations in section thickness should be kept in mind whenever working with quantitative WBARG. (author)

  17. Variational principle for quasibound states

    International Nuclear Information System (INIS)

    A minimum-variance principle for quasibound states is defined and utilized to investigate the corresponding energy resonances. The variational principle yields simultaneously a resonance energy E and a square-integrable wave function phi, such that minimum variance is obtained for arbitrary variations of a restricted class of square-integrable functions as well as with respect to variations of E. It is further shown that the optimum energy E0 obtained from this method can simultaneously be written as an expectation value of the actual Hamiltonian with respect to phi = phi (E0). The example of the Stark effect in the hydrogen atom is studied. It is shown that the variationally obtained resonance energy coincides with the real part of the complex pole of the m function of Weyl, related to the Green's function of the system under consideration. It is also shown that the corresponding numerical application of the Rayleigh-Ritz variational method only gives meaningful results for field intensities below 0.06 a.u., as compared with the ''exact'' results of Hehenberger, McIntosh, and Brandas

  18. Kernels and ranges in the variational formalism

    International Nuclear Information System (INIS)

    An extension of the concept of variational derivative is introduced which allows one to derive an integral identity in the variational formalism. It is applied to characterize the kernel and range of the variational derivative and the divergence operator. (Auth.)

  19. Wave energy resource assessment for the Indian shelf seas

    Digital Repository Service at National Institute of Oceanography (India)

    SanilKumar, V.; Anoop, T.R.

    As a renewable energy, the assessment of wave power potential around a country is crucial. Knowledge of the temporal and spatial variations of wave energy is required for locating a wave power plant. This study investigates the variations in wave...

  20. Variational Lie derivative and cohomology classes

    Science.gov (United States)

    Palese, Marcella; Winterroth, Ekkehart

    2011-07-01

    We relate cohomology defined by a system of local Lagrangian with the cohomology class of the system of local variational Lie derivative, which is in turn a local variational problem; we show that the latter cohomology class is zero, since the variational Lie derivative `trivializes' cohomology classes defined by variational forms. As a consequence, conservation laws associated with symmetries of the second variational derivative of a local variational problem are globally defined.

  1. Solid mechanics a variational approach

    CERN Document Server

    Dym, Clive L

    2013-01-01

    Solid Mechanics: A Variational Approach, Augmented Edition presents a lucid and thoroughly developed approach to solid mechanics for students engaged in the study of elastic structures not seen in other texts currently on the market. This work offers a clear and carefully prepared exposition of variational techniques as they are applied to solid mechanics. Unlike other books in this field, Dym and Shames treat all the necessary theory needed for the study of solid mechanics and include extensive applications. Of particular note is the variational approach used in developing consistent structural theories and in obtaining exact and approximate solutions for many problems.  Based on both semester and year-long courses taught to undergraduate seniors and graduate students, this text is geared for programs in aeronautical, civil, and mechanical engineering, and in engineering science. The authors’ objective is two-fold: first, to introduce the student to the theory of structures (one- and two-dimensional) as ...

  2. Constrained variational calculus: the second variation (part I)

    CERN Document Server

    Massa, Enrico; Pagani, Enrico; Luria, Gianvittorio

    2010-01-01

    This paper is a direct continuation of arXiv:0705.2362 . The Hamiltonian aspects of the theory are further developed. Within the framework provided by the first paper, the problem of minimality for constrained calculus of variations is analyzed among the class of differentiable curves. A necessary and sufficient condition for minimality is proved.

  3. Storm surge variational assimilation model

    Directory of Open Access Journals (Sweden)

    Shi-li HUANG

    2010-06-01

    Full Text Available To eliminate errors caused by uncertainty of parameters and further improve capability of storm surge forecasting, the variational data assimilation method is applied to the storm surge model based on unstructured grid with high spatial resolution. The method can effectively improve the forecasting accuracy of storm surge induced by typhoon through controlling wind drag force coefficient parameter. The model is first theoretically validated with synthetic data. Then, the real storm surge process induced by the TC 0515 typhoon is forecasted by the variational data assimilation model, and results show the feasibility of practical application.

  4. A variational formulation of electrodynamics

    CERN Document Server

    De Nicola, Antonio

    2007-01-01

    We present a variational formulation of electrodynamics using de Rham even and odd differential forms. Our formulation relies on a variational principle more complete than the Hamilton principle and thus leads to field equations with external sources and permits the derivation of the constitutive relations. We interpret a domain in space-time as an odd de Rham 4-current. This permits a treatment of different types of boundary problems in an unified way. In particular we obtain a smooth transition to the infinitesimal version by using a current with a one point support.

  5. Structure variations of carbonizing lignin

    International Nuclear Information System (INIS)

    The studied lignin is a by-product of the process of ethanol production from eucaliptus. It was heat-treated under inert atmosphere conditions at increasing temperatures from 300C up to 2400C. The structural variations were studied by wide-angle X-ray diffraction, small-angle X-ray scattering and infrared absorption spectroscopy. The bulk and 'real' density of the compacted materials have also been determined as functions of the final temperature. These experimental results enabled us to establish a mechanism of structure variation based on the formation of a turbostratic graphite-like and porous structure within the initially amorphous lignin matrix. (Author)

  6. Variation

    OpenAIRE

    2001-01-01

    Veränderung (lat. variatio) einer melodisch oder harmonisch feststehenden Gestalt als epochen- und stilübergreifendes Kompositionsprinzip und im engeren Sinn als eigenständige, an ein (präexistentes) Thema gebundene Form.

  7. Seasonality in meiofaunal distribution on a tropical beach at Balramgari, northeast coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Chatterji, A; Ansari, Z.A; Mishra, J.K.; Parulekar, A

    in isopods and patchy or contagious in nematodes, turbellaria, amphipoda and cladocera with salinity, pH, chlorophyll-a and POC respectively. Mean grain size of the sediment was highly correlated with the abundance of cladocerans and harpacticods...

  8. The dark side of springs: what drives small-scale spatial patterns of subsurface meiofaunal assemblages?

    OpenAIRE

    Barbara Fiasca; Fabio Stoch; Marie-Josè Olivier; Chafik Maazouzi; Marco Petitta; Alessia Di Cioccio; Diana M.P. Galassi

    2014-01-01

    Springs are amongst the most relevant Groundwater Dependent Ecosystems (GDEs) and are key research environments in freshwater ecology and biology. The strict dependency on ground water of surface spring biodiversity is well known, whereas the biodiversity occurring below the spring is very poorly known. This study analyzes copepod assemblages in the subsurface habitat of a karstic rheo-limnocrenic spring in relation to seventeen environmental parameters. Subsurface copepod assemblages were se...

  9. High Meiofaunal and Nematodes Diversity around Mesophotic Coral Oases in the Mediterranean Sea

    OpenAIRE

    Bianchelli, Silvia; Pusceddu, Antonio; Canese, Simone; Greco, Silvio; Danovaro, Roberto

    2013-01-01

    Although the mesophotic zone of the Mediterranean Sea has been poorly investigated, there is an increasing awareness about its ecological importance for its biodiversity, as fish nursery and for the recruitment of shallow water species. Along with coastal rocky cliffs, isolated coralligenous concretions emerging from muddy bottoms are typical structures of the Mediterranean Sea mesophotic zone. Coralligenous concretions at mesophotic depths in the South Tyrrhenian Sea were investigated to ass...

  10. Macro and meiofaunal abundance in six sandy beaches of Lakshadweep islands

    Digital Repository Service at National Institute of Oceanography (India)

    Ansari, Z.A; Ramani, P.; Rivonker, C.U.; Parulekar, A

    stream_size 6 stream_content_type text/plain stream_name Indian_J_Mar_Sci_19_159.pdf.txt stream_source_info Indian_J_Mar_Sci_19_159.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset=ISO-8859-1 ...

  11. Effect of the brown shrimp Crangon crangon L. on endobenthic macrofauna, meiofauna and meiofaunal grazing rates

    Science.gov (United States)

    Nilsson, Per; Sundbäck, Kristina; Jönsson, Benno

    The effect of natural densities (50 and 100 ind·m -2) of juvenile (intraspecific competition occurred. The difference between the two experiments in the effect of Crangon on meiofauna is thought to be caused by the large difference in macrofaunal biomass between the experiments; the shrimp ate mainly juvenile macrofauna in the longer experiment. Overall, the effect of Crangon on the sediment system was weak, suggesting that other factors (physical and chemical) are more important than epibenthic predation in setting the overall limits for production in this sediment.

  12. Are strandline meiofaunal assemblages affected by a once-only mechanical beach cleaning? Experimental findings

    OpenAIRE

    Gheskiere, T; Vincx, M.; Pison, G.; Degraer, S.

    2006-01-01

    The increasing usage of sandy beaches as recreational resources has forced regional authorities of many tourist countries to remove all litter of fabricated origin and natural wrack from the beach. Consequently, a variety of heavy equipment has been developed during the last decades and is now used almost daily at many beaches. A field experiment, following a ‘before-after-control-impact’ (BACI) design, was conducted at the strandline of De Panne (Belgium) to investigate the impacts of mechan...

  13. Meiofaunal stratification in relation to microbial food in a tropical mangrove mud flat

    Digital Repository Service at National Institute of Oceanography (India)

    Ansari, Z.A; Sreepada, R.A; Matondkar, S.G.P.; Parulekar, A

    The vertical gradients of meiofauna mainly in relation to biochemical changes and microbial abundance in the upper 20 cm of deposit of a mangrove mud flat were studied. Strong vertical gradients in the redox potential (Eh), interstitial water...

  14. Brachial plexus variations during the fetal period.

    Science.gov (United States)

    Woźniak, Jowita; Kędzia, Alicja; Dudek, Krzysztof

    2012-12-01

    The brachial plexus is an important nervous system structure. It can be injured during the perinatal period and by postnatal damage. The goal of this study was to assess human fetal brachial plexus variability. A total of 220 brachial plexuses were surgically prepared from 110 human fetuses aged 14-32 weeks of fetal life (50 females and 60 males) ranging in CRL from 80 to 233 mm. The study incorporated the following methods: dissectional and anthropological, digital image acquisition, digital image processing using Image J and GIMP software, and statistical methods (Statistica 9.0). Symmetry and sexual dimorphism were examined. Anomalies of the brachial plexuses were observed in 117 (53.18 %) cases. No sexual dimorphism was found. It was observed that cord variations occurred more often on the left side. Division variants (33.64 %) occurred most often, but also cords (18.18 %) as well as root nerves and terminal ramifications (15.90 %) were found. Trunk anomalies were rare and occurred in only 5.45 % of plexuses. Three height types of median nerve roots in combination with the nerve were distinguished. In one-third of cases, median nerve root connections were found below the axillary fossa and even half in the proximal part of the humerus. In conclusion, the brachial plexus was characterized for anatomical structural variability. Most often division and cord variations were observed. Anomalies occurred regardless of sex or body side except for cord variants. Brachial plexus variation recognition is significant from the neurosurgical and traumatological point of view. PMID:22945314

  15. Practitioner compression force variation in mammography: A 6-year study

    International Nuclear Information System (INIS)

    The application of breast compression in mammography may be more heavily influenced by the practitioner rather than the client. This could affect image quality and will affect client experience. This study builds on previous research to establish if mammography practitioners vary in the compression force they apply over a six-year period. This longitudinal study assessed 3 consecutive analogue screens of 500 clients within one screening centre in the UK. Recorded data included: practitioner code, applied compression force (daN), breast thickness (mm), BI-RADS® density category and breast dose. Exclusion criteria included: previous breast surgery, previous/ongoing assessment, breast implants. 344 met inclusion criteria. Data analysis: assessed variation of compression force (daN) and breast thickness (mm) over 3 sequential screens to determine whether compression force and breast thickness were affected by practitioner variations. Compression force over the 3 screens varied significantly; variation was highly dependent upon the practitioner who performed the mammogram. Significant thickness and compression force differences over the 3 screens were noted for the same client ( 0.31). When practitioners from different compression force groups performed 3 screens, maximum compression force variations were higher and significantly different (p < 0.0001). The amount of compression force used is highly dependent upon practitioner rather than client. This has implications for radiation dose, patient experience and image quality consistency

  16. Variational approach for quarkonium potentials

    International Nuclear Information System (INIS)

    A variational method based on Coulomb and harmonic oscillator trial functions has been investigated in the context of single and superposition of power potentials which are commonly used for quarkonium systems. Ground state energies being upper bounds are calculated and emerge surprisingly close to their exact values considering the simplicity of the method

  17. Sea level and climate variations

    NARCIS (Netherlands)

    Oerlemans, J.

    1985-01-01

    Review paper, ESA Symposium on Application of Satellite Data to Climate Modelling. Alpbach (Austria) Sea level is an essential component of the climate system, on which many human activities in the coastal zone depend. Climate variations leading to changes in relative sea level are discussed, with

  18. Spatial Variation of Temperature and Precipitation in Bhutan and Links to Vegetation and Land Cover

    OpenAIRE

    Ugyen Dorji; Olesen, Jørgen E.; Bøcher, Peder K; Marit Solveig Seidenkrantz

    2016-01-01

    Bhutan, located in the Himalayas in the South Asian monsoon region, has extremely high variation in elevation, climatic conditions, and land cover despite its small geographical area, as well as great biodiversity. This paper provides the first comprehensive description of climatic conditions in Bhutan. It assesses the spatial variation of temperature and precipitation across the country and evaluates the causes for this variation based on daily data from 70 meteorological stations that have ...

  19. Anatomical variations of paranasal sinuses at multislice computed tomography: what to look for

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, Christiana Maia Nobre Rocha de; Maranhao, Carol Pontes de Miranda [Clinica de Medicina Nuclear e Radiologia de Maceio (Medradius), Maceio, AL (Brazil). Setor de Tomografia Computadorizada; Arraes, Fabiana Maia Nobre Rocha [Clinica Sinus, Maceio, AL (Brazil); Padilha, Igor Gomes; Farias, Lucas de Padua Gomes de; Jatoba, Mayara Stephanie de Araujo; Andrade, Anna Carolina Mendonca de; Padilha, Bruno Gomes [Universidade Federal de Alagoas (UFAL), Maceio, AL (Brazil)

    2011-07-15

    Multislice computed tomography is currently the imaging modality of choice for evaluating paranasal sinuses and adjacent structures. Such a method has been increasingly utilized in the assessment of anatomical variations, allowing their accurate identification with high anatomical details. Some anatomical variations may predispose to sinusal diseases, constituting areas of high risk for injuries and complications during surgical procedures. Therefore, the recognition of such variations is critical in the preoperative evaluation for endoscopic surgery. (author)

  20. Variational integrators in plasma physics

    International Nuclear Information System (INIS)

    To a large extent, research in plasma physics is concerned with the description and analysis of energy and momentum transfer between different scales and different kinds of waves. In the numerical modelling of such phenomena it appears to be crucial to describe the transfer processes preserving the underlying conservation laws in order to prevent physically spurious solutions. In this work, special numerical methods, so called variational integrators, are developed for several models of plasma physics. Special attention is given to conservation properties like conservation of energy and momentum. By design, variational integrators are applicable to all systems that have a Lagrangian formulation. Usually, equations of motion are derived by Hamilton's action principle and then discretised. In the application of the variational integrator theory, the order of these steps is reversed. At first, the Lagrangian and the accompanying variational principle are discretised, such that discrete equations of motion can be obtained directly by applying the discrete variational principle to the discrete Lagrangian. The advantage of this approach is that the resulting discretisation automatically retains the conservation properties of the continuous system. Following an overview of the geometric formulation of classical mechanics and field theory, which forms the basis of the variational integrator theory, variational integrators are introduced in a framework adapted to problems from plasma physics. The applicability of variational integrators is explored for several important models of plasma physics: particle dynamics (guiding centre dynamics), kinetic theory (the Vlasov-Poisson system) and fluid theory (magnetohydrodynamics). These systems, with the exception of guiding centre dynamics, do not possess a Lagrangian formulation to which the variational integrator methodology is directly applicable. Therefore the theory is extended by linking it to Ibragimov's theory of

  1. Center Variation in the Delivery of Indicated Late Preterm Births.

    Science.gov (United States)

    Aliaga, Sofia; Zhang, Jun; Long, D Leann; Herring, Amy H; Laughon, Matthew; Boggess, Kim; Reddy, Uma M; Grantz, Katherine Laughon

