New biosensors for food safety screening solutions

NASA Astrophysics Data System (ADS)

Dyer, Maureen A.; Oberholtzer, Jennifer A.; Mulligan, David C.; Hanson, William P.

2009-05-01

Hanson Technologies has developed the automated OmniFresh 1000 system to sample large volumes of produce wash water, collect the pathogens, and detect their presence. By collecting a continuous sidestream of wash water, the OmniFresh uses a sample that represent the entire lot of produce being washed. The OmniFresh does not require bacterial culture or enrichment, and it detects both live and dead bacteria in the collected sample using an in-line sensor. Detection occurs in an array biosensor capable of handling large samples with complex matrices. Additionally, sample can be sent for traditional confirming tests after the screening performed by the OmniFresh.

Targeted Capture and High-Throughput Sequencing Using Molecular Inversion Probes (MIPs).

PubMed

Cantsilieris, Stuart; Stessman, Holly A; Shendure, Jay; Eichler, Evan E

2017-01-01

Molecular inversion probes (MIPs) in combination with massively parallel DNA sequencing represent a versatile, yet economical tool for targeted sequencing of genomic DNA. Several thousand genomic targets can be selectively captured using long oligonucleotides containing unique targeting arms and universal linkers. The ability to append sequencing adaptors and sample-specific barcodes allows large-scale pooling and subsequent high-throughput sequencing at relatively low cost per sample. Here, we describe a "wet bench" protocol detailing the capture and subsequent sequencing of >2000 genomic targets from 192 samples, representative of a single lane on the Illumina HiSeq 2000 platform.

Evaluation of Respondent-Driven Sampling

PubMed Central

McCreesh, Nicky; Frost, Simon; Seeley, Janet; Katongole, Joseph; Tarsh, Matilda Ndagire; Ndunguse, Richard; Jichi, Fatima; Lunel, Natasha L; Maher, Dermot; Johnston, Lisa G; Sonnenberg, Pam; Copas, Andrew J; Hayes, Richard J; White, Richard G

2012-01-01

Background Respondent-driven sampling is a novel variant of link-tracing sampling for estimating the characteristics of hard-to-reach groups, such as HIV prevalence in sex-workers. Despite its use by leading health organizations, the performance of this method in realistic situations is still largely unknown. We evaluated respondent-driven sampling by comparing estimates from a respondent-driven sampling survey with total-population data. Methods Total-population data on age, tribe, religion, socioeconomic status, sexual activity and HIV status were available on a population of 2402 male household-heads from an open cohort in rural Uganda. A respondent-driven sampling (RDS) survey was carried out in this population, employing current methods of sampling (RDS sample) and statistical inference (RDS estimates). Analyses were carried out for the full RDS sample and then repeated for the first 250 recruits (small sample). Results We recruited 927 household-heads. Full and small RDS samples were largely representative of the total population, but both samples under-represented men who were younger, of higher socioeconomic status, and with unknown sexual activity and HIV status. Respondent-driven-sampling statistical-inference methods failed to reduce these biases. Only 31%-37% (depending on method and sample size) of RDS estimates were closer to the true population proportions than the RDS sample proportions. Only 50%-74% of respondent-driven-sampling bootstrap 95% confidence intervals included the population proportion. Conclusions Respondent-driven sampling produced a generally representative sample of this well-connected non-hidden population. However, current respondent-driven-sampling inference methods failed to reduce bias when it occurred. Whether the data required to remove bias and measure precision can be collected in a respondent-driven sampling survey is unresolved. Respondent-driven sampling should be regarded as a (potentially superior) form of convenience-sampling method, and caution is required when interpreting findings based on the sampling method. PMID:22157309

Quantitative nanoscopy: Tackling sampling limitations in (S)TEM imaging of polymers and composites.

PubMed

Gnanasekaran, Karthikeyan; Snel, Roderick; de With, Gijsbertus; Friedrich, Heiner

2016-01-01

Sampling limitations in electron microscopy questions whether the analysis of a bulk material is representative, especially while analyzing hierarchical morphologies that extend over multiple length scales. We tackled this problem by automatically acquiring a large series of partially overlapping (S)TEM images with sufficient resolution, subsequently stitched together to generate a large-area map using an in-house developed acquisition toolbox (TU/e Acquisition ToolBox) and stitching module (TU/e Stitcher). In addition, we show that quantitative image analysis of the large scale maps provides representative information that can be related to the synthesis and process conditions of hierarchical materials, which moves electron microscopy analysis towards becoming a bulk characterization tool. We demonstrate the power of such an analysis by examining two different multi-phase materials that are structured over multiple length scales. Copyright © 2015 Elsevier B.V. All rights reserved.

A Comparison of Men Who Committed Different Types of Sexual Assault in a Community Sample

ERIC Educational Resources Information Center

Abbey, Antonia; Parkhill, Michele R.; Clinton-Sherrod, A. Monique; Zawacki, Tina

2007-01-01

This study extends past research by examining predictors of different types of sexual assault perpetration in a community sample. Computer-assisted self-interviews were conducted with a representative sample of 163 men in one large urban community. As hypothesized, many variables that are significant predictors of sexual assault perpetration in…

The Gap in the Subjective Wellbeing of Maori and New Zealand Europeans Widened between 2005 and 2009

ERIC Educational Resources Information Center

Sibley, Chris G.; Harre, Niki; Hoverd, William James; Houkamau, Carla A.

2011-01-01

We compared the self-reported subjective wellbeing of Maori and New Zealand (NZ) Europeans in two NZ national postal samples. The first sample was collected in 2005 before the global financial crisis of 2007/2010. The second was collected in 2009 while the crisis was ongoing. Both samples contained large and arguably representative samples of the…

A Future Moon Mission: Curatorial Statistics on Regolith Fragments Applicable to Sample Collection by Raking

NASA Technical Reports Server (NTRS)

Allton, J. H.; Bevill, T. J.

2003-01-01

The strategy of raking rock fragments from the lunar regolith as a means of acquiring representative samples has wide support due to science return, spacecraft simplicity (reliability) and economy [3, 4, 5]. While there exists widespread agreement that raking or sieving the bulk regolith is good strategy, there is lively discussion about the minimum sample size. Advocates of consor-tium studies desire fragments large enough to support petrologic and isotopic studies. Fragments from 5 to 10 mm are thought adequate [4, 5]. Yet, Jolliff et al. [6] demonstrated use of 2-4 mm fragments as repre-sentative of larger rocks. Here we make use of cura-torial records and sample catalogs to give a different perspective on minimum sample size for a robotic sample collector.

DEVELOPMENT OF A MULTIMETRIC INDEX FOR ASSESSING THE BIOLOGICAL CONDITION OF THE OHIO RIVER

EPA Science Inventory

The use of fish communities to assess environmental quality is common for streams, but a standard methodology for large rivers is largely undeveloped. We developed an index to assess the condition of fish assemblages along 1580 km of the Ohio River. Representative samples of th...

A novel method for semen collection and artificial insemination in large parrots (Psittaciformes)

PubMed Central

Lierz, Michael; Reinschmidt, Matthias; Müller, Heiner; Wink, Michael; Neumann, Daniel

2013-01-01

The paper described a novel technique for semen collection in large psittacines (patent pending), a procedure which was not routinely possible before. For the first time, a large set of semen samples is now available for analysis as well as for artificial insemination. Semen samples of more than 100 psittacine taxa were collected and analysed; data demonstrate large differences in the spermatological parameters between families, indicating an ecological relationship with breeding behaviour (polygamous versus monogamous birds). Using semen samples for artificial insemination resulted in the production of offspring in various families, such as Macaws and Cockatoos, for the first time ever. The present technique represents a breakthrough in species conservation programs and will enable future research into the ecology and environmental factors influencing endangered species. PMID:23797622

Psychometric properties of the Penn State Worry Questionnaire for children in a large clinical sample.

PubMed

Pestle, Sarah L; Chorpita, Bruce F; Schiffman, Jason

2008-04-01

The Penn State Worry Questionnaire for Children (PSWQ-C; Chorpita, Tracey, Brown, Collica, & Barlow, 1997) is a 14-item self-report measure of worry in children and adolescents. Although the PSWQ-C has demonstrated favorable psychometric properties in small clinical and large community samples, this study represents the first psychometric evaluation of the PSWQ-C in a large clinical sample (N = 491). Factor analysis indicated a two-factor structure, in contrast to all previously published findings on the measure. The PSWQ-C demonstrated favorable psychometric properties in this sample, including high internal consistency, high convergent validity with related constructs, and acceptable discriminative validity between diagnostic categories. The performance of the 3 reverse-scored items was closely examined, and results indicated retaining all 14 items.

Participation in Learning and Depressive Symptoms

ERIC Educational Resources Information Center

Jenkins, Andrew

2012-01-01

This paper reports the findings of research on relationships between depression and participation in learning using data from a large sample of older adults. The objective was to establish whether learning can reduce the risk of depression. Data were obtained from the English Longitudinal Study of Ageing, a nationally-representative sample of…

Three Conceptual Replication Studies in Group Theory

ERIC Educational Resources Information Center

Melhuish, Kathleen

2018-01-01

Many studies in mathematics education research occur with a nonrepresentative sample and are never replicated. To challenge this paradigm, I designed a large-scale study evaluating student conceptions in group theory that surveyed a national, representative sample of students. By replicating questions previously used to build theory around student…

Improvement of core drill methods

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gatz, J.L.

1975-07-01

This report documents results of a program to evaluate effectiveness of more or less conventional subsurface samplers in obtaining representative and undisturbed samples of noncohesive alluvial materials containing large quantities of gravels and cobbles. This is the first phase of a research program to improve core drill methods. Samplers evaluated consisted of the Lawrence Livermore Laboratory membrane sampler, 4-in. Denison sampler, 6-in. Dension sampler, 5-in. Modified Denison sampler, and 3-in. thinwall drive tube. Small representative samples were obtained with the Dension samplers; no undisturbed samples were obtained. The field work was accomplished in the Rhodes Canyon area, White Sands Misslemore » Range, New Mexico.« less

An efficient reliability algorithm for locating design point using the combination of importance sampling concepts and response surface method

NASA Astrophysics Data System (ADS)

Shayanfar, Mohsen Ali; Barkhordari, Mohammad Ali; Roudak, Mohammad Amin

2017-06-01

Monte Carlo simulation (MCS) is a useful tool for computation of probability of failure in reliability analysis. However, the large number of required random samples makes it time-consuming. Response surface method (RSM) is another common method in reliability analysis. Although RSM is widely used for its simplicity, it cannot be trusted in highly nonlinear problems due to its linear nature. In this paper, a new efficient algorithm, employing the combination of importance sampling, as a class of MCS, and RSM is proposed. In the proposed algorithm, analysis starts with importance sampling concepts and using a represented two-step updating rule of design point. This part finishes after a small number of samples are generated. Then RSM starts to work using Bucher experimental design, with the last design point and a represented effective length as the center point and radius of Bucher's approach, respectively. Through illustrative numerical examples, simplicity and efficiency of the proposed algorithm and the effectiveness of the represented rules are shown.

Multivariate Spatio-Temporal Clustering: A Framework for Integrating Disparate Data to Understand Network Representativeness and Scaling Up Sparse Ecosystem Measurements

NASA Astrophysics Data System (ADS)

Hoffman, F. M.; Kumar, J.; Maddalena, D. M.; Langford, Z.; Hargrove, W. W.

2014-12-01

Disparate in situ and remote sensing time series data are being collected to understand the structure and function of ecosystems and how they may be affected by climate change. However, resource and logistical constraints limit the frequency and extent of observations, particularly in the harsh environments of the arctic and the tropics, necessitating the development of a systematic sampling strategy to maximize coverage and objectively represent variability at desired scales. These regions host large areas of potentially vulnerable ecosystems that are poorly represented in Earth system models (ESMs), motivating two new field campaigns, called Next Generation Ecosystem Experiments (NGEE) for the Arctic and Tropics, funded by the U.S. Department of Energy. Multivariate Spatio-Temporal Clustering (MSTC) provides a quantitative methodology for stratifying sampling domains, informing site selection, and determining the representativeness of measurement sites and networks. We applied MSTC to down-scaled general circulation model results and data for the State of Alaska at a 4 km2 resolution to define maps of ecoregions for the present (2000-2009) and future (2090-2099), showing how combinations of 37 bioclimatic characteristics are distributed and how they may shift in the future. Optimal representative sampling locations were identified on present and future ecoregion maps, and representativeness maps for candidate sampling locations were produced. We also applied MSTC to remotely sensed LiDAR measurements and multi-spectral imagery from the WorldView-2 satellite at a resolution of about 5 m2 within the Barrow Environmental Observatory (BEO) in Alaska. At this resolution, polygonal ground features—such as centers, edges, rims, and troughs—can be distinguished. Using these remote sensing data, we up-scaled vegetation distribution data collected on these polygonal ground features to a large area of the BEO to provide distributions of plant functional types that can be used to parameterize ESMs. In addition, we applied MSTC to 4 km2 global bioclimate data to define global ecoregions and understand the representativeness of CTFS-ForestGEO, Fluxnet, and RAINFOR sampling networks. These maps identify tropical forests underrepresented in existing observations of individual and combined networks.

Effects of Sample Selection Bias on the Accuracy of Population Structure and Ancestry Inference

PubMed Central

Shringarpure, Suyash; Xing, Eric P.

2014-01-01

Population stratification is an important task in genetic analyses. It provides information about the ancestry of individuals and can be an important confounder in genome-wide association studies. Public genotyping projects have made a large number of datasets available for study. However, practical constraints dictate that of a geographical/ethnic population, only a small number of individuals are genotyped. The resulting data are a sample from the entire population. If the distribution of sample sizes is not representative of the populations being sampled, the accuracy of population stratification analyses of the data could be affected. We attempt to understand the effect of biased sampling on the accuracy of population structure analysis and individual ancestry recovery. We examined two commonly used methods for analyses of such datasets, ADMIXTURE and EIGENSOFT, and found that the accuracy of recovery of population structure is affected to a large extent by the sample used for analysis and how representative it is of the underlying populations. Using simulated data and real genotype data from cattle, we show that sample selection bias can affect the results of population structure analyses. We develop a mathematical framework for sample selection bias in models for population structure and also proposed a correction for sample selection bias using auxiliary information about the sample. We demonstrate that such a correction is effective in practice using simulated and real data. PMID:24637351

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

PubMed

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

2017-09-15

A cross-sectional study design is relatively inexpensive, fast and easy to conduct when compared to other study designs. Careful planning is essential to obtaining a representative sample of the population, and the recommended approach is to use simple random sampling from an exhaustive list of units in the target population. This approach is rarely feasible in practice, and other sampling procedures must often be adopted. For example, when slaughter pigs are the target population, sampling the pigs on the slaughter line may be an alternative to on-site sampling at a list of farms. However, it is difficult to sample a large number of farms from an exact predefined list, due to the logistics and workflow of an abattoir. Therefore, it is necessary to have a systematic sampling procedure and to evaluate the obtained sample with respect to the study objective. We propose a method for 1) planning, 2) conducting, and 3) evaluating the representativeness and reproducibility of a cross-sectional study when simple random sampling is not possible. We used an example of a cross-sectional study with the aim of quantifying the association of antimicrobial resistance and antimicrobial consumption in Danish slaughter pigs. It was not possible to visit farms within the designated timeframe. Therefore, it was decided to use convenience sampling at the abattoir. Our approach was carried out in three steps: 1) planning: using data from meat inspection to plan at which abattoirs and how many farms to sample; 2) conducting: sampling was carried out at five abattoirs; 3) evaluation: representativeness was evaluated by comparing sampled and non-sampled farms, and the reproducibility of the study was assessed through simulated sampling based on meat inspection data from the period where the actual data collection was carried out. In the cross-sectional study samples were taken from 681 Danish pig farms, during five weeks from February to March 2015. The evaluation showed that the sampling procedure was reproducible with results comparable to the collected sample. However, the sampling procedure favoured sampling of large farms. Furthermore, both under-sampled and over-sampled areas were found using scan statistics. In conclusion, sampling conducted at abattoirs can provide a spatially representative sample. Hence it is a possible cost-effective alternative to simple random sampling. However, it is important to assess the properties of the resulting sample so that any potential selection bias can be addressed when reporting the findings. Copyright © 2017 Elsevier B.V. All rights reserved.

Video Games Exposure and Sexism in a Representative Sample of Adolescents.

PubMed

Bègue, Laurent; Sarda, Elisa; Gentile, Douglas A; Bry, Clementine; Roché, Sebastian

2017-01-01

Research has indicated that many video games are saturated with stereotypes of women and that these contents may cultivate sexism. The purpose of this study was to assess the relationship between video game exposure and sexism for the first time in a large and representative sample. Our aim was also to measure the strength of this association when two other significant and well-studied sources of sexism, television exposure and religiosity, were also included in a multivariate model. A representative sample of 13520 French youth aged 11-19 years completed a survey measuring weekly video game and television exposure, religiosity, and sexist attitudes toward women. Controlling for gender and socioeconomic level, results showed that video game exposure and religiosity were both related to sexism. Implications of these results for future research on sexism in video games are discussed.

Sample allocation balancing overall representativeness and stratum precision.

PubMed

Diaz-Quijano, Fredi Alexander

2018-05-07

In large-scale surveys, it is often necessary to distribute a preset sample size among a number of strata. Researchers must make a decision between prioritizing overall representativeness or precision of stratum estimates. Hence, I evaluated different sample allocation strategies based on stratum size. The strategies evaluated herein included allocation proportional to stratum population; equal sample for all strata; and proportional to the natural logarithm, cubic root, and square root of the stratum population. This study considered the fact that, from a preset sample size, the dispersion index of stratum sampling fractions is correlated with the population estimator error and the dispersion index of stratum-specific sampling errors would measure the inequality in precision distribution. Identification of a balanced and efficient strategy was based on comparing those both dispersion indices. Balance and efficiency of the strategies changed depending on overall sample size. As the sample to be distributed increased, the most efficient allocation strategies were equal sample for each stratum; proportional to the logarithm, to the cubic root, to square root; and that proportional to the stratum population, respectively. Depending on sample size, each of the strategies evaluated could be considered in optimizing the sample to keep both overall representativeness and stratum-specific precision. Copyright © 2018 Elsevier Inc. All rights reserved.

Factors influencing stream fish recovery following a large-scale disturbance

Treesearch

William E. Ensign; Angermeier Leftwich; C. Andrew Dolloff

1997-01-01

The authors examined fish distribution and abundance in erosional habitat units in South Fork Roanoke River, VA, following a fish kill by using a reachwide sampling approach for 3 species and a representative-reach sampling approach for 10 species. Qualitative (presence-absence) and quantitative (relative abundance) estimates of distribution and abundance provided...

Generalizability of Pharmacologic and Psychotherapy Clinical Trial Results for Posttraumatic Stress Disorder to Community Samples.

PubMed

Franco, Silvia; Hoertel, Nicolas; McMahon, Kibby; Wang, Shuai; Rodríguez-Fernández, Jorge Mario; Peyre, Hugo; Limosin, Frédéric; Blanco, Carlos

2016-08-01

The present study sought to quantify the generalizability of pharmacologic and psychotherapy clinical trial results in individuals with a DSM-IV diagnosis of posttraumatic stress disorder (PTSD) to a large representative community sample. Data were derived from the 2004-2005 National Epidemiologic Survey on Alcohol and Related Conditions (NESARC), a large nationally representative sample of the adult US population. We applied a standard set of exclusion criteria representative of pharmacologic and psychotherapy clinical trials to all adults with a DSM-IV diagnosis of PTSD in the previous 12 months (n = 1,715) and then to a subsample of participants seeking treatment (n = 366). Our aim was to assess how many participants with PTSD would fulfill typical eligibility criteria. We found that more than 6 of 10 respondents from the overall PTSD sample and more than 7 of 10 respondents seeking treatment for PTSD would have been excluded by 1 exclusion criterion or more in a typical pharmacologic trial. In contrast, about 2 of 10 participants in the full sample and about 3 of 10 participants seeking treatment for PTSD would have been excluded in a typical psychotherapy efficacy trial. We found that psychotherapy trial results may be applied to most patients with PTSD in routine clinical practice. The designers of pharmacologic clinical trials should carefully consider the trade-offs between the application of each exclusion criterion and its impact on representativeness. Specification a priori of the goals of the study, better justification for each exclusion criterion, and estimation of the proportion of individuals ineligible for the trial would assist study design. Developing integrated forms of pharmacotherapy and psychotherapy that simultaneously target commonly overlapping psychiatric disorders may yield more informative results for mental health care providers and research funding agencies. © Copyright 2016 Physicians Postgraduate Press, Inc.

