Genetic Diversity of Mycobacterium tuberculosis Isolates from Assam, India: Dominance of Beijing Family and Discovery of Two New Clades Related to CAS1_Delhi and EAI Family Based on Spoligotyping and MIRU-VNTR Typing.

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Devi, Kangjam Rekha; Bhutia, Rinchenla; Bhowmick, Shovonlal; Mukherjee, Kaustab; Mahanta, Jagadish; Narain, Kanwar

2015-01-01

Tuberculosis (TB) is one of the major public health concerns in Assam, a remote state located in the northeastern (NE) region of India. The present study was undertaken to explore the circulating genotypes of Mycobacterium tuberculosis complex (MTBC) in this region. A total of 189 MTBC strains were collected from smear positive pulmonary tuberculosis cases from different designated microscopy centres (DMC) from various localities of Assam. All MTBC isolates were cultured on Lowenstein-Jensen (LJ) media and subsequently genotyped using spoligotyping and 24-loci mycobacterial interspersed repetitive units-variable number of tandem repeats (MIRU-VNTR) typing. Spoligotyping of MTBC isolates revealed 89 distinct spoligo patterns. The most dominant MTBC strain belonged to Beijing lineage and was represented by 35.45% (n = 67) of total isolates, followed by MTBC strains belonging to Central Asian-Delhi (CAS/Delhi) lineage and East African Indian (EAI5) lineage. In addition, in the present study 43 unknown spoligo patterns were detected. The discriminatory power of spoligotyping was found to be 0.8637 based on Hunter Gaston Discriminatory Index (HGDI). On the other hand, 24-loci MIRU-VNTR typing revealed that out of total 189 MTBC isolates from Assam 185 (97.9%) isolates had unique MIRU-VNTR profiles and 4 isolates grouped into 2 clusters. Phylogenetic analysis of 67 Beijing isolates based on 24-loci MIRU-VNTR typing revealed that Beijing isolates from Assam represent two major groups, each comprising of several subgroups. Neighbour-Joining (NJ) phylogenetic tree analysis based on combined spoligotyping and 24-loci MIRU-VNTR data of 78 Non-Beijing isolates was carried out for strain lineage identification as implemented by MIRU-VNTRplus database. The important lineages of MTBC identified were CAS/CAS1_Delhi (41.02%, n = 78) and East-African-Indian (EAI, 33.33%). Interestingly, phylogenetic analysis of orphan (23.28%) MTBC spoligotypes revealed that majority of these orphan

Comparison of Variable-Number Tandem-Repeat Markers typing and IS1245 Restriction Fragment Length Polymorphism fingerprinting of Mycobacterium avium subsp. hominissuis from human and porcine origins

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Marttila Harri

2010-03-01

Full Text Available Abstract Background Animal mycobacterioses are regarded as a potential zoonotic risk and cause economical losses world wide. M. avium subsp. hominissuis is a slow-growing subspecies found in mycobacterial infected humans and pigs and therefore rapid and discriminatory typing methods are needed for epidemiological studies. The genetic similarity of M. avium subsp. hominissuis from human and porcine origins using two different typing methods have not been studied earlier. The objective of this study was to compare the IS1245 RFLP pattern and MIRU-VNTR typing to study the genetic relatedness of M. avium strains isolated from slaughter pigs and humans in Finland with regard to public health aspects. Methods A novel PCR-based genotyping method, variable number tandem repeat (VNTR typing of eight mycobacterial interspersed repetitive units (MIRUs, was evaluated for its ability to characterize Finnish Mycobacterium avium subsp. hominissuis strains isolated from pigs (n = 16 and humans (n = 13 and the results were compared with those obtained by the conventional IS1245 RFLP method. Results The MIRU-VNTR results showed a discriminatory index (DI of 0,92 and the IS1245 RFLP resulted in DI 0,98. The combined DI for both methods was 0,98. The MIRU-VNTR test has the advantages of being simple, reproducible, non-subjective, which makes it suitable for large-scale screening of M. avium strains. Conclusions Both typing methods demonstrated a high degree of similarity between the strains of human and porcine origin. The parallel application of the methods adds epidemiological value to the comparison of the strains and their origins. The present approach and results support the hypothesis that there is a common source of M. avium subsp. hominissuis infection for pigs and humans or alternatively one species may be the infective source to the other.

Trends and differences in tuberculosis incidences and clustering among natives in Denmark, Sweden and Finland

DEFF Research Database (Denmark)

Pedersen, M K; Lillebaek, T; Andersen, A B

2018-01-01

among the countries. In addition, for the periods 2012-2013 and 2014-2015, genotyping data were compared. Genotyping was performed using the 24-locus mycobacterial interspersed repetitive unit-variable number of tandem repeat (MIRU-VNTR) method in Denmark and Sweden. For Finland, spoligotyping...... in conjunction with the 15-locus MIRU-VNTR method was used for 2012-2013 and translated into the 24-locus MIRU-VNTR when feasible, and for 2014-2015 only MIRU-VNTR was used. Both incidence trends and molecular epidemiology were assessed for native cases. RESULTS: The average annual rate of change in TB incidence...

Genomic Variability of Mycobacterium tuberculosis Strains of the Euro-American Lineage Based on Large Sequence Deletions and 15-Locus MIRU-VNTR Polymorphism

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Rindi, Laura; Medici, Chiara; Bimbi, Nicola; Buzzigoli, Andrea; Lari, Nicoletta; Garzelli, Carlo

2014-01-01

A sample of 260 Mycobacterium tuberculosis strains assigned to the Euro-American family was studied to identify phylogenetically informative genomic regions of difference (RD). Mutually exclusive deletions of regions RD115, RD122, RD174, RD182, RD183, RD193, RD219, RD726 and RD761 were found in 202 strains; the RDRio deletion was detected exclusively among the RD174-deleted strains. Although certain deletions were found more frequently in certain spoligotype families (i.e., deletion RD115 in T and LAM, RD174 in LAM, RD182 in Haarlem, RD219 in T and RD726 in the “Cameroon” family), the RD-defined sublineages did not specifically match with spoligotype-defined families, thus arguing against the use of spoligotyping for establishing exact phylogenetic relationships between strains. Notably, when tested for katG463/gyrA95 polymorphism, all the RD-defined sublineages belonged to Principal Genotypic Group (PGG) 2, except sublineage RD219 exclusively belonging to PGG3; the 58 Euro-American strains with no deletion were of either PGG2 or 3. A representative sample of 197 isolates was then analyzed by standard 15-locus MIRU-VNTR typing, a suitable approach to independently assess genetic relationships among the strains. Analysis of the MIRU-VNTR typing results by using a minimum spanning tree (MST) and a classical dendrogram showed groupings that were largely concordant with those obtained by RD-based analysis. Isolates of a given RD profile show, in addition to closely related MIRU-VNTR profiles, related spoligotype profiles that can serve as a basis for better spoligotype-based classification. PMID:25197794

Contribution of spoligotyping and MIRU-VNTRs to characterize prevalent Mycobacterium tuberculosis genotypes infecting tuberculosis patients in Morocco.

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Chaoui, Imane; Zozio, Thierry; Lahlou, Ouafae; Sabouni, Radia; Abid, Mohammed; El Aouad, Rajae; Akrim, Mohammed; Amzazi, Said; Rastogi, Nalin; El Mzibri, Mohammed

2014-01-01

In the present study, Mycobacterium tuberculosis complex (MTBC) clinical isolates from culture-positive TB patients in Morocco were studied by spoligotyping and 12-loci MIRU-VNTR typing methods to characterize prevalent genotypes (n = 219 isolates from 208 patients). Spoligotyping resulted in 39 unique patterns and 167 strains in 30 clusters (2-50 strains per cluster). Comparison with international database showed that 29 of 39 unique patterns matched existing shared spoligotype international types (SITs). Nine shared types containing 10 strains were newly created (SIT 2891 to SIT 2899); this led to the description of 69 SITs with 206 strains and two orphan patterns. The most prevalent spoligotype was SIT42 (LAM; n = 50 or 24% of isolates). The repartition of strains according to major MTBC clades was as follows LAM (46.1%)> Haarlem (26%) >ill-defined T superfamily (22.6%) and S clade (0.96%). On the other hand, Beijing, CAS (Central Asian) and EAI (East-African Indian) strains were absent in this setting. Subsequent 12-Loci MIRU typing resulted in a total of 25 SIT/MIT clusters (n = 66 isolates, 2-6 isolates per cluster), with a resulting recent transmission rate of 22.3%. The MIRU-VNTR patterns corresponded to 69 MITs for 138 strains and 46 orphan patterns. The most frequent patterns were MIT43 (n = 8), MIT9 (n = 7) and MIT42 (n = 7). HGDI analysis of the 12 MIRU loci showed that loci 10, 23 and 40 were highly discriminative in our setting. The results also underlined the usefulness of spoligotyping and MIRU-VNTR to detect mixed infections among certain of our TB patients. Globally, the results obtained showed that TB is almost exclusively transmitted in Morocco through evolutionary-modern MTBC lineages belonging to principal genetic groups 2/3 strains (Haarlem, LAM, T), with a high level of biodiversity seen by MIRU typing. This study provides with a 1st global snapshot of MTBC population structure in Morocco, and validates the potential use of spoligotyping in

Rapid clonal analysis of recurrent tuberculosis by direct MIRU-VNTR typing on stored isolates

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de Viedma Darío

2007-07-01

Full Text Available Abstract Background The application of molecular tools to the analysis of tuberculosis has revealed examples of clonal complexity, such as exogenous reinfection, coinfection, microevolution or compartmentalization. The detection of clonal heterogeneity by standard genotyping approaches is laborious and often requires expertise. This restricts the rapid availability of Mycobacterium tuberculosis (MTB genotypes for clinical or therapeutic decision-making. A new PCR-based technique, MIRU-VNTR, has made it possible to genotype MTB in a time frame close to real-time fingerprinting. Our purpose was to evaluate the capacity of this technique to provide clinicians with a rapid discrimination between reactivation and exogenous reinfection and whether MIRU-VNTR makes it possible to obtain data directly from stored MTB isolates from recurrent episodes. Results We detected differences, between the MIRUtypes of recurrent isolates in 38.5% (5/13 of the cases studied. These included cases of i exogenous reinfection, often with more resistant strains, ii likely examples of microevolution, leading to the appearance of new clonal variants and iii a combination of microevolution, coinfection and competition. Conclusion MIRU-VNTR rapidly obtained clinically useful genotyping data in a challenging situation, directly from stored MTB isolates without subculturing them or purifying their DNA. Our results also mean that MIRU-VNTR could be applied for easy, rapid and affordable massive screening of collections of stored MTB isolates, which could establish the real dimension of clonal heterogeneity in MTB infection.

[Discriminatory power of variable number on tandem repeats loci for genotyping Mycobacterium tuberculosis strains in China].

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Chen, H X; Cai, C; Liu, J Y; Zhang, Z G; Yuan, M; Jia, J N; Sun, Z G; Huang, H R; Gao, J M; Li, W M

2017-06-10

Objective: Using the standard genotype method, variable number of tandem repeats (VNTR), we constructed a VNTR database to cover all provinces and proposed a set of optimized VNTR loci combinations for each province, in order to improve the preventive and control programs on tuberculosis, in China. Methods: A total of 15 loci VNTR was used to analyze 4 116 Mycobacterium tuberculosis strains, isolated from national survey of Drug Resistant Tuberculosis, in 2007. Hunter-Gaston Index (HGI) was also used to analyze the discriminatory power of each VNTR site. A set combination of 12-VNTR, 10-VNTR, 8-VNTR and 5-VNTR was respectively constructed for each province, based on 1) epidemic characteristics of M. tuberculosis lineages in China, with high discriminatory power and genetic stability. Results: Through the completed 15 loci VNTR patterns of 3 966 strains under 96.36 % (3 966/4 116) coverage, we found seven high HGI loci (including QUB11b and MIRU26) as well as low stable loci (including QUB26, MIRU16, Mtub21 and QUB11b) in several areas. In all the 31 provinces, we found an optimization VNTR combination as 10-VNTR loci in Inner Mongolia, Chongqing and Heilongjiang, but with 8-VNTR combination shared in other provinces. Conclusions: It is necessary to not only use the VNTR database for tracing the source of infection and cluster of M. tuberculosis in the nation but also using the set of optimized VNTR combinations in monitoring those local epidemics and M. tuberculosis (genetics in local) population.

Determination of circulating Mycobacterium tuberculosis strains and transmission patterns among TB patients in Iran, using 15 loci MIRU-VNTR

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S Zamani

2015-01-01

Conclusions: MIRU-VNTR typing showed a high genetic diversity and suggests the possibility of transmission from Sistan–Baluchestan to other provinces of Iran. This method could be considered a suitable tool for studying the transmission routes of TB and leading to more appropriate measures for TB control. MIRU-VNTR typing leads to a much better understanding of the bacterial population structure and phylogenetic relationships between strains of MTB in different regions of Iran.

Mycobacterial interspersed repetitive-unit-variable-number tandem-repeat (MIRU-VNTR) genotyping of mycobacterium intracellulare for strain comparison with establishment of a PCR-based database.

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Iakhiaeva, Elena; McNulty, Steven; Brown Elliott, Barbara A; Falkinham, Joseph O; Williams, Myra D; Vasireddy, Ravikiran; Wilson, Rebecca W; Turenne, Christine; Wallace, Richard J

2013-02-01

Strain comparison is important to population genetics and to evaluate relapses in patients with Mycobacterium avium complex (MAC) lung disease, but the "gold standard" of pulsed-field gel electrophoresis (PFGE) is time-consuming and complex. We used variable-number tandem repeats (VNTR) for fingerprinting of respiratory isolates of M. intracellulare from patients with underlying bronchiectasis, to establish a nonsequence-based database for population analysis. Different genotypes identified by PFGE underwent species identification using a 16S rRNA gene multiplex PCR. Genotypes of M. intracellulare were confirmed by internal transcribed spacer 1 (ITS1) sequencing and characterized using seven VNTR primers. The pattern of VNTR amplicon sizes and repeat number defined each specific VNTR type. Forty-two VNTR types were identified among 84 genotypes. PFGE revealed most isolates with the same VNTR type to be clonal or exhibit similar grouping of bands. Repetitive sequence-based PCR (rep-PCR) showed minimal pattern diversity between VNTR types compared to PFGE. Fingerprinting of relapse isolates from 31 treated patients using VNTR combined with 16S multiplex PCR unambiguously and reliably distinguished different genotypes from the same patient, with results comparable to those of PFGE. VNTR for strain comparison is easier and faster than PFGE, is as accurate as PFGE, and does not require sequencing. Starting with a collection of 167 M. intracellulare isolates, VNTR distinguished M. intracellulare into 42 clonal groups. Comparison of isolates from different geographic areas, habitats, and clinical settings is now possible.

Mycobacterium tuberculosis Isolates from Single Outpatient Clinic in Panama City Exhibit Wide Genetic Diversity

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Sambrano, Dilcia; Correa, Ricardo; Almengor, Pedro; Domínguez, Amada; Vega, Silvio; Goodridge, Amador

2014-01-01

Understanding Mycobacterium tuberculosis biodiversity and transmission is significant for tuberculosis control. This short report aimed to determine the genetic diversity of M. tuberculosis isolates from an outpatient clinic in Panama City. A total of 62 M. tuberculosis isolates were genotyped by 12 loci mycobacterial interspersed repetitive units-variable number of tandem repeats (MIRU-VNTR) and Spoligotyping. Forty-five (72.6%) of the isolates showed unique MIRU-VNTR genotypes, and 13 (21%) of the isolates were grouped into four clusters. Four isolates showed polyclonal MIRU-VNTR genotypes. The MIRU-VNTR Hunter-Gaston discriminatory index reached 0.988. The Spoligotyping analysis revealed 16 M. tuberculosis families, including Latin American-Mediterranean, Harlem, and Beijing. These findings suggest a wide genetic diversity of M. tuberculosis isolates at one outpatient clinic. A detailed molecular epidemiology survey is now warranted, especially following second massive immigration for local Panama Canal expansion activities. PMID:24865686

MIRU-VNTR genotype diversity and indications of homoplasy in M. avium strains isolated from humans and slaughter pigs in Latvia.

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Kalvisa, Adrija; Tsirogiannis, Constantinos; Silamikelis, Ivars; Skenders, Girts; Broka, Lonija; Zirnitis, Agris; Jansone, Inta; Ranka, Renate

2016-09-01

Diseases which are caused by non-tuberculous mycobacteria (NTM) are an increasing problem in the developed countries. In Latvia, one of the most clinically important members of NTM is Mycobacterium avium (M. avium), an opportunistic pathogen which has been isolated from several lung disease patients and tissue samples of slaughter pigs. This study was designed to characterize the genetic diversity of the M. avium isolates in Latvia and to compare the distribution of genotypic patterns among humans and pigs. Eleven (Hall and Salipante, 2010) clinical M. avium samples, isolated from patients of Center of Tuberculosis and Lung Diseases (years 2003-2010), and 32 isolates from pig necrotic mesenterial lymph nodes in different regions (years 2003-2007) were analyzed. The majority (42 of 43) of samples were identified as M. avium subsp. hominissuis; one porcine isolate belonged to M. avium subsp. avium. MIRU-VNTR genotyping revealed 13 distinct genotypes, among which nine genotype patterns, including M. avium subsp. avium isolate, were newly identified. IS1245 RFLP fingerprinting of 25 M. avium subsp. hominissuis samples yielded 17 different IS1245 RFLP patterns, allowing an efficient discrimination of isolates. Clusters of identical RFLP profiles were observed within host species, geographical locations and time frame of several years. Additional in silico analysis on simulated MIRU-VNTR genotype population datasets showed that the MIRU-VNTR pattern similarity could partly arise due to probabilistic increase of acquiring homoplasy among subpopulations, thus the similar MIRU-VNTR profiles of M. avium strains even in close geographical proximity should be interpreted with caution. Copyright © 2016 Elsevier B.V. All rights reserved.

Automated High-Throughput Genotyping for Study of Global Epidemiology of Mycobacterium tuberculosis Based on Mycobacterial Interspersed Repetitive Units

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Supply, Philip; Lesjean, Sarah; Savine, Evgueni; Kremer, Kristin; van Soolingen, Dick; Locht, Camille

2001-01-01

Large-scale genotyping of Mycobacterium tuberculosis is especially challenging, as the current typing methods are labor-intensive and the results are difficult to compare among laboratories. Here, automated typing based on variable-number tandem repeats (VNTRs) of genetic elements named mycobacterial interspersed repetitive units (MIRUs) in 12 mammalian minisatellite-like loci of M. tuberculosis is presented. This system combines analysis of multiplex PCRs on a fluorescence-based DNA analyzer with computerized automation of the genotyping. Analysis of a blinded reference set of 90 strains from 38 countries (K. Kremer et al., J. Clin. Microbiol. 37:2607–2618, 1999) demonstrated that it is 100% reproducible, sensitive, and specific for M. tuberculosis complex isolates, a performance that has not been achieved by any other typing method tested in the same conditions. MIRU-VNTRs can be used for analysis of the global genetic diversity of M. tuberculosis complex strains at different levels of evolutionary divergence. To fully exploit the portability of this typing system, a website was set up for the analysis of M. tuberculosis MIRU-VNTR genotypes via the Internet. This opens the way for global epidemiological surveillance of tuberculosis and should lead to novel insights into the evolutionary and population genetics of this major pathogen. PMID:11574573

High-resolution minisatellite-based typing as a portable approach to global analysis of Mycobacterium tuberculosis molecular epidemiology

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Mazars, Edith; Lesjean, Sarah; Banuls, Anne-Laure; Gilbert, Michèle; Vincent, Véronique; Gicquel, Brigitte; Tibayrenc, Michel; Locht, Camille; Supply, Philip

2001-01-01

The worldwide threat of tuberculosis to human health emphasizes the need to develop novel approaches to a global epidemiological surveillance. The current standard for Mycobacterium tuberculosis typing based on IS6110 restriction fragment length polymorphism (RFLP) suffers from the difficulty of comparing data between independent laboratories. Here, we propose a high-resolution typing method based on variable number tandem repeats (VNTRs) of genetic elements named mycobacterial interspersed repetitive units (MIRUs) in 12 human minisatellite-like regions of the M. tuberculosis genome. MIRU-VNTR profiles of 72 different M. tuberculosis isolates were established by PCR analysis of all 12 loci. From 2 to 8 MIRU-VNTR alleles were identified in the 12 regions in these strains, which corresponds to a potential of over 16 million different combinations, yielding a resolution power close to that of IS6110-RFLP. All epidemiologically related isolates tested were perfectly clustered by MIRU-VNTR typing, indicating that the stability of these MIRU-VNTRs is adequate to track outbreak episodes. The correlation between genetic relationships inferred from MIRU-VNTR and IS6110-RFLP typing was highly significant. Compared with IS6110-RFLP, high-resolution MIRU-VNTR typing has the considerable advantages of being fast, appropriate for all M. tuberculosis isolates, including strains that have a few IS6110 copies, and permitting easy and rapid comparison of results from independent laboratories. This typing method opens the way to the construction of digital global databases for molecular epidemiology studies of M. tuberculosis. PMID:11172048

Low numbers of repeat units in variable number of tandem repeats (VNTR) regions of white spot syndrome virus are correlated with disease outbreaks.

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Hoa, T T T; Zwart, M P; Phuong, N T; de Jong, M C M; Vlak, J M

2012-11-01

White spot syndrome virus (WSSV) is the most important pathogen in shrimp farming systems worldwide including the Mekong Delta, Vietnam. The genome of WSSV is characterized by the presence of two major 'indel regions' found at ORF14/15 and ORF23/24 (WSSV-Thailand) and three regions with variable number tandem repeats (VNTR) located in ORF75, ORF94 and ORF125. In the current study, we investigated whether or not the number of repeat units in the VNTRs correlates with virus outbreak status and/or shrimp farming practice. We analysed 662 WSSV samples from individual WSSV-infected Penaeus monodon shrimp from 104 ponds collected from two important shrimp farming regions of the Mekong Delta: Ca Mau and Bac Lieu. Using this large data set and statistical analysis, we found that for ORF94 and ORF125, the mean number of repeat units (RUs) in VNTRs was significantly lower in disease outbreak ponds than in non-outbreak ponds. Although a higher mean RU number was observed in the improved-extensive system than in the rice-shrimp or semi-intensive systems, these differences were not significant. VNTR sequences are thus not only useful markers for studying WSSV genotypes and populations, but specific VNTR variants also correlate with disease outbreaks in shrimp farming systems. © 2012 Blackwell Publishing Ltd.

Predominance of Central Asian and European families among Mycobacterium tuberculosis isolates in Kashmir Valley, India.

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Bashir, Gulnaz; Wani, Tehmeena; Sharma, Pragya; Katoch, V M; Lone, Rubina; Shah, Azra; Katoch, Kiran; Kakru, D K; Chauhan, Devendra Singh

2017-10-01

As there are no data available regarding the strains of Mycobacterium tuberculosis circulating in Kashmir Valley, India, the current study aimed at describing the genetic diversity of M. tuberculosis strains in this region, by spoligotyping and 12-locus-based MIRU-VNTR typing (Mycobacterial Interspersed Repetitive Unit-Variable Number Tandem Repeat). Sputa from 207 smear positive cases with newly diagnosed pulmonary tuberculosis were subjected to culture for M. tuberculosis. Eighty-five isolates confirmed as M. tuberculosis were subjected to drug susceptibility testing and molecular typing by spoligotyping and MIRU-VNTRs. Drug susceptibility results of 72 isolates revealed 76.3% as fully sensitive while 5.5% as multidrug resistant (MDR). Spoligotyping of 85 isolates detected 42 spoligotypes with 50 isolates (58.8%) clustered into seven spoligotypes. SIT26/CAS1_Del was the major spoligotype (23, 27%) followed by SIT127/H4 (12, 14.1%); CAS lineage (37.6%) was predominant, followed by Haarlem (25.8%) and ill-defined T clade (23.5%). MIRU-VNTR analysis displayed 82 MIRU patterns from 85 strains, including 3 small clusters and 79 unique. MIRU 26 was found to be the most discriminatory locus. Kashmir Valley has CAS as the predominant lineage of M. tuberculosis similar to the rest of the Indian sub-continent, while it is peculiar in having Euro American lineages such as Haarlem and ill-defined T clade. Copyright © 2017 Tuberculosis Association of India. Published by Elsevier B.V. All rights reserved.

MIRU-VNTR Genotyping of Mycobacterium tuberculosis Strains Using QIAxcel Technology: A Multicentre Evaluation Study.

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Nikolayevskyy, Vladyslav; Trovato, Alberto; Broda, Agnieszka; Borroni, Emanuele; Cirillo, Daniela; Drobniewski, Francis

2016-01-01

Molecular genotyping of M.tuberculosis is an important laboratory tool in the context of emerging drug resistant TB. The standard 24-loci MIRU-VNTR typing includes PCR amplification followed by the detection and sizing of PCR fragments using capillary electrophoresis on automated sequencers or using agarose gels. The QIAxcel Advanced system might offer a cost-effective medium-throughput alternative. Performance characteristics of the QIAxcel Advanced platform for the standard 24 VNTR loci panel was evaluated at two centres on a total of 140 DNA specimens using automated capillary electrophoresis as a reference method. Additionally 4 hypervariable MIRU-VNTR loci were evaluated on 53 crude DNA extracts. The sizing accuracy, interlaboratory reproducibility and overall instrument's performance were assessed during the study. An overall concordance with the reference method was high reaching 98.5% and 97.6% for diluted genomic and crude DNA extracts respectively. 91.4% of all discrepancies were observed in fragments longer than 700bp. The concordance for hypervariable loci was lower except for locus 4120 (96.2%). The interlaboratory reproducibility agreement rates were 98.9% and 91.3% for standard and hypervariable loci, respectively. Overall performance of the QIAxcel platform for M.tuberculosis genotyping using a panel of standard loci is comparable to that of established methods for PCR fragments up to 700bp. Inaccuracies in sizing of longer fragments could be resolved through using in-house size markers or introduction of offset values. To conclude, the QiaXcel system could be considered an effective alternative to existing methods in smaller reference and regional laboratories offering good performance and shorter turnaround times.

MIRU-VNTR Genotyping of Mycobacterium tuberculosis Strains Using QIAxcel Technology: A Multicentre Evaluation Study.

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Vladyslav Nikolayevskyy

Full Text Available Molecular genotyping of M.tuberculosis is an important laboratory tool in the context of emerging drug resistant TB. The standard 24-loci MIRU-VNTR typing includes PCR amplification followed by the detection and sizing of PCR fragments using capillary electrophoresis on automated sequencers or using agarose gels. The QIAxcel Advanced system might offer a cost-effective medium-throughput alternative.Performance characteristics of the QIAxcel Advanced platform for the standard 24 VNTR loci panel was evaluated at two centres on a total of 140 DNA specimens using automated capillary electrophoresis as a reference method. Additionally 4 hypervariable MIRU-VNTR loci were evaluated on 53 crude DNA extracts. The sizing accuracy, interlaboratory reproducibility and overall instrument's performance were assessed during the study.An overall concordance with the reference method was high reaching 98.5% and 97.6% for diluted genomic and crude DNA extracts respectively. 91.4% of all discrepancies were observed in fragments longer than 700bp. The concordance for hypervariable loci was lower except for locus 4120 (96.2%. The interlaboratory reproducibility agreement rates were 98.9% and 91.3% for standard and hypervariable loci, respectively. Overall performance of the QIAxcel platform for M.tuberculosis genotyping using a panel of standard loci is comparable to that of established methods for PCR fragments up to 700bp. Inaccuracies in sizing of longer fragments could be resolved through using in-house size markers or introduction of offset values. To conclude, the QiaXcel system could be considered an effective alternative to existing methods in smaller reference and regional laboratories offering good performance and shorter turnaround times.

Genetic Diversity of the Mycobacterium tuberculosis Beijing Family Based on SNP and VNTR Typing Profiles in Asian Countries

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Chen, Yih-Yuan; Chang, Jia-Ru; Huang, Wei-Feng; Kuo, Shu-Chen; Su, Ih-Jen; Sun, Jun-Ren; Chiueh, Tzong-Shi; Huang, Tsi-Shu; Chen, Yao-Shen; Dou, Horng-Yunn

2012-01-01

The Mycobacterium tuberculosis (MTB) Beijing strain is highly virulent, drug resistant, and endemic over Asia. To explore the genetic diversity of this family in several different regions of eastern Asia, 338 Beijing strains collected in Taiwan (Republic of China) were analyzed by mycobacterial interspersed repetitive unit-variable number tandem repeat (MIRU-VNTR) typing and compared with published MIRU-VNTR profiles and by the Hunter-Gaston diversity index (HGDI) of Beijing strains from Japan and South Korea. The results revealed that VNTR2163b (HGDI>0.6) and five other loci (VNTR424, VNTR4052, VNTR1955, VNTR4156 and VNTR 2996; HGDI>0.3) could be used to discriminate the Beijing strains in a given geographic region. Analysis based on the number of VNTR repeats showed three VNTRs (VNTR424, 3192, and 1955) to be phylogenetically informative loci. In addition, to determine the geographic variation of sequence types in MTB populations, we also compared sequence type (ST) data of our strains with published ST profiles of Beijing strains from Japan and Thailand. ST10, ST22, and ST19 were found to be prevalent in Taiwan (82%) and Thailand (92%). Furthermore, classification of Beijing sublineages as ancient or modern in Taiwan was found to depend on the repeat number of VNTR424. Finally, phylogenetic relationships of MTB isolates in Taiwan, South Korea, and Japan were revealed by a minimum spanning tree based on MIRU-VNTR genotyping. In this topology, the MIRU-VNTR genotypes of the respective clusters were tightly correlated to other genotypic characters. These results are consistent with the hypothesis that clonal evolution of these MTB lineages has occurred. PMID:22808061

Genetic diversity of the Mycobacterium tuberculosis Beijing family based on SNP and VNTR typing profiles in Asian countries.

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Yih-Yuan Chen

Full Text Available The Mycobacterium tuberculosis (MTB Beijing strain is highly virulent, drug resistant, and endemic over Asia. To explore the genetic diversity of this family in several different regions of eastern Asia, 338 Beijing strains collected in Taiwan (Republic of China were analyzed by mycobacterial interspersed repetitive unit-variable number tandem repeat (MIRU-VNTR typing and compared with published MIRU-VNTR profiles and by the Hunter-Gaston diversity index (HGDI of Beijing strains from Japan and South Korea. The results revealed that VNTR2163b (HGDI>0.6 and five other loci (VNTR424, VNTR4052, VNTR1955, VNTR4156 and VNTR 2996; HGDI>0.3 could be used to discriminate the Beijing strains in a given geographic region. Analysis based on the number of VNTR repeats showed three VNTRs (VNTR424, 3192, and 1955 to be phylogenetically informative loci. In addition, to determine the geographic variation of sequence types in MTB populations, we also compared sequence type (ST data of our strains with published ST profiles of Beijing strains from Japan and Thailand. ST10, ST22, and ST19 were found to be prevalent in Taiwan (82% and Thailand (92%. Furthermore, classification of Beijing sublineages as ancient or modern in Taiwan was found to depend on the repeat number of VNTR424. Finally, phylogenetic relationships of MTB isolates in Taiwan, South Korea, and Japan were revealed by a minimum spanning tree based on MIRU-VNTR genotyping. In this topology, the MIRU-VNTR genotypes of the respective clusters were tightly correlated to other genotypic characters. These results are consistent with the hypothesis that clonal evolution of these MTB lineages has occurred.

Molecular characterization of Mycobacterium orygis isolates from wild animals of Nepal.

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Thapa, Jeewan; Nakajima, Chie; Maharjan, Bhagwan; Poudell, Ajay; Suzuki, Yasuhiko

2015-08-01

Mycobacterium orygis, a new member of the Mycobacterium tuberculosis complex, was isolated from a captive spotted deer (Axis axis) and a blue bull (Boselaphus tragocamelus) in Nepal. Analyses by spoligotyping, mycobacterial interspersed repetitive units-variable number of tandem repeats (MIRU-VNTR) typing, region of difference and single nucleotide polymorphism of genes gyrB, mmpL6, TbD1, PPE55 and Rv2042c confirmed the isolates as M. orygis. Moreover, analyses by spoligotyping (SIT587) as well as MIRU-VNTR showed that the isolates shared a similar pattern with many reported isolates. From previous and the present studies, it can be inferred that South Asia is one of the endemic regions for M. orygis. Further investigation including a larger sample size and different host interaction will help to understand the ecology and epidemiology of M. orygis in Nepal.

A first insight on the population structure of Mycobacterium tuberculosis complex as studied by spoligotyping and MIRU-VNTRs in Santiago, Chile.

Science.gov (United States)

Balcells, María Elvira; García, Patricia; Meza, Paulina; Peña, Carlos; Cifuentes, Marcela; Couvin, David; Rastogi, Nalin

2015-01-01

Tuberculosis (TB) remains a significant public health problem worldwide, but the ecology of the prevalent mycobacterial strains, and their transmission, can vary depending on country and region. Chile is a country with low incidence of TB, that has a geographically isolated location in relation to the rest of South American countries due to the Andes Mountains, but recent migration from neighboring countries has changed this situation. We aimed to assess the genotypic diversity of Mycobacterium tuberculosis complex (MTBC) strains in Santiago, Chile, and compare with reports from other Latin-American countries. We analyzed MTBC isolates from pulmonary tuberculosis cases collected between years 2008 and 2013 in Central Santiago, using two genotyping methods: spoligotyping and 12-loci mycobacterial interspersed repetitive unit-variable number of tandem repeats (MIRU-VNTRs). Data obtained were analyzed and compared to the SITVIT2 database. Mean age of the patients was 47.5 years and 61% were male; 11.6% were migrants. Of 103 strains (1 isolate/patient) included, there were 56 distinct spoligotype patterns. Of these, 16 strains (15.5%) corresponded to orphan strains in the SITVIT2 database, not previously reported. Latin American and Mediterranean (LAM) (34%) and T (33%) lineages were the most prevalent strains, followed by Haarlem lineage (16.5%). Beijing family was scarcely represented with only two cases (1.9%), one of them isolated from a Peruvian migrant. The most frequent clustered spoligotypes were SIT33/LAM3 (10.7%), SIT53/T1 (8.7%), SIT50/H3 (7.8%), and SIT37/T3 (6.8%). We conclude that LAM and T genotypes are the most prevalent genotypes of MTBC in Santiago, Chile, and together correspond to almost two thirds of analyzed strains, which is similar to strain distribution reported from other countries of Latin America. Nevertheless, the high proportion of SIT37/T3, which was rarely found in other Latin American countries, may underline a specific history or

Mycobacterial Interspersed Repetitive-Unit–Variable-Number Tandem-Repeat (MIRU-VNTR) Genotyping of Mycobacterium intracellulare for Strain Comparison with Establishment of a PCR-Based Database

Science.gov (United States)

Iakhiaeva, Elena; McNulty, Steven; Brown Elliott, Barbara A.; Falkinham, Joseph O.; Williams, Myra D.; Vasireddy, Ravikiran; Wilson, Rebecca W.; Turenne, Christine

2013-01-01

Strain comparison is important to population genetics and to evaluate relapses in patients with Mycobacterium avium complex (MAC) lung disease, but the “gold standard” of pulsed-field gel electrophoresis (PFGE) is time-consuming and complex. We used variable-number tandem repeats (VNTR) for fingerprinting of respiratory isolates of M. intracellulare from patients with underlying bronchiectasis, to establish a nonsequence-based database for population analysis. Different genotypes identified by PFGE underwent species identification using a 16S rRNA gene multiplex PCR. Genotypes of M. intracellulare were confirmed by internal transcribed spacer 1 (ITS1) sequencing and characterized using seven VNTR primers. The pattern of VNTR amplicon sizes and repeat number defined each specific VNTR type. Forty-two VNTR types were identified among 84 genotypes. PFGE revealed most isolates with the same VNTR type to be clonal or exhibit similar grouping of bands. Repetitive sequence-based PCR (rep-PCR) showed minimal pattern diversity between VNTR types compared to PFGE. Fingerprinting of relapse isolates from 31 treated patients using VNTR combined with 16S multiplex PCR unambiguously and reliably distinguished different genotypes from the same patient, with results comparable to those of PFGE. VNTR for strain comparison is easier and faster than PFGE, is as accurate as PFGE, and does not require sequencing. Starting with a collection of 167 M. intracellulare isolates, VNTR distinguished M. intracellulare into 42 clonal groups. Comparison of isolates from different geographic areas, habitats, and clinical settings is now possible. PMID:23175249

High genetic diversity among Mycobacterium tuberculosis strains in Tehran, Iran

Directory of Open Access Journals (Sweden)

Taher Azimi

2018-05-01

Full Text Available Introduction: Tuberculosis (TB still remains an important public health problem in Iran. The genotyping of Mycobacterium tuberculosis isolates is expected to lead to a better understanding of M. tuberculosis transmission in Tehran, the most populated city of Iran. Materials and Methods: A total of 2300 clinical specimens were obtained from TB suspected patients who were referred to a TB center in Tehran from Jan 2014 to Dec 2016. Identification was performed using both conventional and molecular methods. The presence of resistance to rifampicin was examined by the GeneXpert MTB/RIF. The standard 15-locus mycobacterial interspersed repetitive units-variable number of tandem repeats (MIRU-VNTR typing method was applied to genotype of clinical isolates. Results: Of 2300 specimens, 80 isolates were identified as M. tuberculosis by using biochemical and molecular tests. Of 80 M. tuberculosis isolates, 76 (95% had unique genotypic profiles and 4 (5% shared a profile with one or more other strains. Based on single loci variation (SLV 4 clonal complexes were observed. NEW-1 was found to be the most predominant lineage (22.5% followed by West African (1.25%, Central Asian (CAS/Delhi (1.25%, Bovis (1.25%, H37Rv (1.25% and multiple matches (1.25%. Loci MIRU10, MIRU26, MTUB21 and QUB26 were found as highly discriminative. No mutation was detected in the hotspot region of rifampicin by using GeneXpert MTB/RIF. Conclusions: Our study findings show that there was considerable genotypic diversity among M. tuberculosis isolates in Tehran. The 15-locus MIRU-VNTR showed high HGDI and could be used as a first-line genotyping method for epidemiological studies. Keywords: Mycobacterium tuberculosis, Genotyping, MIRU-VNTR, Tehran, Iran

Increased variability of tornado occurrence in the United States.

Science.gov (United States)

Brooks, Harold E; Carbin, Gregory W; Marsh, Patrick T

2014-10-17

Whether or not climate change has had an impact on the occurrence of tornadoes in the United States has become a question of high public and scientific interest, but changes in how tornadoes are reported have made it difficult to answer it convincingly. We show that, excluding the weakest tornadoes, the mean annual number of tornadoes has remained relatively constant, but their variability of occurrence has increased since the 1970s. This is due to a decrease in the number of days per year with tornadoes combined with an increase in days with many tornadoes, leading to greater variability on annual and monthly time scales and changes in the timing of the start of the tornado season. Copyright © 2014, American Association for the Advancement of Science.

MLVA Based Classification of Mycobacterium tuberculosis Complex Lineages for a Robust Phylogeographic Snapshot of Its Worldwide Molecular Diversity

Science.gov (United States)

Hill, Véronique; Zozio, Thierry; Sadikalay, Syndia; Viegas, Sofia; Streit, Elisabeth; Kallenius, Gunilla; Rastogi, Nalin

2012-01-01

Multiple-locus variable-number tandem repeat analysis (MLVA) is useful to establish transmission routes and sources of infections for various microorganisms including Mycobacterium tuberculosis complex (MTC). The recently released SITVITWEB database contains 12-loci Mycobacterial Interspersed Repetitive Units – Variable Number of Tandem DNA Repeats (MIRU-VNTR) profiles and spoligotype patterns for thousands of MTC strains; it uses MIRU International Types (MIT) and Spoligotype International Types (SIT) to designate clustered patterns worldwide. Considering existing doubts on the ability of spoligotyping alone to reveal exact phylogenetic relationships between MTC strains, we developed a MLVA based classification for MTC genotypic lineages. We studied 6 different subsets of MTC isolates encompassing 7793 strains worldwide. Minimum spanning trees (MST) were constructed to identify major lineages, and the most common representative located as a central node was taken as the prototype defining different phylogenetic groups. A total of 7 major lineages with their respective prototypes were identified: Indo-Oceanic/MIT57, East Asian and African Indian/MIT17, Euro American/MIT116, West African-I/MIT934, West African-II/MIT664, M. bovis/MIT49, M.canettii/MIT60. Further MST subdivision identified an additional 34 sublineage MIT prototypes. The phylogenetic relationships among the 37 newly defined MIRU-VNTR lineages were inferred using a classification algorithm based on a bayesian approach. This information was used to construct an updated phylogenetic and phylogeographic snapshot of worldwide MTC diversity studied both at the regional, sub-regional, and country level according to the United Nations specifications. We also looked for IS6110 insertional events that are known to modify the results of the spoligotyping in specific circumstances, and showed that a fair portion of convergence leading to the currently observed bias in phylogenetic classification of strains may

Investigating a tuberculosis cluster among Filipino health care workers in a low-incidence country.

Science.gov (United States)

Davidson, J A; Fulton, N; Thomas, H L; Lalor, M K; Zenner, D; Brown, T; Murphy, S; Anderson, L F

2018-03-01

Nearly 8% of adult tuberculosis (TB) cases in England, Wales and Northern Ireland (EW&NI) occur among health care workers (HCWs), the majority of whom are from high TB incidence countries. To determine if a TB cluster containing multiple HCWs was due to nosocomial transmission. A cluster of TB cases notified in EW&NI from 2009 to 2014, with indistinguishable 24-locus mycobacterial interspersed repetitive unit-variable number of tandem repeats (MIRU-VNTR) profiles, was identified through routine national cluster review. Cases were investigated to identify epidemiological links, and occupational health (OH) information was collected for HCW cases. To further discriminate strains, typing of eight additional loci was conducted. Of the 53 cases identified, 22 were HCWs. The majority (n = 43), including 21 HCWs, were born in the Philippines. Additional typing split the cluster into three subclusters and seven unique strains. No epidemiological links were identified beyond one household and a common residential area. HCWs in this cluster received no or inadequate OH assessment. The MIRU-VNTR profile of this cluster probably reflects common endemic strains circulating in the Philippines, with reactivation occurring in the UK. Furthermore, 32-locus typing showed that 24-locus MIRU-VNTR failed to distinguish strain diversity. The lack of OH assessment indicates that latent tuberculous infection could have been identified and treated, thereby preventing active cases from occurring.

Genetic diversity of the Mycobacterium tuberculosis East African–Indian family in three tropical Asian countries

Directory of Open Access Journals (Sweden)

Yih-Yuan Chen

2017-12-01

Full Text Available Background: The Beijing lineage of Mycobacterium tuberculosis (MTB is the most predominant MTB strain in Asian countries and is spreading worldwide, however, the East African–Indian (EAI lineage is also particularly prevalent in many tropical Asian countries. The evolutionary relationships among MTB EAI isolates from Taiwan and those of tropical Asian countries remain unknown. Methods: The EAI strains collected from patients in Taiwan were analyzed using spacer oligonucleotide typing and mycobacterial interspersed repetitive unit–variable number of tandem repeats (MIRU-VNTR typing, and compared with published profiles from Cambodia and Singapore to investigate potential epidemiological linkages. Results: Among the three countries, the EAI lineage was most prevalent in Cambodia (60%; Singapore, 25.62%; and Taiwan, 21.85%, having also the highest rates of multidrug resistance and lowest rates of clustering of MTB isolates. We describe a convenient method using seven selected MIRU-VNTR loci for first-line typing to discriminate Beijing and EAI lineages. A potential epidemiological linkage in these tropical Asian countries is also discussed based on a minimum-spanning tree constructed using 24 MIRU-VNTR loci of MTB EAI strains. Conclusion: This study identified evolutionary relationships among MTB EAI isolates from Taiwan and those of two other tropical Asian countries, Cambodia and Singapore. Keywords: East African–Indian family, Mycobacterium tuberculosis, tropical Asian countries

Characterization of Dutch Staphylococcus aureus from bovine mastitis using a Multiple Locus Variable Number Tandem Repeat Analysis

NARCIS (Netherlands)

Ikawaty, R.; Brouwer, E.C.; Jansen, M.D.; Duijkeren, van E.; Mevius, D.J.; Verhoef, J.; Fluit, A.C.

2009-01-01

Current typing methods for Staphylococcus aureus have important drawbacks. We evaluated a Multiple Locus Variable Number Tandem Repeat Analysis (MLVA) scheme with 6 loci which lacks most drawbacks on 85 bovine mastitis isolates from The Netherlands. For each locus the number of repeat units (RU) was

Seasonal unit roots in trade variables

OpenAIRE

Carol Alexander; Manuel Cantavella Jordá

1997-01-01

In this paper we examine the presence of seasonal unit roots in trade variables for Germany, France, the United Kingdom, and Italy, using the procedure developed by Hylleberg, Engle, Granger, and Yoo (1990) [HEGY]. Both quarterly and monthly data reject the presence of unit roots at most seasonal frequencies, more frequently in quarterly than in monthly data. This has important implications for econometric modeling of trade balance, exchange rates and income in European Union (EU) countries. ...

Molecular epidemiology and evolutionary genetics of Mycobacterium tuberculosis in Taipei.

Science.gov (United States)

Dou, Horng-Yunn; Tseng, Fan-Chen; Lin, Chih-Wei; Chang, Jia-Ru; Sun, Jun-Ren; Tsai, Wen-Shing; Lee, Shi-Yi; Su, Ih-Jen; Lu, Jang-Jih

2008-12-22

The control of tuberculosis in densely populated cities is complicated by close human-to-human contacts and potential transmission of pathogens from multiple sources. We conducted a molecular epidemiologic analysis of 356 Mycobacterium tuberculosis (MTB) isolates from patients presenting pulmonary tuberculosis in metropolitan Taipei. Classical antibiogram studies and genetic characterization, using mycobacterial interspersed repetitive-unit-variable-number tandem-repeat (MIRU-VNTR) typing and spoligotyping, were applied after culture. A total of 356 isolates were genotyped by standard spoligotyping and the strains were compared with in the international spoligotyping database (SpolDB4). All isolates were also categorized using the 15 loci MIRU-VNTR typing method and combin with NTF locus and RD deletion analyses. Of 356 isolates spoligotyped, 290 (81.4%) displayed known spoligotypes and 66 were not identified in the database. Major spoligotypes found were Beijing lineages (52.5%), followed by Haarlem lineages (13.5%) and EAI plus EAI-like lineages (11%). When MIRU-VNTR was employed, 140 patterns were identified, including 36 clusters by 252 isolates and 104 unique patterns, and the largest cluster comprised 95 isolates from the Beijing family. The combination of spoligotyping and MIRU-VNTR revealed that 236 (67%) of the 356 isolates were clustered in 43 genotypes. Strains of the Beijing family was more likely to be of modern strain and a higher percentage of multiple drug resistance than other families combined (P = 0.08). Patients infected with Beijing strains were younger than those with other strains (mean 58.7 vs. 64.2, p = 0.02). Moreover, 85.3% of infected persons younger than 25 years had Beijing modern strain, suggesting a possible recent spread in the young population by this family of TB strain in Taipei. Our data on MTB genotype in Taipei suggest that MTB infection has not been optimally controlled. Control efforts should be reinforced in view of the

Genomic diversity of Mycobacterium tuberculosis Beijing strains isolated in Tuscany, Italy, based on large sequence deletions, SNPs in putative DNA repair genes and MIRU-VNTR polymorphisms.

Science.gov (United States)

Garzelli, Carlo; Lari, Nicoletta; Rindi, Laura

2016-03-01

The Beijing genotype of Mycobacterium tuberculosis is cause of global concern as it is rapidly spreading worldwide, is considered hypervirulent, and is most often associated to massive spread of MDR/XDR TB, although these epidemiological or pathological properties have not been confirmed for all strains and in all geographic settings. In this paper, to gain new insights into the biogeographical heterogeneity of the Beijing family, we investigated a global sample of Beijing strains (22% from Italian-born, 78% from foreign-born patients) by determining large sequence polymorphism of regions RD105, RD181, RD150 and RD142, single nucleotide polymorphism of putative DNA repair genes mutT4 and mutT2 and MIRU-VNTR profiles based on 11 discriminative loci. We found that, although our sample of Beijing strains showed a considerable genomic heterogeneity, yielding both ancient and recent phylogenetic strains, the prevalent successful Beijing subsets were characterized by deletions of RD105 and RD181 and by one nucleotide substitution in one or both mutT genes. MIRU-VNTR analysis revealed 47 unique patterns and 9 clusters including a total of 33 isolates (41% of total isolates); the relatively high proportion of Italian-born Beijing TB patients, often occurring in mixed clusters, supports the possibility of an ongoing cross-transmission of the Beijing genotype to autochthonous population. High rates of extra-pulmonary localization and drug-resistance, particularly MDR, frequently reported for Beijing strains in other settings, were not observed in our survey. Copyright © 2015 Elsevier Ltd. All rights reserved.

Use of multiple-locus variable-number tandem-repeats analysis (MLVA) typing to characterize Salmonella Typhimurium DT41 broiler breeder infections

DEFF Research Database (Denmark)

Litrup, E.; Christensen, H.; Nordentoft, Steen

2010-01-01

To characterize isolates of Salmonella Typhimurium DT41 obtained from infected flocks of broiler breeders by multiple-locus variable-number tandem-repeats analysis (MLVA) and compare results with a diverse strain collection from Germany and United Kingdom and isolates from Danish patients. A total...

The number of subjects per variable required in linear regression analyses

NARCIS (Netherlands)

P.C. Austin (Peter); E.W. Steyerberg (Ewout)

2015-01-01

textabstractObjectives To determine the number of independent variables that can be included in a linear regression model. Study Design and Setting We used a series of Monte Carlo simulations to examine the impact of the number of subjects per variable (SPV) on the accuracy of estimated regression

Variable-number-of-tandem-repeats analysis of genetic diversity in Pasteuria ramosa.

Science.gov (United States)

Mouton, L; Ebert, D

2008-05-01

Variable-number-of-tandem-repeats (VNTR) markers are increasingly being used in population genetic studies of bacteria. They were recently developed for Pasteuria ramosa, an endobacterium that infects Daphnia species. In the present study, we genotyped P. ramosa in 18 infected hosts from the United Kingdom, Belgium, and two lakes in the United States using seven VNTR markers. Two Daphnia species were collected: D. magna and D. dentifera. Six loci showed length polymorphism, with as many as five alleles identified for a single locus. Similarity coefficient calculations showed that the extent of genetic variation between pairs of isolates within populations differed according to the population, but it was always less than the genetic distances among populations. Analysis of the genetic distances performed using principal component analysis revealed strong clustering by location of origin, but not by host Daphnia species. Our study demonstrated that the VNTR markers available for P. ramosa are informative in revealing genetic differences within and among populations and may therefore become an important tool for providing detailed analysis of population genetics and epidemiology.

Modeling Turbulent Combustion for Variable Prandtl and Schmidt Number

Science.gov (United States)

Hassan, H. A.

2004-01-01

This report consists of two abstracts submitted for possible presentation at the AIAA Aerospace Science Meeting to be held in January 2005. Since the submittal of these abstracts we are continuing refinement of the model coefficients derived for the case of a variable Turbulent Prandtl number. The test cases being investigated are a Mach 9.2 flow over a degree ramp and a Mach 8.2 3-D calculation of crossing shocks. We have developed an axisymmetric code for treating axisymmetric flows. In addition the variable Schmidt number formulation was incorporated in the code and we are in the process of determining the model constants.

Molecular typing of mycobacterium tuberculosis isolates circulating in Jiangsu Province, China

Directory of Open Access Journals (Sweden)

Dong Haiyan

2011-10-01

Full Text Available Abstract Background Globally, China is the second place with high burden of tuberculosis (TB. To explore the characteristics of the pathogens of Mycobacterium tuberculosis (MTB circulating in this area is helpful for understanding and controlling the spread of the strains. Recent developments in molecular biology have allowed prompt identification and tracking specific strains of MTB spreading through the population. Methods Spacer-oligonucleotide typing (spoligotyping and mycobacterial interspersed repetitive units variable number tandem repeat (MIRU-VNTR were performed in combination to yield specific genetic profiles of 260 MTB strains isolated from 30 counties of Jiangsu province in China between June and July 2010. The spoligotyping results were in comparison to the world Spoligotyping Database of Institute Pasteur de Guadeloupe (SpolDB4. Drug susceptibility test (DST was performed on all strains by proportion method on Lowenstein-Jensen (LJ culture media. Results Based on the spoligotyping method, 246 strains displayed known patterns and 14 were absent in the database. Predominant spoligotypes belonged to the Beijing family (80.4%. By using the 24-loci VNTR typing scheme, 224 different patterns were identified, including 20 clusters and 204 unique patterns. The largest clade comprised 195 strains belonging to the Beijing family. The combination of spoligotyping and 24-loci MIRU-VNTR demonstrated maximal discriminatory power. Furthermore, we observed a significant association between Beijing family strains and drug-resistant phenotypes. The Beijing family strains presented increased risks for developing multi-drug resistant TB, with the OR (95% CI of 11.07(1.45-84.50. Conclusions The present study demonstrated that Beijing family isolates were the most prevalent strains circulating in Jiangsu province of China. The utility of spoligotyping in combination with 24-loci MIRU-VNTR might be a useful tool for epidemiological analysis of MTB

Molecular discrimination of Mycobacterium bovis in São Paulo, Brazil.

Science.gov (United States)

Rocha, Vivianne Cambuí Figueiredo; de Figueiredo, Salomão Cambuí; Rosales, Cesar Alejandro Rodriguez; de Hildebrand e Grisi Filho, José Henrique; Keid, Lara Borges; Soares, Rodrigo Martins; Ferreira Neto, José Soares

2013-01-01

Mycobacterium bovis, a member of the Mycobacterium tuberculosis complex, is the most common agent of cattle tuberculosis, a zoonosis that causes losses in meat and milk production in several countries. In order to support epidemiological studies aimed at controlling the disease, several methods for molecular discrimination of M. bovis isolates have recently been developed. The most frequently used are spacer oligonucleotide typing (spoligotyping), mycobacterial interspersed repetitive units (MIRU), and exact tandem repeat (ETR), but they all have different discriminatory power. In the present study, allelic diversity was calculated for each MIRU and ETR locus, and the Hunter-Gaston discriminatory index (HGI) was calculated for spoligotyping, 10 MIRUs, and 3 ETRs, in 116 isolates of M. bovis obtained from cattle. The analysis of allelic diversity indicated that MIRUs 16, 26, and 27, and ETRs A, B, and C, showed the greatest diversity between the assayed loci. The HGIs for each of the techniques were: spoligotyping=0.738381; MIRU=0.829835; and ETR=0.825337. The associations of the methods' improved discriminatory power were: spoligotyping+MIRU=0.930585; spoligotyping+ETR=0.931034; and MIRU+ETR=0.953373. The greatest discriminatory power was obtained when the three techniques were associated (HGI=0.98051). Considering the analyses of the present study, spoligotyping should be the first method to be used because it differentiates M. bovis from the other members of the Mycobacterium tuberculosis complex. As the associations of MIRU and ETR with spoligotyping resulted in nearly identical HGIs, ETR seems to be the best choice after spoligotyping, because it is faster and more economical than MIRU. Finally, MIRU should be the last method used. In spite of this finding, the choice of the method used should be based on the discriminatory power necessary for the objective at hand.

Minimum number of transfer units and reboiler duty for multicomponent distillation columns

International Nuclear Information System (INIS)

Pleşu, Valentin; Bonet Ruiz, Alexandra Elena; Bonet, Jordi; Llorens, Joan; Iancu, Petrica

2013-01-01

Some guidelines to evaluate distillation columns, considering only basic thermodynamic data and principles, are provided in this paper. The method allows a first insight to the problem by simple calculations, without requiring column variables to ensure rational use of energy and low environmental impact. The separation system is approached by two complementary ways: minimum and infinite reflux flow rate. The minimum reflux provides the minimum energy requirements, and the infinite reflux provides the feasibility conditions. The difficulty of separation can be expressed in terms of number of transfer units (NTU). The applicability of the method is not mathematically limited by the number of components in the mixture. It is also applicable to reactive distillation. Several mixtures, including reactive distillation, are rigorously simulated as illustrative examples, to verify the applicability of the approach. The separation of the mixtures, performed by distillation columns, is feasible if a minimum NTU can be calculated between the distillate and bottom products. Once verified the feasibility of the separation, the maximum thermal efficiency depends only on boiling point of bottom and distillate streams. The minimum energy requirements corresponding to the reboiler can be calculated from the maximum thermal efficiency, and the variation of entropy and enthalpy of mixing between distillate and bottom streams. -- Highlights: • Feasibility analysis complemented with difficulty of separation parameters • Minimum and infinite reflux simplified models for distillation columns • Minimum number of transfer units (NTU) for packed columns at early design stages • Calculation of minimum energy distillation requirements at early design stages • Thermodynamic cycle approach and efficiency for distillation columns

A Finer Classification of the Unit Sum Number of the Ring of Integers ...

Indian Academy of Sciences (India)

Here we introduce a finer classification for the unit sum number of a ring and in this new classification we completely determine the unit sum number of the ring of integers of a quadratic field. Further we obtain some results on cubic complex fields which one can decide whether the unit sum number is or ∞. Then we ...

Modeling and designing of variable-period and variable-pole-number undulator

Directory of Open Access Journals (Sweden)

I. Davidyuk

2016-02-01

Full Text Available The concept of permanent-magnet variable-period undulator (VPU was proposed several years ago and has found few implementations so far. The VPUs have some advantages as compared with conventional undulators, e.g., a wider range of radiation wavelength tuning and the option to increase the number of poles for shorter periods. Both these advantages will be realized in the VPU under development now at Budker INP. In this paper, we present the results of 2D and 3D magnetic field simulations and discuss some design features of this VPU.

Variability and trends in dry day frequency and dry event length in the southwestern United States

Science.gov (United States)

McCabe, Gregory J.; Legates, David R.; Lins, Harry F.

2010-01-01

Daily precipitation from 22 National Weather Service first-order weather stations in the southwestern United States for water years 1951 through 2006 are used to examine variability and trends in the frequency of dry days and dry event length. Dry events with minimum thresholds of 10 and 20 consecutive days of precipitation with less than 2.54 mm are analyzed. For water years and cool seasons (October through March), most sites indicate negative trends in dry event length (i.e., dry event durations are becoming shorter). For the warm season (April through September), most sites also indicate negative trends; however, more sites indicate positive trends in dry event length for the warm season than for water years or cool seasons. The larger number of sites indicating positive trends in dry event length during the warm season is due to a series of dry warm seasons near the end of the 20th century and the beginning of the 21st century. Overall, a large portion of the variability in dry event length is attributable to variability of the El Niño–Southern Oscillation, especially for water years and cool seasons. Our results are consistent with analyses of trends in discharge for sites in the southwestern United States, an increased frequency in El Niño events, and positive trends in precipitation in the southwestern United States.

Observer variability in estimating numbers: An experiment

Science.gov (United States)

Erwin, R.M.

1982-01-01

Census estimates of bird populations provide an essential framework for a host of research and management questions. However, with some exceptions, the reliability of numerical estimates and the factors influencing them have received insufficient attention. Independent of the problems associated with habitat type, weather conditions, cryptic coloration, ete., estimates may vary widely due only to intrinsic differences in observers? abilities to estimate numbers. Lessons learned in the field of perceptual psychology may be usefully applied to 'real world' problems in field ornithology. Based largely on dot discrimination tests in the laboratory, it was found that numerical abundance, density of objects, spatial configuration, color, background, and other variables influence individual accuracy in estimating numbers. The primary purpose of the present experiment was to assess the effects of observer, prior experience, and numerical range on accuracy in estimating numbers of waterfowl from black-and-white photographs. By using photographs of animals rather than black dots, I felt the results could be applied more meaningfully to field situations. Further, reinforcement was provided throughout some experiments to examine the influence of training on accuracy.

Role of updraft velocity in temporal variability of global cloud hydrometeor number

Science.gov (United States)

Sullivan, Sylvia C.; Lee, Dongmin; Oreopoulos, Lazaros; Nenes, Athanasios

2016-05-01

Understanding how dynamical and aerosol inputs affect the temporal variability of hydrometeor formation in climate models will help to explain sources of model diversity in cloud forcing, to provide robust comparisons with data, and, ultimately, to reduce the uncertainty in estimates of the aerosol indirect effect. This variability attribution can be done at various spatial and temporal resolutions with metrics derived from online adjoint sensitivities of droplet and crystal number to relevant inputs. Such metrics are defined and calculated from simulations using the NASA Goddard Earth Observing System Model, Version 5 (GEOS-5) and the National Center for Atmospheric Research Community Atmosphere Model Version 5.1 (CAM5.1). Input updraft velocity fluctuations can explain as much as 48% of temporal variability in output ice crystal number and 61% in droplet number in GEOS-5 and up to 89% of temporal variability in output ice crystal number in CAM5.1. In both models, this vertical velocity attribution depends strongly on altitude. Despite its importance for hydrometeor formation, simulated vertical velocity distributions are rarely evaluated against observations due to the sparsity of relevant data. Coordinated effort by the atmospheric community to develop more consistent, observationally based updraft treatments will help to close this knowledge gap.

21 CFR 203.38 - Sample lot or control numbers; labeling of sample units.

Science.gov (United States)

2010-04-01

... numbers; labeling of sample units. (a) Lot or control number required on drug sample labeling and sample... identifying lot or control number that will permit the tracking of the distribution of each drug sample unit... 21 Food and Drugs 4 2010-04-01 2010-04-01 false Sample lot or control numbers; labeling of sample...