    2016-08-01

    Objective Evidence for optimal timing of delivery for some pregnancy complications at late preterm gestation is limited. The purpose of this study was to identify center variation of indicated late preterm births. Study design We performed an analysis of singleton late preterm and term births from a large U.S. retrospective obstetrical cohort. Births associated with spontaneous preterm labor, major congenital anomalies, chorioamnionitis, and emergency cesarean were excluded. We used modified Poisson fixed effects logistic regression with interaction terms to assess center variation of indicated late preterm births associated with four medical/obstetric comorbidities after adjusting for socio-demographics, comorbidities, and hospital/provider characteristics. Results We identified 150,055 births from 16 hospitals; 9,218 were indicated late preterm births. We found wide variation of indicated late preterm births across hospitals. The extent of center variation was greater for births associated with preterm premature rupture of membranes (risk ratio [RR] across sites: 0.45-3.05), hypertensive disorders of pregnancy (RR across sites: 0.36-1.27), and placenta previa/abruption (RR across sites: 0.48-1.82). We found less center variation for births associated with diabetes (RR across sites: 0.65-1.39). Conclusion Practice variation in the management of indicated late preterm deliveries might be a source of preventable late preterm birth. PMID:27120474

  2. Size and shape variation in the proximal femur of Australopithecus africanus.

    Science.gov (United States)

    Harmon, Elizabeth

    2009-06-01

    Aside from use as estimates of body mass dimorphism and fore to hind limb joint size comparisons, postcranial elements have not often contributed to assessments of variation in Australopithecus africanus. Meanwhile, cranial, facial, and dental size variation is interpreted to be high or moderately high. Further, the cranial base and face express patterns of structural (shape) variation, which are interpreted by some as evidence for the presence of multiple species. Here, the proximal femur is used to consider postcranial size and shape variation in A. africanus. Original fossils from Makapansgat and Sterkfontein, and samples from Homo, Pan, Gorilla, and Pongo were measured. Size variation was assessed by comparing the A. africanus coefficient of variation to bootstrapped distributions of coefficient of variation samples for each taxon. Shape variation was assessed from isometrically adjusted shape variables. First, the A. africanus standard deviation of log transformed shape variables was compared to bootstrapped distributions of logged standard deviations in each taxon. Second, shape variable based Euclidean distances between fossil pairs were compared to pairwise Euclidean distance distributions in each reference taxon. The degree of size variation in the A. africanus proximal femur is consistent with that of a single species, and is most comparable to Homo and Pan, lower than A. afarensis, and lower than some estimates of cranial and dental variation. Some, but not all, shape variables show more variation in A. africanus than in extant taxa. The degree of shape difference between some fossils exceeds the majority of pairwise differences in the reference taxa. Proximal femoral shape, but not size, variation is consistent with high estimates of A. africanus cranial variation. PMID:19446306

  3. Geometric constrained variational calculus. III: The second variation (Part II)

    Science.gov (United States)

    Massa, Enrico; Luria, Gianvittorio; Pagani, Enrico

    2016-03-01

    The problem of minimality for constrained variational calculus is analyzed within the class of piecewise differentiable extremaloids. A fully covariant representation of the second variation of the action functional based on a family of local gauge transformations of the original Lagrangian is proposed. The necessity of pursuing a local adaptation process, rather than the global one described in [1] is seen to depend on the value of certain scalar attributes of the extremaloid, here called the corners’ strengths. On this basis, both the necessary and the sufficient conditions for minimality are worked out. In the discussion, a crucial role is played by an analysis of the prolongability of the Jacobi fields across the corners. Eventually, in the appendix, an alternative approach to the concept of strength of a corner, more closely related to Pontryagin’s maximum principle, is presented.

  4. Measurement and Socio-Demographic Variation of Social Capital in a Large Population-Based Survey

    Science.gov (United States)

    Nieminen, Tarja; Martelin, Tuija; Koskinen, Seppo; Simpura, Jussi; Alanen, Erkki; Harkanen, Tommi; Aromaa, Arpo

    2008-01-01

    Objectives: The main objective of this study was to describe the variation of individual social capital according to socio-demographic factors, and to develop a suitable way to measure social capital for this purpose. The similarity of socio-demographic variation between the genders was also assessed. Data and methods: The study applied…

  5. Plasma creatinine in dogs: intra- and inter-laboratory variation in 10 European veterinary laborat

    NARCIS (Netherlands)

    Mrs. Ulleberg, T.; Robben, J.H.; Nordahl, K.; Mr. Ulleberg, T.; Heiene, R.

    2011-01-01

    Abstract BACKGROUND: There is substantial variation in reported reference intervals for canine plasma creatinine among veterinary laboratories, thereby influencing the clinical assessment of analytical results. The aims of the study was to determine the inter- and intra-laboratory variation in plasm

  6. Comparison of circadian variations using FEV1 and peak expiratory flow rates among normal and asthmatic subjects.

    OpenAIRE

    Troyanov, S; Ghezzo, H; Cartier, A; Malo, J.L.

    1994-01-01

    BACKGROUND--Most studies that describe circadian variations in asthma have used maximum rate of peak expiratory flow (PEF) rather than forced expiratory volume in one second (FEV1) to assess airway calibre. This study was designed to assess circadian variations in PEF and FEV1 measured simultaneously and to compare variations in these measurements in normal and asthmatic subjects in a stable clinical state. METHODS--Twenty nine subjects (nine asthmatic subjects on bronchodilators, 10 on inhal...

  7. Variation of Parameters in Differential Equations (A Variation in Making Sense of Variation of Parameters)

    Science.gov (United States)

    Quinn, Terry; Rai, Sanjay

    2012-01-01

    The method of variation of parameters can be found in most undergraduate textbooks on differential equations. The method leads to solutions of the non-homogeneous equation of the form y = u[subscript 1]y[subscript 1] + u[subscript 2]y[subscript 2], a sum of function products using solutions to the homogeneous equation y[subscript 1] and…

  8. Variational Integrators for Reduced Magnetohydrodynamics

    CERN Document Server

    Kraus, Michael; Grasso, Daniela

    2015-01-01

    Reduced magnetohydrodynamics is a simplified set of magnetohydrodynamics equations with applications to both fusion and astrophysical plasmas, possessing a noncanonical Hamiltonian structure and consequently a number of conserved functionals. We propose a new discretisation strategy for these equations based on a discrete variational principle applied to a formal Lagrangian. The resulting integrator preserves important quantities like the total energy, magnetic helicity and cross helicity exactly (up to machine precision). As the integrator is free of numerical resistivity, spurious reconnection along current sheets is absent in the ideal case. If effects of electron inertia are added, reconnection of magnetic field lines is allowed, although the resulting model still possesses a noncanonical Hamiltonian structure. After reviewing the conservation laws of the model equations, the adopted variational principle with the related conservation laws are described both at the continuous and discrete level. We verify...

  9. Bernoulli Variational Problem and Beyond

    KAUST Repository

    Lorz, Alexander

    2013-12-17

    The question of \\'cutting the tail\\' of the solution of an elliptic equation arises naturally in several contexts and leads to a singular perturbation problem under the form of a strong cut-off. We consider both the PDE with a drift and the symmetric case where a variational problem can be stated. It is known that, in both cases, the same critical scale arises for the size of the singular perturbation. More interesting is that in both cases another critical parameter (of order one) arises that decides when the limiting behaviour is non-degenerate. We study both theoretically and numerically the values of this critical parameter and, in the symmetric case, ask if the variational solution leads to the same value as for the maximal solution of the PDE. Finally we propose a weak formulation of the limiting Bernoulli problem which incorporates both Dirichlet and Neumann boundary condition. © 2013 Springer-Verlag Berlin Heidelberg.

  10. Diurnal variation of depressive symptoms

    OpenAIRE

    Wirz-Justice, Anna

    2008-01-01

    Diurnal variation of depressive symptoms appears to be part of the core of depression. Yet longitudinal investigation of an individual's pattern regularity, relation to clinical state, and clinical improvement reveals little homogeneity. Morning lows, afternoon slump, evening worsening - all can occur during a single depressive episode. Mood variability, or the propensity to produce mood swings, appears to be the characteristic that most predicts capacity to respond to treatment. Laboratory s...

  11. Regular Variation and Smile Asymptotics

    OpenAIRE

    Benaim, Shalom; Friz, Peter

    2006-01-01

    We consider risk-neutral returns and show how their tail asymptotics translate directly to asymptotics of the implied volatility smile, thereby sharpening Roger Lee's celebrated moment formula. The theory of regular variation provides the ideal mathematical framework to formulate and prove such results. The practical value of our formulae comes from the vast literature on tail asymptotics and our conditions are often seen to be true by simple inspection of known results.

  12. Global Stress Variation over Time

    Science.gov (United States)

    Yi, H.; Lu, Z.; Wen, L.

    2015-12-01

    Understanding how stress changes over time is important as it is related to studies of earthquake triggering and mantle rheology. We calculate stress variation at the Earth's surface on the global scale from 2003 to 2014, resultant from several major physical forces acting on the Earth. The physical forces we considered include the surface loading due to terrestrial water storage (TWS), force associated with post-glacial rebound (PGR) and tidal loading (including solid tide and ocean tide). The stress change associated with TWS is calculated in this way: we infer TWS from monthly gravity field of the Gravity Recovery and Climate Experiment (GRACE), in which gravity variation associated with PGR has been removed; we then estimate stress change at the Earth's surface as the elastic response of the GRACE-inferred TWS change. The stress change associated with PGR is calculated as the rate of viscoelastic stress change responding to ice loading from ICE-5G model. And, tidal stress is calculated as the elastic response of the Earth to the traction forces of the Sun and the Moon (solid tide) and to the loading of ocean tide. The total stress change is the sum of the stress changes associated with these three types of forces. As first result, in the study period from 2003 to 2014, the radial normal stress variation exhibits a prominent decreasing trend in southern Africa and Queen Maud Land of Antarctica, an increasing trend in Alaska of the US (United States), Greenland and Marie Byrd Land of Antarctica, and strong annual cycles in southern Africa and Alaska of the US. We will present the geographical distribution of global stress variation from 2003 to 2014 and discuss its possible implications.

  13. Longitudinal Variations in Jupiter's Winds

    Science.gov (United States)

    Simon-Miller, Amy A.; Gierasch, P. J.; Tierney, G.

    2010-01-01

    Long-term studies of Jupiter's zonal wind field revealed temporal variations on the order of 20 to 40 m/s at many latitudes, greater than the typical data uncertainties of 1 to 10 m/s. No definitive periodicities were evident, however, though some latitudinally-confined signals did appear at periods relevant to the Quasi- Quadrennial Oscillation (Simon-Miller & Gierasch, Icarus, in press). As the QQO appears, from vertical temperature profiles, to propagate downward, it is unclear why a signal is not more obvious, unless other processes dominate over possibly weaker forcing from the QQO. An additional complication is that zonal wind profiles represent an average over some particular set of longitudes for an image pair and most data sets do not offer global wind coverage. Lien avoiding known features, such as the large anticyclonic vortices especially prevalent in the south, there can be distinct variations in longitude. We present results on the full wind field from Voyager and Cassini data, showing apparent longitudinal variations of up to 60 m/s or more. These are particularly obvious near disruptions such as the South Equatorial Disturbance, even when the feature itself is not clearly visible. These two dates represent very different states of the planet for comparison: Voyagers 1 & 2 flew by Jupiter shortly after a global upheaval, while many regions were in a disturbed state, while the Cassini view is typical of a more quiescent period present during much of the 1990s and early 2000s.

  14. Urbanization Process and Variation of Energy Budget of Land Surfaces

    Directory of Open Access Journals (Sweden)

    Ciro Gardi

    Full Text Available Urban areas are increasing at a rate much higher than human population growth in many part of the world; actually more than 73 towns in the world are larger than 1000 km2. The European Environmental Agency indicates an urban area average growth rate, over the last 20 years, of 20%. The urbanization process, and the consequent soil sealing, determines not only the losses of the ecological functions of the soil, but also a variation of the energy budget of land surfaces, that affect the microclimatic conditions (heat islands. The alteration of the energy budget are determined by the variations of albedo and roughness of surfaces, but especially by the net losses of evapotranspirating areas. In the present research we have assessed the variation of Parma territory energy budget, induced by the change in land use over the last 122 years. The urban area increase between 1881 and 2003 was 535%.

  15. Systematic and Stochastic Variations in Pulsar Dispersion Measures

    Science.gov (United States)

    Lam, M. T.; Cordes, J. M.; Chatterjee, S.; Jones, M. L.; McLaughlin, M. A.; Armstrong, J. W.

    2016-04-01

    We analyze deterministic and random temporal variations in the dispersion measure (DM) from the full three-dimensional velocities of pulsars with respect to the solar system, combined with electron-density variations over a wide range of length scales. Previous treatments have largely ignored pulsars’ changing distances while favoring interpretations involving changes in sky position from transverse motion. Linear trends in pulsar DMs observed over 5–10 year timescales may signify sizable DM gradients in the interstellar medium (ISM) sampled by the changing direction of the line of sight to the pulsar. We show that motions parallel to the line of sight can also account for linear trends, for the apparent excess of DM variance over that extrapolated from scintillation measurements, and for the apparent non-Kolmogorov scalings of DM structure functions inferred in some cases. Pulsar motions through atomic gas may produce bow-shock ionized gas that also contributes to DM variations. We discuss the possible causes of periodic or quasi-periodic changes in DM, including seasonal changes in the ionosphere, annual variations of the solar elongation angle, structure in the heliosphere and ISM boundary, and substructure in the ISM. We assess the solar cycle’s role on the amplitude of ionospheric and solar wind variations. Interstellar refraction can produce cyclic timing variations from the error in transforming arrival times to the solar system barycenter. We apply our methods to DM time series and DM gradient measurements in the literature and assess their consistency with a Kolmogorov medium. Finally, we discuss the implications of DM modeling in precision pulsar timing experiments.

  16. Human performance variation analysis: A process for human performance problem solving

    Directory of Open Access Journals (Sweden)

    Anerie Rademeyer

    2009-04-01

    Full Text Available Problem-solving ability is a much sought-after trait in executives, especially if it includes the ability to solve human performance problems. This paper proposes a systematic root cause analysis process that effectively and consistently uncovers the root causes of human performance problems and controls the causes in a way that prevents the problems from recurring. Applying action research the study brings into being a Human Performance Variation Analysis (HPVA process, which consists of three phases: (1 performance variation assessment, (2 performance variation analysis, and (3 performance variation resolution. The HPVA provides much-needed capability in solving human performance problems in organisations.

  17. K Variations and Anisotropy: Microstructure Effect and Numerical Predictions

    Institute of Scientific and Technical Information of China (English)

    李旭东; 李华清

    2003-01-01

    Computer experiments were performed on simulated polycrystalline material samples that possess locally anisotropic microstructures to investigate stress intensity factor ( K ) variations and anisotropy along fronts of microcracks of different sizes. The anisotropic K , arising from inhomogeneous stresses in broken grains, was determined for planar microcracks by using a weight function-based numerical technique. It has been found that the grain-orientation-geometry-induced local anisotropy produces large variations in K along front of microcracks, when the crack size is of the order of few grain diameters. Synergetic effect of grain orientation and geometry of broken grains control K variations and evolution along the microcrack front. The K variations may diminish at large crack sizes, signifying a shift of K calculation to bulk stress dependence from local stress dependence. Local grain geometry and texture may lead to K anisotropy, producing unusually higher/lower K at a segment of the crack front. Either K variation or anisotropy cannot be ignored when assessing a microcrack.