Psychometric Validation of the Parental Bonding Instrument in a U.K. Population-Based Sample: Role of Gender and Association With Mental Health in Mid-Late Life.

PubMed

Xu, Man K; Morin, Alexandre J S; Marsh, Herbert W; Richards, Marcus; Jones, Peter B

2016-08-01

The factorial structure of the Parental Bonding Instrument (PBI) has been frequently studied in diverse samples but no study has examined its psychometric properties from large, population-based samples. In particular, important questions have not been addressed such as the measurement invariance properties across parental and offspring gender. We evaluated the PBI based on responses from a large, representative population-based sample, using an exploratory structural equation modeling method appropriate for categorical data. Analysis revealed a three-factor structure representing "care," "overprotection," and "autonomy" parenting styles. In terms of psychometric measurement validity, our results supported the complete invariance of the PBI ratings across sons and daughters for their mothers and fathers. The PBI ratings were also robust in relation to personality and mental health status. In terms of predictive value, paternal care showed a protective effect on mental health at age 43 in sons. The PBI is a sound instrument for capturing perceived parenting styles, and is predictive of mental health in middle adulthood. © The Author(s) 2016.

The coverage of a random sample from a biological community.

PubMed

Engen, S

1975-03-01

A taxonomic group will frequently have a large number of species with small abundances. When a sample is drawn at random from this group, one is therefore faced with the problem that a large proportion of the species will not be discovered. A general definition of quantitative measures of "sample coverage" is proposed, and the problem of statistical inference is considered for two special cases, (1) the actual total relative abundance of those species that are represented in the sample, and (2) their relative contribution to the information index of diversity. The analysis is based on a extended version of the negative binomial species frequency model. The results are tabulated.

Electrofishing effort required to estimate biotic condition in southern Idaho Rivers

USGS Publications Warehouse

Maret, Terry R.; Ott, Douglas S.; Herlihy, Alan T.

2007-01-01

An important issue surrounding biomonitoring in large rivers is the minimum sampling effort required to collect an adequate number of fish for accurate and precise determinations of biotic condition. During the summer of 2002, we sampled 15 randomly selected large-river sites in southern Idaho to evaluate the effects of sampling effort on an index of biotic integrity (IBI). Boat electrofishing was used to collect sample populations of fish in river reaches representing 40 and 100 times the mean channel width (MCW; wetted channel) at base flow. Minimum sampling effort was assessed by comparing the relation between reach length sampled and change in IBI score. Thirty-two species of fish in the families Catostomidae, Centrarchidae, Cottidae, Cyprinidae, Ictaluridae, Percidae, and Salmonidae were collected. Of these, 12 alien species were collected at 80% (12 of 15) of the sample sites; alien species represented about 38% of all species (N = 32) collected during the study. A total of 60% (9 of 15) of the sample sites had poor IBI scores. A minimum reach length of about 36 times MCW was determined to be sufficient for collecting an adequate number of fish for estimating biotic condition based on an IBI score. For most sites, this equates to collecting 275 fish at a site. Results may be applicable to other semiarid, fifth-order through seventh-order rivers sampled during summer low-flow conditions.

Recruiting and retaining youth and young adults: challenges and opportunities in survey research for tobacco control.

PubMed

Cantrell, Jennifer; Hair, Elizabeth C; Smith, Alexandria; Bennett, Morgane; Rath, Jessica Miller; Thomas, Randall K; Fahimi, Mansour; Dennis, J Michael; Vallone, Donna

2018-03-01

Evaluation studies of population-based tobacco control interventions often rely on large-scale survey data from numerous respondents across many geographic areas to provide evidence of their effectiveness. Significant challenges for survey research have emerged with the evolving communications landscape, particularly for surveying hard-to-reach populations such as youth and young adults. This study combines the comprehensive coverage of an address-based sampling (ABS) frame with the timeliness of online data collection to develop a nationally representative longitudinal cohort of young people aged 15-21. We constructed an ABS frame, partially supplemented with auxiliary data, to recruit this hard-to-reach sample. Branded and tested mail-based recruitment materials were designed to bring respondents online for screening, consent and surveying. Once enrolled, respondents completed online surveys every 6 months via computer, tablet or smartphone. Numerous strategies were utilized to enhance retention and representativeness RESULTS: Results detail sample performance, representativeness and retention rates as well as device utilization trends for survey completion among youth and young adult respondents. Panel development efforts resulted in a large, nationally representative sample with high retention rates. This study is among the first to employ this hybrid ABS-to-online methodology to recruit and retain youth and young adults in a probability-based online cohort panel. The approach is particularly valuable for conducting research among younger populations as it capitalizes on their increasing access to and comfort with digital communication. We discuss challenges and opportunities of panel recruitment and retention methods in an effort to provide valuable information for tobacco control researchers seeking to obtain representative, population-based samples of youth and young adults in the U.S. as well as across the globe. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Study on Aerosol Penetration Through Clothing and Individual Protective Equipment

DTIC Science & Technology

2009-05-01

8.4X10-3 mg.m-3 (2.57X105 particles per cubic meter of air) over a 30 minute period. This scenario represents a very high end threat with a large... Isokinetic air sampling was applied and the effect of aerosol losses in sampling lines and other parts of the test rig were incorporated in analysis...eliminate any “memory” effect. The aerosol sampling (airflow direction control, start of sampling) was operated manually. Isokinetic sampling conditions

Sample Selection for Training Cascade Detectors.

PubMed

Vállez, Noelia; Deniz, Oscar; Bueno, Gloria

2015-01-01

Automatic detection systems usually require large and representative training datasets in order to obtain good detection and false positive rates. Training datasets are such that the positive set has few samples and/or the negative set should represent anything except the object of interest. In this respect, the negative set typically contains orders of magnitude more images than the positive set. However, imbalanced training databases lead to biased classifiers. In this paper, we focus our attention on a negative sample selection method to properly balance the training data for cascade detectors. The method is based on the selection of the most informative false positive samples generated in one stage to feed the next stage. The results show that the proposed cascade detector with sample selection obtains on average better partial AUC and smaller standard deviation than the other compared cascade detectors.

Evaluation of respondent-driven sampling.

PubMed

McCreesh, Nicky; Frost, Simon D W; Seeley, Janet; Katongole, Joseph; Tarsh, Matilda N; Ndunguse, Richard; Jichi, Fatima; Lunel, Natasha L; Maher, Dermot; Johnston, Lisa G; Sonnenberg, Pam; Copas, Andrew J; Hayes, Richard J; White, Richard G

2012-01-01

Respondent-driven sampling is a novel variant of link-tracing sampling for estimating the characteristics of hard-to-reach groups, such as HIV prevalence in sex workers. Despite its use by leading health organizations, the performance of this method in realistic situations is still largely unknown. We evaluated respondent-driven sampling by comparing estimates from a respondent-driven sampling survey with total population data. Total population data on age, tribe, religion, socioeconomic status, sexual activity, and HIV status were available on a population of 2402 male household heads from an open cohort in rural Uganda. A respondent-driven sampling (RDS) survey was carried out in this population, using current methods of sampling (RDS sample) and statistical inference (RDS estimates). Analyses were carried out for the full RDS sample and then repeated for the first 250 recruits (small sample). We recruited 927 household heads. Full and small RDS samples were largely representative of the total population, but both samples underrepresented men who were younger, of higher socioeconomic status, and with unknown sexual activity and HIV status. Respondent-driven sampling statistical inference methods failed to reduce these biases. Only 31%-37% (depending on method and sample size) of RDS estimates were closer to the true population proportions than the RDS sample proportions. Only 50%-74% of respondent-driven sampling bootstrap 95% confidence intervals included the population proportion. Respondent-driven sampling produced a generally representative sample of this well-connected nonhidden population. However, current respondent-driven sampling inference methods failed to reduce bias when it occurred. Whether the data required to remove bias and measure precision can be collected in a respondent-driven sampling survey is unresolved. Respondent-driven sampling should be regarded as a (potentially superior) form of convenience sampling method, and caution is required when interpreting findings based on the sampling method.

Instrumentation of sampling aircraft for measurement of launch vehicle effluents

NASA Technical Reports Server (NTRS)

Wornom, D. E.; Woods, D. C.; Thomas, M. E.; Tyson, R. W.

1977-01-01

An aircraft was selected and instrumented to measure effluents emitted from large solid propellant rockets during launch activities. The considerations involved in aircraft selection, sampling probes, and instrumentation are discussed with respect to obtaining valid airborne measurements. Discussions of the data acquisition system used, the instrument power system, and operational sampling procedures are included. Representative measurements obtained from an actual rocket launch monitoring activity are also presented.

Applying the Pseudo-Panel Approach to International Large-Scale Assessments: A Methodology for Analyzing Subpopulation Trend Data

ERIC Educational Resources Information Center

Hooper, Martin

2017-01-01

TIMSS and PIRLS assess representative samples of students at regular intervals, measuring trends in student achievement and student contexts for learning. Because individual students are not tracked over time, analysis of international large-scale assessment data is usually conducted cross-sectionally. Gustafsson (2007) proposed examining the data…

Differential Relations between Facets of Complex Problem Solving and Students' Immigration Background

ERIC Educational Resources Information Center

Sonnleitner, Philipp; Brunner, Martin; Keller, Ulrich; Martin, Romain

2014-01-01

Whereas the assessment of complex problem solving (CPS) has received increasing attention in the context of international large-scale assessments, its fairness in regard to students' cultural background has gone largely unexplored. On the basis of a student sample of 9th-graders (N = 299), including a representative number of immigrant students (N…

Phase II test plan for the evaluation of the performance of container filling systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

BOGER, R.M.

The PHMC will provide tank wastes for final treatment by BNFL from Hanford's waste tanks. Concerns about the ability for ''grab'' sampling to provide large volumes of representative waste samples has led to the development of a nested, fixed-depth sampling system. Preferred concepts for filling sample containers that meet RCRA organic sample criteria were identified by a PHMC Decision Board. These systems will replace the needle based sampling ''T'' that is currently on the sampling system. This test plan document identifies cold tests with simulants that will demonstrate the preferred bottle filling concepts abilities to provide representative waste samples andmore » will meet RCRA criteria. Additional tests are identified that evaluate the potential for cross-contamination between samples and the ability for the system to decontaminate surfaces which have contacted tank wastes. These tests will be performed with kaolid/water and sand/water slurry simulants in the test rig that was used by AEAT to complete Phase 1 tests in FY 1999.« less

Back to Africa: Tracing Dyslexia Genes in East Africa

ERIC Educational Resources Information Center

Grigorenko, Elena L.; Naples, Adam; Chang, Joseph; Romano, Christina; Ngorosho, Damaris; Kungulilo, Selemani; Jukes, Matthew; Bundy, Donald

2007-01-01

A sample of Swahili-speaking probands with reading difficulties was identified from a large representative sample of 1,500 school children in the rural areas of Tanzania. Families of these probands (n = 88) were invited to participate in the study. The proband and his/her siblings received a battery of reading-related tasks and performance on…

Gender Differences in Achievement in a Large, Nationally Representative Sample of Children and Adolescents

ERIC Educational Resources Information Center

Scheiber, Caroline; Reynolds, Matthew R.; Hajovsky, Daniel B.; Kaufman, Alan S.

2015-01-01

The purpose of this study was to investigate developmental gender differences in academic achievement areas, with the primary focus on writing, using the child and adolescent portion (ages 6-21 years) of the "Kaufman Test of Educational Achievement-Second Edition, Brief Form," norming sample (N = 1,574). Path analytic models with gender,…

Video Games Exposure and Sexism in a Representative Sample of Adolescents

PubMed Central

Bègue, Laurent; Sarda, Elisa; Gentile, Douglas A.; Bry, Clementine; Roché, Sebastian

2017-01-01

Research has indicated that many video games are saturated with stereotypes of women and that these contents may cultivate sexism. The purpose of this study was to assess the relationship between video game exposure and sexism for the first time in a large and representative sample. Our aim was also to measure the strength of this association when two other significant and well-studied sources of sexism, television exposure and religiosity, were also included in a multivariate model. A representative sample of 13520 French youth aged 11–19 years completed a survey measuring weekly video game and television exposure, religiosity, and sexist attitudes toward women. Controlling for gender and socioeconomic level, results showed that video game exposure and religiosity were both related to sexism. Implications of these results for future research on sexism in video games are discussed. PMID:28408891

Bayesian geostatistics in health cartography: the perspective of malaria.

PubMed

Patil, Anand P; Gething, Peter W; Piel, Frédéric B; Hay, Simon I

2011-06-01

Maps of parasite prevalences and other aspects of infectious diseases that vary in space are widely used in parasitology. However, spatial parasitological datasets rarely, if ever, have sufficient coverage to allow exact determination of such maps. Bayesian geostatistics (BG) is a method for finding a large sample of maps that can explain a dataset, in which maps that do a better job of explaining the data are more likely to be represented. This sample represents the knowledge that the analyst has gained from the data about the unknown true map. BG provides a conceptually simple way to convert these samples to predictions of features of the unknown map, for example regional averages. These predictions account for each map in the sample, yielding an appropriate level of predictive precision.

Bayesian geostatistics in health cartography: the perspective of malaria

PubMed Central

Patil, Anand P.; Gething, Peter W.; Piel, Frédéric B.; Hay, Simon I.

2011-01-01

Maps of parasite prevalences and other aspects of infectious diseases that vary in space are widely used in parasitology. However, spatial parasitological datasets rarely, if ever, have sufficient coverage to allow exact determination of such maps. Bayesian geostatistics (BG) is a method for finding a large sample of maps that can explain a dataset, in which maps that do a better job of explaining the data are more likely to be represented. This sample represents the knowledge that the analyst has gained from the data about the unknown true map. BG provides a conceptually simple way to convert these samples to predictions of features of the unknown map, for example regional averages. These predictions account for each map in the sample, yielding an appropriate level of predictive precision. PMID:21420361

Validation of the Narcissistic Admiration and Rivalry Questionnaire Short Scale (NARQ-S) in convenience and representative samples.

PubMed

Leckelt, Marius; Wetzel, Eunike; Gerlach, Tanja M; Ackerman, Robert A; Miller, Joshua D; Chopik, William J; Penke, Lars; Geukes, Katharina; Küfner, Albrecht C P; Hutteman, Roos; Richter, David; Renner, Karl-Heinz; Allroggen, Marc; Brecheen, Courtney; Campbell, W Keith; Grossmann, Igor; Back, Mitja D

2018-01-01

Due to increased empirical interest in narcissism across the social sciences, there is a need for inventories that can be administered quickly while also reliably measuring both the agentic and antagonistic aspects of grandiose narcissism. In this study, we sought to validate the factor structure, provide representative descriptive data and reliability estimates, assess the reliability across the trait spectrum, and examine the nomological network of the short version of the Narcissistic Admiration and Rivalry Questionnaire (NARQ-S; Back et al., 2013). We used data from a large convenience sample (total N = 11,937) as well as data from a large representative sample (total N = 4,433) that included responses to other narcissism measures as well as related constructs, including the other Dark Triad traits, Big Five personality traits, and self-esteem. Confirmatory factor analysis and item response theory were used to validate the factor structure and estimate the reliability across the latent trait spectrum, respectively. Results suggest that the NARQ-S shows a robust factor structure and is a reliable and valid short measure of the agentic and antagonistic aspects of grandiose narcissism. We also discuss future directions and applications of the NARQ-S as a short and comprehensive measure of grandiose narcissism. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Attrition in a Large Scale Longitudinal Study of the Elderly: The Role of Health-Status Variables.

ERIC Educational Resources Information Center

Horgas, Ann L.; And Others

In a longitudinal study, subject attrition constitutes a potential threat to the usefulness of data collected from subjects remaining in later waves of the study. If attrition is selective, then the sample at later waves of the study may be representative of a different population than that represented at the outset of the study. This study…

Apollo 15 coarse fines (4-10 mm): Sample classification, description and inventory

NASA Technical Reports Server (NTRS)

Powell, B. N.

1972-01-01

A particle by particle binocular microscopic examination of all of the Apollo 15 4-10 mm fines samples is reported. These particles are classified according to their macroscopic lithologic features in order to provide a basis for sample allocations and future study. The relatively large size of these particles renders them too vaulable to permit treatment along with the other bulk fines, yet they are too small (and numerous) to practically receive full individual descriptive treatment as given the larger rock samples. This examination, classification and description of subgroups represents a compromise treatment. In most cases and for many types of investigation the individual particles should be large enough to permit the application of more than one type of analysis.

A workforce survey of Australian chiropractic: the profile and practice features of a nationally representative sample of 2,005 chiropractors.

PubMed

Adams, Jon; Lauche, Romy; Peng, Wenbo; Steel, Amie; Moore, Craig; Amorin-Woods, Lyndon G; Sibbritt, David

2017-01-05

This paper reports the profile of the Australian chiropractic workforce and characteristics of chiropractic care from a large nationally-representative sample of practitioners. A 21-item questionnaire examining practitioner, practice and clinical management characteristics was distributed to all registered chiropractors (n = 4,684) in Australia in 2015 via both online and hard copy mail out. The survey attracted a response rate of 43% (n = 2,005), and the sample is largely representative of the national chiropractic workforce on a number of key indicators. The average age of the chiropractors was 42.1 years, nearly two-thirds are male, and the vast majority hold a bachelor degree or higher qualification. Australian chiropractors are focused upon treating people across a wide age range who mainly present with musculoskeletal conditions. Australian chiropractors have referral relationships with a range of conventional, allied health and complementary medicine (CAM) providers. The chiropractic profession represents a substantial component of the contemporary Australian health care system with chiropractors managing an estimated 21.3 million patient visits per year. While the Australian chiropractic workforce is well educated, research engagement and research capacity remains sub-optimal and there is much room for further capacity building to help chiropractic reach full potential as a key integrated profession within an evidence-based health care system. Further rich, in-depth research is warranted to improve our understanding of the role of chiropractic within the Australian health care system.

Data processing 1: Advancements in machine analysis of multispectral data

NASA Technical Reports Server (NTRS)

Swain, P. H.

1972-01-01

Multispectral data processing procedures are outlined beginning with the data display process used to accomplish data editing and proceeding through clustering, feature selection criterion for error probability estimation, and sample clustering and sample classification. The effective utilization of large quantities of remote sensing data by formulating a three stage sampling model for evaluation of crop acreage estimates represents an improvement in determining the cost benefit relationship associated with remote sensing technology.

Physical and chemical characterization of representative samples of recycled rubber from end-of-life tires.

PubMed

Re Depaolini, Andrea; Bianchi, Giancarlo; Fornai, Daniele; Cardelli, Angela; Badalassi, Marco; Cardelli, Camillo; Davoli, Enrico

2017-10-01

A large number of end-of-life tires (ELTs) were sampled and classified by type, age and origin to obtain recycled rubber samples representative of the materials placed on the Italian market. The selected recycled tire rubber samples were physically and chemically characterized and a chemometric approach was used to determine correlations. The polycyclic aromatic hydrocarbons (PAHs) content was correlated to the aromaticity index and a model was built to establish the H-Bay aromaticity index (H-Bay) from the PAH concentrations. ELT of different origin and age produced in non-European countries generally had higher PAH content and a higher H-Bay index. H-Bay values of all the samples were lower than the REACH limits and old tires had higher aromatic content than recent ones, possibly due to the replacement of aromatic oils in tire production. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Recruitment of representative samples for low incidence cancer populations: Do registries deliver?