Raw and Central Moments of Binomial Random Variables via Stirling Numbers

Science.gov (United States)

Griffiths, Martin

2013-01-01

We consider here the problem of calculating the moments of binomial random variables. It is shown how formulae for both the raw and the central moments of such random variables may be obtained in a recursive manner utilizing Stirling numbers of the first kind. Suggestions are also provided as to how students might be encouraged to explore this…

Corrective action investigation plan for Corrective Action Unit Number 427: Area 3 septic waste system numbers 2 and 6, Tonopah Test Range, Nevada

International Nuclear Information System (INIS)

1997-01-01

This Corrective Action Investigation Plan (CAIP) contains the environmental sample collection objectives and the criteria for conducting site investigation activities at the Area 3 Compound, specifically Corrective Action Unit (CAU) Number 427, which is located at the Tonopah Test Range (TTR). The TTR, included in the Nellis Air Force Range, is approximately 255 kilometers (140 miles) northwest of Las Vegas, Nevada. The Corrective Action Unit Work Plan, Tonopah Test Range, Nevada divides investigative activities at TTR into Source Groups. The Septic Tanks and Lagoons Group consists of seven CAUs. Corrective Action Unit Number 427 is one of three septic waste system CAUs in TTR Area 3. Corrective Action Unit Numbers 405 and 428 will be investigated at a future data. Corrective Action Unit Number 427 is comprised of Septic Waste Systems Number 2 and 6 with respective CAS Numbers 03-05-002-SW02 and 03-05-002-SW06

Rational and irrational numbers from unit resistors

International Nuclear Information System (INIS)

Kasperski, Maciej; Kłobus, Waldemar

2014-01-01

We address the problem of constructing a network of unit resistors such that it enables the retrieval of an arbitrary value of equivalent resistance. In particular, we employ the notion of continued fractions to construct a ladder network by which we can easily obtain any fractional value resistance. In addition, since any irrational number is associated with an infinite continued fraction, we discuss the convergence of the equivalent resistance of an infinite resistive ladder and various aspects concerning the approximations of arbitrary numbers attained by adding additional resistors successively to the network. The presented methods can be easily implemented in an educational laboratory and offer an interesting addition to the topic of Ohm’s law. (paper)

Clinical data and molecular analysis of Mycobacterium tuberculosi isolates from drug-resistant tuberculosis patients in Goiás, Brazil

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Sueli Lemes de Ávila Alves

2011-09-01

Full Text Available Drug resistance is one of the major concerns regarding tuberculosis (TB infection worldwide because it hampers control of the disease. Understanding the underlying mechanisms responsible for drug resistance development is of the highest importance. To investigate clinical data from drug-resistant TB patients at the Tropical Diseases Hospital, Goiás (GO, Brazil and to evaluate the molecular basis of rifampin (R and isoniazid (H resistance in Mycobacterium tuberculosis. Drug susceptibility testing was performed on 124 isolates from 100 patients and 24 isolates displayed resistance to R and/or H. Molecular analysis of drug resistance was performed by partial sequencing of the rpoB and katGgenes and analysis of the inhA promoter region. Similarity analysis of isolates was performed by 15 loci mycobacterial interspersed repetitive unit-variable number tandem repeat (MIRU-VNTR typing. The molecular basis of drug resistance among the 24 isolates from 16 patients was confirmed in 18 isolates. Different susceptibility profiles among the isolates from the same individual were observed in five patients; using MIRU-VNTR, we have shown that those isolates were not genetically identical, with differences in one to three loci within the 15 analysed loci. Drug-resistant TB in GO is caused by M. tuberculosis strains with mutations in previously described sites of known genes and some patients harbour a mixed phenotype infection as a consequence of a single infective event; however, further and broader investigations are needed to support our findings.

Virulence of Mycobacterium avium Subsp. hominissuis Human Isolates in an in vitro Macrophage Infection Model

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Laura Rindi

2018-01-01

Full Text Available Background: Mycobacterium avium subsp. hominissuis (MAH is an environmental opportunistic pathogen for humans and swine worldwide; in humans, the vast majority of MAH infections is due to strains belonging to specific genotypes, such as the internal transcribed spacer (ITS-sequevars Mav-A and Mav-B that mostly cause pulmonary infections in elderly patients and severe disseminated infections in acquired immunodeficiency syndrome patients, respectively. To test whether the different types of infections in distinct patients' populations might reflect a different virulence of the infecting genotypes, MAH human isolates, genotyped by ITS sequencing and MIRU-VNTR minisatellite analysis, were studied for the capacity to infect and replicate in human macrophages in vitro. Methods: Cultures of human peripheral blood mononuclear cells and phagocytic human leukemic cell line THP-1 cells were infected with each MAH isolate and intracellular colony-forming units (CFU were determined. Results: At 2 h after infection, i.e., immediately after cell entry, the numbers of intracellular bacteria did not differ between Mav-A and Mav-B organisms in both phagocytic cell types. At 5 days, Mav-A organisms, sharing highly related VNTR-MIRU genotypes, yielded numbers of intracellular CFUs significantly higher than Mav-B organisms in both phagocytic cell types. MIRU-VNTR-based minimum spanning tree analysis of the MAH isolates showed a divergent phylogenetic pathway of Mav-A and Mav-B organisms. Conclusion: Mav-A and Mav-B sequevars might have evolved different pathogenetic properties that might account for their association with different human infections.

The role of updraft velocity in temporal variability of cloud hydrometeor number

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Sullivan, Sylvia; Nenes, Athanasios; Lee, Dong Min; Oreopoulos, Lazaros

2016-04-01

Significant effort has been dedicated to incorporating direct aerosol-cloud links, through parameterization of liquid droplet activation and ice crystal nucleation, within climate models. This significant accomplishment has generated the need for understanding which parameters affecting hydrometer formation drives its variability in coupled climate simulations, as it provides the basis for optimal parameter estimation as well as robust comparison with data, and other models. Sensitivity analysis alone does not address this issue, given that the importance of each parameter for hydrometer formation depends on its variance and sensitivity. To address the above issue, we develop and use a series of attribution metrics defined with adjoint sensitivities to attribute the temporal variability in droplet and crystal number to important aerosol and dynamical parameters. This attribution analysis is done both for the NASA Global Modeling and Assimilation Office Goddard Earth Observing System Model, Version 5 and the National Center for Atmospheric Research Community Atmosphere Model Version 5.1. Within the GEOS simulation, up to 48% of temporal variability in output ice crystal number and 61% in droplet number can be attributed to input updraft velocity fluctuations, while for the CAM simulation, they explain as much as 89% of the ice crystal number variability. This above results suggest that vertical velocity in both model frameworks is seen to be a very important (or dominant) driver of hydrometer variability. Yet, observations of vertical velocity are seldomly available (or used) to evaluate the vertical velocities in simulations; this strikingly contrasts the amount and quality of data available for aerosol-related parameters. Consequentially, there is a strong need for retrievals or measurements of vertical velocity for addressing this important knowledge gap that requires a significant investment and effort by the atmospheric community. The attribution metrics as a

Prospective Elementary Teachers' Conceptions of Unitizing with Whole Numbers and Fractions

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Tobias, Jennifer M.; Roy, George J.; Safi, Farshid

2015-01-01

This article examines prospective elementary teachers' conceptions of unitizing with whole numbers and fraction concepts and operations throughout a semester-long mathematics content course. Student work samples and classroom conversations are used to illustrate the types of unitizing understandings that prospective teachers bring to teacher…

The number of subjects per variable required in linear regression analyses.

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Austin, Peter C; Steyerberg, Ewout W

2015-06-01

To determine the number of independent variables that can be included in a linear regression model. We used a series of Monte Carlo simulations to examine the impact of the number of subjects per variable (SPV) on the accuracy of estimated regression coefficients and standard errors, on the empirical coverage of estimated confidence intervals, and on the accuracy of the estimated R(2) of the fitted model. A minimum of approximately two SPV tended to result in estimation of regression coefficients with relative bias of less than 10%. Furthermore, with this minimum number of SPV, the standard errors of the regression coefficients were accurately estimated and estimated confidence intervals had approximately the advertised coverage rates. A much higher number of SPV were necessary to minimize bias in estimating the model R(2), although adjusted R(2) estimates behaved well. The bias in estimating the model R(2) statistic was inversely proportional to the magnitude of the proportion of variation explained by the population regression model. Linear regression models require only two SPV for adequate estimation of regression coefficients, standard errors, and confidence intervals. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Testing a model of componential processing of multi-symbol numbers-evidence from measurement units.

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Huber, Stefan; Bahnmueller, Julia; Klein, Elise; Moeller, Korbinian

2015-10-01

Research on numerical cognition has addressed the processing of nonsymbolic quantities and symbolic digits extensively. However, magnitude processing of measurement units is still a neglected topic in numerical cognition research. Hence, we investigated the processing of measurement units to evaluate whether typical effects of multi-digit number processing such as the compatibility effect, the string length congruity effect, and the distance effect are also present for measurement units. In three experiments, participants had to single out the larger one of two physical quantities (e.g., lengths). In Experiment 1, the compatibility of number and measurement unit (compatible: 3 mm_6 cm with 3 mm) as well as string length congruity (congruent: 1 m_2 km with m 2 characters) were manipulated. We observed reliable compatibility effects with prolonged reaction times (RT) for incompatible trials. Moreover, a string length congruity effect was present in RT with longer RT for incongruent trials. Experiments 2 and 3 served as control experiments showing that compatibility effects persist when controlling for holistic distance and that a distance effect for measurement units exists. Our findings indicate that numbers and measurement units are processed in a componential manner and thus highlight that processing characteristics of multi-digit numbers generalize to measurement units. Thereby, our data lend further support to the recently proposed generalized model of componential multi-symbol number processing.

Evidence for increasingly variable Palmer Drought Severity Index in the United States since 1895.

Science.gov (United States)

Rayne, Sierra; Forest, Kaya

2016-02-15

Annual and summertime trends towards increasingly variable values of the Palmer Drought Severity Index (PDSI) over a sub-decadal period (five years) were investigated within the contiguous United States between 1895 and the present. For the contiguous United States as a whole, there is a significant increasing trend in the five-year running minimum-maximum ranges for the annual PDSI (aPDSI5 yr(min|max, range)). During this time frame, the average aPDSI5 yr(min|max, range) has increased by about one full unit, indicating a substantial increase in drought variability over short time scales across the United States. The end members of the running aPDSI5 yr(min|max, range) highlight even more rapid changes in the drought index variability within the past 120 years. This increasing variability in the aPDSI5 yr(min|max, range) is driven primarily by changes taking place in the Pacific and Atlantic Ocean coastal climate regions, climate regions which collectively comprise one-third the area of the contiguous United States. Similar trends were found for the annual and summertime Palmer Hydrological Drought Index (PHDI), the Palmer Modified Drought Index (PMDI), and the Palmer Z Index (PZI). Overall, interannual drought patterns in the contiguous United States are becoming more extreme and difficult to predict, posing a challenge to agricultural and other water-resource related planning efforts. Copyright © 2015 Elsevier B.V. All rights reserved.

Variability of pesticide residues in eggplant units collected from a field trial and marketplaces in Greece.

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Prodhan, Mohammad Dalower Hossain; Papadakis, Emmanouil-Nikolaos; Papadopoulou-Mourkidou, Euphemia

2018-04-01

Variability of pesticide residues among food items is very important when assessing the risks and food safety for the consumers. Therefore, the present study was undertaken to estimate the unit-to-unit residue variability factors for eggplant. In total, 120 samples from a trial field and 142 samples from different marketplaces in Thessaloniki, Greece, were collected to estimate the variability of pesticide residues in eggplant units. They were extracted by the QuEChERS method and the residues were determined by LC-MS/MS. For the field samples, the unit-to-unit variability factors (VFs) obtained for cypermethrin and deltamethrin residues were 2.54 and 2.51, respectively. The mean residue levels of both pesticides were higher in the composite samples than in the individual samples. The average VFs for the marketplace samples was 3.89. The eggplant units exposed to pesticides were higher in residues than the non-exposed units. The variability factors obtained in the marketplace samples were higher than those in the samples collected from the field trial. A default VF value of 3 for field trials is appropriate for use when assessing the acute dietary intake but a VF for the marketplace samples should be reconsidered with a larger data. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Evolutionary history of the PER3 variable number of tandem repeats (VNTR): idiosyncratic aspect of primate molecular circadian clock.

Science.gov (United States)

Sabino, Flávia Cal; Ribeiro, Amanda Oliveira; Tufik, Sérgio; Torres, Laila Brito; Oliveira, José Américo; Mello, Luiz Eugênio Araújo Moraes; Cavalcante, Jeferson Souza; Pedrazzoli, Mario

2014-01-01

The PER3 gene is one of the clock genes, which function in the core mammalian molecular circadian system. A variable number of tandem repeats (VNTR) locus in the 18th exon of this gene has been strongly associated to circadian rhythm phenotypes and sleep organization in humans, but it has not been identified in other mammals except primates. To better understand the evolution and the placement of the PER3 VNTR in a phylogenetical context, the present study enlarges the investigation about the presence and the structure of this variable region in a large sample of primate species and other mammals. The analysis of the results has revealed that the PER3 VNTR occurs exclusively in simiiforme primates and that the number of copies of the primitive unit ranges from 2 to 11 across different primate species. Two transposable elements surrounding the 18th exon of PER3 were found in primates with published genome sequences, including the tarsiiforme Tarsius syrichta, which lacks the VNTR. These results suggest that this VNTR may have evolved in a common ancestor of the simiiforme branch and that the evolutionary copy number differentiation of this VNTR may be associated with primate simiiformes sleep and circadian phenotype patterns.

Evolutionary history of the PER3 variable number of tandem repeats (VNTR: idiosyncratic aspect of primate molecular circadian clock.

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Flávia Cal Sabino

Full Text Available The PER3 gene is one of the clock genes, which function in the core mammalian molecular circadian system. A variable number of tandem repeats (VNTR locus in the 18th exon of this gene has been strongly associated to circadian rhythm phenotypes and sleep organization in humans, but it has not been identified in other mammals except primates. To better understand the evolution and the placement of the PER3 VNTR in a phylogenetical context, the present study enlarges the investigation about the presence and the structure of this variable region in a large sample of primate species and other mammals. The analysis of the results has revealed that the PER3 VNTR occurs exclusively in simiiforme primates and that the number of copies of the primitive unit ranges from 2 to 11 across different primate species. Two transposable elements surrounding the 18th exon of PER3 were found in primates with published genome sequences, including the tarsiiforme Tarsius syrichta, which lacks the VNTR. These results suggest that this VNTR may have evolved in a common ancestor of the simiiforme branch and that the evolutionary copy number differentiation of this VNTR may be associated with primate simiiformes sleep and circadian phenotype patterns.

Clinical Trials With Large Numbers of Variables: Important Advantages of Canonical Analysis.

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Cleophas, Ton J

2016-01-01

Canonical analysis assesses the combined effects of a set of predictor variables on a set of outcome variables, but it is little used in clinical trials despite the omnipresence of multiple variables. The aim of this study was to assess the performance of canonical analysis as compared with traditional multivariate methods using multivariate analysis of covariance (MANCOVA). As an example, a simulated data file with 12 gene expression levels and 4 drug efficacy scores was used. The correlation coefficient between the 12 predictor and 4 outcome variables was 0.87 (P = 0.0001) meaning that 76% of the variability in the outcome variables was explained by the 12 covariates. Repeated testing after the removal of 5 unimportant predictor and 1 outcome variable produced virtually the same overall result. The MANCOVA identified identical unimportant variables, but it was unable to provide overall statistics. (1) Canonical analysis is remarkable, because it can handle many more variables than traditional multivariate methods such as MANCOVA can. (2) At the same time, it accounts for the relative importance of the separate variables, their interactions and differences in units. (3) Canonical analysis provides overall statistics of the effects of sets of variables, whereas traditional multivariate methods only provide the statistics of the separate variables. (4) Unlike other methods for combining the effects of multiple variables such as factor analysis/partial least squares, canonical analysis is scientifically entirely rigorous. (5) Limitations include that it is less flexible than factor analysis/partial least squares, because only 2 sets of variables are used and because multiple solutions instead of one is offered. We do hope that this article will stimulate clinical investigators to start using this remarkable method.

Computational procedure of optimal inventory model involving controllable backorder rate and variable lead time with defective units

Science.gov (United States)

Lee, Wen-Chuan; Wu, Jong-Wuu; Tsou, Hsin-Hui; Lei, Chia-Ling

2012-10-01

This article considers that the number of defective units in an arrival order is a binominal random variable. We derive a modified mixture inventory model with backorders and lost sales, in which the order quantity and lead time are decision variables. In our studies, we also assume that the backorder rate is dependent on the length of lead time through the amount of shortages and let the backorder rate be a control variable. In addition, we assume that the lead time demand follows a mixture of normal distributions, and then relax the assumption about the form of the mixture of distribution functions of the lead time demand and apply the minimax distribution free procedure to solve the problem. Furthermore, we develop an algorithm procedure to obtain the optimal ordering strategy for each case. Finally, three numerical examples are also given to illustrate the results.

[Quantitative analysis of drug expenditures variability in dermatology units].

Science.gov (United States)

Moreno-Ramírez, David; Ferrándiz, Lara; Ramírez-Soto, Gabriel; Muñoyerro, M Dolores

2013-01-01

Variability in adjusted drug expenditures among clinical departments raises the possibility of difficult access to certain therapies at the time that avoidable expenditures may also exist. Nevertheless, drug expenditures are not usually applied to clinical practice variability analysis. To identify and quantify variability in drug expenditures in comparable dermatology department of the Servicio Andaluz de Salud. Comparative economic analysis regarding the drug expenditures adjusted to population and health care production in 18 dermatology departments of the Servicio Andaluz de Salud. The 2012 cost and production data (homogeneous production units -HPU-)were provided by Inforcoan, the cost accounting information system of the Servicio Andaluz de Salud. The observed drug expenditure ratio ranged from 0.97?/inh to 8.90?/inh and from 208.45?/HPU to 1,471.95?/ HPU. The Pearson correlation between drug expenditure and population was 0.25 and 0.35 for the correlation between expenditure and homogeneous production (p=0.32 and p=0,15, respectively), both Pearson coefficients confirming the lack of correlation and arelevant degree of variability in drug expenditures. The quantitative analysis of variability performed through Pearson correlation has confirmed the existence of drug expenditure variability among comparable dermatology departments. Copyright © 2013 SEFH. Published by AULA MEDICA. All rights reserved.

The Curve Number Concept as a Driver for Delineating Hydrological Response Units

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Eleni Savvidou

2018-02-01

Full Text Available In this paper, a new methodology for delineating Hydrological Response Units (HRUs, based on the Curve Number (CN concept, is presented. Initially, a semi-automatic procedure in a GIS environment is used to produce basin maps of distributed CN values as the product of the three classified layers, soil permeability, land use/land cover characteristics and drainage capacity. The map of CN values is used in the context of model parameterization, in order to identify the essential number and spatial extent of HRUs and, consequently, the number of control variables of the calibration problem. The new approach aims at reducing the subjectivity introduced by the definition of HRUs and providing parsimonious modelling schemes. In particular, the CN-based parameterization (1 allows the user to assign as many parameters as can be supported by the available hydrological information, (2 associates the model parameters with anticipated basin responses, as quantified in terms of CN classes across HRUs, and (3 reduces the effort for model calibration, simultaneously ensuring good predictive capacity. The advantages of the proposed approach are demonstrated in the hydrological simulation of the Nedontas River Basin, Greece, where parameterizations of different complexities are employed in a recently improved version of the HYDROGEIOS model. A modelling experiment with a varying number of HRUs, where the parameter estimation problem was handled through automatic optimization, showed that the parameterization with three HRUs, i.e., equal to the number of flow records, ensured the optimal performance. Similarly, tests with alternative HRU configurations confirmed that the optimal scores, both in calibration and validation, were achieved by the CN-based approach, also resulting in parameters values across the HRUs that were in agreement with their physical interpretation.

Speed of the bacterial flagellar motor near zero load depends on the number of stator units.

Science.gov (United States)

Nord, Ashley L; Sowa, Yoshiyuki; Steel, Bradley C; Lo, Chien-Jung; Berry, Richard M

2017-10-31

The bacterial flagellar motor (BFM) rotates hundreds of times per second to propel bacteria driven by an electrochemical ion gradient. The motor consists of a rotor 50 nm in diameter surrounded by up to 11 ion-conducting stator units, which exchange between motors and a membrane-bound pool. Measurements of the torque-speed relationship guide the development of models of the motor mechanism. In contrast to previous reports that speed near zero torque is independent of the number of stator units, we observe multiple speeds that we attribute to different numbers of units near zero torque in both Na + - and H + -driven motors. We measure the full torque-speed relationship of one and two H + units in Escherichia coli by selecting the number of H + units and controlling the number of Na + units in hybrid motors. These experiments confirm that speed near zero torque in H + -driven motors increases with the stator number. We also measured 75 torque-speed curves for Na + -driven chimeric motors at different ion-motive force and stator number. Torque and speed were proportional to ion-motive force and number of stator units at all loads, allowing all 77 measured torque-speed curves to be collapsed onto a single curve by simple rescaling. Published under the PNAS license.

Analysis of the actual number of physicians in radiotherapy units in Germany

International Nuclear Information System (INIS)

Guttenberger, R.; Witucki, G.

2002-01-01

Background: Physician workload directly influences the ability of an institution to provide high standards in radiotherapy services. Materials and Methods: Data of 189 radiotherapy units of the DEGRO survey 2000 complemented and corrected (Table 1) are analyzed with simple and multiple linear regression (models in Table 2). Results: In 21 private radiotherapy facilities actual numbers of physicians split up in 0.19 for every 1,000 megavoltage courses per year, 1.8 per megavoltage unit, 0.68 for every ten beds for inpatients minus 0.67 or plus 1.2 physicians per facility providing radiotherapy only or combined with other services, respectively. Radiotherapy units in hospitals were analyzed in two groups, i.e. radiotherapy only (n=69) or in combination with other services (n=59). In the latter, reported numbers of physicians split up in 3.2 for every 1,000 megavoltage courses per year, minus 0.13 per megavoltage unit, 0.87 for every ten beds for inpatients, plus 2.2 per facility. Units providing radiotherapy only had 0.86 physicians for every 1,000 megavoltage courses per year plus 1.0 per megavoltage unit plus 0.97 for every ten beds plus 1.0 per facility. In 36 radiotherapy university clinics actual numbers of physicians split up in 2.4 for every 1,000 megavoltage courses per year, 1.7 per megavoltage unit, 0.86 for every ten beds for inpatients, plus 1.5 per clinic. For confidence limits see Table 3, for results of univariate analysis Figures 1 and 2. Conclusion: In German radiotherapy facilities, physician workload varies considerably. It exceeds that reported for the USA by a substantial margin. (orig.) [de

Recent trends in the variability of halogenated trace gases over the United States

Science.gov (United States)

Hurst, Dale F.; Bakwin, Peter S.; Elkins, James W.

1998-10-01

Recent trends in the atmospheric variability of seven halogenated trace gases are determined from three years (November 1994 through October 1997) of hourly gas chromatographic measurements at a 610 m tower in North Carolina and 17 months (June 1996 through October 1997) of similar measurements at a 450 m tower in Wisconsin. Production of five of these gases, CCl3F (CFC-11), CCl2F2 (CFC-12), CCl2FCClF2 (CFC-113), CH3CCl3 (methyl chloroform), and CCl4 (carbon tetrachloride), is now strictly regulated in the United States and other developed countries under international legislation. C2Cl4 (tetrachloroethene) and SF6 (sulfur hexafluoride) are currently produced without restriction, but requests for voluntary cutbacks in C2Cl4 emissions have been made, at least in the United States. Atmospheric variability of these gases is examined at several sampling heights on the towers, but trends are deduced using only nighttime data at the top sampling level of each tower to minimize variability driven by local emissions and the diurnal cycle of the planetary boundary layer, leaving regional emissions as the main source of day-to-day variability. Significant downward trends are determined for CFC-12, CFC-113, CH3CCl3, and C2Cl4 variability at both towers, reflecting decreased emissions of these gases in two regions of the United States. Trends in CFC-11, CCl4, and SF6 variability at both towers are not significantly different from zero.

High-Performance Pseudo-Random Number Generation on Graphics Processing Units

OpenAIRE

Nandapalan, Nimalan; Brent, Richard P.; Murray, Lawrence M.; Rendell, Alistair

2011-01-01

This work considers the deployment of pseudo-random number generators (PRNGs) on graphics processing units (GPUs), developing an approach based on the xorgens generator to rapidly produce pseudo-random numbers of high statistical quality. The chosen algorithm has configurable state size and period, making it ideal for tuning to the GPU architecture. We present a comparison of both speed and statistical quality with other common parallel, GPU-based PRNGs, demonstrating favourable performance o...

Dominant incidence of multidrug and extensively drug-resistant specific Mycobacterium tuberculosis clones in Osaka Prefecture, Japan.

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Aki Tamaru

Full Text Available Infection and transmission of multidrug-resistant Mycobacterium tuberculosis (MDR-Mtb and extensively drug-resistant M. tuberculosis (XDR-Mtb is a serious health problem. We analyzed a total of 1,110 Mtb isolates in Osaka Prefecture and neighboring areas from April 2000 to March 2009. A total of 89 MDR-Mtb were identified, 36 (48.5% of which were determined to be XDR-Mtb. Among the 89 MDR-Mtb isolates, 24 (27.0% phylogenetically distributed into six clusters based on mycobacterial interspersed repetitive units-various number of tandem repeats (MIRU-VNTR typing. Among these six clusters, the MIRU-VNTR patterns of four (OM-V02, OM-V03, OM-V04, and OM-V06 were only found for MDR-Mtb. Further analysis revealed that all isolates belonging to OM-V02 and OM-V03, and two isolates from OM-V04 were clonal. Importantly such genotypes were not observed for drug-sensitive isolates. These suggest that few but transmissible clones can transmit after acquiring multidrug resistance and colonize even in a country with a developed, well-organized healthcare system.

Detection of a variable number of ribosomal DNA loci by fluorescent in situ hybridization in Populus species.

Science.gov (United States)

Prado, E A; Faivre-Rampant, P; Schneider, C; Darmency, M A

1996-10-01

Fluorescent in situ hybridization (FISH) was applied to related Populus species (2n = 19) in order to detect rDNA loci. An interspecific variability in the number of hybridization sites was revealed using as probe an homologous 25S clone from Populus deltoides. The application of image analysis methods to measure fluorescence intensity of the hybridization signals has enabled us to characterize major and minor loci in the 18S-5.8S-25S rDNA. We identified one pair of such rDNA clusters in Populus alba; two pairs, one major and one minor, in both Populus nigra and P. deltoides; and three pairs in Populus balsamifera, (two major and one minor) and Populus euroamericana (one major and two minor). FISH results are in agreement with those based on RFLP analysis. The pBG13 probe containing 5S sequence from flax detected two separate clusters corresponding to the two size classes of units that coexist within 5S rDNA of most Populus species. Key words : Populus spp., fluorescent in situ hybridization, FISH, rDNA variability, image analysis.

Understanding Cirrus Ice Crystal Number Variability for Different Heterogeneous Ice Nucleation Spectra

Science.gov (United States)

Sullivan, Sylvia C.; Betancourt, Ricardo Morales; Barahona, Donifan; Nenes, Athanasios

2016-01-01

Along with minimizing parameter uncertainty, understanding the cause of temporal and spatial variability of the nucleated ice crystal number, Ni, is key to improving the representation of cirrus clouds in climate models. To this end, sensitivities of Ni to input variables like aerosol number and diameter provide valuable information about nucleation regime and efficiency for a given model formulation. Here we use the adjoint model of the adjoint of a cirrus formation parameterization (Barahona and Nenes, 2009b) to understand Ni variability for various ice-nucleating particle (INP) spectra. Inputs are generated with the Community Atmosphere Model version 5, and simulations are done with a theoretically derived spectrum, an empirical lab-based spectrum and two field-based empirical spectra that differ in the nucleation threshold for black carbon particles and in the active site density for dust. The magnitude and sign of Ni sensitivity to insoluble aerosol number can be directly linked to nucleation regime and efficiency of various INP. The lab-based spectrum calculates much higher INP efficiencies than field-based ones, which reveals a disparity in aerosol surface properties. Ni sensitivity to temperature tends to be low, due to the compensating effects of temperature on INP spectrum parameters; this low temperature sensitivity regime has been experimentally reported before but never deconstructed as done here.

Equivalence of the spinning superparticle descriptions with Grassmann variables or with c-number spinors

International Nuclear Information System (INIS)

Barut, A.O.; Pavsic, M.

1988-05-01

A remarkable equivalence is established between the theories of spinning particles or superparticles using anticommuting Grassmann variables on the one hand and commuting c-number spinors on the other. We consider both real and complex Grassmann variables and map the equations of motion and the supersymmetry transformation from one theory to another. The more intuitive c-number theory allows us to generalize the notion of Zitterbewegung to strings and membranes. (A hidden supersymmetry exists in the classical model of the Dirac electron.) (author). 12 refs

Estimation of the number of wild pigs found in the United States

Energy Technology Data Exchange (ETDEWEB)

Mayer, J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2014-08-01

Based on a compilation of three estimation approaches, the total nationwide population of wild pigs in the United States numbers approximately 6.3 million animals, with that total estimate ranging from 4.4 up to 11.3 million animals. The majority of these numbers (99 percent), which were encompassed by ten states (i.e., Alabama, Arkansas, California, Florida, Georgia, Louisiana, Mississippi, Oklahoma, South Carolina and Texas), were based on defined estimation methodologies (e.g., density estimates correlated to the total potential suitable wild pig habitat statewide, statewide harvest percentages, statewide agency surveys regarding wild pig distribution and numbers). In contrast to the pre-1990 estimates, none of these more recent efforts, collectively encompassing 99 percent of the total, were based solely on anecdotal information or speculation. To that end, one can defensibly state that the wild pigs found in the United States number in the millions of animals, with the nationwide population estimated to arguably vary from about four million up to about eleven million individuals.

All ternary permutation constraint satisfaction problems parameterized above average have kernels with quadratic numbers of variables

DEFF Research Database (Denmark)

Gutin, Gregory; Van Iersel, Leo; Mnich, Matthias

2010-01-01

A ternary Permutation-CSP is specified by a subset Π of the symmetric group S3. An instance of such a problem consists of a set of variables V and a multiset of constraints, which are ordered triples of distinct variables of V. The objective is to find a linear ordering α of V that maximizes...... the number of triples whose rearrangement (under α) follows a permutation in Π. We prove that all ternary Permutation-CSPs parameterized above average have kernels with quadratic numbers of variables....

Glacier variability in the conterminous United States during the twentieth century

Science.gov (United States)

McCabe, Gregory J.; Fountain, Andrew G.

2013-01-01

Glaciers of the conterminous United States have been receding for the past century. Since 1900 the recession has varied from a 24 % loss in area (Mt. Rainier, Washington) to a 66 % loss in the Lewis Range of Montana. The rates of retreat are generally similar with a rapid loss in the early decades of the 20th century, slowing in the 1950s–1970s, and a resumption of rapid retreat starting in the 1990s. Decadal estimates of changes in glacier area for a subset of 31 glaciers from 1900 to 2000 are used to test a snow water equivalent model that is subsequently employed to examine the effects of temperature and precipitation variability on annual glacier area changes for these glaciers. Model results indicate that both winter precipitation and winter temperature have been important climatic factors affecting the variability of glacier variability during the 20th Century. Most of the glaciers analyzed appear to be more sensitive to temperature variability than to precipitation variability. However, precipitation variability is important, especially for high elevation glaciers. Additionally, glaciers with areas greater than 1 km2 are highly sensitive to variability in temperature.

Strong Laws of Large Numbers for Arrays of Rowwise NA and LNQD Random Variables

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Jiangfeng Wang

2011-01-01

Full Text Available Some strong laws of large numbers and strong convergence properties for arrays of rowwise negatively associated and linearly negative quadrant dependent random variables are obtained. The results obtained not only generalize the result of Hu and Taylor to negatively associated and linearly negative quadrant dependent random variables, but also improve it.

Sub-polyhedral scheduling using (unit-)two-variable-per-inequality polyhedra

OpenAIRE

Upadrasta , Ramakrishna; Cohen , Albert

2013-01-01

International audience; Polyhedral compilation has been successful in the design and implementation of complex loop nest optimizers and parallelizing compilers. The algorithmic complexity and scalability limitations remain one important weakness. We address it using sub-polyhedral under-aproximations of the systems of constraints resulting from affine scheduling problems. We propose a sub-polyhedral scheduling technique using (Unit-)Two-Variable-Per-Inequality or (U)TVPI Polyhedra. This techn...

Selection of Belt Conveyors Drive Units Number by Technical –Economical Analysis

OpenAIRE

Despodov, Zoran; Mijalkovski, Stojance; Adjiski, Vancho; Panov, Zoran

2014-01-01

In this paper is presented a methodology for selection of belt conveyor drive units number by technical - economical analysis of their parameters. Belt Conveyors with follow drive arrangement will be considered: one, two, three and four drive units. In the technical - economical analysis are including: Tension forces, Power of belt conveyor, Costs for belt, Costs for power and reducers, Total cost for belt conveyor system.

Brucella 'HOOF-Prints': strain typing by multi-locus analysis of variable number tandem repeats (VNTRs

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Halling Shirley M

2003-07-01

Full Text Available Abstract Background Currently, there are very few tools available for subtyping Brucella isolates for epidemiological trace-back. Subtyping is difficult because of the genetic homogeneity within the genus. Sequencing of the genomes from three Brucella species has facilitated the search for DNA sequence variability. Recently, hypervariability among short tandem repeat sequences has been exploited for strain-typing of several bacterial pathogens. Results An eight-base pair tandem repeat sequence was discovered in nine genomic loci of the B. abortus genome. Eight loci were hypervariable among the three Brucella species. A PCR-based method was developed to identify the number of repeat units (alleles at each locus, generating strain-specific fingerprints. None of the loci exhibited species- or biovar-specific alleles. Sometimes, a species or biovar contained a specific allele at one or more loci, but the allele also occurred in other species or biovars. The technique successfully differentiated the type strains for all Brucella species and biovars, among unrelated B. abortus biovar 1 field isolates in cattle, and among B. abortus strains isolated from bison and elk. Isolates from the same herd or from short-term in vitro passage exhibited little or no variability in fingerprint pattern. Sometimes, isolates from an animal would have multiple alleles at a locus, possibly from mixed infections in enzootic areas, residual disease from incomplete depopulation of an infected herd or molecular evolution within the strain. Therefore, a mixed population or a pool of colonies from each animal and/or tissue was tested. Conclusion This paper describes a new method for fingerprinting Brucella isolates based on multi-locus characterization of a variable number, eight-base pair, tandem repeat. We have named this technique "HOOF-Prints" for Hypervariable Octameric Oligonucleotide Finger-Prints. The technique is highly discriminatory among Brucella species, among

Estimating Composite Curve Number Using an Improved SCS-CN Method with Remotely Sensed Variables in Guangzhou, China

Directory of Open Access Journals (Sweden)

Qihao Weng

2013-03-01

Full Text Available The rainfall and runoff relationship becomes an intriguing issue as urbanization continues to evolve worldwide. In this paper, we developed a simulation model based on the soil conservation service curve number (SCS-CN method to analyze the rainfall-runoff relationship in Guangzhou, a rapid growing metropolitan area in southern China. The SCS-CN method was initially developed by the Natural Resources Conservation Service (NRCS of the United States Department of Agriculture (USDA, and is one of the most enduring methods for estimating direct runoff volume in ungauged catchments. In this model, the curve number (CN is a key variable which is usually obtained by the look-up table of TR-55. Due to the limitations of TR-55 in characterizing complex urban environments and in classifying land use/cover types, the SCS-CN model cannot provide more detailed runoff information. Thus, this paper develops a method to calculate CN by using remote sensing variables, including vegetation, impervious surface, and soil (V-I-S. The specific objectives of this paper are: (1 To extract the V-I-S fraction images using Linear Spectral Mixture Analysis; (2 To obtain composite CN by incorporating vegetation types, soil types, and V-I-S fraction images; and (3 To simulate direct runoff under the scenarios with precipitation of 57mm (occurred once every five years by average and 81mm (occurred once every ten years. Our experiment shows that the proposed method is easy to use and can derive composite CN effectively.

Optimized molecular resolution of cross-contamination alerts in clinical mycobacteriology laboratories

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de Viedma Darío

2008-02-01

Full Text Available Abstract Background The phenomenon of misdiagnosing tuberculosis (TB by laboratory cross-contamination when culturing Mycobacterium tuberculosis (MTB has been widely reported and it has an obvious clinical, therapeutic and social impact. The final confirmation of a cross-contamination event requires the molecular identification of the same MTB strain cultured from both the potential source of the contamination and from the false-positive candidate. The molecular tool usually applied in this context is IS6110-RFLP which takes a long time to provide an answer, usually longer than is acceptable for microbiologists and clinicians to make decisions. Our purpose in this study is to evaluate a novel PCR-based method, MIRU-VNTR as an alternative to assure a rapid and optimized analysis of cross-contamination alerts. Results MIRU-VNTR was prospectively compared with IS6110-RFLP for clarifying 19 alerts of false positivity from other laboratories. MIRU-VNTR highly correlated with IS6110-RFLP, reduced the response time by 27 days and clarified six alerts unresolved by RFLP. Additionally, MIRU-VNTR revealed complex situations such as contamination events involving polyclonal isolates and a false-positive case due to the simultaneous cross-contamination from two independent sources. Conclusion Unlike standard RFLP-based genotyping, MIRU-VNTR i could help reduce the impact of a false positive diagnosis of TB, ii increased the number of events that could be solved and iii revealed the complexity of some cross-contamination events that could not be dissected by IS6110-RFLP.

Intraspecific Variability of Rotylenchulus reniformis from Cotton-growing Regions in the United States

OpenAIRE

Agudelo, Paula; Robbins, Robert T.; Stewart, James McD.; Szalanski, Allen L.

2005-01-01

Reniform nematode (Rotylenchulus reniformis) is a major pest of cotton in the southeastern United States. The objective of this study was to examine the variation of reniform nematode populations from cotton-growing locations in the United States where it is prevalent. Multivariate analysis of variance and discriminant analysis were used to determine the variability of morphology in males and immature females. Reproduction indices of populations were measured on selected soybean and cotton ge...

Analysis on electronic control unit of continuously variable transmission

Science.gov (United States)

Cao, Shuanggui

Continuously variable transmission system can ensure that the engine work along the line of best fuel economy, improve fuel economy, save fuel and reduce harmful gas emissions. At the same time, continuously variable transmission allows the vehicle speed is more smooth and improves the ride comfort. Although the CVT technology has made great development, but there are many shortcomings in the CVT. The CVT system of ordinary vehicles now is still low efficiency, poor starting performance, low transmission power, and is not ideal controlling, high cost and other issues. Therefore, many scholars began to study some new type of continuously variable transmission. The transmission system with electronic systems control can achieve automatic control of power transmission, give full play to the characteristics of the engine to achieve optimal control of powertrain, so the vehicle is always traveling around the best condition. Electronic control unit is composed of the core processor, input and output circuit module and other auxiliary circuit module. Input module collects and process many signals sent by sensor and , such as throttle angle, brake signals, engine speed signal, speed signal of input and output shaft of transmission, manual shift signals, mode selection signals, gear position signal and the speed ratio signal, so as to provide its corresponding processing for the controller core.

Sequence determinants of human microsatellite variability

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Jakobsson Mattias

2009-12-01

Full Text Available Abstract Background Microsatellite loci are frequently used in genomic studies of DNA sequence repeats and in population studies of genetic variability. To investigate the effect of sequence properties of microsatellites on their level of variability we have analyzed genotypes at 627 microsatellite loci in 1,048 worldwide individuals from the HGDP-CEPH cell line panel together with the DNA sequences of these microsatellites in the human RefSeq database. Results Calibrating PCR fragment lengths in individual genotypes by using the RefSeq sequence enabled us to infer repeat number in the HGDP-CEPH dataset and to calculate the mean number of repeats (as opposed to the mean PCR fragment length, under the assumption that differences in PCR fragment length reflect differences in the numbers of repeats in the embedded repeat sequences. We find the mean and maximum numbers of repeats across individuals to be positively correlated with heterozygosity. The size and composition of the repeat unit of a microsatellite are also important factors in predicting heterozygosity, with tetra-nucleotide repeat units high in G/C content leading to higher heterozygosity. Finally, we find that microsatellites containing more separate sets of repeated motifs generally have higher heterozygosity. Conclusions These results suggest that sequence properties of microsatellites have a significant impact in determining the features of human microsatellite variability.

A Variable Turbulent Schmidt Number Formulation for Scramjet Application

Science.gov (United States)

Xiao, X.; Edwards, J. R.; Hassan, H. A.; Cutler, A. D.

2004-01-01

In high speed engines, thorough turbulent mixing of fuel and air is required to obtain high performance and high efficiency. Thus, the ability to predict turbulent mixing is crucial in obtaining accurate numerical simulation of an engine and its performance. Current state of the art in CFD simulation is to assume both turbulent Prandtl number and Schmidt numbers to be constants. However, since the mixing of fuel and air is inversely proportional to the Schmidt number, a value of 0.45 for the Schmidt number will produce twice as much diffusion as that with a value of 0.9. Because of this, current CFD tools and models have not been able to provide the needed guidance required for the efficient design of a scramjet engine. The goal of this investigation is to develop the framework needed to calculate turbulent Prandtl and Schmidt numbers as part of the solution. This requires four additional equations: two for the temperature variance and its dissipation rate and two for the concentration variance and its dissipation rate. In the current investigation emphasis will be placed on studying mixing without reactions. For such flows, variable Prandtl number does not play a major role in determining the flow. This, however, will have to be addressed when combustion is present. The approach to be used is similar to that used to develop the k-zeta model. In this approach, relevant equations are derived from the exact Navier-Stokes equations and each individual correlation is modeled. This ensures that relevant physics is incorporated into the model equations. This task has been accomplished. The final set of equations have no wall or damping functions. Moreover, they are tensorially consistent and Galilean invariant. The derivation of the model equations is rather lengthy and thus will not be incorporated into this abstract, but will be included in the final paper. As a preliminary to formulating the proposed model, the original k-zeta model with constant turbulent Prandtl and

A Simulation Based Analysis of Motor Unit Number Index (MUNIX) Technique Using Motoneuron Pool and Surface Electromyogram Models

Science.gov (United States)

Li, Xiaoyan; Rymer, William Zev; Zhou, Ping

2013-01-01

Motor unit number index (MUNIX) measurement has recently achieved increasing attention as a tool to evaluate the progression of motoneuron diseases. In our current study, the sensitivity of the MUNIX technique to changes in motoneuron and muscle properties was explored by a simulation approach utilizing variations on published motoneuron pool and surface electromyogram (EMG) models. Our simulation results indicate that, when keeping motoneuron pool and muscle parameters unchanged and varying the input motor unit numbers to the model, then MUNIX estimates can appropriately characterize changes in motor unit numbers. Such MUNIX estimates are not sensitive to different motor unit recruitment and rate coding strategies used in the model. Furthermore, alterations in motor unit control properties do not have a significant effect on the MUNIX estimates. Neither adjustment of the motor unit recruitment range nor reduction of the motor unit firing rates jeopardizes the MUNIX estimates. The MUNIX estimates closely correlate with the maximum M wave amplitude. However, if we reduce the amplitude of each motor unit action potential rather than simply reduce motor unit number, then MUNIX estimates substantially underestimate the motor unit numbers in the muscle. These findings suggest that the current MUNIX definition is most suitable for motoneuron diseases that demonstrate secondary evidence of muscle fiber reinnervation. In this regard, when MUNIX is applied, it is of much importance to examine a parallel measurement of motor unit size index (MUSIX), defined as the ratio of the maximum M wave amplitude to the MUNIX. However, there are potential limitations in the application of the MUNIX methods in atrophied muscle, where it is unclear whether the atrophy is accompanied by loss of motor units or loss of muscle fiber size. PMID:22514208

The effect of the number of seed variables on the performance of Cooke′s classical model

International Nuclear Information System (INIS)

Eggstaff, Justin W.; Mazzuchi, Thomas A.; Sarkani, Shahram

2014-01-01

In risk analysis, Cooke′s classical model for aggregating expert judgment has been widely used for over 20 years. However, the validity of this model has been the subject of much debate. Critics assert that this model′s scoring rule may unintentionally reward experts who manipulate their quantile estimates in order to receive a greater weight. In addition, the question of the number of seed variables required to ensure adequate performance of Cooke′s classical model remains unanswered. In this study, we conduct a comprehensive examination of the model through an iterative, cross validation test to perform an out-of-sample comparison between Cooke′s classical model and the equal-weight linear opinion pool method on almost all of the expert judgment studies compiled by Cooke and colleagues to date. Our results indicate that Cooke′s classical model significantly outperforms equally weighting expert judgment, regardless of the number of seed variables used; however, there may, in fact, be a maximum number of seed variables beyond which Cooke′s model cannot outperform an equally-weighted panel. - Highlights: • We examine Cooke′s classical model through an iterative, cross validation test. • The performance-based and equally weighted decision makers are compared. • Results strengthen Cooke′s argument for a two-fold cross-validation approach. • Accuracy test results show strong support in favor of Cooke′s classical method. • There may be a maximum number of seed variables that ensures model performance

TALGO BT - a variable gauge diesel driving unit for TALGO trains; TALGO BT - ein Diesel-Triebkopf mit variabler Spurweite fuer TALGO-Zuege

Energy Technology Data Exchange (ETDEWEB)

Zander, C.P. [Siemens Krauss-Maffei Lokomotiven GmbH, Muenchen (Germany)

2000-03-01

An adjustable driving unit was developed for the variable gauge TALGO trains which have been in use for decades. The unit also has a novel type of carriage and a novel braking system. [German] Fuer die seit Jahrzehnten im Einsatz befindlichen, spurwechselfaehigen TALGO-Zuege wurde ein umspurbarer Triebkopf entwickelt. Dieses Fahrzeug ist in mehrfacher Hinsicht ohne Vorbild. Neu sind neben dem spurveraenderlichen Drehgestell die Fahrwerksanordnung und das Bremssystem. (orig.)

Multiple-locus variable-number tandem repeat analysis of Neisseria meningitidis yields groupings similar to those obtained by multilocus sequence typing.

NARCIS (Netherlands)

Schouls, Leo M; Ende, Arie van der; Damen, Marjolein; Pol, Ingrid van de

2006-01-01

We identified many variable-number tandem repeat (VNTR) loci in the genomes of Neisseria meningitidis serogroups A, B, and C and utilized a number of these loci to develop a multiple-locus variable-number tandem repeat analysis (MLVA). Eighty-five N. meningitidis serogroup B and C isolates obtained

Influence of management of variables, sampling zones and land units on LR analysis for landslide spatial prevision

Directory of Open Access Journals (Sweden)

R. Greco

2013-09-01

Full Text Available Several authors, according to different methodological approaches, have employed logistic Regression (LR, a multivariate statistical analysis adopted to assess the spatial probability of landslide, even though its fundamental principles have remained unaltered. This study aims at assessing the influence of some of these methodological approaches on the performance of LR, through a series of sensitivity analyses developed over a test area of about 300 km2 in Calabria (southern Italy. In particular, four types of sampling (1 – the whole study area; 2 – transects running parallel to the general slope direction of the study area with a total surface of about 1/3 of the whole study area; 3 – buffers surrounding the phenomena with a 1/1 ratio between the stable and the unstable area; 4 – buffers surrounding the phenomena with a 1/2 ratio between the stable and the unstable area, two variable coding modes (1 – grouped variables; 2 – binary variables, and two types of elementary land (1 – cells units; 2 – slope units units have been tested. The obtained results must be considered as statistically relevant in all cases (Aroc values > 70%, thus confirming the soundness of the LR analysis which maintains high predictive capacities notwithstanding the features of input data. As for the area under investigation, the best performing methodological choices are the following: (i transects produced the best results (0 P(y ≤ 93.4%; Aroc = 79.5%; (ii as for sampling modalities, binary variables (0 P(y ≤ 98.3%; Aroc = 80.7% provide better performance than ordinated variables; (iii as for the choice of elementary land units, slope units (0 P(y ≤ 100%; Aroc = 84.2% have obtained better results than cells matrix.

Design of a propeller turbine with a variable revolution number; Entwicklung einer Propellerturbine mit variabler Drehzahl

Energy Technology Data Exchange (ETDEWEB)

Fella, G.; Wierer, C. [Fella GmbH Maschinen- und Apparatebau, Amorbach (Germany); Goede, E.; Batrekhy, S.; Ruprecht, A. [Stuttgart Univ. (Germany). Inst. fuer Stroemungsmechanik und Hydraulische Stroemungsmaschinen

1997-12-31

The small hydroelectric power station of Rupboden in the Oberfranken district was reactivated after having been decommissioned for 30 years. This new low pressure plant consists of an open-flume turbine with an adjustable diffusor and a firm rotor disk (propeller) with a vertical rod. A large range of operation at a constant height of fall is ensured by a variable revolution number. The profiles of the adjustable diffusor and rotor disk and the design of the draft tube were optimized using numerical flow calculation. First operating experience is very positive. The turbine runs extremely smoothly over the entire range. (orig.) [Deutsch] Das Kleinwasserkraftwerk Rupboden in Oberfanken wurde nach 30 Jahren Stillstand reaktiviert. Die neue Niederdruckanlage besteht aus einer Schachtturbine mit verstellbarem Leitapparat, feststehendem Laufrad (Propeller) mit senkrechter Welle. Zum Erzielen eines grossen Betriebsbereiches bei gleichbleibender Fallhoehe wurde eine variable Drehzahl vorgesehen. Die Profilierung von Leitapparat und Laufrad sowie die Formgebung fuer das Saugrohr wurden mit numerischer Stroemungsberechnung optimiert. Erste Betriebserfahrungen sind sehr positiv. Die Turbine laeuft im gesamten Leistungsbereich ausserordentlich ruhig. (orig.)

Study of Variable Turbulent Prandtl Number Model for Heat Transfer to Supercritical Fluids in Vertical Tubes

Science.gov (United States)

Tian, Ran; Dai, Xiaoye; Wang, Dabiao; Shi, Lin

2018-06-01

In order to improve the prediction performance of the numerical simulations for heat transfer of supercritical pressure fluids, a variable turbulent Prandtl number (Prt) model for vertical upward flow at supercritical pressures was developed in this study. The effects of Prt on the numerical simulation were analyzed, especially for the heat transfer deterioration conditions. Based on the analyses, the turbulent Prandtl number was modeled as a function of the turbulent viscosity ratio and molecular Prandtl number. The model was evaluated using experimental heat transfer data of CO2, water and Freon. The wall temperatures, including the heat transfer deterioration cases, were more accurately predicted by this model than by traditional numerical calculations with a constant Prt. By analyzing the predicted results with and without the variable Prt model, it was found that the predicted velocity distribution and turbulent mixing characteristics with the variable Prt model are quite different from that predicted by a constant Prt. When heat transfer deterioration occurs, the radial velocity profile deviates from the log-law profile and the restrained turbulent mixing then leads to the deteriorated heat transfer.

24 CFR 290.21 - Computing annual number of units eligible for substitution of tenant-based assistance or...

Science.gov (United States)

2010-04-01

... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Computing annual number of units eligible for substitution of tenant-based assistance or alternative uses. 290.21 Section 290.21 Housing and... Multifamily Projects § 290.21 Computing annual number of units eligible for substitution of tenant-based...

Evaluation of phase separator number in hydrodesulfurization (HDS) unit

Science.gov (United States)

Jayanti, A. D.; Indarto, A.

2016-11-01

The removal process of acid gases such as H2S in natural gas processing industry is required in order to meet sales gas specification. Hydrodesulfurization (HDS)is one of the processes in the refinery that is dedicated to reduce sulphur.InHDS unit, phase separator plays important role to remove H2S from hydrocarbons, operated at a certain pressure and temperature. Optimization of the number of separator performed on the system is then evaluated to understand the performance and economics. From the evaluation, it shows that all systems were able to meet the specifications of H2S in the desired product. However, one separator system resulted the highest capital and operational costs. The process of H2S removal with two separator systems showed the best performance in terms of both energy efficiency with the lowest capital and operating cost. The two separator system is then recommended as a reference in the HDS unit to process the removal of H2S from natural gas.

Variability common to first leaf dates and snowpack in the western conterminous United States

Science.gov (United States)

McCabe, Gregory J.; Betancourt, Julio L.; Pederson, Gregory T.; Schwartz, Mark D.

2013-01-01

Singular value decomposition is used to identify the common variability in first leaf dates (FLDs) and 1 April snow water equivalent (SWE) for the western United States during the period 1900–2012. Results indicate two modes of joint variability that explain 57% of the variability in FLD and 69% of the variability in SWE. The first mode of joint variability is related to widespread late winter–spring warming or cooling across the entire west. The second mode can be described as a north–south dipole in temperature for FLD, as well as in cool season temperature and precipitation for SWE, that is closely correlated to the El Niño–Southern Oscillation. Additionally, both modes of variability indicate a relation with the Pacific–North American atmospheric pattern. These results indicate that there is a substantial amount of common variance in FLD and SWE that is related to large-scale modes of climate variability.

Variability of the nucleoli number in the progenies of intact and UV-irradiated clonogenic Hela cells

International Nuclear Information System (INIS)

Kucheryavaya, N.A.; Zavol'naya, E.S.; Vakhtin, Yu.B.

1981-01-01

The coefficient of the ''nucleoli number'' character heritability (h 2 ) in the population of intact Hela cells equals 0.21 to 0.33. UV-irradiation enhances almost equally both the intraclonic and population variability of the nucleoli number and, as a result, the coefficient of the ''nucleoli number'' character heritability does not change in the population of UV-irradiated Hela cells

Genetic characterization of Mycobacterium tuberculosis in the West Bank, Palestinian Territories

Directory of Open Access Journals (Sweden)

Ereqat Suheir

2012-06-01

Full Text Available Abstract Background The World Health Organization (WHO declared human tuberculosis (TB a global health emergency and launched the “Global Plan to Stop Tuberculosis” which aims to save a million lives by 2015. Global control of TB is increasingly dependent on rapid and accurate genetic typing of species of the Mycobacterium tuberculosis (MTB complex including M. tuberculosis. The aim of this study was to identify and genetically characterize the MTB isolates circulating in the West Bank, Palestinian Territories. Genotyping of the MTB isolates from patients with pulmonary TB was carried out using two molecular genetic techniques, spoligotyping and mycobacterial interspersed repetitive units-variable number of tandem repeat (MIRU-VNTR supported by analysis of the MTB specific deletion 1 (TbD1. Findings A total of 17 MTB patterns were obtained from the 31 clinical isolates analyzed by spoligotyping; corresponding to 2 orphans and 15 shared-types (SITs. Fourteen SITs matched a preexisting shared-type in the SITVIT2 database, whereas a single shared-type SIT3348 was newly created. The most common spoligotyping profile was SIT53 (T1 variant, identified in 35.5 % of the TB cases studied. Genetic characterization of 22 clinical isolates via the 15 loci MIRU-VNTR typing distinguished 19 patterns. The 15-loci MIT144 and MIT145 were newly created within this study. Both methods determined the present of M. bovis strains among the isolates. Conclusions Significant diversity among the MTB isolates circulating in the West Bank was identified with SIT53-T1 genotype being the most frequent strain. Our results are used as reference database of the strains circulating in our region and may facilitate the implementation of an efficient TB control program.

First insight into the genotypic diversity of clinical Mycobacterium tuberculosis isolates from Gansu Province, China.

Directory of Open Access Journals (Sweden)

Jie Liu

Full Text Available BACKGROUND: Investigations of Mycobacterium tuberculosis genetic diversity in China have indicated a significant regional distribution. The aim of this study was to characterize the genotypes of clinical M. tuberculosis isolates obtained from Gansu, which has a special geographic location in China. METHODOLOGY/PRINCIPAL FINDINGS: A total of 467 clinical M. tuberculosis strains isolated in Gansu Province were genotyped by 15-locus mycobacterial interspersed repetitive units-variable number tandem repeats (MIRU-VNTR and spoligotyping. The results showed that 445 isolates belonged to six known spoligotype lineages, whereas 22 isolates were unknown. The Beijing genotype was the most prevalent (87.58%, n = 409, while the shared type 1 was the dominant genotype (80.94%, n = 378. The second most common lineage was the T lineage, with 25 isolates (5.35%, followed by the H lineage with 5 isolates (1.07%, the MANU family (0.64%, 3 isolates, the U family (0.43%, 2 isolates and the CAS lineage with 1 isolate (0.21%. By using the VNTR15China method, we observed 15 groups and 228 genotypes among the 467 isolates. We found no association between the five larger groups (including the Beijing genotype and sex, age, or treatment status, and there was no noticeable difference in the group analysis in different areas. In the present study, seven of the 15 MIRU-VNTR loci were highly or moderately discriminative according to their Hunter-Gaston discriminatory index. CONCLUSIONS/SIGNIFICANCE: The Beijing genotype is the predominant genotype in Gansu province. We confirm that VNTR15China is suitable for typing Beijing strains in China and that it has a better discriminatory power than spoligotyping. Therefore, the use of both methods is the most suitable for genotyping analysis of M. tuberculosis.

Criterion for the nuclearity of spaces of functions of infinite number of variables

International Nuclear Information System (INIS)

Gali, I.M.

1977-08-01

The paper formulates a new necessary and sufficient condition for the nuclearity of spaces of infinite number of variables, and defines new nuclear spaces which play an important role in the field of functional analysis and quantum field theory. Also the condition for nuclearity of the infinite weighted tensor product of nuclear spaces is given

Low numbers of repeat units in variable number of tandem repeats (VNTR) regions of white spot syndrome virus are correlated with disease outbreaks

NARCIS (Netherlands)

Tran Thi Tuyet, H.; Zwart, M.P.; Phuong, N.T.; Jong, de M.C.M.; Vlak, J.M.

2012-01-01

White spot syndrome virus (WSSV) is the most important pathogen in shrimp farming systems worldwide including the Mekong Delta, Vietnam. The genome of WSSV is characterized by the presence of two major 'indel regions' found at ORF14/15 and ORF23/24 (WSSV-Thailand) and three regions with variable

A medical admission unit reduces duration of hospital stay and number of readmissions

DEFF Research Database (Denmark)

Vork, Jan C; Brabrand, Mikkel; Folkestad, Lars

2011-01-01

Political initiatives promoting a more efficient emergency admission process have triggered a reorganisation of the Danish health system with a view to creating fewer and larger admission units counting more experienced physicians. At our hospital, a medical admission unit (MAU) was established. ...... present the effect of this on the length of hospital stay, mortality rates and the number of readmissions for the last year with the previous structure and the first year of the new MAU structure....

Motor unit number estimation in the quantitative assessment of severity and progression of motor unit loss in Hirayama disease.

Science.gov (United States)

Zheng, Chaojun; Zhu, Yu; Zhu, Dongqing; Lu, Feizhou; Xia, Xinlei; Jiang, Jianyuan; Ma, Xiaosheng

2017-06-01

To investigate motor unit number estimation (MUNE) as a method to quantitatively evaluate severity and progression of motor unit loss in Hirayama disease (HD). Multipoint incremental MUNE was performed bilaterally on both abductor digiti minimi and abductor pollicis brevis muscles in 46 patients with HD and 32 controls, along with handgrip strength examination. MUNE was re-evaluated approximately 1year after initial examination in 17 patients with HD. The MUNE values were significantly lower in all the tested muscles in the HD group (Pdisease duration (Pmotor unit loss in patients with HD within approximately 1year (P4years. A reduction in the functioning motor units was found in patients with HD compared with that in controls, even in the early asymptomatic stages. Moreover, the motor unit loss in HD progresses gradually as the disease advances. These results have provided evidence for the application of MUNE in estimating the reduction of motor unit in HD and confirming the validity of MUNE for tracking the progression of HD in a clinical setting. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

Unit Reynolds number, Mach number and pressure gradient effects on laminar-turbulent transition in two-dimensional boundary layers

Science.gov (United States)

Risius, Steffen; Costantini, Marco; Koch, Stefan; Hein, Stefan; Klein, Christian

2018-05-01

The influence of unit Reynolds number (Re_1=17.5× 106-80× 106 {m}^{-1}), Mach number (M= 0.35-0.77) and incompressible shape factor (H_{12} = 2.50-2.66) on laminar-turbulent boundary layer transition was systematically investigated in the Cryogenic Ludwieg-Tube Göttingen (DNW-KRG). For this investigation the existing two-dimensional wind tunnel model, PaLASTra, which offers a quasi-uniform streamwise pressure gradient, was modified to reduce the size of the flow separation region at its trailing edge. The streamwise temperature distribution and the location of laminar-turbulent transition were measured by means of temperature-sensitive paint (TSP) with a higher accuracy than attained in earlier measurements. It was found that for the modified PaLASTra model the transition Reynolds number (Re_{ {tr}}) exhibits a linear dependence on the pressure gradient, characterized by H_{12}. Due to this linear relation it was possible to quantify the so-called `unit Reynolds number effect', which is an increase of Re_{ {tr}} with Re_1. By a systematic variation of M, Re_1 and H_{12} in combination with a spectral analysis of freestream disturbances, a stabilizing effect of compressibility on boundary layer transition, as predicted by linear stability theory, was detected (`Mach number effect'). Furthermore, two expressions were derived which can be used to calculate the transition Reynolds number as a function of the amplitude of total pressure fluctuations, Re_1 and H_{12}. To determine critical N-factors, the measured transition locations were correlated with amplification rates, calculated by incompressible and compressible linear stability theory. By taking into account the spectral level of total pressure fluctuations at the frequency of the most amplified Tollmien-Schlichting wave at transition location, the scatter in the determined critical N-factors was reduced. Furthermore, the receptivity coefficients dependence on incidence angle of acoustic waves was used to

Variability of the nucleoli number in the progenies of intact and UV-irradiated clonogenic Hela cells

Energy Technology Data Exchange (ETDEWEB)

Kucheryavaya, N.A.; Zavol' naya, E.S.; Vakhtin, Yu.B. (AN SSSR, Leningrad. Inst. Tsitologii)

1981-01-01

The coefficient of the ''nucleoli number'' character heritability (h/sup 2/) in the population of intact Hela cells equals 0.21 to 0.33. UV-irradiation enhances almost equally both the intraclonic and population variability of the nucleoli number and, as a result, the coefficient of the ''nucleoli number'' character heritability does not change in the population of UV-irradiated Hela cells.