  18. The affect of tissue depth variation on craniofacial reconstructions.

    Science.gov (United States)

    Starbuck, John M; Ward, Richard E

    2007-10-25

    We examined the affect of tissue depth variation on the reconstruction of facial form, through the application of the American method, utilizing published tissue depth measurements for emaciated, normal, and obese faces. In this preliminary study, three reconstructions were created on reproductions of the same skull for each set of tissue depth measurements. The resulting morphological variation was measured quantitatively using the anthropometric craniofacial variability index (CVI). This method employs 16 standard craniofacial anthropometric measurements and the results reflect "pattern variation" or facial harmony. We report no appreciable variation in the quantitative measure of the pattern facial form obtained from the three different sets of tissue depths. Facial similarity was assessed qualitatively utilizing surveys of photographs of the three reconstructions. Surveys indicated that subjects frequently perceived the reconstructions as representing different individuals. This disagreement indicates that size of the face may blind observers to similarities in facial form. This research is significant because it illustrates the confounding effect that normal human variation contributes in the successful recognition of individuals from a representational three-dimensional facial reconstruction. Research results suggest that successful identification could be increased if multiple reconstructions were created which reflect a wide range of possible outcomes for facial form. The creation of multiple facial images, from a single skull, will be facilitated as computerized versions of facial reconstruction are further developed and refined. PMID:17353107

  19. Numerical simulations of ocean induced variations of Earth's rotation.

    OpenAIRE

    Maik Thomas; Sündermann, J.;  

    2000-01-01

    To investigate non-linear interactions of circulation and tides, an OGCM is additionally forced with the complete astronomical tidal potential. Three model runs with different forcing conditions are analysed to assess the role of the oceans with respect to excitation of polar motion. Secondary effects turn out to influence the Earth's orientation significantly. Hence, a linear superimposition of circulation and tides only partly describes ocean induced variations of Earth's rotation.

  20. Source of variation of isoflavone concentrations in perennial clover species

    OpenAIRE

    Bronislava Butkute; Butkute Lemeziene; Giedre Dabkeviciene; Valdas Jakstas; Egidijus Vilcinskas; Valdimaras Janulis

    2014-01-01

    Introduction: Clover has attracted considerable interest not only as a valuable livestock forage plant, but also as an important source of isoflavones. The current study was aimed to assess the variation of concentration of three isoflavones in clover species grown under a cool temperate climate environment in Lithuania. Materials and Methods: Isoflavone contents were quantified in the plant parts of 21 accessions belonging to five perennial species of genus Trifolium (T. pratense, T. repens,...

  1. Clinically relevant copy number variations detected in cerebral palsy

    OpenAIRE

    Oskoui, Maryam; Gazzellone, Matthew J.; Thiruvahindrapuram, Bhooma; Zarrei, Mehdi; Andersen, John; Wei, John; Wang, Zhuozhi; Wintle, Richard F; Marshall, Christian R.; Cohn, Ronald D; Weksberg, Rosanna; Stavropoulos, Dimitri J; Fehlings, Darcy; Shevell, Michael I.; Stephen W Scherer

    2015-01-01

    Cerebral palsy (CP) represents a group of non-progressive clinically heterogeneous disorders that are characterized by motor impairment and early age of onset, frequently accompanied by co-morbidities. The cause of CP has historically been attributed to environmental stressors resulting in brain damage. While genetic risk factors are also implicated, guidelines for diagnostic assessment of CP do not recommend for routine genetic testing. Given numerous reports of aetiologic copy number variat...

  2. Sex-specific genetic effects influence variation in body composition

    OpenAIRE

    Zillikens, Carola; Yazdanpanah, Mojgan; Pardo Cortes, Luba; Rivadeneira Ramirez, Fernando; Aulchenko, Yurii; Oostra, Ben; Uitterlinden, André; Pols, Huib; Tikka-Kleemola, Päivi

    2008-01-01

    textabstractAims/hypothesis: Despite well-known sex differences in body composition it is not known whether sex-specific genetic or environmental effects contribute to these differences. Methods: We assessed body composition in 2,506 individuals, from a young Dutch genetic isolate participating in the Erasmus Rucphen Family study, by dual-energy X-ray absorptiometry and anthropometry. We used variance decomposition procedures to partition variation of body composition into genetic and environ...

  3. Diurnal variations of Titan's ionosphere

    Science.gov (United States)

    Cui, J.; Galand, M.; Yelle, R. V.; Vuitton, V.; Wahlund, J.-E.; Lavvas, P. P.; Müller-Wodarg, I. C. F.; Cravens, T. E.; Kasprzak, W. T.; Waite, J. H.

    2009-06-01

    We present our analysis of the diurnal variations of Titan's ionosphere (between 1000 and 1300 km) based on a sample of Ion Neutral Mass Spectrometer (INMS) measurements in the Open Source Ion (OSI) mode obtained from eight close encounters of the Cassini spacecraft with Titan. Although there is an overall ion depletion well beyond the terminator, the ion content on Titan's nightside is still appreciable, with a density plateau of ˜700 cm-3 below ˜1300 km. Such a plateau is a combined result of significant depletion of light ions and modest depletion of heavy ones on Titan's nightside. We propose that the distinctions between the diurnal variations of light and heavy ions are associated with their different chemical loss pathways, with the former primarily through “fast” ion-neutral chemistry and the latter through “slow” electron dissociative recombination. The strong correlation between the observed night-to-day ion density ratios and the associated ion lifetimes suggests a scenario in which the ions created on Titan's dayside may survive well to the nightside. The observed asymmetry between the dawn and dusk ion density profiles also supports such an interpretation. We construct a time-dependent ion chemistry model to investigate the effect of ion survival associated with solid body rotation alone as well as superrotating horizontal winds. For long-lived ions, the predicted diurnal variations have similar general characteristics to those observed. However, for short-lived ions, the model densities on the nightside are significantly lower than the observed values. This implies that electron precipitation from Saturn's magnetosphere may be an additional and important contributor to the densities of the short-lived ions observed on Titan's nightside.

  4. Quadratic Variation by Markov Chains

    DEFF Research Database (Denmark)

    Hansen, Peter Reinhard; Horel, Guillaume

    We introduce a novel estimator of the quadratic variation that is based on the the- ory of Markov chains. The estimator is motivated by some general results concerning filtering contaminated semimartingales. Specifically, we show that filtering can in prin- ciple remove the effects of market...... microstructure noise in a general framework where little is assumed about the noise. For the practical implementation, we adopt the dis- crete Markov chain model that is well suited for the analysis of financial high-frequency prices. The Markov chain framework facilitates simple expressions and elegant analyti...

  5. Induced polygenic variation in lentils

    International Nuclear Information System (INIS)

    In a study at the Himachal Pradesh Krishi Vishwa Vidyalay, India microsperma and macrosperma types of lentil seeds were irradiated with 5, 10, 15, 20 and 25 kR of gamma rays to study the nature and magnitude of induced variation in various polygenic traits in both lentil types. Data were recorded for seed yield, biological yield, harvest index, number of pods/plant, 100-seed weight, plant height, time to 50% flowering (days), and time to maturity (days). A sufficient genetic variability was induced for most polygenic traits in both lentil types. However, macrosperma type was found more radio-sensitive

  6. Systematic variations in divergence angle

    CERN Document Server

    Okabe, Takuya

    2012-01-01

    Practical methods for quantitative analysis of radial and angular coordinates of leafy organs of vascular plants are presented and applied to published phyllotactic patterns of various real systems from young leaves on a shoot tip to florets on a flower head. The constancy of divergence angle is borne out with accuracy of less than a degree. It is shown that apparent fluctuations in divergence angle are in large part systematic variations caused by the invalid assumption of a fixed center and/or by secondary deformations, while random fluctuations are of minor importance.

  7. Variational Recurrent Auto-Encoders

    OpenAIRE

    Fabius, Otto; van Amersfoort, Joost R.

    2014-01-01

    In this paper we propose a model that combines the strengths of RNNs and SGVB: the Variational Recurrent Auto-Encoder (VRAE). Such a model can be used for efficient, large scale unsupervised learning on time series data, mapping the time series data to a latent vector representation. The model is generative, such that data can be generated from samples of the latent space. An important contribution of this work is that the model can make use of unlabeled data in order to facilitate supervised...

  8. Variational collocation on finite intervals

    Science.gov (United States)

    Amore, Paolo; Cervantes, Mayra; Fernández, Francisco M.

    2007-10-01

    In this paper, we study a set of functions, defined on an interval of finite width, which are orthogonal and which reduce to the sinc functions when the appropriate limit is taken. We show that these functions can be used within a variational approach to obtain accurate results for a variety of problems. We have applied them to the interpolation of functions on finite domains and to the solution of the Schrödinger equation, and we have compared the performance of the present approach with others.

  9. Sea level variations: past, present and future

    International Nuclear Information System (INIS)

    Sea level varies globally and regionally, on a broad range of temporal scales, in response to climate change and variability, as well as to solid Earth's deformations caused by land ice melt.This article consists of an overview of the most up-to-date results about past and present sea level variations and associated contributions (land ice melt, ocean thermal expansion,land water storage changes). Following a 130 m rise during the last deglaciation, the mean sea level remained almost stable during the last few millennia, until the beginning of the industrial era. During the 20. century, the rate of sea level rise amounted 1.7 ± 0.3 mm/yr on average. Since the early 1990's, the global mean sea level rise has reached 3.2 ± 0.4 mm/yr, as observed by altimeter satellites, but with high regional variations in sea level trends. Over the 1993-2010 time period, the contributions to the global mean rise are from ocean warming (30 to 40%), land ice melt (about 50%) and land water storage change (10 to 15%). The observed regional variability mostly results from non-uniform ocean thermal expansion.We then present future changes in sea level, both in terms of global mean and regional variability, using information from the IPCC 5. Assessment Report published in 2013 for different global warming scenarios. Projections show that for the period 2081-2100 (relatively to 1986-2005), the global mean elevation may range from 40 to 63 cm depending upon the warming scenario, with an uncertainty of ±15 cm due to model imperfection.High regional variability will be superimposed on the global mean rise. In a final section,we briefly discuss expected coastal impacts of sea level rise over the next decades. (authors)

  10. Initial assessment and management of the newborn.

    Science.gov (United States)

    Gooding, Julie R; McClead, Richard E

    2015-04-01

    This article summarizes the initial assessment of normal newborns and describes a few of the common variations that may occur. These variations require a pediatric provider to reassure anxious new parents and provide follow-up communication with the subsequent primary care provider. PMID:25836702

  11. SYSTEM OF GENERALIZED VECTOR VARIATIONAL INEQUALITIES

    Institute of Scientific and Technical Information of China (English)

    Fang Yaping; Huang Nanjing

    2005-01-01

    In this paper, the authors introduce and study system of generalized vector variational inequalities. Under suitable conditions, the existence of solutions for system of generalized vector variational inequalities is presented by Kakutani-Fan-Glicksberg fixed point theorem.

  12. Origins of variation in conducted vasomotor responses

    DEFF Research Database (Denmark)

    Hald, Bjørn Olav; Welsh, Donald G.; Holstein-Rathlou, Niels-Henrik;

    2015-01-01

    variation. Using a computational approach that allows for introduction of structural and electrophysiological heterogeneity, we systematically tested variations in both arteriolar electrophysiology and modes of stimuli. Within the same vessel, our simulations show that conduction efficacy is influenced by...

  13. Racial variations in obstetric practice.

    Science.gov (United States)

    Cauchi, M N

    1986-05-01

    This study involves a retrospective analysis of 453 pregnant persons, with the aim of comparing certain disorders of pregnancy as well as infant and placental parameters in various racial groups within the same community. Significant variations were seen in the mean age of the patients, age at first pregnancy, frequency distribution of first pregnancy, infant weight as well as gravida: parity ratio. There was a 3-fold increase in incidence of preeclampsia in the Australian-born population compared to other racial groups. Mild anaemias (haemoglobin less than 11.5 g/dl) were found in up to 61% of the Australian-born population compared to 32% of the other racial groups; however, more significant degrees of anaemia were more commonly found in certain ethnic groups (e.g. Greek 16%, Italian 15%, Australian-born 6%). These studies emphasize that overall incidence studies in a polyglot population can have very limited meaning, and that greater attention must be paid to the actual racial variations within a population. PMID:3464247

  14. On polar daily geomagnetic variation

    Directory of Open Access Journals (Sweden)

    Paola De Michelis

    2015-11-01

    Full Text Available The aim of this work is to investigate the nature of the daily magnetic field perturbations produced by ionospheric and magnetospheric currents at high latitudes. We analyse the hourly means of the X and Y geomagnetic field components recorded by a meridian chain of permanent geomagnetic observatories in the polar region of the Northern Hemisphere during a period of four years (1995-1998 around the solar minimum. We apply a mathematical method, known as natural orthogonal component (NOC, which is capable of characterizing the dominant modes of the geomagnetic field daily variability through a set of empirical orthogonal functions (EOFs. Using the first two modes we reconstruct a two-dimensional equivalent current representation of the ionospheric electric currents, which contribute substantially to the geomagnetic daily variations. The obtained current structures resemble the equivalent current patterns of DP2 and DP1. We characterize these currents by studying their evolution with the geomagnetic activity level and by analysing their dependence on the interplanetary magnetic field. The obtained results support the idea of a coexistence of two main processes during all analysed period although one of them, the directly driven process, represents the dominant component of the geomagnetic daily variation.

  15. Green mathematics: Benefits of including biological variation in your data analysis

    Directory of Open Access Journals (Sweden)

    L.M.M TIJSKENS

    2015-11-01

    Full Text Available Biological variation is omnipresent in nature. It contains useful information that is neglected by the usually applied statistical procedures. To extract this information special procedures have to be applied. Biological variation is seen in properties (e.g. size, colour, firmness, but the underlying issue is almost always to the variation in development or maturity in a batch of individuals generated by small scale environmental differences. The principles of assessing biological variation in batches of individuals are explained without putting emphasis on mathematical details. Obtained explained parts increase from about 60 to 80 % for the usual approach to 95 when the biological variation is taken into account. When technical variation or measuring error is small even 99 % can be achieved. The benefit of the presented technology is highlighted based on a number of already published studies covering the colour of apples during growth and storage and the firmness of cut tomatoes during storage

  16. Cytoplasmic genetic variation and extensive cytonuclear interactions influence natural variation in the metabolome

    DEFF Research Database (Denmark)

    Joseph, Bindu; Corwin, Jason A.; Li, Baohua;

    2013-01-01

    affects phenotypic variation. This showed that the cytoplasmic variation had effects similar to, if not larger than, the largest individual nuclear locus. Inclusion of cytoplasmic variation into the genetic model greatly increased the explained phenotypic variation. Cytoplasmic genetic variation was a...... central hub in the epistatic network controlling the plant metabolome. This epistatic influence manifested such that the cytoplasmic background could alter or hide pairwise epistasis between nuclear loci. Thus, cytoplasmic genetic variation plays a central role in controlling natural variation in...... metabolomic networks. This suggests that cytoplasmic genomes must be included in any future analysis of natural variation....

  17. Variations of images to increase their visibility

    OpenAIRE

    Sparavigna, Amelia Carolina

    2012-01-01

    The calculus of variations applied to the image processing requires some numerical models able to perform the variations of images and the extremization of appropriate actions. To produce the variations of images, there are several possibilities based on the brightness maps. Before a numerical model, I propose an experimental approach, based on a tool of Gimp, GNU Image Manipulation Program, in order to visualize how the image variations can be. After the discussion of this tool, which is abl...

  18. Quantum Annealing for Variational Bayes Inference

    OpenAIRE

    Sato, Issei; Kurihara, Kenichi; Tanaka, Shu; Nakagawa, Hiroshi; Miyashita, Seiji

    2014-01-01

    This paper presents studies on a deterministic annealing algorithm based on quantum annealing for variational Bayes (QAVB) inference, which can be seen as an extension of the simulated annealing for variational Bayes (SAVB) inference. QAVB is as easy as SAVB to implement. Experiments revealed QAVB finds a better local optimum than SAVB in terms of the variational free energy in latent Dirichlet allocation (LDA).

  19. Importance of Local Structural Variations on Recrystallization

    DEFF Research Database (Denmark)

    Juul Jensen, Dorte; Lin, Fengxiang; Zhang, Yubin; Zhang, Y.H.

    2013-01-01

    Effects of local variations in the deformation microstructure on subsequent recrystallization are discussed and illustrated by three examples. The three examples consider local variations on different length scales and are: 1. Effects of local variations in the deformation microstructure on the f...

  20. Clinical assessment of osteoarthritis of the knee.

    OpenAIRE

    Cushnaghan, J; Cooper, C; Dieppe, P; Kirwan, J; McAlindon, T; McCrae, F

    1990-01-01

    The repeatability of physical signs used to assess osteoarthritis of the knee has not been systematically examined. The within and between observer variation of 10 commonly used physical signs to determine osteoarthritis of the knee has been assessed here. The results obtained show variation in the repeatability of these signs. For those examining the tibiofemoral joints the repeatability was greater than for those examining the patellofemoral joint. It would therefore seem vital to take note...