PubMed Central

2011-01-01

Background Recruiting large and representative samples of adolescent and young adult (AYA) cancer survivors is important for gaining accurate data regarding the prevalence of unmet needs in this population. This study aimed to describe recruitment rates for AYAs recruited through a cancer registry with particular focus on: active clinician consent protocols, reasons for clinicians not providing consent and the representativeness of the final sample. Methods Adolescents and young adults aged 14 to19 years inclusive and listed on the cancer registry from January 1 2002 to December 31 2007 were identified. An active clinician consent protocol was used whereby the registry sent a letter to AYAs primary treating clinicians requesting permission to contact the survivors. The registry then sent survivors who received their clinician's consent a letter seeking permission to forward their contact details to the research team. Consenting AYAs were sent a questionnaire which assessed their unmet needs. Results The overall consent rate for AYAs identified as eligible by the registry was 7.8%. Of the 411 potentially eligible survivors identified, just over half (n = 232, 56%) received their clinician's consent to be contacted. Of those 232 AYAs, 65% were unable to be contacted. Only 18 AYAs (7.8%) refused permission for their contact details to be passed on to the research team. Of the 64 young people who agreed to be contacted, 50% (n = 32) completed the questionnaire. Conclusions Cancer registries which employ active clinician consent protocols may not be appropriate for recruiting large, representative samples of AYAs diagnosed with cancer. Given that AYA cancer survivors are highly mobile, alternative methods such as treatment centre and clinic based recruitment may need to be considered. PMID:21235819

Cognitive and Academic Abilities Associated with Symptoms of Attention-Deficit/Hyperactivity Disorder: A Comparison between Subtypes in a Greek Non-Clinical Sample

ERIC Educational Resources Information Center

Papaioannou, Sophia; Mouzaki, Angeliki; Sideridis, Georgios D.; Antoniou, Foteini; Padeliadu, Suzanna; Simos, Panagiotis G.

2016-01-01

The study assessed cognitive and academic performance of children demonstrating teacher-rated ADHD-related symptoms (Inattention [IA] and/or Hyperactivity/Impulsivity [H/I]) in a representative sample of, largely untreated, Greek elementary school students (N?=?923). A battery of tests assessing short-term memory (STM), sustained attention,…

Status Variations in Alcohol Use among Young Adults: Results from the 1984 National Longitudinal Surveys of Youth.

ERIC Educational Resources Information Center

Crowley, Joan E.

This document gives descriptive results on alcohol use patterns among young adults from the 1984 National Longitudinal Survey of Labor Market of Youth, a survey of a large, nationally representative sample supplemented by samples of blacks, Hispanics, and economically disadvantaged non-black, non-Hispanic youth and covering the entire range of…

Datasets for Ostrava PMF paper

EPA Pesticide Factsheets

These data support a published journal paper described as follows:A 14-week investigation during a warm and cold seasons was conducted to improve understanding of airpollution sources that might be impacting air quality in Ostrava, the Czech Republic. Fine particulatematter (PM2.5) samples were collected in consecutive 12-h day and night increments during spring andfall 2012 sampling campaigns. Sampling sites were strategically located to evaluate conditions in closeproximity of a large steel works industrial complex, as well as away from direct influence of theindustrial complex. These samples were analyzed for metals and other elements, organic and elemental(black) carbon, and polycyclic aromatic hydrocarbons (PAHs). The PM2.5 samples were supplementedwith pollutant gases and meteorological parameters. We applied the EPA PMF v5.1 model with uncertainty estimate features to the Ostrava data set. Using the model's bootstrapping procedure and other considerations, six factors were determined to provide the optimum solution. Each model run consisted of 100 iterations to ensure that the solution represents a global minimum. The resulting factors were identified as representing coal (power plants), mixed Cl, crustal, industrial 1 (alkali metals and PAHs), industrial 2 (transition metals), and home heat/transportation. The home heating source is thought to be largely domestic boilers burning low quality fuels such as lignite, wood, and domestic waste.Transportation-r

Large landslides from oceanic volcanoes

USGS Publications Warehouse

Holcomb, R.T.; Searle, R.C.

1991-01-01

Large landslides are ubiquitous around the submarine flanks of Hawaiian volcanoes, and GLORIA has also revealed large landslides offshore from Tristan da Cunha and El Hierro. On both of the latter islands, steep flanks formerly attributed to tilting or marine erosion have been reinterpreted as landslide headwalls mantled by younger lava flows. These landslides occur in a wide range of settings and probably represent only a small sample from a large population. They may explain the large volumes of archipelagic aprons and the stellate shapes of many oceanic volcanoes. Large landslides and associated tsunamis pose hazards to many islands. -from Authors

Estimating the probability that the sample mean is within a desired fraction of the standard deviation of the true mean.

PubMed

Schillaci, Michael A; Schillaci, Mario E

2009-02-01

The use of small sample sizes in human and primate evolutionary research is commonplace. Estimating how well small samples represent the underlying population, however, is not commonplace. Because the accuracy of determinations of taxonomy, phylogeny, and evolutionary process are dependant upon how well the study sample represents the population of interest, characterizing the uncertainty, or potential error, associated with analyses of small sample sizes is essential. We present a method for estimating the probability that the sample mean is within a desired fraction of the standard deviation of the true mean using small (n<10) or very small (n < or = 5) sample sizes. This method can be used by researchers to determine post hoc the probability that their sample is a meaningful approximation of the population parameter. We tested the method using a large craniometric data set commonly used by researchers in the field. Given our results, we suggest that sample estimates of the population mean can be reasonable and meaningful even when based on small, and perhaps even very small, sample sizes.

Unique risk and protective factors for partner aggression in a large scale air force survey.

PubMed

Slep, Amy M Smith; Foran, Heather M; Heyman, Richard E; Snarr, Jeffery D

2010-08-01

The objective of this study is to examine risk factors of physical aggression against a partner in a large representative Active Duty Air Force sample. A stratified sample of 128,950 United States Active Duty members were invited to participate in an Air Force-wide anonymous online survey across 82 bases. The final sample (N = 52,780) was weighted to be representative of the United States Air Force. Backward stepwise regression analyses were conducted to identify unique predictors of partner physical aggression perpetration within and across different ecological levels (individual, family, organization, and community levels). Relationship satisfaction, alcohol problems, financial stress, and number of years in the military were identified as unique predictors of men's and women's perpetration of violence against their partner across ecological levels. Parental status, support from neighbors, personal coping, and support from formal agencies also uniquely predicted men's but not women's perpetration of violence across ecological levels. This study identified specific risk factors of partner violence that may be targeted by prevention and intervention efforts aimed at different levels of impact (e.g., family interventions, community-wide programs).

A Radio-Map Automatic Construction Algorithm Based on Crowdsourcing

PubMed Central

Yu, Ning; Xiao, Chenxian; Wu, Yinfeng; Feng, Renjian

2016-01-01

Traditional radio-map-based localization methods need to sample a large number of location fingerprints offline, which requires huge amount of human and material resources. To solve the high sampling cost problem, an automatic radio-map construction algorithm based on crowdsourcing is proposed. The algorithm employs the crowd-sourced information provided by a large number of users when they are walking in the buildings as the source of location fingerprint data. Through the variation characteristics of users’ smartphone sensors, the indoor anchors (doors) are identified and their locations are regarded as reference positions of the whole radio-map. The AP-Cluster method is used to cluster the crowdsourced fingerprints to acquire the representative fingerprints. According to the reference positions and the similarity between fingerprints, the representative fingerprints are linked to their corresponding physical locations and the radio-map is generated. Experimental results demonstrate that the proposed algorithm reduces the cost of fingerprint sampling and radio-map construction and guarantees the localization accuracy. The proposed method does not require users’ explicit participation, which effectively solves the resource-consumption problem when a location fingerprint database is established. PMID:27070623

[Water and suspended matter sampling in fresh water networks].

PubMed

Galas, Chiara; Stellato, Luisa; Barbizzi, Sabrina; Belli, Maria; Sansone, Umberto

2005-01-01

Metals and radionuclides in water systems can be easily adsorbed on suspended matter and, finally, they could eventually accumulate in the aquatic environment. The assessment of the health of a water body needs also sampling of the suspended matter fraction. In this paper sampling systems to characterise contaminants associated with the suspended matter fraction are described, with a particular attention to the collection and preservation of samples. Sampling must be representative, to obtain reliable conclusions. In this context it is stressed the importance of the evaluation of the sampling uncertainty, which contributes to a large extent to the total uncertainty.

Evaluation of the NCPDP Structured and Codified Sig Format for e-prescriptions.

PubMed

Liu, Hangsheng; Burkhart, Q; Bell, Douglas S

2011-01-01

To evaluate the ability of the structure and code sets specified in the National Council for Prescription Drug Programs Structured and Codified Sig Format to represent ambulatory electronic prescriptions. We parsed the Sig strings from a sample of 20,161 de-identified ambulatory e-prescriptions into variables representing the fields of the Structured and Codified Sig Format. A stratified random sample of these representations was then reviewed by a group of experts. For codified Sig fields, we attempted to map the actual words used by prescribers to the equivalent terms in the designated terminology. Proportion of prescriptions that the Format could fully represent; proportion of terms used that could be mapped to the designated terminology. The fields defined in the Format could fully represent 95% of Sigs (95% CI 93% to 97%), but ambiguities were identified, particularly in representing multiple-step instructions. The terms used by prescribers could be codified for only 60% of dose delivery methods, 84% of dose forms, 82% of vehicles, 95% of routes, 70% of sites, 33% of administration timings, and 93% of indications. The findings are based on a retrospective sample of ambulatory prescriptions derived mostly from primary care physicians. The fields defined in the Format could represent most of the patient instructions in a large prescription sample, but prior to its mandatory adoption, further work is needed to ensure that potential ambiguities are addressed and that a complete set of terms is available for the codified fields.

The Demographics of Alcohol Use among Young Americans: Results from the 1983 National Longitudinal Survey of Labor Market Experience of Youth.

ERIC Educational Resources Information Center

Crowley, Joan E.

This document gives results of research on alcohol use by young Americans from the 1983 National Longitudinal Survey of Labor Market Experience of Youth, a survey of a large, nationally representative sample supplemented by samples of blacks, Hispanics, and economically disadvantaged non-black, non-Hispanic youth and covering the entire range of…

A post-mortem survey on end-of-life decisions using a representative sample of death certificates in Flanders, Belgium: research protocol

PubMed Central

Chambaere, Kenneth; Bilsen, Johan; Cohen, Joachim; Pousset, Geert; Onwuteaka-Philipsen, Bregje; Mortier, Freddy; Deliens, Luc

2008-01-01

Background Reliable studies of the incidence and characteristics of medical end-of-life decisions with a certain or possible life shortening effect (ELDs) are indispensable for an evidence-based medical and societal debate on this issue. This article presents the protocol drafted for the 2007 ELD Study in Flanders, Belgium, and outlines how the main aims and challenges of the study (i.e. making reliable incidence estimates of end-of-life decisions, even rare ones, and describing their characteristics; allowing comparability with past ELD studies; guaranteeing strict anonymity given the sensitive nature of the research topic; and attaining a sufficient response rate) are addressed in a post-mortem survey using a representative sample of death certificates. Study design Reliable incidence estimates are achievable by using large at random samples of death certificates of deceased persons in Flanders (aged one year or older). This entails the cooperation of the appropriate administrative authorities. To further ensure the reliability of the estimates and descriptions, especially of less prevalent end-of-life decisions (e.g. euthanasia), a stratified sample is drawn. A questionnaire is sent out to the certifying physician of each death sampled. The questionnaire, tested thoroughly and avoiding emotionally charged terms is based largely on questions that have been validated in previous national and European ELD studies. Anonymity of both patient and physician is guaranteed through a rigorous procedure, involving a lawyer as intermediary between responding physicians and researchers. To increase response we follow the Total Design Method (TDM) with a maximum of three follow-up mailings. Also, a non-response survey is conducted to gain insight into the reasons for lack of response. Discussion The protocol of the 2007 ELD Study in Flanders, Belgium, is appropriate for achieving the objectives of the study; as past studies in Belgium, the Netherlands, and other European countries have shown, strictly anonymous and thorough surveys among physicians using a large, stratified, and representative death certificate sample are most suitable in nationwide studies of incidence and characteristics of end-of-life decisions. There are however also some limitations to the study design. PMID:18752659

Measuring Teaching Quality in Several European Countries

ERIC Educational Resources Information Center

van de Grift, Wim J. C. M.

2014-01-01

Teaching quality has been observed in large representative samples from Flanders (Belgium), Lower Saxony (Germany), the Slovak Republic, and The Netherlands. This study reveals that measures of "creating a safe and stimulating climate", "clear and activating instruction", and "teaching learning strategies" were…

The second Southern African Bird Atlas Project: Causes and consequences of geographical sampling bias.

PubMed

Hugo, Sanet; Altwegg, Res

2017-09-01

Using the Southern African Bird Atlas Project (SABAP2) as a case study, we examine the possible determinants of spatial bias in volunteer sampling effort and how well such biased data represent environmental gradients across the area covered by the atlas. For each province in South Africa, we used generalized linear mixed models to determine the combination of variables that explain spatial variation in sampling effort (number of visits per 5' × 5' grid cell, or "pentad"). The explanatory variables were distance to major road and exceptional birding locations or "sampling hubs," percentage cover of protected, urban, and cultivated area, and the climate variables mean annual precipitation, winter temperatures, and summer temperatures. Further, we used the climate variables and plant biomes to define subsets of pentads representing environmental zones across South Africa, Lesotho, and Swaziland. For each environmental zone, we quantified sampling intensity, and we assessed sampling completeness with species accumulation curves fitted to the asymptotic Lomolino model. Sampling effort was highest close to sampling hubs, major roads, urban areas, and protected areas. Cultivated area and the climate variables were less important. Further, environmental zones were not evenly represented by current data and the zones varied in the amount of sampling required representing the species that are present. SABAP2 volunteers' preferences in birding locations cause spatial bias in the dataset that should be taken into account when analyzing these data. Large parts of South Africa remain underrepresented, which may restrict the kind of ecological questions that may be addressed. However, sampling bias may be improved by directing volunteers toward undersampled regions while taking into account volunteer preferences.

Problematic Social Media Use: Results from a Large-Scale Nationally Representative Adolescent Sample

PubMed Central

Bányai, Fanni; Zsila, Ágnes; Király, Orsolya; Maraz, Aniko; Elekes, Zsuzsanna; Griffiths, Mark D.; Andreassen, Cecilie Schou

2017-01-01

Despite social media use being one of the most popular activities among adolescents, prevalence estimates among teenage samples of social media (problematic) use are lacking in the field. The present study surveyed a nationally representative Hungarian sample comprising 5,961 adolescents as part of the European School Survey Project on Alcohol and Other Drugs (ESPAD). Using the Bergen Social Media Addiction Scale (BSMAS) and based on latent profile analysis, 4.5% of the adolescents belonged to the at-risk group, and reported low self-esteem, high level of depression symptoms, and elevated social media use. Results also demonstrated that BSMAS has appropriate psychometric properties. It is concluded that adolescents at-risk of problematic social media use should be targeted by school-based prevention and intervention programs. PMID:28068404

Problematic Social Media Use: Results from a Large-Scale Nationally Representative Adolescent Sample.

PubMed

Bányai, Fanni; Zsila, Ágnes; Király, Orsolya; Maraz, Aniko; Elekes, Zsuzsanna; Griffiths, Mark D; Andreassen, Cecilie Schou; Demetrovics, Zsolt

2017-01-01

Despite social media use being one of the most popular activities among adolescents, prevalence estimates among teenage samples of social media (problematic) use are lacking in the field. The present study surveyed a nationally representative Hungarian sample comprising 5,961 adolescents as part of the European School Survey Project on Alcohol and Other Drugs (ESPAD). Using the Bergen Social Media Addiction Scale (BSMAS) and based on latent profile analysis, 4.5% of the adolescents belonged to the at-risk group, and reported low self-esteem, high level of depression symptoms, and elevated social media use. Results also demonstrated that BSMAS has appropriate psychometric properties. It is concluded that adolescents at-risk of problematic social media use should be targeted by school-based prevention and intervention programs.

Chemical concentrations in water and suspended sediment, Green River to Lower Duwamish Waterway near Seattle, Washington, 2016–17

USGS Publications Warehouse

Conn, Kathleen E.; Black, Robert W.; Peterson, Norman T.; Senter, Craig A.; Chapman, Elena A.

2018-01-05

From August 2016 to March 2017, the U.S. Geological Survey (USGS) collected representative samples of filtered and unfiltered water and suspended sediment (including the colloidal fraction) at USGS streamgage 12113390 (Duwamish River at Golf Course, at Tukwila, Washington) during 13 periods of differing flow conditions. Samples were analyzed by Washington-State-accredited laboratories for a large suite of compounds, including metals, dioxins/furans, semivolatile compounds including polycyclic aromatic hydrocarbons, butyltins, the 209 polychlorinated biphenyl (PCB) congeners, and total and dissolved organic carbon. Concurrent with the chemistry sampling, water-quality field parameters were measured, and representative water samples were collected and analyzed for river suspended-sediment concentration and particle-size distribution. The results provide new data that can be used to estimate sediment and chemical loads transported by the Green River to the Lower Duwamish Waterway.

Flexible sampling large-scale social networks by self-adjustable random walk

NASA Astrophysics Data System (ADS)

Xu, Xiao-Ke; Zhu, Jonathan J. H.

2016-12-01

Online social networks (OSNs) have become an increasingly attractive gold mine for academic and commercial researchers. However, research on OSNs faces a number of difficult challenges. One bottleneck lies in the massive quantity and often unavailability of OSN population data. Sampling perhaps becomes the only feasible solution to the problems. How to draw samples that can represent the underlying OSNs has remained a formidable task because of a number of conceptual and methodological reasons. Especially, most of the empirically-driven studies on network sampling are confined to simulated data or sub-graph data, which are fundamentally different from real and complete-graph OSNs. In the current study, we propose a flexible sampling method, called Self-Adjustable Random Walk (SARW), and test it against with the population data of a real large-scale OSN. We evaluate the strengths of the sampling method in comparison with four prevailing methods, including uniform, breadth-first search (BFS), random walk (RW), and revised RW (i.e., MHRW) sampling. We try to mix both induced-edge and external-edge information of sampled nodes together in the same sampling process. Our results show that the SARW sampling method has been able to generate unbiased samples of OSNs with maximal precision and minimal cost. The study is helpful for the practice of OSN research by providing a highly needed sampling tools, for the methodological development of large-scale network sampling by comparative evaluations of existing sampling methods, and for the theoretical understanding of human networks by highlighting discrepancies and contradictions between existing knowledge/assumptions of large-scale real OSN data.

Feline mitochondrial DNA sampling for forensic analysis: when enough is enough!

PubMed

Grahn, Robert A; Alhaddad, Hasan; Alves, Paulo C; Randi, Ettore; Waly, Nashwa E; Lyons, Leslie A

2015-05-01

Pet hair has a demonstrated value in resolving legal issues. Cat hair is chronically shed and it is difficult to leave a home with cats without some level of secondary transfer. The power of cat hair as an evidentiary resource may be underused because representative genetic databases are not available for exclusionary purposes. Mitochondrial control region databases are highly valuable for hair analyses and have been developed for the cat. In a representative worldwide data set, 83% of domestic cat mitotypes belong to one of twelve major types. Of the remaining 17%, 7.5% are unique within the published 1394 sample database. The current research evaluates the sample size necessary to establish a representative population for forensic comparison of the mitochondrial control region for the domestic cat. For most worldwide populations, randomly sampling 50 unrelated local individuals will achieve saturation at 95%. The 99% saturation is achieved by randomly sampling 60-170 cats, depending on the numbers of mitotypes available in the population at large. Likely due to the recent domestication of the cat and minimal localized population substructure, fewer cats are needed to meet mitochondria DNA control region database practical saturation than for humans or dogs. Coupled with the available worldwide feline control region database of nearly 1400 cats, minimal local sampling will be required to establish an appropriate comparative representative database and achieve significant exclusionary power. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Detection of triazole deicing additives in soil samples from airports with low, mid, and large volume aircraft deicing activities.

PubMed

McNeill, K S; Cancilla, D A

2009-03-01

Soil samples from three USA airports representing low, mid, and large volume users of aircraft deicing fluids (ADAFs) were analyzed by LC/MS/MS for the presence of triazoles, a class of corrosion inhibitors historically used in ADAFs. Triazoles, specifically the 4-methyl-1H-benzotriazole and the 5-methyl-1H-benzotriazole, were detected in a majority of samples and ranged from 2.35 to 424.19 microg/kg. Previous studies have focused primarily on ground and surface water impacts of larger volume ADAF users. The detection of triazoles in soils at low volume ADAF use airports suggests that deicing activities may have a broader environmental impact than previously considered.