First worldwide proficiency study on variable-number tandem-repeat typing of Mycobacterium tuberculosis complex strains.

NARCIS (Netherlands)

Beer, J.L. de; Kremer, K.; Kodmon, C.; Supply, P.; Soolingen, D. van

2012-01-01

Although variable-number tandem-repeat (VNTR) typing has gained recognition as the new standard for the DNA fingerprinting of Mycobacterium tuberculosis complex (MTBC) isolates, external quality control programs have not yet been developed. Therefore, we organized the first multicenter proficiency

Impact of climate variability on runoff in the north-central United States

Science.gov (United States)

Ryberg, Karen R.; Lin, Wei; Vecchia, Aldo V.

2014-01-01

Large changes in runoff in the north-central United States have occurred during the past century, with larger floods and increases in runoff tending to occur from the 1970s to the present. The attribution of these changes is a subject of much interest. Long-term precipitation, temperature, and streamflow records were used to compare changes in precipitation and potential evapotranspiration (PET) to changes in runoff within 25 stream basins. The basins studied were organized into four groups, each one representing basins similar in topography, climate, and historic patterns of runoff. Precipitation, PET, and runoff data were adjusted for near-decadal scale variability to examine longer-term changes. A nonlinear water-balance analysis shows that changes in precipitation and PET explain the majority of multidecadal spatial/temporal variability of runoff and flood magnitudes, with precipitation being the dominant driver. Historical changes in climate and runoff in the region appear to be more consistent with complex transient shifts in seasonal climatic conditions than with gradual climate change. A portion of the unexplained variability likely stems from land-use change.

Bayesian framework for prediction of future number of failures from a single group of units in the field

International Nuclear Information System (INIS)

Ebrahimi, Nader

2009-01-01

This paper considers prediction of unknown number of failures in a future inspection of a group of in-service units based on number of failures observed from an earlier inspection. We develop a flexible Bayesian model and calculate Bayesian estimator for this unknown number and other quantities of interest. The paper also includes an illustration of our method in an example about heat exchanger. A main advantage of our approach is in its nonparametric nature. By nonparametric here we simply mean that no assumption is required about the failure time distribution of a unit

Variable-number tandem repeats as molecular markers for biotypes of Pasteuria ramosa in Daphnia spp.

Science.gov (United States)

Mouton, Laurence; Nong, Guang; Preston, James F; Ebert, Dieter

2007-06-01

Variable-number tandem repeats (VNTRs) have been identified in populations of Pasteuria ramosa, a castrating endobacterium of Daphnia species. The allelic polymorphisms at 14 loci in laboratory and geographically diverse soil samples showed that VNTRs may serve as biomarkers for the genetic characterization of P. ramosa isolates.

Identification of Variable-Number Tandem-Repeat (VNTR) Sequences in Acinetobacter baumannii and Interlaboratory Validation of an Optimized Multiple-Locus VNTR Analysis Typing Scheme▿†

Science.gov (United States)

Pourcel, Christine; Minandri, Fabrizia; Hauck, Yolande; D'Arezzo, Silvia; Imperi, Francesco; Vergnaud, Gilles; Visca, Paolo

2011-01-01

Acinetobacter baumannii is an important opportunistic pathogen responsible for nosocomial outbreaks, mostly occurring in intensive care units. Due to the multiplicity of infection sources, reliable molecular fingerprinting techniques are needed to establish epidemiological correlations among A. baumannii isolates. Multiple-locus variable-number tandem-repeat analysis (MLVA) has proven to be a fast, reliable, and cost-effective typing method for several bacterial species. In this study, an MLVA assay compatible with simple PCR- and agarose gel-based electrophoresis steps as well as with high-throughput automated methods was developed for A. baumannii typing. Preliminarily, 10 potential polymorphic variable-number tandem repeats (VNTRs) were identified upon bioinformatic screening of six annotated genome sequences of A. baumannii. A collection of 7 reference strains plus 18 well-characterized isolates, including unique types and representatives of the three international A. baumannii lineages, was then evaluated in a two-center study aimed at validating the MLVA assay and comparing it with other genotyping assays, namely, macrorestriction analysis with pulsed-field gel electrophoresis (PFGE) and PCR-based sequence group (SG) profiling. The results showed that MLVA can discriminate between isolates with identical PFGE types and SG profiles. A panel of eight VNTR markers was selected, all showing the ability to be amplified and good amounts of polymorphism in the majority of strains. Independently generated MLVA profiles, composed of an ordered string of allele numbers corresponding to the number of repeats at each VNTR locus, were concordant between centers. Typeability, reproducibility, stability, discriminatory power, and epidemiological concordance were excellent. A database containing information and MLVA profiles for several A. baumannii strains is available from http://mlva.u-psud.fr/. PMID:21147956

Association between the dopamine D4 receptor gene exon III variable number of tandem repeats and political attitudes in female Han Chinese.

Science.gov (United States)

Ebstein, Richard P; Monakhov, Mikhail V; Lu, Yunfeng; Jiang, Yushi; Lai, Poh San; Chew, Soo Hong

2015-08-22

Twin and family studies suggest that political attitudes are partially determined by an individual's genotype. The dopamine D4 receptor gene (DRD4) exon III repeat region that has been extensively studied in connection with human behaviour, is a plausible candidate to contribute to individual differences in political attitudes. A first United States study provisionally identified this gene with political attitude along a liberal-conservative axis albeit contingent upon number of friends. In a large sample of 1771 Han Chinese university students in Singapore, we observed a significant main effect of association between the DRD4 exon III variable number of tandem repeats and political attitude. Subjects with two copies of the 4-repeat allele (4R/4R) were significantly more conservative. Our results provided evidence for a role of the DRD4 gene variants in contributing to individual differences in political attitude particularly in females and more generally suggested that associations between individual genes, and neurochemical pathways, contributing to traits relevant to the social sciences can be provisionally identified. © 2015 The Author(s).

Association between the dopamine D4 receptor gene exon III variable number of tandem repeats and political attitudes in female Han Chinese

Science.gov (United States)

Ebstein, Richard P.; Monakhov, Mikhail V.; Lu, Yunfeng; Jiang, Yushi; Lai, Poh San; Chew, Soo Hong

2015-01-01

Twin and family studies suggest that political attitudes are partially determined by an individual's genotype. The dopamine D4 receptor gene (DRD4) exon III repeat region that has been extensively studied in connection with human behaviour, is a plausible candidate to contribute to individual differences in political attitudes. A first United States study provisionally identified this gene with political attitude along a liberal–conservative axis albeit contingent upon number of friends. In a large sample of 1771 Han Chinese university students in Singapore, we observed a significant main effect of association between the DRD4 exon III variable number of tandem repeats and political attitude. Subjects with two copies of the 4-repeat allele (4R/4R) were significantly more conservative. Our results provided evidence for a role of the DRD4 gene variants in contributing to individual differences in political attitude particularly in females and more generally suggested that associations between individual genes, and neurochemical pathways, contributing to traits relevant to the social sciences can be provisionally identified. PMID:26246555

Comparison of a Variable-Number Tandem-Repeat (VNTR) Method for Typing Mycobacterium avium with Mycobacterial Interspersed Repetitive-Unit-VNTR and IS1245 Restriction Fragment Length Polymorphism Typing▿ †

OpenAIRE

Inagaki, Takayuki; Nishimori, Kei; Yagi, Tetsuya; Ichikawa, Kazuya; Moriyama, Makoto; Nakagawa, Taku; Shibayama, Takami; Uchiya, Kei-ichi; Nikai, Toshiaki; Ogawa, Kenji

2009-01-01

Mycobacterium avium complex (MAC) infections are increasing annually in various countries, including Japan, but the route of transmission and pathophysiology of the infection remain unclear. Currently, a variable-number tandem-repeat (VNTR) typing method using the Mycobacterium avium tandem repeat (MATR) loci (MATR-VNTR) is employed in Japan for epidemiological studies using clinical isolates of M. avium. In this study, the usefulness of this MATR-VNTR typing method was compared with that of ...

Pseudo-random number generators for Monte Carlo simulations on ATI Graphics Processing Units

Science.gov (United States)

Demchik, Vadim

2011-03-01

Basic uniform pseudo-random number generators are implemented on ATI Graphics Processing Units (GPU). The performance results of the realized generators (multiplicative linear congruential (GGL), XOR-shift (XOR128), RANECU, RANMAR, RANLUX and Mersenne Twister (MT19937)) on CPU and GPU are discussed. The obtained speed up factor is hundreds of times in comparison with CPU. RANLUX generator is found to be the most appropriate for using on GPU in Monte Carlo simulations. The brief review of the pseudo-random number generators used in modern software packages for Monte Carlo simulations in high-energy physics is presented.

The transition matrix element Agq(N) of the variable flavor number scheme at O(α3s)

International Nuclear Information System (INIS)

Ablinger, J.; Hasselhuhn, A.; Schneider, C.; Manteuffel, A. von

2014-01-01

We calculate the massive operator matrix element A (3) gq (N) to 3-loop order in Quantum Chromodynamics at general values of the Mellin variable N. This is the first complete transition function needed in the variable flavor number scheme obtained at O(α 3 s ). A fist independent recalculation is performed for the contributions ∝ N F of the 3-loop anomalous dimension γ (2) gq (N).

The transition matrix element Agq(N) of the variable flavor number scheme at O(αs3)

International Nuclear Information System (INIS)

Ablinger, J.; Blümlein, J.; De Freitas, A.; Hasselhuhn, A.; Manteuffel, A. von; Round, M.; Schneider, C.; Wißbrock, F.

2014-01-01

We calculate the massive unpolarized operator matrix element A gq (3) (N) to 3-loop order in Quantum Chromodynamics at general values of the Mellin variable N. This is the first complete transition function needed in the variable flavor number scheme obtained at O(α s 3 ). A first independent recalculation is performed for the contributions ∝N F of the 3-loop anomalous dimension γ gq (2) (N)

Effect of Fluoride Mouthrinse and Toothpaste on Number of Streptococcal Colony Forming Units of Dental Plaque

Directory of Open Access Journals (Sweden)

SE Jabbarifar

2005-11-01

Full Text Available Background: Frequent topical fluoride therapy through toothpaste, mouthrinse, professional gels and solutions causes decrease in incidence, pause and repair of dental caries in the enamel. These mechanisms are done through penetration of fluoride ions (F- and their replacement with hydroxyl ions (OH- of hydroxyappatite of enamel, interfere with microbial metabolism of dental plaque and bacteriostatic effect on some cariogenic bacterial strains such as streptococci. The aim of this study was to examine the effect of fluoride mouthrinse and toothpaste on the number of streptococcal colony forming units of dental plaque. Methods: 62 children with 6-7 years old were put in two groups. Samples of dental plaque from each group were collected both before and after use of the fluoride mouthrinse and or toothpaste. The samples were cultured on blood agar to find the number of streptococcal colony forming units (CFU. The mean colony forming unit was compared inter and intra groups before and after application of Fluoride products. Results: The streptococcal CFU of dental plaque before and after use of the mouthrinse and toothpaste respectively was (1240±1367, 1253±1341.5 and (551±716, 898±1151. Statistically, the streptococcal CFU in each group before and after use of the toothpaste and mouthrinse was significantly different. Conclusion: The findings of this study indicated that the fluoride toothpaste and mouthrinse reduce number of streptococcal colony forming units of dental plaque. Also this reduction was not depended on level of (F- Ions, sort of vehicle of fluoride and frequent application of the fluoride mouthrinse and toothpaste. Keywords: fluoride mouthrinse, fluoride toothpaste, colony forming unit (CFU, streptococcus

On the strong law of large numbers for $\\varphi$-subgaussian random variables

OpenAIRE

Zajkowski, Krzysztof

2016-01-01

For $p\\ge 1$ let $\\varphi_p(x)=x^2/2$ if $|x|\\le 1$ and $\\varphi_p(x)=1/p|x|^p-1/p+1/2$ if $|x|>1$. For a random variable $\\xi$ let $\\tau_{\\varphi_p}(\\xi)$ denote $\\inf\\{a\\ge 0:\\;\\forall_{\\lambda\\in\\mathbb{R}}\\; \\ln\\mathbb{E}\\exp(\\lambda\\xi)\\le\\varphi_p(a\\lambda)\\}$; $\\tau_{\\varphi_p}$ is a norm in a space $Sub_{\\varphi_p}=\\{\\xi:\\;\\tau_{\\varphi_p}(\\xi)1$) there exist positive constants $c$ and $\\alpha$ such that for every natural number $n$ the following inequality $\\tau_{\\varphi_p}(\\sum_{i=1...

Inclusive B-meson hadroproduction in the general-mass variable-flavor-number scheme

Energy Technology Data Exchange (ETDEWEB)

Kniehl, B.A.; Kramer, G. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Schienbein, I. [Universite Joseph Fourier, Grenoble (France). Lab. de Physique Subatomique et de Cosmologie]|[CNRS/IN2P3, Inst. National Polytechnique de Grenoble (France); Spiesberger, H. [Johannes Gutenberg Univ., Mainz (Germany). Inst. fuer Physik

2007-05-15

We calculate the cross section for the inclusive hadroproduction of B mesons as a function of transverse momentum p{sub T} at next-to-leading order (NLO) in the general- mass variable-flavor-number scheme using realistic non-perturbative fragmentation functions that are obtained through a global fit to e{sup +}e{sup -} data from CERN LEP1 and SLAC SLC exploiting their universality and scaling violations. We find good agreement with recent p anti p data taken by the CDF Collaboration in run II at the Fermilab Tevatron. We also present comparisons with NLO results obtained in two other schemes. (orig.)

Design of ideal cascades of gas centrifuges with variable separation factors

International Nuclear Information System (INIS)

Olander, D.R.

1976-01-01

A method of designing ideal cascades in which the separation factor varies with stage number is presented and applied to centrifuges as separating units. The centrifuge is characterized by a performance function, which gives the separative power, optimized with respect to all internal variables, as a function of cut and throughput. For centrifuges with certain types of performance functions, variable-α ideal cascades can provide a product at a lower cost than the conventional ideal cascade in which the separation factor is independent of stage number

Drivers of Seasonal Variability in Marine Boundary Layer Aerosol Number Concentration Investigated Using a Steady State Approach

Science.gov (United States)

Mohrmann, Johannes; Wood, Robert; McGibbon, Jeremy; Eastman, Ryan; Luke, Edward

2018-01-01

Marine boundary layer (MBL) aerosol particles affect the climate through their interaction with MBL clouds. Although both MBL clouds and aerosol particles have pronounced seasonal cycles, the factors controlling seasonal variability of MBL aerosol particle concentration are not well constrained. In this paper an aerosol budget is constructed representing the effects of wet deposition, free-tropospheric entrainment, primary surface sources, and advection on the MBL accumulation mode aerosol number concentration (Na). These terms are then parameterized, and by assuming that on seasonal time scales Na is in steady state, the budget equation is rearranged to form a diagnostic equation for Na based on observable variables. Using data primarily collected in the subtropical northeast Pacific during the MAGIC campaign (Marine ARM (Atmospheric Radiation Measurement) GPCI (GCSS Pacific Cross-Section Intercomparison) Investigation of Clouds), estimates of both mean summer and winter Na concentrations are made using the simplified steady state model and seasonal mean observed variables. These are found to match well with the observed Na. To attribute the modeled difference between summer and winter aerosol concentrations to individual observed variables (e.g., precipitation rate and free-tropospheric aerosol number concentration), a local sensitivity analysis is combined with the seasonal difference in observed variables. This analysis shows that despite wintertime precipitation frequency being lower than summer, the higher winter precipitation rate accounted for approximately 60% of the modeled seasonal difference in Na, which emphasizes the importance of marine stratocumulus precipitation in determining MBL aerosol concentrations on longer time scales.

Optimal design of unit hydrographs using probability distribution and ...

Indian Academy of Sciences (India)

R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

optimization formulation is solved using binary-coded genetic algorithms. The number of variables to ... Unit hydrograph; rainfall-runoff; hydrology; genetic algorithms; optimization; probability ..... Application of the model. Data derived from the ...

Number and distribution of gay bathhouses in the United States and Canada.

Science.gov (United States)

Woods, William J; Tracy, Daniel; Binson, Diane

2003-01-01

Although gay bathhouses have been the subject of debate and some public health policy for decades, the relative number and geographic distribution of these establishments has not been described. As a result, it is easy to miss or ignore them in making public policy in response to discase prevention. No straightforward methodology for such a description is available, so we used a series of gay travel books, first published in 1965 by the Damron Company, to estimate this distribution in the United States and Canada. Each of the annual guides published from 1968 to 1999 were reviewed for listings of bathhouses and sex clubs. The results suggest that bathhouses and other similar establishments exist in most states and provinces and in most large and many moderate-sized cities. Furthermore, the largest numbers of listings for bathhouses were in the same six cities across the decades, three in the U.S. and three in Canada. The greatest change in the number of listings was seen in the three U.S. cities where a public policy of closure was attempted. Nevertheless, the numbers of venues in these three cities have been increasing again since the early 1990s, although nothing near the numbers of listings in the late 1970s and early 1980s.

How variable is the number of triggered aftershocks?

Science.gov (United States)

Marsan, D.; Helmstetter, A.

2017-07-01

Aftershock activity depends at first order on the main shock magnitude but also shows important fluctuations between shocks of equal magnitude. We here investigate these fluctuations, by quantifying them and by relating them to the main shock stress drop and other variables, for southern California earthquakes. A method is proposed in order to only count directly triggered aftershocks, rather than secondary aftershocks (i.e., triggered by previous aftershocks), and to only quantify fluctuations going beyond the natural Poisson variability. Testing of the method subjected to various model errors allows to quantify its robustness. It is found that these fluctuations follow a distribution that is well fitted by a lognormal distribution, with a coefficient of variation of about 1.0 to 1.1. A simple model is proposed to relate this observed dependence to main shock stress drop variability.

Stratification of a cityscape using census and land use variables for inventory of building materials

Science.gov (United States)

Rosenfield, G.H.; Fitzpatrick-Lins, K.; Johnson, T.L.

1987-01-01

A cityscape (or any landscape) can be stratified into environmental units using multiple variables of information. For the purposes of sampling building materials, census and land use variables were used to identify similar strata. In the Metropolitan Statistical Area of a cityscape, the census tract is the smallest unit for which census data are summarized and digitized boundaries are available. For purposes of this analysis, census data on total population, total number of housing units, and number of singleunit dwellings were aggregated into variables of persons per square kilometer and proportion of housing units in single-unit dwellings. The level 2 categories of the U.S. Geological Survey's land use and land cover data base were aggregated into variables of proportion of residential land with buildings, proportion of nonresidential land with buildings, and proportion of open land. The cityscape was stratified, from these variables, into environmental strata of Urban Central Business District, Urban Livelihood Industrial Commercial, Urban Multi-Family Residential, Urban Single Family Residential, Non-Urban Suburbanizing, and Non-Urban Rural. The New England region was chosen as a region with commonality of building materials, and a procedure developed for trial classification of census tracts into one of the strata. Final stratification was performed by discriminant analysis using the trial classification and prior probabilities as weights. The procedure was applied to several cities, and the results analyzed by correlation analysis from a field sample of building materials. The methodology developed for stratification of a cityscape using multiple variables has application to many other types of environmental studies, including forest inventory, hydrologic unit management, waste disposal, transportation studies, and other urban studies. Multivariate analysis techniques have recently been used for urban stratification in England. ?? 1987 Annals of Regional

Three loop contributions to the matrix elements in the variable flavor number scheme

Energy Technology Data Exchange (ETDEWEB)

Bluemlein, Johannes; Hasselhuhn, Alexander [DESY (Germany); Schneider, Carsten [RISC, JKU Linz (Austria)

2012-07-01

The variable flavor number scheme may be used to describe parton distributions in the transition region in which one heavy quark gradually becomes a light flavor. We present first three-loop results to the massive operator matrix elements A{sub gg} and A{sub gq} for the contributions due to bubble topologies {proportional_to}T{sub F}{sup 2} n{sub f} at general values of the Mellin variable N. The calculation has been performed using higher transcendental functions and by applying modern summation technologies encoded in the package Sigma. These massive operator matrix elements describe the universal contributions in the matching of different flavor sectors, which are the logarithmic and constant contributions in the ratio of m{sup 2}{sub H}/Q{sup 2}, with Q{sup 2} the virtuality and m{sub H} the respective heavy quark mass. The framework allows to derive heavy quark parton distributions which are of relevance for calculating specific processes at hadron-hadron colliders.

A novel approach for evaluating the impact of fixed variables on photovoltaic (PV) solar installations using enhanced meta data analysis among higher education institutions in the United States

Science.gov (United States)

De Hoyos, Diane N.

The global demand for electric energy has continuously increased over the last few decades. Some mature, alternative generation methods are wind, power, photovoltaic panels, biogas and fuel cells. In order to find alternative sources of energy to aid in the reduction of our nation's dependency on non-renewable fuels, energy sources include the use of solar energy panels. The intent of these initiatives is to provide substantial energy savings and reduce dependence on the electrical grid and net metering savings during the peak energy-use hours. The focus of this study explores and provides a clearer picture of the adoption of solar photovoltaic technology in institutions of higher education. It examines the impact of different variables associated with a photovoltaic installation in an institutions of higher education in the United States on the production generations for universities. Secondary data was used with permission from the Advancement of Suitability in Higher Education (AASHE). A multiple regression analysis was performed to determine the impact of different variables on the energy generation production. A Meta Data transformation analysis offered a deeper investigation into the impact of the variables on the photovoltaic installations. Although a review of a significant number of journal articles, dissertations and thesis in the area of photovoltaic solar installations are available, there were limited studies of actual institutions of higher education with the significant volume of institutions. However a study where the database included a significant number of data variables is unique and provides a researcher the opportunity to investigate different facets of a solar installation. The data of the installations ranges from 1993-2015. Included in this observation are the researcher's experience both in the procurement industry and as a team member of a solar institution of higher education in the southern portion of the United States.

Correlation of Metabolic Variables with the Number of ORFs in Human Pathogenic and Phylogenetically Related Non- or Less-Pathogenic Bacteria.

Science.gov (United States)

Brambila-Tapia, Aniel Jessica Leticia; Poot-Hernández, Augusto Cesar; Garcia-Guevara, Jose Fernando; Rodríguez-Vázquez, Katya

2016-06-01

To date, a few works have performed a correlation of metabolic variables in bacteria; however specific correlations with these variables have not been reported. In this work, we included 36 human pathogenic bacteria and 18 non- or less-pathogenic-related bacteria and obtained all metabolic variables, including enzymes, metabolic pathways, enzymatic steps and specific metabolic pathways, and enzymatic steps of particular metabolic processes, from a reliable metabolic database (KEGG). Then, we correlated the number of the open reading frames (ORF) with these variables and with the proportions of these variables, and we observed a negative correlation with the proportion of enzymes (r = -0.506, p < 0.0001), metabolic pathways (r = -0.871, p < 00.0001), enzymatic reactions (r = -0.749, p < 00.0001), and with the proportions of central metabolism variables as well as a positive correlation with the proportions of multistep reactions (r = 0.650, p < 00.0001) and secondary metabolism variables. The proportion of multifunctional reactions (r: -0.114, p = 0.41) and the proportion of enzymatic steps (r: -0.205, p = 0.14) did not present a significant correlation. These correlations indicate that as the size of a genome (measured in the number of ORFs) increases, the proportion of genes that encode enzymes significantly diminishes (especially those related to central metabolism), suggesting that when essential metabolic pathways are complete, an increase in the number of ORFs does not require a similar increase in the metabolic pathways and enzymes, but only a slight increase is sufficient to cope with a large genome.

Modeling number of bacteria per food unit in comparison to bacterial concentration in quantitative risk assessment: impact on risk estimates.

Science.gov (United States)

Pouillot, Régis; Chen, Yuhuan; Hoelzer, Karin

2015-02-01

When developing quantitative risk assessment models, a fundamental consideration for risk assessors is to decide whether to evaluate changes in bacterial levels in terms of concentrations or in terms of bacterial numbers. Although modeling bacteria in terms of integer numbers may be regarded as a more intuitive and rigorous choice, modeling bacterial concentrations is more popular as it is generally less mathematically complex. We tested three different modeling approaches in a simulation study. The first approach considered bacterial concentrations; the second considered the number of bacteria in contaminated units, and the third considered the expected number of bacteria in contaminated units. Simulation results indicate that modeling concentrations tends to overestimate risk compared to modeling the number of bacteria. A sensitivity analysis using a regression tree suggests that processes which include drastic scenarios consisting of combinations of large bacterial inactivation followed by large bacterial growth frequently lead to a >10-fold overestimation of the average risk when modeling concentrations as opposed to bacterial numbers. Alternatively, the approach of modeling the expected number of bacteria in positive units generates results similar to the second method and is easier to use, thus potentially representing a promising compromise. Published by Elsevier Ltd.

Does Black’s Hypothesis for Output Variability Hold for Mexico?

OpenAIRE

Macri, Joseph; Sinha, Dipendra

2007-01-01

Using two data series, namely GDP and the index of industrial production, we study the relationship between output variability and the growth rate of output. Ng-Perron unit root test shows that the growth rate of GDP is non-stationary but the growth rate of industrial output is stationary. Thus, we use the ARCH-M model for the monthly data of industrial output. A number of specifications (with and without a dummy variable) are used. In all cases, the results show that output variability has a...

MULTIPLE-LOCUS VARIABLE-NUMBER TANDEM REPEAT ANALYSIS OF BRUCELLA ISOLATES FROM THAILAND.

Science.gov (United States)

Kumkrong, Khurawan; Chankate, Phanita; Tonyoung, Wittawat; Intarapuk, Apiradee; Kerdsin, Anusak; Kalambaheti, Thareerat

2017-01-01

Brucellosis-induced abortion can result in significant economic loss to farm animals. Brucellosis can be transmitted to humans during slaughter of infected animals or via consumption of contaminated food products. Strain identification of Brucella isolates can reveal the route of transmission. Brucella strains were isolated from vaginal swabs of farm animal, cow milk and from human blood cultures. Multiplex PCR was used to identify Brucella species, and owing to high DNA homology among Brucella isolates, multiple-locus variable-number tandem repeat analysis (MLVA) based on the number of tandem repeats at 16 different genomic loci was used for strain identification. Multiplex PCR categorized the isolates into B. abortus (n = 7), B. melitensis (n = 37), B. suis (n = 3), and 5 of unknown Brucella spp. MLVA-16 clustering analysis differentiated the strains into various genotypes, with Brucella isolates from the same geographic region being closely related, and revealed that the Thai isolates were phylogenetically distinct from those in other countries, including within the Southeast Asian region. Thus, MLVA-16 typing has utility in epidemiological studies.

Energy sensitivity and variability analysis of Populus hybrid short-rotation plantations in northeastern United States. Final report

Energy Technology Data Exchange (ETDEWEB)

Bowersox, T.W.; Blankenhorn, P.R.

1979-10-24

Production of biomass by corn-like plantations has been demonstrated by a number of researchers. These forest analogs of agronomic cropping systems have the potential to yield substantially more biomass per unit area than traditional forests. Care is needed in choosing the appropriate sites, species, spacing, and harvesting strategies. Opportunities for increased yields have been suggested for fertilization and irrigation. Utilization of the biomass from these dense plantations for energy was the focus of this study. Although the amount of energy potential of the biomass is important, the energy output must be greater than the energy input for biomass to have a positive benefit to society. Further, in order to completely evaluate the net energy of the system it is necessary to examine the energy out-to-in ratios on the basis of usable energy (for example, usable heat, process steam and electricity), as well as all of the energies expended in producing, harvesting, transporting and processing the biomass. The objective of this study is to establish and analyze the energy inputs for selected management strategies in order to evaluate the sensitivity and variability of the energy inputs in the net energy analysis, and based on the net energy analysis to recommend a management strategy that minimizes energy inputs while maximizing biomass yield for short-rotation systems of Populus spp. in the northeastern United States.

The Role of Equivalence and Order Relations in the Development and Coordination of the Concepts of Unit Size and Number of Units in Selected Conservation Type Measurement Problems.

Science.gov (United States)

Carpenter, Thomas P.

The major purpose of this study was 1) to investigate the development of the concept of a unit of measure and the coordination of unit size and the number of units 2) to relate this development to the development of conservation and 3) to determine the role of equivalence and nonequivalence relations in certain conservation and measurement…

Relative spatial soil geochemical variability along two transects across the United States and Canada

Science.gov (United States)

Garrett, Robert G.

2009-01-01

To support the development of protocols for the proposed North American Soil Geochemical Landscapes project, whose objective is to establish baselines for the geochemistry of North American soils, two continental-scale transects across the United States and Canada were sampled in 2004. The sampling employed a spatially stratified random sampling design in order to estimate the variability between 40-km linear sampling units, within them, at sample sites, and due to sample preparation and analytical chemical procedures. The 40-km scale was chosen to be consistent with the density proposed for the continental-scale project. The two transects, north–south (N–S) from northern Manitoba to the USA–Mexico border near El Paso, Texas, and east–west (E–W) from the Virginia shore north of Washington, DC, to north of San Francisco, California, closely following the 38th parallel, have been studied individually. The purpose of this study was to determine if statistically significant systematic spatial variation occurred along the transects. Data for 38 major, minor and trace elements in A- and C-horizon soils where less than 5% of the data were below the detection limit were investigated by Analysis of Variance (ANOVA). A total of 15 elements (K, Na, As, Ba, Be, Ce, La, Mn, Nb, P, Rb, Sb, Th, Tl and W) demonstrated statistically significant (p<0.05) variability at the between-40-km scale for both horizons along both transects. Only Cu failed to demonstrate significant variability at the between-40-km scale for both soil horizons along both transects.

Relations between zero-inflated variables in trials with horticultural crops

Directory of Open Access Journals (Sweden)

Alessandro D. Lúcio

2016-06-01

Full Text Available Certain characteristics of some vegetable crops allow multiple harvests during the production cycle; however, to our knowledge, no study has described the behavior of fruit production with progression of the production cycle in vegetable crops with multiple harvests that present data overdispersion. We aimed to characterize the data overdispersion of zero-inflated variables and identify the behavior of these variables during the production cycle of several vegetable crops with multiple harvests. Data from 11 uniformity trials were used without applying treatments; these comprise the database from the Experimental Plants Group at the Federal University of Santa Maria, Brazil. The trials were conducted using four horticultural species grown during different cultivation seasons, cultivation environments, and experimental structures. Although at each harvest, a larger number of basic units with harvest fruit was observed than units without harvest fruit, the basic unit percentage without fruit was high, generating an overdispersion within each individual harvest. The variability within each harvest was high and increased with the evolution of the production cycle of Capsicum annuum, Solanum lycopersicum var. cerasiforme, Phaseolus vulgaris, and Cucurbita pepo species. However, the correlation coefficient between the mean weight and number of harvest fruits tended to remain constant during the crop production cycle. These behaviors show that harvest management should be done individually, at each harvest, such that data overdispersion is reduced.

Relations between zero-inflated variables in trials with horticultural crops

Energy Technology Data Exchange (ETDEWEB)

Lúcio, A.D.; Nunes, L.F.; Rego, F.; Pasini, M.P.B.

2016-11-01

Certain characteristics of some vegetable crops allow multiple harvests during the production cycle; however, to our knowledge, no study has described the behavior of fruit production with progression of the production cycle in vegetable crops with multiple harvests that present data overdispersion. We aimed to characterize the data overdispersion of zero-inflated variables and identify the behavior of these variables during the production cycle of several vegetable crops with multiple harvests. Data from 11 uniformity trials were used without applying treatments; these comprise the database from the Experimental Plants Group at the Federal University of Santa Maria, Brazil. The trials were conducted using four horticultural species grown during different cultivation seasons, cultivation environments, and experimental structures. Although at each harvest, a larger number of basic units with harvest fruit was observed than units without harvest fruit, the basic unit percentage without fruit was high, generating an overdispersion within each individual harvest. The variability within each harvest was high and increased with the evolution of the production cycle of Capsicum annuum, Solanum lycopersicum var. cerasiforme, Phaseolus vulgaris, and Cucurbita pepo species. However, the correlation coefficient between the mean weight and number of harvest fruits tended to remain constant during the crop production cycle. These behaviors show that harvest management should be done individually, at each harvest, such that data overdispersion is reduced. (Author)

Characterization of the variable-number tandem repeats in vrrA from different Bacillus anthracis isolates

Energy Technology Data Exchange (ETDEWEB)

Jackson, P.J.; Walthers, E.A.; Richmond, K.L. [Los Alamos National Lab., NM (United States)] [and others

1997-04-01

PCR analysis of 198 Bacillus anthracis isolates revealed a variable region of DNA sequence differing in length among the isolates. Five Polymorphisms differed by the presence Of two to six copies of the 12-bp tandem repeat 5{prime}-CAATATCAACAA-3{prime}. This variable-number tandem repeat (VNTR) region is located within a larger sequence containing one complete open reading frame that encodes a putative 30-kDa protein. Length variation did not change the reading frame of the encoded protein and only changed the copy number of a 4-amino-acid sequence (QYQQ) from 2 to 6. The structure of the VNTR region suggests that these multiple repeats are generated by recombination or polymerase slippage. Protein structures predicted from the reverse-translated DNA sequence suggest that any structural changes in the encoded protein are confined to the region encoded by the VNTR sequence. Copy number differences in the VNTR region were used to define five different B. anthracis alleles. Characterization of 198 isolates revealed allele frequencies of 6.1, 17.7, 59.6, 5.6, and 11.1% sequentially from shorter to longer alleles. The high degree of polymorphism in the VNTR region provides a criterion for assigning isolates to five allelic categories. There is a correlation between categories and geographic distribution. Such molecular markers can be used to monitor the epidemiology of anthrax outbreaks in domestic and native herbivore populations. 22 refs., 4 figs., 3 tabs.

Population Structure among Mycobacterium tuberculosis Isolates from Pulmonary Tuberculosis Patients in Colombia

Science.gov (United States)

Realpe, Teresa; Correa, Nidia; Rozo, Juan Carlos; Ferro, Beatriz Elena; Gomez, Verónica; Zapata, Elsa; Ribon, Wellman; Puerto, Gloria; Castro, Claudia; Nieto, Luisa María; Diaz, Maria Lilia; Rivera, Oriana; Couvin, David; Rastogi, Nalin; Arbelaez, Maria Patricia; Robledo, Jaime

2014-01-01

Background Phylogeographic composition of M. tuberculosis populations reveals associations between lineages and human populations that might have implications for the development of strategies to control the disease. In Latin America, lineage 4 or the Euro-American, is predominant with considerable variations among and within countries. In Colombia, although few studies from specific localities have revealed differences in M. tuberculosis populations, there are still areas of the country where this information is lacking, as is a comparison of Colombian isolates with those from the rest of the world. Principal Findings A total of 414 M. tuberculosis isolates from adult pulmonary tuberculosis cases from three Colombian states were studied. Isolates were genotyped using IS6110-restriction fragment length polymorphism (RFLP), spoligotyping, and 24-locus Mycobacterial interspersed repetitive units variable number tandem repeats (MIRU-VNTRs). SIT42 (LAM9) and SIT62 (H1) represented 53.3% of isolates, followed by 8.21% SIT50 (H3), 5.07% SIT53 (T1), and 3.14% SIT727 (H1). Composite spoligotyping and 24-locus MIRU- VNTR minimum spanning tree analysis suggest a recent expansion of SIT42 and SIT62 evolved originally from SIT53 (T1). The proportion of Haarlem sublineage (44.3%) was significantly higher than that in neighboring countries. Associations were found between M. tuberculosis MDR and SIT45 (H1), as well as HIV-positive serology with SIT727 (H1) and SIT53 (T1). Conclusions This study showed the population structure of M. tuberculosis in several regions from Colombia with a dominance of the LAM and Haarlem sublineages, particularly in two major urban settings (Medellín and Cali). Dominant spoligotypes were LAM9 (SIT 42) and Haarlem (SIT62). The proportion of the Haarlem sublineage was higher in Colombia compared to that in neighboring countries, suggesting particular conditions of co-evolution with the corresponding human population that favor the success of this

Finding Solvable Units of Variables in Nonlinear ODEs of ECM Degradation Pathway Network

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Shuji Kawasaki

2017-01-01

Full Text Available We consider ordinary differential equation (ODE model for a pathway network that arises in extracellular matrix (ECM degradation. For solving the ODEs, we propose applying the mass conservation law (MCL, together with a stoichiometry called doubling rule, to them. Then it leads to extracting new units of variables in the ODEs that can be solved explicitly, at least in principle. The simulation results for the ODE solutions show that the numerical solutions are indeed in good accord with theoretical solutions and satisfy the MALs.

Finding Solvable Units of Variables in Nonlinear ODEs of ECM Degradation Pathway Network.

Science.gov (United States)

Kawasaki, Shuji; Minerva, Dhisa; Itano, Keiko; Suzuki, Takashi

2017-01-01

We consider ordinary differential equation (ODE) model for a pathway network that arises in extracellular matrix (ECM) degradation. For solving the ODEs, we propose applying the mass conservation law (MCL), together with a stoichiometry called doubling rule , to them. Then it leads to extracting new units of variables in the ODEs that can be solved explicitly, at least in principle. The simulation results for the ODE solutions show that the numerical solutions are indeed in good accord with theoretical solutions and satisfy the MALs.

Investigating the Variability in Cumulus Cloud Number as a Function of Subdomain Size and Organization using large-domain LES

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Neggers, R.

2017-12-01

Recent advances in supercomputing have introduced a "grey zone" in the representation of cumulus convection in general circulation models, in which this process is partially resolved. Cumulus parameterizations need to be made scale-aware and scale-adaptive to be able to conceptually and practically deal with this situation. A potential way forward are schemes formulated in terms of discretized Cloud Size Densities, or CSDs. Advantages include i) the introduction of scale-awareness at the foundation of the scheme, and ii) the possibility to apply size-filtering of parameterized convective transport and clouds. The CSD is a new variable that requires closure; this concerns its shape, its range, but also variability in cloud number that can appear due to i) subsampling effects and ii) organization in a cloud field. The goal of this study is to gain insight by means of sub-domain analyses of various large-domain LES realizations of cumulus cloud populations. For a series of three-dimensional snapshots, each with a different degree of organization, the cloud size distribution is calculated in all subdomains, for a range of subdomain sizes. The standard deviation of the number of clouds of a certain size is found to decrease with the subdomain size, following a powerlaw scaling corresponding to an inverse-linear dependence. Cloud number variability also increases with cloud size; this reflects that subsampling affects the largest clouds first, due to their typically larger neighbor spacing. Rewriting this dependence in terms of two dimensionless groups, by dividing by cloud number and cloud size respectively, yields a data collapse. Organization in the cloud field is found to act on top of this primary dependence, by enhancing the cloud number variability at the smaller sizes. This behavior reflects that small clouds start to "live" on top of larger structures such as cold pools, favoring or inhibiting their formation (as illustrated by the attached figure of cloud mask

Eccentric muscle damage has variable effects on motor unit recruitment thresholds and discharge patterns in elbow flexor muscles.

Science.gov (United States)

Dartnall, Tamara J; Rogasch, Nigel C; Nordstrom, Michael A; Semmler, John G

2009-07-01

The purpose of this study was to determine the effect of eccentric muscle damage on recruitment threshold force and repetitive discharge properties of low-threshold motor units. Ten subjects performed four tasks involving isometric contraction of elbow flexors while electromyographic (EMG) data were recorded from human biceps brachii and brachialis muscles. Tasks were 1) maximum voluntary contraction (MVC); 2) constant-force contraction at various submaximal targets; 3) motor unit recruitment threshold task; and 4) minimum motor unit discharge rate task. These tasks were performed on three separate days before, immediately after, and 24 h after eccentric exercise of elbow flexor muscles. MVC force declined (42%) immediately after exercise and remained depressed (29%) 24 h later, indicative of muscle damage. Mean motor unit recruitment threshold for biceps brachii was 8.4+/-4.2% MVC, (n=34) before eccentric exercise, and was reduced by 41% (5.0+/-3.0% MVC, n=34) immediately after and by 39% (5.2+/-2.5% MVC, n=34) 24 h after exercise. No significant changes in motor unit recruitment threshold were observed in the brachialis muscle. However, for the minimum tonic discharge rate task, motor units in both muscles discharged 11% faster (10.8+/-2.0 vs. 9.7+/-1.7 Hz) immediately after (n=29) exercise compared with that before (n=32). The minimum discharge rate variability was greater in brachialis muscle immediately after exercise (13.8+/-3.1%) compared with that before (11.9+/-3.1%) and 24 h after exercise (11.7+/-2.4%). No significant changes in minimum discharge rate variability were observed in the biceps brachii motor units after exercise. These results indicate that muscle damage from eccentric exercise alters motor unit recruitment thresholds for >or=24 h, but the effect is not the same in the different elbow flexor muscles.

Genotyping analysis of Helicobacter pylori using multiple-locus variable-number tandem-repeats analysis in five regions of China and Japan

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Zhang Jinyong

2011-09-01

Full Text Available Abstract Background H. pylori (Helicobacter pylori is the major causative agent of chronic active gastritis. The population of H. pylori shows a high genomic variability among isolates. And the polymorphism of repeat-units of genomics had participated the important process of evolution. Its long term colonization of the stomach caused different clinical outcomes, which may relate to the high degree of genetic variation of H. pylori. A variety of molecular typing tools have been developed to access genetic relatedness in H. pylori isolates. However, there is still no standard genotyping system of this bacterium. The MLVA (Multi-locus of variable number of tandem repeat analysis method is useful for performing phylogenetic analysis and is widely used in bacteria genotyping; however, there's little application in H. pylori analysis. This article is the first application of the MLVA method to investigate H. pylori from different districts and ethnic groups of China. Results MLVA of 12 VNTR loci with high discrimination power based on 30 candidates were performed on a collection of 202 strains of H. pylori which originated from five regions of China and Japan. Phylogenetic tree was constructed using MLVA profiles. 12 VNTR loci presented with high various polymorphisms, and the results demonstrated very close relationships between genotypes and ethnic groups. Conclusions This study used MLVA methodology providing a new perspective on the ethnic groups and distribution characteristics of H. pylori.

Temporal and spatial variability of wind resources in the United States as derived from the Climate Forecast System Reanalysis

Science.gov (United States)

Lejiang Yu; Shiyuan Zhong; Xindi Bian; Warren E. Heilman

2015-01-01

This study examines the spatial and temporal variability of wind speed at 80m above ground (the average hub height of most modern wind turbines) in the contiguous United States using Climate Forecast System Reanalysis (CFSR) data from 1979 to 2011. The mean 80-m wind exhibits strong seasonality and large spatial variability, with higher (lower) wind speeds in the...

Seasonal, Spatial, and Long-term Variability of Fine Mineral Dust in the United States

Science.gov (United States)

Hand, J. L.; White, W. H.; Gebhart, K. A.; Hyslop, N. P.; Gill, T. E.; Schichtel, B. A.

2017-12-01

Characterizing the seasonal, spatial, and long-term variability of fine mineral dust (FD) is important to assess its environmental and climate impacts. FD concentrations (mineral particles with aerodynamic diameters less than 2.5 µm) were estimated using ambient, ground-based PM2.5 elemental chemistry data from over 160 remote and rural Interagency Monitoring of Protected Visual Environments (IMPROVE) sites from 2011 through 2015. FD concentrations were highest and contributed over 50% of PM2.5 mass at southwestern sites in spring and across the central and southeastern United States in summer (20-30% of PM2.5). The highest seasonal variability in FD occurred at sites in the Southeast during summer, likely associated with impacts from North African transport, which was also evidenced in the elemental ratios of calcium, iron, and aluminum. Long-term trend analyses (2000-2015) indicated widespread, regional increases in FD concentrations during spring in the West, especially in March in the Southwest. This increase was associated with an early onset of the spring dust season and correlated with the Pacific Decadal Oscillation and the El Niño Southern Oscillation. The Southeast and central United States also experienced increased FD concentrations during summer and fall, respectively. Contributions of FD to PM2.5 mass have increased in regions across the United States during all seasons, in part due to increased FD concentrations but also as a result of reductions in secondary aerosols (e.g., sulfates, nitrates, and organic carbon). Increased levels of FD have important implications for its environmental and climate impacts; mitigating these impacts will require identifying and characterizing source regions and underlying mechanisms for dust episodes.

Microcomputer Unit: Generating Random Numbers.

Science.gov (United States)

Haigh, William E.

1986-01-01

Presents an activity, suitable for students in grades 6-12, on generating random numbers. Objectives, equipment needed, list of prerequisite experiences, instructional strategies, and ready-to-copy student worksheets are included. (JN)

Variability of sub-micrometer particle number size distributions and concentrations in the Western Mediterranean regional background

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Michael Cusack

2013-02-01

Full Text Available This study focuses on the daily and seasonal variability of particle number size distributions and concentrations, performed at the Montseny (MSY regional background station in the western Mediterranean from October 2010 to June 2011. Particle number concentrations at MSY were shown to be within range of various other sites across Europe reported in literature, but the seasonality of the particle number size distributions revealed significant differences. The Aitken mode is the dominant particle mode at MSY, with arithmetic mean concentrations of 1698 cm3, followed by the accumulation mode (877 cm−3 and the nucleation mode (246 cm−3. Concentrations showed a strong seasonal variability with large increases in particle number concentrations observed from the colder to warmer months. The modality of median size distributions was typically bimodal, except under polluted conditions when the size distribution was unimodal. During the colder months, the daily variation of particle number size distributions are strongly influenced by a diurnal breeze system, whereby the Aitken and accumulation modes vary similarly to PM1 and BC mass concentrations, with nocturnal minima and sharp day-time increases owing to the development of a diurnal mountain breeze. Under clean air conditions, high levels of nucleation and lower Aitken mode concentrations were measured, highlighting the importance of new particle formation as a source of particles in the absence of a significant condensation sink. During the warmer months, nucleation mode concentrations were observed to be relatively elevated both under polluted and clean conditions due to increased photochemical reactions, with enhanced subsequent growth owing to elevated concentrations of condensable organic vapours produced from biogenic volatile organic compounds, indicating that nucleation at MSY does not exclusively occur under clean air conditions. Finally, mixing of air masses between polluted and non

Prompt neutrinos from atmospheric charm in the general-mass variable-flavor-number scheme

International Nuclear Information System (INIS)

Benzke, M.; Garzelli, M.V.; Kniehl, B.A.; Kramer, G.; Moch, S.; Sigl, G.

2017-08-01

We present predictions for the prompt-neutrino flux arising from the decay of charmed mesons and baryons produced by the interactions of high-energy cosmic rays in the Earth's atmosphere, making use of a QCD approach on the basis of the general-mass variable-flavor-number scheme for the description of charm hadroproduction at NLO, complemented by a consistent set of fragmentation functions. We compare the theoretical results to those already obtained by our and other groups with different theoretical approaches. We provide comparisons with the experimental results obtained by the IceCube Collaboration in two different analyses and we discuss the implications for parton distribution functions.

S1 satellite DNA repetitive units display identical structure and overall variability in all Anatolian brown frog taxa.

Science.gov (United States)

Picariello, Orfeo; Feliciello, Isidoro; Chinali, Gianni

2016-02-01

S1 satellite DNA from Palearctic brown frogs has a species-specific structure in all European species. We characterized S1 satellite DNA from the Anatolian brown frogs Rana macrocnemis, R. camerani, and R. holtzi in order to define their taxonomic rank and the structure of this satellite in this frog lineage. Southern blots of genomic DNA digested with KpnI, EcoRV, NdeI, NheI, or StuI produced the same pattern of satellite DNA bands. Moreover, quantitative dot blots showed that this satellite DNA accounts for 0.1 % of the genome in all taxa. Analysis of the overall genomic variability of the S1a repeat sequence in specimens from various populations demonstrated that this repetitive unit also has the same size (476 bp), the same most common sequence (MCS) and the same overall variability in all three taxa, and also in R. macrocnemis tavasensis. The S1a repetitive unit presents three deletions of 9, 8 and 1 bp compared to the 494-bp S1a repeat from European frogs. The S1a MCS has three variable positions (sequence WWTK in positions 183-186), due to the presence of two repeat subpopulations with motifs AATG and WWTT in all taxa. Unlike previously analyzed mitochondrial and nuclear sequences that show considerable variations among these taxa, no difference could be detected in the structure and variability of the S1 satellite repetitive units. This suggests that these taxa should belong to a single species. Our results indicate that this satellite DNA variety probably formed when the Anatolian lineage radiated from common ancestor about 4 mya, and since then has maintained its structure in all four taxa examined.

Plant community variability on a small area in southeastern Montana

Science.gov (United States)

James G. MacCracken; Daniel W. Uresk; Richard M. Hansen

1984-01-01

Plant communities are inherently variable due to a number of environmental and biological forces. Canopy cover and aboveground biomass were determined for understory vegetation in plant communities of a prairie grassland-forest ecotone in southeastern Montana. Vegetation units were described using polar ordination and stepwise discriminant analysis. Nine of a total of...

Increased numbers of spleen colony forming units in B cell deficient CBA/N mice

International Nuclear Information System (INIS)

Wiktor-Jedrzejczak, W.; Krupienicz, A.; Scher, I.

1986-01-01

The formation of exogenous and endogenous spleen colonies was studied in immune-defective mice expressing the CBA/N X-linked xid gene. Bone marrow and spleen cells of immune deficient mice formed increased numbers of eight-day exogenous spleen colonies when transferred to either normal or B cell deficient lethally irradiated recipients. Moreover, defective mice showed increased formation of five-day endogenous spleen colonies (derived from transient endogenous colony forming units; T-CFU) and of ten-day endogenous spleen colonies (derived from CFU-S). Among the possible mechanisms responsible for the observed effects, the most probable appears the one in which decreased numbers of B cell precursors stimulate stem cell pools through a feedback mechanism. (orig.) [de

Characterization report for Area 23, Building 650 Leachfield, Corrective Action Unit Number 94, Nevada Test Site. Revision 1

International Nuclear Information System (INIS)

1998-01-01

Corrective Action Unit (CAU) Number 94, Building 650 Leachfield, is an historic laboratory disposal unit located in Area 23 at the Nevada Test Site (NTS) in Nye County, Nevada. The objectives of this project were twofold: characterize subsurface conditions at the CAU with respect to the on-site disposal unit, and provide sufficient information to develop a closure strategy for the leachfield. To this end, subsurface sampling was conducted in the vicinity of the piping above the distribution box, under and around the distribution box, and within the leachfield

Characterization report for Area 23, Building 650 Leachfield, Corrective Action Unit Number 94, Nevada Test Site. Revision 1

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-01-27

Corrective Action Unit (CAU) Number 94, Building 650 Leachfield, is an historic laboratory disposal unit located in Area 23 at the Nevada Test Site (NTS) in Nye County, Nevada. The objectives of this project were twofold: characterize subsurface conditions at the CAU with respect to the on-site disposal unit, and provide sufficient information to develop a closure strategy for the leachfield. To this end, subsurface sampling was conducted in the vicinity of the piping above the distribution box, under and around the distribution box, and within the leachfield.

Molecular epidemiology of Mycobacterium tuberculosis in aboriginal peoples of Taiwan, 2006-2011.

Science.gov (United States)

Chen, Yih-Yuan; Chang, Jia-Ru; Huang, Wei-Feng; Kuo, Shu-Chen; Yeh, Jun-Jun; Lee, Jen-Jyh; Jang, Chang-Sheng; Sun, Jun-Ren; Chiueh, Tzong-Shi; Su, Ih-Jen; Dou, Horng-Yunn

2014-04-01

Previous research revealed a 6-fold higher incidence of tuberculosis (TB) amongst aborigines compared to Han Chinese in Taiwan. To investigate the reasons for this disparity, we genotyped Mycobacterium tuberculosis (MTB) strains obtained from members of different aboriginal tribes in different geographical regions of Taiwan by using molecular methods. In total, 177 isolates of MTB collected from patients at four hospitals in Taiwan from January 2006 to December 2011 were analysed by spoligotyping, mycobacterial interspersed repetitive unit-variable number tandem-repeat (MIRU-VNTR) typing. The most prevalent strains in the eastern and central regions of Taiwan were Beijing (45.7% in eastern) and Haarlem (39.1% in eastern, 37.1% in central) lineages, whereas in southern regions the most prevalent strains were EAI (47.7%) and Haarlem (20.5%) lineages. The high prevalence of EAI in southern Taiwan aborigines may be closely associated with Austronesian culture. This study provides a first overview of the M. tuberculosis strains circulating in aboriginal populations in Taiwan. The high prevalences of certain MTB lineages within aboriginal sub-populations suggest that transmission of MTB may have been restricted to close contacts. Copyright © 2013 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

Interleukin 6 variable number of tandem repeats (VNTR) gene polymorphism in centenarians.

Science.gov (United States)

Capurso, C; Solfrizzi, V; D'Introno, A; Colacicco, A M; Capurso, S A; Semeraro, C; Capurso, A; Panza, F

2007-11-01

Recent population-based studies identified the magnitude of interleukin 6 (IL6) serum levels as a marker for functional disability, and a predictor of disability and mortality among the elderly. We investigated whether there was evidence in Southern Italy of an association between the IL6 gene variable number of tandem repeats (VNTR) polymorphism and extreme longevity, and tested for the possible interaction of apolipoprotein E (APOE) alleles with the IL6 VNTR alleles. Four alleles coding for variants of four different lengths have been identified: allele A [760 base pairs (bp)], allele B (680 bp), allele C (640 bp), and allele D (610 bp). IL6 VNTR and APOE allele and genotype frequencies were studied in a total of 61 centenarians and 94 middle-aged subjects from Southern Italy. The IL6 VNTR allele B was overrepresented in the younger control group compared with centenarians (odds ratio: 0.56, 95% confidence interval: 0.35-0.88, Bonferroni p-value VNTR alleles and APOE alleles on the odds ratios to reach extreme longevity were evaluated for the smallest number of subjects in centenarians and younger controls. Our findings suggested that the presence of the IL6 VNTR allele B could be detrimental for reaching extreme longevity.

Exploratory factor analysis for differentiating sensory and mechanical variables related to muscle-tendon unit elongation

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Mauro H. Chagas

2016-01-01

Full Text Available ABSTRACT Background Stretching exercises are able to promote adaptations in the muscle-tendon unit (MTU, which can be tested through physiological and biomechanical variables. Identifying the key variables in MTU adaptations is crucial to improvements in training. Objective To perform an exploratory factor analysis (EFA involving the variables often used to evaluate the response of the MTU to stretching exercises. Method Maximum joint range of motion (ROMMAX, ROM at first sensation of stretching (FSTROM, peak torque (torqueMAX, passive stiffness, normalized stiffness, passive energy, and normalized energy were investigated in 36 participants during passive knee extension on an isokinetic dynamometer. Stiffness and energy values were normalized by the muscle cross-sectional area and their passive mode assured by monitoring the EMG activity. Results EFA revealed two major factors that explained 89.68% of the total variance: 53.13% was explained by the variables torqueMAX, passive stiffness, normalized stiffness, passive energy, and normalized energy, whereas the remaining 36.55% was explained by the variables ROMMAX and FSTROM. Conclusion This result supports the literature wherein two main hypotheses (mechanical and sensory theories have been suggested to describe the adaptations of the MTU to stretching exercises. Contrary to some studies, in the present investigation torqueMAX was significantly correlated with the variables of the mechanical theory rather than those of the sensory theory. Therefore, a new approach was proposed to explain the behavior of the torqueMAX during stretching exercises.

Handling large numbers of observation units in three-way methods for the analysis of qualitative and quantitative two-way data

NARCIS (Netherlands)

Kiers, Henk A.L.; Marchetti, G.M.

1994-01-01

Recently, a number of methods have been proposed for the exploratory analysis of mixtures of qualitative and quantitative variables. In these methods for each variable an object by object similarity matrix is constructed, and these are consequently analyzed by means of three-way methods like

A random number generator for continuous random variables

Science.gov (United States)

Guerra, V. M.; Tapia, R. A.; Thompson, J. R.

1972-01-01

A FORTRAN 4 routine is given which may be used to generate random observations of a continuous real valued random variable. Normal distribution of F(x), X, E(akimas), and E(linear) is presented in tabular form.

Importance of Viral Sequence Length and Number of Variable and Informative Sites in Analysis of HIV Clustering.

Science.gov (United States)

Novitsky, Vlad; Moyo, Sikhulile; Lei, Quanhong; DeGruttola, Victor; Essex, M

2015-05-01

To improve the methodology of HIV cluster analysis, we addressed how analysis of HIV clustering is associated with parameters that can affect the outcome of viral clustering. The extent of HIV clustering and tree certainty was compared between 401 HIV-1C near full-length genome sequences and subgenomic regions retrieved from the LANL HIV Database. Sliding window analysis was based on 99 windows of 1,000 bp and 45 windows of 2,000 bp. Potential associations between the extent of HIV clustering and sequence length and the number of variable and informative sites were evaluated. The near full-length genome HIV sequences showed the highest extent of HIV clustering and the highest tree certainty. At the bootstrap threshold of 0.80 in maximum likelihood (ML) analysis, 58.9% of near full-length HIV-1C sequences but only 15.5% of partial pol sequences (ViroSeq) were found in clusters. Among HIV-1 structural genes, pol showed the highest extent of clustering (38.9% at a bootstrap threshold of 0.80), although it was significantly lower than in the near full-length genome sequences. The extent of HIV clustering was significantly higher for sliding windows of 2,000 bp than 1,000 bp. We found a strong association between the sequence length and proportion of HIV sequences in clusters, and a moderate association between the number of variable and informative sites and the proportion of HIV sequences in clusters. In HIV cluster analysis, the extent of detectable HIV clustering is directly associated with the length of viral sequences used, as well as the number of variable and informative sites. Near full-length genome sequences could provide the most informative HIV cluster analysis. Selected subgenomic regions with a high extent of HIV clustering and high tree certainty could also be considered as a second choice.

Development and validation of a single-tube multiple-locus variable number tandem repeat analysis for Klebsiella pneumoniae.

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Antoinette A T P Brink

Full Text Available Genotyping of Klebsiella pneumoniae is indispensable for management of nosocomial infections, monitoring of emerging strains--including extended-spectrum beta-lactamase (ESBL producers-, and general epidemiology. Such objectives require a high-resolution genotyping method with a fixed scheme that allows (1 long-term retrospective and prospective assessment, (2 objective result readout and (3 library storage for database development and exchangeable results. We have developed a multiple-locus variable number tandem repeat analysis (MLVA using a single-tube fluorescently primed multiplex PCR for 8 Variable Number Tandem Repeats (VNTRs and automated fragment size analysis. The type allocation scheme was optimized using 224 K. pneumoniae clinical isolates, which yielded 101 MLVA types. The method was compared to the gold standard multilocus sequence typing (MLST using a subset of these clinical isolates (n = 95 and found to be highly concordant, with at least as high a resolution but with considerably less hands-on time. Our results position this MLVA scheme as an appropriate, high-throughput and relatively low-cost tool for K. pneumoniae epidemiology.

Energy saving opportunity with variable speed drive in primary air-handling unit

International Nuclear Information System (INIS)

Li, J.S.M.

2007-01-01

Air conditioners used in the court buildings in Kowloon City, Hong Kong were retrofitted with variable speed drives in the primary air handling unit (PAU) in an effort to reduce energy consumption. The initial effect of this retrofit was investigated along with the feasibility of using a carbon dioxide (CO 2 ) based demand control ventilation to reduce energy consumption while optimizing indoor air quality. The air flow in most air conditioning fans is either constant or controlled by motorized inlet guide vanes. Although this controls the flow and may reduce the load on the fan, this constriction adds an energy loss, resulting in inefficient operation. Variable speed drives should be used on the PAU in order to maintain system efficiency. As the speed of the fans are reduced, the flow will decrease proportionally, while the power required by the fan will reduce the cube of the speed. Therefore, if the fresh air supply can be controlled by reducing the speed of the fan motor, then flow control would be more efficient. The energy saving associated with variable fresh air supply flow rate was evaluated along with the cost to building owners. This paper presented the results of the potential energy and cost savings associated with this retrofit, and included implementation cost and pay back period. It was estimated that about 20 per cent of power consumption and electricity costs can be saved per year, with a simple payback period of 2 years. 7 refs., 3 tabs., 3 figs

Glycaemic variability in patients with severe sepsis or septic shock admitted to an Intensive Care Unit.