  1. Weekly Variations in Phytoplankton Structure of a Harbour in Mersin Bay (north-eastern Mediterranean)

    OpenAIRE

    EKER, Elif; KIDEYS, Ahmet Erkan

    2000-01-01

    Weekly variations in the phytoplankton composition of a harbour in Mersin Bay were studied with two methods: filtration for the assessment of >55 mm phytoplankton from July 1995 to June 1997; and sedimentation for the assessment of all phytoplankton (both>55 mm and

  2. Non-differentiable variational principles

    Science.gov (United States)

    Cresson, Jacky

    2005-07-01

    We develop a calculus of variations for functionals which are defined on a set of non-differentiable curves. We first extend the classical differential calculus in a quantum calculus, which allows us to define a complex operator, called the scale derivative, which is the non-differentiable analogue of the classical derivative. We then define the notion of extremals for our functionals and obtain a characterization in term of a generalized Euler-Lagrange equation. We finally prove that solutions of the Schrödinger equation can be obtained as extremals of a non-differentiable variational principle, leading to an extended Hamilton's principle of least action for quantum mechanics. We compare this approach with the scale relativity theory of Nottale, which assumes a fractal structure of space-time.Résumé (Principes variationnels non différentiable). Nous développons un calcul des variations pour des fonctionnelles définies sur un ensemble de courbes non différentiables. Pour cela, nous étendons le calcul différentiel classique, en calcul appelé calcul quantique, qui nous permet de définir un opérateur à valeur complexes, appelé dérivée d'échelle, qui est l'analogue non différentiable de la dérivée usuelle. On définit alors la notion d'extremale pour ces fonctionnelles pour lesquelles nous obtenons une caractérisation via une équation d'Euler-Lagrange généralisée. On prouve enfin que les solutions de l'équation de Schrödinger peuvent s'obtenir comme solution d'un problème variationnel non différentiable, étendant ainsi le principe de moindre action de Hamilton au cadre de la mécanique quantique. On discute enfin la connexion entre ce travail et la théorie de la relativité d'échelle développée par Nottale, et qui suppose une structure fractale de l'espace-temps.

  3. Pain Assessment

    Science.gov (United States)

    Introduction Types of Pain Pain Assessment Pain Treatments Integrative Pain Therapy Pain Management Recommendations References September 04, 2016 Pain Assessment Effective pain management begins with a comprehensive ...

  4. Variation of the latissimus dorsi

    Directory of Open Access Journals (Sweden)

    Ishani P Shah

    2014-01-01

    Full Text Available A typical muscle variation of latissimus dorsi - the axillary arch is represented by the muscular or fibromuscular slip detached from the anteroinferior border of the musculus latissimus dorsi passing over the axilla under the axillary fascia crossing the medial side of the brachial plexus to continue as a septum intermusculare mediale brachii distally to the medial epicondyle of humerus. The full extent of the muscle is rarely present. Slips of muscle extend from the latissimus dorsi at the inferior angle of scapula to insert into pectoralis major (Langer, coracobrachilis, biceps or coracoid process forming what is described as a common variant - the muscular axillary arch. We report three cases of variants of latissimus dorsi, one of which has not been reported in the literature before.

  5. Reasoning about Variation: Student Voice

    Directory of Open Access Journals (Sweden)

    Jackie Reid

    2007-10-01

    Full Text Available This paper reports one recent study that was part of a project investigating tertiary students’ understanding of variation. These students completed a questionnaire prior to, and at the end of, an introductory statistics course and this paper focuses on interviews of selected students designed to determine whether more information could have been gathered about the students’ reasoning. Clarification during interviews reinforced researcher interpretation of responses. Prompting assisted students to develop better quality responses but probing was mostly useful for assisting students to re-express reasoning already presented. Cognitive conflict situations proved challenging. The diversity of activities identified by students as assisting the development of their understanding provides a challenge for educators in planning teaching sequences. Both educators and researchers need to listen to students to better understand the development of reasoning.

  6. Equilibrium models and variational inequalities

    CERN Document Server

    Konnov, Igor

    2007-01-01

    The concept of equilibrium plays a central role in various applied sciences, such as physics (especially, mechanics), economics, engineering, transportation, sociology, chemistry, biology and other fields. If one can formulate the equilibrium problem in the form of a mathematical model, solutions of the corresponding problem can be used for forecasting the future behavior of very complex systems and, also, for correcting the the current state of the system under control. This book presents a unifying look on different equilibrium concepts in economics, including several models from related sciences.- Presents a unifying look on different equilibrium concepts and also the present state of investigations in this field- Describes static and dynamic input-output models, Walras, Cassel-Wald, spatial price, auction market, oligopolistic equilibrium models, transportation and migration equilibrium models- Covers the basics of theory and solution methods both for the complementarity and variational inequality probl...

  7. Variational Principle for Planetary Interiors

    CERN Document Server

    Zeng, Li

    2016-01-01

    In the past few years, the number of confirmed planets has grown above 2000. It is clear that they represent a diversity of structures not seen in our own solar system. In addition to very detailed interior modeling, it is valuable to have a simple analytical framework for describing planetary structures. Variational principle is a fundamental principle in physics, entailing that a physical system follows the trajectory which minimizes its action. It is alternative to the differential equation formulation of a physical system. Applying this principle to planetary interior can beautifully summarize the set of differential equations into one, which provides us some insight into the problem. From it, a universal mass-radius relation, an estimate of error propagation from equation of state to mass-radius relation, and a form of virial theorem applicable to planetary interiors are derived.

  8. Variational Approach and Deformed Derivatives

    CERN Document Server

    Weberszpil, José

    2015-01-01

    Recently, we have demonstrated that there exists a possible relationship between q-deformed algebras in two different contexts of Statistical Mechanics, namely, the Tsallis' framework and the Kaniadakis' scenario, with a local form of fractional-derivative operators for fractal media, the so-called Hausdorff derivatives, mapped into a continuous medium with a fractal measure. Here, in this paper, we present an extension of the traditional calculus of variations for systems containing deformed-derivatives embedded into the Lagrangian and the Lagrangian densities for classical and field systems. The results extend the classical Euler-Lagrange equations and the Hamiltonian formalism. The resulting dynamical equations seem to be compatible with those found in the literature, specially with mass-dependent and with nonlinear equations for systems in classical and quantum mechanics. Examples are presented to illustrate applications of the formulation. Also, the conserved Nether current, are worked out.

  9. Some Variations on Maxwell's Equations

    CERN Document Server

    Ascoli, G A; Ascoli, Giorgio A.; Goldin, Gerald A.

    2006-01-01

    In the first sections of this article, we discuss two variations on Maxwell's equations that have been introduced in earlier work---a class of nonlinear Maxwell theories with well-defined Galilean limits (and correspondingly generalized Yang-Mills equations), and a linear modification motivated by the coupling of the electromagnetic potential with a certain nonlinear Schroedinger equation. In the final section, revisiting an old idea of Lorentz, we write Maxwell's equations for a theory in which the electrostatic force of repulsion between like charges differs fundamentally in magnitude from the electrostatic force of attraction between unlike charges. We elaborate on Lorentz' description by means of electric and magnetic field strengths, whose governing equations separate into two fully relativistic Maxwell systems---one describing ordinary electromagnetism, and the other describing a universally attractive or repulsive long-range force. If such a force cannot be ruled out {\\it a priori\\/} by known physical ...

  10. Fisher Algorithm: Variations And Applications

    Directory of Open Access Journals (Sweden)

    Adegoke

    2013-12-01

    Full Text Available This paper examines Fisherface (Linear Discriminant Analysis methods, its different modifications as applied to feature extraction in face recognition. Researchers showed that Fisher algorithm, though it performs better than PCA, Eigenface and some other fundamental methods, computational complexity, enormous hardware resources usage are inhibitors to its implementation. Different versions or adaptations of Fisher algorithm had been developed, and applied to face recognition and validated using some of the available public face databases. If fisher algorithm and its various variations had so marvelously helped in face recognition, application of this effective dimensionality reduction method can be applied to research area of iris recognition system. This will in return enhance performance of biometric systems in its application to computer security and surveillance.

  11. Flux Variation of Cosmic Muons

    CERN Document Server

    Ramesh, Nepal; Martin, Clayton; Bachri, Abdel

    2012-01-01

    In the current paper, we analyzed the variation of cosmic radiation flux with elevation, time of the year and ambient temperature with the help of a portable cosmic muon detector, the construction of which was completed by a team from Southern Arkansas University (SAU) at Lawrence Berkeley National Laboratory (LBNL). Cosmic muons and gamma rays traverse two synchronized scintillators connected to two photomultiplier tubes (PMT) via light guides, and generate electronic pulses which we counted using a Data Acquisition Board (DAQ). Because muons are the product of collisions between high-energy cosmic rays and atmospheric nuclei, and therefore shower onto earth, the scintillators were arranged horizontally for detection. The elevation measurements were recorded at different locations, starting from 60 feet below sea-level at the Underground Radiation Counting Laboratory at Johnson Space Center, TX, to 4200 feet at Mt. Hamilton, CA. Intermediate locations included sea-level Galveston Bay, TX, and Mt. Magazine, A...

  12. Variational approach and deformed derivatives

    Science.gov (United States)

    Weberszpil, J.; Helayël-Neto, J. A.

    2016-05-01

    Recently, we have demonstrated that there exists a possible relationship between q-deformed algebras in two different contexts of Statistical Mechanics, namely, the Tsallis' framework and the Kaniadakis' scenario, with a local form of fractional-derivative operators for fractal media, the so-called Hausdorff derivatives, mapped into a continuous medium with a fractal measure. Here, in this paper, we present an extension of the traditional calculus of variations for systems containing deformed-derivatives embedded into the Lagrangian and the Lagrangian densities for classical and field systems. The results extend the classical Euler-Lagrange equations and the Hamiltonian formalism. The resulting dynamical equations seem to be compatible with those found in the literature, specially with mass-dependent and with nonlinear equations for systems in classical and quantum mechanics. Examples are presented to illustrate applications of the formulation. Also, the conserved ​Noether current is worked out.

  13. Turbidity variations at Hanford since July 1974

    International Nuclear Information System (INIS)

    Spectral turbidity coefficients derived from multiwavelength sunphotometer measurements obtained from July 1974 to December 1976 have been analyzed for seasonal and weekly variations. Weak biannual variations in turbidity are apparent in the data. Day-to-day variations, however, can be much larger than the coefficients for the fitted biannual terms. Consequently, it now appears that observed variations in turbidity at Hanford are related to the synoptic meteorology with a smaller, superimposed seasonality of dust and smoke sources. Turbidity variations are also independent of the day of the week

  14. Some Variational Principles for Coupled Thermoelasticity

    Directory of Open Access Journals (Sweden)

    Francesco Marotti de Sciarra

    2013-01-01

    Full Text Available The nonlinear thermoelasticity of type II proposed by Green and Naghdi is considered. The thermoelastic structural model is formulated in a quasistatic range, and the related thermoelastic variational formulation in the complete set of state variables is recovered. Hence a consistent framework to derive all the variational formulations with different combinations of the state variables is provided, and a family of mixed variational formulations, with different combinations of state variables, is provided starting from the general variational formulation. A uniqueness condition is provided on the basis of a suitable variational formulation.

  15. Variational methods for field theories

    International Nuclear Information System (INIS)

    Four field theory models are studied: Periodic Quantum Electrodynamics (PQED) in (2 + 1) dimensions, free scalar field theory in (1 + 1) dimensions, the Quantum XY model in (1 + 1) dimensions, and the (1 + 1) dimensional Ising model in a transverse magnetic field. The last three parts deal exclusively with variational methods; the PQED part involves mainly the path-integral approach. The PQED calculation results in a better understanding of the connection between electric confinement through monopole screening, and confinement through tunneling between degenerate vacua. This includes a better quantitative agreement for the string tensions in the two approaches. Free field theory is used as a laboratory for a new variational blocking-truncation approximation, in which the high-frequency modes in a block are truncated to wave functions that depend on the slower background modes (Boron-Oppenheimer approximation). This ''adiabatic truncation'' method gives very accurate results for ground-state energy density and correlation functions. Various adiabatic schemes, with one variable kept per site and then two variables per site, are used. For the XY model, several trial wave functions for the ground state are explored, with an emphasis on the periodic Gaussian. A connection is established with the vortex Coulomb gas of the Euclidean path integral approach. The approximations used are taken from the realms of statistical mechanics (mean field approximation, transfer-matrix methods) and of quantum mechanics (iterative blocking schemes). In developing blocking schemes based on continuous variables, problems due to the periodicity of the model were solved. Our results exhibit an order-disorder phase transition. The transfer-matrix method is used to find a good (non-blocking) trial ground state for the Ising model in a transverse magnetic field in (1 + 1) dimensions

  16. Assessment of Attention in Preschoolers

    OpenAIRE

    Mahone, E.M.; Schneider, H.E.

    2012-01-01

    In the past two decades, there has been an increased interest in the assessment and treatment of preschool children presenting with concerns about attention problems. This article reviews the research and clinical literature involving assessment of attention and related skills in the preschool years. While inattention among preschoolers is common, symptoms alone do not necessarily indicate a disorder, and most often represent a normal variation in typical preschool child development. Thus, ac...

  17. Assessing English Learners' Progress: Longitudinal Invariance of a Standards-Based Classroom Assessment of English Proficiency

    Science.gov (United States)

    Llosa, Lorena

    2012-01-01

    Assessing and monitoring student progress is becoming increasingly important in classrooms and for accountability purposes. Yet, in order to interpret changes in assessment results from one year to the next as reflecting differences in underlying ability rather than as variations in the measurement, the assessments used should be measuring the…

  18. Environmental variation, stochastic extinction, and competitive coexistence.

    Science.gov (United States)

    Adler, Peter B; Drake, John M

    2008-11-01

    Understanding how environmental fluctuations affect population persistence is essential for predicting the ecological impacts of expected future increases in climate variability. However, two bodies of theory make opposite predictions about the effect of environmental variation on persistence. Single-species theory, common in conservation biology and population viability analyses, suggests that environmental variation increases the risk of stochastic extinction. By contrast, coexistence theory has shown that environmental variation can buffer inferior competitors against competitive exclusion through a storage effect. We reconcile these two perspectives by showing that in the presence of demographic stochasticity, environmental variation can increase the chance of extinction while simultaneously stabilizing coexistence. Our stochastic simulations of a two-species storage effect model reveal a unimodal relationship between environmental variation and coexistence time, implying maximum coexistence at intermediate levels of environmental variation. The unimodal pattern reflects the fact that the stabilizing influence of the storage effect accumulates rapidly at low levels of environmental variation, whereas the risk of extinction due to the combined effects of environmental variation and demographic stochasticity increases most rapidly at higher levels of variation. Future increases in environmental variation could either increase or decrease an inferior competitor's expected persistence time, depending on the distance between the present level of environmental variation and the optimal level anticipated by this theory. PMID:18817458

  19. Response variation in a batch of TLDS

    International Nuclear Information System (INIS)

    Full text: At Royal Perth Hospital, LiF thermoluminescent dosimeter rods (TLDs) are handled in batches of 50. Rods in each batch are always annealed together to ensure the same thermal history and an individual batch is used with the same type and energy of radiation. A subset of a batch is used for calibration purposes by exposing them to a range of known doses and their output is used to calculate the dose received by other rods used for a dose measurement. Variation in TLD response is addressed by calculating 95% certainty levels from the calibration rods and applying this to the dose measurement rods. This approach relies on the sensitivity of rods within each batch being similar. This work investigates the validity of this assumption and considers possible benefits of applying individual rod sensitivities. The variation in response of TLD rods was assessed using 25 TLD-100 rods (Harshaw/Bicron) which were uniformly exposed to 1 Gy using 6 MeV photons in a linear accelerator on 5 separate occasions. Rods were read with a Harshaw 5500 reader. During the read process the Harshaw reader periodically checks for noise and PMT gain drift and the data were corrected for these parameters. Replicate exposure data were analysed using 1-way Analysis of Variance (ANOVA) to determine whether the between rod variations were significantly different to the variations within a single rod. A batch of 50 rods was also exposed on three occasions using the above technique. Individual TLD rod sensitivity values were determined using the rod responses from 2 exposures and these values were applied to correct charges on a rod-by-rod basis for the third exposure. ANOVA results on the 5 exposures of 25 rods showed the variance between rods was significantly greater than the within rod variance (p < 0.001). The precision of an individual rod was estimated to have a standard deviation of 2.8%. This suggests that the 95% confidence limits for repeated measurements using the same dose and

  20. Accommodating variation: dialects, idiolects, and speech processing.

    Science.gov (United States)

    Kraljic, Tanya; Brennan, Susan E; Samuel, Arthur G

    2008-04-01

    Listeners are faced with enormous variation in pronunciation, yet they rarely have difficulty understanding speech. Although much research has been devoted to figuring out how listeners deal with variability, virtually none (outside of sociolinguistics) has focused on the source of the variation itself. The current experiments explore whether different kinds of variation lead to different cognitive and behavioral adjustments. Specifically, we compare adjustments to the same acoustic consequence when it is due to context-independent variation (resulting from articulatory properties unique to a speaker) versus context-conditioned variation (resulting from common articulatory properties of speakers who share a dialect). The contrasting results for these two cases show that the source of a particular acoustic-phonetic variation affects how that variation is handled by the perceptual system. We also show that changes in perceptual representations do not necessarily lead to changes in production. PMID:17803986

  1. Oculometric variations during mind wandering

    OpenAIRE

    Grandchamp, Romain; Braboszcz, Claire; Delorme, Arnaud

    2014-01-01

    A significant body of literature supports the contention that pupil size varies depending on cognitive load, affective state, and level of drowsiness. Here we assessed whether oculometric measures such as gaze position, blink frequency and pupil size were correlated with the occurrence and time course of self-reported mind-wandering episodes. We recorded the pupil size of two subjects engaged in a monotonous breath counting task while keeping their eyes on a fixation cross. This task is condu...