Neutron Tomography at the Los Alamos Neutron Science Center

DOE Office of Scientific and Technical Information (OSTI.GOV)

Myers, William Riley

Neutron imaging is an incredibly powerful tool for non-destructive sample characterization and materials science. Neutron tomography is one technique that results in a three-dimensional model of the sample, representing the interaction of the neutrons with the sample. This relies both on reliable data acquisition and on image processing after acquisition. Over the course of the project, the focus has changed from the former to the latter, culminating in a large-scale reconstruction of a meter-long fossilized skull. The full reconstruction is not yet complete, though tools have been developed to improve the speed and accuracy of the reconstruction. This project helpsmore » to improve the capabilities of LANSCE and LANL with regards to imaging large or unwieldy objects.« less

Whale sharks target dense prey patches of sergestid shrimp off Tanzania

PubMed Central

Rohner, Christoph A.; Armstrong, Amelia J.; Pierce, Simon J.; Prebble, Clare E. M.; Cagua, E. Fernando; Cochran, Jesse E. M.; Berumen, Michael L.; Richardson, Anthony J.

2015-01-01

Large planktivores require high-density prey patches to make feeding energetically viable. This is a major challenge for species living in tropical and subtropical seas, such as whale sharks Rhincodon typus. Here, we characterize zooplankton biomass, size structure and taxonomic composition from whale shark feeding events and background samples at Mafia Island, Tanzania. The majority of whale sharks were feeding (73%, 380 of 524 observations), with the most common behaviour being active surface feeding (87%). We used 20 samples collected from immediately adjacent to feeding sharks and an additional 202 background samples for comparison to show that plankton biomass was ∼10 times higher in patches where whale sharks were feeding (25 vs. 2.6 mg m−3). Taxonomic analyses of samples showed that the large sergestid Lucifer hanseni (∼10 mm) dominated while sharks were feeding, accounting for ∼50% of identified items, while copepods (<2 mm) dominated background samples. The size structure was skewed towards larger animals representative of L.hanseni in feeding samples. Thus, whale sharks at Mafia Island target patches of dense, large, zooplankton dominated by sergestids. Large planktivores, such as whale sharks, which generally inhabit warm oligotrophic waters, aggregate in areas where they can feed on dense prey to obtain sufficient energy. PMID:25814777

Evaluation of residual uranium contamination in the dirt floor of an abandoned metal rolling mill.

PubMed

Glassford, Eric; Spitz, Henry; Lobaugh, Megan; Spitler, Grant; Succop, Paul; Rice, Carol

2013-02-01

A single, large, bulk sample of uranium-contaminated material from the dirt floor of an abandoned metal rolling mill was separated into different types and sizes of aliquots to simulate samples that would be collected during site remediation. The facility rolled approximately 11,000 tons of hot-forged ingots of uranium metal approximately 60 y ago, and it has not been used since that time. Thirty small mass (≈ 0.7 g) and 15 large mass (≈ 70 g) samples were prepared from the heterogeneously contaminated bulk material to determine how measurements of the uranium contamination vary with sample size. Aliquots of bulk material were also resuspended in an exposure chamber to produce six samples of respirable particles that were obtained using a cascade impactor. Samples of removable surface contamination were collected by wiping 100 cm of the interior surfaces of the exposure chamber with 47-mm-diameter fiber filters. Uranium contamination in each of the samples was measured directly using high-resolution gamma ray spectrometry. As expected, results for isotopic uranium (i.e., U and U) measured with the large-mass and small-mass samples are significantly different (p < 0.001), and the coefficient of variation (COV) for the small-mass samples was greater than for the large-mass samples. The uranium isotopic concentrations measured in the air and on the wipe samples were not significantly different and were also not significantly different (p > 0.05) from results for the large- or small-mass samples. Large-mass samples are more reliable for characterizing heterogeneously distributed radiological contamination than small-mass samples since they exhibit the least variation compared to the mean. Thus, samples should be sufficiently large in mass to insure that the results are truly representative of the heterogeneously distributed uranium contamination present at the facility. Monitoring exposure of workers and the public as a result of uranium contamination resuspended during site remediation should be evaluated using samples of sufficient size and type to accommodate the heterogeneous distribution of uranium in the bulk material.

A National Study of Autistic Symptoms in the General Population of School-Age Children and Those Diagnosed with Autism Spectrum Disorders

ERIC Educational Resources Information Center

Goldstein, Sam; Naglieri, Jack A.; Rzepa, Sara; Williams, Kevin M.

2012-01-01

We examined the interrelationships among symptoms related to autism spectrum disorders (ASD) using a large representative sample and clinical groups of children aged 6 to 11 and youth aged 12 to 18 years rated by parents (N = 1,881) or teachers (N = 2,171). The samples included individuals from the United States and Canada from the standardization…

Three periods of one and a half decade of ischemic stroke susceptibility gene research: lessons we have learned

PubMed Central

2010-01-01

Candidate gene association studies, linkage studies and genome-wide association studies have highlighted the role of genetic factors in the development of ischemic stroke. This research started over a decade ago, and can be separated into three major periods of research. In the first wave classic susceptibility markers associated with other diseases (such as the Leiden mutation in Factor V and mutations in the prothrombin and 5,10-methylenetetrahydrofolate reductase (MTHFR) genes) were tested for their role in stroke. These first studies used just a couple of hundred samples or even less. The second and still ongoing period bridges the two other periods of research and has led to a rapid increase in the spectrum of functional variants of genes or genomic regions, discovered primarily in relation to other diseases, tested on larger stroke samples of clinically better stratified patients. Large numbers of these alleles were originally discovered by array-based genome-wide association studies. The third period of research involves the direct array screening of large samples; this approach represents significant progress for research in the field. Research into susceptibility genes for stroke has taught us that careful stratification of patients is critical, that susceptibility alleles are often shared between diseases, and that not all susceptibility factors that associate with clinical traits that are themselves risk factors for stroke (such as increase of triglycerides) necessarily represent susceptibility for stroke. Research so far has been mainly focused on large- and small-vessel associated stroke, and knowledge on other types of stroke, which represent much smaller population samples, is still very scarce. Although some susceptibility allele tests are on the palette of some direct-to-consumer companies, the clinical utility and clinical validity of these test results still do not support their use in clinical practice. PMID:20831840

Predictive value of callous-unemotional traits in a large community sample.

PubMed

Moran, Paul; Rowe, Richard; Flach, Clare; Briskman, Jacqueline; Ford, Tamsin; Maughan, Barbara; Scott, Stephen; Goodman, Robert

2009-11-01

Callous-unemotional (CU) traits in children and adolescents are increasingly recognized as a distinctive dimension of prognostic importance in clinical samples. Nevertheless, comparatively little is known about the longitudinal effects of these personality traits on the mental health of young people from the general population. Using a large representative sample of children and adolescents living in Great Britain, we set out to examine the effects of CU traits on a range of mental health outcomes measured 3 years after the initial assessment. Parents were interviewed to determine the presence of CU traits in a representative sample of 7,636 children and adolescents. The parents also completed the Strengths and Difficulties Questionnaire, a broad measure of childhood psychopathology. Three years later, parents repeated the Strengths and Difficulties Questionnaire. At 3-year follow-up, CU traits were associated with conduct, hyperactivity, emotional, and total symptom scores. After adjusting for the effects of all covariates, including baseline symptom score, CU traits remained robustly associated with the overall levels of conduct problems and emotional problems and with total psychiatric difficulties at 3-year follow-up. Callous-unemotional traits are independently associated with future psychiatric difficulties in children and adolescents. An assessment of CU traits adds small but significant improvements to the prediction of future psychopathology.

Professional Satisfaction and Dissatisfaction among Practicing Counselors: Implications for Counselor Education.

ERIC Educational Resources Information Center

Jaeger, Richard M.; Tesh, Anita S.

This study examined the degree and dimensions of professional satisfaction among a large, nationally-representative sample of practicing counselors. The objectives of the study included estimating the distribution of global professional satisfaction among practicing counselors; examining the relationships between counselors' global professional…

Evaluation of the NCPDP Structured and Codified Sig Format for e-prescriptions

PubMed Central

Burkhart, Q; Bell, Douglas S

2011-01-01

Objective To evaluate the ability of the structure and code sets specified in the National Council for Prescription Drug Programs Structured and Codified Sig Format to represent ambulatory electronic prescriptions. Design We parsed the Sig strings from a sample of 20 161 de-identified ambulatory e-prescriptions into variables representing the fields of the Structured and Codified Sig Format. A stratified random sample of these representations was then reviewed by a group of experts. For codified Sig fields, we attempted to map the actual words used by prescribers to the equivalent terms in the designated terminology. Measurements Proportion of prescriptions that the Format could fully represent; proportion of terms used that could be mapped to the designated terminology. Results The fields defined in the Format could fully represent 95% of Sigs (95% CI 93% to 97%), but ambiguities were identified, particularly in representing multiple-step instructions. The terms used by prescribers could be codified for only 60% of dose delivery methods, 84% of dose forms, 82% of vehicles, 95% of routes, 70% of sites, 33% of administration timings, and 93% of indications. Limitations The findings are based on a retrospective sample of ambulatory prescriptions derived mostly from primary care physicians. Conclusion The fields defined in the Format could represent most of the patient instructions in a large prescription sample, but prior to its mandatory adoption, further work is needed to ensure that potential ambiguities are addressed and that a complete set of terms is available for the codified fields. PMID:21613642

Coming of Age in Spain: The Self-identification, Beliefs and Self-Esteem of the Second Generation1

PubMed Central

Portes, Alejandro; Vickstrom, Erik; Aparicio, Rosa

2013-01-01

We review the literature on determinants of ethnic/national self-identities and self-esteem as a prelude to examining these outcomes among a large, statistically representative sample of second generation adolescents in Madrid and Barcelona. While these psycho-social outcomes are malleable, they still represent important dimensions of immigrant adaptation and can have significant consequences both for individual mobility and collective mobilizations. Current theories are largely based on data from the USA and other Anglophone countries. The availability of a new large Spanish survey allows us to test those theories in an entirely different socio-cultural context. The analysis concludes with a structural equations model that summarizes key determinants of national identities and self-esteem among children of immigrants in Spain. Theoretical and practical implications of these findings are discussed. PMID:21899520

Observational studies of patients in the emergency department: a comparison of 4 sampling methods.

PubMed

Valley, Morgan A; Heard, Kennon J; Ginde, Adit A; Lezotte, Dennis C; Lowenstein, Steven R

2012-08-01

We evaluate the ability of 4 sampling methods to generate representative samples of the emergency department (ED) population. We analyzed the electronic records of 21,662 consecutive patient visits at an urban, academic ED. From this population, we simulated different models of study recruitment in the ED by using 2 sample sizes (n=200 and n=400) and 4 sampling methods: true random, random 4-hour time blocks by exact sample size, random 4-hour time blocks by a predetermined number of blocks, and convenience or "business hours." For each method and sample size, we obtained 1,000 samples from the population. Using χ(2) tests, we measured the number of statistically significant differences between the sample and the population for 8 variables (age, sex, race/ethnicity, language, triage acuity, arrival mode, disposition, and payer source). Then, for each variable, method, and sample size, we compared the proportion of the 1,000 samples that differed from the overall ED population to the expected proportion (5%). Only the true random samples represented the population with respect to sex, race/ethnicity, triage acuity, mode of arrival, language, and payer source in at least 95% of the samples. Patient samples obtained using random 4-hour time blocks and business hours sampling systematically differed from the overall ED patient population for several important demographic and clinical variables. However, the magnitude of these differences was not large. Common sampling strategies selected for ED-based studies may affect parameter estimates for several representative population variables. However, the potential for bias for these variables appears small. Copyright © 2012. Published by Mosby, Inc.

Social Connectedness among International Students at an Australian University

ERIC Educational Resources Information Center

Rosenthal, Doreen Anne; Russell, Jean; Thomson, Garry

2007-01-01

A representative sample of undergraduate and postgraduate international students at a large Australian university (n = 979, 64% females) completed a mail-back survey examining their perceptions of social connectedness. Four aspects of social connectedness were investigated: (1) connectedness in Melbourne, (2) social mixing and interaction with…

Mental Health Correlates of the Victim-Perpetrator Relationship among Interpersonally Victimized Adolescents

ERIC Educational Resources Information Center

Lawyer, Steven R.; Ruggiero, Kenneth J.; Resnick, Heidi S.; Kilpatrick, Dean G.; Saunders, Benjamin E.

2006-01-01

This research examines mental health correlates of different victim-perpetrator relationships among adolescent victims of interpersonal violence. A large and nationally representative sample of adolescents (N = 4,023) responded to structured telephone interviews concerning mental health functioning (posttraumatic stress disorder--PTSD, major…

Intelligence and Physical Attractiveness

ERIC Educational Resources Information Center

Kanazawa, Satoshi

2011-01-01

This brief research note aims to estimate the magnitude of the association between general intelligence and physical attractiveness with large nationally representative samples from two nations. In the United Kingdom, attractive children are more intelligent by 12.4 IQ points (r=0.381), whereas in the United States, the correlation between…

In-stand scenic beauty of variable retention harvests and mature forests in the U.S. Pacific Northwest: the effects of basal area, density, retention pattern and down wood

Treesearch

R.G. Ribe

2009-01-01

Tensions between amenity- and timber-based economies in the U.S. and Canadian Pacific Northwest motivated a study of scenic beauty inside mature forests and timber harvests. A diverse sample of regional forests, measures of forest structure, and large, representative samples of photographs and public judges were employed to measure scenic beauty inside unharvested...

High-Resolution Near-Infrared Spectroscopy of an Equivalent Width-Selected Sample of Starbursting Dwarf Galaxies

NASA Technical Reports Server (NTRS)

Maseda, Michael V.; VanDerWeL, Arjen; DaChuna, Elisabete; Rix, Hans-Walter; Pacafichi, Camilla; Momcheva, Ivelina; Brammer, Gabriel B.; Franx, Marijn; VanDokkum, Pieter; Bell, Eric F.;

Safe Schools? Transgender Youth's School Experiences and Perceptions of School Climate.

PubMed

Day, Jack K; Perez-Brumer, Amaya; Russell, Stephen T

2018-06-01

The magnitude of gender identity-related disparities in school-based outcomes is unknown because of a lack of representative studies that include measures of gender identity. By utilizing a representative sample generalizable to a broader population, this study elucidates the size of gender identity-related disparities, independent of sexual orientation, in school experiences associated with school connectedness and perceptions of school climate. Additionally, the inclusion of and comparison to results of a large non-representative sample allows for more direct comparisons to previous studies of the school experiences of transgender youth. The analyses in this study primarily draw on a sample of 31,896 youth representative of the middle and high school population in California who participated in the 2013-2015 California Student Survey (a subsample of the California Healthy Kids Survey, which includes the largest known sample of transgender youth). Over half the sample identified their sex as female (51.3%), and 398 identified as transgender (1.0%). The sample was racially and ethnically diverse: 30.7% identified as multiracial, 33.0% as White, 11.1% as Asian, 7.4% as Black, and 52.9% as Hispanic. Findings from multilevel analyses show that relative to non-transgender youth, transgender youth were more likely to be truant from school, to experience victimization and bias-based bullying, and to report more negative perceptions of school climate, though did not differ in self-reported grades. The findings have implications for improving school policies and practices to create safer and more supportive school climates for all youth.

Can the composition and structure of the lower ocean crust and upper mantle be known without deep ocean drilling?

NASA Astrophysics Data System (ADS)

Dick, H.; Natland, J.

2003-04-01

No. With few exceptions, lower ocean crust sampled by dredge or submersible in tectonic windows such as Atlantis Bank in the Indian Ocean or the MARK area on the Mid-Atlantic Ridge are not representative of the ocean crust. They represent tectonic mixing of rocks from the mantle and crust on large faults that also localize late magmatic intrusion. Where this can be sorted out, the in-situ crustal sections may generally represent a sub-horizontal cross-section through the lower crust and mantle and not a vertical one. The gabbroic rocks exposed represent largely high-level intrusions, highly hybridized by late melt flow along deep faults, or highly evolved gabbro at the distal ends of larger intrusions emplaced into the mantle near transforms. Oceanic gabbros have average compositions that lie outside the range of primary MORB compositions, and rarely are equivalent to spatially associated MORB either as a parent to, or as a residue of their crystallization. Oceanic gabbros sampled from these complexes generally are very coarse-grained, and are unlike those seen in nearly all ophiolites and layered intrusions. In addition, there are few exposures of gabbro and lower ocean crust and mantle in Pacific tectonic windows, though there the possibility of more representative sections is greater due to their exposure in propagating rifts. Limited samples of the mantle from near the midpoints of ocean ridge segments at slow-spreading rifts are from anomalous crustal environments such as ultra-slow spreading ridges or failed rifts. These include abundant dunites, as opposed to samples from fracture zones, which contain only about 1% dunite. While this indicates focused mantle flow towards the midpoint of a ridge, it also shows that fracture zone peridotites are not fully representative of the oceanic upper mantle. Major classes of rocks common in ophiolites, such as fine to medium grained layered primitive olivine gabbros, troctolites, wherlites and dunites, sheeted dikes, and epidosites are rarely or even not exposed. Models of lower ocean crust stratigraphy drawn from deep sea sampling, certainly from slow spreading ridges, do not match those for major intact ophiolites. Thus the ophiolite hypothesis remains unconfirmed for the lower ocean crust and shallow mantle, and it is nearly impossible to accurately identify the ocean ridge environment of any one ophiolite. The one deep drill hole that exists in lower ocean crust, 1.5 km Hole 735B, has a bulk composition too fractionated to mass balance MORB back to a primary mantle melt composition. Thus, a large mass of primitive cumulates is missing and could be situated in the crust below the base of the hole or in the underlying mantle. This is an unresolved question that is critical to understanding the evolution of the most common magma on earth: MORB. Since lower ocean crust and mantle represent a major portion of the crust and the exchange of mass, heat and volatiles from the earth's interior to its exterior this leaves a major hole in our understanding of the global geochemical and tectonic cycle which can only be filled by deep drilling.

Stratification of American hearing aid users by age and audiometric characteristics: a method for representative sampling.

PubMed

Aronoff, Justin M; Yoon, Yang-soo; Soli, Sigfrid D

2010-06-01

Stratified sampling plans can increase the accuracy and facilitate the interpretation of a dataset characterizing a large population. However, such sampling plans have found minimal use in hearing aid (HA) research, in part because of a paucity of quantitative data on the characteristics of HA users. The goal of this study was to devise a quantitatively derived stratified sampling plan for HA research, so that such studies will be more representative and generalizable, and the results obtained using this method are more easily reinterpreted as the population changes. Pure-tone average (PTA) and age information were collected for 84,200 HAs acquired in 2006 and 2007. The distribution of PTA and age was quantified for each HA type and for a composite of all HA users. Based on their respective distributions, PTA and age were each divided into three groups, the combination of which defined the stratification plan. The most populous PTA and age group was also subdivided, allowing greater homogeneity within strata. Finally, the percentage of users in each stratum was calculated. This article provides a stratified sampling plan for HA research, based on a quantitative analysis of the distribution of PTA and age for HA users. Adopting such a sampling plan will make HA research results more representative and generalizable. In addition, data acquired using such plans can be reinterpreted as the HA population changes.

EPIFLUORESCENCE MICROSCOPY AND SOLID PHASE CYTOMETRY AS CONFIRMATORY METHODS FOR THE ENUMERATION OF PROTOZOA BY FLOW CYTOMETRY

EPA Science Inventory

The detection of infective protozoan parasites contained in large volume environmental samples represents a unique challenge in environmental parasitology. Compounding this problem is the fact that infective stages of many protozoan parasites do not readily replicate in media or ...

Characteristics of the Healthy Brain Project Sample: Representing Diversity among Study Participants

ERIC Educational Resources Information Center

Bryant, Lucinda L.; Laditka, James N.; Laditka, Sarah B.; Mathews, Anna E.

2009-01-01

Purpose: Description of study participants and documentation of the desired diversity in the Prevention Research Centers Healthy Aging Research Network's Workgroup on Promoting Cognitive Health large multisite study designed to examine attitudes about brain health, behaviors associated with its maintenance, and information-receiving preferences…

Old Wine, New Bottle? Comparing Interpersonal Bullying and Cyberbullying Victimization

ERIC Educational Resources Information Center

Payne, Allison Ann; Hutzell, Kirsten L.