Science.gov (United States)

Silveira, L M; Basile-Filho, A; Nicolini, E A; Dessotte, C A M; Aguiar, G C S; Stabile, A M

2017-08-01

Sepsis is associated with morbidity and mortality, which implies high costs to the global health system. Metabolic alterations that increase glycaemia and glycaemic variability occur during sepsis. To verify mean body glucose levels and glycaemic variability in Intensive Care Unit (ICU) patients with severe sepsis or septic shock. Retrospective and exploratory study that involved collection of patients' sociodemographic and clinical data and calculation of severity scores. Glycaemia measurements helped to determine glycaemic variability through standard deviation and mean amplitude of glycaemic excursions. Analysis of 116 medical charts and 6730 glycaemia measurements revealed that the majority of patients were male and aged over 60 years. Surgical treatment was the main reason for ICU admission. High blood pressure and diabetes mellitus were the most usual comorbidities. Patients that died during the ICU stay presented the highest SOFA scores and mean glycaemia; they also experienced more hypoglycaemia events. Patients with diabetes had higher mean glycaemia, evaluated through standard deviation and mean amplitude of glycaemia excursions. Organic impairment at ICU admission may underlie glycaemic variability and lead to a less favourable outcome. High glycaemic variability in patients with diabetes indicates that monitoring of these individuals is crucial to ensure better outcomes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Multiple-locus variable-number tandem-repeat analysis of pathogenic Yersinia enterocolitica in China.

Directory of Open Access Journals (Sweden)

Xin Wang

Full Text Available The predominant bioserotypes of pathogenic Yersinia enterocolitica in China are 2/O: 9 and 3/O: 3; no pathogenic O: 8 strains have been found to date. Multiple-Locus Variable-Number Tandem-Repeat Analysis (MLVA based on seven loci was able to distinguish 104 genotypes among 218 pathogenic Y. enterocolitica isolates in China and from abroad, showing a high resolution. The major pathogenic serogroups in China, O: 3 and O: 9, were divided into two clusters based on MLVA genotyping. The different distribution of Y. enterocolitica MLVA genotypes maybe due to the recent dissemination of specific clones of 2/O: 9 and 3/O: 3 strains in China. MLVA was a helpful tool for bacterial pathogen surveillance and investigation of pathogenic Y. enterocolitica outbreaks.

Changes in Variable Number of Tandem Repeats in 'Candidatus Liberibacter asiaticus' through Insect Transmission.

Directory of Open Access Journals (Sweden)

Hiroshi Katoh

Full Text Available Citrus greening (huanglongbing is the most destructive citrus disease worldwide. The disease is associated with three species of 'Candidatus Liberibacter' among which 'Ca. Liberibacter asiaticus' has the widest distribution. 'Ca. L. asiaticus' is commonly transmitted by a phloem-feeding insect vector, the Asian citrus psyllid Diaphorina citri. A previous study showed that isolates of 'Ca. L. asiaticus' were clearly differentiated by variable number of tandem repeat (VNTR profiles at four loci in the genome. In this study, the VNTR analysis was further validated by assessing the stability of these repeats after multiplication of the pathogen upon host-to-host transmission using a 'Ca. L. asiaticus' strain from Japan. The results showed that some tandem repeats showed detectable changes after insect transmission. To our knowledge, this is the first report to demonstrate that the repeat numbers VNTR 002 and 077 of 'Ca. L. asiaticus' change through psyllid transmission. VNTRs in the recipient plant were apparently unrelated to the growing phase of the vector. In contrast, changes in the number of tandem repeats increased with longer acquisition and inoculation access periods, whereas changes were not observed through psyllid transmission after relatively short acquisition and inoculation access periods, up to 20 and 19 days, respectively.

Treating floodplain lakes of large rivers as study units for variables that vary within lakes; an evaluation using chlorophyll a and inorganic suspended solids data from floodplain lakes of the Upper Mississippi River

Science.gov (United States)

Gray, B.R.; Rogala, J.R.; Houser, J.N.

2013-01-01

Contiguous floodplain lakes ('lakes') have historically been used as study units for comparative studies of limnological variables that vary within lakes. The hierarchical nature of these studies implies that study variables may be correlated within lakes and that covariate associations may differ not only among lakes but also by spatial scale. We evaluated the utility of treating lakes as study units for limnological variables that vary within lakes based on the criteria of important levels of among-lake variation in study variables and the observation of covariate associations that vary among lakes. These concerns were selected, respectively, to ensure that lake signatures were distinguishable from within-lake variation and that lake-scale effects on covariate associations might provide inferences not available by ignoring those effects. Study data represented chlorophyll a (CHL) and inorganic suspended solids (ISS) data from lakes within three reaches of the Upper Mississippi River. Sampling occurred in summer from 1993 through 2005 (except 2003); numbers of lakes per reach varied from 7 to 19, and median lake area varied from 53 to 101 ha. CHL and ISS levels were modelled linearly, with lake, year and lake x year effects treated as random. For all reaches, the proportions of variation in CHL and ISS attributable to differences among lakes (including lake and lake x year effects) were substantial (range: 18%-73%). Finally, among-lake variation in CHL and ISS was strongly associated with covariates and covariate effects that varied by lakes or lake-years (including with vegetation levels and, for CHL, log(ISS)). These findings demonstrate the utility of treating floodplain lakes as study units for the study of limnological variables and the importance of addressing hierarchy within study designs when making inferences from data collected within floodplain lakes.

Analysis of efficiency of own and franchised units in the Spanish franchise system

OpenAIRE

Leyre Díez Uli; Félix Velicia Martín; Francisco Javier Rondán Cataluña

2017-01-01

In this work, we try to answer a key question: what are the more efficient units in franchising: owned or franchised? The literature on this specific field is very limited. To compare the efficiency of owned and franchised units we use the following variables: average sales per unit, average sales per employee and the average number of employees per unit for owned and franchised establishments. The analyses are carried out using the population of franchise chains, a database with the 1232 fra...

Estimating the number of latent cracks in pressure tube joints at Bruce unit 2

International Nuclear Information System (INIS)

Schwarz, C.J.

1983-10-01

A model was built to estimate the number of hydride cracks which might have arisen in the rolled joints of Bruce unit 2 prior to the stress relieving operation. The model estimated that about 100 such cracks might exist. Since this estimate is based on experiments that were thermally cycled and since cycling did not occur in Bruce, prior to stress relieving the actual number is expected to be substantially lower. A sensitivity analysis of the model showed that it is sensitive to the assumptions of stress levels, probability of initiation and distribution of initiation time. A better estimate could be made if more data were available on these parameters under realistic conditions. Therefore, the recommendation is made to collect more information about these factors under realistic conditions

Accuracy, calibration and clinical performance of the EuroSCORE: can we reduce the number of variables?

Science.gov (United States)

Ranucci, Marco; Castelvecchio, Serenella; Menicanti, Lorenzo; Frigiola, Alessandro; Pelissero, Gabriele

2010-03-01

The European system for cardiac operative risk evaluation (EuroSCORE) is currently used in many institutions and is considered a reference tool in many countries. We hypothesised that too many variables were included in the EuroSCORE using limited patient series. We tested different models using a limited number of variables. A total of 11150 adult patients undergoing cardiac operations at our institution (2001-2007) were retrospectively analysed. The 17 risk factors composing the EuroSCORE were separately analysed and ranked for accuracy of prediction of hospital mortality. Seventeen models were created by progressively including one factor at a time. The models were compared for accuracy with a receiver operating characteristics (ROC) analysis and area under the curve (AUC) evaluation. Calibration was tested with Hosmer-Lemeshow statistics. Clinical performance was assessed by comparing the predicted with the observed mortality rates. The best accuracy (AUC 0.76) was obtained using a model including only age, left ventricular ejection fraction, serum creatinine, emergency operation and non-isolated coronary operation. The EuroSCORE AUC (0.75) was not significantly different. Calibration and clinical performance were better in the five-factor model than in the EuroSCORE. Only in high-risk patients were 12 factors needed to achieve a good performance. Including many factors in multivariable logistic models increases the risk for overfitting, multicollinearity and human error. A five-factor model offers the same level of accuracy but demonstrated better calibration and clinical performance. Models with a limited number of factors may work better than complex models when applied to a limited number of patients. Copyright (c) 2009 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.

Variability of United States Online Rehabilitation Protocols for Proximal Hamstring Tendon Repair.

Science.gov (United States)

Lightsey, Harry M; Kantrowitz, David E; Swindell, Hasani W; Trofa, David P; Ahmad, Christopher S; Lynch, T Sean

2018-02-01

The optimal postoperative rehabilitation protocol following repair of complete proximal hamstring tendon ruptures is the subject of ongoing investigation, with a need for more standardized regimens and evidence-based modalities. To assess the variability across proximal hamstring tendon repair rehabilitation protocols published online by United States (US) orthopaedic teaching programs. Cross-sectional study. Online proximal hamstring physical therapy protocols from US academic orthopaedic programs were reviewed. A web-based search using the search term complete proximal hamstring repair rehabilitation protocol provided an additional 14 protocols. A comprehensive scoring rubric was developed after review of all protocols and was used to assess each protocol for both the presence of various rehabilitation components and the point at which those components were introduced. Of 50 rehabilitation protocols identified, 35 satisfied inclusion criteria and were analyzed. Twenty-five protocols (71%) recommended immediate postoperative bracing: 12 (34%) prescribed knee bracing, 8 (23%) prescribed hip bracing, and 5 (14%) did not specify the type of brace recommended. Fourteen protocols (40%) advised immediate nonweightbearing with crutches, while 16 protocols (46%) permitted immediate toe-touch weightbearing. Advancement to full weightbearing was allowed at a mean of 7.1 weeks (range, 4-12 weeks). Most protocols (80%) recommended gentle knee and hip passive range of motion and active range of motion, starting at a mean 1.4 weeks (range, 0-3 weeks) and 4.0 weeks (range, 0-6 weeks), respectively. However, only 6 protocols (17%) provided specific time points to initiate full hip and knee range of motion: a mean 8.0 weeks (range, 4-12 weeks) and 7.8 weeks (range, 0-12 weeks), respectively. Considerable variability was noted in the inclusion and timing of strengthening, stretching, proprioception, and cardiovascular exercises. Fifteen protocols (43%) required completion of

Recent changes in county-level corn yield variability in the United States from observations and crop models

Energy Technology Data Exchange (ETDEWEB)

Leng, Guoyong

2017-12-01

The United States is responsible for 35% and 60% of global corn supply and exports. Enhanced supply stability through a reduction in the year-to-year variability of US corn yield would greatly benefit global food security. Important in this regard is to understand how corn yield variability has evolved geographically in the history and how it relates to climatic and non-climatic factors. Results showed that year-to-year variation of US corn yield has decreased significantly during 1980-2010, mainly in Midwest Corn Belt, Nebraska and western arid regions. Despite the country-scale decreasing variability, corn yield variability exhibited an increasing trend in South Dakota, Texas and Southeast growing regions, indicating the importance of considering spatial scales in estimating yield variability. The observed pattern is partly reproduced by process-based crop models, simulating larger areas experiencing increasing variability and underestimating the magnitude of decreasing variability. And 3 out of 11 models even produced a differing sign of change from observations. Hence, statistical model which produces closer agreement with observations is used to explore the contribution of climatic and non-climatic factors to the changes in yield variability. It is found that climate variability dominate the change trends of corn yield variability in the Midwest Corn Belt, while the ability of climate variability in controlling yield variability is low in southeastern and western arid regions. Irrigation has largely reduced the corn yield variability in regions (e.g. Nebraska) where separate estimates of irrigated and rain-fed corn yield exist, demonstrating the importance of non-climatic factors in governing the changes in corn yield variability. The results highlight the distinct spatial patterns of corn yield variability change as well as its influencing factors at the county scale. I also caution the use of process-based crop models, which have substantially underestimated

A simulation study of sample size demonstrated the importance of the number of events per variable to develop prediction models in clustered data

NARCIS (Netherlands)

Wynants, L.; Bouwmeester, W.; Moons, K. G. M.; Moerbeek, M.; Timmerman, D.; Van Huffel, S.; Van Calster, B.; Vergouwe, Y.

2015-01-01

Objectives: This study aims to investigate the influence of the amount of clustering [intraclass correlation (ICC) = 0%, 5%, or 20%], the number of events per variable (EPV) or candidate predictor (EPV = 5, 10, 20, or 50), and backward variable selection on the performance of prediction models.

The effects of variability on the number-flux-density relationship for radio sources

International Nuclear Information System (INIS)

Schuch, N.J.

1981-01-01

It has been known for some time that the number-flux-density relationship for radio sources requires a population of sources whose properties evolve with cosmological epoch, at least in models where the redshifts are all taken to be cosmological. In particular, the surveys made at metre wavelengths show, for bright sources, a slope of the log N -log S curve which is steeper than the value -1.5 expected in a static, non-evolving Euclidean universe. Here, N is the number of radio sources brighter than flux density S. Expansion without evolution in conventional geometrical models predicts slopes flatter than -1.5. If the radio survey is carried out at higher frequencies (typically 2.7 or 5 GHz - 11 or 6 cm wavelength), the slope of the log N -log S curve is steeper than -1.5 but not so steep as the slopes found for the low-frequency surveys. Many of the sources found in high-frequency surveys have radio spectra with relatively higher flux-densities in the centimetre range; these sources are frequently variable at high frequencies, with time-scales from a month or two upwards. Some possible effects of the variations on the observed counts of radio sources are considered. (author)

Basketball lay-up - foot loading characteristics and the number of trials necessary to obtain stable plantar pressure variables.

Science.gov (United States)

Chua, YaoHui K; Quek, Raymond K K; Kong, Pui W

2017-03-01

This study aimed (1) to profile the plantar loading characteristics when performing the basketball lay-up in a realistic setting and (2) to determine the number of trials necessary to establish a stable mean for plantar loading variables during the lay-up. Thirteen university male basketball players [age: 23.0 (1.4) years, height: 1.75 (0.05) m, mass: 68.4 (8.6) kg] performed ten successful basketball lay-ups from a stationary position. Plantar loading variables were recorded using the Novel Pedar-X in-shoe system. Loading variables including peak force, peak pressure, and pressure-time integral were extracted from eight foot regions. Performance stability of plantar loading variables during the take-off and landing steps were assessed using the sequential averaging technique and intra-class correlation coefficient (ICC). High plantar loadings were experienced at the heel during the take-off steps, and both the heel and forefoot regions upon landing. The sequential estimation technique revealed a five-eight trial range to achieve a stable mean across all plantar loading variables, whereas ICC analysis was insensitive to inter-trial differences of repeated lay-up performances. Future studies and performance evaluation protocols on plantar loading during basketball lay-ups should include at least eight trials to ensure that the measurements obtained are sufficiently stable.

Temporal and spatial variability of frost-free seasons in the Great Lakes region of the United States

Science.gov (United States)

Lejiang Yu; Shiyuan Zhong; Xindi Bian; Warren E. Heilman; Jeffrey A. Andresen

2014-01-01

The frequency and timing of frost events and the length of the growing season are critical limiting factors in many human and natural ecosystems. This study investigates the temporal and spatial variability of the date of last spring frost (LSF), the date of first fall frost (FFF), and the length of the frost-free season (FFS) in the Great Lakes region of the United...

The influence of climate variability on numbers of three waterbird species in Western Port, Victoria, 1973 2002

Science.gov (United States)

Chambers, Lynda E.; Loyn, Richard H.

2006-05-01

Seasonal and annual movements of Australian waterbirds are generally more complex than those of their Northern Hemisphere counterparts, and long-term data are needed to understand their relationships with climatic variables. This paper explores a long-term (1973 2002) set of waterbird counts from coastal Victoria and relates them to climatic data at local and continental scales. Three species (Black Swan Cygnus atratus, White-faced Heron Egretta novaehollandiae and Grey Teal Anas gracilis) were chosen for this analysis. Black Swans have large local breeding populations near the study region; White-faced Herons have smaller local breeding populations and Grey Teal breed extensively in ephemeral inland floodplains, such as those in the Murray-Darling Basin. All showed significant relationships with streamflow, regional rainfall and the Southern Oscillation Index (SOI) at appropriate scales and time-lags, with streamflow explaining the most variance. Black Swans showed a strong seasonal cycle in abundance and local climate variables had the greatest influence on the counts. Numbers were positively correlated with streamflow in southern Victoria three to six seasons before each count. Broader-scale climatic patterns were more important for the other two species. Numbers of White-faced Herons were positively correlated with streamflow or rainfall over various parts of Australia seven to nine seasons before each count. Numbers of Grey Teal showed weak seasonal cycles, and were negatively correlated with rainfall in Victoria or the Murray-Darling Basin in the seasons before or during each count, and positively with streamflow in the Murray-Darling Basin 15 18 months before each count.

Climate and climate variability of the wind power resources in the Great Lakes region of the United States

Science.gov (United States)

X. Li; S. Zhong; X. Bian; W.E. Heilman

2010-01-01

The climate and climate variability of low-level winds over the Great Lakes region of the United States is examined using 30 year (1979-2008) wind records from the recently released North American Regional Reanalysis (NARR), a three-dimensional, high-spatial and temporal resolution, and dynamically consistent climate data set. The analyses focus on spatial distribution...

A measure of watershed nonlinearity: interpreting a variable instantaneous unit hydrograph model on two vastly different sized watersheds

Directory of Open Access Journals (Sweden)

J. Y. Ding

2011-01-01

Full Text Available The linear unit hydrograph used in hydrologic design analysis and flood forecasting is known as the transfer function and the kernel function in time series analysis and systems theory, respectively. This paper reviews the use of an input-dependent or variable kernel in a linear convolution integral as a quasi-nonlinear approach to unify nonlinear overland flow, channel routing and catchment runoff processes. The conceptual model of a variable instantaneous unit hydrograph (IUH is characterized by a nonlinear storage-discharge relation, q = c^Ns^N, where the storage exponent N is an index or degree of watershed nonlinearity, and the scale parameter c is a discharge coefficient. When the causative rainfall excess intensity of a unit hydrograph is known, parameters N and c can be determined directly from its shape factor, which is the product of the unit peak ordinate and the time to peak, an application of the statistical method of moments in its simplest form. The 2-parameter variable IUH model is calibrated by the shape factor method and verified by convolution integral using both the direct and inverse Bakhmeteff varied-flow functions on two watersheds of vastly different sizes, each having a family of four or five unit hydrographs as reported by the well-known Minshall (1960 paper and the seldom-quoted Childs (1958 one, both located in the US. For an 11-hectare catchment near Edwardsville in southern Illinois, calibration for four moderate storms shows an average N value of 1.79, which is 7% higher than the theoretical value of 1.67 by Manning friction law, while the heaviest storm, which is three to six times larger than the next two events in terms of the peak discharge and runoff volume, follows the Chezy law of 1.5. At the other end of scale, for the Naugatuck River at Thomaston in Connecticut having a drainage area of 186.2 km², the average calibrated

Climatic and physiographic controls of spatial variability in surface water balance over the contiguous United States using the Budyko relationship

Science.gov (United States)

Abatzoglou, John T.; Ficklin, Darren L.

2017-09-01

The geographic variability in the partitioning of precipitation into surface runoff (Q) and evapotranspiration (ET) is fundamental to understanding regional water availability. The Budyko equation suggests this partitioning is strictly a function of aridity, yet observed deviations from this relationship for individual watersheds impede using the framework to model surface water balance in ungauged catchments and under future climate and land use scenarios. A set of climatic, physiographic, and vegetation metrics were used to model the spatial variability in the partitioning of precipitation for 211 watersheds across the contiguous United States (CONUS) within Budyko's framework through the free parameter ω. A generalized additive model found that four widely available variables, precipitation seasonality, the ratio of soil water holding capacity to precipitation, topographic slope, and the fraction of precipitation falling as snow, explained 81.2% of the variability in ω. The ω model applied to the Budyko equation explained 97% of the spatial variability in long-term Q for an independent set of watersheds. The ω model was also applied to estimate the long-term water balance across the CONUS for both contemporary and mid-21st century conditions. The modeled partitioning of observed precipitation to Q and ET compared favorably across the CONUS with estimates from more sophisticated land-surface modeling efforts. For mid-21st century conditions, the model simulated an increase in the fraction of precipitation used by ET across the CONUS with declines in Q for much of the eastern CONUS and mountainous watersheds across the western United States.

Imported brucellosis in Denmark: Molecular identification and multiple-locus variable number tandem repeat analysis (MLVA) genotyping of the bacteria

DEFF Research Database (Denmark)

Aftab, H.; Dargis, R.; Christensen, J. J.

2011-01-01

A polymerase chain reaction was used to identify Brucella species isolated from humans in Denmark. Consecutive analysis of referred bacteria and re-examination of historical isolates identified all as Brucella melitensis. Multiple-locus variable number tandem repeat analysis (MLVA) placed...... the isolates in the previously defined 'East Mediterranean' B. melitensis group....

Intra-rater reliability of motor unit number estimation and quantitative motor unit analysis in subjects with amyotrophic lateral sclerosis.

Science.gov (United States)

Ives, Colleen T; Doherty, Timothy J

2014-01-01

To assess the intra-rater reliability of decomposition-enhanced spike-triggered averaging (DE-STA) motor unit number estimation (MUNE) and quantitative motor unit potential analysis in the upper trapezius (UT) and biceps brachii (BB) of subjects with amyotrophic lateral sclerosis (ALS) and to compare the results from the UT to control data. Patients diagnosed with clinically probable or definite ALS completed the experimental protocol twice with the same evaluator for the UT (n=10) and BB (n=9). Intra-rater reliability for the UT was good for the maximum compound muscle action potential (CMAP) (ICC=0.88), mean surface-detected motor unit potential (S-MUP) (ICC=0.87) and MUNE (ICC=0.88), and for the BB was moderate for maximum CMAP (ICC=0.61), and excellent for mean S-MUP (ICC=0.94) and MUNE (ICC=0.93). A significant difference between tests was found for UT MUNE. Comparing subjects with ALS to control subjects, UT maximum CMAP (p<0.01) and MUNE (p<0.001) values were significantly lower, and mean S-MUP values significantly greater (p<0.05) in subjects with ALS. This study has demonstrated the ability of the DE-STA MUNE technique to collect highly reliable data from two separate muscle groups and to detect the underlying pathophysiology of the disease. This was the first study to examine the reliability of this technique in subjects with ALS, and demonstrates its potential for future use as an outcome measure in ALS clinical trials and studies of ALS disease severity and natural history. Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Are Macro variables good predictors? A prediction based on the number of total medals acquired

Directory of Open Access Journals (Sweden)

Shahram Shafiee

2012-01-01

Full Text Available A large amount of effort is spent on forecasting the outcome of sporting events. Moreover, there are large quantities of data regarding the outcomes of sporting events and the factors which are assumed to contribute to those outcomes. In this paper we tried to predict the success of nations at the Asian Games through macro-economic, political, social and cultural variables. we used the information of variables include urban population, Education Expenditures, Age Structure, GDP Real Growth Rate, GDP Per Capita, Unemployment Rate, Population, Inflation Average, current account balance, life expectancy at birth and Merchandise Trade for all of the participating countries in Asian Games from 1970 to 2006 in order to build the model and then this model was tested by the information of variables in 2010. The prediction is based on the number of total medals acquired each country. In this research we used WEKA software that is a popular suite of machine learning software written in Java. The value of correlation coefficient between the predicted and original ranks is 90.42%. Neural Network Model, between 28 countries mentioned, predicts their ranks according to the maximum difference between predicted and original ranks of 19 countries (67.85% is 3, the maximum difference between predicted and original ranks of 8 countries (28.57% is between 4 to 6 and the difference between predicted and original ranks of 1 countries (3.57% is more than 6.

Quantitative assay for the number of leukemic spleen colony forming unit in radiation-induced murine myeloid leukemia

Energy Technology Data Exchange (ETDEWEB)

Nara, N [Tokyo Medical and Dental Univ. (Japan). School of Medicine; Bessho, M

1981-11-01

In mice with myelogenous leukemia, leukemic spleen colony forming units were assayed quantitatively. When 5 x 10/sup 3/ - 2 x 10/sup 4/ leukemic cells were transplanted to other mice of the same strain, a rectilinear relationship (p < 0.01) was found between the number of the cells transplanted and that of the colonies formed on the surface of the spleen. From these results, the authors considered that myelogenous leukemia in mice is an adequate model for acute myelogenous leukemia in human adults, and that the quantitative assay of the leukemic colony forming units can be used for sensitivity tests of antileukemic agents.

Estimating Composite Curve Number Using an Improved SCS-CN Method with Remotely Sensed Variables in Guangzhou, China

OpenAIRE

Fan, Fenglei; Deng, Yingbin; Hu, Xuefei; Weng, Qihao

2013-01-01

The rainfall and runoff relationship becomes an intriguing issue as urbanization continues to evolve worldwide. In this paper, we developed a simulation model based on the soil conservation service curve number (SCS-CN) method to analyze the rainfall-runoff relationship in Guangzhou, a rapid growing metropolitan area in southern China. The SCS-CN method was initially developed by the Natural Resources Conservation Service (NRCS) of the United States Department of Agriculture (USDA), and is on...

Review of Variable Generation Integration Charges

Energy Technology Data Exchange (ETDEWEB)

Porter, K.; Fink, S.; Buckley, M.; Rogers, J.; Hodge, B. M.

2013-03-01

The growth of wind and solar generation in the United States, and the expectation of continued growth of these technologies, dictates that the future power system will be operated in a somewhat different manner because of increased variability and uncertainty. A small number of balancing authorities have attempted to determine an 'integration cost' to account for these changes to their current operating practices. Some balancing authorities directly charge wind and solar generators for integration charges, whereas others add integration charges to projected costs of wind and solar in integrated resource plans or in competitive solicitations for generation. This report reviews the balancing authorities that have calculated variable generation integration charges and broadly compares and contrasts the methodologies they used to determine their specific integration charges. The report also profiles each balancing authority and how they derived wind and solar integration charges.

DNA fingerprinting of Mycobacterium leprae strains using variable number tandem repeat (VNTR) - fragment length analysis (FLA).

Science.gov (United States)

Jensen, Ronald W; Rivest, Jason; Li, Wei; Vissa, Varalakshmi

2011-07-15

The study of the transmission of leprosy is particularly difficult since the causative agent, Mycobacterium leprae, cannot be cultured in the laboratory. The only sources of the bacteria are leprosy patients, and experimentally infected armadillos and nude mice. Thus, many of the methods used in modern epidemiology are not available for the study of leprosy. Despite an extensive global drug treatment program for leprosy implemented by the WHO, leprosy remains endemic in many countries with approximately 250,000 new cases each year. The entire M. leprae genome has been mapped and many loci have been identified that have repeated segments of 2 or more base pairs (called micro- and minisatellites). Clinical strains of M. leprae may vary in the number of tandem repeated segments (short tandem repeats, STR) at many of these loci. Variable number tandem repeat (VNTR) analysis has been used to distinguish different strains of the leprosy bacilli. Some of the loci appear to be more stable than others, showing less variation in repeat numbers, while others seem to change more rapidly, sometimes in the same patient. While the variability of certain VNTRs has brought up questions regarding their suitability for strain typing, the emerging data suggest that analyzing multiple loci, which are diverse in their stability, can be used as a valuable epidemiological tool. Multiple locus VNTR analysis (MLVA) has been used to study leprosy evolution and transmission in several countries including China, Malawi, the Philippines, and Brazil. MLVA involves multiple steps. First, bacterial DNA is extracted along with host tissue DNA from clinical biopsies or slit skin smears (SSS). The desired loci are then amplified from the extracted DNA via polymerase chain reaction (PCR). Fluorescently-labeled primers for 4-5 different loci are used per reaction, with 18 loci being amplified in a total of four reactions. The PCR products may be subjected to agarose gel electrophoresis to verify the

The transition matrix element A{sub gq}(N) of the variable flavor number scheme at O(α{sub s}{sup 3})

Energy Technology Data Exchange (ETDEWEB)

Ablinger, J. [Research Institute for Symbolic Computation (RISC), Johannes Kepler University, Altenbergerstraße 69, A-4040 Linz (Austria); Blümlein, J.; De Freitas, A. [Deutsches Elektronen-Synchrotron, DESY, Platanenallee 6, D-15738 Zeuthen (Germany); Hasselhuhn, A. [Research Institute for Symbolic Computation (RISC), Johannes Kepler University, Altenbergerstraße 69, A-4040 Linz (Austria); Manteuffel, A. von [PRISMA Cluster of Excellence and Institute of Physics, J. Gutenberg University, D-55099 Mainz (Germany); Round, M. [Research Institute for Symbolic Computation (RISC), Johannes Kepler University, Altenbergerstraße 69, A-4040 Linz (Austria); Deutsches Elektronen-Synchrotron, DESY, Platanenallee 6, D-15738 Zeuthen (Germany); Schneider, C. [Research Institute for Symbolic Computation (RISC), Johannes Kepler University, Altenbergerstraße 69, A-4040 Linz (Austria); Wißbrock, F. [Research Institute for Symbolic Computation (RISC), Johannes Kepler University, Altenbergerstraße 69, A-4040 Linz (Austria); Deutsches Elektronen-Synchrotron, DESY, Platanenallee 6, D-15738 Zeuthen (Germany)

2014-05-15

We calculate the massive unpolarized operator matrix element A{sub gq}{sup (3)}(N) to 3-loop order in Quantum Chromodynamics at general values of the Mellin variable N. This is the first complete transition function needed in the variable flavor number scheme obtained at O(α{sub s}{sup 3}). A first independent recalculation is performed for the contributions ∝N{sub F} of the 3-loop anomalous dimension γ{sub gq}{sup (2)}(N)

Design and FPGA Implementation of Variable Cutoff Frequency Filter based on Continuously Variable Fractional Delay Structure and Interpolation Technique

Directory of Open Access Journals (Sweden)

Sumedh Dhabu

2015-09-01

Full Text Available This paper presents the design and FPGA implementation of interpolated continuously variable fractional delay structure based filter (ICVFD filter with fine control over the cutoff frequency. In the ICVFD filter, each unit delay of the prototype lowpass filter is replaced by a continuously variable fractional delay (CVFD element proposed in this paper. The CVFD element requires the same number of multiplications as that of the second-order fractional delay structure used in the existing fractional delay structure based variable filter (FDS based filter, however it provides fractional delays corresponding to the higher-order fractional delay structures. Hence, the proposed ICVFD filter provides wider cutoff frequency range compared to the FDS based filter. The ICVFD filter is also capable of providing variable bandpass and highpass responses. We use two-stage approach for the FPGA implementation of the ICVFD filter. First, we use pipelining stages to shorten the critical path and improve the operating frequency. Then, we make use of specific hardware resource, i.e. RAM-based Shift Register (SRL to further improve the operating frequency and resource usage.

Variability of United States Online Rehabilitation Protocols for Proximal Hamstring Tendon Repair

Science.gov (United States)

Lightsey, Harry M.; Kantrowitz, David E.; Swindell, Hasani W.; Trofa, David P.; Ahmad, Christopher S.; Lynch, T. Sean

2018-01-01

Background: The optimal postoperative rehabilitation protocol following repair of complete proximal hamstring tendon ruptures is the subject of ongoing investigation, with a need for more standardized regimens and evidence-based modalities. Purpose: To assess the variability across proximal hamstring tendon repair rehabilitation protocols published online by United States (US) orthopaedic teaching programs. Study Design: Cross-sectional study. Methods: Online proximal hamstring physical therapy protocols from US academic orthopaedic programs were reviewed. A web-based search using the search term complete proximal hamstring repair rehabilitation protocol provided an additional 14 protocols. A comprehensive scoring rubric was developed after review of all protocols and was used to assess each protocol for both the presence of various rehabilitation components and the point at which those components were introduced. Results: Of 50 rehabilitation protocols identified, 35 satisfied inclusion criteria and were analyzed. Twenty-five protocols (71%) recommended immediate postoperative bracing: 12 (34%) prescribed knee bracing, 8 (23%) prescribed hip bracing, and 5 (14%) did not specify the type of brace recommended. Fourteen protocols (40%) advised immediate nonweightbearing with crutches, while 16 protocols (46%) permitted immediate toe-touch weightbearing. Advancement to full weightbearing was allowed at a mean of 7.1 weeks (range, 4-12 weeks). Most protocols (80%) recommended gentle knee and hip passive range of motion and active range of motion, starting at a mean 1.4 weeks (range, 0-3 weeks) and 4.0 weeks (range, 0-6 weeks), respectively. However, only 6 protocols (17%) provided specific time points to initiate full hip and knee range of motion: a mean 8.0 weeks (range, 4-12 weeks) and 7.8 weeks (range, 0-12 weeks), respectively. Considerable variability was noted in the inclusion and timing of strengthening, stretching, proprioception, and cardiovascular exercises

Integer linear models with a polynomial number of variables and constraints for some classical combinatorial optimization problems

Directory of Open Access Journals (Sweden)

Nelson Maculan

2003-01-01

Full Text Available We present integer linear models with a polynomial number of variables and constraints for combinatorial optimization problems in graphs: optimum elementary cycles, optimum elementary paths and optimum tree problems.Apresentamos modelos lineares inteiros com um número polinomial de variáveis e restrições para problemas de otimização combinatória em grafos: ciclos elementares ótimos, caminhos elementares ótimos e problemas em árvores ótimas.

A comment on "bats killed in large numbers at United States wind energy facilities"

Science.gov (United States)

Huso, Manuela M.P.; Dalthorp, Dan

2014-01-01

Widespread reports of bat fatalities caused by wind turbines have raised concerns about the impacts of wind power development. Reliable estimates of the total number killed and the potential effects on populations are needed, but it is crucial that they be based on sound data. In a recent BioScience article, Hayes (2013) estimated that over 600,000 bats were killed at wind turbines in the United States in 2012. The scientific errors in the analysis are numerous, with the two most serious being that the included sites constituted a convenience sample, not a representative sample, and that the individual site estimates are derived from such different methodologies that they are inherently not comparable. This estimate is almost certainly inaccurate, but whether the actual number is much smaller, much larger, or about the same is uncertain. An accurate estimate of total bat fatality is not currently possible, given the shortcomings of the available data.

Molecular epidemiology of Mycobacterium tuberculosis in Baja California, Mexico: A result of human migration?

Science.gov (United States)

Flores-López, Carlos A; Zenteno-Cuevas, Roberto; Laniado-Laborín, Rafael; Reynaud, Yann; García-Ortiz, Rosa Alejandra; González-Y-Merchand, Jorge A; Rivera, Sandra; Vázquez-Chacón, Carlos A; Vaughan, Gilberto; Martínez-Guarneros, José Armando; Victoria-Cota, Nelva Lorena; Cruz-Rivera, Mayra; Rastogi, Nalin; Muñiz-Salazar, Raquel

2017-11-01

The State of Baja California (BC) exhibits the highest incidence and prevalence rates of tuberculosis (TB), and multidrug-resistant TB (MDR-TB) in Mexico. However information about the circulation of M. tuberculosis lineages in BC and Mexico as a whole is limited. Here, we describe the genetic relationship and genetic diversity among M. tuberculosis clinical isolates (n=140) collected in BC between October 2009 and April 2011 with other regions of Mexico, the United States, and Latin America. All specimens were genotyped based on 24 mycobacterial interspersed repetitive units (MIRU)-variable number of tandem repeats (VNTR) loci. Population structure and minimum spanning tree (MST) analyses were used to assess the genetic diversity and distribution of BC isolates in comparison to USA and South America strains. Among the nine lineages observed, LAM, Haarlem and S were the most frequent identified in BC. Population structure analysis clustered most BC isolates (41%) into three distinctive groups that included strains from San Diego and South America, whereas other BC strains (22%) clustered with other Mexican strains. A subset of isolates (12%) seemed to be autochthonous of BC, while 25% were cosmopolitan and grouped into multiple clusters. It is highly likely that the TB genetic structure observed in BC is due to human migration. Additional studies are required to determine the mechanism involved in the phylogeographic distribution of M. tuberculosis in Mexico. Implementation of domestic molecular TB surveillance programs is required to better understand the molecular epidemiology of TB not only in the region but at the national level. Copyright © 2016 Elsevier B.V. All rights reserved.

Sensitivity Analysis of Weather Variables on Offsite Consequence Analysis Tools in South Korea and the United States

Directory of Open Access Journals (Sweden)

Min-Uk Kim

2018-05-01

Full Text Available We studied sensitive weather variables for consequence analysis, in the case of chemical leaks on the user side of offsite consequence analysis (OCA tools. We used OCA tools Korea Offsite Risk Assessment (KORA and Areal Location of Hazardous Atmospheres (ALOHA in South Korea and the United States, respectively. The chemicals used for this analysis were 28% ammonia (NH3, 35% hydrogen chloride (HCl, 50% hydrofluoric acid (HF, and 69% nitric acid (HNO3. The accident scenarios were based on leakage accidents in storage tanks. The weather variables were air temperature, wind speed, humidity, and atmospheric stability. Sensitivity analysis was performed using the Statistical Package for the Social Sciences (SPSS program for dummy regression analysis. Sensitivity analysis showed that impact distance was not sensitive to humidity. Impact distance was most sensitive to atmospheric stability, and was also more sensitive to air temperature than wind speed, according to both the KORA and ALOHA tools. Moreover, the weather variables were more sensitive in rural conditions than in urban conditions, with the ALOHA tool being more influenced by weather variables than the KORA tool. Therefore, if using the ALOHA tool instead of the KORA tool in rural conditions, users should be careful not to cause any differences in impact distance due to input errors of weather variables, with the most sensitive one being atmospheric stability.

Sensitivity Analysis of Weather Variables on Offsite Consequence Analysis Tools in South Korea and the United States.

Science.gov (United States)

Kim, Min-Uk; Moon, Kyong Whan; Sohn, Jong-Ryeul; Byeon, Sang-Hoon

2018-05-18

We studied sensitive weather variables for consequence analysis, in the case of chemical leaks on the user side of offsite consequence analysis (OCA) tools. We used OCA tools Korea Offsite Risk Assessment (KORA) and Areal Location of Hazardous Atmospheres (ALOHA) in South Korea and the United States, respectively. The chemicals used for this analysis were 28% ammonia (NH₃), 35% hydrogen chloride (HCl), 50% hydrofluoric acid (HF), and 69% nitric acid (HNO₃). The accident scenarios were based on leakage accidents in storage tanks. The weather variables were air temperature, wind speed, humidity, and atmospheric stability. Sensitivity analysis was performed using the Statistical Package for the Social Sciences (SPSS) program for dummy regression analysis. Sensitivity analysis showed that impact distance was not sensitive to humidity. Impact distance was most sensitive to atmospheric stability, and was also more sensitive to air temperature than wind speed, according to both the KORA and ALOHA tools. Moreover, the weather variables were more sensitive in rural conditions than in urban conditions, with the ALOHA tool being more influenced by weather variables than the KORA tool. Therefore, if using the ALOHA tool instead of the KORA tool in rural conditions, users should be careful not to cause any differences in impact distance due to input errors of weather variables, with the most sensitive one being atmospheric stability.

Systematic, cross-cortex variation in neuron numbers in rodents and primates.

Science.gov (United States)

Charvet, Christine J; Cahalane, Diarmuid J; Finlay, Barbara L

2015-01-01

Uniformity, local variability, and systematic variation in neuron numbers per unit of cortical surface area across species and cortical areas have been claimed to characterize the isocortex. Resolving these claims has been difficult, because species, techniques, and cortical areas vary across studies. We present a stereological assessment of neuron numbers in layers II-IV and V-VI per unit of cortical surface area across the isocortex in rodents (hamster, Mesocricetus auratus; agouti, Dasyprocta azarae; paca, Cuniculus paca) and primates (owl monkey, Aotus trivigratus; tamarin, Saguinus midas; capuchin, Cebus apella); these chosen to vary systematically in cortical size. The contributions of species, cortical areas, and techniques (stereology, "isotropic fractionator") to neuron estimates were assessed. Neurons per unit of cortical surface area increase across the rostro-caudal (RC) axis in primates (varying by a factor of 1.64-2.13 across the rostral and caudal poles) but less in rodents (varying by a factor of 1.15-1.54). Layer II-IV neurons account for most of this variation. When integrated into the context of species variation, and this RC gradient in neuron numbers, conflicts between studies can be accounted for. The RC variation in isocortical neurons in adulthood mirrors the gradients in neurogenesis duration in development. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

SpolSimilaritySearch - A web tool to compare and search similarities between spoligotypes of Mycobacterium tuberculosis complex.

Science.gov (United States)

Couvin, David; Zozio, Thierry; Rastogi, Nalin

2017-07-01

Spoligotyping is one of the most commonly used polymerase chain reaction (PCR)-based methods for identification and study of genetic diversity of Mycobacterium tuberculosis complex (MTBC). Despite its known limitations if used alone, the methodology is particularly useful when used in combination with other methods such as mycobacterial interspersed repetitive units - variable number of tandem DNA repeats (MIRU-VNTRs). At a worldwide scale, spoligotyping has allowed identification of information on 103,856 MTBC isolates (corresponding to 98049 clustered strains plus 5807 unique isolates from 169 countries of patient origin) contained within the SITVIT2 proprietary database of the Institut Pasteur de la Guadeloupe. The SpolSimilaritySearch web-tool described herein (available at: http://www.pasteur-guadeloupe.fr:8081/SpolSimilaritySearch) incorporates a similarity search algorithm allowing users to get a complete overview of similar spoligotype patterns (with information on presence or absence of 43 spacers) in the aforementioned worldwide database. This tool allows one to analyze spread and evolutionary patterns of MTBC by comparing similar spoligotype patterns, to distinguish between widespread, specific and/or confined patterns, as well as to pinpoint patterns with large deleted blocks, which play an intriguing role in the genetic epidemiology of M. tuberculosis. Finally, the SpolSimilaritySearch tool also provides with the country distribution patterns for each queried spoligotype. Copyright © 2017 Elsevier Ltd. All rights reserved.

Variable Copy Number, Intra-Genomic Heterogeneities and Lateral Transfers of the 16S rRNA Gene in Pseudomonas

Science.gov (United States)

Bodilis, Josselin; Nsigue-Meilo, Sandrine; Besaury, Ludovic; Quillet, Laurent

2012-01-01

Even though the 16S rRNA gene is the most commonly used taxonomic marker in microbial ecology, its poor resolution is still not fully understood at the intra-genus level. In this work, the number of rRNA gene operons, intra-genomic heterogeneities and lateral transfers were investigated at a fine-scale resolution, throughout the Pseudomonas genus. In addition to nineteen sequenced Pseudomonas strains, we determined the 16S rRNA copy number in four other Pseudomonas strains by Southern hybridization and Pulsed-Field Gel Electrophoresis, and studied the intra-genomic heterogeneities by Denaturing Gradient Gel Electrophoresis and sequencing. Although the variable copy number (from four to seven) seems to be correlated with the evolutionary distance, some close strains in the P. fluorescens lineage showed a different number of 16S rRNA genes, whereas all the strains in the P. aeruginosa lineage displayed the same number of genes (four copies). Further study of the intra-genomic heterogeneities revealed that most of the Pseudomonas strains (15 out of 19 strains) had at least two different 16S rRNA alleles. A great difference (5 or 19 nucleotides, essentially grouped near the V1 hypervariable region) was observed only in two sequenced strains. In one of our strains studied (MFY30 strain), we found a difference of 12 nucleotides (grouped in the V3 hypervariable region) between copies of the 16S rRNA gene. Finally, occurrence of partial lateral transfers of the 16S rRNA gene was further investigated in 1803 full-length sequences of Pseudomonas available in the databases. Remarkably, we found that the two most variable regions (the V1 and V3 hypervariable regions) had probably been laterally transferred from another evolutionary distant Pseudomonas strain for at least 48.3 and 41.6% of the 16S rRNA sequences, respectively. In conclusion, we strongly recommend removing these regions of the 16S rRNA gene during the intra-genus diversity studies. PMID:22545126

Variability of pesticide residues in cauliflower units collected from a field trial and market places in Greece.

Science.gov (United States)

Prodhan, M D H; Papadakis, Emmanouil-N; Papadopoulou-Mourkidou, Euphemia

2016-09-01

To estimate the variability of pesticide residue levels present in cauliflower units, a total of 142 samples were collected from a field trial of a cooperative farmer, and 120 samples were collected from different market places in Thessaloniki, Greece. The collected samples were extracted using the quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction technique, and the residues were determined by liquid chromatography-tandem mass spectrometry. The developed method was validated by evaluating the accuracy, precision, linearity, limit of detection (LOD), and limit of quantification (LOQ). The average recoveries for all the analytes, derived from the data of control samples fortified at 0.01, 0.05, 0.1, and 0.2 mg/kg, ranged from 74 to 110% with a relative standard deviation of ≤8%. The correlation coefficient (R(2)) was ≥0.997 for all the analytes using matrix-matched calibration standards. The LOD values ranged from 0.001 to 0.003 mg/kg, and the LOQ was determined at 0.01 mg/kg for all the sought analytes. The matrix effect was found to be at a considerable level, especially for cypermethrin and deltamethrin, amounting to +90% and +145%, respectively. For the field samples, the unit-to-unit variability factors (VFs) calculated for cypermethrin and deltamethrin were 2.38 and 2.32, respectively, while the average VF for the market basket samples was 5.11. In the market basket samples, residues of cypermethrin, deltamethrin, chlorpyrifos, and indoxacarb were found at levels ≥LOQ and their respective VFs were 7.12, 5.67, 5.28, and 2.40.

Analysis of efficiency of own and franchised units in the Spanish franchise system

Directory of Open Access Journals (Sweden)

Leyre Díez Uli

2017-09-01

Full Text Available In this work, we try to answer a key question: what are the more efficient units in franchising: owned or franchised? The literature on this specific field is very limited. To compare the efficiency of owned and franchised units we use the following variables: average sales per unit, average sales per employee and the average number of employees per unit for owned and franchised establishments. The analyses are carried out using the population of franchise chains, a database with the 1232 franchise chains existing in Spain at the end of 2015 has been created for this purpose. The results show the higher efficiency of owned regarding franchised units.

Spatiotemporal Variability of Humidity Across the Contiguous United States and Southern Canada Using Regional Networks

Science.gov (United States)

Behnke, Ruben John

The objective of this dissertation was to show that there is now enough observed humidity data available so that estimates of humidity, along with their necessary assumptions, can be replaced by measured humidity data. The range of applications that depend on humidity data is huge, ranging from water use efficiency of plants and plant stress to human health and agricultural practices. Biases due to the use of estimated humidity can be expected to have short and long impacts, decreasing the accuracy and precision of these, and many other, applications. Data from local, regional, and national observation networks was gathered, and custom quality control routines were written to remove bad data points from over 45000 stations, leaving 12533 usable stations. While still not at the same number of observations as temperature or precipitation, this number is nearly ten times as high as two decades ago. The work I performed consists of three major components, corresponding to the three main chapters of this dissertation. In chapter one, I describe data sources and quality control methods, along with some basic statistics of humidity, describing which geographic variables often used to predict temperature and precipitation can be used to do the same for humidity. Chapter two defines specific diurnal patterns (or "types") of dew point across the United States, including their attributes, causes, and potential influences. Chapter three analyzes biases in evapotranspiration, heat indices, and relative humidity levels that are a direct result of using estimated humidity data. Chapter four discusses contributions this work makes to the scientific community, and potential further research to build on what is presented here. While it may seem that the science of humidity should be well beyond data gathering and bias analysis, the fact remains that humidity is still very commonly estimated through the use of minimum temperature, and diurnal changes in dew point are often ignored

Variable Selection for Regression Models of Percentile Flows

Science.gov (United States)

Fouad, G.

2017-12-01

Percentile flows describe the flow magnitude equaled or exceeded for a given percent of time, and are widely used in water resource management. However, these statistics are normally unavailable since most basins are ungauged. Percentile flows of ungauged basins are often predicted using regression models based on readily observable basin characteristics, such as mean elevation. The number of these independent variables is too large to evaluate all possible models. A subset of models is typically evaluated using automatic procedures, like stepwise regression. This ignores a large variety of methods from the field of feature (variable) selection and physical understanding of percentile flows. A study of 918 basins in the United States was conducted to compare an automatic regression procedure to the following variable selection methods: (1) principal component analysis, (2) correlation analysis, (3) random forests, (4) genetic programming, (5) Bayesian networks, and (6) physical understanding. The automatic regression procedure only performed better than principal component analysis. Poor performance of the regression procedure was due to a commonly used filter for multicollinearity, which rejected the strongest models because they had cross-correlated independent variables. Multicollinearity did not decrease model performance in validation because of a representative set of calibration basins. Variable selection methods based strictly on predictive power (numbers 2-5 from above) performed similarly, likely indicating a limit to the predictive power of the variables. Similar performance was also reached using variables selected based on physical understanding, a finding that substantiates recent calls to emphasize physical understanding in modeling for predictions in ungauged basins. The strongest variables highlighted the importance of geology and land cover, whereas widely used topographic variables were the weakest predictors. Variables suffered from a high

A multi locus variable number of tandem repeat analysis (MLVA scheme for Streptococcus agalactiae genotyping

Directory of Open Access Journals (Sweden)

Mereghetti Laurent

2011-07-01

Full Text Available Abstract Background Multilocus sequence typing (MLST is currently the reference method for genotyping Streptococcus agalactiae strains, the leading cause of infectious disease in newborns and a major cause of disease in immunocompromised children and adults. We describe here a genotyping method based on multiple locus variable number of tandem repeat (VNTR analysis (MLVA applied to a population of S. agalactiae strains of various origins characterized by MLST and serotyping. Results We studied a collection of 186 strains isolated from humans and cattle and three reference strains (A909, NEM316 and 2603 V/R. Among 34 VNTRs, 6 polymorphic VNTRs loci were selected for use in genotyping of the bacterial population. The MLVA profile consists of a series of allele numbers, corresponding to the number of repeats at each VNTR locus. 98 MLVA genotypes were obtained compared to 51 sequences types generated by MLST. The MLVA scheme generated clusters which corresponded well to the main clonal complexes obtained by MLST. However it provided a higher discriminatory power. The diversity index obtained with MLVA was 0.960 compared to 0.881 with MLST for this population of strains. Conclusions The MLVA scheme proposed here is a rapid, cheap and easy genotyping method generating results suitable for exchange and comparison between different laboratories and for the epidemiologic surveillance of S. agalactiae and analyses of outbreaks.

Weather data for simplified energy calculation methods. Volume II. Middle United States: TRY data

Energy Technology Data Exchange (ETDEWEB)

Olsen, A.R.; Moreno, S.; Deringer, J.; Watson, C.R.

1984-08-01

The objective of this report is to provide a source of weather data for direct use with a number of simplified energy calculation methods available today. Complete weather data for a number of cities in the United States are provided for use in the following methods: degree hour, modified degree hour, bin, modified bin, and variable degree day. This report contains sets of weather data for 22 cities in the continental United States using Test Reference Year (TRY) source weather data. The weather data at each city has been summarized in a number of ways to provide differing levels of detail necessary for alternative simplified energy calculation methods. Weather variables summarized include dry bulb and wet bulb temperature, percent relative humidity, humidity ratio, wind speed, percent possible sunshine, percent diffuse solar radiation, total solar radiation on horizontal and vertical surfaces, and solar heat gain through standard DSA glass. Monthly and annual summaries, in some cases by time of day, are available. These summaries are produced in a series of nine computer generated tables.

Hydroxyl layer: trend of number density and intra-annual variability

Science.gov (United States)

Sonnemann, G. R.; Hartogh, P.; Berger, U.; Grygalashvyly, M.

2015-06-01

The layer of vibrationally excited hydroxyl (OH*) near the mesopause in Earth's atmosphere is widely used to derive the temperature at this height and to observe dynamical processes such as gravity waves. The concentration of OH* is controlled by the product of atomic hydrogen, with ozone creating a layer of enhanced concentration in the mesopause region. However, the basic influences on the OH* layer are atomic oxygen and temperature. The long-term monitoring of this layer provides information on a changing atmosphere. It is important to know which proportion of a trend results from anthropogenic impacts on the atmosphere and which proportion reflects natural variations. In a previous paper (Grygalashvyly et al., 2014), the trend of the height of the layer and the trend in temperature were investigated particularly in midlatitudes on the basis of our coupled dynamic and chemical transport model LIMA (Leibniz Institute Middle Atmosphere). In this paper we consider the trend for the number density between the years 1961 and 2009 and analyze the reason of the trends on a global scale. Further, we consider intra-annual variations. Temperature and wind have the strongest impacts on the trend. Surprisingly, the increase in greenhouse gases (GHGs) has no clear influence on the chemistry of OH*. The main reason for this lies in the fact that, in the production term of OH*, if atomic hydrogen increases due to increasing humidity of the middle atmosphere by methane oxidation, ozone decreases. The maximum of the OH* layer is found in the mesopause region and is very variable. The mesopause region is a very intricate domain marked by changeable dynamics and strong gradients of all chemically active minor constituents determining the OH* chemistry. The OH* concentration responds, in part, very sensitively to small changes in these parameters. The cause for this behavior is given by nonlinear reactions of the photochemical system being a nonlinear enforced chemical oscillator

Hydroxyl layer: trend of number density and intra-annual variability

Directory of Open Access Journals (Sweden)

G. R. Sonnemann

2015-06-01

Full Text Available The layer of vibrationally excited hydroxyl (OH* near the mesopause in Earth's atmosphere is widely used to derive the temperature at this height and to observe dynamical processes such as gravity waves. The concentration of OH* is controlled by the product of atomic hydrogen, with ozone creating a layer of enhanced concentration in the mesopause region. However, the basic influences on the OH* layer are atomic oxygen and temperature. The long-term monitoring of this layer provides information on a changing atmosphere. It is important to know which proportion of a trend results from anthropogenic impacts on the atmosphere and which proportion reflects natural variations. In a previous paper (Grygalashvyly et al., 2014, the trend of the height of the layer and the trend in temperature were investigated particularly in midlatitudes on the basis of our coupled dynamic and chemical transport model LIMA (Leibniz Institute Middle Atmosphere. In this paper we consider the trend for the number density between the years 1961 and 2009 and analyze the reason of the trends on a global scale. Further, we consider intra-annual variations. Temperature and wind have the strongest impacts on the trend. Surprisingly, the increase in greenhouse gases (GHGs has no clear influence on the chemistry of OH*. The main reason for this lies in the fact that, in the production term of OH*, if atomic hydrogen increases due to increasing humidity of the middle atmosphere by methane oxidation, ozone decreases. The maximum of the OH* layer is found in the mesopause region and is very variable. The mesopause region is a very intricate domain marked by changeable dynamics and strong gradients of all chemically active minor constituents determining the OH* chemistry. The OH* concentration responds, in part, very sensitively to small changes in these parameters. The cause for this behavior is given by nonlinear reactions of the photochemical system being a nonlinear enforced

Brazil and the United States: The Need for Strategic Engagement (Strategic Forum, Number 266, March 2011)

Science.gov (United States)

2011-03-01

If accurate, these astonishing numbers in themselves tell the story of Brazil’s explosive growth. 7 Embrapa is short for Empresa Brasileira de ...in the world. Geography. U.S. citizens think of Brazil as be- ing Rio de Janeiro and its beautiful beaches or as the Amazon, an endless jungle...United States www.ndu.edu/inss SF No. 266 3 and port systems lag. One study suggests that domestic transportation costs and port fees for soy, Brazil’s

Variable-flavor-number scheme in analysis of heavy-quark electro-production data

International Nuclear Information System (INIS)

Alekhin, S.; Bluemlein, J.; Klein, S.; Moch, S.

2009-08-01

We check the impact of the factorization scheme employed in the calculation of the heavy-quark deep-inelastic scattering (DIS) electro-production on the PDFs determined in the NNLO QCD analysis of the world inclusive neutral-current DIS data combined with the ones on the neutrino-nucleon DIS di-muon production and the fixed-target Drell-Yan process. The charm-quark DIS contribution is calculated in the general-mass variable-flavor-number (GMVFN) scheme: At asymptotically large values of the momentum transfer Q it is given by the zero-mass 4-flavor scheme and at the value of Q equal to the charm-quark mass it is smoothly matched with the 3-flavor scheme using the Buza-Matiounine-Smith-van Neerven prescription. The PDFs obtained in this variant of the fit are very similar to the ones obtained in the fit with a 3-flavor scheme employed. Our 5-flavor PDFs derived from the 3-flavor ones using the NNLO matching conditions are used to calculate the rates of W ± /Z and t anti t production at the Tevatron collider and the LHC at NNLO. (orig.)

Reproductive capacity of Chrysoperla externa (Hagen) (Neuroptera, Chrysopidae) in function of the number of individuals per unit of rearing

International Nuclear Information System (INIS)

Pessoa, Luis Gustavo Amorim; Freitas, Sergio de

2008-01-01

Reproductive capacity of Chrysoperla externa (Hagen) (Neuroptera, Chrysopidae) in function of the number of individuals per unit of rearing. This work was carried out to investigate the reproductive potential of Chrysoperla externa subjected to different densities per rearing unit. Adults of the F 4 offspring were kept at 25 ± 1 deg C, RH 70 ± 10% and 12 h photo phase. It was used the following densities per rearing unit (10 cm of diameter by 23 cm of height, and volume of 1650 cm 3 ): 1 male: 3 female, 2 males: 6 females, 3 males: 9 females and 4 males: 12 females. It was evaluated the pre-oviposition period, the daily and total oviposition per female and per rearing unit, the percentage of viable and infertile eggs percentage and the exploitation index per female and per rearing unit. The density 4 males: 12 females presented better exploitation when compared to the other densities thus equalizing the low values obtained for the mean and total egg laying per female. (author)

Analytic number theory an introductory course

CERN Document Server

Bateman, Paul T

2004-01-01

This valuable book focuses on a collection of powerful methods ofanalysis that yield deep number-theoretical estimates. Particularattention is given to counting functions of prime numbers andmultiplicative arithmetic functions. Both real variable ("elementary")and complex variable ("analytic") methods are employed.

Reexamining the language account of cross-national differences in base-10 number representations.

Science.gov (United States)

Vasilyeva, Marina; Laski, Elida V; Ermakova, Anna; Lai, Weng-Feng; Jeong, Yoonkyung; Hachigian, Amy

2015-01-01

East Asian students consistently outperform students from other nations in mathematics. One explanation for this advantage is a language account; East Asian languages, unlike most Western languages, provide cues about the base-10 structure of multi-digit numbers, facilitating the development of base-10 number representations. To test this view, the current study examined how kindergartners represented two-digit numbers using single unit-blocks and ten-blocks. The participants (N=272) were from four language groups (Korean, Mandarin, English, and Russian) that vary in the extent of "transparency" of the base-10 structure. In contrast to previous findings with older children, kindergartners showed no cross-language variability in the frequency of producing base-10 representations. Furthermore, they showed a pattern of within-language variability that was not consistent with the language account and was likely attributable to experiential factors. These findings suggest that language might not play as critical a role in the development of base-10 representations as suggested in earlier research. Copyright © 2014 Elsevier Inc. All rights reserved.

Modeling both of the number of pausibacillary and multibacillary leprosy patients by using bivariate poisson regression

Science.gov (United States)

Winahju, W. S.; Mukarromah, A.; Putri, S.

2015-03-01

Leprosy is a chronic infectious disease caused by bacteria of leprosy (Mycobacterium leprae). Leprosy has become an important thing in Indonesia because its morbidity is quite high. Based on WHO data in 2014, in 2012 Indonesia has the highest number of new leprosy patients after India and Brazil with a contribution of 18.994 people (8.7% of the world). This number makes Indonesia automatically placed as the country with the highest number of leprosy morbidity of ASEAN countries. The province that most contributes to the number of leprosy patients in Indonesia is East Java. There are two kind of leprosy. They consist of pausibacillary and multibacillary. The morbidity of multibacillary leprosy is higher than pausibacillary leprosy. This paper will discuss modeling both of the number of multibacillary and pausibacillary leprosy patients as responses variables. These responses are count variables, so modeling will be conducted by using bivariate poisson regression method. Unit experiment used is in East Java, and predictors involved are: environment, demography, and poverty. The model uses data in 2012, and the result indicates that all predictors influence significantly.

The effect of recording site on extracted features of motor unit action potential.

Science.gov (United States)

Artuğ, N Tuğrul; Goker, Imran; Bolat, Bülent; Osman, Onur; Kocasoy Orhan, Elif; Baslo, M Baris

2016-06-01

Motor unit action potential (MUAP), which consists of individual muscle fiber action potentials (MFAPs), represents the electrical activity of the motor unit. The values of the MUAP features are changed by denervation and reinnervation in neurogenic involvement as well as muscle fiber loss with increased diameter variability in myopathic diseases. The present study is designed to investigate how increased muscle fiber diameter variability affects MUAP parameters in simulated motor units. In order to detect this variation, simulated MUAPs were calculated both at the innervation zone where the MFAPs are more synchronized, and near the tendon, where they show increased temporal dispersion. Reinnervation in neurogenic state increases MUAP amplitude for the recordings at both the innervation zone and near the tendon. However, MUAP duration and the number of peaks significantly increased in a case of myopathy for recordings near the tendon. Furthermore, of the new features, "number of peaks×spike duration" was found as the strongest indicator of MFAP dispersion in myopathy. MUAPs were also recorded from healthy participants in order to investigate the biological counterpart of the simulation data. MUAPs which were recorded near to tendon revealed significantly prolonged duration and decreased amplitude. Although the number of peaks was increased by moving the needle near to tendon, this was not significant. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Synthesis of Tumor-avid Photosensitizer-Gd(III)DTPA conjugates: impact of the number of gadolinium units in T1/T2 relaxivity, intracellular localization, and photosensitizing efficacy.

Science.gov (United States)

Goswami, Lalit N; White, William H; Spernyak, Joseph A; Ethirajan, Manivannan; Chen, Yihui; Missert, Joseph R; Morgan, Janet; Mazurchuk, Richard; Pandey, Ravindra K

2010-05-19

To develop novel bifunctional agents for tumor imaging (MR) and photodynamic therapy (PDT), certain tumor-avid photosensitizers derived from chlorophyll-a were conjugated with variable number of Gd(III)aminobenzyl DTPA moieties. All the conjugates containing three or six gadolinium units showed significant T(1) and T(2) relaxivities. However, as a bifunctional agent, the 3-(1'-hexyloxyethyl)pyropheophorbide-a (HPPH) containing 3Gd(III) aminophenyl DTPA was most promising with possible applications in tumor-imaging and PDT. Compared to HPPH, the corresponding 3- and 6Gd(III)aminobenzyl DTPA conjugates exhibited similar electronic absorption characteristics with a slightly decreased intensity of the absorption band at 660 nm. However, compared to HPPH, the excitation of the broad "Soret" band (near 400 nm) of the corresponding 3Gd(III)aminobenzyl-DTPA analogues showed a significant decrease in the fluorescence intensity at 667 nm.