  2. Oculometric variations during mind wandering

    OpenAIRE

    RomainGrandchamp; ArnaudDelorme

    2014-01-01

    A significant body of literature supports the contention that pupil size varies depending on cognitive load, affective state, and level of drowsiness. Here we assessed whether oculometric measures such as gaze position, blink frequency and pupil size were correlated with the occurrence and time course of self-reported mind-wandering episodes. We recorded the pupil size of two subjects engaged in a monotonous breath counting task while keeping their eyes on a fixation cross. Each subject perfo...

  3. Spatial and Temporal Variation in Indicator Microbe Sampling is Influential in Beach Management Decisions

    OpenAIRE

    Enns, Amber A.; Vogel, Laura J.; Abdelzaher, Amir M.; Gabriele, Helena M. Solo; Plano, Lisa R. W.; Gidley, Maribeth L.; Phillips, Matthew C.; Klaus, James S.; Piggot, Alan M.; Feng, Zhixuan; Reniers, Adrianus J.H.M.; Haus, Brian K.; Elmir, Samir M.; Zhang, Yifan; Jimenez, Nasly H.

    2012-01-01

    Fecal indicator microbes such as enterococci are often used to assess potential health risks caused by pathogens at recreational beaches. Microbe levels often vary based on collection time and sampling location. The primary goal of this study was to assess how spatial and temporal variations in sample collection which are driven by environmental parameters impact enterococci measurements and beach management decisions. A secondary goal was to assess whether enterococci levels can be predictiv...

  4. Gorilla genome structural variation reveals evolutionary parallelisms with chimpanzee.

    Science.gov (United States)

    Ventura, Mario; Catacchio, Claudia R; Alkan, Can; Marques-Bonet, Tomas; Sajjadian, Saba; Graves, Tina A; Hormozdiari, Fereydoun; Navarro, Arcadi; Malig, Maika; Baker, Carl; Lee, Choli; Turner, Emily H; Chen, Lin; Kidd, Jeffrey M; Archidiacono, Nicoletta; Shendure, Jay; Wilson, Richard K; Eichler, Evan E

    2011-10-01

    Structural variation has played an important role in the evolutionary restructuring of human and great ape genomes. Recent analyses have suggested that the genomes of chimpanzee and human have been particularly enriched for this form of genetic variation. Here, we set out to assess the extent of structural variation in the gorilla lineage by generating 10-fold genomic sequence coverage from a western lowland gorilla and integrating these data into a physical and cytogenetic framework of structural variation. We discovered and validated over 7665 structural changes within the gorilla lineage, including sequence resolution of inversions, deletions, duplications, and mobile element insertions. A comparison with human and other ape genomes shows that the gorilla genome has been subjected to the highest rate of segmental duplication. We show that both the gorilla and chimpanzee genomes have experienced independent yet convergent patterns of structural mutation that have not occurred in humans, including the formation of subtelomeric heterochromatic caps, the hyperexpansion of segmental duplications, and bursts of retroviral integrations. Our analysis suggests that the chimpanzee and gorilla genomes are structurally more derived than either orangutan or human genomes. PMID:21685127

  5. Past Annual Variations of the Karst Denudation Rates

    CERN Document Server

    Shopov, Y; Tsankov, L T; Marinova, E; Sauro, U; Borsato, A; Cucchi, F; Forti, P; Piccini, L; Ford, D C; Yonge, Chas J

    2009-01-01

    We used the quantitative theory of solubility of karst rocks of Shopov et. al, (1989, 1991a) in dependence of the temperature and other thermodynamic parameters to make reconstructions of past carbonate denudation rates. This theory produced equations assessing the carbonate denudation rates in dependence on the temperature or on the precipitation. We estimated the averaged denudation rate in the region to 14 mm/kyr or 38 t/km2 per year. We used this estimate as starting point and substituted our proxy records of the annual temperature and the annual precipitation in the equations of dependence of karst denudation rate on precipitation and temperature. This way we reconstructed variations of the annual karst denudation rate for the last 280 years in dependence on the annual precipitation and for the last 1250 years in dependence on the temperature. Both reconstructions produce quite reasonable estimate of the variations of carbonate denudation, which is within observed variation of 8- 20 mm/kyr (86% variation...

  6. [Variations of the celiac trunk branches in the fetus].

    Science.gov (United States)

    Bordei, P; Antohe, D S

    2002-09-01

    The study was performed on 60 human foetuses, aged between 4 to 9 months, using as methods dissection and plastic and contrast substances injection. We studied the celiac trunk in what concerns the division into its terminal branches, insisting on the possible morphological variations, some rare collateral branches starting from the common arterial trunk, the dimensional relations between the branches at their origin and the level of the celiac trunk origin from the aorta, in relation with the vertebral column, the diaphragmatic passage of the aorta and with the superior mesenteric artery. We also assessed the dimensional relations (calibers at origin) between the branches of the celiac trunk. Ass possible variations of the division of the celiac trunk, we assessed: gastro-hepatic trunk, with the splenic artery directly from the aorta or from the hepatic artery; gastro-splenic trunk, with the hepatic artery originating from the aorta; hepato-splenic trunk, with origin of the left gastric artery either directly from the aorta or from the hepatic artery. Rare variations: celiaco-mesenteric trunk; two arterial trunks, hepato-splenic and hepato-gastric; separate aortic origin for all three "classic" branches of the celiac trunk; two hepatic arteries, one from the celiac trunk and the other from the aorta or superior mesenteric artery; celiac trunk that divides into several terminal branches; one or two suprarenal arteries originating from the celiac trunk. PMID:12572348

  7. How variation between individuals affects species coexistence.

    Science.gov (United States)

    Hart, Simon P; Schreiber, Sebastian J; Levine, Jonathan M

    2016-08-01

    Although the effects of variation between individuals within species are traditionally ignored in studies of species coexistence, the magnitude of intraspecific variation in nature is forcing ecologists to reconsider. Compelling intuitive arguments suggest that individual variation may provide a previously unrecognised route to diversity maintenance by blurring species-level competitive differences or substituting for species-level niche differences. These arguments, which are motivating a large body of empirical work, have rarely been evaluated with quantitative theory. Here we incorporate intraspecific variation into a common model of competition and identify three pathways by which this variation affects coexistence: (1) changes in competitive dynamics because of nonlinear averaging, (2) changes in species' mean interaction strengths because of variation in underlying traits (also via nonlinear averaging) and (3) effects on stochastic demography. As a consequence of the first two mechanisms, we find that intraspecific variation in competitive ability increases the dominance of superior competitors, and intraspecific niche variation reduces species-level niche differentiation, both of which make coexistence more difficult. In addition, individual variation can exacerbate the effects of demographic stochasticity, and this further destabilises coexistence. Our work provides a theoretical foundation for emerging empirical interests in the effects of intraspecific variation on species diversity. PMID:27250037

  8. Assessing the spatial-temporal variations of heavy metals and analysing source of pollution in Daqing City%大庆市土壤环境质量时空变化特征分析及污染源分析

    Institute of Scientific and Technical Information of China (English)

    胡远东; 宋利芳; 王擎宇; 达良俊

    2013-01-01

    Based on the date of environment monitoring station in the Daqing, we analysis the date from 1996 to 2010 by mathematical analysis, the results have revealed the spatial-temporal variations of heavy metals in Daqing soil. Pollution index (PI) and Nemerow's synthetical pollution indexes (P) were used to assess Daqing soil quality. The results indicated that synthetical pollution indexes in oil development area is highest in the four different zones, ,the next is in oil chemical industry area, and the lowest is in grassland farming area. Selecting As、Cd、Cu、Pd as the evaluation factors. The concentration of Pd is highest, the next one is Cu. In the last fifteen years, the heavy metal concentration in the four different zones overall shows a ascending trend. we measure and analyze the source of the heavy metal pollution, the results showed that ground crude oil didn't pollute the oil ,but drilling fluid makes a great impact on heavy metal pollution.%  以大庆环境监测站提供的数据为依据,通过对大庆市1996~2010年土壤环境质量监测数据的数学分析,揭示了15年间大庆在石油资源开发和快速城市化过程中土壤重金属含量的时空变化特征。采用单项指数法(Pi)和Nemerow的综合污染指数(P)对大庆土壤质量进行评价。结果表明:大庆四个不同功能区(牧业草原区、农业开发区、石油化工区、油田开发区)中油田开发区综合污染指数最高,其次为石油化工区,牧业草原区综合污染指数最低。采用As、Cd、Cu、Pd四种重金属作为主要评价因子,其中对大庆土壤重金属污染贡献值最高的是Pd,其次为Cu。近15年来,四个功能区中的重金属浓度总体均呈上升趋势。另外通过对土壤中重金属来源进行测定和分析,结果显示目前落地原油并未对土壤产生重金属污染,但废钻井液对土壤重金属污染有较大影响。

  9. Genetic background of phenotypic variation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A noteworthy feature of the living world is its bewildering variability. A key issue in several biological disciplines is the achievement of an understanding of the hereditary basis of this variability. Two opposing, but not necessarily irreconcilable conceptions attempt to explain the underlying mechanism. The gene function paradigm postulates that phenotypic variance is generated by the polymorphism in the coding sequences of genes. However, comparisons of a great number of homologous gene and protein sequences have revealed that they predominantly remained functionally conserved even across distantly related phylogenic taxa. Alternatively, the gene regulation paradigm assumes that differences in the cis-regulatory region of genes do account for phenotype variation within species. An extension of this latter concept is that phenotypic variability is generated by the polyrnorphism in the overall gene expression profiles of gene networks.In other words, the activity of a particular gene is a system property determined both by the cis-regulatory sequences of the given genes and by the other genes of a gene network, whose expressions vary among individuals, too. Novel proponents of gene function paradigm claim that functional genetic variance within the coding sequences of regulatory genes is critical for the generation of morphological polymorphism. Note, however, that these developmental genes play direct regulatory roles in the control of gene expression.

  10. Temporal Variations in Jupiter's Atmosphere

    Science.gov (United States)

    Simon-Miller, Amy A.; Chanover, N. J.; Yanamandra-Fisher, P.; Hammel, H. B.; dePater, I.; Noll, K.; Wong, M.; Clarke, J.; Sanchez-Levega, A.; Orton, G. S.; Gonzaga, S.

    2009-01-01

    In recent years, Jupiter has undergone many atmospheric changes from storms turning red to global. cloud upheavals, and most recently, a cornet or asteroid impact. Yet, on top of these seemingly random changes events there are also periodic phenomena, analogous to observed Earth and Saturn atmospheric oscillations. We will present 15 years of Hubble data, from 1994 to 2009, to show how the equatorial tropospheric cloud deck and winds have varied over that time, focusing on the F953N, F41 ON and F255W filters. These filters give leverage on wind speeds plus cloud opacity, cloud height and tropospheric haze thickness, and stratospheric haze, respectively. The wind data consistently show a periodic oscillation near 7-8 S latitude. We will discuss the potential for variations with longitude and cloud height, within the calibration limits of those filters. Finally, we will discuss the role that large atmospheric events, such as the impacts in 1994 and 2009, and the global upheaval of 2007, have on temporal studies, This work was supported by a grant from the NASA Planetary Atmospheres Program. HST observational support was provided by NASA through grants from Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under contract NAS5-26555.

  11. On Quadratic Variation of Martingales

    Indian Academy of Sciences (India)

    Rajeeva L Karandikar; B V Rao

    2014-08-01

    We give a construction of an explicit mapping $$\\Psi: D([0,∞),\\mathbb{R})→ D([0,∞),\\mathbb{R}),$$ where $D([0,∞), \\mathbb{R})$ denotes the class of real valued r.c.l.l. functions on $[0,∞)$ such that for a locally square integrable martingale $(M_t)$ with r.c.l.l. paths, $$\\Psi(M.())=A.()$$ gives the quadratic variation process (written usually as $[M,M]_t$) of $(M_t)$. We also show that this process $(A_t)$ is the unique increasing process $(B_t)$ such that $M_t^2-B_t$ is a local martingale, $B_0=0$ and $$\\mathbb{P}(( B)_t=[( M)_t]^2, 0 < ∞)=1.$$ Apart from elementary properties of martingales, the only result used is the Doob’s maximal inequality. This result can be the starting point of the development of the stochastic integral with respect to r.c.l.l. martingales.

  12. PLURILINGUAL COMPETENCE, STYLES AND VARIATION

    Directory of Open Access Journals (Sweden)

    Jyrki Kalliokoski

    2011-01-01

    Full Text Available The paper explores plurilingual competence in respect to language proficiency, language education and pluri- and multilingualism. The notion of communicative competence was introduced by Hymes (1972 as a reaction to chomskyan view of language as an autonomous system. Hymes’ notion of communicative competence originally included plurilingualism. The concept of communicative competence was quickly adopted to applied linguistics but the idea of a linguistic repertoire consisting of the competencies of linguistic varieties was not imported to SLA or language testing. The Hymesian perspective to plurilingualism as an essential dimension of communicative competence was revived in the Common European Framework (CEFR. However,the practice of applying the CEFR has mostly neglected the dimension on plurilingualism and plurilingual competence. The focus in the use of the CEFR has been on the different areas of language skills within one single language at a time, while the application of plurilingual practices has gained very little attention. The Hymesian notion of communicative competence has lived on in the sociolinguistic research tradition, especially within interactional sociolinguistics. The present paper relates the notion of plurilingual competence to its hymesian origin, to recent trends in plurilingual and pluricultural education, and to the sociolinguistic study of style and linguistic variation in multilingual communities. The article uses Finnish L2 data to show how plurilingual competence is used as an interactional resource.From the perspective of language learning, plurilingual competence enables speakers with different linguistic backgrounds to use their shared linguistic repertoire in order to ensure smooth interaction and achieve mutual understanding.

  13. Assessment of LWR spent fuel disposal options. Volume 2. System definition and assessments. Technical report

    International Nuclear Information System (INIS)

    Volume 2, in addition to introducing and defining the requirements for the study, contains the detailed evaluation of the study cases in each of six assessment areas, and describes and evaluates a number of study variations

  14. Variation of DNA damage levels in peripheral blood mononuclear cells isolated in different laboratories

    DEFF Research Database (Denmark)

    Godschalk, Roger W L; Ersson, Clara; Stępnik, Maciej;

    2014-01-01

    This study investigated the levels of DNA strand breaks and formamidopyrimidine DNA glycosylase (FPG) sensitive sites, as assessed by the comet assay, in peripheral blood mononuclear cells (PBMC) from healthy women from five different countries in Europe. The laboratory in each country (referred to...... as 'centre') collected and cryopreserved PBMC samples from three donors, using a standardised cell isolation protocol. The samples were analysed in 13 different laboratories for DNA damage, which is measured by the comet assay. The study aim was to assess variation in DNA damage in PBMC samples that...... were collected in the same way and processed using the same blood isolation procedure. The inter-laboratory variation was the prominent contributor to the overall variation. The inter-laboratory coefficient of variation decreased for both DNA strand breaks (from 68 to 26%) and FPG sensitive sites (from...