2017-01-01

This study uses a large nationally representative sample to compare and contrast interpersonal bullying and cyberbullying by asking the following questions: (a) How does the prevalence of cyberbullying victimization compare with the prevalence of interpersonal bullying victimization? (b) How does the relationship between demographic predictors and…

Birth-Order Effects in the Academically Talented.

ERIC Educational Resources Information Center

Parker, Wayne D.

1998-01-01

Birth-order position was studied among 828 academically talented sixth-grade students. When compared to census data, the sample was disproportionately composed of first-born students. However, this effect was largely explained by the covariate of family size, with small families over represented among the gifted. Other findings indicated no…

ALIEN SPECIES IMPORTANTANCE IN NATIVE VEGETATION ALONG WADEABLE STREAMS, JOHN DAY RIVER BASIN, OREGON, USA

EPA Science Inventory

We evaluated the importance of alien species in existing vegetation along wadeable streams of a large, topographically diverse river basin in eastern Oregon, USA; sampling 165 plots (30 × 30 m) across 29 randomly selected 1-km stream reaches. Plots represented eight streamside co...

Too Many Friends: Social Integration, Network Cohesion and Adolescent Depressive Symptoms

ERIC Educational Resources Information Center

Falci, Christina; McNeely, Clea

2009-01-01

Using a nationally representative sample of adolescents, we examine associations among social integration (network size), network cohesion (alter-density), perceptions of social relationships (e.g., social support) and adolescent depressive symptoms. We find that adolescents with either too large or too small a network have higher levels of…

The Health and Wellbeing of International Students at an Australian University

ERIC Educational Resources Information Center

Rosenthal, Doreen Anne; Russell, Jean; Thomson, Garry

2008-01-01

A representative sample of undergraduate and postgraduate international students at a large Australian university (n=979, 64% females) completed a mail-back survey of their health and wellbeing. Most students evaluated their current and previous physical and mental health positively. Health-related risk practices such as unprotected sexual…

The Relationship between Father Residency and a Child's ADHD Symptoms

ERIC Educational Resources Information Center

Sulak, Tracey N.; Barnard-Brak, Lucy; Frederick, Karen

2012-01-01

Attention deficit hyperactivity disorder (ADHD) is a commonly diagnosed neuropsychological disorder among school-aged children. The purpose of the current study was to examine the relationship between father residency status and children's symptoms of ADHD using a large, nationally representative and community-based sample. To achieve this…

Does Participation in Music and Performing Arts Influence Child Development?

ERIC Educational Resources Information Center

Foster, E. Michael; Jenkins, Jade V. Marcus

2017-01-01

This article reconsiders the association between childhood arts participation and cognitive and developmental outcomes. Using data from a large, nationally representative sample with extensive covariates, we employ propensity score weighting to adjust comparisons of children who do and do not participate in arts education (music and performing…

Human and bovine viruses in urban and rural streams: Hydrologic and season patterns of wastewater influence

USDA-ARS?s Scientific Manuscript database

Viruses are the cause of many waterborne diseases contracted from fecal-contaminated waters. Collection of samples that properly represent virus concentrations throughout relevant hydrologic periods has historically been difficult due to the large water volume collection and filtration required for ...

Flip This Classroom: A Comparative Study

ERIC Educational Resources Information Center

Unruh, Tiffany; Peters, Michelle L.; Willis, Jana

2016-01-01

The purpose of this research was to compare the beliefs and attitudes of teachers using the flipped versus the traditional class model. Survey and interview data were collected from a matched sample of in-service teachers representing both models from a large suburban southeastern Texas school district. The Attitude Towards Technology Scale, the…

Confirmation of Small Dynamical and Stellar Masses for Extreme Emission Line Galaxies at z Approx. 2

NASA Technical Reports Server (NTRS)

Maseda, Michael V.; van Der Wel, Arjen; da Cunha, Elisabete; Rix, Hans-Walter; Pacifici, Camilla; Momcheva, Ivelina; Brammer, Gabriel B.; Franx, Marijn; van Dokkum, Pieter; Bell, Eric F.;

Development of new demi-span equations from a nationally representative sample of adults to estimate maximal adult height.

PubMed

Hirani, Vasant; Tabassum, Faiza; Aresu, Maria; Mindell, Jennifer

2010-08-01

Various measures have been used to estimate height when assessing nutritional status. Current equations to obtain demi-span equivalent height (DEH(Bassey)) are based on a small sample from a single study. The objectives of this study were to develop more robust DEH equations from a large number of men (n = 591) and women (n = 830) aged 25-45 y from a nationally representative cross-sectional sample (Health Survey for England 2007). Sex-specific regression equations were produced from young adults' (aged 25-45 y) measured height and demi-span to estimate new DEH equations (DEH(new)). DEH in people aged >or= 65 y was calculated using DEH(new). DEH(new) estimated current height in people aged 25-45 y with a mean difference of 0.04 in men (P = 0.80) and -0.29 in women (P = 0.05). Height, demi-span, DEH(new), and DEH(Bassey) declined by age group in both sexes aged >or=65 y (P < 0.05); DEH were larger than the measured height for all age groups (mean difference between DEH(new) and current height was -2.64 in men and -3.16 in women; both P < 0.001). Comparisons of DEH estimates showed good agreement, but DEH(new) was significantly higher than DEH(Bassey) in each age and sex group in older people. The new equations that are based on a large, randomly selected, nationally representative sample of young adults are more robust for predicting current height in young adults when height measurements are unavailable and can be used in the future to predict maximal adult height more accurately in currently young adults as they age.

Ribosomal RNA gene detection and targeted culture of novel nitrogen-responsive fungal taxa from temperate pine forest soil.

PubMed

Hesse, Cedar N; Torres-Cruz, Terry J; Tobias, Terri Billingsley; Al-Matruk, Maryam; Porras-Alfaro, Andrea; Kuske, Cheryl R

Soil fungal communities are responsible for carbon and nitrogen (N) cycling. The high complexity of the soil fungal community and the high proportion of taxonomically unidentifiable sequences confound ecological interpretations in field studies because physiological information is lacking for many organisms known only by their rRNA sequences. This situation forces experimental comparisons to be made at broader taxonomic racks where functions become difficult to infer. The objective of this study was to determine OTU (operational taxonomic units) level responses of the soil fungal community to N enrichment in a temperate pine forest experiment and to use the sequencing data to guide culture efforts of novel N-responsive fungal taxa. Replicate samples from four soil horizons (up to 10 cm depth) were obtained from ambient, enriched CO 2 and N-fertilization plots. Through a fungal large subunit rRNA gene (LSU) sequencing survey, we identified two novel fungal clades that were abundant in our soil sampling (representing up to 27% of the sequences in some samples) and responsive to changes in soil N. The two N-responsive taxa with no predicted taxonomic association were targeted for isolation and culturing from specific soil samples where their sequences were abundant. Representatives of both OTUs were successfully cultured using a filtration approach. One taxon (OTU6) was most closely related to Saccharomycotina; the second taxon (OTU69) was most closely related to Mucoromycotina. Both taxa likely represent novel species. This study shows how observation of specific OTUs level responses to altered N status in a large rRNA gene field survey provided the impetus to design targeted culture approaches for isolation of novel N-responsive fungal taxa.

Human iPSC-derived neurons and lymphoblastoid cells for personalized medicine research in neuropsychiatric disorders.

PubMed

Gurwitz, David

2016-09-01

The development and clinical implementation of personalized medicine crucially depends on the availability of high-quality human biosamples; animal models, although capable of modeling complex human diseases, cannot reflect the large variation in the human genome, epigenome, transcriptome, proteome, and metabolome. Although the biosamples available from public biobanks that store human tissues and cells may represent the large human diversity for most diseases, these samples are not always sufficient for developing biomarkers for patient-tailored therapies for neuropsychiatric disorders. Postmortem human tissues are available from many biobanks; nevertheless, collections of neuronal human cells from large patient cohorts representing the human diversity remain scarce. Two tools are gaining popularity for personalized medicine research on neuropsychiatric disorders: human induced pluripotent stem cell-derived neurons and human lymphoblastoid cell lines. This review examines and contrasts the advantages and limitations of each tool for personalized medicine research.

A sampling procedure to guide the collection of narrow-band, high-resolution spatially and spectrally representative reflectance data. [satellite imagery of earth resources

NASA Technical Reports Server (NTRS)

Brand, R. R.; Barker, J. L.

1983-01-01

A multistage sampling procedure using image processing, geographical information systems, and analytical photogrammetry is presented which can be used to guide the collection of representative, high-resolution spectra and discrete reflectance targets for future satellite sensors. The procedure is general and can be adapted to characterize areas as small as minor watersheds and as large as multistate regions. Beginning with a user-determined study area, successive reductions in size and spectral variation are performed using image analysis techniques on data from the Multispectral Scanner, orbital and simulated Thematic Mapper, low altitude photography synchronized with the simulator, and associated digital data. An integrated image-based geographical information system supports processing requirements.

The ESO Diffuse Interstellar Band Large Exploration Survey (EDIBLES)

NASA Astrophysics Data System (ADS)

Cami, J.; Cox, N. L.; Farhang, A.; Smoker, J.; Elyajouri, M.; Lallement, R.; Bacalla, X.; Bhatt, N. H.; Bron, E.; Cordiner, M. A.; de Koter, A..; Ehrenfreund, P.; Evans, C.; Foing, B. H.; Javadi, A.; Joblin, C.; Kaper, L.; Khosroshahi, H. G.; Laverick, M.; Le Petit, F..; Linnartz, H.; Marshall, C. C.; Monreal-Ibero, A.; Mulas, G.; Roueff, E.; Royer, P.; Salama, F.; Sarre, P. J.; Smith, K. T.; Spaans, M.; van Loon, J. T..; Wade, G.

2018-03-01

The ESO Diffuse Interstellar Band Large Exploration Survey (EDIBLES) is a Large Programme that is collecting high-signal-to-noise (S/N) spectra with UVES of a large sample of O and B-type stars covering a large spectral range. The goal of the programme is to extract a unique sample of high-quality interstellar spectra from these data, representing different physical and chemical environments, and to characterise these environments in great detail. An important component of interstellar spectra is the diffuse interstellar bands (DIBs), a set of hundreds of unidentified interstellar absorption lines. With the detailed line-of-sight information and the high-quality spectra, EDIBLES will derive strong constraints on the potential DIB carrier molecules. EDIBLES will thus guide the laboratory experiments necessary to identify these interstellar “mystery molecules”, and turn DIBs into powerful diagnostics of their environments in our Milky Way Galaxy and beyond. We present some preliminary results showing the unique capabilities of the EDIBLES programme.

Assessment of fish assemblages and minimum sampling effort required to determine botic integrity of large rivers in southern Idaho, 2002

USGS Publications Warehouse

Maret, Terry R.; Ott, D.S.

2004-01-01

width was determined to be sufficient for collecting an adequate number of fish to estimate species richness and evaluate biotic integrity. At most sites, about 250 fish were needed to effectively represent 95 percent of the species present. Fifty-three percent of the sites assessed, using an IBI developed specifically for large Idaho rivers, received scores of less than 50, indicating poor biotic integrity.

African Baobabs with False Inner Cavities: The Radiocarbon Investigation of the Lebombo Eco Trail Baobab

PubMed Central

Patrut, Adrian; Woodborne, Stephan; von Reden, Karl F.; Hall, Grant; Hofmeyr, Michele; Lowy, Daniel A.; Patrut, Roxana T.

2015-01-01

The article reports the radiocarbon investigation results of the Lebombo Eco Trail tree, a representative African baobab from Mozambique. Several wood samples collected from the large inner cavity and from the outer part of the tree were investigated by AMS radiocarbon dating. According to dating results, the age values of all samples increase from the sampling point with the distance into the wood. For samples collected from the cavity walls, the increase of age values with the distance into the wood (up to a point of maximum age) represents a major anomaly. The only realistic explanation for this anomaly is that such inner cavities are, in fact, natural empty spaces between several fused stems disposed in a ring-shaped structure. We named them false cavities. Several important differences between normal cavities and false cavities are presented. Eventually, we dated other African baobabs with false inner cavities. We found that this new architecture enables baobabs to reach large sizes and old ages. The radiocarbon date of the oldest sample was 1425 ± 24 BP, which corresponds to a calibrated age of 1355 ± 15 yr. The dating results also show that the Lebombo baobab consists of five fused stems, with ages between 900 and 1400 years; these five stems build the complete ring. The ring and the false cavity closed 800–900 years ago. The results also indicate that the stems stopped growing toward the false cavity over the past 500 years. PMID:25621989

Defining And Characterizing Sample Representativeness For DWPF Melter Feed Samples

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

2013-10-29

Representative sampling is important throughout the Defense Waste Processing Facility (DWPF) process, and the demonstrated success of the DWPF process to achieve glass product quality over the past two decades is a direct result of the quality of information obtained from the process. The objective of this report was to present sampling methods that the Savannah River Site (SRS) used to qualify waste being dispositioned at the DWPF. The goal was to emphasize the methodology, not a list of outcomes from those studies. This methodology includes proven methods for taking representative samples, the use of controlled analytical methods, and datamore » interpretation and reporting that considers the uncertainty of all error sources. Numerous sampling studies were conducted during the development of the DWPF process and still continue to be performed in order to evaluate options for process improvement. Study designs were based on use of statistical tools applicable to the determination of uncertainties associated with the data needs. Successful designs are apt to be repeated, so this report chose only to include prototypic case studies that typify the characteristics of frequently used designs. Case studies have been presented for studying in-tank homogeneity, evaluating the suitability of sampler systems, determining factors that affect mixing and sampling, comparing the final waste glass product chemical composition and durability to that of the glass pour stream sample and other samples from process vessels, and assessing the uniformity of the chemical composition in the waste glass product. Many of these studies efficiently addressed more than one of these areas of concern associated with demonstrating sample representativeness and provide examples of statistical tools in use for DWPF. The time when many of these designs were implemented was in an age when the sampling ideas of Pierre Gy were not as widespread as they are today. Nonetheless, the engineers and statisticians used carefully thought out designs that systematically and economically provided plans for data collection from the DWPF process. Key shared features of the sampling designs used at DWPF and the Gy sampling methodology were the specification of a standard for sample representativeness, an investigation that produced data from the process to study the sampling function, and a decision framework used to assess whether the specification was met based on the data. Without going into detail with regard to the seven errors identified by Pierre Gy, as excellent summaries are readily available such as Pitard [1989] and Smith [2001], SRS engineers understood, for example, that samplers can be biased (Gy's extraction error), and developed plans to mitigate those biases. Experiments that compared installed samplers with more representative samples obtained directly from the tank may not have resulted in systematically partitioning sampling errors into the now well-known error categories of Gy, but did provide overall information on the suitability of sampling systems. Most of the designs in this report are related to the DWPF vessels, not the large SRS Tank Farm tanks. Samples from the DWPF Slurry Mix Evaporator (SME), which contains the feed to the DWPF melter, are characterized using standardized analytical methods with known uncertainty. The analytical error is combined with the established error from sampling and processing in DWPF to determine the melter feed composition. This composition is used with the known uncertainty of the models in the Product Composition Control System (PCCS) to ensure that the wasteform that is produced is comfortably within the acceptable processing and product performance region. Having the advantage of many years of processing that meets the waste glass product acceptance criteria, the DWPF process has provided a considerable amount of data about itself in addition to the data from many special studies. Demonstrating representative sampling directly from the large Tank Farm tanks is a difficult, if not unsolvable enterprise due to limited accessibility. However, the consistency and the adequacy of sampling and mixing at SRS could at least be studied under the controlled process conditions based on samples discussed by Ray and others [2012a] in Waste Form Qualification Report (WQR) Volume 2 and the transfers from Tanks 40H and 51H to the Sludge Receipt and Adjustment Tank (SRAT) within DWPF. It is important to realize that the need for sample representativeness becomes more stringent as the material gets closer to the melter, and the tanks within DWPF have been studied extensively to meet those needs.« less

Reducing representativeness and sampling errors in radio occultation-radiosonde comparisons

NASA Astrophysics Data System (ADS)

Gilpin, Shay; Rieckh, Therese; Anthes, Richard

2018-05-01

Radio occultation (RO) and radiosonde (RS) comparisons provide a means of analyzing errors associated with both observational systems. Since RO and RS observations are not taken at the exact same time or location, temporal and spatial sampling errors resulting from atmospheric variability can be significant and inhibit error analysis of the observational systems. In addition, the vertical resolutions of RO and RS profiles vary and vertical representativeness errors may also affect the comparison. In RO-RS comparisons, RO observations are co-located with RS profiles within a fixed time window and distance, i.e. within 3-6 h and circles of radii ranging between 100 and 500 km. In this study, we first show that vertical filtering of RO and RS profiles to a common vertical resolution reduces representativeness errors. We then test two methods of reducing horizontal sampling errors during RO-RS comparisons: restricting co-location pairs to within ellipses oriented along the direction of wind flow rather than circles and applying a spatial-temporal sampling correction based on model data. Using data from 2011 to 2014, we compare RO and RS differences at four GCOS Reference Upper-Air Network (GRUAN) RS stations in different climatic locations, in which co-location pairs were constrained to a large circle ( ˜ 666 km radius), small circle ( ˜ 300 km radius), and ellipse parallel to the wind direction ( ˜ 666 km semi-major axis, ˜ 133 km semi-minor axis). We also apply a spatial-temporal sampling correction using European Centre for Medium-Range Weather Forecasts Interim Reanalysis (ERA-Interim) gridded data. Restricting co-locations to within the ellipse reduces root mean square (RMS) refractivity, temperature, and water vapor pressure differences relative to RMS differences within the large circle and produces differences that are comparable to or less than the RMS differences within circles of similar area. Applying the sampling correction shows the most significant reduction in RMS differences, such that RMS differences are nearly identical to the sampling correction regardless of the geometric constraints. We conclude that implementing the spatial-temporal sampling correction using a reliable model will most effectively reduce sampling errors during RO-RS comparisons; however, if a reliable model is not available, restricting spatial comparisons to within an ellipse parallel to the wind flow will reduce sampling errors caused by horizontal atmospheric variability.

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

PubMed

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

2017-02-10

The proteome analysis of bile fluid represents a promising strategy to identify biomarker candidates for various diseases of the hepatobiliary system. However, to obtain substantive results in biomarker discovery studies large patient cohorts necessarily need to be analyzed. Consequently, this would lead to an unmanageable number of samples to be analyzed if sample preparation protocols with extensive fractionation methods are applied. Hence, the performance of simple workflows allowing for "one sample, one shot" experiments have been evaluated in this study. In detail, sixteen different protocols implying modifications at the stages of desalting, delipidation, deglycosylation and tryptic digestion have been examined. Each method has been individually evaluated regarding various performance criteria and comparative analyses have been conducted to uncover possible complementarities. Here, the best performance in terms of proteome coverage has been assessed for a combination of acetone precipitation with in-gel digestion. Finally, a mapping of all obtained protein identifications with putative biomarkers for hepatocellular carcinoma (HCC) and cholangiocellular carcinoma (CCC) revealed several proteins easily detectable in bile fluid. These results can build the basis for future studies with large and well-defined patient cohorts in a more disease-related context. Human bile fluid is a proximal body fluid and supposed to be a potential source of disease markers. However, due to its biochemical composition, the proteome analysis of bile fluid still represents a challenging task and is therefore mostly conducted using extensive fractionation procedures. This in turn leads to a high number of mass spectrometric measurements for one biological sample. Considering the fact that in order to overcome the biological variability a high number of biological samples needs to be analyzed in biomarker discovery studies, this leads to the dilemma of an unmanageable number of necessary MS-based analyses. Hence, easy sample preparation protocols are demanded representing a compromise between proteome coverage and simplicity. In the presented study, such protocols have been evaluated regarding various technical criteria (e.g. identification rates, missed cleavages, chromatographic separation) uncovering the strengths and weaknesses of various methods. Furthermore, a cumulative bile proteome list has been generated that extends the current bile proteome catalog by 248 proteins. Finally, a mapping with putative biomarkers for hepatocellular carcinoma (HCC) and cholangiocellular carcinoma (CCC) derived from tissue-based studies, revealed several of these proteins being easily and reproducibly detectable in human bile. Therefore, the presented technical work represents a solid base for future disease-related studies. Copyright © 2016 Elsevier B.V. All rights reserved.