Simultaneous minimizing monitor units and number of segments without leaf end abutment for segmental intensity modulated radiation therapy delivery

International Nuclear Information System (INIS)

Li Kaile; Dai Jianrong; Ma Lijun

2004-01-01

Leaf end abutment is seldom studied when delivering segmental intensity modulated radiation therapy (IMRT) fields. We developed an efficient leaf sequencing method to eliminate leaf end abutment for segmental IMRT delivery. Our method uses simple matrix and sorting operations to obtain a solution that simultaneously minimizes total monitor units and number of segments without leaf end abutment between segments. We implemented and demonstrated our method for multiple clinical cases. We compared the results of our method with the results from exhaustive search method. We found that our solution without leaf end abutment produced equivalent results to the unconstrained solutions in terms of minimum total monitor units and minimum number of leaf segments. We conclude that the leaf end abutment fields can be avoided without affecting the efficiency of segmental IMRT delivery. The major strength of our method is its simplicity and high computing speed. This potentially provides a useful means for generating segmental IMRT fields that require high spatial resolution or complex intensity distributions

Dynamics of chromosome number and genome size variation in a cytogenetically variable sedge (Carex scoparia var. scoparia, Cyperaceae).

Science.gov (United States)

Chung, Kyong-Sook; Weber, Jaime A; Hipp, Andrew L

2011-01-01

High intraspecific cytogenetic variation in the sedge genus Carex (Cyperaceae) is hypothesized to be due to the "diffuse" or non-localized centromeres, which facilitate chromosome fission and fusion. If chromosome number changes are dominated by fission and fusion, then chromosome evolution will result primarily in changes in the potential for recombination among populations. Chromosome duplications, on the other hand, entail consequent opportunities for divergent evolution of paralogs. In this study, we evaluate whether genome size and chromosome number covary within species. We used flow cytometry to estimate genome sizes in Carex scoparia var. scoparia, sampling 99 plants (23 populations) in the Chicago region, and we used meiotic chromosome observations to document chromosome numbers and chromosome pairing relations. Chromosome numbers range from 2n = 62 to 2n = 68, and nuclear DNA 1C content from 0.342 to 0.361 pg DNA. Regressions of DNA content on chromosome number are nonsignificant for data analyzed by individual or population, and a regression model that excludes slope is favored over a model in which chromosome number predicts genome size. Chromosome rearrangements within cytogenetically variable Carex species are more likely a consequence of fission and fusion than of duplication and deletion. Moreover, neither genome size nor chromosome number is spatially autocorrelated, which suggests the potential for rapid chromosome evolution by fission and fusion at a relatively fine geographic scale (<350 km). These findings have important implications for ecological restoration and speciation within the largest angiosperm genus of the temperate zone.

Large-scale studies of the HphI insulin gene variable-number-of-tandem-repeats polymorphism in relation to Type 2 diabetes mellitus and insulin release

DEFF Research Database (Denmark)

Hansen, S K; Gjesing, A P; Rasmussen, S K

2004-01-01

The class III allele of the variable-number-of-tandem-repeats polymorphism located 5' of the insulin gene (INS-VNTR) has been associated with Type 2 diabetes and altered birthweight. It has also been suggested, although inconsistently, that the class III allele plays a role in glucose-induced ins......The class III allele of the variable-number-of-tandem-repeats polymorphism located 5' of the insulin gene (INS-VNTR) has been associated with Type 2 diabetes and altered birthweight. It has also been suggested, although inconsistently, that the class III allele plays a role in glucose...

Unit-specific calibration of Actigraph accelerometers in a mechanical setup - is it worth the effort? The effect on random output variation caused by technical inter-instrument variability in the laboratory and in the field

DEFF Research Database (Denmark)

Moeller, Niels C; Korsholm, Lars; Kristensen, Peter L

2008-01-01

BACKGROUND: Potentially, unit-specific in-vitro calibration of accelerometers could increase field data quality and study power. However, reduced inter-unit variability would only be important if random instrument variability contributes considerably to the total variation in field data. Therefor...

Recruitment and derecruitment characteristics of motor units in a hand muscle of young and old adults.

Science.gov (United States)

Jesunathadas, Mark; Marmon, Adam R; Gibb, James M; Enoka, Roger M

2010-06-01

The significant decline in motor neuron number after approximately 60 yr of age is accompanied by a remodeling of the neuromuscular system so that average motor unit force increases and the ability of old adults to produce an intended force declines. One possible explanation for the loss of movement precision is that the remodeling increases the difference in recruitment forces between successively recruited motor units in old adults and this augments force variability at motor unit recruitment. The purpose of the study was to compare the forces and discharge characteristics of motor units in a hand muscle of young and old adults at motor unit recruitment and derecruitment. The difference in recruitment force between pairs of motor units did not differ between young (n=54) and old adults (n=56; P=0.702). However, old adults had a greater proportion of contractions in which motor units discharged action potentials transiently before discharging continuously during the ramp increase in force (young: 0.32; old: 0.41; P=0.045). Force variability at motor unit recruitment was greater for old adults compared with young adults (Por=0.729). These results suggest that the difference in force between the recruitment of successive motor units does not differ between age groups, but that motor unit recruitment may be more transient and could contribute to the greater variability in force observed in old adults during graded ramp contractions.

A pairwise unit-root-test based approach to investigating convergence of household debts in South Africa and the United States

Directory of Open Access Journals (Sweden)

Ntebogang Dinah Moroke

2015-05-01

Full Text Available The purpose of this paper was to test convergence of household debts in the United States and South Africa taking a pairwise unit root tests based approaches into account. Substantial number of studies dealt with convergence of several macroeconomic variables but to my knowledge no study considered this subject with respect to household debts of the identified countries. Quarterly data on household debts consisting of 88 observations in the South Africa and United States spanning the period 1990 to 2013 was collected from the South African and St. Louis Federal Reserve Banks. Focused on the absolute value of household debts, this study proved that South Africa is far from catching-up with the United States in terms of overcoming household debts for the selected period. The findings of this study can be used by relevant authorities to help improve ways and means of dealing with household debts South Africa

The Effect of Unequal Samples, Heterogeneity of Covariance Matrices, and Number of Variables on Discriminant Analysis Classification Tables and Related Statistics.

Science.gov (United States)

Spearing, Debra; Woehlke, Paula

To assess the effect on discriminant analysis in terms of correct classification into two groups, the following parameters were systematically altered using Monte Carlo techniques: sample sizes; proportions of one group to the other; number of independent variables; and covariance matrices. The pairing of the off diagonals (or covariances) with…

Application of Variable-Number Tandem-Repeat Typing To Discriminate Ralstonia solanacearum Strains Associated with English Watercourses and Disease Outbreaks

Science.gov (United States)

Bryant, Ruth; Bew, Janice; Conyers, Christine; Stones, Robert; Alcock, Michael; Elphinstone, John

2013-01-01

Variable-number tandem-repeat (VNTR) analysis was used for high-resolution discrimination among Ralstonia solanacearum phylotype IIB sequevar 1 (PIIB-1) isolates and further evaluated for use in source tracing. Five tandem-repeat-containing loci (comprising six tandem repeats) discriminated 17 different VNTR profiles among 75 isolates from potato, geranium, bittersweet (Solanum dulcamara), tomato, and the environment. R. solanacearum isolates from crops at three unrelated outbreak sites where river water had been used for irrigation had distinct VNTR profiles that were shared with PIIB-1 isolates from infected bittersweet growing upriver of each site. The VNTR profiling results supported the implication that the source of R. solanacearum at each outbreak was contaminated river water. Analysis of 51 isolates from bittersweet growing in river water at different locations provided a means to evaluate the technique for studying the epidemiology of the pathogen in the environment. Ten different VNTR profiles were identified among bittersweet PIIB-1 isolates from the River Thames. Repeated findings of contiguous river stretches that produced isolates that shared single VNTR profiles supported the hypothesis that the pathogen had disseminated from infected bittersweet plants located upriver. VNTR profiles shared between bittersweet isolates from two widely separated Thames tributaries (River Ray and River Colne) suggested they were independently contaminated with the same clonal type. Some bittersweet isolates had VNTR profiles that were shared with potato isolates collected outside the United Kingdom. It was concluded that VNTR profiling could contribute to further understanding of R. solanacearum epidemiology and assist in control of future disease outbreaks. PMID:23892739

Up-scaling of multi-variable flood loss models from objects to land use units at the meso-scale

Science.gov (United States)

Kreibich, Heidi; Schröter, Kai; Merz, Bruno

2016-05-01

Flood risk management increasingly relies on risk analyses, including loss modelling. Most of the flood loss models usually applied in standard practice have in common that complex damaging processes are described by simple approaches like stage-damage functions. Novel multi-variable models significantly improve loss estimation on the micro-scale and may also be advantageous for large-scale applications. However, more input parameters also reveal additional uncertainty, even more in upscaling procedures for meso-scale applications, where the parameters need to be estimated on a regional area-wide basis. To gain more knowledge about challenges associated with the up-scaling of multi-variable flood loss models the following approach is applied: Single- and multi-variable micro-scale flood loss models are up-scaled and applied on the meso-scale, namely on basis of ATKIS land-use units. Application and validation is undertaken in 19 municipalities, which were affected during the 2002 flood by the River Mulde in Saxony, Germany by comparison to official loss data provided by the Saxon Relief Bank (SAB).In the meso-scale case study based model validation, most multi-variable models show smaller errors than the uni-variable stage-damage functions. The results show the suitability of the up-scaling approach, and, in accordance with micro-scale validation studies, that multi-variable models are an improvement in flood loss modelling also on the meso-scale. However, uncertainties remain high, stressing the importance of uncertainty quantification. Thus, the development of probabilistic loss models, like BT-FLEMO used in this study, which inherently provide uncertainty information are the way forward.

Summary of Notifiable Diseases, United States. Volume 45, Number 53.

Science.gov (United States)

1997-10-31

Trichinosis Tuberculosis Typhoid fever Yellow fever NOTE: Although varicella is not a nationally notifiable disease, the Council of State and...plague among humans, two of which were fatal, were re- ported in the United States (two cases in Arizona, one in Colorado, and two in New Mexico ). Both...13 cases per year) were reported in the United States. Of these cases, 80% occurred in the southwestern states of New Mexico , Arizona, and

Mass and number size distributions of emitted particulates at five important operation units in a hazardous industrial waste incineration plant.

Science.gov (United States)

Lin, Chi-Chi; Huang, Hsiao-Lin; Hsiao, Wen-Yuan

2016-01-01

Past studies indicated particulates generated by waste incineration contain various hazardous compounds. The aerosol characteristics are very important for particulate hazard control and workers' protection. This study explores the detailed characteristics of emitted particulates from each important operation unit in a rotary kiln-based hazardous industrial waste incineration plant. A dust size analyzer (Grimm 1.109) and a scanning mobility particle sizer (SMPS) were used to measure the aerosol mass concentration, mass size distribution, and number size distribution at five operation units (S1-S5) during periods of normal operation, furnace shutdown, and annual maintenance. The place with the highest measured PM10 concentration was located at the area of fly ash discharge from air pollution control equipment (S5) during the period of normal operation. Fine particles (PM2.5) constituted the majority of the emitted particles from the incineration plant. The mass size distributions (elucidated) made it clear that the size of aerosols caused by the increased particulate mass, resulting from work activities, were mostly greater than 1.5 μm. Whereas the number size distributions showed that the major diameters of particulates that caused the increase of particulate number concentrations, from work activities, were distributed in the sub micrometer range. The process of discharging fly ash from air pollution control equipment can significantly increase the emission of nanoparticles. The mass concentrations and size distributions of emitted particulates were different at each operation unit. This information is valuable for managers to take appropriate strategy to reduce the particulate emission and associated worker exposure.

IDENTIFICATION OF THOSE VARIABLES THAT HAVE A SIGNIFICANT INFLUENCE ON THE EXPECTED NUMBER OF DAYS OF STAYING IN THE CENTRE DEVELOPMENT REGION OF ROMANIA

Directory of Open Access Journals (Sweden)

Erika KULCSÁR

2010-06-01

Full Text Available I started from the assumption that there are more variables that have a significant influence on the expected number of days of staying in the Centre Development Region. To identify those variables this paper includes the analysis of variance with two variables that are not interacting, in this case the dependent variable is the question "How many days did you plan to stay in Centre Development Region?" and the independent variables are: "What is the purpose of your stay?" "What is the highest level of education?". Given that there are cases when interactions occur between variables, I also analyzed the interaction effects between the two independent variables. The paper also includes an ANOVA analysis with three variables between which interactions relationships occur. After identifying the dependency relations between the variables I found that the inclusion of the third variable, namely the "Marital status" of respondents, adds value to the model. Following the results obtained by ANOVA analysis, I identified those socio-demographic characteristics that, in my opinion, companies that operate on tourist market in the Center Development Region should consider when fundamenting marketing strategies in tourism.

Molecular Typing of Mycobacterium bovis from Cattle Reared in Midwest Brazil.

Directory of Open Access Journals (Sweden)

Ricardo César Tavares Carvalho

Full Text Available Mycobacterium bovis is the causative agent of bovine tuberculosis (BTB, the pathogen responsible for serious economic impact on the livestock sector. In order to obtain data on isolated M. bovis strains and assist in the control and eradication program for BTB, a cross sectional descriptive molecular epidemiology study in the Brazilian Midwest was conducted. Through spoligotyping and 24-loci MIRU-VNTR methods, 37 clinical isolates of M. bovis circulating in the region were analyzed, 10 isolated from the state of Mato Grosso, 12 from the state of Mato Grosso do Sul and 15 from the state of Goiás. The spoligotyping analysis identified 10 distinct M. bovis profiles (SB0121 n = 14, SB0295 n = 6, SB0140 n = 6, SB0881 n = 3, SB1144 n = 2, SB1145 n = 2, SB0134 n = 1, SB1050 n = 1, SB1055 n = 1, SB1136 n = 1 grouped in six clusters and four orphan patterns. The MIRU-VNTR 24-loci grouped the same isolates in six clusters and 22 unique orphan patterns, showing higher discriminatory power than spoligotyping. When associating the results of both techniques, the isolates were grouped in five clusters and 24 unique M. bovis profiles. Among the 24-loci MIRU-VNTR evaluated, two, ETR-A and QUB 11b loci, showed high discriminatory ability (h = ≥ 0.50, while MIRU 16, MIRU 27, ETR-B, ETR-C, Mtub21 and QUB 26 loci showed moderate ability (h = 0.33 or h = 0.49 and were the most effective in evaluating the genotypic similarities among the clinical M. bovis isolate samples. Herein, the 29 patterns found amongst the 37 isolates of M. bovis circulating in the Brazilian Midwest can be due to the animal movement between regions, municipalities and farms, thus causing the spread of various M. bovis strains in herds from Midwest Brazil.

Dictionary of scientific units including dimensionless numbers and scales

National Research Council Canada - National Science Library

Jerrard, H.G; McNeill, D.B

1992-01-01

.... The text includes the most recently accepted values of all units. Several disciplines, which have in the past employed few scientific principles and the dictionary has been extended to include examples of these.

Optimal defense with variable number of overarching and individual protections

International Nuclear Information System (INIS)

Levitin, Gregory; Hausken, Kjell; Dai, Yuanshun

2014-01-01

The article considers a system consisting of identical elements. Each element can be protected individually. The groups of elements can have overarching protection. To destroy an element having both types of protections the attacker must always penetrate/destroy the overarching protection and then destroy the individual protection of the element. Both the attacker and the defender have limited resources. The resources needed to defend and attack the overarching protection are fixed, as is also the number of elements that can be protected by single overarching protection. The defender chooses the number of overarching protections and the number of individual protections within each protected group to minimize the expected damage caused by the attack. The attacker chooses the number of attacked overarching protections and after attacking the overarching protections it chooses the number of attacked elements to maximize the expected damage. The three period minmax game is formulated and an enumerative procedure for its solving is suggested. The influence of the game parameters on the optimal defense and attack strategies is discussed

Spatiotemporal Co-variability of Surface Climate for Renewable Energy across the Contiguous United States: Role of the North Atlantic Subtropical High

Science.gov (United States)

Doering, K.; Steinschneider, S.

2017-12-01

The variability of renewable energy supply and drivers of demand across space and time largely determines the energy balance within power systems with a high penetration of renewable technologies. This study examines the joint spatiotemporal variability of summertime climate linked to renewable energy production (precipitation, wind speeds, insolation) and energy demand (temperature) across the contiguous United States (CONUS) between 1948 and 2015. Canonical correlation analysis is used to identify the major modes of joint variability between summer wind speeds and precipitation and related patterns of insolation and temperature. Canonical variates are then related to circulation anomalies to identify common drivers of the joint modes of climate variability. Results show that the first two modes of joint variability between summer wind speeds and precipitation exhibit pan-US dipole patterns with centers of action located in the eastern and central CONUS. Temperature and insolation also exhibit related US-wide dipoles. The relationship between canonical variates and lower-tropospheric geopotential height indicates that these modes are related to variability in the North Atlantic subtropical high (NASH). This insight can inform optimal strategies for siting renewables in an interconnected electric grid, and has implications for the impacts of climate variability and change on renewable energy systems.

DEVELOPMENT OF A MULTIPLE-LOCUS VARIABLE NUMBER OF TANDEM REPEAT ANALYSIS (MLVA FOR HELICOBACTER PYLORI AND ITS APPLICATION TO HELICOBACTER PYLORI ISOLATES FROM ROSTOV REGION,RUSSIA

Directory of Open Access Journals (Sweden)

Sorokin VM

2012-09-01

Full Text Available Stomach infection with Helicobacter pylori (H. pylori is the second most common infectious disease of humans. The severe pathological consequences of this infection include gastric and duodenal ulcer disease, the development of gastric mucosal atrophy, gastric carcinoma, and, more rarely, malignant tumors of the lymphoma. H. pylori infections cause very high morbidity and mortality and are of particular concern in developing countries, where H. pylori prevalences as high as 90% have been reported. The population of H. pylori shows a high genomic variability among isolates. And the polymorphism of repeat-units of genomics had participated the important process of evolution. A variety of molecular typing tools have been developed to access genetic relatedness in H. pylori isolates. However, there is still no standard genotyping system of this bacterium. The MLVA (Multi-Locus of Variable number of tandem repeat Analysis method is useful for performing phylogenetic analysis and is widely used in bacteria genotyping; however, there's little application in H. pylori analysis. This article is the first application of the MLVA method to investigate H. pylori isolates in Russia. MLVA of 4 VNTR loci with high discrimination power based on 10 candidates were performed on a collection of 22 strains of H. pylori which originated from Rostov region of Russia. This method provides a starting point on which improvements to the method and comparisons to other techniques can be made.

Lack of support for a role of the insulin gene variable number of tandem repeats minisatellite (INS-VNTR) locus in fetal growth or type 2 diabetes-related intermediate traits in United Kingdom populations.

Science.gov (United States)

Mitchell, Simon M S; Hattersley, Andrew T; Knight, Beatrice; Turner, Tina; Metcalf, Bradley S; Voss, Linda D; Davies, David; McCarthy, Anne; Wilkin, Terence J; Smith, George Davey; Ben-Shlomo, Yoav; Frayling, Timothy M

2004-01-01

The insulin gene variable number of tandem repeats minisatellite (INS-VNTR) class III allele is associated with altered fetal growth, type 2 diabetes risk (especially when paternally inherited), and insulin and IGF2 gene expression. Further studies are needed to establish the role of the INS-VNTR in fetal growth and assess whether its effects depend on the parent of origin. We analyzed the INS-VNTR-linked -23 Hph1 polymorphism in 2283 subjects, comprising 1184 children and 1099 parents. There were no differences (P VNTR was nominally associated (P VNTR in fetal growth and nominal association with type 2 diabetes-related intermediate traits.

Optimization of Standard In-House 24-Locus Variable-Number Tandem-Repeat Typing for Mycobacterium tuberculosis and Its Direct Application to Clinical Material

NARCIS (Netherlands)

de Beer, Jessica L.; Akkerman, Onno W.; Schurch, Anita C.; Mulder, Arnout; van der Werf, Tjip S.; van der Zanden, Adri G. M.; van Ingen, Jakko; van Soolingen, Dick

Variable-number tandem-repeat (VNTR) typing with a panel of 24 loci is the current gold standard in the molecular typing of Mycobacterium tuberculosis complex isolates. However, because of technical problems, a part of the loci often cannot be amplified by multiplex PCRs. Therefore, a considerable

Up-scaling of multi-variable flood loss models from objects to land use units at the meso-scale

Directory of Open Access Journals (Sweden)

H. Kreibich

2016-05-01

Full Text Available Flood risk management increasingly relies on risk analyses, including loss modelling. Most of the flood loss models usually applied in standard practice have in common that complex damaging processes are described by simple approaches like stage-damage functions. Novel multi-variable models significantly improve loss estimation on the micro-scale and may also be advantageous for large-scale applications. However, more input parameters also reveal additional uncertainty, even more in upscaling procedures for meso-scale applications, where the parameters need to be estimated on a regional area-wide basis. To gain more knowledge about challenges associated with the up-scaling of multi-variable flood loss models the following approach is applied: Single- and multi-variable micro-scale flood loss models are up-scaled and applied on the meso-scale, namely on basis of ATKIS land-use units. Application and validation is undertaken in 19 municipalities, which were affected during the 2002 flood by the River Mulde in Saxony, Germany by comparison to official loss data provided by the Saxon Relief Bank (SAB.In the meso-scale case study based model validation, most multi-variable models show smaller errors than the uni-variable stage-damage functions. The results show the suitability of the up-scaling approach, and, in accordance with micro-scale validation studies, that multi-variable models are an improvement in flood loss modelling also on the meso-scale. However, uncertainties remain high, stressing the importance of uncertainty quantification. Thus, the development of probabilistic loss models, like BT-FLEMO used in this study, which inherently provide uncertainty information are the way forward.

A variable turbulent Prandtl and Schmidt number model study for scramjet applications

Science.gov (United States)

Keistler, Patrick

A turbulence model that allows for the calculation of the variable turbulent Prandtl (Prt) and Schmidt (Sct) numbers as part of the solution is presented. The model also accounts for the interactions between turbulence and chemistry by modeling the corresponding terms. Four equations are added to the baseline k-zeta turbulence model: two equations for enthalpy variance and its dissipation rate to calculate the turbulent diffusivity, and two equations for the concentrations variance and its dissipation rate to calculate the turbulent diffusion coefficient. The underlying turbulence model already accounts for compressibility effects. The variable Prt /Sct turbulence model is validated and tuned by simulating a wide variety of experiments. Included in the experiments are two-dimensional, axisymmetric, and three-dimensional mixing and combustion cases. The combustion cases involved either hydrogen and air, or hydrogen, ethylene, and air. Two chemical kinetic models are employed for each of these situations. For the hydrogen and air cases, a seven species/seven reaction model where the reaction rates are temperature dependent and a nine species/nineteen reaction model where the reaction rates are dependent on both pressure and temperature are used. For the cases involving ethylene, a 15 species/44 reaction reduced model that is both pressure and temperature dependent is used, along with a 22 species/18 global reaction reduced model that makes use of the quasi-steady-state approximation. In general, fair to good agreement is indicated for all simulated experiments. The turbulence/chemistry interaction terms are found to have a significant impact on flame location for the two-dimensional combustion case, with excellent experimental agreement when the terms are included. In most cases, the hydrogen chemical mechanisms behave nearly identically, but for one case, the pressure dependent model would not auto-ignite at the same conditions as the experiment and the other

Variable Linezolid Exposure in Intensive Care Unit Patients-Possible Role of Drug-Drug Interactions.

Science.gov (United States)

Töpper, Christoph; Steinbach, Cathérine L; Dorn, Christoph; Kratzer, Alexander; Wicha, Sebastian G; Schleibinger, Michael; Liebchen, Uwe; Kees, Frieder; Salzberger, Bernd; Kees, Martin G

2016-10-01

Standard doses of linezolid may not be suitable for all patient groups. Intensive care unit (ICU) patients in particular may be at risk of inadequate concentrations. This study investigated variability of drug exposure and its potential sources in this population. Plasma concentrations of linezolid were determined by high-performance liquid chromatography in a convenience sample of 20 ICU patients treated with intravenous linezolid 600 mg twice daily. Ultrafiltration applying physiological conditions (pH 7.4/37°C) was used to determine the unbound fraction. Individual pharmacokinetic (PK) parameters were estimated by population PK modeling. As measures of exposure to linezolid, area under the concentration-time curve (AUC) and trough concentrations (Cmin) were calculated and compared with published therapeutic ranges (AUC 200-400 mg*h/L, Cmin 2-10 mg/L). Coadministered inhibitors or inducers of cytochrome P450 and/or P-glycoprotein were noted. Data from 18 patients were included into the PK evaluation. Drug exposure was highly variable (median, range: AUC 185, 48-618 mg*h/L, calculated Cmin 2.92, 0.0062-18.9 mg/L), and only a minority of patients had values within the target ranges (6 and 7, respectively). AUC and Cmin were linearly correlated (R = 0.98), and classification of patients (underexposed/within therapeutic range/overexposed) according to AUC or Cmin was concordant in 15 cases. Coadministration of inhibitors was associated with a trend to higher drug exposure, whereas 3 patients treated with levothyroxine showed exceedingly low drug exposure (AUC ∼60 mg*h/L, Cmin linezolid is highly variable and difficult to predict in ICU patients, and therapeutic drug monitoring seems advisable. PK drug-drug interactions might partly be responsible and should be further investigated; protein binding appears to be stable and irrelevant.

Variability and decline in the number of severe tropical cyclones making land-fall over eastern Australia since the late nineteenth century

Energy Technology Data Exchange (ETDEWEB)

Callaghan, Jeff [Bureau of Meteorology, Brisbane (Australia); Power, Scott B. [Bureau of Meteorology, Centre for Australian Weather and Climate Research, GPO Box 1289, Melbourne (Australia)

2011-08-15

Recent studies have raised concerns that tropical cyclones (TCs), particularly severe TCs, have become more frequent in many places in response to global warming. Other studies discuss errors in TC data that can cause large inaccuracies in some of the observed trends. Additional studies conclude that TCs are likely to become more intense in the future in response to global warming, while regional modelling studies for the south-west Pacific near north-eastern Australia project an intensification of TCs and either a decrease or no change in TC numbers. Here we describe and use a new data base of severe land-falling TCs for eastern Australia derived from numerous historical sources, that has taken over a decade to develop. It provides one of the world's longest reliable records of tropical cyclone activity, and allows us to document changes over much longer periods than has been done previously for the Southern Hemisphere. Land-fall numbers are shown to vary a great deal on interannual, decadal and longer time-scales. The interannual variability is consistent with previous studies using much shorter data sets: land-fall numbers are well-simulated as a Poisson process and are modulated by the El Nino-Southern Oscillation (ENSO). Land-falls occurred almost twice as often in La Nina years as they did in El Nino years, and multiple land-falls only occurred during La Nina years. The statistical link between land-falls and pre-season values of the Southern Oscillation Index provides a modest predictive capability. Decadal variability in ENSO drives some of the decadal variability in land-fall numbers. The sign and magnitude of trends calculated over 30 years periods vary substantially, highlighting that caution needs to be taken in making inferences about trends based on e.g. satellite era data only. The linear trend in the number of severe TCs making land-fall over eastern Australia declined from about 0.45 TCs/year in the early 1870s to about 0.17 TCs/year in recent

A novel multiple locus variable number of tandem repeat (VNTR) analysis (MLVA) method for Propionibacterium acnes.

Science.gov (United States)

Hauck, Yolande; Soler, Charles; Gérôme, Patrick; Vong, Rithy; Macnab, Christine; Appere, Géraldine; Vergnaud, Gilles; Pourcel, Christine

2015-07-01

Propionibacterium acnes plays a central role in the pathogenesis of acne and is responsible for severe opportunistic infections. Numerous typing schemes have been developed that allow the identification of phylotypes, but they are often insufficient to differentiate subtypes. To better understand the genetic diversity of this species and to perform epidemiological analyses, high throughput discriminant genotyping techniques are needed. Here we describe the development of a multiple locus variable number of tandem repeats (VNTR) analysis (MLVA) method. Thirteen VNTRs were identified in the genome of P. acnes and were used to genotype a collection of clinical isolates. In addition, publically available sequencing data for 102 genomes were analyzed in silico, providing an MLVA genotype. The clustering of MLVA data was in perfect congruence with whole genome based clustering. Analysis of the clustered regularly interspaced short palindromic repeat (CRISPR) element uncovered new spacers, a supplementary source of genotypic information. The present MLVA13 scheme and associated internet database represents a first line genotyping assay to investigate large number of isolates. Particular strains may then be submitted to full genome sequencing in order to better analyze their pathogenic potential. Copyright © 2015 Elsevier B.V. All rights reserved.

Factors affecting temporal variability of arsenic in groundwater used for drinking water supply in the United States.

Science.gov (United States)

Ayotte, Joseph D; Belaval, Marcel; Olson, Scott A; Burow, Karen R; Flanagan, Sarah M; Hinkle, Stephen R; Lindsey, Bruce D

2015-02-01

The occurrence of arsenic in groundwater is a recognized environmental hazard with worldwide importance and much effort has been focused on surveying and predicting where arsenic occurs. Temporal variability is one aspect of this environmental hazard that has until recently received less attention than other aspects. For this study, we analyzed 1245 wells with two samples per well. We suggest that temporal variability, often reported as affecting very few wells, is perhaps a larger issue than it appears and has been overshadowed by datasets with large numbers of non-detect data. Although there was only a slight difference in arsenic concentration variability among samples from public and private wells (p=0.0452), the range of variability was larger for public than for private wells. Further, we relate the variability we see to geochemical factors-primarily variability in redox-but also variability in major-ion chemistry. We also show that in New England there is a weak but statistically significant indication that seasonality may have an effect on concentrations, whereby concentrations in the first two quarters of the year (January-June) are significantly lower than in the second two quarters (July-December) (pgroundwater levels. It is possible that this difference in arsenic concentrations is related to groundwater level changes, pumping stresses, evapotranspiration effects, or perhaps mixing of more oxidizing, lower pH recharge water in wetter months. Focusing on the understanding the geochemical conditions in aquifers where arsenic concentrations are concerns and causes of geochemical changes in the groundwater environment may lead to a better understanding of where and by how much arsenic will vary over time. Published by Elsevier B.V.

Interhospital Variability in Perioperative Red Blood Cell Ordering Patterns in United States Pediatric Surgical Patients.

Science.gov (United States)

Thompson, Rachel M; Thurm, Cary W; Rothstein, David H

2016-10-01

To evaluate perioperative red blood cell (RBC) ordering and interhospital variability patterns in pediatric patients undergoing surgical interventions at US children's hospitals. This is a multicenter cross-sectional study of children aged blood type and crossmatch were included when done on the day before or the day of the surgical procedure. The RBC transfusions included were those given on the day of or the day after surgery. The type and crossmatch-to-transfusion ratio (TCTR) was calculated for each surgical procedure. An adjusted model for interhospital variability was created to account for variation in patient population by age, sex, race/ethnicity, payer type, and presence/number of complex chronic conditions (CCCs) per patient. A total of 357 007 surgical interventions were identified across all participating hospitals. Blood type and crossmatch was performed 55 632 times, and 13 736 transfusions were provided, for a TCTR of 4:1. There was an association between increasing age and TCTR (R(2) = 0.43). Patients with multiple CCCs had lower TCTRs, with a stronger relationship (R(2) = 0.77). There was broad variability in adjusted TCTRs among hospitals (range, 2.5-25). The average TCTR in US children's hospitals was double that of adult surgical data, and was associated with wide interhospital variability. Age and the presence of CCCs markedly influenced this ratio. Studies to evaluate optimal preoperative RBC ordering and standardization of practices could potentially decrease unnecessary costs and wasted blood. Copyright © 2016 Elsevier Inc. All rights reserved.

Optimizing landslide susceptibility zonation: Effects of DEM spatial resolution and slope unit delineation on logistic regression models

Science.gov (United States)

Schlögel, R.; Marchesini, I.; Alvioli, M.; Reichenbach, P.; Rossi, M.; Malet, J.-P.

2018-01-01

We perform landslide susceptibility zonation with slope units using three digital elevation models (DEMs) of varying spatial resolution of the Ubaye Valley (South French Alps). In so doing, we applied a recently developed algorithm automating slope unit delineation, given a number of parameters, in order to optimize simultaneously the partitioning of the terrain and the performance of a logistic regression susceptibility model. The method allowed us to obtain optimal slope units for each available DEM spatial resolution. For each resolution, we studied the susceptibility model performance by analyzing in detail the relevance of the conditioning variables. The analysis is based on landslide morphology data, considering either the whole landslide or only the source area outline as inputs. The procedure allowed us to select the most useful information, in terms of DEM spatial resolution, thematic variables and landslide inventory, in order to obtain the most reliable slope unit-based landslide susceptibility assessment.

Large-area landslide susceptibility with optimized slope-units

Science.gov (United States)

Alvioli, Massimiliano; Marchesini, Ivan; Reichenbach, Paola; Rossi, Mauro; Ardizzone, Francesca; Fiorucci, Federica; Guzzetti, Fausto

2017-04-01

A Slope-Unit (SU) is a type of morphological terrain unit bounded by drainage and divide lines that maximize the within-unit homogeneity and the between-unit heterogeneity across distinct physical and geographical boundaries [1]. Compared to other terrain subdivisions, SU are morphological terrain unit well related to the natural (i.e., geological, geomorphological, hydrological) processes that shape and characterize natural slopes. This makes SU easily recognizable in the field or in topographic base maps, and well suited for environmental and geomorphological analysis, in particular for landslide susceptibility (LS) modelling. An optimal subdivision of an area into a set of SU depends on multiple factors: size and complexity of the study area, quality and resolution of the available terrain elevation data, purpose of the terrain subdivision, scale and resolution of the phenomena for which SU are delineated. We use the recently developed r.slopeunits software [2,3] for the automatic, parametric delineation of SU within the open source GRASS GIS based on terrain elevation data and a small number of user-defined parameters. The software provides subdivisions consisting of SU with different shapes and sizes, as a function of the input parameters. In this work, we describe a procedure for the optimal selection of the user parameters through the production of a large number of realizations of the LS model. We tested the software and the optimization procedure in a 2,000 km2 area in Umbria, Central Italy. For LS zonation we adopt a logistic regression model implemented in an well-known software [4,5], using about 50 independent variables. To select the optimal SU partition for LS zonation, we want to define a metric which is able to quantify simultaneously: (i) slope-unit internal homogeneity (ii) slope-unit external heterogeneity (iii) landslide susceptibility model performance. To this end, we define a comprehensive objective function S, as the product of three

Efficient DoA Tracking of Variable Number of Moving Stochastic EM Sources in Far-Field Using PNN-MLP Model

Directory of Open Access Journals (Sweden)

Zoran Stanković

2015-01-01

Full Text Available An efficient neural network-based approach for tracking of variable number of moving electromagnetic (EM sources in far-field is proposed in the paper. Electromagnetic sources considered here are of stochastic radiation nature, mutually uncorrelated, and at arbitrary angular distance. The neural network model is based on combination of probabilistic neural network (PNN and the Multilayer Perceptron (MLP networks and it performs real-time calculations in two stages, determining at first the number of moving sources present in an observed space sector in specific moments in time and then calculating their angular positions in azimuth plane. Once successfully trained, the neural network model is capable of performing an accurate and efficient direction of arrival (DoA estimation within the training boundaries which is illustrated on the appropriate example.

[Intel random number generator-based true random number generator].

Science.gov (United States)

Huang, Feng; Shen, Hong

2004-09-01

To establish a true random number generator on the basis of certain Intel chips. The random numbers were acquired by programming using Microsoft Visual C++ 6.0 via register reading from the random number generator (RNG) unit of an Intel 815 chipset-based computer with Intel Security Driver (ISD). We tested the generator with 500 random numbers in NIST FIPS 140-1 and X(2) R-Squared test, and the result showed that the random number it generated satisfied the demand of independence and uniform distribution. We also compared the random numbers generated by Intel RNG-based true random number generator and those from the random number table statistically, by using the same amount of 7500 random numbers in the same value domain, which showed that the SD, SE and CV of Intel RNG-based random number generator were less than those of the random number table. The result of u test of two CVs revealed no significant difference between the two methods. Intel RNG-based random number generator can produce high-quality random numbers with good independence and uniform distribution, and solves some problems with random number table in acquisition of the random numbers.

First insights into the molecular epidemiology of tuberculosis in Croatia during a three-year period, 2009 to 2011.

Science.gov (United States)

Zmak, Ljiljana; Obrovac, Mihaela; Katalinic Jankovic, Vera

2014-02-01

Mycobacterium tuberculosis still represents a serious cause of morbidity and mortality worldwide. The aim of this study was to determine the transmission rate and genetic lineages of M. tuberculosis circulating in Croatia during a 3-y period, between 2009 and 2011. A total of 1587 M. tuberculosis strains (1 strain per tuberculosis patient) isolated in Croatia from 2009 to 2011 were genotyped using 15-locus mycobacterial interspersed repetitive units-variable number of tandem repeats (MIRU-VNTR) analysis. The majority of tested isolates (66.73%) belonged to the Euro-American global lineage. The most prevalent sub-lineages were Haarlem (48.64%), followed by S (6.05%), Cameroon (3.72%), and Latin American-Mediterranean (3.4%). Among the total 1587 tested isolates, 996 (63%) were included in 1 of 236 clusters. The cluster size ranged from 2 (114 clusters) to 45 (1 cluster) patients, the mean cluster size being 4.2. These results indicate that 47.83% of tuberculosis cases during the period analyzed were the result of recent transmission. The most prevalent global lineage in Croatia is Euro-American (sub-lineages Haarlem, S, Cameroon, and Latin American-Mediterranean). The high clustering rate and high medium clustering size of 4.2 tuberculosis cases could indicate a possible failure in interrupting the transmission of infection and points to the need for improvements in national and local tuberculosis control activities. This is the first study describing the molecular epidemiology of tuberculosis in Croatia.

A Predominant Variable-Number Tandem-Repeat Cluster of Mycobacterium tuberculosis Isolates among Asylum Seekers in the Netherlands and Denmark, Deciphered by Whole-Genome Sequencing.

NARCIS (Netherlands)

Jajou, Rana; de Neeling, Albert; Rasmussen, Erik Michael; Norman, Anders; Mulder, Arnout; van Hunen, Rianne; de Vries, Gerard; Haddad, Walid; Anthony, Richard; Lillebaek, Troels; van der Hoek, Wim; van Soolingen, Dick

In many countries,Mycobacterium tuberculosisisolates are routinely subjected to variable-number tandem-repeat (VNTR) typing to investigateM. tuberculosistransmission. Unexpectedly, cross-border clusters were identified among African refugees in the Netherlands and Denmark, although transmission in

Multi-locus variable-number tandem repeat profiling of Salmonella enterica serovar Typhi isolates from blood cultures and gallbladder specimens from Makassar, South-Sulawesi, Indonesia.

Directory of Open Access Journals (Sweden)

Mochammad Hatta

Full Text Available Multi-locus variable-number tandem repeat analysis differentiated 297 Salmonella enterica serovar Typhi blood culture isolates from Makassar in 76 genotypes and a single unique S. Typhi genotype was isolated from the cholecystectomy specimens of four patients with cholelithiasis. The high diversity in S. Typhi genotypes circulating in Makassar indicates that the number of carriers could be very large, which may complicate disease prevention and control.

Operational analysis of the coupling between a multi-effect distillation unit with thermal vapor compression and a Rankine cycle power block using variable nozzle thermocompressors

International Nuclear Information System (INIS)

Ortega-Delgado, Bartolomé; Cornali, Matteo; Palenzuela, Patricia; Alarcón-Padilla, Diego C.

2017-01-01

Highlights: •Variable nozzle steam ejectors are used for operation flexibility of MED plants. •The power block breaking points have been investigated by simulations in Thermoflex. •An operational model of the MED-TVC process is developed for part load operation. •Efficiency and fresh water production are studied at nominal and partial loads. -- Abstract: In Multi-Effect Distillation with Thermal Vapor Compression (MED-TVC) plants, fixed steam ejectors are usually designed for constant motive steam pressures. When these distillation units are integrated into Concentrating Solar Power (CSP) plants, the available motive steam pressure is normally lower than the design value (due to the partial load operation of the power cycle under different solar radiation conditions), being the efficiency of the steam ejectors drastically reduced. Also, it has a negative impact on the fresh water production from the desalination plant because of a decrease in the mass flow of the motive steam. All this can be avoided by using variable nozzle steam ejectors, which can adjust the mass flow rate of steam according to the variable pressure so that they are always operating with the maximum efficiency and therefore they can maintain the freshwater production of the desalination plant near to the nominal value. This work presents a study of the coupling between CSP plants and MED-TVC units using variable nozzle steam ejectors in a wide range of operating conditions (on and off-design). For this purpose, simulations of a Rankine cycle power block in a typical commercial CSP plant have been firstly performed at different thermal loads to investigate the operational limits that allow keeping the motive steam mass flow rates constant. Then, the efficiency and fresh water production of an MED-TVC unit coupled to the different extractions available at the CSP plant have been studied in a wide range of operating conditions, covering both nominal and partial loads. To this end, an

Poison control center - emergency number

Science.gov (United States)

For a POISON EMERGENCY call: 1-800-222-1222 ANYWHERE IN THE UNITED STATES This national hotline number will let you ... is a free and confidential service. All local poison control centers in the United States use this ...

Using variable combination population analysis for variable selection in multivariate calibration.

Science.gov (United States)

Yun, Yong-Huan; Wang, Wei-Ting; Deng, Bai-Chuan; Lai, Guang-Bi; Liu, Xin-bo; Ren, Da-Bing; Liang, Yi-Zeng; Fan, Wei; Xu, Qing-Song

2015-03-03

Variable (wavelength or feature) selection techniques have become a critical step for the analysis of datasets with high number of variables and relatively few samples. In this study, a novel variable selection strategy, variable combination population analysis (VCPA), was proposed. This strategy consists of two crucial procedures. First, the exponentially decreasing function (EDF), which is the simple and effective principle of 'survival of the fittest' from Darwin's natural evolution theory, is employed to determine the number of variables to keep and continuously shrink the variable space. Second, in each EDF run, binary matrix sampling (BMS) strategy that gives each variable the same chance to be selected and generates different variable combinations, is used to produce a population of subsets to construct a population of sub-models. Then, model population analysis (MPA) is employed to find the variable subsets with the lower root mean squares error of cross validation (RMSECV). The frequency of each variable appearing in the best 10% sub-models is computed. The higher the frequency is, the more important the variable is. The performance of the proposed procedure was investigated using three real NIR datasets. The results indicate that VCPA is a good variable selection strategy when compared with four high performing variable selection methods: genetic algorithm-partial least squares (GA-PLS), Monte Carlo uninformative variable elimination by PLS (MC-UVE-PLS), competitive adaptive reweighted sampling (CARS) and iteratively retains informative variables (IRIV). The MATLAB source code of VCPA is available for academic research on the website: http://www.mathworks.com/matlabcentral/fileexchange/authors/498750. Copyright © 2015 Elsevier B.V. All rights reserved.

The precision of mapping between number words and the approximate number system predicts children's formal math abilities.

Science.gov (United States)

Libertus, Melissa E; Odic, Darko; Feigenson, Lisa; Halberda, Justin

2016-10-01

Children can represent number in at least two ways: by using their non-verbal, intuitive approximate number system (ANS) and by using words and symbols to count and represent numbers exactly. Furthermore, by the time they are 5years old, children can map between the ANS and number words, as evidenced by their ability to verbally estimate numbers of items without counting. How does the quality of the mapping between approximate and exact numbers relate to children's math abilities? The role of the ANS-number word mapping in math competence remains controversial for at least two reasons. First, previous work has not examined the relation between verbal estimation and distinct subtypes of math abilities. Second, previous work has not addressed how distinct components of verbal estimation-mapping accuracy and variability-might each relate to math performance. Here, we addressed these gaps by measuring individual differences in ANS precision, verbal number estimation, and formal and informal math abilities in 5- to 7-year-old children. We found that verbal estimation variability, but not estimation accuracy, predicted formal math abilities, even when controlling for age, expressive vocabulary, and ANS precision, and that it mediated the link between ANS precision and overall math ability. These findings suggest that variability in the ANS-number word mapping may be especially important for formal math abilities. Copyright © 2016 Elsevier Inc. All rights reserved.

Variable number of tandem repeats of 9 Plasmodium vivax genes among Southeast Asian isolates.

Science.gov (United States)

Wang, Bo; Nyunt, Myat Htut; Yun, Seung-Gyu; Lu, Feng; Cheng, Yang; Han, Jin-Hee; Ha, Kwon-Soo; Park, Won Sun; Hong, Seok-Ho; Lim, Chae-Seung; Cao, Jun; Sattabongkot, Jetsumon; Kyaw, Myat Phone; Cui, Liwang; Han, Eun-Taek

2017-06-01

The variable number of tandem repeats (VNTRs) provides valuable information about both the functional and evolutionary aspects of genetic diversity. Comparative analysis of 3 Plasmodium falciparum genomes has shown that more than 9% of its open reading frames (ORFs) harbor VNTRs. Although microsatellites and VNTR genes of P. vivax were reported, the VNTR polymorphism of genes has not been examined widely. In this study, 230 P. vivax genes were analyzed for VNTRs by SERV, and 33 kinds of TR deletions or insertions from 29 P. vivax genes (12.6%) were found. Of these, 9 VNTR fragments from 8 P. vivax genes were used for PCR amplification and sequence analysis to examine the genetic diversity among 134 isolates from four Southeast Asian countries (China, Republic of Korea, Thailand, and Myanmar) with different malaria endemicity. We confirmed the existence of extensive polymorphism of VNTR fragments in field isolates. This detection provides several suitable markers for analysis of the molecular epidemiology of P. vivax field isolates. Copyright © 2017 Elsevier B.V. All rights reserved.

Motor unit number index (MUNIX) derivation from the relationship between the area and power of surface electromyogram: a computer simulation and clinical study

Science.gov (United States)

Miralles, Francesc

2018-06-01

Objective. The motor unit number index (MUNIX) is a technique based on the surface electromyogram (sEMG) that is gaining acceptance as a method for monitoring motor neuron loss, because it is reliable and produces less discomfort than other electrodiagnostic techniques having the same intended purpose. MUNIX assumes that the relationship between the area of sEMG obtained at increasing levels of muscle activation and the values of a variable called ‘ideal case motor unit count’ (ICMUC), defined as the product of the ratio between area and power of the compound muscle action potential (CMAP) by that of the sEMG, is described by a decreasing power function. Nevertheless, the reason for this comportment is unknown. The objective of this work is to investigate if the definition of MUNIX could derive from more basic properties of the sEMG. Approach. The CMAP and sEMG epochs obtained at different levels of muscle activation from (1) the abductor pollicis brevis (APB) muscle of persons with and without a carpal tunnel syndrome (CTS) and (2) from a computer model of sEMG generation previously published were analysed. Main results. MUNIX reflects the power relationship existing between the area and power of a sEMG. The exponent of this function was smaller in patients with motor CTS than in the rest of the subjects. The analysis of the relationship between the area and power of a sEMG could aid in distinguishing a MUNIX reduction due to a motoneuron loss from that due to a loss of muscle fibre. Significance. MUNIX is derived from the relationship between the area and power of a sEMG. This relationship changes when there is a loss of motor units (MUs), which partially explains the diagnostic sensibility of MUNIX. Although the reasons for this change are unknown, it could reflect an increase in the proportion of MUs of great amplitude.

Inclusive photoproduction of D*± mesons at next-to-leading order in the general-mass variable-flavor-number scheme

International Nuclear Information System (INIS)

Kniehl, B.A.; Kramer, G.; Schienbein, I.; Spiesberger, H.

2009-02-01

We discuss the inclusive production of D *± mesons in γp collisions at DESY HERA, based on a calculation at next-to-leading order in the general-mass variable-flavor-number scheme. In this approach, MS subtraction is applied in such a way that large logarithmic corrections are resummed in universal parton distribution and fragmentation functions and finite mass terms are taken into account. We present detailed numerical results for a comparison with data obtained at HERA and discuss various sources of theoretical uncertainties. (orig.)

Inclusive photoproduction of D{sup *{+-}} mesons at next-to-leading order in the general-mass variable-flavor-number scheme

Energy Technology Data Exchange (ETDEWEB)

Kniehl, B.A.; Kramer, G. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Schienbein, I. [Univ. Joseph Fourier/CNRS-IN2P3, INPG, Grenoble (France). Lab. de Physique Subatomique et de Cosmologie; Spiesberger, H. [Mainz Univ. (Germany). Inst. fuer Physik

2009-02-15

We discuss the inclusive production of D{sup *{+-}} mesons in {gamma}p collisions at DESY HERA, based on a calculation at next-to-leading order in the general-mass variable-flavor-number scheme. In this approach, MS subtraction is applied in such a way that large logarithmic corrections are resummed in universal parton distribution and fragmentation functions and finite mass terms are taken into account. We present detailed numerical results for a comparison with data obtained at HERA and discuss various sources of theoretical uncertainties. (orig.)

The number of pickers and stock-keeping unit arrangement on a uni-directional picking line

Directory of Open Access Journals (Sweden)

Hagspihl, Robert

2014-10-01

Full Text Available The order picking process is often the single largest expense in a distribution centre (DC. The DC considered in this paper uses a picking line configuration to perform order picking. The number of pickers in a picking line, and the initial arrangement of stock-keeping units (SKUs, are two important factors that affect the total completion time of the picking lines. In this paper, the picking line configuration is simulated with an agent-based approach to describe the behaviour of an individual picker. The simulation is then used to analyse the effect of the number of pickers and the SKU arrangement. Verification and validation of this model shows that the model represents the real-world picking line to a satisfactory degree. Marginal analysis (MA was chosen to determine a ‘good’ number of pickers by means of the simulation model. A look-up table is presented to provide decision support for the choice of a ‘good’ number of pickers to improve completion times of the picking line, for the properties of a specific picking line. The initial SKU arrangement on a picking line is shown to be a factor that can affect the level of picker congestion and the total completion time. The greedy ranking and partitioning (GRP and organ pipe arrangement (OPA techniques from the literature, as well as the historical SKU arrangements used by the retailer under consideration, were compared with the proposed classroom discipline heuristic (CDH for SKU arrangement. It was found that the CDH provides an more even spread of SKUs that are picked most frequently, thus decreasing congestion and total completion time.

The effects of competition on premiums: using United Healthcare's 2015 entry into Affordable Care Act's marketplaces as an instrumental variable.

Science.gov (United States)

Agirdas, Cagdas; Krebs, Robert J; Yano, Masato

2018-01-08

One goal of the Affordable Care Act is to increase insurance coverage by improving competition and lowering premiums. To facilitate this goal, the federal government enacted online marketplaces in the 395 rating areas spanning 34 states that chose not to establish their own state-run marketplaces. Few multivariate regression studies analyzing the effects of competition on premiums suffer from endogeneity, due to simultaneity and omitted variable biases. However, United Healthcare's decision to enter these marketplaces in 2015 provides the researcher with an opportunity to address this endogeneity problem. Exploiting the variation caused by United Healthcare's entry decision as an instrument for competition, we study the impact of competition on premiums during the first 2 years of these marketplaces. Combining panel data from five different sources and controlling for 12 variables, we find that one more insurer in a rating area leads to a 6.97% reduction in the second-lowest-priced silver plan premium, which is larger than the estimated effects in existing literature. Furthermore, we run a threshold analysis and find that competition's effects on premiums become statistically insignificant if there are four or more insurers in a rating area. These findings are robust to alternative measures of premiums, inclusion of a non-linear term in the regression models and a county-level analysis.

Exploratory Spectroscopy of Magnetic Cataclysmic Variables Candidates and Other Variable Objects

Energy Technology Data Exchange (ETDEWEB)

Oliveira, A. S.; Palhares, M. S. [IP and D, Universidade do Vale do Paraíba, 12244-000, São José dos Campos, SP (Brazil); Rodrigues, C. V.; Cieslinski, D.; Jablonski, F. J. [Divisão de Astrofísica, Instituto Nacional de Pesquisas Espaciais, 12227-010, São José dos Campos, SP (Brazil); Silva, K. M. G. [Gemini Observatory, Casilla 603, La Serena (Chile); Almeida, L. A. [Instituto de Astronomia, Geofísica e Ciências Atmosféricas, Universidade de São Paulo, 05508-900, São Paulo, SP (Brazil); Rodríguez-Ardila, A., E-mail: alexandre@univap.br [Laboratório Nacional de Astrofísica LNA/MCTI, 37504-364, Itajubá MG (Brazil)

2017-04-01

The increasing number of synoptic surveys made by small robotic telescopes, such as the photometric Catalina Real-Time Transient Survey (CRTS), provides a unique opportunity to discover variable sources and improves the statistical samples of such classes of objects. Our goal is the discovery of magnetic Cataclysmic Variables (mCVs). These are rare objects that probe interesting accretion scenarios controlled by the white-dwarf magnetic field. In particular, improved statistics of mCVs would help to address open questions on their formation and evolution. We performed an optical spectroscopy survey to search for signatures of magnetic accretion in 45 variable objects selected mostly from the CRTS. In this sample, we found 32 CVs, 22 being mCV candidates, 13 of which were previously unreported as such. If the proposed classifications are confirmed, it would represent an increase of 4% in the number of known polars and 12% in the number of known IPs. A fraction of our initial sample was classified as extragalactic sources or other types of variable stars by the inspection of the identification spectra. Despite the inherent complexity in identifying a source as an mCV, variability-based selection, followed by spectroscopic snapshot observations, has proved to be an efficient strategy for their discoveries, being a relatively inexpensive approach in terms of telescope time.

On the functional form of particle number size distributions: influence of particle source and meteorological variables

Science.gov (United States)

Cugerone, Katia; De Michele, Carlo; Ghezzi, Antonio; Gianelle, Vorne; Gilardoni, Stefania

2018-04-01

Particle number size distributions (PNSDs) have been collected periodically in the urban area of Milan, Italy, during 2011 and 2012 in winter and summer months. Moreover, comparable PNSD measurements were carried out in the rural mountain site of Oga-San Colombano (2250 m a.s.l.), Italy, during February 2005 and August 2011. The aerosol data have been measured through the use of optical particle counters in the size range 0.3-25 µm, with a time resolution of 1 min. The comparison of the PNSDs collected in the two sites has been done in terms of total number concentration, showing higher numbers in Milan (often exceeding 103 cm-3 in winter season) compared to Oga-San Colombano (not greater than 2×102 cm-3), as expected. The skewness-kurtosis plane has been used in order to provide a synoptic view, and select the best distribution family describing the empirical PNSD pattern. The four-parameter Johnson system-bounded distribution (called Johnson SB or JSB) has been tested for this aim, due to its great flexibility and ability to assume different shapes. The PNSD pattern has been found to be generally invariant under site and season changes. Nevertheless, several PNSDs belonging to the Milan winter season (generally more than 30 %) clearly deviate from the standard empirical pattern. The seasonal increase in the concentration of primary aerosols due to combustion processes in winter and the influence of weather variables throughout the year, such as precipitation and wind speed, could be considered plausible explanations of PNSD dynamics.

The Information Content of Financial and Economic Variables: Empirical Tests of Information Variables in Japan

OpenAIRE

Kengo Kato

1991-01-01

The main topic of this paper is "information variables" (or "indicators") of monetary policy, which work as criteria for setting the direction of monetary policy. After briefly surveying the notion and candidates of information variables, according to the studies mainly in the United States, empirical tests using Japan's data are conducted. It can be said that some information variables seem to be useful, but the results are mixed in general.

Comparative study of the variables for determining unit processing cost of irradiated food products in developing countries : case study of Ghana

International Nuclear Information System (INIS)

Banini, G.K; Emi-Reynolds, G.; Kassapu, S.N.

1997-01-01

A method for estimating unit cost of gamma treated food products in a developing country like Ghana is presented. The method employs the cost of cobalt source requirement, capital and operating costs, dose requirements etc. and relates these variables to various annual throughput at a gamma processing facility. In situations where the cost of foreign components or devices are required, the assumptions have been based on those of Kunstadt and Steeves. Otherwise, the prevailing conditions existing in Ghana have been used. The study reveals that the unit processing cost for gamma treatment foods in such a facility is between 8.0 to 147.2 US dollars per tonne. (author). 9 refs., 4 figs

Generalized Bernoulli-Hurwitz numbers and the universal Bernoulli numbers

International Nuclear Information System (INIS)

Ônishi, Yoshihiro

2011-01-01

The three fundamental properties of the Bernoulli numbers, namely, the von Staudt-Clausen theorem, von Staudt's second theorem, and Kummer's original congruence, are generalized to new numbers that we call generalized Bernoulli-Hurwitz numbers. These are coefficients in the power series expansion of a higher-genus algebraic function with respect to a suitable variable. Our generalization differs strongly from previous works. Indeed, the order of the power of the modulus prime in our Kummer-type congruences is exactly the same as in the trigonometric function case (namely, Kummer's own congruence for the original Bernoulli numbers), and as in the elliptic function case (namely, H. Lang's extension for the Hurwitz numbers). However, in other past results on higher-genus algebraic functions, the modulus was at most half of its value in these classical cases. This contrast is clarified by investigating the analogue of the three properties above for the universal Bernoulli numbers. Bibliography: 34 titles.

Generalized Bernoulli-Hurwitz numbers and the universal Bernoulli numbers

Energy Technology Data Exchange (ETDEWEB)

Onishi, Yoshihiro [Faculty of Education Human Sciences, University of Yamanashi, Takeda, Kofu (Japan)

2011-10-31

The three fundamental properties of the Bernoulli numbers, namely, the von Staudt-Clausen theorem, von Staudt's second theorem, and Kummer's original congruence, are generalized to new numbers that we call generalized Bernoulli-Hurwitz numbers. These are coefficients in the power series expansion of a higher-genus algebraic function with respect to a suitable variable. Our generalization differs strongly from previous works. Indeed, the order of the power of the modulus prime in our Kummer-type congruences is exactly the same as in the trigonometric function case (namely, Kummer's own congruence for the original Bernoulli numbers), and as in the elliptic function case (namely, H. Lang's extension for the Hurwitz numbers). However, in other past results on higher-genus algebraic functions, the modulus was at most half of its value in these classical cases. This contrast is clarified by investigating the analogue of the three properties above for the universal Bernoulli numbers. Bibliography: 34 titles.

The discovery, function and development of the variable number tandem repeats in different Mycobacterium species.

Science.gov (United States)

Sun, Zhaogang; Li, Weimin; Xu, Shaofa; Huang, Hairong

2016-09-01

The method of genotyping by variable number tandem repeats (VNTRs) facilitates the epidemiological studies of different Mycobacterium species worldwide. Until now, the VNTR method is not fully understood, for example, its discovery, function and classification. The inconsistent nomenclature and terminology of VNTR is especially confusing. In this review, we first describe in detail the VNTRs in Mycobacterium tuberculosis (M. tuberculosis), as this pathogen resulted in more deaths than any other microbial pathogen as well as for which extensive studies of VNTRs were carried out, and then we outline the recent progress of the VNTR-related epidemiological research in several other Mycobacterium species, such as M. abscessus, M. africanum, M. avium, M. bovis, M. canettii, M. caprae, M. intracellulare, M. leprae, M. marinum, M. microti, M. pinnipedii and M. ulcerans from different countries and regions. This article is aimed mainly at the practical notes of VNTR to help the scientists in better understanding and performing this method.

Inclusive photoproduction of bottom quarks for low and medium pT in the general-mass variable-flavour-number scheme

International Nuclear Information System (INIS)

Kramer, G.; Spiesberger, H.; Cape Town Univ., Rondebosch

2015-09-01

We present predictions for b-quark production in photoproduction and compare with experimental data from HERA. Our theoretical predictions are obtained at next-to-leading-order in the general-mass variable-flavor-number scheme, an approach which takes into account the finite mass of the b quarks. We use realistic evolved nonperturbative fragmentation functions obtained from fits to e + e - data. We find in general good agreement of data with both the GM-VFNS and the FFNS calculations, while the more precise ZEUS data seem to prefer the GM-VFNS predictions.