  15. Synchronous Lagrangian variational principles in General Relativity

    CERN Document Server

    Cremaschini, Claudio

    2016-01-01

    The problem of formulating synchronous variational principles in the context of General Relativity is discussed. Based on the analogy with classical relativistic particle dynamics, the existence of variational principles is pointed out in relativistic classical field theory which are either asynchronous or synchronous. The historical Einstein-Hilbert and Palatini variational formulations are found to belong to the first category. Nevertheless, it is shown that an alternative route exists which permits one to cast these principles in terms of equivalent synchronous Lagrangian variational formulations. The advantage is twofold. First, synchronous approaches allow one to overcome the lack of gauge symmetry of the asynchronous principles. Second, the property of manifest covariance of the theory is also restored at all levels, including the symbolic Euler-Lagrange equations, with the variational Lagrangian density being now identified with a $4-$scalar. As an application, a joint synchronous variational principle...

  16. Procedural facade variations from a single layout

    KAUST Repository

    Bao, Fan

    2013-01-01

    We introduce a framework to generate many variations of a facade design that look similar to a given facade layout. Starting from an input image, the facade is hierarchically segmented and labeled with a collection of manual and automatic tools. The user can then model constraints that should be maintained in any variation of the input facade design. Subsequently, facade variations are generated for different facade sizes, where multiple variations can be produced for a certain size. Computing such new facade variations has many unique challenges, and we propose a new algorithm based on interleaving heuristic search and quadratic programming. In contrast to most previous work, we focus on the generation of new design variations and not on the automatic analysis of the input\\'s structure. Adding a modeling step with the user in the loop ensures that our results routinely are of high quality. © 2013 ACM.

  17. Variation in the use of alternative levels of hospital care for newborns in a managed care organization.

    OpenAIRE

    Roblin, D. W.; Richardson, D K; Thomas, E; Fitzgerald, F; Veintimilla, R.; Hulac, P.; Bemis, G.; Leon, L.

    2000-01-01

    OBJECTIVE(S): To assess the extent to which variation in the use of neonatal intensive care resources in a managed care organization is a consequence of variation in neonatal health risks and/or variation in the organization and delivery of medical care to newborns. STUDY DESIGN: Data were collected on a cohort of all births from four sites in Kaiser Permanente by retrospective medical chart abstraction of the birth admission. Likelihood of admission into a neonatal intensive care unit (NICU)...

  18. Sources of Variation in the Age Composition of Sandeel Landings

    DEFF Research Database (Denmark)

    Kvist, Trine; Gislason, Hannes; Thyregod, Poul

    2001-01-01

    determination. Although the variation between ICES statistical rectangles is substantial there is a significant difference between the age composition in the northern and southern part of the North Sea. However, only one of the three finer geographical stratifications proposed to improve the assessment results......The variation of the age composition of the landings of lesser sandeel in the Danish industrial fishery in the North Sea over the period From 1984-1993 is analysed by continuation-ratio logits and generalised linear models. The analysis takes the multinomial characteristics of the age composition......+ sandeel in the samples is significantly lower in the start and end of the fishing season. This suggests that the older sandeel are available to the fishery for a shorter time period that the 1-group. Significant differences are found in the age composition between the four laboratories involved in the age...

  19. Cost variation in diabetes care delivered in English hospitals

    DEFF Research Database (Denmark)

    Kristensen, Troels; Laudicella, Mauro; Ejersted, Charlotte;

    2010-01-01

    . The volume of patients, and the number and diversity of specialties involved in caring for diabetic patients do not explain variation in the cost of treating diabetic patients across hospitals.  Conclusion: Health Resource Groups and diagnostic markers are significant patient-related cost drivers in diabetes......Aims: We analyse the in-hospital costs of diabetic patients admitted to English hospitals and aim to assess what proportions of cost variation are explained by patient and hospital characteristics. Methods: We use Hospital Episode Statistics and reference costs for all patients admitted to diabetes...... care for all English hospitals for the financial year 2005/06. Our sample includes 31,371 patients admitted to 148 hospitals. We apply a multilevel approach. We analyse the relationship between patient costs and patient characteristics. We estimate the average cost of being treated in each hospital...

  20. A variational void coalescence model for ductile metals

    KAUST Repository

    Siddiq, Amir

    2011-08-17

    We present a variational void coalescence model that includes all the essential ingredients of failure in ductile porous metals. The model is an extension of the variational void growth model by Weinberg et al. (Comput Mech 37:142-152, 2006). The extended model contains all the deformation phases in ductile porous materials, i.e. elastic deformation, plastic deformation including deviatoric and volumetric (void growth) plasticity followed by damage initiation and evolution due to void coalescence. Parametric studies have been performed to assess the model\\'s dependence on the different input parameters. The model is then validated against uniaxial loading experiments for different materials. We finally show the model\\'s ability to predict the damage mechanisms and fracture surface profile of a notched round bar under tension as observed in experiments. © Springer-Verlag 2011.

  1. Are solar brightness variations faculae- or spot-dominated?

    CERN Document Server

    Shapiro, A I; Krivova, N A; Yeo, K L; Schmutz, W K

    2016-01-01

    Regular spaceborne measurements have revealed that solar brightness varies on multiple timescales, variations on timescales greater than a day being attributed to surface magnetic field. Independently, ground-based and spaceborne measurements suggest that Sun-like stars show a similar, but significantly broader pattern of photometric variability. To understand whether the broader pattern of stellar variations is consistent with the solar paradigm we assess relative contributions of faculae and spots to solar magnetically-driven brightness variability. We investigate how the solar brightness variability as well as its facular and spot contributions depend on the wavelength, timescale of variability, and position of the observer relative to the ecliptic plane. We perform calculations with the SATIRE model, which returns solar brightness with daily cadence from solar disc area coverages of various magnetic features. Moving the observer away from the ecliptic plane increases the amplitude of 11-year variability a...

  2. Concerning long-term geomagnetic variations and space climatology

    Directory of Open Access Journals (Sweden)

    K.-H. Glassmeier

    2004-11-01

    Full Text Available During geomagnetic polarity transitions the surface magnetic field of the Earth decays to about 25% and less of its present value. This implies a shrinking of the terrestrial magnetosphere and posses the question of whether magnetospheric magnetic field variations scale in the same manner. Furthermore, the geomagnetic main field also controls the magnetospheric magnetic field and space weather conditions. Long-term geomagnetic variations are thus intimately related to space climate. We critically assess existing scaling relations and derive new ones for various magnetospheric parameters. For example, we find that ring current perturbations do not increase with decreasing dipole moment. And we derive a scaling relation for the polar electrojet contribution, indicating a weak increase with increasing internal field. From this we infer that the ratio between external and internal field contributions may be weakly enhanced during polarity transitions. Our scaling relations also provide more insight on the importance of the internal geomagnetic field contribution for space climate.

  3. Genetic variation in bovine milk fat composition

    OpenAIRE

    Stoop, W.M.

    2009-01-01

    In her thesis, Stoop shows that there is considerable genetic variation in milk fat composition, which opens opportunities to improve milk fat composition by selective breeding. Short and medium chain fatty acids had high heritabilities, whereas variation due to herd (mainly feed effects) was moderate. Long chain fatty acids had moderate heritabilities, whereas variation due to herd was high. Several genomic regions (QTL) with effect on short and medium chain, long chain, or both types of fat...

  4. DNA fingerprinting and minisatellite variation of swans

    OpenAIRE

    Meng, Anming

    1990-01-01

    Genetic variation in natural populations of four species of swans (Cygnus bewickii, Cygnus olor, Cygnus buccinator and Cygnus cygnus) has been investigated by examining minisatellite loci using human DNA fingerprinting probes pSPT19.6 and pSPT18.15. It has been found that swan minisatellites are highly variable. However, the degree of variation depends on the population structure and species. Bewick's Swans at Slimbridge have the highest degree of minisatellite variation, Whooper Swans at Cae...

  5. Size variation of fossil rodent populations

    OpenAIRE

    Freudenthal, M.; Cuenca Bescos, G.

    1984-01-01

    Pearson's coefficient of variation is in general not applicable in palaeontology, due to the heterogeneity of samples. The heterogeneity may be due to the mixing of two species, mixture of material from various biotopes, or from a relatively large time span. A new coefficient of variation is proposed, based on the range of the sample. This coefficient may be used to estimate the degree of variation of a sample, and to decide whether it is homogeneous. Its application is tested empirically on ...

  6. Measuring human salivary amylase copy number variation

    OpenAIRE

    Dhar, Sugandha

    2010-01-01

    Copy number variations represent large scale genomic alterations varying from 1kb to 3Mb and are proposed as a driving force for genome evolution and variation. One such locus exhibiting copy number variation and genome evolution is salivary amylase, which is responsible for the digestion of starch in the human parotid glands. It was reported that since human salivary amylase gene (AMY1) copy numbers are correlated positively with protein levels, and also due to the correlation of high gene c...

  7. Varying Alpha: New Constraints from Seasonal Variations

    CERN Document Server

    Barrow, John D

    2008-01-01

    We analyze the constraints obtained from new atomic clock data on the possible time variation of the fine structure `constant' and the electron-proton mass ratio and show how they are strengthened when the seasonal variation of Sun's gravitational field at the Earth's surface is taken into account. We compare these bounds with those obtainable from tests of the Weak Equivalence Principle and high-redshift observations of quasar absorption spectra consistent with time variations in the fine structure constant.

  8. Models of Solar Irradiance Variations: Current Status

    Indian Academy of Sciences (India)

    Natalie A. Krivova; Sami K. Solanki

    2008-03-01

    Regular monitoring of solar irradiance has been carried out since 1978 to show that solar total and spectral irradiance varies at different time scales. Whereas variations on time scales of minutes to hours are due to solar oscillations and granulation, variations on longer time scales are driven by the evolution of the solar surface magnetic field. Here the most recent advances in modelling of solar irradiance variations on time scales longer than a day are briefly reviewed.

  9. Variational Inequalities in Critical-State Problems

    OpenAIRE

    Prigozhin, Leonid

    2004-01-01

    Similar evolutionary variational inequalities appear as convenient formulations for continuous quasistationary models for sandpile growth, formation of a network of lakes and rivers, magnetization of type-II superconductors, and elastoplastic deformations. We outline the main steps of such models derivation and try to clarify the origin of this similarity. New dual variational formulations, analogous to mixed variational inequalities in plasticity, are derived for sandpiles and superconductors.

  10. Diurnal Variations in Human Pulmonary Function

    OpenAIRE

    Medarov, Boris I.; Pavlov, Valentin A.; Rossoff, Leonard

    2008-01-01

    Pulmonary function has circadian modulations. Variations in human pulmonary function during the daytime hours (diurnal variations) remain to be well characterized. Discerning these variations will contribute to better understanding the relationship between biorhythms and lung physiology and to improving clinical management of pulmonary diseases. The aim of this study was to determine the magnitude of pulmonary function variability during the usual daytime hours in a population of patients ref...

  11. A Paradigm for Eliciting Story Variation

    OpenAIRE

    Fisseni, Bernhard; Lawrence, Faith

    2013-01-01

    The understanding of story variation, whether motivated by cultural currents or other factors, is important for applications of formal models of narrative such as story generation or story retrieval. We present the first stage of an experiment to elicit natural narrative variation data suitable for evaluation with respect to story similarity, to qualitative and quantitative analysis of story variation, and also for data processing. We also present few prelimary results from the first stage of...

  12. Simplified Variational Principles for Barotropic Magnetohydrodynamics

    OpenAIRE

    Yahalom, Asher; Lynden-Bell, Donald

    2006-01-01

    Variational principles for magnetohydrodynamics were introduced by previous authors both in Lagrangian and Eulerian form. In this paper we introduce simpler Eulerian variational principles from which all the relevant equations of barotropic magnetohydrodynamics can be derived. The variational principle is given in terms of six independent functions for non-stationary barotropic flows and three independent functions for stationary barotropic flows. This is less then the seven variables which a...

  13. Morphometric variation among the Central Indian populations

    OpenAIRE

    Gautam, Rajesh K.; Dipak K. Adak,; Pal, M.; P. Bharati

    2013-01-01

    Data on 8 anthropometric characters of 6663 adult males belonging to 22 caste groups, distributed in 38 districts of Central India were taken for present investigation, to study the morphometric variation. Cephalic index, nasal Index, Generalized Mahalanobis distances and its size and shape components were computed and dendrograms were drawn. Comparison of coefficient of variations shows that there exists variation in nasal breadth, nasal length, weight and hence in nasal index. But no marked...

  14. Spectrum characteristics of geoelectric field variation

    Institute of Scientific and Technical Information of China (English)

    YE Qing; DU Xue-bin; ZHOU Ke-chang; LI Ning; MA Zhan-hu

    2007-01-01

    The spectrum characteristics of geoelectric diurnal variation and geoelectric storm have been identified by maximum entropy method, based on geoelectric data from seven stations in the Chinese mainland, including Jiayuguan, Changli and Chongming. The study shows that, in geoelectric diurnal variation, the amplitude of the 12 h semidiurnal wave is the largest, followed in turn by the 24~25 h diurnal wave and the 8 h periodic wave; Geoelectric storm usually occurs in a large-scale space, whose spectrum values are higher than those of geoelectric diurnal variation by 2~3 orders of magnitude. A preliminary interpretation is presented for the generative mechanism of predominant waves in geoelectric field variation.

  15. Genetic variations in multiple myeloma I

    DEFF Research Database (Denmark)

    Vangsted, A.; Klausen, T.W.; Vogel, Ulla Birgitte

    2012-01-01

    variability in a population. The complex interplay between environment and genes for the development of cancer may therefore be influenced by genetic variations. A genetic variation may change the function of the gene, and if the genetic variation is associated with the risk of disease, that particular gene......Few risk factors have been established for the plasma cell disorder multiple myeloma, but some of these like African American ethnicity and a family history of B-cell lymphoproliferative diseases suggest a genetic component for the disease. Genetic variation represents the genetic basis of...

  16. Extensive Variation in Chromatin States Across Humans

    KAUST Repository

    Kasowski, M.

    2013-10-17

    The majority of disease-associated variants lie outside protein-coding regions, suggesting a link between variation in regulatory regions and disease predisposition. We studied differences in chromatin states using five histone modifications, cohesin, and CTCF in lymphoblastoid lines from 19 individuals of diverse ancestry. We found extensive signal variation in regulatory regions, which often switch between active and repressed states across individuals. Enhancer activity is particularly diverse among individuals, whereas gene expression remains relatively stable. Chromatin variability shows genetic inheritance in trios, correlates with genetic variation and population divergence, and is associated with disruptions of transcription factor binding motifs. Overall, our results provide insights into chromatin variation among humans.

  17. Factors influencing variation in dentist service rates.

    Science.gov (United States)

    Grembowski, D; Milgrom, P; Fiset, L

    1990-01-01

    In the previous article, we calculated dentist service rates for 200 general dentists based on a homogeneous, well-educated, upper-middle-class population of patients. Wide variations in the rates were detected. In this analysis, factors influencing variation in the rates were identified. Variation in rates for categories of dental services was explained by practice characteristics, patient exposure to fluoridated water supplies, and non-price competition in the dental market. Rates were greatest in large, busy practices in markets with high fees. Older practices consistently had lower rates across services. As a whole, these variables explained between 5 and 30 percent of the variation in the rates. PMID:2118182

  18. Antimicrobial price variation: Conundrum of medical profession!

    Directory of Open Access Journals (Sweden)

    Rataboli P

    2007-01-01

    Full Text Available Pharmacoeconomics plays a pivotal role in clinical practice. High medicine prices can adversely affect a patient′s finances and compliance. The Indian pharmaceutical industry has become a cornucopia of medicines with wide variation in prices for the same medicine marketed under different brand names. Price list of available antimicrobial brands was procured from a commercial drug directory. Average price of widely prescribed oral antimicrobials was found and price variation between different brands was calculated. The variation in medicine prices was found to be from 95% lower to more than 350% higher than the average price. Implications of price variation in clinical practice are discussed and remedial measures suggested.