Large-Scale Spatial Distribution Patterns of Gastropod Assemblages in Rocky Shores

PubMed Central

Miloslavich, Patricia; Cruz-Motta, Juan José; Klein, Eduardo; Iken, Katrin; Weinberger, Vanessa; Konar, Brenda; Trott, Tom; Pohle, Gerhard; Bigatti, Gregorio; Benedetti-Cecchi, Lisandro; Shirayama, Yoshihisa; Mead, Angela; Palomo, Gabriela; Ortiz, Manuel; Gobin, Judith; Sardi, Adriana; Díaz, Juan Manuel; Knowlton, Ann; Wong, Melisa; Peralta, Ana C.

2013-01-01

Gastropod assemblages from nearshore rocky habitats were studied over large spatial scales to (1) describe broad-scale patterns in assemblage composition, including patterns by feeding modes, (2) identify latitudinal pattern of biodiversity, i.e., richness and abundance of gastropods and/or regional hotspots, and (3) identify potential environmental and anthropogenic drivers of these assemblages. Gastropods were sampled from 45 sites distributed within 12 Large Marine Ecosystem regions (LME) following the NaGISA (Natural Geography in Shore Areas) standard protocol (www.nagisa.coml.org). A total of 393 gastropod taxa from 87 families were collected. Eight of these families (9.2%) appeared in four or more different LMEs. Among these, the Littorinidae was the most widely distributed (8 LMEs) followed by the Trochidae and the Columbellidae (6 LMEs). In all regions, assemblages were dominated by few species, the most diverse and abundant of which were herbivores. No latitudinal gradients were evident in relation to species richness or densities among sampling sites. Highest diversity was found in the Mediterranean and in the Gulf of Alaska, while highest densities were found at different latitudes and represented by few species within one genus (e.g. Afrolittorina in the Agulhas Current, Littorina in the Scotian Shelf, and Lacuna in the Gulf of Alaska). No significant correlation was found between species composition and environmental variables (r≤0.355, p>0.05). Contributing variables to this low correlation included invasive species, inorganic pollution, SST anomalies, and chlorophyll-a anomalies. Despite data limitations in this study which restrict conclusions in a global context, this work represents the first effort to sample gastropod biodiversity on rocky shores using a standardized protocol across a wide scale. Our results will generate more work to build global databases allowing for large-scale diversity comparisons of rocky intertidal assemblages. PMID:23967204

Determining timing of Alaska Range exhumation and glaciation through cosmogenic nuclide burial dating.

NASA Astrophysics Data System (ADS)

Sortor, R. N.; Goehring, B. M.; Bemis, S. P.; Ruleman, C.; Nichols, K. A.; Ward, D. J.; Frothingham, M.

2017-12-01

The Alaska Range is a transpressional orogen with modern exhumation initiating 6 Ma. The stratigraphic record of unroofing and uplift of the foreland basin is largely preserved along the northern flank of the Alaska Range in the Pliocene-Pleistocene aged Nenana Gravel, an extensive alluvial fan and braidplain deposit. Chronometric control on the Nenana Gravel is largely lacking, with the limited available age control based on a single Ar-Ar tephra date in an underlying unit and via stratigraphic inferences for the upper portions. Higher-resolution dating of the Nenana Gravel unit is imperative in order to quantify deposition rates and the timing of uplift and deformation of the foreland basin. Furthermore, a glacial unit has been found to lie unconformably on top of the unit at Suntrana Creek and may represent the initiation of glacial advances in the Alaska Range. We present a suite of 26Al/10Be cosmogenic nuclide burial ages collected from the lower, middle, and upper sections of the Nenana Gravel at Suntrana Creek, as well as the overlying glacial unit. Three samples from the lower Nenana Gravel yield an isochron burial age of 4.42+0.67/-0.13 Ma, which represents initiation of Nenana Gravel deposition and may equate to early unroofing of the Alaska Range. Two samples collected from the middle of the Nenana Gravel unit produced an average simple burial age of 2.25+/-0.45 Ma, with a single sample stratigraphically above dating to 0.99 +/-1.60. Two samples from the upper-most portion of the Nenana Gravel yielded an average simple burial age of 1.27+/-0.22 Ma, and one sample from the glacial unit overlying the Nenana Gravel was dated to 0.97+/-0.06 Ma, representing one of the earliest glacial advances in the region. In addition, the age of the glacial unit provides a minimum age for inception of foreland basin uplift and abandonment of the Nenana Gravel in this region.

The Preschool Learning Behaviors Scale: Dimensionality and External Validity in Head Start

ERIC Educational Resources Information Center

McDermott, Paul A.; Rikoon, Samuel H.; Waterman, Clare; Fantuzzo, John W.

2012-01-01

Given the importance of accurately gauging early childhood approaches to learning, this study reports evidence for the dimensionality and utility of the Preschool Learning Behaviors Scale for use with disadvantaged preschool children. Data from a large (N = 1,666) sample representative of urban Head Start classrooms revealed three reliable…

Stability and Volatility of STEM Career Interest in High School: A Gender Study

ERIC Educational Resources Information Center

Sadler, Philip M.; Sonnert, Gerhard; Hazari, Zahra; Tai, Robert

2012-01-01

This retrospective cohort study characterizes how interest in science, technology, engineering, mathematics (STEM) careers changes during high school for more than 6,000 students in a representative national sample of 34 two- and four-year colleges taking mandatory college English courses. Overall, large gender differences in career plans were…

Dietary Intake among U.S. Adults with Disability

ERIC Educational Resources Information Center

An, Ruopeng; Chiu, Chung-Yi

2015-01-01

Purpose: Physical, mental, and financial barriers among individuals with disability may limit their access to fruit and vegetable. In this study, we examined the relationship between disability status and vegetable, fruit, and fruit juice intake among U.S. adults aged 18 years and older using a large nationally representative sample. Methods:…

Correlates of Sexual Abuse and Smoking among French Adults

ERIC Educational Resources Information Center

King, Gary; Guilbert, Philippe; Ward, D. Gant; Arwidson, Pierre; Noubary, Farzad

2006-01-01

Objective: The goal of this study was to examine the association between sexual abuse (SA) and initiation, cessation, and current cigarette smoking among a large representative adult population in France. Method: A random sample size of 12,256 adults (18-75 years of age) was interviewed by telephone concerning demographic variables, health…

The Measurement and Evaluation of Social Attitudes in Two British Cohort Studies

ERIC Educational Resources Information Center

Cheng, Helen; Bynner, John; Wiggins, Richard; Schoon, Ingrid

2012-01-01

This paper presents an empirical evaluation of the internal consistency and validity of six attitudes scales assessing left-right beliefs, political cynicism, antiracism, libertarian-authoritarian views, and gender equality (two versions) in two large nationally representative samples of the British population born in 1958 and 1970. In the 1958…

Longitudinal Surveys of Australian Youth (LSAY): 1995 Cohort: User Guide. Technical Report 49

ERIC Educational Resources Information Center

National Centre for Vocational Education Research (NCVER), 2009

2009-01-01

The Longitudinal Surveys of Australian Youth (LSAY) is a research program that tracks young people as they move from school into further study, work and other destinations. It uses large, nationally representative samples of young people to collect information about education and training, work, and social development. It includes surveys…

Are There Stable Factors in Preadolescent Girls' Externalizing Behaviors?

ERIC Educational Resources Information Center

Loeber, Rolf; Pardini, Dustin A.; Hipwell, Alison; Stouthamer-Loeber, Magda; Keenan, Kate; Sembower, Mark A.

2009-01-01

Relatively little is known about the factor structure of disruptive behavior among preadolescent girls. The present study reports on exploratory and confirmatory factor analyses of disruptive girl behavior over four successive data waves as rated by parents and teachers in a large, representative community sample of girls (N = 2,451). Five factors…

Women and Minorities. Leaders in Transition: A National Study of Higher Education Administrators.

ERIC Educational Resources Information Center

Moore, Kathryn M.

Career issues, educational concerns, and the professional, educational, and personal backgrounds of 2,896 senior college administrators were studied, with focus on the status of women and minorities. Women represented 20 percent of the sample; minorities, 8 percent. Women and minorities were largely registrars, librarians, and financial aid…

Prevalence and Correlates of Screen-Based Media Use among Youths with Autism Spectrum Disorders

ERIC Educational Resources Information Center

Mazurek, Micah O.; Shattuck, Paul T.; Wagner, Mary; Cooper, Benjamin P.

2012-01-01

Anecdotal reports indicate that individuals with autism spectrum disorders (ASD) are often preoccupied with television, computers, and video games (screen-based media). However, few studies have examined this issue. The current study examined screen-based media use among a large, nationally representative sample of youths participating in the…

Ethnic Variations in the Connection between Work-Induced Family Separation and Turnover Intent

ERIC Educational Resources Information Center

Behnke, Andrew O.; MacDermid, Shelley M.; Anderson, James C.; Weiss, Howard M.

2010-01-01

Using conservation of resources theory, this study examines the role of resources in the relationship between work-induced family separation and workers' intentions to leave their employment and how these relationships vary across ethnic groups. Analyses of a large representative sample of military members reveal that family separation is…

Children's Task Oriented Patterns in Early Childhood: A Latent Transition Analysis

ERIC Educational Resources Information Center

Wang, Feihong; Algina, James; Snyder, Patricia; Cox, Martha; Vernon-Feagans, Lynne; Cox, Martha; Blair, Clancy; Burchinal, Margaret; Burton, Linda; Crnic, Keith; Crouter, Ann; Garrett-Peters, Patricia; Greenberg, Mark; Lanza, Stephanie; Mills-Koonce, Roger; Werner, Emily; Willoughby, Michael

2017-01-01

We examined individual differences and predictions of children's patterns in behavioral, emotional and attentional efforts toward challenging puzzle tasks at 24 and 35 months using data from a large longitudinal rural representative sample. Using latent transition analysis, we found four distinct task-oriented patterns in problem-solving tasks…

Development and Validation of a Measure of Interpersonal Strengths: The Inventory of Interpersonal Strengths

ERIC Educational Resources Information Center

Hatcher, Robert L.; Rogers, Daniel T.

2009-01-01

An Inventory of Interpersonal Strengths (IIS) was developed and validated in a series of large college student samples. Based on interpersonal theory and associated methods, the IIS was designed to assess positive characteristics representing the full range of interpersonal domains, including those generally thought to have negative qualities…

Reciprocal Effects between Fluid and Crystallized Intelligence and Their Dependence on Parents' Socioeconomic Status and Education

ERIC Educational Resources Information Center

Rindermann, Heiner; Flores-Mendoza, Carmen; Mansur-Alves, Marcela

2010-01-01

The investment theory of Cattell supposes an influence of fluid on crystallized intelligence. The development of fluid intelligence largely depends on biological factors, of crystallized intelligence on fluid intelligence and environmental stimulation. To test this theory two contrasting samples representing a broad ability range were chosen, a…

On the Determinants of Employment-Related Organised Education and Informal Learning

ERIC Educational Resources Information Center

Nilsson, Staffan; Rubenson, Kjell

2014-01-01

This paper analyses the distribution of employment-related organised education and informal learning in the Canadian workforce. The paper draws on a large-scale survey, the Changing Nature of Work and Lifelong Learning (WALL), which was based on structured and standardised telephone interviews with a representative sample of 5783 Canadian members…

Complementary Roles of Care and Behavioral Control in Classroom Management: The Self-Determination Theory Perspective

ERIC Educational Resources Information Center

Nie, Youyan; Lau, Shun

2009-01-01

This study examined how classroom management practices--care and behavioral control--were differentially associated with students' engagement, misbehavior, and satisfaction with school, using a large representative sample of 3196 Grade 9 students from 117 classes in Singapore. Results of hierarchical linear modeling showed differential relations.…

Conduct, Biological Factors and Adult Delinquency in a Longitudinal Perspective.

ERIC Educational Resources Information Center

Magnusson, David

In the course of a longitudinal research program conducted in Sweden, data were being collected on biological and psychological aspects of individual functioning and on environmental factors for a fairly large representative sample (approximately 1,000) of Swedish males and females between 10 and 27 years of age. Based on data from the…

Assessing Agreement between Multiple Raters with Missing Rating Information, Applied to Breast Cancer Tumour Grading

PubMed Central

Ellis, Ian O.; Green, Andrew R.; Hanka, Rudolf

2008-01-01

Background We consider the problem of assessing inter-rater agreement when there are missing data and a large number of raters. Previous studies have shown only ‘moderate’ agreement between pathologists in grading breast cancer tumour specimens. We analyse a large but incomplete data-set consisting of 24177 grades, on a discrete 1–3 scale, provided by 732 pathologists for 52 samples. Methodology/Principal Findings We review existing methods for analysing inter-rater agreement for multiple raters and demonstrate two further methods. Firstly, we examine a simple non-chance-corrected agreement score based on the observed proportion of agreements with the consensus for each sample, which makes no allowance for missing data. Secondly, treating grades as lying on a continuous scale representing tumour severity, we use a Bayesian latent trait method to model cumulative probabilities of assigning grade values as functions of the severity and clarity of the tumour and of rater-specific parameters representing boundaries between grades 1–2 and 2–3. We simulate from the fitted model to estimate, for each rater, the probability of agreement with the majority. Both methods suggest that there are differences between raters in terms of rating behaviour, most often caused by consistent over- or under-estimation of the grade boundaries, and also considerable variability in the distribution of grades assigned to many individual samples. The Bayesian model addresses the tendency of the agreement score to be biased upwards for raters who, by chance, see a relatively ‘easy’ set of samples. Conclusions/Significance Latent trait models can be adapted to provide novel information about the nature of inter-rater agreement when the number of raters is large and there are missing data. In this large study there is substantial variability between pathologists and uncertainty in the identity of the ‘true’ grade of many of the breast cancer tumours, a fact often ignored in clinical studies. PMID:18698346

The short-form version of the Depression Anxiety Stress Scales (DASS-21): construct validity and normative data in a large non-clinical sample.

PubMed

Henry, Julie D; Crawford, John R

2005-06-01

To test the construct validity of the short-form version of the Depression anxiety and stress scale (DASS-21), and in particular, to assess whether stress as indexed by this measure is synonymous with negative affectivity (NA) or whether it represents a related, but distinct, construct. To provide normative data for the general adult population. Cross-sectional, correlational and confirmatory factor analysis (CFA). The DASS-21 was administered to a non-clinical sample, broadly representative of the general adult UK population (N = 1,794). Competing models of the latent structure of the DASS-21 were evaluated using CFA. The model with optimal fit (RCFI = 0.94) had a quadripartite structure, and consisted of a general factor of psychological distress plus orthogonal specific factors of depression, anxiety, and stress. This model was a significantly better fit than a competing model that tested the possibility that the Stress scale simply measures NA. The DASS-21 subscales can validly be used to measure the dimensions of depression, anxiety, and stress. However, each of these subscales also taps a more general dimension of psychological distress or NA. The utility of the measure is enhanced by the provision of normative data based on a large sample.

DALMATIAN: An Algorithm for Automatic Cell Detection and Counting in 3D.

PubMed

Shuvaev, Sergey A; Lazutkin, Alexander A; Kedrov, Alexander V; Anokhin, Konstantin V; Enikolopov, Grigori N; Koulakov, Alexei A

2017-01-01

Current 3D imaging methods, including optical projection tomography, light-sheet microscopy, block-face imaging, and serial two photon tomography enable visualization of large samples of biological tissue. Large volumes of data obtained at high resolution require development of automatic image processing techniques, such as algorithms for automatic cell detection or, more generally, point-like object detection. Current approaches to automated cell detection suffer from difficulties originating from detection of particular cell types, cell populations of different brightness, non-uniformly stained, and overlapping cells. In this study, we present a set of algorithms for robust automatic cell detection in 3D. Our algorithms are suitable for, but not limited to, whole brain regions and individual brain sections. We used watershed procedure to split regional maxima representing overlapping cells. We developed a bootstrap Gaussian fit procedure to evaluate the statistical significance of detected cells. We compared cell detection quality of our algorithm and other software using 42 samples, representing 6 staining and imaging techniques. The results provided by our algorithm matched manual expert quantification with signal-to-noise dependent confidence, including samples with cells of different brightness, non-uniformly stained, and overlapping cells for whole brain regions and individual tissue sections. Our algorithm provided the best cell detection quality among tested free and commercial software.

K-Nearest Neighbor Algorithm Optimization in Text Categorization

NASA Astrophysics Data System (ADS)

Chen, Shufeng

2018-01-01

K-Nearest Neighbor (KNN) classification algorithm is one of the simplest methods of data mining. It has been widely used in classification, regression and pattern recognition. The traditional KNN method has some shortcomings such as large amount of sample computation and strong dependence on the sample library capacity. In this paper, a method of representative sample optimization based on CURE algorithm is proposed. On the basis of this, presenting a quick algorithm QKNN (Quick k-nearest neighbor) to find the nearest k neighbor samples, which greatly reduces the similarity calculation. The experimental results show that this algorithm can effectively reduce the number of samples and speed up the search for the k nearest neighbor samples to improve the performance of the algorithm.

Sampling maternal care behaviour in domestic dogs: What's the best approach?

PubMed

Czerwinski, Veronika H; Smith, Bradley P; Hynd, Philip I; Hazel, Susan J

2017-07-01

Our understanding of the frequency and duration of maternal care behaviours in the domestic dog during the first two postnatal weeks is limited, largely due to the inconsistencies in the sampling methodologies that have been employed. In order to develop a more concise picture of maternal care behaviour during this period, and to help establish the sampling method that represents these behaviours best, we compared a variety of time sampling methods Six litters were continuously observed for a total of 96h over postnatal days 3, 6, 9 and 12 (24h per day). Frequent (dam presence, nursing duration, contact duration) and infrequent maternal behaviours (anogenital licking duration and frequency) were coded using five different time sampling methods that included: 12-h night (1800-0600h), 12-h day (0600-1800h), one hour period during the night (1800-0600h), one hour period during the day (0600-1800h) and a one hour period anytime. Each of the one hour time sampling method consisted of four randomly chosen 15-min periods. Two random sets of four 15-min period were also analysed to ensure reliability. We then determined which of the time sampling methods averaged over the three 24-h periods best represented the frequency and duration of behaviours. As might be expected, frequently occurring behaviours were adequately represented by short (oneh) sampling periods, however this was not the case with the infrequent behaviour. Thus, we argue that the time sampling methodology employed must match the behaviour of interest. This caution applies to maternal behaviour in altricial species, such as canids, as well as all systematic behavioural observations utilising time sampling methodology. Copyright © 2017. Published by Elsevier B.V.

Large-volume constant-concentration sampling technique coupling with surface-enhanced Raman spectroscopy for rapid on-site gas analysis

NASA Astrophysics Data System (ADS)

Zhang, Zhuomin; Zhan, Yisen; Huang, Yichun; Li, Gongke

2017-08-01

In this work, a portable large-volume constant-concentration (LVCC) sampling technique coupling with surface-enhanced Raman spectroscopy (SERS) was developed for the rapid on-site gas analysis based on suitable derivatization methods. LVCC sampling technique mainly consisted of a specially designed sampling cell including the rigid sample container and flexible sampling bag, and an absorption-derivatization module with a portable pump and a gas flowmeter. LVCC sampling technique allowed large, alterable and well-controlled sampling volume, which kept the concentration of gas target in headspace phase constant during the entire sampling process and made the sampling result more representative. Moreover, absorption and derivatization of gas target during LVCC sampling process were efficiently merged in one step using bromine-thiourea and OPA-NH4+ strategy for ethylene and SO2 respectively, which made LVCC sampling technique conveniently adapted to consequent SERS analysis. Finally, a new LVCC sampling-SERS method was developed and successfully applied for rapid analysis of trace ethylene and SO2 from fruits. It was satisfied that trace ethylene and SO2 from real fruit samples could be actually and accurately quantified by this method. The minor concentration fluctuations of ethylene and SO2 during the entire LVCC sampling process were proved to be < 4.3% and 2.1% respectively. Good recoveries for ethylene and sulfur dioxide from fruit samples were achieved in range of 95.0-101% and 97.0-104% respectively. It is expected that portable LVCC sampling technique would pave the way for rapid on-site analysis of accurate concentrations of trace gas targets from real samples by SERS.