First Worldwide Proficiency Study on Variable-Number Tandem-Repeat Typing of Mycobacterium tuberculosis Complex Strains

Science.gov (United States)

de Beer, Jessica L.; Kremer, Kristin; Ködmön, Csaba; Supply, Philip

2012-01-01

Although variable-number tandem-repeat (VNTR) typing has gained recognition as the new standard for the DNA fingerprinting of Mycobacterium tuberculosis complex (MTBC) isolates, external quality control programs have not yet been developed. Therefore, we organized the first multicenter proficiency study on 24-locus VNTR typing. Sets of 30 DNAs of MTBC strains, including 10 duplicate DNA samples, were distributed among 37 participating laboratories in 30 different countries worldwide. Twenty-four laboratories used an in-house-adapted method with fragment sizing by gel electrophoresis or an automated DNA analyzer, nine laboratories used a commercially available kit, and four laboratories used other methods. The intra- and interlaboratory reproducibilities of VNTR typing varied from 0% to 100%, with averages of 72% and 60%, respectively. Twenty of the 37 laboratories failed to amplify particular VNTR loci; if these missing results were ignored, the number of laboratories with 100% interlaboratory reproducibility increased from 1 to 5. The average interlaboratory reproducibility of VNTR typing using a commercial kit was better (88%) than that of in-house-adapted methods using a DNA analyzer (70%) or gel electrophoresis (50%). Eleven laboratories using in-house-adapted manual typing or automated typing scored inter- and intralaboratory reproducibilities of 80% or higher, which suggests that these approaches can be used in a reliable way. In conclusion, this first multicenter study has documented the worldwide quality of VNTR typing of MTBC strains and highlights the importance of international quality control to improve genotyping in the future. PMID:22170917

The Precision of Mapping Between Number Words and the Approximate Number System Predicts Children’s Formal Math Abilities

Science.gov (United States)

Libertus, Melissa E.; Odic, Darko; Feigenson, Lisa; Halberda, Justin

2016-01-01

Children can represent number in at least two ways: by using their non-verbal, intuitive Approximate Number System (ANS), and by using words and symbols to count and represent numbers exactly. Further, by the time they are five years old, children can map between the ANS and number words, as evidenced by their ability to verbally estimate numbers of items without counting. How does the quality of the mapping between approximate and exact numbers relate to children’s math abilities? The role of the ANS-number word mapping in math competence remains controversial for at least two reasons. First, previous work has not examined the relation between verbal estimation and distinct subtypes of math abilities. Second, previous work has not addressed how distinct components of verbal estimation – mapping accuracy and variability – might each relate to math performance. Here, we address these gaps by measuring individual differences in ANS precision, verbal number estimation, and formal and informal math abilities in 5- to 7-year-old children. We found that verbal estimation variability, but not estimation accuracy, predicted formal math abilities even when controlling for age, expressive vocabulary, and ANS precision, and that it mediated the link between ANS precision and overall math ability. These findings suggest that variability in the ANS-number word mapping may be especially important for formal math abilities. PMID:27348475

Molecular Strain Typing of Mycobacterium tuberculosis: a Review of Frequently Used Methods

Science.gov (United States)

2016-01-01

Tuberculosis, caused by the bacterium Mycobacterium tuberculosis, remains one of the most serious global health problems. Molecular typing of M. tuberculosis has been used for various epidemiologic purposes as well as for clinical management. Currently, many techniques are available to type M. tuberculosis. Choosing the most appropriate technique in accordance with the existing laboratory conditions and the specific features of the geographic region is important. Insertion sequence IS6110-based restriction fragment length polymorphism (RFLP) analysis is considered the gold standard for the molecular epidemiologic investigations of tuberculosis. However, other polymerase chain reaction-based methods such as spacer oligonucleotide typing (spoligotyping), which detects 43 spacer sequence-interspersing direct repeats (DRs) in the genomic DR region; mycobacterial interspersed repetitive units–variable number tandem repeats, (MIRU-VNTR), which determines the number and size of tandem repetitive DNA sequences; repetitive-sequence-based PCR (rep-PCR), which provides high-throughput genotypic fingerprinting of multiple Mycobacterium species; and the recently developed genome-based whole genome sequencing methods demonstrate similar discriminatory power and greater convenience. This review focuses on techniques frequently used for the molecular typing of M. tuberculosis and discusses their general aspects and applications. PMID:27709842

Radiocaesium variability in upland sheep flocks

Energy Technology Data Exchange (ETDEWEB)

Beresford, N.A

2002-07-01

Following the 1986 Chernobyl accident large areas of uplands in the United Kingdom were contaminated by radiocaesium. Consequently, the level of radiocaesium in the tissues of some sheep exceeded 1000 Bq kg{sup -1} fresh weight This is the limit adopted within the UK above which meat cannot enter the food chain. In 1986, restrictions were placed on the movement and slaughter of sheep in areas of west Cumbria, north Wales and Scotland. Whilst the number of farms under restriction has reduced considerably, some still remain restricted in 2002. Although a number of workers had noted considerable variability between the radiocaesium activities of individuals within sheep flocks there had been no analyses of causal effects. The work described here, combined studies on three upland farms within west Cumbria with controlled feeding experiments, to systematically assess the parameters which may contribute to such variability. Results from all three farms demonstrate a temporally consistent ranking of the {sup 137}Cs activity concentration of individual sheep within the study flocks. As there was also a correlation between the {sup 137}Cs activity concentration of ewes and their pre-weaned lambs it is likely that the same ewes are producing lambs in excess of the intervention limit in subsequent years. It is difficult to generalise as to which factors will contribute to {sup 137}Cs variability within a given upland flock; factors contributing to variation were not consistent between the study farms. However, the location grazed and/or vegetation selected by animals was a causal factor to the observed variability at all three farms. The transfer of radiocaesium from the diet to muscle of sheep was found to be determined by live-weight change and dry matter intake. Subsequent studies have suggested that protein turnover may be a potential mechanism for the relationship between dry matter intake and radiocaesium transfer. This hypothesis is supported by current understanding

Radiocaesium variability in upland sheep flocks

International Nuclear Information System (INIS)

Beresford, N.A.

2002-01-01

Following the 1986 Chernobyl accident large areas of uplands in the United Kingdom were contaminated by radiocaesium. Consequently, the level of radiocaesium in the tissues of some sheep exceeded 1000 Bq kg -1 fresh weight This is the limit adopted within the UK above which meat cannot enter the food chain. In 1986, restrictions were placed on the movement and slaughter of sheep in areas of west Cumbria, north Wales and Scotland. Whilst the number of farms under restriction has reduced considerably, some still remain restricted in 2002. Although a number of workers had noted considerable variability between the radiocaesium activities of individuals within sheep flocks there had been no analyses of causal effects. The work described here, combined studies on three upland farms within west Cumbria with controlled feeding experiments, to systematically assess the parameters which may contribute to such variability. Results from all three farms demonstrate a temporally consistent ranking of the 137 Cs activity concentration of individual sheep within the study flocks. As there was also a correlation between the 137 Cs activity concentration of ewes and their pre-weaned lambs it is likely that the same ewes are producing lambs in excess of the intervention limit in subsequent years. It is difficult to generalise as to which factors will contribute to 137 Cs variability within a given upland flock; factors contributing to variation were not consistent between the study farms. However, the location grazed and/or vegetation selected by animals was a causal factor to the observed variability at all three farms. The transfer of radiocaesium from the diet to muscle of sheep was found to be determined by live-weight change and dry matter intake. Subsequent studies have suggested that protein turnover may be a potential mechanism for the relationship between dry matter intake and radiocaesium transfer. This hypothesis is supported by current understanding of protein-dry matter

Benchmarking Variable Selection in QSAR.

Science.gov (United States)

Eklund, Martin; Norinder, Ulf; Boyer, Scott; Carlsson, Lars

2012-02-01

Variable selection is important in QSAR modeling since it can improve model performance and transparency, as well as reduce the computational cost of model fitting and predictions. Which variable selection methods that perform well in QSAR settings is largely unknown. To address this question we, in a total of 1728 benchmarking experiments, rigorously investigated how eight variable selection methods affect the predictive performance and transparency of random forest models fitted to seven QSAR datasets covering different endpoints, descriptors sets, types of response variables, and number of chemical compounds. The results show that univariate variable selection methods are suboptimal and that the number of variables in the benchmarked datasets can be reduced with about 60 % without significant loss in model performance when using multivariate adaptive regression splines MARS and forward selection. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

[RECALMIN. Patient care in the internal medicine units of the Spanish national health system].

Science.gov (United States)

Zapatero Gaviria, A; Barba Martín, R; Román Sánchez, P; Casariego Vales, E; Diez Manglano, J; García Cors, M; Jusdado Ruiz-Capillas, J J; Suárez Fernández, C; Bernal, J L; Elola Somoza, F J

2016-05-01

To perform a situation analysis of the care provided by internal medicine units (IMUs) in Spain and to develop, based on this analysis, proposals for improving the quality of care in these units. A descriptive, cross-sectional study of the IMUs of general acute care hospitals of the Spanish National Health System (SNHS), with data referring to 2013. The study variables were collected via an ad hoc questionnaire. Of the total 260hospitals identified in the SNHS, 142responses were obtained from 139hospitals throughout Spain, which represents 53.5% of the IMUs in the SNHS. The mean number of internists per IMU was 14±8, with a mean rate of 7.2±3.3 internists per 100,000 inhabitants. In 2013, the average number of hospital discharges from the IMU was 2,987±2,066, and those discharged by internists was 232±107. Sixty-one percent of the IMUs had implemented an interconsultation unit, and 41% had implemented a systematic care program for complex chronic patients. Thirty-three percent of the IMUs conducted multidisciplinary rounds, and 60% of these IMUs planned the discharge. The 2013 RECALMIN survey revealed a number of important aspects of the organisation, structure and management of IMUs. The remarkable variability in the indicators of structure, activity and management probably reflect significant differences in efficiency and productivity, which therefore provide significant room for improvement. Copyright © 2016 Elsevier España, S.L.U. y Sociedad Española de Medicina Interna (SEMI). All rights reserved.

Associations between bolus infusion of hydrocortisone, glycemic variability and insulin infusion rate variability in critically Ill patients under moderate glycemic control

NARCIS (Netherlands)

van Hooijdonk, Roosmarijn T. M.; Binnekade, Jan M.; Bos, Lieuwe D. J.; Horn, Janneke; Juffermans, Nicole P.; Abu-Hanna, Ameen; Schultz, Marcus J.

2015-01-01

We retrospectively studied associations between bolus infusion of hydrocortisone and variability of the blood glucose level and changes in insulin rates in intensive care unit (ICU) patients. 'Glycemic variability' and 'insulin infusion rate variability' were calculated from and expressed as the

Variable volume combustor

Science.gov (United States)

Ostebee, Heath Michael; Ziminsky, Willy Steve; Johnson, Thomas Edward; Keener, Christopher Paul

2017-01-17

The present application provides a variable volume combustor for use with a gas turbine engine. The variable volume combustor may include a liner, a number of micro-mixer fuel nozzles positioned within the liner, and a linear actuator so as to maneuver the micro-mixer fuel nozzles axially along the liner.

Seasonal Variability in European Radon Measurements

Science.gov (United States)

Groves-Kirkby, C. J.; Denman, A. R.; Phillips, P. S.; Crockett, R. G. M.; Sinclair, J. M.

2009-04-01

correlations between published datasets and local geographic/geological conditions. Available data included regional SCF figures from the United Kingdom and from France, together with nationally-consolidated results from a number of other European countries. Analysis of this data shows significant variability between different countries and from region to region within those countries where regional data is available. Overall, radon-rich sedimentary geologies, particularly high porosity limestones etc., exhibit high seasonal variation, while radon-rich igneous geologies demonstrate relatively constant, albeit somewhat higher, radon concentration levels. Examples of the former can be found in the Pennines and South Downs in England, Languedoc and Brittany in France. Greatest variability is found in Switzerland, still subject to the ongoing Alpine orogeny, where the inhabited part of the country is largely overlain with recently-deposited light, porous sediments. Low-variability high-radon regions include the granite-rich Cornwall/Devon peninsular in England, and Auvergne and the Ardennes in France, all components of the Devonian-Carboniferous Hercynian belt, which extends from the Iberian peninsular through South-West Ireland and South-West England to France and Germany.

Numbers and Measuring, Learning With TOR: MINNEMAST Coordinated Mathematics - Science Series, Unit 16.

Science.gov (United States)

Vogt, Elaine E., Ed.

This volume is the sixteenth in a series of 29 coordinated MINNEMAST units in mathematics and science for kindergarten and the primary grades. Intended for use by second-grade teachers, this unit guide provides a summary and overview of the unit, a list of materials needed, and descriptions of five groups of lessons. The purposes and procedures…

Large number discrimination by mosquitofish.

Directory of Open Access Journals (Sweden)

Christian Agrillo

Full Text Available BACKGROUND: Recent studies have demonstrated that fish display rudimentary numerical abilities similar to those observed in mammals and birds. The mechanisms underlying the discrimination of small quantities (<4 were recently investigated while, to date, no study has examined the discrimination of large numerosities in fish. METHODOLOGY/PRINCIPAL FINDINGS: Subjects were trained to discriminate between two sets of small geometric figures using social reinforcement. In the first experiment mosquitofish were required to discriminate 4 from 8 objects with or without experimental control of the continuous variables that co-vary with number (area, space, density, total luminance. Results showed that fish can use the sole numerical information to compare quantities but that they preferentially use cumulative surface area as a proxy of the number when this information is available. A second experiment investigated the influence of the total number of elements to discriminate large quantities. Fish proved to be able to discriminate up to 100 vs. 200 objects, without showing any significant decrease in accuracy compared with the 4 vs. 8 discrimination. The third experiment investigated the influence of the ratio between the numerosities. Performance was found to decrease when decreasing the numerical distance. Fish were able to discriminate numbers when ratios were 1:2 or 2:3 but not when the ratio was 3:4. The performance of a sample of undergraduate students, tested non-verbally using the same sets of stimuli, largely overlapped that of fish. CONCLUSIONS/SIGNIFICANCE: Fish are able to use pure numerical information when discriminating between quantities larger than 4 units. As observed in human and non-human primates, the numerical system of fish appears to have virtually no upper limit while the numerical ratio has a clear effect on performance. These similarities further reinforce the view of a common origin of non-verbal numerical systems in all

[Relationship between family variables and conjugal adjustment].

Science.gov (United States)

Jiménez-Picón, Nerea; Lima-Rodríguez, Joaquín-Salvador; Lima-Serrano, Marta

2018-04-01

To determine whether family variables, such as type of relationship, years of marriage, existence of offspring, number of members of family, stage of family life cycle, transition between stages, perceived social support, and/or stressful life events are related to conjugal adjustment. A cross-sectional and correlational study using questionnaires. Primary care and hospital units of selected centres in the province of Seville, Spain. Consecutive stratified sampling by quotas of 369 heterosexual couples over 18years of age, who maintained a relationship, with or without children, living in Seville. A self-report questionnaire for the sociodemographic variables, and the abbreviated version of the Dyadic Adjustment Scale, Questionnaire MOS Perceived Social Support, and Social Readjustment Rating Scale, were used. Descriptive and inferential statistics were performed with correlation analysis and multivariate regression. Statistically significant associations were found between conjugal adjustment and marriage years (r=-10: Pfamily life cycle (F=2.65; Pfamily life cycle stage (mature-aged stage) on conjugal adjustment (R2=.21; F=9.9; df=356; Prelationship. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

Class Evolution Tree: A Graphical Tool to Support Decisions on the Number of Classes in Exploratory Categorical Latent Variable Modeling for Rehabilitation Research

Science.gov (United States)

Kriston, Levente; Melchior, Hanne; Hergert, Anika; Bergelt, Corinna; Watzke, Birgit; Schulz, Holger; von Wolff, Alessa

2011-01-01

The aim of our study was to develop a graphical tool that can be used in addition to standard statistical criteria to support decisions on the number of classes in explorative categorical latent variable modeling for rehabilitation research. Data from two rehabilitation research projects were used. In the first study, a latent profile analysis was…

Investigating Factorial Invariance of Latent Variables Across Populations When Manifest Variables Are Missing Completely.

Science.gov (United States)

Widaman, Keith F; Grimm, Kevin J; Early, Dawnté R; Robins, Richard W; Conger, Rand D

2013-07-01

Difficulties arise in multiple-group evaluations of factorial invariance if particular manifest variables are missing completely in certain groups. Ad hoc analytic alternatives can be used in such situations (e.g., deleting manifest variables), but some common approaches, such as multiple imputation, are not viable. At least 3 solutions to this problem are viable: analyzing differing sets of variables across groups, using pattern mixture approaches, and a new method using random number generation. The latter solution, proposed in this article, is to generate pseudo-random normal deviates for all observations for manifest variables that are missing completely in a given sample and then to specify multiple-group models in a way that respects the random nature of these values. An empirical example is presented in detail comparing the 3 approaches. The proposed solution can enable quantitative comparisons at the latent variable level between groups using programs that require the same number of manifest variables in each group.

Retention and Curve Number Variability in a Small Agricultural Catchment: The Probabilistic Approach

Directory of Open Access Journals (Sweden)

Kazimierz Banasik

2014-04-01

Full Text Available The variability of the curve number (CN and the retention parameter (S of the Soil Conservation Service (SCS-CN method in a small agricultural, lowland watershed (23.4 km2 to the gauging station in central Poland has been assessed using the probabilistic approach: distribution fitting and confidence intervals (CIs. Empirical CNs and Ss were computed directly from recorded rainfall depths and direct runoff volumes. Two measures of the goodness of fit were used as selection criteria in the identification of the parent distribution function. The measures specified the generalized extreme value (GEV, normal and general logistic (GLO distributions for 100-CN and GLO, lognormal and GEV distributions for S. The characteristics estimated from theoretical distribution (median, quantiles were compared to the tabulated CN and to the antecedent runoff conditions of Hawkins and Hjelmfelt. The distribution fitting for the whole sample revealed a good agreement between the tabulated CN and the median and between the antecedent runoff conditions (ARCs of Hawkins and Hjelmfelt, which certified a good calibration of the model. However, the division of the CN sample due to heavy and moderate rainfall depths revealed a serious inconsistency between the parameters mentioned. This analysis proves that the application of the SCS-CN method should rely on deep insight into the probabilistic properties of CN and S.

Multi-locus variable number tandem repeat analysis of 7th pandemic Vibrio cholerae

Directory of Open Access Journals (Sweden)

Lam Connie

2012-05-01

Full Text Available Abstract Background Seven pandemics of cholera have been recorded since 1817, with the current and ongoing pandemic affecting almost every continent. Cholera remains endemic in developing countries and is still a significant public health issue. In this study we use multilocus variable number of tandem repeats (VNTRs analysis (MLVA to discriminate between isolates of the 7th pandemic clone of Vibrio cholerae. Results MLVA of six VNTRs selected from previously published data distinguished 66 V. cholerae isolates collected between 1961–1999 into 60 unique MLVA profiles. Only 4 MLVA profiles consisted of more than 2 isolates. The discriminatory power was 0.995. Phylogenetic analysis showed that, except for the closely related profiles, the relationships derived from MLVA profiles were in conflict with that inferred from Single Nucleotide Polymorphism (SNP typing. The six SNP groups share consensus VNTR patterns and two SNP groups contained isolates which differed by only one VNTR locus. Conclusions MLVA is highly discriminatory in differentiating 7th pandemic V. cholerae isolates and MLVA data was most useful in resolving the genetic relationships among isolates within groups previously defined by SNPs. Thus MLVA is best used in conjunction with SNP typing in order to best determine the evolutionary relationships among the 7th pandemic V. cholerae isolates and for longer term epidemiological typing.

Soil Carbon Variability and Change Detection in the Forest Inventory Analysis Database of the United States

Science.gov (United States)

Wu, A. M.; Nater, E. A.; Dalzell, B. J.; Perry, C. H.

2014-12-01

The USDA Forest Service's Forest Inventory Analysis (FIA) program is a national effort assessing current forest resources to ensure sustainable management practices, to assist planning activities, and to report critical status and trends. For example, estimates of carbon stocks and stock change in FIA are reported as the official United States submission to the United Nations Framework Convention on Climate Change. While the main effort in FIA has been focused on aboveground biomass, soil is a critical component of this system. FIA sampled forest soils in the early 2000s and has remeasurement now underway. However, soil sampling is repeated on a 10-year interval (or longer), and it is uncertain what magnitude of changes in soil organic carbon (SOC) may be detectable with the current sampling protocol. We aim to identify the sensitivity and variability of SOC in the FIA database, and to determine the amount of SOC change that can be detected with the current sampling scheme. For this analysis, we attempt to answer the following questions: 1) What is the sensitivity (power) of SOC data in the current FIA database? 2) How does the minimum detectable change in forest SOC respond to changes in sampling intervals and/or sample point density? Soil samples in the FIA database represent 0-10 cm and 10-20 cm depth increments with a 10-year sampling interval. We are investigating the variability of SOC and its change over time for composite soil data in each FIA region (Pacific Northwest, Interior West, Northern, and Southern). To guide future sampling efforts, we are employing statistical power analysis to examine the minimum detectable change in SOC storage. We are also investigating the sensitivity of SOC storage changes under various scenarios of sample size and/or sample frequency. This research will inform the design of future FIA soil sampling schemes and improve the information available to international policy makers, university and industry partners, and the public.

Predicting Calcium Values for Gastrointestinal Bleeding Patients in Intensive Care Unit Using Clinical Variables and Fuzzy Modeling

Directory of Open Access Journals (Sweden)

G Khalili-Zadeh-Mahani

2016-07-01

Full Text Available Introduction: Reducing unnecessary laboratory tests is an essential issue in the Intensive Care Unit. One solution for this issue is to predict the value of a laboratory test to specify the necessity of ordering the tests. The aim of this paper was to propose a clinical decision support system for predicting laboratory tests values. Calcium laboratory tests of three categories of patients, including upper and lower gastrointestinal bleeding, and unspecified hemorrhage of gastrointestinal tract, have been selected as the case studies for this research. Method: In this research, the data have been collected from MIMIC-II database. For predicting calcium laboratory values, a Fuzzy Takagi-Sugeno model is used and the input variables of the model are heart rate and previous value of calcium laboratory test. Results: The results showed that the values of calcium laboratory test for the understudy patients were predictable with an acceptable accuracy. In average, the mean absolute errors of the system for the three categories of the patients are 0.27, 0.29, and 0.28, respectively. Conclusion: In this research, using fuzzy modeling and two variables of heart rate and previous calcium laboratory values, a clinical decision support system was proposed for predicting laboratory values of three categories of patients with gastrointestinal bleeding. Using these two clinical values as input variables, the obtained results were acceptable and showed the capability of the proposed system in predicting calcium laboratory values. For achieving better results, the impact of more input variables should be studied. Since, the proposed system predicts the laboratory values instead of just predicting the necessity of the laboratory tests; it was more generalized than previous studies. So, the proposed method let the specialists make the decision depending on the condition of each patient.

Interannual and Decadal Variability of Landfalling Tropical Cyclones in the Southeast Coastal States of the United States

Institute of Scientific and Technical Information of China (English)

无

2002-01-01

The interannual variability of the At lantic tropical cyclone (TC) frequency is well known. Separately,recent studies have also suggested that a much longer, multidecadal (40-60 year) trend might be emerging from the recent increase in Atlantic TC activity. However, the overall structure of the intrinsic frequencies (or temporal modes) of Atlantic TC activity is not yet known. The focus of this study is to systematically analyze the intrinsic frequencies of Atlantic TC activity using hurricane and tropical storm landfall data collected along the southeast coast (SEC) of the United States. Based on an Empirical Mode Decomposition (EMD) analysis of the frequency of landfall TCs along the SEC from 1887-1999, we have found that Atlantic TC activity has four primary, temporal modes. The interannual and multidecadal modes reported in the published literature are two such modes. After identifying all primary modes, the relative importance of each mode and its physical cause can be analyzed. For example, the most energetic mode is the interannual mode (2-7 year period). This mode is known to be associated with the 2-7 year El Nino / La Ni na cycle. The average number of annual landfalling TCs along the SEC decreased by 24% during El Nino years, but did not show significant increase during weak and moderate La Nina years. However, intense La Nina years were generally associated with more than average landfalling TCs along the SEC. The effects of El Nino and La Nina also became more significant when only hurricanes were considered. The significance of the effects of El Nino and La Nina on landfalling TCs and hurricanes in different US southeast coastal states showed significant differences.

Development of a Hierarchical Variable-Number Tandem Repeat Typing Scheme for Mycobacterium tuberculosis in China

Science.gov (United States)

Luo, Tao; Yang, Chongguang; Pang, Yu; Zhao, Yanlin; Mei, Jian; Gao, Qian

2014-01-01

Molecular typing based on variable-number tandem repeats (VNTR) analysis is a promising tool for identifying transmission of Mycobacterium tuberculosis. However, the currently proposed 15- and 24-locus VNTR sets (VNTR-15/24) only have limited resolution and contain too many loci for large-scale typing in high burden countries. To develop an optimal typing scheme in China, we evaluated the resolution and robustness of 25 VNTR loci, using population-based collections of 1362 clinical isolates from six provinces across the country. The resolution of most loci showed considerable variations among regions. By calculating the average resolution of all possible combinations of 20 robust loci, we identified an optimal locus set with a minimum of 9 loci (VNTR-9) that could achieve comparable resolution of the standard VNTR-15. The VNTR-9 had consistently high resolutions in all six regions, and it was highly concordant with VNTR-15 for defining both clustered and unique genotypes. Furthermore, VNTR-9 was phylogenetically informative for classifying lineages/sublineages of M. tuberculosis. Three hypervariable loci (HV-3), VNTR 3232, VNTR 3820 and VNTR 4120, were proved important for further differentiating unrelated clustered strains based on VNTR-9. We propose the optimized VNTR-9 as first-line method and the HV-3 as second-line method for molecular typing of M. tuberculosis in China and surrounding countries. The development of hierarchical VNTR typing methods that can achieve high resolution with a small number of loci could be suitable for molecular epidemiology study in other high burden countries. PMID:24586989

Identification of Variable-Number Tandem-Repeat (VNTR) Sequences in Legionella pneumophila and Development of an Optimized Multiple-Locus VNTR Analysis Typing Scheme▿

Science.gov (United States)

Pourcel, Christine; Visca, Paolo; Afshar, Baharak; D'Arezzo, Silvia; Vergnaud, Gilles; Fry, Norman K.

2007-01-01

The utility of a genotypic typing assay for Legionella pneumophila was investigated. A multiple-locus variable number of tandem repeats (VNTR) analysis (MLVA) scheme using PCR and agarose gel electrophoresis is proposed based on eight minisatellite markers. Panels of well-characterized strains were examined in a multicenter analysis to validate the assay and to compare its performance to that of other genotyping assays. Excellent typeability, reproducibility, stability, and epidemiological concordance were observed. The MLVA type or profile is composed of a string of allele numbers, corresponding to the number of repeats at each VNTR locus, separated by commas, in a predetermined order. A database containing information from 99 L. pneumophila serogroup 1 strains and four strains of other serogroups and their MLVA profiles, which can be queried online, is available from http://bacterial-genotyping.igmors.u-psud.fr/. PMID:17251393

Key Spatial Factors Influencing the Perceived Privacy in Nursing Units: An Exploration Study With Eight Nursing Units in Hong Kong.

Science.gov (United States)

Lu, Yi; Cai, Hui; Bosch, Sheila J

2017-07-01

This study examined how the spatial characteristics of patient beds, which are influenced by patient room design and nursing unit configuration, affect patients' perceptions about privacy. In the hospital setting, most patients expect a certain degree of privacy but also understand that their caregivers need appropriate access to them in order to provide high-quality care. Even veteran healthcare designers may struggle to create just the right balance between privacy and accessibility. A paper-based survey was conducted with 159 participants in Hong Kong-72 (45.3%) participants had been hospitalized and 87 (54.7%) participants had not-to document their selection of high-privacy beds, given simplified plans of eight nursing units. Two types of information, comprised of six variables, were examined for each bed. These include (1) room-level variables, specifically the number of beds per room and area per bed and (2) relational variables, including walking distance, directional change, integration, and control. The results demonstrate that when asked to identify high-privacy beds, participants selected beds in patient rooms with fewer beds per room, a larger area per bed, and a longer walking distance to the care team workstation. Interestingly, the participants having been hospitalized also chose beds with a visual connection to the care team workstation as being high in privacy. The participants with hospitalization experience may be willing to accept a bed with reduced visual privacy, perhaps out of a concern for safety.

How well do the GCMs/RCMs capture the multi-scale temporal variability of precipitation in the Southwestern United States?

Science.gov (United States)

Jiang, Peng; Gautam, Mahesh R.; Zhu, Jianting; Yu, Zhongbo

2013-02-01

SummaryMulti-scale temporal variability of precipitation has an established relationship with floods and droughts. In this paper, we present the diagnostics on the ability of 16 General Circulation Models (GCMs) from Bias Corrected and Downscaled (BCSD) World Climate Research Program's (WCRP's) Coupled Model Inter-comparison Project Phase 3 (CMIP3) projections and 10 Regional Climate Models (RCMs) that participated in the North American Regional Climate Change Assessment Program (NARCCAP) to represent multi-scale temporal variability determined from the observed station data. Four regions (Los Angeles, Las Vegas, Tucson, and Cimarron) in the Southwest United States are selected as they represent four different precipitation regions classified by clustering method. We investigate how storm properties and seasonal, inter-annual, and decadal precipitation variabilities differed between GCMs/RCMs and observed records in these regions. We find that current GCMs/RCMs tend to simulate longer storm duration and lower storm intensity compared to those from observed records. Most GCMs/RCMs fail to produce the high-intensity summer storms caused by local convective heat transport associated with the summer monsoon. Both inter-annual and decadal bands are present in the GCM/RCM-simulated precipitation time series; however, these do not line up to the patterns of large-scale ocean oscillations such as El Nino/La Nina Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO). Our results show that the studied GCMs/RCMs can capture long-term monthly mean as the examined data is bias-corrected and downscaled, but fail to simulate the multi-scale precipitation variability including flood generating extreme events, which suggests their inadequacy for studies on floods and droughts that are strongly associated with multi-scale temporal precipitation variability.

Genetic variability, heritability and genetic advance of quantitative ...

African Journals Online (AJOL)

Genetic variation has led to an increase in the quantitative traits of crops. The variability on genome is induced by mutation, which enhances the productivity. We evaluated variability on quantitative characters such as, plant height, number of branches/plant, number of leaves/plant, number of fruit clusters/plant, number of ...

The massive 3-loop operator matrix elements with two masses and the generalized variable flavor number scheme

Energy Technology Data Exchange (ETDEWEB)

Ablinger, J.; Schneider, C. [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation (RISC); Bluemlein, J.; Freitas, A. de; Schoenwald, K. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Goedicke, A. [Karlsruher Institut fuer Technologie (KIT), Karlsruhe (Germany). Inst. fuer Theoretische Teilchenphysik; Wissbrock, F. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation (RISC)

2017-12-15

We report on our latest results in the calculation of the two-mass contributions to 3-loop operator matrix elements (OMEs). These OMEs are needed to compute the corresponding contributions to the deep-inelastic scattering structure functions and to generalize the variable flavor number scheme by including both charm and bottom quarks. We present the results for the non-singlet and A{sub gq,Q} OMEs, and compare the size of their contribution relative to the single mass case. Results for the gluonic OME A{sub gg,Q} are given in the physical case, going beyond those presented in a previous publication where scalar diagrams were computed. We also discuss our recently published two-mass contribution to the pure singlet OME, and present an alternative method of calculating the corresponding diagrams.

Low density lesion in solid mass on CT: Pathologic change and housfield number

International Nuclear Information System (INIS)

Han, Tae Il; Lim, Joo Won; Ryu, Kyung Nam; Ko, Young Tae; Song, Mi Jin; Lee, Dong Ho; Lee, Ju Hie

1994-01-01

We retrospectively reviewed the pathologic changes and housfield unit of the low density lesion in solid mass on CT. Pathologically proved solid mass was evaluated in regard to the shape and margin of the low density in the mass on the CT scans of 23 patient. The CT number of the low density lesion was correlated with the pathologic changes. Pathologic changes of the low density lesions were; necrosis (n=17), hemorrhage (n=13), cyst (n=4), myxoid degeneration (n=2), hyaline degeneration (n=1), fibrosis (n=1), and mixed cellularity (n=1). In 14 cases, more than 2 pathologic changes were seen. In 11 cases, necrosis was associated with hemorrhage. The CT number ranged from 11.5 to 44.9 Housfield unit(HU) (mean, 25.2 HU). The average CT number was 26.9 HU in hemorrhage and necrosis, 17.2 HU in cystic change, 20.9 HU in myxoid degeneration, 35.7 HU in hyaline de generation, 22.3 HU in fibrosis, and 21.4 HU in mixed cellularity. The hemorrhage and necrosis in 17 cases showed irregular margin, amorphous shape, and showed centrifugal distribution. The cystic change in 4 cases showed well defined margin, round shape, and peripheral location in solid mass. The low density lesions in solid mass on CT represented variable pathologic changes; necrosis, hemorrhage, cyst, myxoid degeneration, hyaline degeneration, fibrosis, and mixed cellularity. Pathologic changes would not be differentiated on the basis of CT number

UNIT TRUST FUND'S INITIAL SERVICE CHARGE AND ITS DETERMINANTS

Directory of Open Access Journals (Sweden)

Nur Adiana Hiau Abdullah

2006-01-01

Full Text Available This paper examines the variables that might explain the initial service charge (ISC imposed on unit-holders of Malaysian unit trust funds in the year 1999. By using 39 openend unit trust funds, customer service and board structure variables are found to have asignificant effect in explaining the variations of ISC. Financial performance variables do not seem to have any influence on the level of ISC charged to the unit-holders. Our results also showed that funds which charged higher ISC do not necessarily provide higher returns to investors. Furthermore, there are unit trust funds that are having an initial service charge beyond the maximum 10% level required by the Securities Commissions or did not fulfil the independent directors requirement.

GIS Based Distributed Runoff Predictions in Variable Source Area Watersheds Employing the SCS-Curve Number

Science.gov (United States)

Steenhuis, T. S.; Mendoza, G.; Lyon, S. W.; Gerard Marchant, P.; Walter, M. T.; Schneiderman, E.

2003-04-01

Because the traditional Soil Conservation Service Curve Number (SCS-CN) approach continues to be ubiquitously used in GIS-BASED water quality models, new application methods are needed that are consistent with variable source area (VSA) hydrological processes in the landscape. We developed within an integrated GIS modeling environment a distributed approach for applying the traditional SCS-CN equation to watersheds where VSA hydrology is a dominant process. Spatial representation of hydrologic processes is important for watershed planning because restricting potentially polluting activities from runoff source areas is fundamental to controlling non-point source pollution. The methodology presented here uses the traditional SCS-CN method to predict runoff volume and spatial extent of saturated areas and uses a topographic index to distribute runoff source areas through watersheds. The resulting distributed CN-VSA method was incorporated in an existing GWLF water quality model and applied to sub-watersheds of the Delaware basin in the Catskill Mountains region of New York State. We found that the distributed CN-VSA approach provided a physically-based method that gives realistic results for watersheds with VSA hydrology.

Stellar Variability at the Main-sequence Turnoff of the Intermediate-age LMC Cluster NGC 1846

Science.gov (United States)

Salinas, R.; Pajkos, M. A.; Vivas, A. K.; Strader, J.; Contreras Ramos, R.

2018-04-01

Intermediate-age (IA) star clusters in the Large Magellanic Cloud (LMC) present extended main-sequence turn-offs (MSTO) that have been attributed to either multiple stellar populations or an effect of stellar rotation. Recently it has been proposed that these extended main sequences can also be produced by ill-characterized stellar variability. Here we present Gemini-S/Gemini Multi-Object Spectrometer (GMOS) time series observations of the IA cluster NGC 1846. Using differential image analysis, we identified 73 new variable stars, with 55 of those being of the Delta Scuti type, that is, pulsating variables close the MSTO for the cluster age. Considering completeness and background contamination effects, we estimate the number of δ Sct belonging to the cluster between 40 and 60 members, although this number is based on the detection of a single δ Sct within the cluster half-light radius. This amount of variable stars at the MSTO level will not produce significant broadening of the MSTO, albeit higher-resolution imaging will be needed to rule out variable stars as a major contributor to the extended MSTO phenomenon. Though modest, this amount of δ Sct makes NGC 1846 the star cluster with the highest number of these variables ever discovered. Lastly, our results present a cautionary tale about the adequacy of shallow variability surveys in the LMC (like OGLE) to derive properties of its δ Sct population. Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the National Research Council (Canada), CONICYT (Chile), Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina), and Ministério da Ciência, Tecnologia e Inovação (Brazil).

Sensitivity analysis on uncertainty variables affecting the NPP's LUEC with probabilistic approach

International Nuclear Information System (INIS)

Nuryanti; Akhmad Hidayatno; Erlinda Muslim

2013-01-01

One thing that is quite crucial to be reviewed prior to any investment decision on the nuclear power plant (NPP) project is the calculation of project economic, including calculation of Levelized Unit Electricity Cost (LUEC). Infrastructure projects such as NPP’s project are vulnerable to a number of uncertainty variables. Information on the uncertainty variables which makes LUEC’s value quite sensitive due to the changes of them is necessary in order the cost overrun can be avoided. Therefore this study aimed to do the sensitivity analysis on variables that affect LUEC with probabilistic approaches. This analysis was done by using Monte Carlo technique that simulate the relationship between the uncertainty variables and visible impact on LUEC. The sensitivity analysis result shows the significant changes on LUEC value of AP1000 and OPR due to the sensitivity of investment cost and capacity factors. While LUEC changes due to sensitivity of U 3 O 8 ’s price looks not quite significant. (author)

Variable screening and ranking using sampling-based sensitivity measures

International Nuclear Information System (INIS)

Wu, Y-T.; Mohanty, Sitakanta

2006-01-01

This paper presents a methodology for screening insignificant random variables and ranking significant important random variables using sensitivity measures including two cumulative distribution function (CDF)-based and two mean-response based measures. The methodology features (1) using random samples to compute sensitivities and (2) using acceptance limits, derived from the test-of-hypothesis, to classify significant and insignificant random variables. Because no approximation is needed in either the form of the performance functions or the type of continuous distribution functions representing input variables, the sampling-based approach can handle highly nonlinear functions with non-normal variables. The main characteristics and effectiveness of the sampling-based sensitivity measures are investigated using both simple and complex examples. Because the number of samples needed does not depend on the number of variables, the methodology appears to be particularly suitable for problems with large, complex models that have large numbers of random variables but relatively few numbers of significant random variables

Combination of Single Nucleotide Polymorphism and Variable-Number Tandem Repeats for Genotyping a Homogenous Population of Mycobacterium tuberculosis Beijing Strains in China

OpenAIRE

Luo, Tao; Yang, Chongguang; Gagneux, Sebastien; Gicquel, Brigitte; Mei, Jian; Gao, Qian

2012-01-01

The standard 15- and 24-locus variable-number tandem repeat (VNTR) genotyping methods have demonstrated adequate discriminatory power and a small homoplasy effect for tracing tuberculosis (TB) transmission and predicting Mycobacterium tuberculosis lineages in European and North American countries. However, its validity for the definition of transmission in homogenous M. tuberculosis populations in settings with high TB burdens has been questioned. Here, we genotyped a population-based collect...

Variable speed generators

CERN Document Server

Boldea, Ion

2005-01-01

With the deregulation of electrical energy production and distribution, says Boldea (Polytechnical Institute, Timisoara, Romania) producers are looking for ways to tailor their electricity for different markets. Variable-speed electric generators are serving that purpose, up to the 400 megavolt ampere unit size, in Japan since 1996 and Germany sinc

Análise genotípica de isolados de Mycobacterium tuberculosis de um hospital em Lisboa, Portugal

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João Perdigão

2009-09-01

Full Text Available Resumo: Portugal apresenta uma das taxas de incidência de tuberculose mais altas da União Europeia, tendo a Região de Saúde de Lisboa uma taxa de incidência muito acima da média nacional. O presente estudo analisa a transmissão, susceptibilidade aos antibacilares e características de uma população de estudo de um hospital central de Lisboa. Cento e trinta e dois isolados clínicos de Mycobacterium tuberculosis foram pre-viamente testados quanto à susceptibilidade aos antibacilares de primeira linha. A taxa de multirresistência encontrada foi de 3,0%, enquanto 13,6% dos isolados eram resistentes a um ou mais antibacilares de primeira linha. A serologia para o VIH estava disponível para 98 doentes, 26 (26,5% eram positivos. Os isolados foram genotipados por MIRU-VNTR e 53 (40,2% dos 132 isolados encontravam-se distribuídos por 17 clusters MIRU-VNTR diferentes de dois ou mais isolados. De todos os isolados analisados, 25,8% perten-ciam à família Lisboa. Concluímos que a transmissão de estirpes de Mycobacterium tuberculosis, resistentes e susceptíveis, está a ocorrer, com especial preocupação para as estirpes Lisboa.Rev Port Pneumol 2009; XV (5: 761-769 Abstract: Portugal has one of the highest tuberculosis notification rates of the European Union with Lisbon Health Region having an incidence rate well above the national average. The present study analyses the transmission, drug susceptibility and characteristics of a study population from a Central Lisbon’s Hospital. One hundred and thirty-two Mycobacterium tuberculosis clinical isolates were previously tested for drug susceptibility to first-line drugs. The multidrug (MDR resistance rate was found to be 3.0%, while 13.6% of the isolates were resistant to one or more first-line drugs. HIV serology was available for 98 patients, 26 (26.5% were positive. Genotyping was performed by MIRU-VNTR and 53 (40,2% out of the 132 isolates

Molecular characterization of Leptospira sp by multilocus variable number tandem repeat analysis (MLVA from clinical samples: a case report

Directory of Open Access Journals (Sweden)

Hélène Pailhoriès

2015-08-01

Full Text Available Leptospirosis is a zoonotic infection for which diagnosis is difficult. It has appeared as a global emerging infectious disease over recent years. Genotype determination often requires a Leptospira strain obtained by culture, which is a long and fastidious technique. A method based on multilocus variable number tandem repeat analysis (MLVA to determine the genotype of Leptospira interrogans, performed directly on blood or urine samples, is proposed. This method was applied to a fatal case of leptospirosis for which the geographical origin of infection was unknown. This technique will allow a genotype to be obtained for L. interrogans, even when cultures remain negative.

One perspective on spatial variability in geologic mapping

Science.gov (United States)

Markewich, H.W.; Cooper, S.C.

1991-01-01

This paper discusses some of the differences between geologic mapping and soil mapping, and how the resultant maps are interpreted. The role of spatial variability in geologic mapping is addressed only indirectly because in geologic mapping there have been few attempts at quantification of spatial differences. This is largely because geologic maps deal with temporal as well as spatial variability and consider time, age, and origin, as well as composition and geometry. Both soil scientists and geologists use spatial variability to delineate mappable units; however, the classification systems from which these mappable units are defined differ greatly. Mappable soil units are derived from systematic, well-defined, highly structured sets of taxonomic criteria; whereas mappable geologic units are based on a more arbitrary heirarchy of categories that integrate many features without strict values or definitions. Soil taxonomy is a sorting tool used to reduce heterogeneity between soil units. Thus at the series level, soils in any one series are relatively homogeneous because their range of properties is small and well-defined. Soil maps show the distribution of soils on the land surface. Within a map area, soils, which are often less than 2 m thick, show a direct correlation to topography and to active surface processes as well as to parent material.

Characterization of Nighttime Light Variability Over the Southeastern United States

Science.gov (United States)

Cole, Tony A.; Molthan, Andrew L.; Schultz, Lori A.

2016-01-01

City lights provide indications of human activity at night. Nighttime satellite imagery offers daily snapshots of this activity. With calibrated, science-quality imagery, long-term monitoring can also be achieved. The degree to which city lights fluctuate, however, is not well known. For the application of detecting power outages, this degree of variability is crucial for assessing reductions to city lights based on historical trends. Eight southeastern U.S. cities are analyzed to understand the relationship between emission variability and several population centers. A preliminary, example case power outage study is also discussed as a transition into future work.

cn.FARMS: a latent variable model to detect copy number variations in microarray data with a low false discovery rate.

Science.gov (United States)

Clevert, Djork-Arné; Mitterecker, Andreas; Mayr, Andreas; Klambauer, Günter; Tuefferd, Marianne; De Bondt, An; Talloen, Willem; Göhlmann, Hinrich; Hochreiter, Sepp

2011-07-01

Cost-effective oligonucleotide genotyping arrays like the Affymetrix SNP 6.0 are still the predominant technique to measure DNA copy number variations (CNVs). However, CNV detection methods for microarrays overestimate both the number and the size of CNV regions and, consequently, suffer from a high false discovery rate (FDR). A high FDR means that many CNVs are wrongly detected and therefore not associated with a disease in a clinical study, though correction for multiple testing takes them into account and thereby decreases the study's discovery power. For controlling the FDR, we propose a probabilistic latent variable model, 'cn.FARMS', which is optimized by a Bayesian maximum a posteriori approach. cn.FARMS controls the FDR through the information gain of the posterior over the prior. The prior represents the null hypothesis of copy number 2 for all samples from which the posterior can only deviate by strong and consistent signals in the data. On HapMap data, cn.FARMS clearly outperformed the two most prevalent methods with respect to sensitivity and FDR. The software cn.FARMS is publicly available as a R package at http://www.bioinf.jku.at/software/cnfarms/cnfarms.html.

Petroleomics by electrospray ionization FT-ICR mass spectrometry coupled to partial least squares with variable selection methods: prediction of the total acid number of crude oils.

Science.gov (United States)

Terra, Luciana A; Filgueiras, Paulo R; Tose, Lílian V; Romão, Wanderson; de Souza, Douglas D; de Castro, Eustáquio V R; de Oliveira, Mirela S L; Dias, Júlio C M; Poppi, Ronei J

2014-10-07

Negative-ion mode electrospray ionization, ESI(-), with Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) was coupled to a Partial Least Squares (PLS) regression and variable selection methods to estimate the total acid number (TAN) of Brazilian crude oil samples. Generally, ESI(-)-FT-ICR mass spectra present a power of resolution of ca. 500,000 and a mass accuracy less than 1 ppm, producing a data matrix containing over 5700 variables per sample. These variables correspond to heteroatom-containing species detected as deprotonated molecules, [M - H](-) ions, which are identified primarily as naphthenic acids, phenols and carbazole analog species. The TAN values for all samples ranged from 0.06 to 3.61 mg of KOH g(-1). To facilitate the spectral interpretation, three methods of variable selection were studied: variable importance in the projection (VIP), interval partial least squares (iPLS) and elimination of uninformative variables (UVE). The UVE method seems to be more appropriate for selecting important variables, reducing the dimension of the variables to 183 and producing a root mean square error of prediction of 0.32 mg of KOH g(-1). By reducing the size of the data, it was possible to relate the selected variables with their corresponding molecular formulas, thus identifying the main chemical species responsible for the TAN values.

Quantifying human disturbance in watersheds: Variable selection and performance of a GIS-based disturbance index for predicting the biological condition of perennial streams

Science.gov (United States)

Falcone, James A.; Carlisle, Daren M.; Weber, Lisa C.

2010-01-01

Characterizing the relative severity of human disturbance in watersheds is often part of stream assessments and is frequently done with the aid of Geographic Information System (GIS)-derived data. However, the choice of variables and how they are used to quantify disturbance are often subjective. In this study, we developed a number of disturbance indices by testing sets of variables, scoring methods, and weightings of 33 potential disturbance factors derived from readily available GIS data. The indices were calibrated using 770 watersheds located in the western United States for which the severity of disturbance had previously been classified from detailed local data by the United States Environmental Protection Agency (USEPA) Environmental Monitoring and Assessment Program (EMAP). The indices were calibrated by determining which variable or variable combinations and aggregation method best differentiated between least- and most-disturbed sites. Indices composed of several variables performed better than any individual variable, and best results came from a threshold method of scoring using six uncorrelated variables: housing unit density, road density, pesticide application, dam storage, land cover along a mainstem buffer, and distance to nearest canal/pipeline. The final index was validated with 192 withheld watersheds and correctly classified about two-thirds (68%) of least- and most-disturbed sites. These results provide information about the potential for using a disturbance index as a screening tool for a priori ranking of watersheds at a regional/national scale, and which landscape variables and methods of combination may be most helpful in doing so.

Longitudinal survey of Staphylococcus aureus in cystic fibrosis patients using a multiple-locus variable-number of tandem-repeats analysis method

OpenAIRE

Vergnaud Gilles; Moissenet Didier; Corvol Harriet; Fauroux Brigitte; Corbineau Gaëlle; Hormigos Katia; Vu-Thien Hoang; Pourcel Christine

2010-01-01

Abstract Background Staphylococcus aureus infection in patients with cystic fibrosis (CF) is frequent and may be due to colonization by a few pathogenic lineages. Systematic genotyping of all isolates, methicillin-susceptible S. aureus (MSSA) as well as methicillin-resistant S. aureus (MRSA) is necessary to identify such lineages and follow their evolution in patients. Multiple-locus variable-number tandem repeat analysis (MLVA/VNTR) was used to survey S. aureus clinical isolates in a French ...

DNF Tautologies with a Limited Number of Occurrences of Every Variable

Czech Academy of Sciences Publication Activity Database

Savický, Petr; Sgall, Jiří

2000-01-01

Roč. 238, 1-2 (2000), s. 495-498 ISSN 0304-3975 R&D Projects: GA ČR GA201/98/0717; GA AV ČR IAA1019602; GA ČR GA201/97/P038; GA MŠk ME 103 Institutional research plan: AV0Z1030915 Keywords : disjunctive normal form * tautology * occurences of variable Subject RIV: BA - General Mathematics Impact factor: 0.417, year: 2000

Assessment of Weight Management Practices among Adults in the United Arab Emirates

OpenAIRE

Attlee, Amita; Atmani, Nour; Stromtsov, Viktor; Ali, Fatima; Tikarly, Rim; Ryad, Sarah; Salah, Ghada; Hasan, Hayder; Obaid, Reyad

2017-01-01

With a rise in global incidence of overweight and obesity, the number of patients seeking weight management (WM) advice is likely to increase. Our aim was to explore the prevalence of WM practices and investigate association of WM goals with sociodemographic variables and practices among United Arab Emirates (UAE) adults. An exploratory, cross-sectional research was conducted on 1275 adult males and females, residing in UAE. A structured questionnaire was administered. WM goals to lose/mainta...

Computing with impure numbers - Automatic consistency checking and units conversion using computer algebra

Science.gov (United States)

Stoutemyer, D. R.

1977-01-01

The computer algebra language MACSYMA enables the programmer to include symbolic physical units in computer calculations, and features automatic detection of dimensionally-inhomogeneous formulas and conversion of inconsistent units in a dimensionally homogeneous formula. Some examples illustrate these features.

Climate drives inter-annual variability in probability of high severity fire occurrence in the western United States

Science.gov (United States)

Keyser, Alisa; Westerling, Anthony LeRoy

2017-05-01

A long history of fire suppression in the western United States has significantly changed forest structure and ecological function, leading to increasingly uncharacteristic fires in terms of size and severity. Prior analyses of fire severity in California forests showed that time since last fire and fire weather conditions predicted fire severity very well, while a larger regional analysis showed that topography and climate were important predictors of high severity fire. There has not yet been a large-scale study that incorporates topography, vegetation and fire-year climate to determine regional scale high severity fire occurrence. We developed models to predict the probability of high severity fire occurrence for the western US. We predict high severity fire occurrence with some accuracy, and identify the relative importance of predictor classes in determining the probability of high severity fire. The inclusion of both vegetation and fire-year climate predictors was critical for model skill in identifying fires with high fractional fire severity. The inclusion of fire-year climate variables allows this model to forecast inter-annual variability in areas at future risk of high severity fire, beyond what slower-changing fuel conditions alone can accomplish. This allows for more targeted land management, including resource allocation for fuels reduction treatments to decrease the risk of high severity fire.

Effect of trotting speed on kinematic variables measured by use of extremity-mounted inertial measurement units in nonlame horses performing controlled treadmill exercise.

Science.gov (United States)

Cruz, Antonio M; Vidondo, Beatriz; Ramseyer, Alessandra A; Maninchedda, Ugo E

2018-02-01

OBJECTIVE To assess effects of speed on kinematic variables measured by use of extremity-mounted inertial measurement units (IMUs) in nonlame horses performing controlled exercise on a treadmill. ANIMALS 10 nonlame horses. PROCEDURES 6 IMUs were attached at predetermined locations on 10 nonlame Franches Montagnes horses. Data were collected in triplicate during trotting at 3.33 and 3.88 m/s on a high-speed treadmill. Thirty-three selected kinematic variables were analyzed. Repeated-measures ANOVA was used to assess the effect of speed. RESULTS Significant differences between the 2 speeds were detected for most temporal (11/14) and spatial (12/19) variables. The observed spatial and temporal changes would translate into a gait for the higher speed characterized by increased stride length, protraction and retraction, flexion and extension, mediolateral movement of the tibia, and symmetry, but with similar temporal variables and a reduction in stride duration. However, even though the tibia coronal range of motion was significantly different between speeds, the high degree of variability raised concerns about whether these changes were clinically relevant. For some variables, the lower trotting speed apparently was associated with more variability than was the higher trotting speed. CONCLUSIONS AND CLINICAL RELEVANCE At a higher trotting speed, horses moved in the same manner (eg, the temporal events investigated occurred at the same relative time within the stride). However, from a spatial perspective, horses moved with greater action of the segments evaluated. The detected changes in kinematic variables indicated that trotting speed should be controlled or kept constant during gait evaluation.

Mastery Learning and the Decreasing Variability Hypothesis.

Science.gov (United States)

Livingston, Jennifer A.; Gentile, J. Ronald

1996-01-01

This report results from studies that tested two variations of Bloom's decreasing variability hypothesis using performance on successive units of achievement in four graduate classrooms that used mastery learning procedures. Data do not support the decreasing variability hypothesis; rather, they show no change over time. (SM)

Variability in donation after cardiac death protocols: a national survey.

Science.gov (United States)

Fugate, Jennifer E; Stadtler, Maria; Rabinstein, Alejandro A; Wijdicks, Eelco F M

2011-02-27

As donation after cardiac death practices expand, the number of institutional policies is increasing. We contacted organ procurement organizations throughout the United States and requested protocols in hospitals in their donor service areas. Sixty-four protocols were obtained with representation from 16 different states. The terminology and recommended practices varied substantially. The methods for death determination were not specified in 28 (44%) protocols. Most adhered to a 2- to 5-min observation time between circulatory arrest and organ procurement, but 10 (16%) provided no information. This variability reveals a need to define a uniform standard in donation after cardiac death protocols and death determination practices.

The Evolution of Strain Typing in the Mycobacterium tuberculosis Complex.

Science.gov (United States)

Merker, Matthias; Kohl, Thomas A; Niemann, Stefan; Supply, Philip

2017-01-01

Tuberculosis (TB) is a contagious disease with a complex epidemiology. Therefore, molecular typing (genotyping) of Mycobacterium tuberculosis complex (MTBC) strains is of primary importance to effectively guide outbreak investigations, define transmission dynamics and assist global epidemiological surveillance of the disease. Large-scale genotyping is also needed to get better insights into the biological diversity and the evolution of the pathogen. Thanks to its shorter turnaround and simple numerical nomenclature system, mycobacterial interspersed repetitive unit-variable-number tandem repeat (MIRU-VNTR) typing, based on 24 standardized plus 4 hypervariable loci, optionally combined with spoligotyping, has replaced IS6110 DNA fingerprinting over the last decade as a gold standard among classical strain typing methods for many applications. With the continuous progress and decreasing costs of next-generation sequencing (NGS) technologies, typing based on whole genome sequencing (WGS) is now increasingly performed for near complete exploitation of the available genetic information. However, some important challenges remain such as the lack of standardization of WGS analysis pipelines, the need of databases for sharing WGS data at a global level, and a better understanding of the relevant genomic distances for defining clusters of recent TB transmission in different epidemiological contexts. This chapter provides an overview of the evolution of genotyping methods over the last three decades, which culminated with the development of WGS-based methods. It addresses the relative advantages and limitations of these techniques, indicates current challenges and potential directions for facilitating standardization of WGS-based typing, and provides suggestions on what method to use depending on the specific research question.

Pathology and genetic findings in a rare case of Mycobacterium caprae infection in a sow.

Science.gov (United States)

Amato, Benedetta; Capucchio, Teresa Maria; Biasibetti, Elena; Mangano, Elena; Boniotti, Beatrice Maria; Pacciarini, Lodovica Maria; Migliore, Sergio; Vitale, Maria; Fiasconaro, Michele; Di Marco Lo Presti, Vincenzo

2017-06-01

Bovine tuberculosis, a reemerging zoonosis in diverse ecological scenarios, has been reported in the autochthonous Nebrodi black pig breed population used for meat production in Italy. During a routine abattoir inspection in 2013, 24 of 299 carcasses (8%) of Nebrodi black pigs presented tuberculosis-like lesions at pathologic examination. Mycobacterium bovis was isolated from 23 animals and M. caprae from a 3-year-old sow. The sow showed severe diffuse lesions involving the visceral organs, right coxofemoral joint, and mammary glands. Isolation of M. caprae from mammary glands is uncommon, with only one other case involving a sow reported so far; however, Mycobacteria infection of the mammary glands may be transmitted from lactating sows to piglets, contributing to the spread and maintenance of bovine tuberculosis in swine. Genotyping analysis showed M. caprae spoligotype SB0866 and profile 4,1,5,4,4,11,4,2,4,3,8,7 MIRU-VNTR (mycobacterial interspersed repetitive units-variable number of tandem repeats). The worldwide prevalence of this spoligotype is very low. The finding of severe, diffuse tuberculous lesions strongly suggests that Nebrodi black pigs are susceptible for Mycobacterium spp. and that they might act as a distributor for these microorganisms. Since natural ecosystems with multiple contacts among different livestock species and wild animals are very common in Mediterranean regions, current surveillance and eradication plans for bovine tuberculosis will need to be extended to other potential reservoir species in regions where extensive and traditional breeding systems are operated. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Centile estimation for a proportion response variable.

Science.gov (United States)

Hossain, Abu; Rigby, Robert; Stasinopoulos, Mikis; Enea, Marco

2016-03-15

This paper introduces two general models for computing centiles when the response variable Y can take values between 0 and 1, inclusive of 0 or 1. The models developed are more flexible alternatives to the beta inflated distribution. The first proposed model employs a flexible four parameter logit skew Student t (logitSST) distribution to model the response variable Y on the unit interval (0, 1), excluding 0 and 1. This model is then extended to the inflated logitSST distribution for Y on the unit interval, including 1. The second model developed in this paper is a generalised Tobit model for Y on the unit interval, including 1. Applying these two models to (1-Y) rather than Y enables modelling of Y on the unit interval including 0 rather than 1. An application of the new models to real data shows that they can provide superior fits. Copyright © 2015 John Wiley & Sons, Ltd.

Variable number of tandem repeat markers in the genome sequence of Mycosphaerella fijiensis, the causal agent of black leaf streak disease of banana (Musa spp).

Science.gov (United States)

Garcia, S A L; Van der Lee, T A J; Ferreira, C F; Te Lintel Hekkert, B; Zapater, M-F; Goodwin, S B; Guzmán, M; Kema, G H J; Souza, M T

2010-11-09

We searched the genome of Mycosphaerella fijiensis for molecular markers that would allow population genetics analysis of this plant pathogen. M. fijiensis, the causal agent of banana leaf streak disease, also known as black Sigatoka, is the most devastating pathogen attacking bananas (Musa spp). Recently, the entire genome sequence of M. fijiensis became available. We screened this database for VNTR markers. Forty-two primer pairs were selected for validation, based on repeat type and length and the number of repeat units. Five VNTR markers showing multiple alleles were validated with a reference set of isolates from different parts of the world and a population from a banana plantation in Costa Rica. Polymorphism information content values varied from 0.6414 to 0.7544 for the reference set and from 0.0400 and 0.7373 for the population set. Eighty percent of the polymorphism information content values were above 0.60, indicating that the markers are highly informative. These markers allowed robust scoring of agarose gels and proved to be useful for variability and population genetics studies. In conclusion, the strategy we developed to identify and validate VNTR markers is an efficient means to incorporate markers that can be used for fungicide resistance management and to develop breeding strategies to control banana black leaf streak disease. This is the first report of VNTR-minisatellites from the M. fijiensis genome sequence.

Genotypes of Mycobacterium tuberculosis in patients at risk of drug resistance in Bolivia.

Science.gov (United States)

Monteserin, Johana; Camacho, Mirtha; Barrera, Lucía; Palomino, Juan Carlos; Ritacco, Viviana; Martin, Anandi

2013-07-01

Bolivia ranks among the 10 Latin American countries with the highest rates of tuberculosis (TB) and multidrug resistant (MDR) TB. In view of this, and of the lacking information on the population structure of Mycobacterium tuberculosis in the country, we explored genotype associations with drug resistance and clustering by analyzing isolates collected in 2010 from 100 consecutive TB patients at risk of drug resistance in seven of the nine departments in which Bolivia is divided. Fourteen isolates were MDR, 29 had other drug resistance profiles, and 57 were pansusceptible. Spoligotype family distribution was: Haarlem 39.4%, LAM 26.3%, T 22.2%, S 2.0%, X 1.0%, orphan 9.1%, with very low intra-family diversity and absence of Beijing genotypes. We found 66 different MIRU-VNTR patterns; the most frequent corresponded to Multiple Locus Variable Analysis (MLVA) MtbC15 patterns 860, 372 and 873. Twelve clusters, each with identical MIRU-VNTR and spoligotypes, gathered 35 patients. We found no association of genotype with drug resistant or MDR-TB. Clustering associated with SIT 50 and the H3 subfamily to which it belongs (pBolivia. However, results should be taken cautiously because the sample is small and includes a particular subset of M. tuberculosis population. Copyright © 2013 Elsevier B.V. All rights reserved.

Variable-metric diffraction crystals for x-ray optics

International Nuclear Information System (INIS)

Smither, R.K.; Fernandez, P.B.