  19. Mitochondrial DNA variation analysis in cervical cancer.

    Science.gov (United States)

    Kabekkodu, Shama Prasada; Bhat, Samatha; Mascarenhas, Roshan; Mallya, Sandeep; Bhat, Manoj; Pandey, Deeksha; Kushtagi, Pralhad; Thangaraj, Kumarasamy; Gopinath, P M; Satyamoorthy, Kapaettu

    2014-05-01

    This study was undertaken to investigate the mitochondrial DNA (mtDNA) variation in non-malignant and malignant cervical tissue samples. We have identified 229 and 739 variations non-malignant and malignant tissues respectively distributed over 321 locations in the D-loop (50 in non-malignant and 166 in malignant; 216 variations), coding region (139 in non-malignant and 455 in malignant; 594 variations) tRNA and rRNA genes (39 in non-malignant and 119 in malignant; 158 variations). Besides, 77 novel and 34 various other disease associated variations were identified in non-malignant and malignant samples. A total of 236 tumor specific variations in 201 locations representing 30.1% in D-loop, 59.3% in coding regions and 10.6% in RNA genes were also identified. Our study shows that D loop (in 67 locations) is highly altered followed by ND5 (35 locations) region. Moreover, mtDNA alterations were significantly higher in malignant samples by two tailed Fisher's exact test (P≤0.05) with decreased mtDNA copy numbers. Bioinformatic analysis of 59 non-synonymous changes predicted several variations as damaging leading to decreased stability of the proteins. Taken together, mtDNA is highly altered in cervical cancer and functional studies are needed to be investigated to understand the consequence of these variations in cervical carcinogenesis and their potential application as biomarkers. PMID:23851045

  20. Study on Somaclonal Variation of Spring Wheat

    Institute of Scientific and Technical Information of China (English)

    JIANG Shu-mei; HU Shang-lian; LI Wen-xiong

    2004-01-01

    Somaclonal variation of calli and regenerated plants of spring wheat ware detected by using technique RAPD in the study. Calli at different culture stages and regenerated plants derived from young spikes and immature embryos were used as materials. Molecular variation could be reflected from electrophoresis patternof RAPD fragments at different culture stage in calli, and in regenerated plants derived from different explants, even no phenotype variations were found. Somaclonal variation in calli and in regenerated plants appeared regularly: A higher frequency of variation in hybrids F2 was detected than that of the cultivar that is stable genetically. High variation frequency of RAPD fragments appeared in calli when cultured 75 days. The identical variations of RAPD fragments were observed in calli and in the regenerated plants induced from different genotype or explants. The variation frequency detected is higher in regenerated plants than that of in calli. RAPD could be applied easily and simply to determine variation in level of DNA at each stage cultured in vitro.

  1. Parkinson's disease and mitochondrial gene variations

    DEFF Research Database (Denmark)

    Andalib, Sasan; Vafaee, Manouchehr Seyedi; Gjedde, Albert

    2014-01-01

    Parkinson's disease (PD) is a common disorder of the central nervous system in the elderly. The pathogenesis of PD is a complex process, with genetics as an important contributing factor. This factor may stem from mitochondrial gene variations and mutations as well as from nuclear gene variations...... and mutations. More recently, a particular role of mitochondrial dysfunction has been suggested, arising from mitochondrial DNA variations or acquired mutations in PD pathogenesis. The present review summarizes and weighs the evidence in support of mitochondrial DNA (mtDNA) variations as important...

  2. Duality in optimization and variational inequalities

    CERN Document Server

    Goh, Cj

    2001-01-01

    This comprehensive volume covers a wide range of duality topics ranging from simple ideas in network flows to complex issues in non-convex optimization and multicriteria problems. In addition, it examines duality in the context of variational inequalities and vector variational inequalities, as generalizations to optimization. Duality in Optimization and Variational Inequalities is intended for researchers and practitioners of optimization with the aim of enhancing their understanding of duality. It provides a wider appreciation of optimality conditions in various scenarios and under different assumptions. It will enable the reader to use duality to devise more effective computational methods, and to aid more meaningful interpretation of optimization and variational inequality problems.

  3. Variation in prostate cancer treatment associated with population density of the county of residence

    OpenAIRE

    Cary, C; Odisho, AY; Cooperberg, MR

    2016-01-01

    © 2016 Macmillan Publishers Limited Background:We sought to assess variation in the primary treatment of prostate cancer by examining the effect of population density of the county of residence on treatment for clinically localized prostate cancer and quantify variation in primary treatment attributable to the county and state level.Methods:A total 138 226 men with clinically localized prostate cancer in the Surveillance, Epidemiology and End Result (SEER) database in 2005 through 2008 were a...

  4. Unacceptable variation in the core diameters of some AO type cancellous screws.

    OpenAIRE

    Lloyd, M N H

    1989-01-01

    This study assesses the variability in core diameter of a series of cancellous screws and its effect on torque strength. Analysis of a series of 107 cancellous screws revealed a wide variation of the core diameters in our sample. Tests to evaluate the effect of this variation showed that torsional strength is directly proportional to the cube of the radius of the core; a 30% reduction in radius resulting in a 70% loss in torsional strength. Conclusions drawn from this experimental data indica...

  5. Prevalence and variation of sesamoid bones in the hand: a multi-center radiographic study

    OpenAIRE

    Chen, Wei; Cheng, Jiaxiang; Sun, Ran; Zhang, Zekun; Zhu, Yanbin; Ipaktchi, Kyros; Zhang, Yingze

    2015-01-01

    There is rare studies with regard to sesamoid bone variations of the hand in addition to its prevalence and distribution. This study aims to assess both the prevalence and variation of sesamoid bones of the hand. A retrospective review of posteroanterior (PA) and oblique radiographs of 436 left and 414 right hands of 850 adult patients obtained from four hospitals was performed. All X-ray films were examined independently for existing sesamoid bones. The presence of sesamoid bones was confirm...

  6. Intraspecific variation in the advertisement call of the cloud-forest frog Eleutherodactylus glamyrus (Anura: Eleutherodactylidae).

    OpenAIRE

    Rodríguez, A; de la Nuez, D.; Alonso, R.

    2010-01-01

    We analyzed variation in the advertisement calls among three localities of Eleutherodactylus glamyrus, a frog endemic to the Sierra Maestra mountains in Eastern Cuba. We assessed the levels of withinmale variation of each call property and the influence of temperature and size of calling male on acoustical features. The typical single-note advertisement call of the species was described using temporal and spectral parameters. Rise time and frequency modulation were highly variable...

  7. Understanding Variation in Treatment Effects in Education Impact Evaluations: An Overview of Quantitative Methods.

    OpenAIRE

    Peter Z. Schochet; Mike Puma; John Deke

    2014-01-01

    Variation in treatment effects has important implications for education practice—and for facilitating the most efficient use of limited resources—by informing decisions about how best to target interventions and how to improve the design or implementation of interventions. Understanding variation in effects is also critical to assessing how study findings may be generalized to other education environments. A new report, co-authored by Mathematica's education experts, can help researchers ...

  8. Measuring Regional and District Variations in the Incidence of Pregnancy-induced Hypertension (PIH) in Ghana : Challenges, Opportunities and Implications for Maternal and Newborn Health Policy and Programs

    NARCIS (Netherlands)

    Antwi, Edward; Klipstein-Grobusch, Kerstin; Asare, Gloria Quansah; Koram, Kwadwo A; Grobbee, Diederick; Agyepong, Irene Akua

    2016-01-01

    OBJECTIVES: The objectives were to assess the quality of health management information system (HMIS) data needed for assessment of local area variation in pregnancy induced hypertension (PIH) incidence and to describe district and regional variations in PIH incidence. METHODS: A retrospective review

  9. Temporal variations in rainwater methanol

    Science.gov (United States)

    Felix, J. D.; Jones, S. B.; Avery, G. B.; Willey, J. D.; Mead, R. N.; Kieber, R. J.

    2014-10-01

    This work reports the first comprehensive analysis of methanol concentrations in rainwater. Methanol concentrations measured in 49 rain events collected between 28 August 2007 and 10 July 2008 in Wilmington, NC, USA, ranged from below the detection limit of 6 nM to 9.3 μM with a volume-weighted average concentration of 1 ± 0.2 μM. Methanol concentrations in rainwater were up to ~200 times greater than concentrations reported previously in marine waters, indicating wet deposition as a potentially significant source of methanol to marine waters. Assuming that these methanol concentrations are an appropriate proxy for global methanol rainwater concentrations, the global methanol wet deposition sink is estimated as 20 Tg yr-1, which implies that previous methanol budgets underestimate removal by precipitation. Methanol concentrations in rainwater did not correlate significantly with H+, NO3-, and NSS, which suggests that the dominant source of the alcohol to rainwater is not anthropogenic. However, methanol concentrations were strongly correlated with acetaldehyde, which has a primarily biogenic input. The methanol volume-weighted concentration during the summer (2.7 ± 0.9 μM) was ~3 times that of the winter (0.9 ± 0.2 μM), further promoting biogenic emissions as the primary cause of temporal variations of methanol concentrations. Methanol concentrations peaked in rainwater collected during the time period 12 p.m.-6 p.m. Peaking during this period of optimal sunlight implies a possible relationship with photochemical methanol production, but there are also increases in biogenic activity during this time period. Rain events with terrestrial origin had greater concentrations than those of marine origin, demonstrating the significance of the continental source of methanol in rainwater.

  10. Howard Hughes Medical Institute dose assessment survey

    International Nuclear Information System (INIS)

    Biomedical science researchers often express frustration that health physics practices vary widely between individual institutions. A survey examining both internal and external dose assessment practices was devised and mailed to fifty institutions supporting biomedical science research. The results indicate that health physics dose assessment practices and policies are highly variable. Factors which may contribute to the degree of variation are discussed. 2 tabs

  11. Stress responsiveness predicts individual variation in mate selectivity.

    Science.gov (United States)

    Vitousek, Maren N; Romero, L Michael

    2013-06-15

    Steroid hormones, including glucocorticoids, mediate a variety of behavioral and physiological processes. Circulating hormone concentrations vary substantially within populations, and although hormone titers predict reproductive success in several species, little is known about how individual variation in circulating hormone concentrations is linked with most reproductive behaviors in free-living organisms. Mate choice is an important and often costly component of reproduction that also varies substantially within populations. We examined whether energetically costly mate selection behavior in female Galápagos marine iguanas (Amblyrhynchus cristatus) was associated with individual variation in the concentrations of hormones previously shown to differ between reproductive and non-reproductive females during the breeding season (corticosterone and testosterone). Stress-induced corticosterone levels - which are suppressed in female marine iguanas during reproduction - were individually repeatable throughout the seven-week breeding period. Mate selectivity was strongly predicted by individual variation in stress-induced corticosterone: reproductive females that secreted less corticosterone in response to a standardized stressor assessed more displaying males. Neither baseline corticosterone nor testosterone predicted variation in mate selectivity. Scaled body mass was not significantly associated with mate selectivity, but females that began the breeding period in lower body condition showed a trend towards being less selective about potential mates. These results provide the first evidence that individual variation in the corticosterone stress response is associated with how selective females are in their choice of a mate, an important contributor to fitness in many species. Future research is needed to determine the functional basis of this association, and whether transient acute increases in circulating corticosterone directly mediate mate choice behaviors. PMID

  12. Regional variations in the growth of Saudi children and adolescents

    International Nuclear Information System (INIS)

    No previous study has provided a detailed description of regional variations of growth within the various regions of Saudi Arabia. Thus, we sought to demonstrate differences in growth of children and adolescents in different regions. The 2005 Saudi reference was based on a cross-sectional representative sample of the Saudi population of healthy children and adolescents from birth to 18 years of age. Body measurements of the length, stature, weight, head circumference and calculation of the BMI were performed according to standard recommendations. Percentile construction and smoothing were performed using the LMS (lambda, mu and sigma) methodology, followed by transformation of all individual measurements into standard deviation scores. Factors such as weight for age, height for age, weight for height, and head circumference for children from birth to 3 years, stature for age, head circumference and body mass index for children between 2-18 years of age were assessed. Subsequently, variations in growth between the three main regions in the north, southwest, and center of Saudi Arabia were calculated, with the Bonferroni: method used to assess the significance of differences between regions. There were significant differences in growth between regions that varied according to age, gender, growth parameter and region. The highest variation was found between children and adolescents of the southwestern region and those of the other two regions The regression lines for all growth parameters in children <3 years of age were significantly different from one region to another reaching - 0.65 standard deviation scores for the southwestern regions ( P =.001). However, the difference between the northern and central regions were not significant for the head circumference and for weight for length. For older children and adolescents a significant difference was found in all parameters except between the northern and central regions in BMI in girls and head circumference in

  13. Diagnostic quality and observer variation in radiographic diagnoses of approximal caries

    International Nuclear Information System (INIS)

    The aim of the study was to compare observer variations, observer strategy, and diagnostic quality with regard to radiographic caries diagnoses made at different depth levels. Qualitative assessment of approximal carious lesions on the basis of radiographs were made for sound (n=28) and carious (n=123) lesions by seven dentists. The inter- and intra-observer variations were lowest when lesions were diagnosed as being in the outermost parts of the teeth. The frequency of false positive scores was lower when dentin was examined as compared with enamel. The quality of radiographic diagnoses showed small variations (p>0.05) when different levels of pulpal depths were interpreted

  14. Texture variations suppress suprathreshold brightness and colour variations.

    Science.gov (United States)

    Schofield, Andrew J; Kingdom, Frederick A A

    2014-01-01

    Discriminating material changes from illumination changes is a key function of early vision. Luminance cues are ambiguous in this regard, but can be disambiguated by co-incident changes in colour and texture. Thus, colour and texture are likely to be given greater prominence than luminance for object segmentation, and better segmentation should in turn produce stronger grouping. We sought to measure the relative strengths of combined luminance, colour and texture contrast using a suprathreshhold, psychophysical grouping task. Stimuli comprised diagonal grids of circular patches bordered by a thin black line and contained combinations of luminance decrements with either violet, red, or texture increments. There were two tasks. In the Separate task the different cues were presented separately in a two-interval design, and participants indicated which interval contained the stronger orientation structure. In the Combined task the cues were combined to produce competing orientation structure in a single image. Participants had to indicate which orientation, and therefore which cue was dominant. Thus we established the relative grouping strength of each cue pair presented separately, and compared this to their relative grouping strength when combined. In this way we observed suprathreshold interactions between cues and were able to assess cue dominance at ecologically relevant signal levels. Participants required significantly more luminance and colour compared to texture contrast in the Combined compared to Separate conditions (contrast ratios differed by about 0.1 log units), showing that suprathreshold texture dominates colour and luminance when the different cues are presented in combination. PMID:25502555

  15. Texture variations suppress suprathreshold brightness and colour variations.

    Directory of Open Access Journals (Sweden)

    Andrew J Schofield

    Full Text Available Discriminating material changes from illumination changes is a key function of early vision. Luminance cues are ambiguous in this regard, but can be disambiguated by co-incident changes in colour and texture. Thus, colour and texture are likely to be given greater prominence than luminance for object segmentation, and better segmentation should in turn produce stronger grouping. We sought to measure the relative strengths of combined luminance, colour and texture contrast using a suprathreshhold, psychophysical grouping task. Stimuli comprised diagonal grids of circular patches bordered by a thin black line and contained combinations of luminance decrements with either violet, red, or texture increments. There were two tasks. In the Separate task the different cues were presented separately in a two-interval design, and participants indicated which interval contained the stronger orientation structure. In the Combined task the cues were combined to produce competing orientation structure in a single image. Participants had to indicate which orientation, and therefore which cue was dominant. Thus we established the relative grouping strength of each cue pair presented separately, and compared this to their relative grouping strength when combined. In this way we observed suprathreshold interactions between cues and were able to assess cue dominance at ecologically relevant signal levels. Participants required significantly more luminance and colour compared to texture contrast in the Combined compared to Separate conditions (contrast ratios differed by about 0.1 log units, showing that suprathreshold texture dominates colour and luminance when the different cues are presented in combination.

  16. Variational data assimilation using targetted random walks

    KAUST Repository

    Cotter, S. L.