Large-volume constant-concentration sampling technique coupling with surface-enhanced Raman spectroscopy for rapid on-site gas analysis.

PubMed

Zhang, Zhuomin; Zhan, Yisen; Huang, Yichun; Li, Gongke

2017-08-05

In this work, a portable large-volume constant-concentration (LVCC) sampling technique coupling with surface-enhanced Raman spectroscopy (SERS) was developed for the rapid on-site gas analysis based on suitable derivatization methods. LVCC sampling technique mainly consisted of a specially designed sampling cell including the rigid sample container and flexible sampling bag, and an absorption-derivatization module with a portable pump and a gas flowmeter. LVCC sampling technique allowed large, alterable and well-controlled sampling volume, which kept the concentration of gas target in headspace phase constant during the entire sampling process and made the sampling result more representative. Moreover, absorption and derivatization of gas target during LVCC sampling process were efficiently merged in one step using bromine-thiourea and OPA-NH 4 + strategy for ethylene and SO 2 respectively, which made LVCC sampling technique conveniently adapted to consequent SERS analysis. Finally, a new LVCC sampling-SERS method was developed and successfully applied for rapid analysis of trace ethylene and SO 2 from fruits. It was satisfied that trace ethylene and SO 2 from real fruit samples could be actually and accurately quantified by this method. The minor concentration fluctuations of ethylene and SO 2 during the entire LVCC sampling process were proved to be <4.3% and 2.1% respectively. Good recoveries for ethylene and sulfur dioxide from fruit samples were achieved in range of 95.0-101% and 97.0-104% respectively. It is expected that portable LVCC sampling technique would pave the way for rapid on-site analysis of accurate concentrations of trace gas targets from real samples by SERS. Copyright © 2017 Elsevier B.V. All rights reserved.

Solid-Phase Extraction (SPE): Principles and Applications in Food Samples.

PubMed

Ötles, Semih; Kartal, Canan

2016-01-01

Solid-Phase Extraction (SPE) is a sample preparation method that is practised on numerous application fields due to its many advantages compared to other traditional methods. SPE was invented as an alternative to liquid/liquid extraction and eliminated multiple disadvantages, such as usage of large amount of solvent, extended operation time/procedure steps, potential sources of error, and high cost. Moreover, SPE can be plied to the samples combined with other analytical methods and sample preparation techniques optionally. SPE technique is a useful tool for many purposes through its versatility. Isolation, concentration, purification and clean-up are the main approaches in the practices of this method. Food structures represent a complicated matrix and can be formed into different physical stages, such as solid, viscous or liquid. Therefore, sample preparation step particularly has an important role for the determination of specific compounds in foods. SPE offers many opportunities not only for analysis of a large diversity of food samples but also for optimization and advances. This review aims to provide a comprehensive overview on basic principles of SPE and its applications for many analytes in food matrix.

Regional surnames and genetic structure in Great Britain.

PubMed

Kandt, Jens; Cheshire, James A; Longley, Paul A

2016-10-01

Following the increasing availability of DNA-sequenced data, the genetic structure of populations can now be inferred and studied in unprecedented detail. Across social science, this innovation is shaping new bio-social research agendas, attracting substantial investment in the collection of genetic, biological and social data for large population samples. Yet genetic samples are special because the precise populations that they represent are uncertain and ill-defined. Unlike most social surveys, a genetic sample's representativeness of the population cannot be established by conventional procedures of statistical inference, and the implications for population-wide generalisations about bio-social phenomena are little understood. In this paper, we seek to address these problems by linking surname data to a censored and geographically uneven sample of DNA scans, collected for the People of the British Isles study. Based on a combination of global and local spatial correspondence measures, we identify eight regions in Great Britain that are most likely to represent the geography of genetic structure of Great Britain's long-settled population. We discuss the implications of this regionalisation for bio-social investigations. We conclude that, as the often highly selective collection of DNA and biomarkers becomes a more common practice, geography is crucial to understanding variation in genetic information within diverse populations.

Dental size and shape in the Roman imperial age: two examples from the area of Rome.

PubMed

Manzi, G; Santandrea, E; Passarello, P

1997-04-01

Different socioeconomic strata of Roman imperial age are represented by two large dental samples recovered from archaeological excavations near Rome, Italy. Teeth are investigated for crown dimensions and morphological variants. One sample, comprising 1,465 permanent teeth, represents the rural town of Lucus Feroniae (LFR) and is mainly composed of slaves and war veterans. The other, comprising 734 teeth from the Isola Sacra necropolis at Portus Romae (NIS), represents the "middle class" segment of an urban population. Both series show small dental dimensions and fit at the lower end of the trend toward dental reduction in Europe from the Upper Paleolithic to the historical times. The urban sample is less variable metrically and less sexually dimorphic than the rural one. The analysis of discrete crown traits shows absence of rare phenotypic variants in both series. The urban sample is also less variable in this last respect, suggesting that the gene pool of this particular "stratum" of the NIS population was more homogeneous than that of LFR. The occurrence of enamel hypoplasia indicates that metabolic stress during growth and development was similar in LFR and NIS. The overall set of available data is evaluated in the light of the history of the two Roman sites and the composition of each population.

A 2D Fourier tool for the analysis of photo-elastic effect in large granular assemblies

NASA Astrophysics Data System (ADS)

Leśniewska, Danuta

2017-06-01

Fourier transforms are the basic tool in constructing different types of image filters, mainly those reducing optical noise. Some DIC or PIV software also uses frequency space to obtain displacement fields from a series of digital images of a deforming body. The paper presents series of 2D Fourier transforms of photo-elastic transmission images, representing large pseudo 2D granular assembly, deforming under varying boundary conditions. The images related to different scales were acquired using the same image resolution, but taken at different distance from the sample. Fourier transforms of images, representing different stages of deformation, reveal characteristic features at the three (`macro-`, `meso-` and `micro-`) scales, which can serve as a data to study internal order-disorder transition within granular materials.

Likelihood inference of non-constant diversification rates with incomplete taxon sampling.

PubMed

Höhna, Sebastian

2014-01-01

Large-scale phylogenies provide a valuable source to study background diversification rates and investigate if the rates have changed over time. Unfortunately most large-scale, dated phylogenies are sparsely sampled (fewer than 5% of the described species) and taxon sampling is not uniform. Instead, taxa are frequently sampled to obtain at least one representative per subgroup (e.g. family) and thus to maximize diversity (diversified sampling). So far, such complications have been ignored, potentially biasing the conclusions that have been reached. In this study I derive the likelihood of a birth-death process with non-constant (time-dependent) diversification rates and diversified taxon sampling. Using simulations I test if the true parameters and the sampling method can be recovered when the trees are small or medium sized (fewer than 200 taxa). The results show that the diversification rates can be inferred and the estimates are unbiased for large trees but are biased for small trees (fewer than 50 taxa). Furthermore, model selection by means of Akaike's Information Criterion favors the true model if the true rates differ sufficiently from alternative models (e.g. the birth-death model is recovered if the extinction rate is large and compared to a pure-birth model). Finally, I applied six different diversification rate models--ranging from a constant-rate pure birth process to a decreasing speciation rate birth-death process but excluding any rate shift models--on three large-scale empirical phylogenies (ants, mammals and snakes with respectively 149, 164 and 41 sampled species). All three phylogenies were constructed by diversified taxon sampling, as stated by the authors. However only the snake phylogeny supported diversified taxon sampling. Moreover, a parametric bootstrap test revealed that none of the tested models provided a good fit to the observed data. The model assumptions, such as homogeneous rates across species or no rate shifts, appear to be violated.

Signal Sampling for Efficient Sparse Representation of Resting State FMRI Data

PubMed Central

Ge, Bao; Makkie, Milad; Wang, Jin; Zhao, Shijie; Jiang, Xi; Li, Xiang; Lv, Jinglei; Zhang, Shu; Zhang, Wei; Han, Junwei; Guo, Lei; Liu, Tianming

2015-01-01

As the size of brain imaging data such as fMRI grows explosively, it provides us with unprecedented and abundant information about the brain. How to reduce the size of fMRI data but not lose much information becomes a more and more pressing issue. Recent literature studies tried to deal with it by dictionary learning and sparse representation methods, however, their computation complexities are still high, which hampers the wider application of sparse representation method to large scale fMRI datasets. To effectively address this problem, this work proposes to represent resting state fMRI (rs-fMRI) signals of a whole brain via a statistical sampling based sparse representation. First we sampled the whole brain’s signals via different sampling methods, then the sampled signals were aggregate into an input data matrix to learn a dictionary, finally this dictionary was used to sparsely represent the whole brain’s signals and identify the resting state networks. Comparative experiments demonstrate that the proposed signal sampling framework can speed-up by ten times in reconstructing concurrent brain networks without losing much information. The experiments on the 1000 Functional Connectomes Project further demonstrate its effectiveness and superiority. PMID:26646924

Carbon-13 Isotopic Abundance and Concentration of Atmospheric Methane for Background Air in the Southern and Northern Hemispheres from 1978 to 1989 (NDP-049)

DOE Data Explorer

Stevens, C. M. [Chemical Technology Division, Argonne National Laboratory, Argonne, Illinois (USA)

2012-01-01

This data package presents atmospheric CH4 concentration and 13C isotopic abundance data derived from air samples collected over the period 1978-1989 at globally distributed clean-air sites. The data set comprises 201 records, 166 from the Northern Hemisphere and 35 from the Southern Hemisphere. The air samples were collected mostly in rural or marine locations remote from large sources of CH4 and are considered representative of tropospheric background conditions. The air samples were processed by isolation of CH4 from air and conversion to CO2 for isotopic analysis by isotope ratio mass spectrometry. These data represent one of the earliest records of 13C isotopic yy!measurements for atmospheric methane and have been used to refine estimates of CH4 emissions, calculate annual growth rates of emissions from changing sources, and provide evidence for changes in the rate of atmospheric removal of CH4. The data records consist of sample collection date; number of samples combined for analysis; sampling location; analysis date; CH4 concentration; 13C isotopic abundance; and flag codes to indicate outliers, repeated analyses, and other information.

Geostatistics and the representative elementary volume of gamma ray tomography attenuation in rocks cores

USGS Publications Warehouse

Vogel, J.R.; Brown, G.O.

2003-01-01

Semivariograms of samples of Culebra Dolomite have been determined at two different resolutions for gamma ray computed tomography images. By fitting models to semivariograms, small-scale and large-scale correlation lengths are determined for four samples. Different semivariogram parameters were found for adjacent cores at both resolutions. Relative elementary volume (REV) concepts are related to the stationarity of the sample. A scale disparity factor is defined and is used to determine sample size required for ergodic stationarity with a specified correlation length. This allows for comparison of geostatistical measures and representative elementary volumes. The modifiable areal unit problem is also addressed and used to determine resolution effects on correlation lengths. By changing resolution, a range of correlation lengths can be determined for the same sample. Comparison of voxel volume to the best-fit model correlation length of a single sample at different resolutions reveals a linear scaling effect. Using this relationship, the range of the point value semivariogram is determined. This is the range approached as the voxel size goes to zero. Finally, these results are compared to the regularization theory of point variables for borehole cores and are found to be a better fit for predicting the volume-averaged range.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hurley, D.F.; Whitehouse, J.M.

A dedicated low-flow groundwater sample collection system was designed for implementation in a post-closure ACL monitoring program at the Yaworski Lagoon NPL site in Canterbury, Connecticut. The system includes dedicated bladder pumps with intake ports located in the screened interval of the monitoring wells. This sampling technique was implemented in the spring of 1993. The system was designed to simultaneously obtain samples directly from the screened interval of nested wells in three distinct water bearing zones. Sample collection is begun upon stabilization of field parameters. Other than line volume, no prior purging of the well is required. It was foundmore » that dedicated low-flow sampling from the screened interval provides a method of representative sample collection without the bias of suspended solids introduced by traditional techniques of pumping and bailing. Analytical data indicate that measured chemical constituents are representative of groundwater migrating through the screened interval. Upon implementation of the low-flow monitoring system, analytical results exhibited a decrease in concentrations of some organic compounds and metals. The system has also proven to be a cost effective alternative to pumping and bailing which generate large volumes of purge water requiring containment and disposal.« less

The database of the PREDICTS (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems) project.

PubMed

Hudson, Lawrence N; Newbold, Tim; Contu, Sara; Hill, Samantha L L; Lysenko, Igor; De Palma, Adriana; Phillips, Helen R P; Alhusseini, Tamera I; Bedford, Felicity E; Bennett, Dominic J; Booth, Hollie; Burton, Victoria J; Chng, Charlotte W T; Choimes, Argyrios; Correia, David L P; Day, Julie; Echeverría-Londoño, Susy; Emerson, Susan R; Gao, Di; Garon, Morgan; Harrison, Michelle L K; Ingram, Daniel J; Jung, Martin; Kemp, Victoria; Kirkpatrick, Lucinda; Martin, Callum D; Pan, Yuan; Pask-Hale, Gwilym D; Pynegar, Edwin L; Robinson, Alexandra N; Sanchez-Ortiz, Katia; Senior, Rebecca A; Simmons, Benno I; White, Hannah J; Zhang, Hanbin; Aben, Job; Abrahamczyk, Stefan; Adum, Gilbert B; Aguilar-Barquero, Virginia; Aizen, Marcelo A; Albertos, Belén; Alcala, E L; Del Mar Alguacil, Maria; Alignier, Audrey; Ancrenaz, Marc; Andersen, Alan N; Arbeláez-Cortés, Enrique; Armbrecht, Inge; Arroyo-Rodríguez, Víctor; Aumann, Tom; Axmacher, Jan C; Azhar, Badrul; Azpiroz, Adrián B; Baeten, Lander; Bakayoko, Adama; Báldi, András; Banks, John E; Baral, Sharad K; Barlow, Jos; Barratt, Barbara I P; Barrico, Lurdes; Bartolommei, Paola; Barton, Diane M; Basset, Yves; Batáry, Péter; Bates, Adam J; Baur, Bruno; Bayne, Erin M; Beja, Pedro; Benedick, Suzan; Berg, Åke; Bernard, Henry; Berry, Nicholas J; Bhatt, Dinesh; Bicknell, Jake E; Bihn, Jochen H; Blake, Robin J; Bobo, Kadiri S; Bóçon, Roberto; Boekhout, Teun; Böhning-Gaese, Katrin; Bonham, Kevin J; Borges, Paulo A V; Borges, Sérgio H; Boutin, Céline; Bouyer, Jérémy; Bragagnolo, Cibele; Brandt, Jodi S; Brearley, Francis Q; Brito, Isabel; Bros, Vicenç; Brunet, Jörg; Buczkowski, Grzegorz; Buddle, Christopher M; Bugter, Rob; Buscardo, Erika; Buse, Jörn; Cabra-García, Jimmy; Cáceres, Nilton C; Cagle, Nicolette L; Calviño-Cancela, María; Cameron, Sydney A; Cancello, Eliana M; Caparrós, Rut; Cardoso, Pedro; Carpenter, Dan; Carrijo, Tiago F; Carvalho, Anelena L; Cassano, Camila R; Castro, Helena; Castro-Luna, Alejandro A; Rolando, Cerda B; Cerezo, Alexis; Chapman, Kim Alan; Chauvat, Matthieu; Christensen, Morten; Clarke, Francis M; Cleary, Daniel F R; Colombo, Giorgio; Connop, Stuart P; Craig, Michael D; Cruz-López, Leopoldo; Cunningham, Saul A; D'Aniello, Biagio; D'Cruze, Neil; da Silva, Pedro Giovâni; Dallimer, Martin; Danquah, Emmanuel; Darvill, Ben; Dauber, Jens; Davis, Adrian L V; Dawson, Jeff; de Sassi, Claudio; de Thoisy, Benoit; Deheuvels, Olivier; Dejean, Alain; Devineau, Jean-Louis; Diekötter, Tim; Dolia, Jignasu V; Domínguez, Erwin; Dominguez-Haydar, Yamileth; Dorn, Silvia; Draper, Isabel; Dreber, Niels; Dumont, Bertrand; Dures, Simon G; Dynesius, Mats; Edenius, Lars; Eggleton, Paul; Eigenbrod, Felix; Elek, Zoltán; Entling, Martin H; Esler, Karen J; de Lima, Ricardo F; Faruk, Aisyah; Farwig, Nina; Fayle, Tom M; Felicioli, Antonio; Felton, Annika M; Fensham, Roderick J; Fernandez, Ignacio C; Ferreira, Catarina C; Ficetola, Gentile F; Fiera, Cristina; Filgueiras, Bruno K C; Fırıncıoğlu, Hüseyin K; Flaspohler, David; Floren, Andreas; Fonte, Steven J; Fournier, Anne; Fowler, Robert E; Franzén, Markus; Fraser, Lauchlan H; Fredriksson, Gabriella M; Freire, Geraldo B; Frizzo, Tiago L M; Fukuda, Daisuke; Furlani, Dario; Gaigher, René; Ganzhorn, Jörg U; García, Karla P; Garcia-R, Juan C; Garden, Jenni G; Garilleti, Ricardo; Ge, Bao-Ming; Gendreau-Berthiaume, Benoit; Gerard, Philippa J; Gheler-Costa, Carla; Gilbert, Benjamin; Giordani, Paolo; Giordano, Simonetta; Golodets, Carly; Gomes, Laurens G L; Gould, Rachelle K; Goulson, Dave; Gove, Aaron D; Granjon, Laurent; Grass, Ingo; Gray, Claudia L; Grogan, James; Gu, Weibin; Guardiola, Moisès; Gunawardene, Nihara R; Gutierrez, Alvaro G; Gutiérrez-Lamus, Doris L; Haarmeyer, Daniela H; Hanley, Mick E; Hanson, Thor; Hashim, Nor R; Hassan, Shombe N; Hatfield, Richard G; Hawes, Joseph E; Hayward, Matt W; Hébert, Christian; Helden, Alvin J; Henden, John-André; Henschel, Philipp; Hernández, Lionel; Herrera, James P; Herrmann, Farina; Herzog, Felix; Higuera-Diaz, Diego; Hilje, Branko; Höfer, Hubert; Hoffmann, Anke; Horgan, Finbarr G; Hornung, Elisabeth; Horváth, Roland; Hylander, Kristoffer; Isaacs-Cubides, Paola; Ishida, Hiroaki; Ishitani, Masahiro; Jacobs, Carmen T; Jaramillo, Víctor J; Jauker, Birgit; Hernández, F Jiménez; Johnson, McKenzie F; Jolli, Virat; Jonsell, Mats; Juliani, S Nur; Jung, Thomas S; Kapoor, Vena; Kappes, Heike; Kati, Vassiliki; Katovai, Eric; Kellner, Klaus; Kessler, Michael; Kirby, Kathryn R; Kittle, Andrew M; Knight, Mairi E; Knop, Eva; Kohler, Florian; Koivula, Matti; Kolb, Annette; Kone, Mouhamadou; Kőrösi, Ádám; Krauss, Jochen; Kumar, Ajith; Kumar, Raman; Kurz, David J; Kutt, Alex S; Lachat, Thibault; Lantschner, Victoria; Lara, Francisco; Lasky, Jesse R; Latta, Steven C; Laurance, William F; Lavelle, Patrick; Le Féon, Violette; LeBuhn, Gretchen; Légaré, Jean-Philippe; Lehouck, Valérie; Lencinas, María V; Lentini, Pia E; Letcher, Susan G; Li, Qi; Litchwark, Simon A; Littlewood, Nick A; Liu, Yunhui; Lo-Man-Hung, Nancy; López-Quintero, Carlos A; Louhaichi, Mounir; Lövei, Gabor L; Lucas-Borja, Manuel Esteban; Luja, Victor H; Luskin, Matthew S; MacSwiney G, M Cristina; Maeto, Kaoru; Magura, Tibor; Mallari, Neil Aldrin; Malone, Louise A; Malonza, Patrick K; Malumbres-Olarte, Jagoba; Mandujano, Salvador; Måren, Inger E; Marin-Spiotta, Erika; Marsh, Charles J; Marshall, E J P; Martínez, Eliana; Martínez Pastur, Guillermo; Moreno Mateos, David; Mayfield, Margaret M; Mazimpaka, Vicente; McCarthy, Jennifer L; McCarthy, Kyle P; McFrederick, Quinn S; McNamara, Sean; Medina, Nagore G; Medina, Rafael; Mena, Jose L; Mico, Estefania; Mikusinski, Grzegorz; Milder, Jeffrey C; Miller, James R; Miranda-Esquivel, Daniel R; Moir, Melinda L; Morales, Carolina L; Muchane, Mary N; Muchane, Muchai; Mudri-Stojnic, Sonja; Munira, A Nur; Muoñz-Alonso, Antonio; Munyekenye, B F; Naidoo, Robin; Naithani, A; Nakagawa, Michiko; Nakamura, Akihiro; Nakashima, Yoshihiro; Naoe, Shoji; Nates-Parra, Guiomar; Navarrete Gutierrez, Dario A; Navarro-Iriarte, Luis; Ndang'ang'a, Paul K; Neuschulz, Eike L; Ngai, Jacqueline T; Nicolas, Violaine; Nilsson, Sven G; Noreika, Norbertas; Norfolk, Olivia; Noriega, Jorge Ari; Norton, David A; Nöske, Nicole M; Nowakowski, A Justin; Numa, Catherine; O'Dea, Niall; O'Farrell, Patrick J; Oduro, William; Oertli, Sabine; Ofori-Boateng, Caleb; Oke, Christopher Omamoke; Oostra, Vicencio; Osgathorpe, Lynne M; Otavo, Samuel Eduardo; Page, Navendu V; Paritsis, Juan; Parra-H, Alejandro; Parry, Luke; Pe'er, Guy; Pearman, Peter B; Pelegrin, Nicolás; Pélissier, Raphaël; Peres, Carlos A; Peri, Pablo L; Persson, Anna S; Petanidou, Theodora; Peters, Marcell K; Pethiyagoda, Rohan S; Phalan, Ben; Philips, T Keith; Pillsbury, Finn C; Pincheira-Ulbrich, Jimmy; Pineda, Eduardo; Pino, Joan; Pizarro-Araya, Jaime; Plumptre, A J; Poggio, Santiago L; Politi, Natalia; Pons, Pere; Poveda, Katja; Power, Eileen F; Presley, Steven J; Proença, Vânia; Quaranta, Marino; Quintero, Carolina; Rader, Romina; Ramesh, B R; Ramirez-Pinilla, Martha P; Ranganathan, Jai; Rasmussen, Claus; Redpath-Downing, Nicola A; Reid, J Leighton; Reis, Yana T; Rey Benayas, José M; Rey-Velasco, Juan Carlos; Reynolds, Chevonne; Ribeiro, Danilo Bandini; Richards, Miriam H; Richardson, Barbara A; Richardson, Michael J; Ríos, Rodrigo Macip; Robinson, Richard; Robles, Carolina A; Römbke, Jörg; Romero-Duque, Luz Piedad; Rös, Matthias; Rosselli, Loreta; Rossiter, Stephen J; Roth, Dana S; Roulston, T'ai H; Rousseau, Laurent; Rubio, André V; Ruel, Jean-Claude; Sadler, Jonathan P; Sáfián, Szabolcs; Saldaña-Vázquez, Romeo A; Sam, Katerina; Samnegård, Ulrika; Santana, Joana; Santos, Xavier; Savage, Jade; Schellhorn, Nancy A; Schilthuizen, Menno; Schmiedel, Ute; Schmitt, Christine B; Schon, Nicole L; Schüepp, Christof; Schumann, Katharina; Schweiger, Oliver; Scott, Dawn M; Scott, Kenneth A; Sedlock, Jodi L; Seefeldt, Steven S; Shahabuddin, Ghazala; Shannon, Graeme; Sheil, Douglas; Sheldon, Frederick H; Shochat, Eyal; Siebert, Stefan J; Silva, Fernando A B; Simonetti, Javier A; Slade, Eleanor M; Smith, Jo; Smith-Pardo, Allan H; Sodhi, Navjot S; Somarriba, Eduardo J; Sosa, Ramón A; Soto Quiroga, Grimaldo; St-Laurent, Martin-Hugues; Starzomski, Brian M; Stefanescu, Constanti; Steffan-Dewenter, Ingolf; Stouffer, Philip C; Stout, Jane C; Strauch, Ayron M; Struebig, Matthew J; Su, Zhimin; Suarez-Rubio, Marcela; Sugiura, Shinji; Summerville, Keith S; Sung, Yik-Hei; Sutrisno, Hari; Svenning, Jens-Christian; Teder, Tiit; Threlfall, Caragh G; Tiitsaar, Anu; Todd, Jacqui H; Tonietto, Rebecca K; Torre, Ignasi; Tóthmérész, Béla; Tscharntke, Teja; Turner, Edgar C; Tylianakis, Jason M; Uehara-Prado, Marcio; Urbina-Cardona, Nicolas; Vallan, Denis; Vanbergen, Adam J; Vasconcelos, Heraldo L; Vassilev, Kiril; Verboven, Hans A F; Verdasca, Maria João; Verdú, José R; Vergara, Carlos H; Vergara, Pablo M; Verhulst, Jort; Virgilio, Massimiliano; Vu, Lien Van; Waite, Edward M; Walker, Tony R; Wang, Hua-Feng; Wang, Yanping; Watling, James I; Weller, Britta; Wells, Konstans; Westphal, Catrin; Wiafe, Edward D; Williams, Christopher D; Willig, Michael R; Woinarski, John C Z; Wolf, Jan H D; Wolters, Volkmar; Woodcock, Ben A; Wu, Jihua; Wunderle, Joseph M; Yamaura, Yuichi; Yoshikura, Satoko; Yu, Douglas W; Zaitsev, Andrey S; Zeidler, Juliane; Zou, Fasheng; Collen, Ben; Ewers, Rob M; Mace, Georgina M; Purves, Drew W; Scharlemann, Jörn P W; Purvis, Andy