1992-01-01

A variable-metric (VM) crystal is one in which the spacing between the crystalline planes changes with position in the crystal. This variation can be either parallel to the crystalline planes or perpendicular to the crystalline planes of interest and can be produced by either introducing a thermal gradient in the crystal or by growing a crystal made of two or more elements and changing the relative percentages of the two elements as the crystal is grown. A series of experiments were performed in the laboratory to demonstrate the principle of the variable-metric crystal and its potential use in synchrotron beam lines. One of the most useful applications of the VM crystal is to increase the number of photons per unit bandwidth in a diffracted beam without losing any of the overall intensity. In a normal synchrotron beam line that uses a two-crystal monochromator, the bandwidth of the diffracted photon beam is determined by the vertical opening angle of the beam which is typically 0.10--0.30 mrad or 20--60 arcsec. When the VM crystal approach is applied, the bandwidth of the beam can be made as narrow as the rocking curve of the diffracting crystal, which is typically 0.005--0.050 mrad or 1--10 arcsec. Thus a very large increase of photons per unit bandwidth (or per unit energy) can be achieved through the use of VM crystals. When the VM principle is used with bent crystals, new kinds of x-ray optical elements can be generated that can focus and defocus x-ray beams much like simple lenses where the focal length of the lens can be changed to match its application. Thus both large magnifications and large demagnifications can be achieved as well as parallel beams with narrow bandwidths

The binding efficiency of RPA to telomeric G-strands folded into contiguous G-quadruplexes is independent of the number of G4 units.

Science.gov (United States)

Lancrey, Astrid; Safa, Layal; Chatain, Jean; Delagoutte, Emmanuelle; Riou, Jean-François; Alberti, Patrizia; Saintomé, Carole

2018-03-01

Replication protein A (RPA) is a single-stranded DNA binding protein involved in replication and in telomere maintenance. During telomere replication, G-quadruplexes (G4) can accumulate on the lagging strand template and need to be resolved. It has been shown that human RPA is able to unfold a single G4. Nevertheless, the G-strand of human telomeres is prone to fold into higher-order structures formed by contiguous G-quadruplexes. To understand how RPA deals with these structures, we studied its interaction with telomeric G-strands folding into an increasing number of contiguous G4s. The aim of this study was to determine whether the efficiency of binding/unfolding of hRPA to telomeric G-strands depends on the number of G4 units. Our data show that the number n of contiguous G4 units (n ≥ 2) does not affect the efficiency of hRPA to coat transiently exposed single-stranded telomeric G-strands. This feature may be essential in preventing instability due to G4 structures during telomere replication. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

Variable structure unit vector control of electric power generation ...

African Journals Online (AJOL)

A variable structure Automatic Generation Control (VSAGC) scheme is proposed in this paper for the control of a single area power system model dominated by steam powered electric generating plants. Unlike existing, VSAGC scheme where the selection of the control function is based on a trial and error procedure, the ...

[Statistical (Poisson) motor unit number estimation. Methodological aspects and normal results in the extensor digitorum brevis muscle of healthy subjects].

Science.gov (United States)

Murga Oporto, L; Menéndez-de León, C; Bauzano Poley, E; Núñez-Castaín, M J

Among the differents techniques for motor unit number estimation (MUNE) there is the statistical one (Poisson), in which the activation of motor units is carried out by electrical stimulation and the estimation performed by means of a statistical analysis based on the Poisson s distribution. The study was undertaken in order to realize an approximation to the MUNE Poisson technique showing a coprehensible view of its methodology and also to obtain normal results in the extensor digitorum brevis muscle (EDB) from a healthy population. One hundred fourteen normal volunteers with age ranging from 10 to 88 years were studied using the MUNE software contained in a Viking IV system. The normal subjects were divided into two age groups (10 59 and 60 88 years). The EDB MUNE from all them was 184 49. Both, the MUNE and the amplitude of the compound muscle action potential (CMAP) were significantly lower in the older age group (page than CMAP amplitude ( 0.5002 and 0.4142, respectively pphisiology of the motor unit. The value of MUNE correlates better with the neuromuscular aging process than CMAP amplitude does.

Auxiliary variables for the mapping of the drainage network: spatial correlation between relieve units, lithotypes and springs in Benevente River basin-ES

Directory of Open Access Journals (Sweden)

Tony Vinicius Moreira Sampaio

2014-12-01

Full Text Available Process of the drainage network mapping present methodological limitations re- sulting in inaccurate maps, restricting their use in environmental studies. Such problems demand the realization of long field surveys to verify the error and the search for auxiliary variables to optimize this works and turn possible the analysis of map accuracy. This research aims at the measurement of the correlation be- tween springs, lithotypes and relieve units, characterized by Roughness Concentration Index (RCI in River Basin Benevente-ES, focusing on the operations of map algebra and the use of spatial statistical techniques. These procedures have identified classes of RCI and lithotypes that present the highest and the lowest correlation with the spatial distribution of springs, indicating its potential use as auxiliary variables to verify the map accuracy.

Global Entrepreneurship and the United States

Science.gov (United States)

2010-09-01

Global Entrepreneurship and the United States by Zoltan J. Acs Laszlo Szerb Ruxton, MD 21204 for under contract number SBAHQ-09...SUBTITLE Global Entrepreneurship and the United States 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT...3 2.1. Assessing Entrepreneurship ..................................................................................4 2.2. Stages of Development

Exploratory Spectroscopy of Magnetic Cataclysmic Variables Candidates and Other Variable Objects

Science.gov (United States)

Oliveira, A. S.; Rodrigues, C. V.; Cieslinski, D.; Jablonski, F. J.; Silva, K. M. G.; Almeida, L. A.; Rodríguez-Ardila, A.; Palhares, M. S.

2017-04-01

The increasing number of synoptic surveys made by small robotic telescopes, such as the photometric Catalina Real-Time Transient Survey (CRTS), provides a unique opportunity to discover variable sources and improves the statistical samples of such classes of objects. Our goal is the discovery of magnetic Cataclysmic Variables (mCVs). These are rare objects that probe interesting accretion scenarios controlled by the white-dwarf magnetic field. In particular, improved statistics of mCVs would help to address open questions on their formation and evolution. We performed an optical spectroscopy survey to search for signatures of magnetic accretion in 45 variable objects selected mostly from the CRTS. In this sample, we found 32 CVs, 22 being mCV candidates, 13 of which were previously unreported as such. If the proposed classifications are confirmed, it would represent an increase of 4% in the number of known polars and 12% in the number of known IPs. A fraction of our initial sample was classified as extragalactic sources or other types of variable stars by the inspection of the identification spectra. Despite the inherent complexity in identifying a source as an mCV, variability-based selection, followed by spectroscopic snapshot observations, has proved to be an efficient strategy for their discoveries, being a relatively inexpensive approach in terms of telescope time. Based on observations obtained at the Observatório do Pico dos Dias/LNA, and at the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the Ministério da Ciência, Tecnologia, e Inovação (MCTI) da República Federativa do Brasil, the U.S. National Optical Astronomy Observatory (NOAO), the University of North Carolina at Chapel Hill (UNC), and Michigan State University (MSU).

Defense Horizons. Number 79, April 2015

Science.gov (United States)

2015-04-01

law , no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB...79, April 2015 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT...aggression. Even more issues emerged following the downing of Malaysian Airlines Flight 17 over Ukraine in July 2014, and cross-border ar- tillery renewed

Conflict resolution in two-digit number processing: evidence of an inhibitory mechanism.

Science.gov (United States)

Macizo, Pedro

2017-01-01

We investigated the mechanism involved in conflict resolution when individuals processed two-digit numbers. Participants performed a comparison task in blocks of two trials. In the first trial, between-decade two-digit numbers were used in a compatible condition where the decade and the unit of one number were larger than those of the other number (i.e., 21-73) and an incompatible condition where the decade of one number was larger but the unit was smaller than those of the other number (i.e., 61-53). In the second trial, within-decade two-digit numbers were presented in a related condition where the numbers contained the units presented previously (i.e., 41-43) and an unrelated condition with units that did not appear before (i.e., 48-49). In the first trial, participants responded more slowly in incompatible trials relative to compatible trials. In the second trial, participants were slower in the related condition relative to unrelated trials only after incompatible trials. These results suggest that participants experienced conflict in the incompatible condition of first trial and that they inhibited irrelevant units to resolve conflict.

Aerodynamic Effects of Turbulence Intensity on a Variable-Speed Power-Turbine Blade with Large Incidence and Reynolds Number Variations

Science.gov (United States)

Flegel, Ashlie Brynn; Giel, Paul W.; Welch, Gerard E.

2014-01-01

The effects of inlet turbulence intensity on the aerodynamic performance of a variable speed power turbine blade are examined over large incidence and Reynolds number ranges. Both high and low turbulence studies were conducted in the NASA Glenn Research Center Transonic Turbine Blade Cascade Facility. The purpose of the low inlet turbulence study was to examine the transitional flow effects that are anticipated at cruise Reynolds numbers. The high turbulence study extends this to LPT-relevant turbulence levels while perhaps sacrificing transitional flow effects. Downstream total pressure and exit angle data were acquired for ten incidence angles ranging from +15.8 to 51.0. For each incidence angle, data were obtained at five flow conditions with the exit Reynolds number ranging from 2.12105 to 2.12106 and at a design exit Mach number of 0.72. In order to achieve the lowest Reynolds number, the exit Mach number was reduced to 0.35 due to facility constraints. The inlet turbulence intensity, Tu, was measured using a single-wire hotwire located 0.415 axial-chord upstream of the blade row. The inlet turbulence levels ranged from 0.25 - 0.4 for the low Tu tests and 8- 15 for the high Tu study. Tu measurements were also made farther upstream so that turbulence decay rates could be calculated as needed for computational inlet boundary conditions. Downstream flow field measurements were obtained using a pneumatic five-hole pitchyaw probe located in a survey plane 7 axial chord aft of the blade trailing edge and covering three blade passages. Blade and endwall static pressures were acquired for each flow condition as well. The blade loading data show that the suction surface separation that was evident at many of the low Tu conditions has been eliminated. At the extreme positive and negative incidence angles, the data show substantial differences in the exit flow field. These differences are attributable to both the higher inlet Tu directly and to the thinner inlet endwall

The Pattern Across the Continental United States of Evapotranspiration Variability Associated with Water Availability

Science.gov (United States)

Koster, Randal D.; Salvucci, Guido D.; Rigden, Angela J.; Jung, Martin; Collatz, G. James; Schubert, Siegfried D.

2015-01-01

The spatial pattern across the continental United States of the interannual variance of warm season water-dependent evapotranspiration, a pattern of relevance to land-atmosphere feedback, cannot be measured directly. Alternative and indirect approaches to estimating the pattern, however, do exist, and given the uncertainty of each, we use several such approaches here. We first quantify the water dependent evapotranspiration variance pattern inherent in two derived evapotranspiration datasets available from the literature. We then search for the pattern in proxy geophysical variables (air temperature, stream flow, and NDVI) known to have strong ties to evapotranspiration. The variances inherent in all of the different (and mostly independent) data sources show some differences but are generally strongly consistent they all show a large variance signal down the center of the U.S., with lower variances toward the east and (for the most part) toward the west. The robustness of the pattern across the datasets suggests that it indeed represents the pattern operating in nature. Using Budykos hydroclimatic framework, we show that the pattern can largely be explained by the relative strength of water and energy controls on evapotranspiration across the continent.

Large numbers hypothesis. II - Electromagnetic radiation

Science.gov (United States)

Adams, P. J.

1983-01-01

This paper develops the theory of electromagnetic radiation in the units covariant formalism incorporating Dirac's large numbers hypothesis (LNH). A direct field-to-particle technique is used to obtain the photon propagation equation which explicitly involves the photon replication rate. This replication rate is fixed uniquely by requiring that the form of a free-photon distribution function be preserved, as required by the 2.7 K cosmic radiation. One finds that with this particular photon replication rate the units covariant formalism developed in Paper I actually predicts that the ratio of photon number to proton number in the universe varies as t to the 1/4, precisely in accord with LNH. The cosmological red-shift law is also derived and it is shown to differ considerably from the standard form of (nu)(R) - const.

Soil variability in engineering applications

Science.gov (United States)

Vessia, Giovanna

2014-05-01

Natural geomaterials, as soils and rocks, show spatial variability and heterogeneity of physical and mechanical properties. They can be measured by in field and laboratory testing. The heterogeneity concerns different values of litho-technical parameters pertaining similar lithological units placed close to each other. On the contrary, the variability is inherent to the formation and evolution processes experienced by each geological units (homogeneous geomaterials on average) and captured as a spatial structure of fluctuation of physical property values about their mean trend, e.g. the unit weight, the hydraulic permeability, the friction angle, the cohesion, among others. The preceding spatial variations shall be managed by engineering models to accomplish reliable designing of structures and infrastructures. Materon (1962) introduced the Geostatistics as the most comprehensive tool to manage spatial correlation of parameter measures used in a wide range of earth science applications. In the field of the engineering geology, Vanmarcke (1977) developed the first pioneering attempts to describe and manage the inherent variability in geomaterials although Terzaghi (1943) already highlighted that spatial fluctuations of physical and mechanical parameters used in geotechnical designing cannot be neglected. A few years later, Mandelbrot (1983) and Turcotte (1986) interpreted the internal arrangement of geomaterial according to Fractal Theory. In the same years, Vanmarcke (1983) proposed the Random Field Theory providing mathematical tools to deal with inherent variability of each geological units or stratigraphic succession that can be resembled as one material. In this approach, measurement fluctuations of physical parameters are interpreted through the spatial variability structure consisting in the correlation function and the scale of fluctuation. Fenton and Griffiths (1992) combined random field simulation with the finite element method to produce the Random

Fluctuations in the large-scale atmospheric circulation and ocean conditions associated with the dominant modes of wintertime precipitation variability for the contiguous United States

International Nuclear Information System (INIS)

Mitchell, T.P.; Blier, W.

1994-01-01

The historical Climatic Division record of monthly- and seasonal-mean wintertime precipitation totals are analyzed to document the dominant patterns of precipitation variability for the contiguous United States. The analysis technique employed is the Rotated Principal Component analysis. Time series for the leading patterns are related to global sea-surface temperatures (SSTs), and to gridded surface and upper-air analyses for the Northern Hemisphere

Simulation of motor unit recruitment and microvascular unit perfusion: spatial considerations.

Science.gov (United States)

Fuglevand, A J; Segal, S S

1997-10-01

Muscle fiber activity is the principal stimulus for increasing capillary perfusion during exercise. The control elements of perfusion, i.e., microvascular units (MVUs), supply clusters of muscle fibers, whereas the control elements of contraction, i.e., motor units, are composed of fibers widely scattered throughout muscle. The purpose of this study was to examine how the discordant spatial domains of MVUs and motor units could influence the proportion of open capillaries (designated as perfusion) throughout a muscle cross section. A computer model simulated the locations of perfused MVUs in response to the activation of up to 100 motor units in a muscle with 40,000 fibers and a cross-sectional area of 100 mm2. The simulation increased contraction intensity by progressive recruitment of motor units. For each step of motor unit recruitment, the percentage of active fibers and the number of perfused MVUs were determined for several conditions: 1) motor unit fibers widely dispersed and motor unit territories randomly located (which approximates healthy human muscle), 2) regionalized motor unit territories, 3) reversed recruitment order of motor units, 4) densely clustered motor unit fibers, and 5) increased size but decreased number of motor units. The simulations indicated that the widespread dispersion of motor unit fibers facilitates complete capillary (MVU) perfusion of muscle at low levels of activity. The efficacy by which muscle fiber activity induced perfusion was reduced 7- to 14-fold under conditions that decreased the dispersion of active fibers, increased the size of motor units, or reversed the sequence of motor unit recruitment. Such conditions are similar to those that arise in neuromuscular disorders, with aging, or during electrical stimulation of muscle, respectively.

Assessing the adequacy of water storage infrastructure capacity under hydroclimatic variability and water demands in the United States

Science.gov (United States)

Ho, M. W.; Devineni, N.; Cook, E. R.; Lall, U.

2017-12-01

As populations and associated economic activity in the US evolve, regional demands for water likewise change. For regions dependent on surface water, dams and reservoirs are critical to storing and managing releases of water and regulating the temporal and spatial availability of water in order to meet these demands. Storage capacities typically range from seasonal storage in the east to multi-annual and decadal-scale storage in the drier west. However, most dams in the US were designed with limited knowledge regarding the range, frequency, and persistence of hydroclimatic extremes. Demands for water supplied by these dams have likewise changed. Furthermore, many dams in the US are now reaching or have already exceeded their economic design life. The converging issues of aging dams, improved knowledge of hydroclimatic variability, and evolving demands for dam services result in a pressing need to evaluate existing reservoir capacities with respect to contemporary water demands, long term hydroclimatic variability, and service reliability into the future. Such an effort is possible given the recent development of two datasets that respectively address hydroclimatic variability in the conterminous United States over the past 555 years and human water demand related water stress over the same region. The first data set is a paleoclimate reconstruction of streamflow variability across the CONUS region based on a tree-ring informed reconstruction of the Palmer Drought Severity Index. This streamflow reconstruction suggested that wet spells with shorter drier spells were a key feature of 20th century streamflow compared with the preceding 450 years. The second data set in an annual cumulative drought index that is a measure of water balance based on water supplied through precipitation and water demands based on evaporative demands, agricultural, urban, and industrial demands. This index identified urban and regional hotspots that were particularly dependent on water

Simulation-based evaluation of the performance of the F test in a linear multilevel model setting with sparseness at the level of the primary unit.

Science.gov (United States)

Bruyndonckx, Robin; Aerts, Marc; Hens, Niel

2016-09-01

In a linear multilevel model, significance of all fixed effects can be determined using F tests under maximum likelihood (ML) or restricted maximum likelihood (REML). In this paper, we demonstrate that in the presence of primary unit sparseness, the performance of the F test under both REML and ML is rather poor. Using simulations based on the structure of a data example on ceftriaxone consumption in hospitalized children, we studied variability, type I error rate and power in scenarios with a varying number of secondary units within the primary units. In general, the variability in the estimates for the effect of the primary unit decreased as the number of secondary units increased. In the presence of singletons (i.e., only one secondary unit within a primary unit), REML consistently outperformed ML, although even under REML the performance of the F test was found inadequate. When modeling the primary unit as a random effect, the power was lower while the type I error rate was unstable. The options of dropping, regrouping, or splitting the singletons could solve either the problem of a high type I error rate or a low power, while worsening the other. The permutation test appeared to be a valid alternative as it outperformed the F test, especially under REML. We conclude that in the presence of singletons, one should be careful in using the F test to determine the significance of the fixed effects, and propose the permutation test (under REML) as an alternative. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Concurrent variable-interval variable-ratio schedules in a dynamic choice environment.

Science.gov (United States)

Bell, Matthew C; Baum, William M

2017-11-01

Most studies of operant choice have focused on presenting subjects with a fixed pair of schedules across many experimental sessions. Using these methods, studies of concurrent variable- interval variable-ratio schedules helped to evaluate theories of choice. More recently, a growing literature has focused on dynamic choice behavior. Those dynamic choice studies have analyzed behavior on a number of different time scales using concurrent variable-interval schedules. Following the dynamic choice approach, the present experiment examined performance on concurrent variable-interval variable-ratio schedules in a rapidly changing environment. Our objectives were to compare performance on concurrent variable-interval variable-ratio schedules with extant data on concurrent variable-interval variable-interval schedules using a dynamic choice procedure and to extend earlier work on concurrent variable-interval variable-ratio schedules. We analyzed performances at different time scales, finding strong similarities between concurrent variable-interval variable-interval and concurrent variable-interval variable- ratio performance within dynamic choice procedures. Time-based measures revealed almost identical performance in the two procedures compared with response-based measures, supporting the view that choice is best understood as time allocation. Performance at the smaller time scale of visits accorded with the tendency seen in earlier research toward developing a pattern of strong preference for and long visits to the richer alternative paired with brief "samples" at the leaner alternative ("fix and sample"). © 2017 Society for the Experimental Analysis of Behavior.

Assessment of Motor Units in Neuromuscular Disease.

Science.gov (United States)

Henderson, Robert D; McCombe, Pamela A

2017-01-01

The motor unit comprises the anterior horn cell, its axon, and the muscle fibers that it innervates. Although the true number of motor units is unknown, the number of motor units appears to vary greatly between different muscles and between different individuals. Assessment of the number and function of motor units is needed in diseases of the anterior horn cell and other motor nerve disorders. Amyotrophic lateral sclerosis is the most important disease of anterior horn cells. The need for an effective biomarker for assessing disease progression and for use in clinical trials in amyotrophic lateral sclerosis has stimulated the study of methods to measure the number of motor units. Since 1970 a number of different methods, including the incremental, F-wave, multipoint, and statistical methods, have been developed but none has achieved widespread applicability. Two methods (MUNIX and the multipoint incremental method) are in current use across multiple centres and are discussed in detail in this review, together with other recently published methods. Imaging with magnetic resonance and ultrasound is increasingly being applied to this area. Motor unit number estimates have also been applied to other neuromuscular diseases such as spinal muscular atrophy, compression neuropathies, and prior poliomyelitis. The need for an objective measure for the assessment of motor units remains tantalizingly close but unfulfilled in 2016.

Development of a 14-digit Hydrologic Unit Code Numbering System for South Carolina

Science.gov (United States)

Bower, David E.; Lowry, Claude; Lowery, Mark A.; Hurley, Noel M.

1999-01-01

A Hydrologic Unit Map showing the cataloging units, watersheds, and subwatersheds of South Carolina has been developed by the U.S. Geological Survey in cooperation with the South Carolina Department of Health and Environmental Control, funded through a U.S. Environmental Protection Agency 319 Grant, and the U.S. Department of Agriculture, Natural Resources Conservation Service. These delineations represent 8-, 11-, and 14-digit Hydrologic Unit Codes, respectively. This map presents information on drainage, hydrography, and hydrologic boundaries of the water-resources regions, subregions, accounting units, cataloging units, watersheds, and subwatersheds. The source maps for the basin delineations are 1:24,000-scale 7.5-minute series topographic maps and the base maps are from 1:100,000-scale Digital Line Graphs; however, the data are published at a scale of 1:500,000. In addition, an electronic version of the data is provided on a compact disc.Of the 1,022 subwatersheds delineated for this project, 1,004 range in size from 3,000 to 40,000 acres (4.69 to 62.5 square miles). Seventeen subwatersheds are smaller than 3,000 acres and one subwatershed, located on St. Helena Island, is larger than 40,000 acres.This map and its associated codes provide a standardized base for use by water-resource managers and planners in locating, storing, retrieving, and exchanging hydrologic data. In addition, the map can be used for cataloging water-data acquisition activities, geographically organizing hydrologic data, and planning and describing water-use and related land-use activities.

Variable speed drives boost air handler benefits

Energy Technology Data Exchange (ETDEWEB)

Twenty-four separate roof-top air handlers, controlled by variable speed ac motor drives, provide comfort and ventilation for employees at a 500,000 sq. ft. sportswear distribution center in southern Virginia. They were chosen over optional packaged HVAC units because of their flexibility, efficiency, and short payback advantages. The operation of the units is described.

Improving actuation efficiency through variable recruitment hydraulic McKibben muscles: modeling, orderly recruitment control, and experiments.

Science.gov (United States)

Meller, Michael; Chipka, Jordan; Volkov, Alexander; Bryant, Matthew; Garcia, Ephrahim

2016-11-03

Hydraulic control systems have become increasingly popular as the means of actuation for human-scale legged robots and assistive devices. One of the biggest limitations to these systems is their run time untethered from a power source. One way to increase endurance is by improving actuation efficiency. We investigate reducing servovalve throttling losses by using a selective recruitment artificial muscle bundle comprised of three motor units. Each motor unit is made up of a pair of hydraulic McKibben muscles connected to one servovalve. The pressure and recruitment state of the artificial muscle bundle can be adjusted to match the load in an efficient manner, much like the firing rate and total number of recruited motor units is adjusted in skeletal muscle. A volume-based effective initial braid angle is used in the model of each recruitment level. This semi-empirical model is utilized to predict the efficiency gains of the proposed variable recruitment actuation scheme versus a throttling-only approach. A real-time orderly recruitment controller with pressure-based thresholds is developed. This controller is used to experimentally validate the model-predicted efficiency gains of recruitment on a robot arm. The results show that utilizing variable recruitment allows for much higher efficiencies over a broader operating envelope.

Foundations of analysis over surreal number fields

CERN Document Server

Alling, NL

1987-01-01

In this volume, a tower of surreal number fields is defined, each being a real-closed field having a canonical formal power series structure and many other higher order properties. Formal versions of such theorems as the Implicit Function Theorem hold over such fields. The Main Theorem states that every formal power series in a finite number of variables over a surreal field has a positive radius of hyper-convergence within which it may be evaluated. Analytic functions of several surreal and surcomplex variables can then be defined and studied. Some first results in the one variable case are derived. A primer on Conway''s field of surreal numbers is also given. Throughout the manuscript, great efforts have been made to make the volume fairly self-contained. Much exposition is given. Many references are cited. While experts may want to turn quickly to new results, students should be able to find the explanation of many elementary points of interest. On the other hand, many new results are given, and much mathe...

Statistics of an ideal homogeneous Bose gas with a fixed number of particles

International Nuclear Information System (INIS)

Alekseev, Vladimir A

2001-01-01

The distribution function w 0 (n 0 ) of the number n 0 of particles is found for the condensate of an ideal gas of free bosons with a fixed total number N of particles. It is shown that above the critical temperature (T > T c ) this function has the usual form w 0 (n 0 ) = (1 - e μ )e μn 0 , where μ is the chemical potential in temperature units. In a narrow vicinity of the critical temperature |T/T c - 1| ≤ N -1/3 , this distribution changes and at T c acquires the form of a resonance. The width of the resonance depends on the shape of the volume occupied by the gas and it has exponential (but not the Gaussian) wings. As the temperature is lowered, the resonance maximum shifts to larger values of n 0 and its width tends to zero, which corresponds to the suppression of fluctuations. For N → ∞, this change occurs abruptly. The distribution function of the number of particles in excited states for the systems with a fixed and a variable number of particles (when only a mean number of particles is fixed) prove to be identical and have the usual form. (physical basis of quantum electronics)

PENGARUH UPAH, MODAL, JUMLAH UNIT USAHA, JUMLAH PRODUKSI TERHADAP PENYERAPAN TENAGA KERJA

Directory of Open Access Journals (Sweden)

Meiditya Yudi Prabaningtyas

2017-06-01

Full Text Available Tujuan dari penelitian ini adalah untuk mengetahui adanya pengaruh upah, modal, jumlah unit usaha, jumlah produksi terhadap penyerapan tenaga kerja, serta menguji peran mediasi jumlah produksi pada variabel upah, modal, jumlah unit usaha terhadap penyerapan tenaga kerja industri kecil. Populasi dalam penelitian ini adalah sentra industri kecil makanan tahu bakso yaitu sebanyak 35 unit usaha.Metodepengumpulan data yang digunakan melalui observasi dan wawancara terstruktur, metodeanalisis menggunakan statistik deskriptif dan analisis jalur (path analysis dengan menggunakan bantuan SPSS for Windowsversi 16. Hasil penelitian ini menunjukan secara parsial upah, modal, jumlah unit usaha berpengaruh positif dan signifikan terhadap jumlah produksi. Secara parsial, upah, modal, jumlah unit usaha, jumlah produksi berpengaruh positif dan signifikan terhadap penyerapan tenaga kerja. Jumlah produksi dalam penelitian ini bukan variabel yang memediasi pengaruh upah, modal, dan jumlah unit usaha terhadap penyerapan tenaga kerja yang ditunjukan dengan nilai koefisien jalur tidak langsung < nilai koefisien pengaruh langsung.  The purpose of this study was to investigate the influence of wages, capital, number of business units, the amount of production on employment, as well as test the mediating role between the variable production quantities wages, capital, number of business units to small industrial employment. The population of this research is small food industry of Tahu Bakso that is 35 business units. The method of data collection used is through observation and structural interview. The method of analysis uses descriptive statistic and path analysis using SPSS for window version 16. The results of this research shows partial the wage, capital, total of business units are positive significant to the total production. Partially wage, capital, total of business units, total production are positive significant effect on employment. Total production in this

An evaluation of FIA's stand age variable

Science.gov (United States)

John D. Shaw

2015-01-01

The Forest Inventory and Analysis Database (FIADB) includes a large number of measured and computed variables. The definitions of measured variables are usually well-documented in FIA field and database manuals. Some computed variables, such as live basal area of the condition, are equally straightforward. Other computed variables, such as individual tree volume,...

Demonstrativeness of using energy rather than mass as the unit of measure for a number of problems in physics, mechanics, and geophysics

International Nuclear Information System (INIS)

Golitsyn, G S

2008-01-01

Changing from the mass - length - time to the energy - length - time system of units is suggested as a means by which a number of problems in physics, mechanics, and geophysics can be more easily and conveniently solved using similarity analysis and dimensional methods. Eight examples are presented, with the derivations of the Stefan - Boltzmann radiation law, total kinetic energy of a hurricane, cosmic ray energy spectrum, etc. (methodological notes)

Area- and depth- weighted averages of selected SSURGO variables for the conterminous United States and District of Columbia

Science.gov (United States)

Wieczorek, Michael

2014-01-01

This digital data release consists of seven data files of soil attributes for the United States and the District of Columbia. The files are derived from National Resources Conservations Service’s (NRCS) Soil Survey Geographic database (SSURGO). The data files can be linked to the raster datasets of soil mapping unit identifiers (MUKEY) available through the NRCS’s Gridded Soil Survey Geographic (gSSURGO) database (http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/survey/geo/?cid=nrcs142p2_053628). The associated files, named DRAINAGECLASS, HYDRATING, HYDGRP, HYDRICCONDITION, LAYER, TEXT, and WTDEP are area- and depth-weighted average values for selected soil characteristics from the SSURGO database for the conterminous United States and the District of Columbia. The SSURGO tables were acquired from the NRCS on March 5, 2014. The soil characteristics in the DRAINAGE table are drainage class (DRNCLASS), which identifies the natural drainage conditions of the soil and refers to the frequency and duration of wet periods. The soil characteristics in the HYDRATING table are hydric rating (HYDRATE), a yes/no field that indicates whether or not a map unit component is classified as a "hydric soil". The soil characteristics in the HYDGRP table are the percentages for each hydrologic group per MUKEY. The soil characteristics in the HYDRICCONDITION table are hydric condition (HYDCON), which describes the natural condition of the soil component. The soil characteristics in the LAYER table are available water capacity (AVG_AWC), bulk density (AVG_BD), saturated hydraulic conductivity (AVG_KSAT), vertical saturated hydraulic conductivity (AVG_KV), soil erodibility factor (AVG_KFACT), porosity (AVG_POR), field capacity (AVG_FC), the soil fraction passing a number 4 sieve (AVG_NO4), the soil fraction passing a number 10 sieve (AVG_NO10), the soil fraction passing a number 200 sieve (AVG_NO200), and organic matter (AVG_OM). The soil characteristics in the TEXT table are

The Effect of Economic Variables on Life Expectancy of Males and Females

Directory of Open Access Journals (Sweden)

Dilek TEKER

2012-09-01

Full Text Available In this study, the relationship between life expectancy of men and women in Turkey and socio-economic variables are examined. The effect of demographic and economic factors such as the ratio of health expenditures to GDP, the ratio of elderly to employable population, the number of hospital beds per thousand people, the number of doctors per thousand patients are analyzed for a period of 1975-2009. In this study, the unit root test is initialy applied to each data set and then the cointegration test results is interpreted to determine whether a meaningful relationship exists between indicators in the long-term. Finally, the effects of the underlying factors on men and women were examined by vector error correction model. These results support that each factor has a significant effect on the life expectancy of men and women in Turkey.

Weather data for simplified energy calculation methods. Volume IV. United States: WYEC data

Energy Technology Data Exchange (ETDEWEB)

Olsen, A.R.; Moreno, S.; Deringer, J.; Watson, C.R.

1984-08-01

The objective of this report is to provide a source of weather data for direct use with a number of simplified energy calculation methods available today. Complete weather data for a number of cities in the United States are provided for use in the following methods: degree hour, modified degree hour, bin, modified bin, and variable degree day. This report contains sets of weather data for 23 cities using Weather Year for Energy Calculations (WYEC) source weather data. Considerable overlap is present in cities (21) covered by both the TRY and WYEC data. The weather data at each city has been summarized in a number of ways to provide differing levels of detail necessary for alternative simplified energy calculation methods. Weather variables summarized include dry bulb and wet bulb temperature, percent relative humidity, humidity ratio, wind speed, percent possible sunshine, percent diffuse solar radiation, total solar radiation on horizontal and vertical surfaces, and solar heat gain through standard DSA glass. Monthly and annual summaries, in some cases by time of day, are available. These summaries are produced in a series of nine computer generated tables.

Zoonotic Leprosy in the Southeastern United States

Science.gov (United States)

Sharma, Rahul; Singh, Pushpendra; Loughry, W.J.; Lockhart, J. Mitchell; Inman, W. Barry; Duthie, Malcolm S.; Pena, Maria T.; Marcos, Luis A.; Scollard, David M.; Cole, Stewart T.

2015-01-01

Nine-banded armadillos (Dasypus novemcinctus) are naturally infected with Mycobacterium leprae and have been implicated in zoonotic transmission of leprosy. Early studies found this disease mainly in Texas and Louisiana, but armadillos in the southeastern United States appeared to be free of infection. We screened 645 armadillos from 8 locations in the southeastern United States not known to harbor enzootic leprosy for M. leprae DNA and antibodies. We found M. leprae–infected armadillos at each location, and 106 (16.4%) animals had serologic/PCR evidence of infection. Using single-nucleotide polymorphism variable number tandem repeat genotyping/genome sequencing, we detected M. leprae genotype 3I-2-v1 among 35 armadillos. Seven armadillos harbored a newly identified genotype (3I-2-v15). In comparison, 52 human patients from the same region were infected with 31 M. leprae types. However, 42.3% (22/52) of patients were infected with 1 of the 2 M. leprae genotype strains associated with armadillos. The geographic range and complexity of zoonotic leprosy is expanding. PMID:26583204

The Effectiveness of Korean Number Naming on Insight into Numbers in Dutch Students with Mild Intellectual Disabilities

Science.gov (United States)

Van Luit, Johannes E. H.; Van der Molen, Mariet J.

2011-01-01

Background: Children from Asian countries score higher on early years' arithmetic tests than children from Europe or the United States of America. An explanation for these differences may be the way numbers are named. A clear ten-structure like in the Korean language method leads to a better insight into numbers and arithmetic skills. This…

One-unit versus two-unit cord-blood transplantation for hematologic cancers.

Science.gov (United States)

Wagner, John E; Eapen, Mary; Carter, Shelly; Wang, Yanli; Schultz, Kirk R; Wall, Donna A; Bunin, Nancy; Delaney, Colleen; Haut, Paul; Margolis, David; Peres, Edward; Verneris, Michael R; Walters, Mark; Horowitz, Mary M; Kurtzberg, Joanne

2014-10-30

Umbilical-cord blood has been used as the source of hematopoietic stem cells in an estimated 30,000 transplants. The limited number of hematopoietic cells in a single cord-blood unit prevents its use in recipients with larger body mass and results in delayed hematopoietic recovery and higher mortality. Therefore, we hypothesized that the greater numbers of hematopoietic cells in two units of cord blood would be associated with improved outcomes after transplantation. Between December 1, 2006, and February 24, 2012, a total of 224 patients 1 to 21 years of age with hematologic cancer were randomly assigned to undergo double-unit (111 patients) or single-unit (113 patients) cord-blood transplantation after a uniform myeloablative conditioning regimen and immunoprophylaxis for graft-versus-host disease (GVHD). The primary end point was 1-year overall survival. Treatment groups were matched for age, sex, self-reported race (white vs. nonwhite), performance status, degree of donor-recipient HLA matching, and disease type and status at transplantation. The 1-year overall survival rate was 65% (95% confidence interval [CI], 56 to 74) and 73% (95% CI, 63 to 80) among recipients of double and single cord-blood units, respectively (P=0.17). Similar outcomes in the two groups were also observed with respect to the rates of disease-free survival, neutrophil recovery, transplantation-related death, relapse, infections, immunologic reconstitution, and grade II-IV acute GVHD. However, improved platelet recovery and lower incidences of grade III and IV acute and extensive chronic GVHD were observed among recipients of a single cord-blood unit. We found that among children and adolescents with hematologic cancer, survival rates were similar after single-unit and double-unit cord-blood transplantation; however, a single-unit cord-blood transplant was associated with better platelet recovery and a lower risk of GVHD. (Funded by the National Heart, Lung, and Blood Institute and the

Variability of rRNA Operon Copy Number and Growth Rate Dynamics of Bacillus Isolated from an Extremely Oligotrophic Aquatic Ecosystem

Science.gov (United States)

Valdivia-Anistro, Jorge A.; Eguiarte-Fruns, Luis E.; Delgado-Sapién, Gabriela; Márquez-Zacarías, Pedro; Gasca-Pineda, Jaime; Learned, Jennifer; Elser, James J.; Olmedo-Alvarez, Gabriela; Souza, Valeria

2016-01-01

The ribosomal RNA (rrn) operon is a key suite of genes related to the production of protein synthesis machinery and thus to bacterial growth physiology. Experimental evidence has suggested an intrinsic relationship between the number of copies of this operon and environmental resource availability, especially the availability of phosphorus (P), because bacteria that live in oligotrophic ecosystems usually have few rrn operons and a slow growth rate. The Cuatro Ciénegas Basin (CCB) is a complex aquatic ecosystem that contains an unusually high microbial diversity that is able to persist under highly oligotrophic conditions. These environmental conditions impose a variety of strong selective pressures that shape the genome dynamics of their inhabitants. The genus Bacillus is one of the most abundant cultivable bacterial groups in the CCB and usually possesses a relatively large number of rrn operon copies (6–15 copies). The main goal of this study was to analyze the variation in the number of rrn operon copies of Bacillus in the CCB and to assess their growth-related properties as well as their stoichiometric balance (N and P content). We defined 18 phylogenetic groups within the Bacilli clade and documented a range of from six to 14 copies of the rrn operon. The growth dynamic of these Bacilli was heterogeneous and did not show a direct relation to the number of operon copies. Physiologically, our results were not consistent with the Growth Rate Hypothesis, since the copies of the rrn operon were decoupled from growth rate. However, we speculate that the diversity of the growth properties of these Bacilli as well as the low P content of their cells in an ample range of rrn copy number is an adaptive response to oligotrophy of the CCB and could represent an ecological mechanism that allows these taxa to coexist. These findings increase the knowledge of the variability in the number of copies of the rrn operon in the genus Bacillus and give insights about the

Optimal number of circulating water pumps in a nuclear power plant

International Nuclear Information System (INIS)

Xia, Lin; Liu, Deyou; Zhou, Ling; Wang, Feng; Wang, Pei

2015-01-01

Highlights: • We present a novel method to optimize the number of variable speed pumps. • The economic effect of variable speed pumps number optimization is presented. • We present a novel method to optimize the number of constant speed pumps. • The proposed pumps number optimization method is more accurate than the widely used method. - Abstract: A circulating cooling system that uses variable speed pumps (VSPs) or constant-speed pumps (CSPs) as circulating water pumps (CWPs) is optimized to improve the cycle efficiency of nuclear power plants. This study focused on the optimal number of VSPs and CSPs. A novel method is proposed to optimize the number of VSPs with varying dry-bulb temperature and relative humidity, which could help decrease operation costs by $243,310 per year. This method is also used to optimize the number of CSPs and is compared with another widely used method that optimizes the number of CSPs according to the varying condenser inlet water temperature. A comparison shows that the proposed method is more accurate than the widely used method

Optimal number of circulating water pumps in a nuclear power plant

Energy Technology Data Exchange (ETDEWEB)

Xia, Lin [College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing 210098, Jiangsu (China); Liu, Deyou, E-mail: liudyhhuc@163.com [College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing 210098, Jiangsu (China); Zhou, Ling, E-mail: zlhhu@163.com [College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing 210098, Jiangsu (China); Wang, Feng [School of Hydraulic, Energy and Power Engineering, Yangzhou University, Yangzhou 225009, Jiangsu (China); Wang, Pei [College of Energy and Electrical Engineering, Hohai University, Nanjing 210098, Jiangsu (China)

2015-07-15

Highlights: • We present a novel method to optimize the number of variable speed pumps. • The economic effect of variable speed pumps number optimization is presented. • We present a novel method to optimize the number of constant speed pumps. • The proposed pumps number optimization method is more accurate than the widely used method. - Abstract: A circulating cooling system that uses variable speed pumps (VSPs) or constant-speed pumps (CSPs) as circulating water pumps (CWPs) is optimized to improve the cycle efficiency of nuclear power plants. This study focused on the optimal number of VSPs and CSPs. A novel method is proposed to optimize the number of VSPs with varying dry-bulb temperature and relative humidity, which could help decrease operation costs by $243,310 per year. This method is also used to optimize the number of CSPs and is compared with another widely used method that optimizes the number of CSPs according to the varying condenser inlet water temperature. A comparison shows that the proposed method is more accurate than the widely used method.

Clustering of Beijing genotype Mycobacterium tuberculosis isolates from the Mekong delta in Vietnam on the basis of variable number of tandem repeat versus restriction fragment length polymorphism typing.

NARCIS (Netherlands)

Huyen, M.N.; Kremer, K.; Lan, N.T.; Buu, T.N.; Cobelens, F.G.; Tiemersma, E.W.; Haas, P. de; Soolingen, D. van

2013-01-01

BACKGROUND: In comparison to restriction fragment length polymorphism (RFLP) typing, variable number of tandem repeat (VNTR) typing is easier to perform, faster and yields results in a simple, numerical format. Therefore, this technique has gained recognition as the new international gold standard

Dynamics calculation with variable mass of mountain self-propelled chassis

Directory of Open Access Journals (Sweden)

R.M. Makharoblidze

2016-12-01

Full Text Available Many technological processes in the field of agricultural production mechanization, such as a grain crop, planting root-tuber fruits, fertilizing, spraying and dusting, pressing feed materials, harvesting of various cultures, etc. are performed by the machine-tractor units with variable mass of links or processed media and materials. In recent years, are also developing the systems of automatic control, adjusting and control of technological processes and working members in agriculture production. Is studied the dynamics of transition processes of mountain self-propelled chassis with variable mass at real change disconnect or joining masses that is most often used in the function of movement (m(t = ctm(t = ct. Are derived the formulas of change of velocity of movement on displacement of unit and is defined the dependence of this velocity on the tractor and technological machine performance, with taking into account the gradual increase or removing of agricultural materials masses. According to the equation is possible to define a linear movement of machine-tractor unit. According to the obtained expressions we can define the basic operating parameters of machine-tractor unit with variable mass. The results of research would be applied at definition of characteristics of units, at development of new agricultural tractors.

Materiales. Numbers 17-20.

Science.gov (United States)

Materiales, 1995

1995-01-01

Four booklets present articles on Spanish language and culture aimed at teachers of Spanish in the United States for student use in their classes. Number 17, "Los Jovenes Espanoles" (Spanish Youth), includes articles on Spanish youth sports, music, gangs, thoughts, and t-shirt slogans: (1) "Young Spanish Athletes"; (2)…

Post-traumatic growth in parents after infants' neonatal intensive care unit hospitalisation.

Science.gov (United States)

Aftyka, Anna; Rozalska-Walaszek, Ilona; Rosa, Wojciech; Rybojad, Beata; Karakuła-Juchnowicz, Hanna

2017-03-01

To determine the incidence and severity of post-traumatic growth in a group of parents of children hospitalised in the intensive care unit in the past. A premature birth or a birth with life-threatening conditions is a traumatic event for the parents and may lead to a number of changes, some of which are positive, known as post-traumatic growth. The survey covered 106 parents of 67 infants aged 3-12 months. An original questionnaire and standardised research tools were used in the study: Impact Event Scale - Revised, Perceived Stress Scale, COPE Inventory: Positive Reinterpretation and Growth, Coping Inventory for Stressful Situations, Post-traumatic Growth Inventory and Parent and Infant Characteristic Questionnaire. Due to a stepwise backward variables selection, we found three main factors that explain post-traumatic growth: post-traumatic stress symptoms, positive reinterpretation and growth and dichotomic variable infants' survival. This model explained 29% of the post-traumatic growth variation. Similar models that were considered separately for mothers and fathers showed no significantly better properties. Post-traumatic growth was related to a lesser extent to sociodemographic variables or the stressor itself, and related to a far greater extent to psychological factors. Our study highlights the fact that post-traumatic growth in the parents of neonates hospitalised in the neonatal intensive care units remains under-evaluated. © 2016 John Wiley & Sons Ltd.

Variable Saline Concentrations for Initial Resuscitation Following Polytrauma

Science.gov (United States)

2017-02-22

AFRL-SA-WP-TR-2017-0008 Variable Saline Concentrations for Initial Resuscitation Following Polytrauma Dr. Michael Goodman...Following Polytrauma 5a. CONTRACT NUMBER FA8650-10-2-6140 5b. GRANT NUMBER FA8650-14-2-6B29 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Dr. Michael...established. We investigated the utility of standard variable saline concentrations (0.9%, 3%, 23.4%) in a murine polytrauma model of traumatic brain injury

Long-term cloud condensation nuclei number concentration, particle number size distribution and chemical composition measurements at regionally representative observatories

Science.gov (United States)

Schmale, Julia; Henning, Silvia; Decesari, Stefano; Henzing, Bas; Keskinen, Helmi; Sellegri, Karine; Ovadnevaite, Jurgita; Pöhlker, Mira L.; Brito, Joel; Bougiatioti, Aikaterini; Kristensson, Adam; Kalivitis, Nikos; Stavroulas, Iasonas; Carbone, Samara; Jefferson, Anne; Park, Minsu; Schlag, Patrick; Iwamoto, Yoko; Aalto, Pasi; Äijälä, Mikko; Bukowiecki, Nicolas; Ehn, Mikael; Frank, Göran; Fröhlich, Roman; Frumau, Arnoud; Herrmann, Erik; Herrmann, Hartmut; Holzinger, Rupert; Kos, Gerard; Kulmala, Markku; Mihalopoulos, Nikolaos; Nenes, Athanasios; O'Dowd, Colin; Petäjä, Tuukka; Picard, David; Pöhlker, Christopher; Pöschl, Ulrich; Poulain, Laurent; Prévôt, André Stephan Henry; Swietlicki, Erik; Andreae, Meinrat O.; Artaxo, Paulo; Wiedensohler, Alfred; Ogren, John; Matsuki, Atsushi; Yum, Seong Soo; Stratmann, Frank; Baltensperger, Urs; Gysel, Martin

2018-02-01

Aerosol-cloud interactions (ACI) constitute the single largest uncertainty in anthropogenic radiative forcing. To reduce the uncertainties and gain more confidence in the simulation of ACI, models need to be evaluated against observations, in particular against measurements of cloud condensation nuclei (CCN). Here we present a data set - ready to be used for model validation - of long-term observations of CCN number concentrations, particle number size distributions and chemical composition from 12 sites on 3 continents. Studied environments include coastal background, rural background, alpine sites, remote forests and an urban surrounding. Expectedly, CCN characteristics are highly variable across site categories. However, they also vary within them, most strongly in the coastal background group, where CCN number concentrations can vary by up to a factor of 30 within one season. In terms of particle activation behaviour, most continental stations exhibit very similar activation ratios (relative to particles > 20 nm) across the range of 0.1 to 1.0 % supersaturation. At the coastal sites the transition from particles being CCN inactive to becoming CCN active occurs over a wider range of the supersaturation spectrum. Several stations show strong seasonal cycles of CCN number concentrations and particle number size distributions, e.g. at Barrow (Arctic haze in spring), at the alpine stations (stronger influence of polluted boundary layer air masses in summer), the rain forest (wet and dry season) or Finokalia (wildfire influence in autumn). The rural background and urban sites exhibit relatively little variability throughout the year, while short-term variability can be high especially at the urban site. The average hygroscopicity parameter, κ, calculated from the chemical composition of submicron particles was highest at the coastal site of Mace Head (0.6) and lowest at the rain forest station ATTO (0.2-0.3). We performed closure studies based on κ-Köhler theory

7 CFR 275.6 - Management units.

Science.gov (United States)

2010-01-01

... FOOD STAMP AND FOOD DISTRIBUTION PROGRAM PERFORMANCE REPORTING SYSTEM Management Evaluation (ME... management unit; (iii) Food Stamp Program participation, including the number of persons and number of... 7 Agriculture 4 2010-01-01 2010-01-01 false Management units. 275.6 Section 275.6 Agriculture...

Aerodynamic Effects of High Turbulence Intensity on a Variable-Speed Power-Turbine Blade With Large Incidence and Reynolds Number Variations

Science.gov (United States)

Flegel, Ashlie B.; Giel, Paul W.; Welch, Gerard E.

2014-01-01

The effects of high inlet turbulence intensity on the aerodynamic performance of a variable speed power turbine blade are examined over large incidence and Reynolds number ranges. These results are compared to previous measurements made in a low turbulence environment. Both high and low turbulence studies were conducted in the NASA Glenn Research Center Transonic Turbine Blade Cascade Facility. The purpose of the low inlet turbulence study was to examine the transitional flow effects that are anticipated at cruise Reynolds numbers. The current study extends this to LPT-relevant turbulence levels while perhaps sacrificing transitional flow effects. Assessing the effects of turbulence at these large incidence and Reynolds number variations complements the existing database. Downstream total pressure and exit angle data were acquired for 10 incidence angles ranging from +15.8deg to -51.0deg. For each incidence angle, data were obtained at five flow conditions with the exit Reynolds number ranging from 2.12×10(exp 5) to 2.12×10(exp 6) and at a design exit Mach number of 0.72. In order to achieve the lowest Reynolds number, the exit Mach number was reduced to 0.35 due to facility constraints. The inlet turbulence intensity, Tu, was measured using a single-wire hotwire located 0.415 axial-chord upstream of the blade row. The inlet turbulence levels ranged from 8 to 15 percent for the current study. Tu measurements were also made farther upstream so that turbulence decay rates could be calculated as needed for computational inlet boundary conditions. Downstream flow field measurements were obtained using a pneumatic five-hole pitch/yaw probe located in a survey plane 7 percent axial chord aft of the blade trailing edge and covering three blade passages. Blade and endwall static pressures were acquired for each flow condition as well. The blade loading data show that the suction surface separation that was evident at many of the low Tu conditions has been eliminated. At

United Kingdom and United States Tourism Demand for Malaysia:A Cointegration Analysis

OpenAIRE

Habibi, Fateh; Abdul Rahim, Khalid; Chin, Lee

2008-01-01

Tourism industry has been an important contributor to the Malaysia economy. In this paper we inspect variations in the long run demand for tourism from United Kingdom and United States to Malaysia. The demand for tourism has been explained by macroeconomic variables, including income in origin countries, tourism prices in Malaysia, and travel cost between the two countries. Annual data from 1972 to 2006 are used for the analysis. Augmented Dickey-Fuller and Johansen’s maximum likelihood tests...

Clustering of Beijing genotype Mycobacterium tuberculosis isolates from the Mekong delta in Vietnam on the basis of variable number of tandem repeat versus restriction fragment length polymorphism typing

NARCIS (Netherlands)

Huyen, Mai N. T.; Kremer, Kristin; Lan, Nguyen T. N.; Buu, Tran N.; Cobelens, Frank G. J.; Tiemersma, Edine W.; de Haas, Petra; van Soolingen, Dick

2013-01-01

In comparison to restriction fragment length polymorphism (RFLP) typing, variable number of tandem repeat (VNTR) typing is easier to perform, faster and yields results in a simple, numerical format. Therefore, this technique has gained recognition as the new international gold standard in typing of

NUMBER OF SUCCESSIVE CYCLES NECESSARY TO ACHIEVE STABILITY OF SELECTED GROUND REACTION FORCE VARIABLES DURING CONTINUOUS JUMPING

Directory of Open Access Journals (Sweden)

Jasmes M.W. Brownjohn

2009-12-01

Full Text Available Because of inherent variability in all human cyclical movements, such as walking, running and jumping, data collected across a single cycle might be atypical and potentially unable to represent an individual's generalized performance. The study described here was designed to determine the number of successive cycles due to continuous, repetitive countermovement jumping which a test subject should perform in a single experimental session to achieve stability of the mean of the corresponding continuously measured ground reaction force (GRF variables. Seven vertical GRF variables (period of jumping cycle, duration of contact phase, peak force amplitude and its timing, average rate of force development, average rate of force relaxation and impulse were extracted on the cycle-by-cycle basis from vertical jumping force time histories generated by twelve participants who were jumping in response to regular electronic metronome beats in the range 2-2.8 Hz. Stability of the selected GRF variables across successive jumping cycles was examined for three jumping rates (2, 2.4 and 2.8 Hz using two statistical methods: intra-class correlation (ICC analysis and segmental averaging technique (SAT. Results of the ICC analysis indicated that an average of four successive cycles (mean 4.5 ± 2.7 for 2 Hz; 3.9 ± 2.6 for 2.4 Hz; 3.3 ± 2.7 for 2.8 Hz were necessary to achieve maximum ICC values. Except for jumping period, maximum ICC values took values from 0.592 to 0.991 and all were significantly (p < 0.05 different from zero. Results of the SAT revealed that an average of ten successive cycles (mean 10.5 ± 3.5 for 2 Hz; 9.2 ± 3.8 for 2.4 Hz; 9.0 ± 3.9 for 2.8 Hz were necessary to achieve stability of the selected parameters using criteria previously reported in the literature. Using 10 reference trials, the SAT required standard deviation criterion values of 0.49, 0.41 and 0.55 for 2 Hz, 2.4 Hz and 2.8 Hz jumping rates, respectively, in order to approximate

Software Testing Requires Variability

DEFF Research Database (Denmark)

Christensen, Henrik Bærbak

2003-01-01

Software variability is the ability of a software system or artefact to be changed, customized or configured for use in a particular context. Variability in software systems is important from a number of perspectives. Some perspectives rightly receive much attention due to their direct economic...... impact in software production. As is also apparent from the call for papers these perspectives focus on qualities such as reuse, adaptability, and maintainability....

Genetic diversity of Neisseria meningitidis serogroup C ST-4821 in China based on multiple-locus variable number tandem repeat analysis.

Directory of Open Access Journals (Sweden)

Xiaoying Shan

Full Text Available Neisseria meningitidis sequence type (ST-4821 was first reported in China in 2003, and a new hyper-virulent lineage has been designated as the ST-4821 complex. A large number of N. meningitidis ST-4821 strains have been identified in China since 2003; however, the microevolution characteristics of this complex are unclear. Different combinations of variable number of tandem repeats (VNTR loci were used in multiple-locus VNTR analysis (MLVA to analyze 118 N. meningitidis serogroup C ST-4821 strains isolated from seventeen provinces between 2003 and 2012. Additionally, MLVA with five VNTR loci was performed due to its high discriminatory power. One hundred and eighteen isolates were found to comprise 112 subtypes based on MLVA, and 16 outbreak-associated strains were clustered into one group. These data indicate a high level of diversity for N. meningitidis ST-4821 due to microevolution in the last decade. In addition, the results revealed high similarity between isolates from the same geographic origins, which is helpful when monitoring the spread of N. meningitidis serogroup C ST-4821 and will provide valuable information for the control and prevention of bacterial meningitis in China.

Corrective action investigation plan for Corrective Action Unit Number 423: Building 03-60 Underground Discharge Point, Tonopah Test Range, Nevada

International Nuclear Information System (INIS)

1997-01-01

This Corrective Action Investigation Plan (CAIP) contains the environmental sample collection objectives and the criteria for conducting site investigation activities at Corrective Action Unit (CAU) Number 423, the Building 03-60 Underground Discharge Point (UDP), which is located in Area 3 at the Tonopah Test Range (TTR). The TTR, part of the Nellis Air Force Range, is approximately 225 kilometers (140 miles) northwest of Las Vegas, Nevada. CAU Number 423 is comprised of only one Corrective Action Site (CAS) which includes the Building 03-60 UDP and an associated discharge line extending from Building 03-60 to a point approximately 73 meters (240 feet) northwest. The UDP was used between approximately 1965 and 1990 to dispose of waste fluids from the Building 03-60 automotive maintenance shop. It is likely that soils surrounding the UDP have been impacted by oil, grease, cleaning supplies and solvents as well as waste motor oil and other automotive fluids released from the UDP

Corrective action investigation plan for Corrective Action Unit Number 423: Building 03-60 Underground Discharge Point, Tonopah Test Range, Nevada

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-10-27

This Corrective Action Investigation Plan (CAIP) contains the environmental sample collection objectives and the criteria for conducting site investigation activities at Corrective Action Unit (CAU) Number 423, the Building 03-60 Underground Discharge Point (UDP), which is located in Area 3 at the Tonopah Test Range (TTR). The TTR, part of the Nellis Air Force Range, is approximately 225 kilometers (140 miles) northwest of Las Vegas, Nevada. CAU Number 423 is comprised of only one Corrective Action Site (CAS) which includes the Building 03-60 UDP and an associated discharge line extending from Building 03-60 to a point approximately 73 meters (240 feet) northwest. The UDP was used between approximately 1965 and 1990 to dispose of waste fluids from the Building 03-60 automotive maintenance shop. It is likely that soils surrounding the UDP have been impacted by oil, grease, cleaning supplies and solvents as well as waste motor oil and other automotive fluids released from the UDP.

Division in a Binary Representation for Complex Numbers

Science.gov (United States)

Blest, David C.; Jamil, Tariq

2003-01-01

Computer operations involving complex numbers, essential in such applications as Fourier transforms or image processing, are normally performed in a "divide-and-conquer" approach dealing separately with real and imaginary parts. A number of proposals have treated complex numbers as a single unit but all have foundered on the problem of the…

MASMA: a versatile multifunctional unit (gated window amplifier, analog memory, and height-to-time converter)

International Nuclear Information System (INIS)

Goursky, V.; Thenes, P.

1969-01-01

This multipurpose unit is designed to accomplish one of the following functions: - gated window amplifier, - Analog memory and - Amplitude-to-time converter. The first function is mainly devoted to improve the poor resolution of pulse-height analyzers with a small number of channels. The analog memory, a new function in the standard range of plug-in modules, is capable of performing a number of operations: 1) fixed delay, or variable delay dependent on an external parameter (application to the analog processing of non-coincident pulses), 2) de-randomiser to increase the efficiency of the pulse height analysis in a spectrometry experiment, 3) linear multiplexer to allow an analyser to serve as many spectrometry devices as memory elements that it possesses. Associated with a coding scaler, this unit, if used as a amplitude-to-time converter, constitutes a Wilkinson A.D.C with a capability of 10 bits (or more) and with a 100 MHz clock frequency. (authors) [fr

Unmeasured improvement work: the lack of routinely collected, service-related data in NHS endoscopy units in England involved in "modernisation"

Directory of Open Access Journals (Sweden)

Hutchings Hayley A

2008-01-01

Full Text Available Abstract Background The availability of routinely collected service-related endoscopy data from NHS endoscopy units has never been quantified. Methods This retrospective observational study asked 19 endoscopy units to submit copies of all in-house, service-related endoscopy data that had been routinely collected by the unit – Referral numbers, Activity, Number of patients waiting and Number of lost slots. Nine of the endoscopy units had previously participated in the Modernising Endoscopy Services (MES project during 2003 to redesign their endoscopy services. These MES sites had access to additional funding and data collection software. The other ten (Control sites had modernised independently. All data was requested in two phases and corresponded to eight specific time points between January 2003 and April 2006. Results Only eight of 19 endoscopy units submitted routinely collected, service-related data. Another site's data was collected specifically for the study. A further two units claimed to routinely collect service-related data but did not submit any to the study. The remaining eight did not collect any service-related endoscopy data routinely and liaised with their Trust for data. Of the eight sites submitting service-related data, only three were MES project sites. Of these three, the data variables collected were limited and none collected the complete set of endoscopy data variables requested. Of the other five sites, two collected all four endoscopy data types. Data for the three MES project sites went back as far as January 2003, whilst the five Control sites were only able to submit data from December 2003 onwards. Conclusion There was a lack of service-related endoscopy data routinely collected by the study sites, especially those who had participated in the MES project. Without this data, NHS endoscopy services cannot have a true understanding of their services, cannot identify problems and cannot measure the impact of any

Motor Unit Interpulse Intervals During High Force Contractions.

Science.gov (United States)

Stock, Matt S; Thompson, Brennan J

2016-01-01

We examined the means, medians, and variability for motor-unit interpulse intervals (IPIs) during voluntary, high force contractions. Eight men (mean age = 22 years) attempted to perform isometric contractions at 90% of their maximal voluntary contraction force while bipolar surface electromyographic (EMG) signals were detected from the vastus lateralis and vastus medialis muscles. Surface EMG signal decomposition was used to determine the recruitment thresholds and IPIs of motor units that demonstrated accuracy levels ≥ 96.0%. Motor units with high recruitment thresholds demonstrated longer mean IPIs, but the coefficients of variation were similar across all recruitment thresholds. Polynomial regression analyses indicated that for both muscles, the relationship between the means and standard deviations of the IPIs was linear. The majority of IPI histograms were positively skewed. Although low-threshold motor units were associated with shorter IPIs, the variability among motor units with differing recruitment thresholds was comparable.

Fixed-speed and Variable-speed Pumped Storage Dispatch Model in Power Systems with High Renewable Penetration

Science.gov (United States)

Yuan, Bo; Zong, Jin; Xu, Zhicheng

2018-06-01

According to different operating characteristics of pumped storage fixed speed unit and variable speed unit, a joint dispatching model of pumped storage unit and other types of units based on mixed integer linear optimization is constructed. The model takes into account the operating conditions, reservoir capacity, cycle type and other pumped storage unit constraints, but also consider the frequent start and stop and the stability of the operation of the unit caused by the loss. Using the Cplex solver to solve the model, the empirical example of the provincial power grid shows that the model can effectively arrange the pumping storage speed and the dispatching operation of the variable speed unit under the precondition of economic life of the unit, and give full play to the function of peak shaving and accommodating new energy. Because of its more flexible regulation characteristics of power generation and pumping conditions, the variable speed unit can better improve the operating conditions of other units in the system and promote the new energy dissipation.