    2011-02-15

    The variational approach to data assimilation is a widely used methodology for both online prediction and for reanalysis. In either of these scenarios, it can be important to assess uncertainties in the assimilated state. Ideally, it is desirable to have complete information concerning the Bayesian posterior distribution for unknown state given data. We show that complete computational probing of this posterior distribution is now within the reach in the offline situation. We introduce a Markov chain-Monte Carlo (MCMC) method which enables us to directly sample from the Bayesian posterior distribution on the unknown functions of interest given observations. Since we are aware that these methods are currently too computationally expensive to consider using in an online filtering scenario, we frame this in the context of offline reanalysis. Using a simple random walk-type MCMC method, we are able to characterize the posterior distribution using only evaluations of the forward model of the problem, and of the model and data mismatch. No adjoint model is required for the method we use; however, more sophisticated MCMC methods are available which exploit derivative information. For simplicity of exposition, we consider the problem of assimilating data, either Eulerian or Lagrangian, into a low Reynolds number flow in a two-dimensional periodic geometry. We will show that in many cases it is possible to recover the initial condition and model error (which we describe as unknown forcing to the model) from data, and that with increasing amounts of informative data, the uncertainty in our estimations reduces. © 2011 John Wiley & Sons, Ltd.

  17. Spatial and Temporal Dependence of Temperature Variations Induced by Atmospheric Pressure Variations in Shallow Underground Cavities

    Energy Technology Data Exchange (ETDEWEB)

    Perrier, F.; Le Mouel, J.L. [Inst Phys Globe, Equipe Geomagnetisme, F-75005 Paris (France); Univ Paris Diderot, UMR7154, F-75005 Paris (France); Richon, P. [CEA Bruyeres-le-Chatel, DIF, 91 (France); Richon, P. [Inst Phys Globe, Equipe Geol Syst Volcan, UMR7154, F-75005 Paris (France)

    2010-07-01

    Pressure-induced temperature (PIT) variations are systematically observed in the atmosphere of underground cavities. Such PIT variations are due to the compressibility of the air, damped by heat exchange with the rock surface. It is important to characterize such processes for numerous applications, such as the preservation of painted caves or the assessment of the long-term stability of underground laboratories and underground waste repositories. In this paper we thoroughly study the spatio-temporal dependence of the PIT response versus frequency using vertical and horizontal profiles of temperature installed in an abandoned underground quarry located in Vincennes, near Paris. The PIT response varies from about 20 * 10{sup -3} C hPa{sup -1} at a frequency of 2 * 10{sup -4} Hz to 2-3 * 10{sup -3} C hPa{sup -1} at a frequency of one cycle per day. An analytical expression based on a simple heat exchange model accounts for the observed features of the PIT response and allows for correcting the measured time series, having standard deviations of about 10{sup -2} C, to residual variations with a standard deviation of about 2 * 10{sup -3} C. However, a frequency-dependent attenuation of the response, corresponding to a reduction in amplitude with a factor varying from 2 to 3, is observed near the walls. This effect is not included in the simple analytical expression, but it can be accounted for by a one-dimensional differential equation, solved numerically, where temperature variations in the atmosphere are damped by an effective radiative coupling with the rock surface, complemented by a diffusive coupling near the walls. The TIP response is observed to remain stable over several years, but a large transient enhancement of about a factor of two is observed near the roof at one location from July to October 2005. In a cavity located below the Paris Observatory, an additional contribution is identified in the PIT response function versus frequency for frequencies smaller

  18. Site assessment

    DEFF Research Database (Denmark)

    Vesth, Allan; Gómez Arranz, Paula

    This report describes the site assessment of given position in a given site, for a wind turbine with a well-defined hub height and rotor diameter. The analysis is carried out in accordance to IEC 61400-12-1 [1], and both an obstacle assessment and a terrain assessment are performed....

  19. Anatomy, Medical Education, and Human Ancestral Variation

    Science.gov (United States)

    Strkalj, Goran; Spocter, Muhammad A.; Wilkinson, A. Tracey

    2011-01-01

    It is argued in this article that the human body both in health and disease cannot be fully understood without adequately accounting for the different levels of human variation. The article focuses on variation due to ancestry, arguing that the inclusion of information pertaining to ancestry in human anatomy teaching materials and courses should…

  20. Hamiltonian and Variational Linear Distributed Systems

    NARCIS (Netherlands)

    Rapisarda, P.; Trentelman, H.L.

    2002-01-01

    We use the formalism of bilinear- and quadratic differential forms in order to study Hamiltonian and variational linear distributed systems. It was shown that a system described by ordinary linear constant-coefficient differential equations is Hamiltonian if and only if it is variational. In this pa

  1. Item versus System Learning: Explaining Free Variation.

    Science.gov (United States)

    Ellis, Rod

    1999-01-01

    Provides an explanation for the existence of free variation in learner language. Argues that interlanguage is best conceptualized as sets of loose lexical networks that are gradually reorganized into a system or systems. Free variation arises when learners add items to those they have already acquired and before they analyze these items and…

  2. Size variation of fossil rodent populations

    NARCIS (Netherlands)

    Freudenthal, M.; Cuenca Bescos, G.

    1984-01-01

    Pearson's coefficient of variation is in general not applicable in palaeontology, due to the heterogeneity of samples. The heterogeneity may be due to the mixing of two species, mixture of material from various biotopes, or from a relatively large time span. A new coefficient of variation is propose

  3. Size variation in Middle Pleistocene humans.

    Science.gov (United States)

    Arsuaga, J L; Carretero, J M; Lorenzo, C; Gracia, A; Martínez, I; Bermúdez de Castro, J M; Carbonell, E

    1997-08-22

    It has been suggested that European Middle Pleistocene humans, Neandertals, and prehistoric modern humans had a greater sexual dimorphism than modern humans. Analysis of body size variation and cranial capacity variation in the large sample from the Sima de los Huesos site in Spain showed instead that the sexual dimorphism is comparable in Middle Pleistocene and modern populations. PMID:9262474

  4. Varying Constants: Constraints from Seasonal Variations

    CERN Document Server

    Shaw, Douglas J

    2010-01-01

    We analyse the constraints obtained from new atomic clock data on the possible time variation of the fine structure `constant' and the electron-proton mass ratio and show how they are strengthened when the seasonal variation of Sun's gravitational field at the Earth's surface is taken into account.

  5. Stochastic variational approach to minimum uncertainty states

    International Nuclear Information System (INIS)

    We introduce a new variational characterization of Gaussian diffusion processes as minimum uncertainty states. We then define a variational method constrained by kinematics of diffusions and Schroedinger dynamics to seek states of local minimum uncertainty for general non-harmonic potentials. (author)

  6. A Fitting Robot for Variational Analysis

    CERN Document Server

    Cais, A Ó; Mahbub, S; Williams, T

    2008-01-01

    We develop a robot algorithm to maximise the number of distinct states reliably extracted from correlator data using the variational analysis method. The robot explores the variational parameter space and attempts to remove, as far as possible, the human element from the fitting of the subsequent orthogonalised data.

  7. Exploring Duopoly Markets with Conjectural Variations

    Science.gov (United States)

    Julien, Ludovic A.; Musy, Olivier; Saïdi, Aurélien W.

    2014-01-01

    In this article, the authors investigate competitive firm behaviors in a two-firm environment assuming linear cost and demand functions. By introducing conjectural variations, they capture the different market structures as specific configurations of a more general model. Conjectural variations are based on the assumption that each firm believes…

  8. Stochastic Variational Approach to Minimum Uncertainty States

    OpenAIRE

    Illuminati, F.; Viola, L.

    1995-01-01

    We introduce a new variational characterization of Gaussian diffusion processes as minimum uncertainty states. We then define a variational method constrained by kinematics of diffusions and Schr\\"{o}dinger dynamics to seek states of local minimum uncertainty for general non-harmonic potentials.

  9. Stochastic variational approach to minimum uncertainty states

    CERN Document Server

    Illuminati, F; Illuminati, F; Viola, L

    1995-01-01

    We introduce a new variational characterization of Gaussian diffusion processes as minimum uncertainty states. We then define a variational method constrained by kinematics of diffusions and Schr\\"{o}dinger dynamics to seek states of local minimum uncertainty for general non-harmonic potentials.

  10. Stochastic variational approach to minimum uncertainty states

    Energy Technology Data Exchange (ETDEWEB)

    Illuminati, F.; Viola, L. [Dipartimento di Fisica, Padova Univ. (Italy)

    1995-05-21

    We introduce a new variational characterization of Gaussian diffusion processes as minimum uncertainty states. We then define a variational method constrained by kinematics of diffusions and Schroedinger dynamics to seek states of local minimum uncertainty for general non-harmonic potentials. (author)

  11. Variation in animal response to different toxicants

    Science.gov (United States)

    Hilado, C. J.; Cumming, H. J.

    1977-01-01

    The variation in response of different lots of male Swiss albino mice to pyrolysis effluents from surgical cotton and from bisphenol A polycarbonate, and to pure carbon monoxide, is discussed. The variation appeared to be less with the pyrolysis gases from polycarbonate than with pure carbon monoxide.

  12. Closed orbit response to quadrupole strength variation

    Energy Technology Data Exchange (ETDEWEB)

    Wolski, Andrzej; Zimmermann, Frank

    2004-01-20

    We derive two formulae relating the variation in closed orbit in a storage ring to variations in quadrupole strength, neglecting nonlinear and dispersive effects. These formulae correct results previously reported [1,2,3]. We compare the results of the formulae applied to the ATF with simulations using MAD, and consider their application to beam-based alignment.

  13. Caval variations in neurologically diseased patients

    International Nuclear Information System (INIS)

    The import of the cavum variation and its prevalence rate in healthy individuals is still not clear, likewise in neurologically diseased patients. To evaluate the frequency and pattern of caval variations in neurologically diseased patients. The presence or absence of the cavum septum pellucidum (CSP), cavum vergae (CV), or cavum velum interpositum (CVI) was reviewed from successive cranial computerized tomography (CT) images of patients who were aged 6 months and above. Two hundred and seventeen cranial CT images were reviewed. At least a cavum variation was noted in 130 (59.9%) of the CT scan images reviewed. The CV, CVI, and CSP were noted in 86 (39.6%), 53 (24.4%), and 50 images (23%), respectively. Caval multiplicity was noted in 102 patients (47%). There was no significant difference in the rate of occurrence of cavum variations in patients with congenital brain diseases and acquired brain conditions (P = 0.484), neither was there a significant difference in the frequency of cavum variation in children aged older than 6 months compared to adults (P = 0.101). Cava variations are relatively common in neurological brain diseases. Patients with congenital brain diseases did not have a higher frequency of cava variation when compared with those that had acquired lesions. The most common type of cavum variation noted in this study was the vergae variety, while the CSP is the rarest

  14. Cosmic Time Variation of the Gravitational Constant

    CERN Document Server

    Tomaschitz, R

    2000-01-01

    A pre-relativistic cosmological approach to electromagnetism and gravitation is explored that leads to a cosmic time variation of the fundamental constants. Space itself is supposed to have physical substance, which manifests by its permeability. The scale factors of the permeability tensor induce a time variation of the fundamental constants. Atomic radii, periods, and energy levels scale in cosmic time, which results in dispersionless redshifts without invoking a space expansion. Hubble constant and deceleration parameter are reviewed in this context. The time variation of the gravitational constant at the present epoch can be expressed in terms of these quantities. This provides a completely new way to restrain the deceleration parameter from laboratory bounds on the time variation of the gravitational constant. This variation also affects the redshift dependence of angular diameters and the surface brightness, and we study in some detail the redshift scaling of the linear sizes of radio sources. The effec...

  15. Variation Tolerant On-Chip Interconnects

    CERN Document Server

    Nigussie, Ethiopia Enideg

    2012-01-01

    This book presents design techniques, analysis and implementation of high performance and power efficient, variation tolerant on-chip interconnects.  Given the design paradigm shift to multi-core, interconnect-centric designs and the increase in sources of variability and their impact in sub-100nm technologies, this book will be an invaluable reference for anyone concerned with the design of next generation, high-performance electronics systems. Provides comprehensive, circuit-level explanation of high-performance, energy-efficient, variation-tolerant on-chip interconnect; Describes design techniques to mitigate problems caused by variation; Includes techniques for design and implementation of self-timed on-chip interconnect, delay variation insensitive communication protocols, high speed signaling techniques and circuits, bit-width independent completion detection and process, voltage and temperature variation tolerance.                          

  16. Variations of images to increase their visibility

    CERN Document Server

    Sparavigna, Amelia Carolina

    2012-01-01

    The calculus of variations applied to the image processing requires some numerical models able to perform the variations of images and the extremization of appropriate actions. To produce the variations of images, there are several possibilities based on the brightness maps. Before a numerical model, I propose an experimental approach, based on a tool of Gimp, GNU Image Manipulation Program, in order to visualize how the image variations can be. After the discussion of this tool, which is able to strongly increase the visibility of images, the variations and a possible functional for the visibility are proposed in the framework of a numerical model. The visibility functional is analogous to the fringe visibility of the optical interference.

  17. Variational inequalities and frictional contact problems

    CERN Document Server

    Capatina, Anca

    2014-01-01

    Variational Inequalities and Frictional Contact Problems contains a carefully selected collection of results on elliptic and evolutionary quasi-variational inequalities including existence, uniqueness, regularity, dual formulations, numerical approximations and error estimates ones. By using a wide range of methods and arguments, the results are presented in a constructive way, with clarity and well justified proofs. This approach makes the subjects accessible to mathematicians and applied mathematicians. Moreover, this part of the book can be used as an excellent background for the investigation of more general classes of variational inequalities. The abstract variational inequalities considered in this book cover the variational formulations of many static and quasi-static contact problems. Based on these abstract results, in the last part of the book, certain static and quasi-static frictional contact problems in elasticity are studied in an almost exhaustive way. The readers will find a systematic and uni...

  18. Prediction of interannual climate variations

    International Nuclear Information System (INIS)

    It has been known for some time that the behavior of the short-term fluctuations of the earth's atmosphere resembles that of a chaotic non-linear dynamical system, and that the day-to-day weather cannot be predicted beyond a few weeks. However, it has also been found that the interactions of the atmosphere with the underlying oceans and the land surfaces can produce fluctuations whose time scales are much longer than the limits of deterministic prediction of weather. It is, therefore, natural to ask whether it is possible that the seasonal and longer time averages of climate fluctuations can be predicted with sufficient skill to be beneficial for social and economic applications, even though the details of day-to-day weather cannot be predicted beyond a few weeks. The main objective of the workshop was to address this question by assessing the current state of knowledge on predictability of seasonal and interannual climate variability and to investigate various possibilities for its prediction. (orig./KW)

  19. Peer Assessment without Assessment Criteria

    Science.gov (United States)

    Jones, Ian; Alcock, Lara

    2014-01-01

    Peer assessment typically requires students to judge peers' work against assessment criteria. We tested an alternative approach in which students judged pairs of scripts against one another in the absence of assessment criteria. First year mathematics undergraduates (N?=?194) sat a written test on conceptual understanding of multivariable…

  20. Variation in mammographic appearance between projections of small breast cancers compared with radial scars

    International Nuclear Information System (INIS)

    Full text: Aims: The study aims to assess variation in appearance between mammographic projections (conspicuity variation) for invasive breast cancers (IBCs) compared with respect to breast density and the proportion of cases detected by one of two readers and required a third (consensus) read. Materials and methods: The study was approved by the Breast Screen Victoria research committee. Mammograms of 75 randomly selected invasive breast cancers, with histological diameter :510 mm (IBC), were mixed with 67 consecutively detected RS, all from a double-reading population-based breast cancer screening programme. On blinded review, these 142 lesions were classified for mammographic findings and assessed for marked or minor conspicuity variation between views. We assessed the associations between lesion type, lesion spicules and centres, breast density, conspicuity variation and proportion detected by one reader only. Results: Marked conspicuity variation was common, but not statistically different for BC and RS (64% vs. 66%, X2 = 0.8, P = 0.04). Conspicuity variation did not correlate with spiculation type (long, fine or short, broad based) or lesion centres (lucent or dense) (p 2 2.3, P = 0.5; RS, X2 = 0.95, P = 0.6). Density did not vary by lesion type. In the screening programme, 29% of BC (125 of 431) versus 43% of RS (32 of 75) had been detected by one of two readers (X2 2.7, P = 0.098). Conclusions: Two-thirds of small IBCs displayed marked conspicuity variation, similar to RS. Therefore, conspicuity variation does not discriminate between IBC and RS.