Fixed-speed and Variable-speed Pumped Storage Dispatch Model in Power Systems with High Renewable Penetration

Directory of Open Access Journals (Sweden)

Yuan Bo

2018-01-01

Full Text Available According to different operating characteristics of pumped storage fixed speed unit and variable speed unit, a joint dispatching model of pumped storage unit and other types of units based on mixed integer linear optimization is constructed. The model takes into account the operating conditions, reservoir capacity, cycle type and other pumped storage unit constraints, but also consider the frequent start and stop and the stability of the operation of the unit caused by the loss. Using the Cplex solver to solve the model, the empirical example of the provincial power grid shows that the model can effectively arrange the pumping storage speed and the dispatching operation of the variable speed unit under the precondition of economic life of the unit, and give full play to the function of peak shaving and accommodating new energy. Because of its more flexible regulation characteristics of power generation and pumping conditions, the variable speed unit can better improve the operating conditions of other units in the system and promote the new energy dissipation.

Transitional boundary layer in low-Prandtl-number convection at high Rayleigh number

Science.gov (United States)

Schumacher, Joerg; Bandaru, Vinodh; Pandey, Ambrish; Scheel, Janet

2016-11-01

The boundary layer structure of the velocity and temperature fields in turbulent Rayleigh-Bénard flows in closed cylindrical cells of unit aspect ratio is revisited from a transitional and turbulent viscous boundary layer perspective. When the Rayleigh number is large enough the boundary layer dynamics at the bottom and top plates can be separated into an impact region of downwelling plumes, an ejection region of upwelling plumes and an interior region (away from side walls) that is dominated by a shear flow of varying orientation. This interior plate region is compared here to classical wall-bounded shear flows. The working fluid is liquid mercury or liquid gallium at a Prandtl number of Pr = 0 . 021 for a range of Rayleigh numbers of 3 ×105 Deutsche Forschungsgemeinschaft.

Drivers of Variability in Public-Supply Water Use Across the Contiguous United States

Science.gov (United States)

Worland, Scott C.; Steinschneider, Scott; Hornberger, George M.

2018-03-01

This study explores the relationship between municipal water use and an array of climate, economic, behavioral, and policy variables across the contiguous U.S. The relationship is explored using Bayesian-hierarchical regression models for over 2,500 counties, 18 covariates, and three higher-level grouping variables. Additionally, a second analysis is included for 83 cities where water price and water conservation policy information is available. A hierarchical model using the nine climate regions (product of National Oceanic and Atmospheric Administration) as the higher-level groups results in the best out-of-sample performance, as estimated by the Widely Available Information Criterion, compared to counties grouped by urban continuum classification or primary economic activity. The regression coefficients indicate that the controls on water use are not uniform across the nation: e.g., counties in the Northeast and Northwest climate regions are more sensitive to social variables, whereas counties in the Southwest and East North Central climate regions are more sensitive to environmental variables. For the national city-level model, it appears that arid cities with a high cost of living and relatively low water bills sell more water per customer, but as with the county-level model, the effect of each variable depends heavily on where a city is located.

The effect of normative context variability on recognition memory.

Science.gov (United States)

Steyvers, Mark; Malmberg, Kenneth J

2003-09-01

According to some theories of recognition memory (e.g., S. Dennis & M. S. Humphreys, 2001), the number of different contexts in which words appear determines how memorable individual occurrences of words will be: A word that occurs in a small number of different contexts should be better recognized than a word that appears in a larger number of different contexts. To empirically test this prediction, a normative measure is developed, referred to here as context variability, that estimates the number of different contexts in which words appear in everyday life. These findings confirm the prediction that words low in context variability are better recognized (on average) than words that are high in context variability. (c) 2003 APA, all rights reserved

Fossil fleet transition with fuel changes and large scale variable renewable integration

Energy Technology Data Exchange (ETDEWEB)

James, Revis [Electric Power Research Institute, Palo Alto, CA (United States); Hesler, Stephen [Electric Power Research Institute, Palo Alto, CA (United States); Bistline, John [Electric Power Research Institute, Palo Alto, CA (United States)

2015-03-31

Variability in demand as seen by grid-connected dispatchable generators can increase due to factors such as greater production from variable generation assets (for example, wind and solar), increased reliance on demand response or customer-driven automation, and aggregation of loads. This variability results a need for these generators to operate in a range of different modes, collectively referred to as “flexible operations.” This study is designed to inform power companies, researchers, and policymakers of the scope and trends in increasing levels of flexible operations as well as reliability challenges and impacts for dispatchable assets. Background Because there is rarely a direct monetization of the value of operational flexibility, the decision to provide such flexibility is typically dependent on unit- and region-specific decisions made by asset owners. It is very likely that much greater and more widespread flexible operations capabilities will be needed due to increased variability in demand seen by grid-connected generators, uncertainty regarding investment in new units to provide adequate operational flexibility, and the retirement of older, uncontrolled sub-critical pulverized coal units. Objective To enhance understanding of the technical challenges and operational impacts associated with dispatchable assets needed to increase operational flexibility and support variable demand. Approach The study approach consists of three elements: a literature review of relevant prior studies, analysis of detailed scenarios for evolution of the future fleet over the next 35 years, and engineering assessment of the degree and scope of technical challenges associated with transformation to the future fleet. The study approach integrated two key elements rarely brought together in a single analysis—1) long-term capacity planning, which enables modeling of unit retirements and new asset investments, and 2) unit commitment analysis, which permits examination of

DATA COLLECTION METHOD FOR PEDESTRIAN MOVEMENT VARIABLES

Directory of Open Access Journals (Sweden)

Hajime Inamura

2000-01-01

Full Text Available The need of tools for design and evaluation of pedestrian areas, subways stations, entrance hall, shopping mall, escape routes, stadium etc lead to the necessity of a pedestrian model. One approach pedestrian model is Microscopic Pedestrian Simulation Model. To be able to develop and calibrate a microscopic pedestrian simulation model, a number of variables need to be considered. As the first step of model development, some data was collected using video and the coordinate of the head path through image processing were also taken. Several numbers of variables can be gathered to describe the behavior of pedestrian from a different point of view. This paper describes how to obtain variables from video taking and simple image processing that can represent the movement of pedestrians and its variables

Comparative study of IS6110 restriction fragment length polymorphism and variable-number tandem-repeat typing of Mycobacterium tuberculosis isolates in the Netherlands, based on a 5-year nationwide survey

NARCIS (Netherlands)

de Beer, Jessica L.; van Ingen, Jakko; de Vries, Gerard; Erkens, Connie; Sebek, Maruschka; Mulder, Arnout; Sloot, Rosa; van den Brandt, Anne-Marie; Enaimi, Mimount; Kremer, Kristin; Supply, Philip; van Soolingen, Dick

2013-01-01

In order to switch from IS6110 and polymorphic GC-rich repetitive sequence (PGRS) restriction fragment length polymorphism (RFLP) to 24-locus variable-number tandem-repeat (VNTR) typing of Mycobacterium tuberculosis complex isolates in the national tuberculosis control program in The Netherlands, a

Comparative Study of IS6110 Restriction Fragment Length Polymorphism and Variable-Number Tandem-Repeat Typing of Mycobacterium tuberculosis Isolates in the Netherlands, Based on a 5-Year Nationwide Survey

NARCIS (Netherlands)

Beer, J.L. de; Ingen, J. van; Vries, G. de; Erkens, C.; Sebek, M.; Mulder, A.; Sloot, R.; Brandt, A.M. van den; Enaimi, M.; Kremer, K.; Supply, P.; Soolingen, D. van

2013-01-01

In order to switch from IS6110 and polymorphic GC-rich repetitive sequence (PGRS) restriction fragment length polymorphism (RFLP) to 24-locus variable-number tandem-repeat (VNTR) typing of Mycobacterium tuberculosis complex isolates in the national tuberculosis control program in The Netherlands, a

Complex numbers in n dimensions

CERN Document Server

Olariu, Silviu

2002-01-01

Two distinct systems of hypercomplex numbers in n dimensions are introduced in this book, for which the multiplication is associative and commutative, and which are rich enough in properties such that exponential and trigonometric forms exist and the concepts of analytic n-complex function, contour integration and residue can be defined. The first type of hypercomplex numbers, called polar hypercomplex numbers, is characterized by the presence in an even number of dimensions greater or equal to 4 of two polar axes, and by the presence in an odd number of dimensions of one polar axis. The other type of hypercomplex numbers exists as a distinct entity only when the number of dimensions n of the space is even, and since the position of a point is specified with the aid of n/2-1 planar angles, these numbers have been called planar hypercomplex numbers. The development of the concept of analytic functions of hypercomplex variables was rendered possible by the existence of an exponential form of the n-complex numbe...

Beyond the SCS curve number: A new stochastic spatial runoff approach

Science.gov (United States)

Bartlett, M. S., Jr.; Parolari, A.; McDonnell, J.; Porporato, A. M.

2015-12-01

The Soil Conservation Service curve number (SCS-CN) method is the standard approach in practice for predicting a storm event runoff response. It is popular because its low parametric complexity and ease of use. However, the SCS-CN method does not describe the spatial variability of runoff and is restricted to certain geographic regions and land use types. Here we present a general theory for extending the SCS-CN method. Our new theory accommodates different event based models derived from alternative rainfall-runoff mechanisms or distributions of watershed variables, which are the basis of different semi-distributed models such as VIC, PDM, and TOPMODEL. We introduce a parsimonious but flexible description where runoff is initiated by a pure threshold, i.e., saturation excess, that is complemented by fill and spill runoff behavior from areas of partial saturation. To facilitate event based runoff prediction, we derive simple equations for the fraction of the runoff source areas, the probability density function (PDF) describing runoff variability, and the corresponding average runoff value (a runoff curve analogous to the SCS-CN). The benefit of the theory is that it unites the SCS-CN method, VIC, PDM, and TOPMODEL as the same model type but with different assumptions for the spatial distribution of variables and the runoff mechanism. The new multiple runoff mechanism description for the SCS-CN enables runoff prediction in geographic regions and site runoff types previously misrepresented by the traditional SCS-CN method. In addition, we show that the VIC, PDM, and TOPMODEL runoff curves may be more suitable than the SCS-CN for different conditions. Lastly, we explore predictions of sediment and nutrient transport by applying the PDF describing runoff variability within our new framework.

Sensori-motor synchronisation variability decreases as the number of metrical levels in the stimulus signal increases.

Science.gov (United States)

Madison, Guy

2014-03-01

Timing performance becomes less precise for longer intervals, which makes it difficult to achieve simultaneity in synchronisation with a rhythm. The metrical structure of music, characterised by hierarchical levels of binary or ternary subdivisions of time, may function to increase precision by providing additional timing information when the subdivisions are explicit. This hypothesis was tested by comparing synchronisation performance across different numbers of metrical levels conveyed by loudness of sounds, such that the slowest level was loudest and the fastest was softest. Fifteen participants moved their hand with one of 9 inter-beat intervals (IBIs) ranging from 524 to 3,125 ms in 4 metrical level (ML) conditions ranging from 1 (one movement for each sound) to 4 (one movement for every 8th sound). The lowest relative variability (SD/IBI<1.5%) was obtained for the 3 longest IBIs (1600-3,125 ms) and MLs 3-4, significantly less than the smallest value (4-5% at 524-1024 ms) for any ML 1 condition in which all sounds are identical. Asynchronies were also more negative with higher ML. In conclusion, metrical subdivision provides information that facilitates temporal performance, which suggests an underlying neural multi-level mechanism capable of integrating information across levels. © 2013.

On the Problem of Determining Aggregation Numbers from Surface Tension Measurements.

Science.gov (United States)

Rusanov, Anatoly I

2017-11-07

In view of the recent discovery of variable aggregation numbers in the vicinity of the critical micelle concentration (CMC), the mass-action-law theory of the surface tension isotherm of a micellar solution with variable aggregation numbers is formulated both for nonionic and ionic surfactants. It is shown that the shape of the surface tension isotherm should be concave in the logarithmic scale above the CMC. Considering a change in the isotherm slope at the CMC apparent break point, the problems of determining the aggregation number for nonionic micelles and the degree of counterion binding for ionic micelles are discussed. In case of the aggregation number variability near the CMC, finding the aggregation number above the CMC apparent break point is considered and a computational scheme is elaborated, requiring a higher precision for experiment. Some experimental data from the literature are analyzed, and the method of estimating the degree of counterion binding is improved.

Long-term cloud condensation nuclei number concentration, particle number size distribution and chemical composition measurements at regionally representative observatories

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J. Schmale

2018-02-01

Full Text Available Aerosol–cloud interactions (ACI constitute the single largest uncertainty in anthropogenic radiative forcing. To reduce the uncertainties and gain more confidence in the simulation of ACI, models need to be evaluated against observations, in particular against measurements of cloud condensation nuclei (CCN. Here we present a data set – ready to be used for model validation – of long-term observations of CCN number concentrations, particle number size distributions and chemical composition from 12 sites on 3 continents. Studied environments include coastal background, rural background, alpine sites, remote forests and an urban surrounding. Expectedly, CCN characteristics are highly variable across site categories. However, they also vary within them, most strongly in the coastal background group, where CCN number concentrations can vary by up to a factor of 30 within one season. In terms of particle activation behaviour, most continental stations exhibit very similar activation ratios (relative to particles  > 20 nm across the range of 0.1 to 1.0 % supersaturation. At the coastal sites the transition from particles being CCN inactive to becoming CCN active occurs over a wider range of the supersaturation spectrum. Several stations show strong seasonal cycles of CCN number concentrations and particle number size distributions, e.g. at Barrow (Arctic haze in spring, at the alpine stations (stronger influence of polluted boundary layer air masses in summer, the rain forest (wet and dry season or Finokalia (wildfire influence in autumn. The rural background and urban sites exhibit relatively little variability throughout the year, while short-term variability can be high especially at the urban site. The average hygroscopicity parameter, κ, calculated from the chemical composition of submicron particles was highest at the coastal site of Mace Head (0.6 and lowest at the rain forest station ATTO (0.2–0.3. We performed closure

Variability and uncertainty in Swedish exposure factors for use in quantitative exposure assessments.

Science.gov (United States)

Filipsson, Monika; Öberg, Tomas; Bergbäck, Bo

2011-01-01

Information of exposure factors used in quantitative risk assessments has previously been compiled and reported for U.S. and European populations. However, due to the advancement of science and knowledge, these reports are in continuous need of updating with new data. Equally important is the change over time of many exposure factors related to both physiological characteristics and human behavior. Body weight, skin surface, time use, and dietary habits are some of the most obvious examples covered here. A wealth of data is available from literature not primarily gathered for the purpose of risk assessment. Here we review a number of key exposure factors and compare these factors between northern Europe--here represented by Sweden--and the United States. Many previous compilations of exposure factor data focus on interindividual variability and variability between sexes and age groups, while uncertainty is mainly dealt with in a qualitative way. In this article variability is assessed along with uncertainty. As estimates of central tendency and interindividual variability, mean, standard deviation, skewness, kurtosis, and multiple percentiles were calculated, while uncertainty was characterized using 95% confidence intervals for these parameters. The presented statistics are appropriate for use in deterministic analyses using point estimates for each input parameter as well as in probabilistic assessments. © 2010 Society for Risk Analysis.

Use of number by fish.

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Christian Agrillo

Full Text Available BACKGROUND: Research on human infants, mammals, birds and fish has demonstrated that rudimentary numerical abilities pre-date the evolution of human language. Yet there is controversy as to whether animals represent numbers mentally or rather base their judgments on non-numerical perceptual variables that co-vary with numerosity. To date, mental representation of number has been convincingly documented only for a few mammals. METHODOLOGY/PRINCIPAL FINDINGS: Here we used a training procedure to investigate whether mosquitofish could learn to discriminate between two and three objects even when denied access to non-numerical information. In the first experiment, fish were trained to discriminate between two sets of geometric figures. These varied in shape, size, brightness and distance, but no control for non-numerical variables was made. Subjects were then re-tested while controlling for one non-numerical variable at a time. Total luminance of the stimuli and the sum of perimeter of figures appeared irrelevant, but performance dropped to chance level when stimuli were matched for the cumulative surface area or for the overall space occupied by the arrays, indicating that these latter cues had been spontaneously used by the fish during the learning process. In a second experiment, where the task consisted of discriminating 2 vs 3 elements with all non-numerical variables simultaneously controlled for, all subjects proved able to learn the discrimination, and interestingly they did not make more errors than the fish in Experiment 1 that could access non-numerical information in order to accomplish the task. CONCLUSIONS/SIGNIFICANCE: Mosquitofish can learn to discriminate small quantities, even when non-numerical indicators of quantity are unavailable, hence providing the first evidence that fish, like primates, can use numbers. As in humans and non-human primates, genuine counting appears to be a 'last resort' strategy in fish, when no other

Variability in human body size

Science.gov (United States)

Annis, J. F.

1978-01-01

The range of variability found among homogeneous groups is described and illustrated. Those trends that show significantly marked differences between sexes and among a number of racial/ethnic groups are also presented. Causes of human-body size variability discussed include genetic endowment, aging, nutrition, protective garments, and occupation. The information is presented to aid design engineers of space flight hardware and equipment.

Statistical Dependence of Pipe Breaks on Explanatory Variables

Directory of Open Access Journals (Sweden)

Patricia Gómez-Martínez

2017-02-01

Full Text Available Aging infrastructure is the main challenge currently faced by water suppliers. Estimation of assets lifetime requires reliable criteria to plan assets repair and renewal strategies. To do so, pipe break prediction is one of the most important inputs. This paper analyzes the statistical dependence of pipe breaks on explanatory variables, determining their optimal combination and quantifying their influence on failure prediction accuracy. A large set of registered data from Madrid water supply network, managed by Canal de Isabel II, has been filtered, classified and studied. Several statistical Bayesian models have been built and validated from the available information with a technique that combines reference periods of time as well as geographical location. Statistical models of increasing complexity are built from zero up to five explanatory variables following two approaches: a set of independent variables or a combination of two joint variables plus an additional number of independent variables. With the aim of finding the variable combination that provides the most accurate prediction, models are compared following an objective validation procedure based on the model skill to predict the number of pipe breaks in a large set of geographical locations. As expected, model performance improves as the number of explanatory variables increases. However, the rate of improvement is not constant. Performance metrics improve significantly up to three variables, but the tendency is softened for higher order models, especially in trunk mains where performance is reduced. Slight differences are found between trunk mains and distribution lines when selecting the most influent variables and models.

7.1. Physical interpretation of the system of dosimetric variables

International Nuclear Information System (INIS)

Kovar, Z.

1984-01-01

Definitions and units are given of variables characterizing sources of ionizing radiation, the field of ionizing radiation in a material medium, interaction processes of ionizing radiation with matter, and the dose equivalent. The definitions consistently use SI units for nuclear sciences. (E.S.)

Variability of HOMA and QUICKI insulin sensitivity indices.

Science.gov (United States)

Žarković, Miloš; Ćirić, Jasmina; Beleslin, Biljana; Stojković, Mirjana; Savić, Slavica; Stojanović, Miloš; Lalić, Tijana

2017-07-01

Assessment of insulin sensitivity based on a single measurement of insulin and glucose, is both easy to understand and simple to perform. The tests most often used are HOMA and QUICKI. The aim of this study was to assess the biological variability of estimates of insulin sensitivity using HOMA and QUICKI indices. After a 12-h fast, blood was sampled for insulin and glucose determination. Sampling lasted for 90 min with an intersample interval of 2 min. A total of 56 subjects were included in the study, and in nine subjects sampling was done before and after weight reduction, so total number of analyzed series was 65. To compute the reference value of the insulin sensitivity index, averages of all 46 insulin and glucose samples were used. We also computed point estimates (single value estimates) of the insulin sensitivity index based on the different number of insulin/glucose samples (1-45 consecutive samples). To compute the variability of point estimates a bootstrapping procedure was used using 1000 resamples for each series and for each number of samples used to average insulin and glucose. Using a single insulin/glucose sample HOMA variability was 26.18 ± 4.31%, and QUICKI variability was 3.30 ± 0.54%. For 10 samples variability was 11.99 ± 2.22% and 1.62 ± 0.31% respectively. Biological variability of insulin sensitivity indices is significant, and it can be reduced by increasing the number of samples. Oscillations of insulin concentration in plasma are the major cause of variability of insulin sensitivity indices.

Impact analysis of flow variability in sizing kanbans

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Isaac Pergher

2014-02-01

Full Text Available The aim of this paper is to analyze the effects of variability flow, advocated by Factory Physics, in sizing Kanban production systems. The variability of flow presupposes that the variability of activities performed by a process is dissipated throughout the productive flow system, causing variations in the lead time, the work-in-process levels and the equipment availability, among others. To conduct the research, we created a didactic model of discrete event computer simulation. The proposed model aims to present the possible impacts caused by the variability flow in a production system regarding the sizing of the number of Kanbans cards, by using the results supplied by two different investigated scenarios. The main results of the research allow concluding that, by comparing the two scenarios developed in the model, the presence of variability in the production system caused an average increase of 32% in the number of Kanban cards (p=0,000. This implies that, in real productive systems, the study of Kanban sizing should consider the variability of individual operations, a fact often relegated as an assumption in the formulation from classical literature on the definition of the number of Kanbans, thus providing opportunities for the development of future research.

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

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A. Jafari

2016-02-01

profiles, which were then described, sampled, analyzed and classified according to the USDA soil classification system (16. The basic rationale is to set up a hypercube, the axes of which are the quantiles of rasters of environmental covariates, e.g., digital elevation model. Sampling evaluation was made using the HELS algorithm. This algorithm was written based on the study of Carre et al., 2007 (3 and run in R. Results and Discussion: The covariate dataset is represented by elevation, slope and wetness index (Table 2. All data layers were interpolated to a common grid of 30 m resolution. The size of the raster layer is 421 by 711 grid cells. Each of the three covariates is divided into four quantiles (Table 2. The hypercube character space has 43, i.e. 64 strata (Figure 5. The average number of grid cells within each stratum is therefore 4677 grid cells. The map of the covariate index (Figure 6 shows some patterns representative of the covariate variability. The values of the covariate index range between 0.0045 and 5.95. This means that some strata are very dense compared to others. This index allows us to explain if high or low relative weight of the sampling units (see below is due to soil sampling or covariate density. The strata with the highest density are in the areas with high geomorphology diversity. It means that geomorphology processes can cause the diversity and variability and it is in line with the geomorphology map (Figure 2. Of the 64 strata, 30.4% represent under-sampling, 60.2% represent adequate sampling and 9.4% represent over-sampling. Regarding the covariate index, most of the under-sampling appears in the high covariate index, where soil covariates are then highly variable. Actually, it is difficult to collect field samples in these highly variable areas (Figure 7. Also, most of the over-sampling was observed in areas with alow covariate index (Figure 7. We calculated the weights of all the sampling units and showed the results in Figure 8. One 64

Ultrahigh-dimensional variable selection method for whole-genome gene-gene interaction analysis

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Ueki Masao

2012-05-01

Full Text Available Abstract Background Genome-wide gene-gene interaction analysis using single nucleotide polymorphisms (SNPs is an attractive way for identification of genetic components that confers susceptibility of human complex diseases. Individual hypothesis testing for SNP-SNP pairs as in common genome-wide association study (GWAS however involves difficulty in setting overall p-value due to complicated correlation structure, namely, the multiple testing problem that causes unacceptable false negative results. A large number of SNP-SNP pairs than sample size, so-called the large p small n problem, precludes simultaneous analysis using multiple regression. The method that overcomes above issues is thus needed. Results We adopt an up-to-date method for ultrahigh-dimensional variable selection termed the sure independence screening (SIS for appropriate handling of numerous number of SNP-SNP interactions by including them as predictor variables in logistic regression. We propose ranking strategy using promising dummy coding methods and following variable selection procedure in the SIS method suitably modified for gene-gene interaction analysis. We also implemented the procedures in a software program, EPISIS, using the cost-effective GPGPU (General-purpose computing on graphics processing units technology. EPISIS can complete exhaustive search for SNP-SNP interactions in standard GWAS dataset within several hours. The proposed method works successfully in simulation experiments and in application to real WTCCC (Wellcome Trust Case–control Consortium data. Conclusions Based on the machine-learning principle, the proposed method gives powerful and flexible genome-wide search for various patterns of gene-gene interaction.

Variability in Resident Operative Hand Experience by Specialty.

Science.gov (United States)

Silvestre, Jason; Lin, Ines C; Levin, L Scott; Chang, Benjamin

2018-01-01

Recent attention has sought to standardize hand surgery training in the United States. This study analyzes the variability in operative hand experience for orthopedic and general surgery residents. Case logs for orthopedic and general surgery residency graduates were obtained from the American Council of Graduate Medical Education (2006-2007 to 2014-2015). Plastic surgery case logs were not available for comparison. Hand surgery case volumes were compared between specialties with parametric tests. Intraspecialty variation in orthopedic surgery was assessed between the bottom and top 10th percentiles in procedure categories. Case logs for 9605 general surgery residents and 5911 orthopedic surgery residents were analyzed. Orthopedic surgery residents performed a greater number of hand surgery cases than general surgery residents ( P < .001). Mean total hand experience ranged from 2.5 ± 4 to 2.8 ± 5 procedures for general surgery residents with no reported cases of soft tissue repairs, vascular repairs, and replants. Significant intraspecialty variation existed in orthopedic surgery for all hand procedure categories (range, 3.3-15.0). As the model for hand surgery training evolves, general surgeons may represent an underutilized talent pool to meet the critical demand for hand surgeon specialists. Future research is needed to determine acceptable levels of training variability in hand surgery.

Patient-centered variables in primary and team nursing.

Science.gov (United States)

Hamera, E; O'Connell, K A

1981-03-01

Patient-centered variables and their relationship to primary and team nursing have rarely been studied. In the present study the investigation focused on the following patient-centered variables: nurturance received, patient involvement, and frequency of nurse-patient contacts. Baseline observational data were collected on 12 adult medical patients experiencing team nursing care. A primary nursing care approach was then implemented on the same nursing unit, and 6 months later 12 patients were observed under this system. Patients were directly observed 24 hours a day for 5 days of hospitalization and audiotaped, using a specimen record method. This method produced transcripts that were coded for nurturance, involvement, and nurse-patient contacts. Results of the study showed that there were no differences between primary and team nursing care groups in the number of contacts, nurturance, or patient involvement with all nursing personnel or with professional nurses. However, when the primary group was adjusted to include only those patients for whom primary nursing care was fully implemented, the primary group received more nurturance (p less than .05) and had a tendency to be more active involved than did the team group (p less than .10). These findings indicate that the institution of primary nursing care is related to increased quality of nursing care.

Large number discrimination in newborn fish.

Directory of Open Access Journals (Sweden)

Laura Piffer

Full Text Available Quantitative abilities have been reported in a wide range of species, including fish. Recent studies have shown that adult guppies (Poecilia reticulata can spontaneously select the larger number of conspecifics. In particular the evidence collected in literature suggest the existence of two distinct systems of number representation: a precise system up to 4 units, and an approximate system for larger numbers. Spontaneous numerical abilities, however, seem to be limited to 4 units at birth and it is currently unclear whether or not the large number system is absent during the first days of life. In the present study, we investigated whether newborn guppies can be trained to discriminate between large quantities. Subjects were required to discriminate between groups of dots with a 0.50 ratio (e.g., 7 vs. 14 in order to obtain a food reward. To dissociate the roles of number and continuous quantities that co-vary with numerical information (such as cumulative surface area, space and density, three different experiments were set up: in Exp. 1 number and continuous quantities were simultaneously available. In Exp. 2 we controlled for continuous quantities and only numerical information was available; in Exp. 3 numerical information was made irrelevant and only continuous quantities were available. Subjects successfully solved the tasks in Exp. 1 and 2, providing the first evidence of large number discrimination in newborn fish. No discrimination was found in experiment 3, meaning that number acuity is better than spatial acuity. A comparison with the onset of numerical abilities observed in shoal-choice tests suggests that training procedures can promote the development of numerical abilities in guppies.

Modeling Scramjet Flows with Variable Turbulent Prandtl and Schmidt Numbers

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Xiao, X.; Hassan, H. A.; Baurle, R. A.

2006-01-01

A complete turbulence model, where the turbulent Prandtl and Schmidt numbers are calculated as part of the solution and where averages involving chemical source terms are modeled, is presented. The ability of avoiding the use of assumed or evolution Probability Distribution Functions (PDF's) results in a highly efficient algorithm for reacting flows. The predictions of the model are compared with two sets of experiments involving supersonic mixing and one involving supersonic combustion. The results demonstrate the need for consideration of turbulence/chemistry interactions in supersonic combustion. In general, good agreement with experiment is indicated.

Improved variable reduction in partial least squares modelling by Global-Minimum Error Uninformative-Variable Elimination.

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Andries, Jan P M; Vander Heyden, Yvan; Buydens, Lutgarde M C

2017-08-22

The calibration performance of Partial Least Squares regression (PLS) can be improved by eliminating uninformative variables. For PLS, many variable elimination methods have been developed. One is the Uninformative-Variable Elimination for PLS (UVE-PLS). However, the number of variables retained by UVE-PLS is usually still large. In UVE-PLS, variable elimination is repeated as long as the root mean squared error of cross validation (RMSECV) is decreasing. The set of variables in this first local minimum is retained. In this paper, a modification of UVE-PLS is proposed and investigated, in which UVE is repeated until no further reduction in variables is possible, followed by a search for the global RMSECV minimum. The method is called Global-Minimum Error Uninformative-Variable Elimination for PLS, denoted as GME-UVE-PLS or simply GME-UVE. After each iteration, the predictive ability of the PLS model, built with the remaining variable set, is assessed by RMSECV. The variable set with the global RMSECV minimum is then finally selected. The goal is to obtain smaller sets of variables with similar or improved predictability than those from the classical UVE-PLS method. The performance of the GME-UVE-PLS method is investigated using four data sets, i.e. a simulated set, NIR and NMR spectra, and a theoretical molecular descriptors set, resulting in twelve profile-response (X-y) calibrations. The selective and predictive performances of the models resulting from GME-UVE-PLS are statistically compared to those from UVE-PLS and 1-step UVE, one-sided paired t-tests. The results demonstrate that variable reduction with the proposed GME-UVE-PLS method, usually eliminates significantly more variables than the classical UVE-PLS, while the predictive abilities of the resulting models are better. With GME-UVE-PLS, a lower number of uninformative variables, without a chemical meaning for the response, may be retained than with UVE-PLS. The selectivity of the classical UVE method

Implementation of sepsis algorithm by nurses in the intensive care unit

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Paula Pedroso Peninck

2012-04-01

Full Text Available Sepsis is defined as a clinical syndrome consisting of a systemic inflammatory response associated to an infection, which may determine malfunction or failure of multiple organs. This research aims to verify the application of implementation of sepsis algorithm by nurses in the Intensive Care Unit and create an operational nursing assistance guide. This is an exploratory, descriptive study with quantitative approach. A data collection instrument based on relevant literature was elaborated, assessed, corrected and validated. The sample consisted of 20 intensive care unit nurses. We obtained satisfactory evaluations on nurses’ performance, but some issues did not reach 50% accuracy. We emphasize the importance of greater numbers of nurses getting acquainted and correctly applying the sepsis algorithm. Based on the above, an operational septic patient nursing assistance guide was created, based on the difficulties that arose vis-à-vis the variables applied in research and relevant literature.

Seasonal variability of faecal indicator bacteria numbers and die-off rates in the Red River basin, North Viet Nam

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Nguyen, Huong Thi Mai; Le, Quynh Thi Phuong; Garnier, J.; Janeau, J.-L.; Rochelle-Newall, E.

2016-02-01

The Red River is the second largest river in Viet Nam and constitutes the main water source for a large percentage of the population of North Viet Nam. Here we present the results of an annual survey of Escherichia coli (EC) and Total Coliforms (TC) in the Red River basin, North Viet Nam. The objective of this work was to obtain information on faecal indicator bacteria (FIB) numbers over an annual cycle and, secondly, to determine the die-off rates of these bacterial indicators. Monthly observations at 10 stations from July 2013-June 2014 showed that TC and EC reached as high as 39100 cfu (colony forming units) 100 ml-1 and 15300 colonies 100 ml-1, respectively. We observed a significant seasonal difference for TC (p < 0.05) with numbers being higher during the wet season. In contrast, no significant seasonal difference was found for EC. The FIB die-off rates ranged from 0.01 d-1 to a maximum of 1.13 d-1 for EC and from 0.17 d-1 to 1.33 d-1 for TC. Die-off rates were significantly higher for free bacteria than for total (free + particle attached) bacteria, suggesting that particle attachment provided a certain level of protection to FIB in this system.

Role of Turbulent Prandtl Number on Heat Flux at Hypersonic Mach Number

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Xiao, X.; Edwards, J. R.; Hassan, H. A.

2004-01-01

Present simulation of turbulent flows involving shock wave/boundary layer interaction invariably overestimates heat flux by almost a factor of two. One possible reason for such a performance is a result of the fact that the turbulence models employed make use of Morkovin's hypothesis. This hypothesis is valid for non-hypersonic Mach numbers and moderate rates of heat transfer. At hypersonic Mach numbers, high rates of heat transfer exist in regions where shock wave/boundary layer interactions are important. As a result, one should not expect traditional turbulence models to yield accurate results. The goal of this investigation is to explore the role of a variable Prandtl number formulation in predicting heat flux in flows dominated by strong shock wave/boundary layer interactions. The intended applications involve external flows in the absence of combustion such as those encountered in supersonic inlets. This can be achieved by adding equations for the temperature variance and its dissipation rate. Such equations can be derived from the exact Navier-Stokes equations. Traditionally, modeled equations are based on the low speed energy equation where the pressure gradient term and the term responsible for energy dissipation are ignored. It is clear that such assumptions are not valid for hypersonic flows. The approach used here is based on the procedure used in deriving the k-zeta model, in which the exact equations that governed k, the variance of velocity, and zeta, the variance of vorticity, were derived and modeled. For the variable turbulent Prandtl number, the exact equations that govern the temperature variance and its dissipation rate are derived and modeled term by term. The resulting set of equations are free of damping and wall functions and are coordinate-system independent. Moreover, modeled correlations are tensorially consistent and invariant under Galilean transformation. The final set of equations will be given in the paper.

46 CFR 108.525 - Survival craft number and arrangement.

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2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Survival craft number and arrangement. 108.525 Section... UNITS DESIGN AND EQUIPMENT Lifesaving Equipment § 108.525 Survival craft number and arrangement. (a... arrangement of survival craft: (1) Lifeboats with an aggregate capacity to accommodate the total number of...

Multiple-locus variable-number tandem repeat analysis for molecular typing of Aspergillus fumigatus

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Chermette René

2010-12-01

Full Text Available Abstract Background Multiple-locus variable-number tandem repeat (VNTR analysis (MLVA is a prominent subtyping method to resolve closely related microbial isolates to provide information for establishing genetic patterns among isolates and to investigate disease outbreaks. The usefulness of MLVA was recently demonstrated for the avian major pathogen Chlamydophila psittaci. In the present study, we developed a similar method for another pathogen of birds: the filamentous fungus Aspergillus fumigatus. Results We selected 10 VNTR markers located on 4 different chromosomes (1, 5, 6 and 8 of A. fumigatus. These markers were tested with 57 unrelated isolates from different hosts or their environment (53 isolates from avian species in France, China or Morocco, 3 isolates from humans collected at CHU Henri Mondor hospital in France and the reference strain CBS 144.89. The Simpson index for individual markers ranged from 0.5771 to 0.8530. A combined loci index calculated with all the markers yielded an index of 0.9994. In a second step, the panel of 10 markers was used in different epidemiological situations and tested on 277 isolates, including 62 isolates from birds in Guangxi province in China, 95 isolates collected in two duck farms in France and 120 environmental isolates from a turkey hatchery in France. A database was created with the results of the present study http://minisatellites.u-psud.fr/MLVAnet/. Three major clusters of isolates were defined by using the graphing algorithm termed Minimum Spanning Tree (MST. The first cluster comprised most of the avian isolates collected in the two duck farms in France, the second cluster comprised most of the avian isolates collected in poultry farms in China and the third one comprised most of the isolates collected in the turkey hatchery in France. Conclusions MLVA displayed excellent discriminatory power. The method showed a good reproducibility. MST analysis revealed an interesting clustering with a

Association between number of cell phone contracts and brain tumor incidence in nineteen U.S. States.

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Lehrer, Steven; Green, Sheryl; Stock, Richard G

2011-02-01

Some concern has arisen about adverse health effects of cell phones, especially the possibility that the low power microwave-frequency signal transmitted by the antennas on handsets might cause brain tumors or accelerate the growth of subclinical tumors. We analyzed data from the Statistical Report: Primary Brain Tumors in the United States, 2000-2004 and 2007 cell phone subscription data from the Governing State and Local Sourcebook. There was a significant correlation between number of cell phone subscriptions and brain tumors in nineteen US states (r = 0.950, P cell phone subscriptions and brain tumors could be due solely to the fact that some states, such as New York, have much larger populations than other states, such as North Dakota, multiple linear regression was performed with number of brain tumors as the dependent variable, cell phone subscriptions, population, mean family income and mean age as independent variables. The effect of cell phone subscriptions was significant (P = 0.017), and independent of the effect of mean family income (P = 0.894), population (P = 0.003) and age (0.499). The very linear relationship between cell phone usage and brain tumor incidence is disturbing and certainly needs further epidemiological evaluation. In the meantime, it would be prudent to limit exposure to all sources of electro-magnetic radiation.

Obstacles to Scientific Research in Light of a Number of Variables

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Algadheeb, Nourah A.; Almeqren, Monira A.

2014-01-01

The present study aimed to identify the scientific research obstacles facing faculty members in the College of Education at Princess Nora bint Abdul Rahman University (PNU) and to determine the differences in the obstacles according to age, academic rank, scientific specialty, marital status, number of completed studies, and time since the last…

Nevada test site underground storage tank number 12-13-1: Nevada division of emergency management case number H931130E corrective action unit 450. Closure report

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NONE

1997-01-01

The project site was identified as an abandoned Underground Storage Tank (UST) to be closed under the Department of Energy/Nevada Operations Office (DOE/NV) Environmental Restoration Division (ERD) Program during Fiscal Year 1993. The United States Environmental Protection Agency (EPA) requires that before permanent closure is completed an assessment of the site must take place. The Nevada Division of Environmental Protection (NDEP) requires assessment and corrective actions for a petroleum substance in the soil which exceeds 100 milligrams per kilogram (mg/kg). Subsequent to the tank removal, a hydrocarbon release was identified at the site. The release was reported to the NDEP by DOE/NV on November 30, 1993. Nevada Division of Environmental Management (NDEM) Case Number H931130E was assigned. This final closure report documents the assessment and corrective actions taken for the hydrocarbon release identified at the site. The Notification of Closure, EPA Form 7530-1 dated March 22, 1994, is provided in Appendix A. A 45-day report documenting the notification for a hydrocarbon release was submitted to NDEP on April 6, 1994.

Allocating multiple units

DEFF Research Database (Denmark)

Tranæs, Torben; Krishna, Kala

2002-01-01

This paper studies the allocation and rent distribution in multi-unit, combinatorial-bid auctions under complete information. We focus on the natural multi-unit analogue of the first-price auction, where buyers bid total payments, pay their bids, and where the seller allocates goods to maximize his...... auction, which is the multi unit analogue of a second-price auction. Furthermore, we characterize these equilibria when valuations take a number of different forms: diminishing marginal valuations, increasing average valuations, and marginal valuations with single turning points...

A Modified Entropy Generation Number for Heat Exchangers

Institute of Scientific and Technical Information of China (English)

无

1996-01-01

This paper demonstrates the difference between the entropy generation number method proposed by Bejian and the method of entropy generation per unit amount of heat transferred in analyzing the ther-modynamic performance of heat exchangers,points out the reason for leading to the above difference.A modified entropy generation number for evaluating the irreversibility of heat exchangers is proposed which is in consistent with the entropy generation per unit amount of heat transferred in entropy generation analysis.The entropy generated by friction is also investigated.Results show that when the entropy generated by friction in heat exchangers in taken into account,there is a minimum total entropy generation number while the NTU and the ratio of heat capacity rates vary.The existence of this minimum is the prerequisite of heat exchanger optimization.

Variables in full-body ultraviolet B treatment of skin diseases

DEFF Research Database (Denmark)

Wulf, Hans Christian; Heydenreich, Jakob; Philipsen, Peter A

2010-01-01

Ultraviolet B (UVB) treatment is most often performed according to a fixed schedule, not necessarily considering important variables such as UV intensity, type of UVB source and skin pigmentation. These variables can rather easily be taken into consideration by the right choice of dosing unit...... burning....

Life style factors and number of chronic diseases

Directory of Open Access Journals (Sweden)

Mustehsan, Huma

2011-05-01

Full Text Available BACKGROUND: People all around the world are more concerned with living a long and healthy life, rather than just living longer. Many studies have examined the effects of lifestyle on the risk of developing chronic diseases, but typically, they focus on only one specific behavior. Individuals often follow a lifestyle pattern which combines more than one behavior. This paper examines the combined effect of several lifestyle factors on the number of chronic diseases.OBJECTIVE: The goal of this study was to determine how different lifestyle factors influence the number of chronic diseases a person can have.METHODS: Data from the survey “Health and Well-being in the Transitions” (2000 were used. Dependent variable was number of chronic diseases which ranged from zero to five. Independent variables included the level of physical activity, variables based on food frequency questions, and other behavioral activities, adjusted for age and gender. Generalized linear model with Poisson distribution was used for analysis.RESULTS: The analysis showed that males have more diseases than females if other factors are controlled (B=0.182, p=0.001. Diseases increase by age (B=0.021, p=0.000. Those who used dairy products daily had smaller number of diseases (B= -0.145, p=0.012. Those who used vegetable oil 3-7 days a week had smaller number of diseases than those who use it 0-2 days a week (B= -0.224, p=0.058. Other food frequencies and ever smoking had no clear association with number of diseases.CONCLUSION: Increasing age and male gender are two factors which are associated with larger number of chronic diseases. Regular use of vegetable oil and dairy products seems to be important towards the path of a healthier life.

Improved variable reduction in partial least squares modelling based on predictive-property-ranked variables and adaptation of partial least squares complexity.

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Andries, Jan P M; Vander Heyden, Yvan; Buydens, Lutgarde M C

2011-10-31

The calibration performance of partial least squares for one response variable (PLS1) can be improved by elimination of uninformative variables. Many methods are based on so-called predictive variable properties, which are functions of various PLS-model parameters, and which may change during the variable reduction process. In these methods variable reduction is made on the variables ranked in descending order for a given variable property. The methods start with full spectrum modelling. Iteratively, until a specified number of remaining variables is reached, the variable with the smallest property value is eliminated; a new PLS model is calculated, followed by a renewed ranking of the variables. The Stepwise Variable Reduction methods using Predictive-Property-Ranked Variables are denoted as SVR-PPRV. In the existing SVR-PPRV methods the PLS model complexity is kept constant during the variable reduction process. In this study, three new SVR-PPRV methods are proposed, in which a possibility for decreasing the PLS model complexity during the variable reduction process is build in. Therefore we denote our methods as PPRVR-CAM methods (Predictive-Property-Ranked Variable Reduction with Complexity Adapted Models). The selective and predictive abilities of the new methods are investigated and tested, using the absolute PLS regression coefficients as predictive property. They were compared with two modifications of existing SVR-PPRV methods (with constant PLS model complexity) and with two reference methods: uninformative variable elimination followed by either a genetic algorithm for PLS (UVE-GA-PLS) or an interval PLS (UVE-iPLS). The performance of the methods is investigated in conjunction with two data sets from near-infrared sources (NIR) and one simulated set. The selective and predictive performances of the variable reduction methods are compared statistically using the Wilcoxon signed rank test. The three newly developed PPRVR-CAM methods were able to retain

Investigating Reliabilities of Intraindividual Variability Indicators

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Wang, Lijuan; Grimm, Kevin J.

2012-01-01

Reliabilities of the two most widely used intraindividual variability indicators, "ISD[superscript 2]" and "ISD", are derived analytically. Both are functions of the sizes of the first and second moments of true intraindividual variability, the size of the measurement error variance, and the number of assessments within a burst. For comparison,…

Spatial variability of soil carbon across Mexico and the United States

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Vargas, R.; Guevara, M.; Cruz Gaistardo, C.; Paz, F.; de Jong, B.; Etchevers, J.

2015-12-01

Soil organic carbon (SOC) is directly linked to soil quality, food security, and land use/global environmental change. We use publicly available information on SOC and couple it with digital elevation models and derived terrain attributes using a machine learning approach. We found a strong spatial dependency of SOC across the United States, but less spatial dependency of SOC across Mexico. Using High Performance Computing (HPC) we derived a 1 km resolution map of SOC across Mexico and the United States. We tested different machine learning methods (e.g., kernel based, tree based and/or Geo-statistics approaches) for computational efficiency and statistical accuracy. Using random forest combined with geo-statistics we were able to explain >70% of SOC variance for Mexico and >40% in the case of the United States via cross validation. These results compare with other published estimates of SOC at 1km resolution that only explain <30% of SOC variance across the world. Topographic attributes derived from digital elevation models are freely available globally at fine spatial resolution (<100 m), and this information allowed us to make predictions of SOC at fine scales. We further tested this approach using SOC information from the International Soil Carbon Network to predict SOC in other regions of the world. We conclude that this approach (using public information and open source platforms for data analysis) could be implemented to predict detailed explicit information of SOC across different spatial scales.

The CT (Hounsfield unit) number of brain tissue in healthy infants. A new reliable method for detection of possible degenerative disease.

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Boris, P; Bundgaard, F; Olsen, A

1987-01-01

It is difficult to correlate CT Hounsfield unit (H. U.) numbers from one CT investigation to another and from one CT scanner to another, especially when dealing with small changes in the brain substance, as in degenerative brain diseases in children. By subtracting the mean value of cerebrospinal fluid (CSF) from the mean value of grey and white matter, it is possible to remove most of the errors due, for example, to maladjustments, short and long-term drift, X-ray fan, and detector asymmetry. Measurements of white and grey matter using these methods showed CT H. U. numbers changing from 15 H. U. to 22 H. U. in white matter and 23 H. U. to 30 H. U. in grey matter in 86 healthy infants aged 0-5 years. In all measurements, the difference between grey and white matter was exactly 8 H. U. The method has proven to be highly accurate and reproducible.

The potential impacts of climate variability and change on health impacts of extreme weather events in the United States.

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Greenough, G; McGeehin, M; Bernard, S M; Trtanj, J; Riad, J; Engelberg, D

2001-05-01

Extreme weather events such as precipitation extremes and severe storms cause hundreds of deaths and injuries annually in the United States. Climate change may alter the frequency, timing, intensity, and duration of these events. Increases in heavy precipitation have occurred over the past century. Future climate scenarios show likely increases in the frequency of extreme precipitation events, including precipitation during hurricanes, raising the risk of floods. Frequencies of tornadoes and hurricanes cannot reliably be projected. Injury and death are the direct health impacts most often associated with natural disasters. Secondary effects, mediated by changes in ecologic systems and public health infrastructure, also occur. The health impacts of extreme weather events hinge on the vulnerabilities and recovery capacities of the natural environment and the local population. Relevant variables include building codes, warning systems, disaster policies, evacuation plans, and relief efforts. There are many federal, state, and local government agencies and nongovernmental organizations involved in planning for and responding to natural disasters in the United States. Future research on health impacts of extreme weather events should focus on improving climate models to project any trends in regional extreme events and as a result improve public health preparedness and mitigation. Epidemiologic studies of health effects beyond the direct impacts of disaster will provide a more accurate measure of the full health impacts and will assist in planning and resource allocation.

Evaluation of a highly discriminating multiplex multi-locus variable-number of tandem-repeats (MLVA) analysis for Vibrio cholerae.

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Olsen, Jaran S; Aarskaug, Tone; Skogan, Gunnar; Fykse, Else Marie; Ellingsen, Anette Bauer; Blatny, Janet M

2009-09-01

Vibrio cholerae is the etiological agent of cholera and may be used in bioterror actions due to the easiness of its dissemination, and the public fear for acquiring the cholera disease. A simple and highly discriminating method for connecting clinical and environmental isolates of V. cholerae is needed in microbial forensics. Twelve different loci containing variable numbers of tandem-repeats (VNTRs) were evaluated in which six loci were polymorphic. Two multiplex reactions containing PCR primers targeting these six VNTRs resulted in successful DNA amplification of 142 various environmental and clinical V. cholerae isolates. The genetic distribution inside the V. cholerae strain collection was used to evaluate the discriminating power (Simpsons Diversity Index=0.99) of this new MLVA analysis, showing that the assay have a potential to differentiate between various strains, but also to identify those isolates which are collected from a common V. cholerae outbreak. This work has established a rapid and highly discriminating MLVA assay useful for track back analyses and/or forensic studies of V. cholerae infections.

Variable stiffness and damping MR isolator

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Zhang, X Z; Wang, X Y; Li, W H; Kostidis, K [University of Wollongong, School of Mechanical, Materials and Mechatronic Engineering, NSW 2522 (Australia)], E-mail: weihuali@uow.edu.au

2009-02-01

This paper presents the development of a magnetorheological (MR) fluid-based variable stiffness and damping isolator for vibration suppressions. The MR fluid isolator used a sole MR control unit to achieve the variable stiffness and damping in stepless and relative large scope. A mathematical model of the isolator was derived, and a prototype of the MR fluid isolator was fabricated and its dynamic behavior was measured in vibration under various applied magnetic fields. The parameters of the model under various magnetic fields were identified and the dynamic performances of isolator were evaluated.

The most common spoligotype of Mycobacterium bovis isolated in the world and the recommended loci for VNTR typing; A systematic review.

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Ghavidel, Mahdis; Mansury, Davood; Nourian, Kimiya; Ghazvini, Kiarash

2018-03-22

Mycobacterium bovis is a neglected zoonotic organism that epidemiological studies are of crucial importance in identifying its source, control it and prevent it from spreading. The aim of this study was to investigate the most common spoligotypes of Mycobacterium bovis circulating around the world and introduce the most and least strong determine powers of loci for VNTR. We have used different databases such as ISC, science direct, Embase (Elsevier), Web of Science, Scopus and Medline via PubMed. Searches were performed by key words including: Mycobacterium bovis, MIRU -VNTR, spoligotyping and discrimination power. Finally, thirty-one articles were selected after filtering out some titles, abstracts and full texts. Spoligotype SB0120 was the most common circulating type on several continents while SB0121 existed in Europe, Africa and America. SB0140 was also detected in Asia, Europe and America. QUB3232 and QUB11b were more appropriate loci among the loci with high discriminatory power. MIRU 10 and MIRU4 were among the loci with poor discriminatory power. Taking the published data into consideration, SB0120 and SB0121 are predominant spoligotypes of M. bovis circulating among animals around the world. Determining the most common spoligotype of M. bovis is the key to find source of infection, control and prevent the disease. Copyright © 2018 Elsevier Ltd. All rights reserved.

Ambiguity in Units and the Referents: Two Cases in Rational Number Operations

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Rathouz, Margaret

2010-01-01

I explore the impact of ambiguous referral to the unit on understanding of decimal and fraction operations during episodes in two different mathematics courses for pre-service teachers (PSTs). In one classroom, the instructor introduces a rectangular area diagram to help the PSTs visualize decimal multiplication. A transcript from this classroom…

Poison control center - Emergency number (image)

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For a poison emergency call 1-800-222-1222 anywhere in the United States. This national hotline number will let you ... is a free and confidential service. All local poison control centers in the U.S. use this national ...

Area vs. density: influence of visual variables and cardinality knowledge in early number comparison.

Science.gov (United States)

Abreu-Mendoza, Roberto A; Soto-Alba, Elia E; Arias-Trejo, Natalia

2013-01-01

Current research in the number development field has focused in individual differences regarding the acuity of children's approximate number system (ANS). The most common task to evaluate children's acuity is through non-symbolic numerical comparison. Efforts have been made to prevent children from using perceptual cues by controlling the visual properties of the stimuli (e.g., density, contour length, and area); nevertheless, researchers have used these visual controls interchangeably. Studies have also tried to understand the relation between children's cardinality knowledge and their performance in a number comparison task; divergent results may in fact be rooted in the use of different visual controls. The main goal of the present study is to explore how the usage of different visual controls (density, total filled area, and correlated and anti-correlated area) affects children's performance in a number comparison task, and its relationship to children's cardinality knowledge. For that purpose, 77 preschoolers participated in three tasks: (1) counting list elicitation to test whether children could recite the counting list up to ten, (2) give a number to evaluate children's cardinality knowledge, and (3) number comparison to evaluate their ability to compare two quantities. During this last task, children were asked to point at the set with more geometric figures when two sets were displayed on a screen. Children were exposed only to one of the three visual controls. Results showed that overall, children performed above chance in the number comparison task; nonetheless, density was the easiest control, while correlated and anti-correlated area was the most difficult in most cases. Only total filled area was sensitive to discriminate cardinal principal knowers from non-cardinal principal knowers. How this finding helps to explain conflicting evidence from previous research, and how the present outcome relates to children's number word knowledge is discussed.

The Evolution of the Number of Tourists accommodated in Arad

Directory of Open Access Journals (Sweden)

Sergiu Rusu

2014-12-01

Full Text Available The paper analyses the evolution of the number of tourists accommodated in Arad between January 2006 and September 2009. For this purpose we have used the statistics data from the official sites. As variables we chose: X – independent variable - Total tourist arrival and accommodated in Arad, Y - dependent variable - Tourists staying in hotels.

New polymorphisms within the variable number tandem repeat (VNTR) 7 locus of Mycobacterium avium subsp. paratuberculosis.

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Fawzy, Ahmad; Zschöck, Michael; Ewers, Christa; Eisenberg, Tobias

2016-06-01

Variable number tandem repeat (VNTR) is a frequently employed typing method of Mycobacterium avium paratuberculosis (MAP) isolates. Based on whole genome sequencing in a previous study, allelic diversity at some VNTR loci seems to over- or under-estimate the actual phylogenetic variance among isolates. Interestingly, two closely related isolates on one farm showed polymorphism at the VNTR 7 locus, raising concerns about the misleading role that it might play in genotyping. We aimed to investigate the underlying basis of VNTR 7-polymorphism by analyzing sequence data for published genomes and field isolates of MAP and other M. avium complex (MAC) members. In contrast to MAP strains from cattle, strains from sheep displayed an "imperfect" repeat within VNTR 7, which was identical to respective allele types in other MAC genomes. Subspecies- and strain-specific single nucleotide polymorphisms (SNPs) and two novel (16 and 56 bp) repeats were detected. Given the combination of the three existing repeats, there are at least five different patterns for VNTR 7. The present findings highlight a higher polymorphism and probable instability of VNTR 7 locus that needs to be considered and challenged in future studies. Until then, sequencing of this locus in future studies is important to correctly assign the underlying allele types.(1). Copyright © 2016 Elsevier Ltd. All rights reserved.

The effect of the number of consecutive night shifts on diurnal rhythms in cortisol, melatonin and heart rate variability (HRV)

DEFF Research Database (Denmark)

Jensen, Marie Aarrebo; Garde, Anne Helene; Kristiansen, Jesper

2016-01-01

PURPOSE: The purpose of this review is to summarize the current knowledge from field studies on how many consecutive night shifts are required for adaptation of diurnal rhythms in cortisol, melatonin and heart rate variability (HRV) to night work. METHODS: A systematic search of the databases Pub...... recordings for HRV. Most of the studies in the review were small studies with less than 30 participants, and most studies evaluated diurnal rhythms after only two consecutive night shifts whereas only six studies used seven or more consecutive night shifts. The majority of studies found that adaptation...... to night work had not occurred after two consecutive night shifts, whereas a small number found evidence for full adaptation after seven consecutive night shifts based on diurnal rhythms in cortisol and melatonin. CONCLUSION: There are methodological differences in the field studies analyzing diurnal...

LAND JUDGING AND PLANT NUTRITION, A PROGRAMMED INSTRUCTION UNIT, REPORT NUMBER 13.

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LONG, GILBERT A.

A UNIT OF PROGRAMED LEARNING MATERIALS WAS PRESENTED ON THE PRINCIPLES AND PROCEDURES OF LAND JUDGING AND PLANT NUTRITION. IN HIS PREPARATION, THE AUTHOR FIRST IDENTIFIED PRINCIPLES AND FACTS NECESSARY FOR EFFECTIVE LAND CLASSIFICATION AND PLANT NUTRITION BY EXAMINING RELEVANT SCIENTIFIC REPORTS. USING THIS INFORMATION, HE THEN FORMED A TEAM OF 16…

United States Air Force Statistical Digest 1947, Second Annual Number

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1948-08-01

Type and Series--Number Inetalled and Status of spere Enginell: lIlar 1944 to Dec 1947•••• ;, ••••••••••••••••••••••••• Tabla 99.-- Se!.o~ed Aircraft

VARIABLE STARS IN THE GLOBULAR CLUSTER NGC 2808

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Kunder, Andrea; Walker, Alistair R.; Stetson, Peter B.; Catelan, Márcio; Amigo, Pía

2013-01-01

The first calibrated broadband BVI time-series photometry is presented for the variable stars in NGC 2808, with observations spanning a range of 28 years. We have also redetermined the variability types and periods for the variable stars identified previously by Corwin et al., revising the number of probable fundamental-mode RR Lyrae variables (RR0) to 11 and the number of first-overtone variables (RR1) to five. Our observations were insufficient to discern the nature of the previously identified RR1 star, V24, and the tentatively identified RR1 star, V13. These two variables are ∼0.8 mag brighter than the RR Lyrae variables, appear to have somewhat erratic period and/or luminosity changes, and lie inside the RR Lyrae instability strip. Curiously, all but one of the RR Lyrae stars studied in this relatively metal-rich cluster exhibit the Blazhko phenomenon, an effect thought to occur with higher frequency in metal-poor environments. The mean periods of the RR0 and RR1 variables are (P) RR0 = 0.56 ± 0.01 d and RR1 = 0.30 ± 0.02 d, respectively, supporting an Oosterhoff I classification of the cluster. On the other hand, the number ratio of RR1-to-RR0-type variables is high, though not unprecedented, for an Oosterhoff I cluster. The RR Lyrae variables have no period shifts at a given amplitude compared to the M3 variables, making it unlikely that these variables are He enhanced. Using the recent recalibration of the RR Lyrae luminosity scale by Catelan and Cortés, a mean distance modulus of (m – M) V = 15.57 ± 0.13 mag for NGC 2808 is obtained, in good agreement with that determined here from its type II Cepheid and SX Phoenicis population. Our data have also allowed the discovery of two new candidate SX Phoenicis stars and an eclipsing binary in the blue straggler region of the NGC 2808 color-magnitude diagram.

Dynamic of Mutational Events in Variable Number Tandem Repeats of Escherichia coli O157:H7

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A. V. Bustamante

2013-01-01

Full Text Available VNTRs regions have been successfully used for bacterial subtyping; however, the hypervariability in VNTR loci is problematic when trying to predict the relationships among isolates. Since few studies have examined the mutation rate of these markers, our aim was to estimate mutation rates of VNTRs specific for verotoxigenic E. coli O157:H7. The knowledge of VNTR mutational rates and the factors affecting them would make MLVA more effective for epidemiological or microbial forensic investigations. For this purpose, we analyzed nine loci performing parallel, serial passage experiments (PSPEs on 9 O157:H7 strains. The combined 9 PSPE population rates for the 8 mutating loci ranged from 4.4 × 10−05 to 1.8 × 10−03 mutations/generation, and the combined 8-loci mutation rate was of 2.5 × 10−03 mutations/generation. Mutations involved complete repeat units, with only one point mutation detected. A similar proportion between single and multiple repeat changes was detected. Of the 56 repeat mutations, 59% were insertions and 41% were deletions, and 72% of the mutation events corresponded to O157-10 locus. For alleles with up to 13 UR, a constant and low mutation rate was observed; meanwhile longer alleles were associated with higher and variable mutation rates. Our results are useful to interpret data from microevolution and population epidemiology studies and particularly point out that the inclusion or not of O157-10 locus or, alternatively, a differential weighting data according to the mutation rates of loci must be evaluated in relation with the objectives of the proposed study.

MAXIMUM PRINCIPLE FOR SUBSONIC FLOW WITH VARIABLE ENTROPY

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B. Sizykh Grigory

2017-01-01

Full Text Available Maximum principle for subsonic flow is fair for stationary irrotational subsonic gas flows. According to this prin- ciple, if the value of the velocity is not constant everywhere, then its maximum is achieved on the boundary and only on the boundary of the considered domain. This property is used when designing form of an aircraft with a maximum critical val- ue of the Mach number: it is believed that if the local Mach number is less than unit in the incoming flow and on the body surface, then the Mach number is less then unit in all points of flow. The known proof of maximum principle for subsonic flow is based on the assumption that in the whole considered area of the flow the pressure is a function of density. For the ideal and perfect gas (the role of diffusion is negligible, and the Mendeleev-Clapeyron law is fulfilled, the pressure is a function of density if entropy is constant in the entire considered area of the flow. Shows an example of a stationary sub- sonic irrotational flow, in which the entropy has different values on different stream lines, and the pressure is not a function of density. The application of the maximum principle for subsonic flow with respect to such a flow would be unreasonable. This example shows the relevance of the question about the place of the points of maximum value of the velocity, if the entropy is not a constant. To clarify the regularities of the location of these points, was performed the analysis of the com- plete Euler equations (without any simplifying assumptions in 3-D case. The new proof of the maximum principle for sub- sonic flow was proposed. This proof does not rely on the assumption that the pressure is a function of density. Thus, it is shown that the maximum principle for subsonic flow is true for stationary subsonic irrotational flows of ideal perfect gas with variable entropy.