2017-01-01

The PREDICTS project-Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)-has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used this evidence base to develop global and regional statistical models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at over 26,000 locations and representing over 47,000 species. We outline how the database can help in answering a range of questions in ecology and conservation biology. To our knowledge, this is the largest and most geographically and taxonomically representative database of spatial comparisons of biodiversity that has been collated to date; it will be useful to researchers and international efforts wishing to model and understand the global status of biodiversity.

11,670 whole-genome sequences representative of the Han Chinese population from the CONVERGE project.

PubMed

Cai, Na; Bigdeli, Tim B; Kretzschmar, Warren W; Li, Yihan; Liang, Jieqin; Hu, Jingchu; Peterson, Roseann E; Bacanu, Silviu; Webb, Bradley Todd; Riley, Brien; Li, Qibin; Marchini, Jonathan; Mott, Richard; Kendler, Kenneth S; Flint, Jonathan

2017-02-14

The China, Oxford and Virginia Commonwealth University Experimental Research on Genetic Epidemiology (CONVERGE) project on Major Depressive Disorder (MDD) sequenced 11,670 female Han Chinese at low-coverage (1.7X), providing the first large-scale whole genome sequencing resource representative of the largest ethnic group in the world. Samples are collected from 58 hospitals from 23 provinces around China. We are able to call 22 million high quality single nucleotide polymorphisms (SNP) from the nuclear genome, representing the largest SNP call set from an East Asian population to date. We use these variants for imputation of genotypes across all samples, and this has allowed us to perform a successful genome wide association study (GWAS) on MDD. The utility of these data can be extended to studies of genetic ancestry in the Han Chinese and evolutionary genetics when integrated with data from other populations. Molecular phenotypes, such as copy number variations and structural variations can be detected, quantified and analysed in similar ways.

Minimum and Maximum Times Required to Obtain Representative Suspended Sediment Samples

NASA Astrophysics Data System (ADS)

Gitto, A.; Venditti, J. G.; Kostaschuk, R.; Church, M. A.

2014-12-01

Bottle sampling is a convenient method of obtaining suspended sediment measurements for the development of sediment budgets. While these methods are generally considered to be reliable, recent analysis of depth-integrated sampling has identified considerable uncertainty in measurements of grain-size concentration between grain-size classes of multiple samples. Point-integrated bottle sampling is assumed to represent the mean concentration of suspended sediment but the uncertainty surrounding this method is not well understood. Here we examine at-a-point variability in velocity, suspended sediment concentration, grain-size distribution, and grain-size moments to determine if traditional point-integrated methods provide a representative sample of suspended sediment. We present continuous hour-long observations of suspended sediment from the sand-bedded portion of the Fraser River at Mission, British Columbia, Canada, using a LISST laser-diffraction instrument. Spectral analysis suggests that there are no statistically significant peak in energy density, suggesting the absence of periodic fluctuations in flow and suspended sediment. However, a slope break in the spectra at 0.003 Hz corresponds to a period of 5.5 minutes. This coincides with the threshold between large-scale turbulent eddies that scale with channel width/mean velocity and hydraulic phenomena related to channel dynamics. This suggests that suspended sediment samples taken over a period longer than 5.5 minutes incorporate variability that is larger scale than turbulent phenomena in this channel. Examination of 5.5-minute periods of our time series indicate that ~20% of the time a stable mean value of volumetric concentration is reached within 30 seconds, a typical bottle sample duration. In ~12% of measurements a stable mean was not reached over the 5.5 minute sample duration. The remaining measurements achieve a stable mean in an even distribution over the intervening interval.

Napping-Ultra Flash Profile as a Tool for Category Identification and Subsequent Model System Formulation of Caramel Corn Products.

PubMed

Mayhew, Emily; Schmidt, Shelly; Lee, Soo-Yeun

2016-07-01

In a novel approach to formulation, the flash descriptive profiling technique Napping-Ultra Flash Profile (Napping-UFP) was used to characterize a wide range of commercial caramel corn products. The objectives were to identify product categories, develop model systems based on product categories, and correlate analytical parameters with sensory terms generated through the Napping-UFP exercise. In one 2 h session, 12 panelists participated in 4 Napping-UFP exercises, describing and grouping, on a 43×56 cm paper sheet, 12 commercial caramel corn samples by degree of similarity, globally and in terms of aroma-by-mouth, texture, and taste. The coordinates of each sample's placement on the paper sheet and descriptive terms generated by the panelists were used to conduct Multiple Factor Analysis (MFA) and hierarchical clustering of the samples. Strong trends in the clustering of samples across the 4 Napping-UFP exercises resulted in the determination of 3 overarching types of commercial caramel corn: "small-scale dark" (typified by burnt, rich caramel corn), "large-scale light" (typified by light and buttery caramel corn), and "large-scale dark" (typified by sweet and molasses-like caramel corn). Representative samples that best exemplified the properties of each category were used as guides in the formulation of 3 model systems that represent the spread of commercial caramel corn products. Analytical testing of the commercial products, including aw measurement, moisture content determination, and thermal characterization via differential scanning calorimetry, were conducted and results related to sensory descriptors using Spearman's correlation. © 2016 Institute of Food Technologists®

Field size, length, and width distributions based on LACIE ground truth data. [large area crop inventory experiment

NASA Technical Reports Server (NTRS)

Pitts, D. E.; Badhwar, G.

1980-01-01

The development of agricultural remote sensing systems requires knowledge of agricultural field size distributions so that the sensors, sampling frames, image interpretation schemes, registration systems, and classification systems can be properly designed. Malila et al. (1976) studied the field size distribution for wheat and all other crops in two Kansas LACIE (Large Area Crop Inventory Experiment) intensive test sites using ground observations of the crops and measurements of their field areas based on current year rectified aerial photomaps. The field area and size distributions reported in the present investigation are derived from a representative subset of a stratified random sample of LACIE sample segments. In contrast to previous work, the obtained results indicate that most field-size distributions are not log-normally distributed. The most common field size observed in this study was 10 acres for most crops studied.

Violent Lives: A Lifestyle Model Linking Exposure to Violence to Juvenile Violent Offending

ERIC Educational Resources Information Center

Nofziger, Stacey; Kurtz, Don

2005-01-01

Studies examining the consequences of juvenile exposure to violence focus largely on psychological outcomes and often ignore the ways in which exposure is associated with deviant peers and juvenile offending. Using data from the National Survey of Adolescents (NSA), a nationally representative sample of juveniles between the ages of 12 and 17, we…

Changes in Pell Grant Participation and Median Income of Recipients. Data Point. NCES 2016-407

ERIC Educational Resources Information Center

Ifill, Nicole; Velez, Erin Dunlop

2016-01-01

This report is based on data from four iterations of the National Postsecondary Student Aid Study (NPSAS), a large, nationally representative sample survey of students that focuses on how they finance their education. NPSAS includes data on federal Pell Grant awards, which are need-based grants awarded to low-income students, primarily…

Awareness and Use of Folic Acid among Women in the Lower Mississippi Delta

ERIC Educational Resources Information Center

Robbins, James M.; Hopkins, Sarah E.; Mosley, Bridget S.; Casey, Patrick H.; Cleves, Mario A.; Hobbs, Charlotte A.

2006-01-01

Context: National and state efforts to increase folic acid awareness and use may not be reaching large segments of the population. Purpose: This study examines folic acid awareness and use among women of childbearing age in a representative, economically at-risk rural sample and identifies factors that influence awareness and use. Methods: A…

Factors Associated with School Meal Participation and the Relationship between Different Participation Measures. Final Report

ERIC Educational Resources Information Center

Moore, Quinn; Hulsey, Lara; Ponza, Michael

2009-01-01

This report investigates three important aspects of National School Lunch Program (NSLP) and School Breakfast Program (SBP) participation using recently collected data on a large, nationally representative sample of students certified for free and reduced-price meals during the 2005-2006 school year. First, we examine the factors that influence…

The Requirement for Vocational Skills in the Engineering Industry in the Areas of Modena and Vienna. Synthesis Report.

ERIC Educational Resources Information Center

Gatti, Mario; Mereu, Maria Grazia; Tagliaferro, Claudio; Markowitsch, Jorg; Neuberger, Robert

Requirements for vocational skills in the engineering industry in Modena, Italy, and Vienna, Austria, were studied. In Modena, employees of a representative sample of 90 small, medium, and large firms in the mechanical processing, agricultural machinery, and sports car manufacturing sectors were interviewed. In Vienna, data were collected through…

Differences in Access to Care among Students Using School-Based Health Centers

ERIC Educational Resources Information Center

Parasuraman, Sarika Rane; Shi, Leiyu

2015-01-01

Health care reform has changed the landscape for the nation's health safety net, and school-based health centers (SBHCs) remain an important part of this system. However, few large-scale studies have been conducted to assess their impact on access to care. This study investigated differences in access among a nationally representative sample of…

Sources of Score Scale Inconsistency. Research Report. ETS RR-11-10

ERIC Educational Resources Information Center

Haberman, Shelby J.; Dorans, Neil J.

2011-01-01

For testing programs that administer multiple forms within a year and across years, score equating is used to ensure that scores can be used interchangeably. In an ideal world, samples sizes are large and representative of populations that hardly change over time, and very reliable alternate test forms are built with nearly identical psychometric…

Modeling Nonignorable Missing Data with Item Response Theory (IRT). Research Report. ETS RR-10-11

ERIC Educational Resources Information Center

Rose, Norman; von Davier, Matthias; Xu, Xueli

2010-01-01

Large-scale educational surveys are low-stakes assessments of educational outcomes conducted using nationally representative samples. In these surveys, students do not receive individual scores, and the outcome of the assessment is inconsequential for respondents. The low-stakes nature of these surveys, as well as variations in average performance…

Self-Reported Use of Different Forms of Aggression in Late Adolescence and Emerging Adulthood

ERIC Educational Resources Information Center

Verona, Edelyn; Sadeh, Naomi; Case, Steve M.; Reed, Americus, II; Bhattacharjee, Amit

2008-01-01

Two studies investigated the psychometric properties of a self-report measure of commonly recognized forms of aggression (FOA) that could be used to efficiently gather aggression data in large samples. EFA and CFA in Study 1 suggested that a five-factor model (Physical, Property, Verbal, Relational, and Passive-Rational) best represented the data…

School Climate and Dropping Out of School in the Era of Accountability

ERIC Educational Resources Information Center

Kotok, Stephen; Ikoma, Sakiko; Bodovski, Katerina

2016-01-01

Using data from the High School Longitudinal Study of 2009 (HSLS:09)--a large nationally representative sample of US high school students--we employed multilevel structural equation modeling (SEM) to examine the relationship between school characteristics and the likelihood that a student will drop out of high school. We used a multifaceted…

Diversity of Participation in Children with Cerebral Palsy

ERIC Educational Resources Information Center

Imms, Christine; Reilly, Sheena; Carlin, John; Dodd, Karen

2008-01-01

The aim of this study was to investigate the participation of children with cerebral palsy (CP) in activities outside school and to compare their participation with a large representative sample of children. A population-based survey was conducted of children with CP born in Victoria, Australia in 1994 and 1995. Of 219 living children identified,…

Autism Spectrum Disorders as a Qualitatively Distinct Category from Typical Behavior in a Large, Clinically Ascertained Sample

ERIC Educational Resources Information Center

Frazier, Thomas W.; Youngstrom, Eric A.; Sinclair, Leslie; Kubu, Cynthia S.; Law, Paul; Rezai, Ali; Constantino, John N.; Eng, Charis

2010-01-01

The present study evaluated the hypothesis that autism spectrum disorders (ASDs) are best represented as a discrete category distinct from typical behavior within autism-affected families. The latent structure, categorical versus dimensional, of ASDs informs future diagnostic revisions, clinical assessment, and the design of future research. Data…

Social Status, Cognitive Ability, and Educational Attainment as Predictors of Liberal Social Attitudes and Political Trust

ERIC Educational Resources Information Center

Schoon, Ingrid; Cheng, Helen; Gale, Catharine R.; Batty, G. David; Deary, Ian J.

2010-01-01

We examined the prospective associations between family socio-economic background, childhood intelligence ("g") at age 11, educational and occupational attainment, and social attitudes at age 33 in a large (N = 8804), representative sample of the British population born in 1958. Structural equation Modeling identified a latent trait of…

Racial, Ethnic, and Gender Differences in School Discipline among U.S. High School Students: 1991-2005

ERIC Educational Resources Information Center

Wallace, John M., Jr.; Goodkind, Sara; Wallace, Cynthia M.; Bachman, Jerald G.

2008-01-01

Large nationally representative samples of White, Black, Hispanic, Asian American, and American Indian students were used in this study to examine current patterns and recent trends in racial, ethnic, and gender differences in school discipline from 1991 to 2005. Findings revealed that Black, Hispanic, and American Indian youth are slightly more…

Undergraduates Who Do Not Apply for Financial Aid. Data Point. NCES 2016-406

ERIC Educational Resources Information Center

Ifill, Nicole

2016-01-01

This report is based on data from the 2011-12 National Postsecondary Student Aid Study (NPSAS:12), a large, nationally representative sample survey of students that focuses on how they finance their education. NPSAS includes data on the application for and receipt of financial aid, including grants, loans, assistantships, scholarships,…

Academic Self-Concept and Achievement in Polish Primary Schools: Cross-Lagged Modelling and Gender-Specific Effects

ERIC Educational Resources Information Center

Grygiel, Pawel; Modzelewski, Michal; Pisarek, Jolanta

2017-01-01

This study reports relationships between general academic self-concept and achievement in grade 3 and grade 5. Gender-specific effects were investigated using a longitudinal, two-cycle, 3-year autoregressive cross-lagged panel design in a large, representative sample of Polish primary school pupils (N = 4,226). Analysis revealed (a) reciprocal…

Sex Differences in Cognitive Abilities Test Scores: A UK National Picture

ERIC Educational Resources Information Center

Strand, Steve; Deary, Ian J.; Smith, Pauline

2006-01-01

Background and aims: There is uncertainty about the extent or even existence of sex differences in the mean and variability of reasoning test scores ( Jensen, 1998; Lynn, 1994, ; Mackintosh, 1996). This paper analyses the Cognitive Abilities Test (CAT) scores of a large and representative sample of UK pupils to determine the extent of any sex…

The Role of Callous and Unemotional Traits in the Diagnosis of Conduct Disorder

ERIC Educational Resources Information Center

Rowe, Richard; Maughan, Barbara; Moran, Paul; Ford, Tamsin; Briskman, Jackie; Goodman, Robert

2010-01-01

Background: Callous and unemotional (CU) traits might usefully subtype DSM-IV conduct disorder (CD). We investigate this hypothesis in a large, nationally representative sample of 5-16-year-olds. We also examine the characteristics of children with high CU traits but without CD. Methods: Data come from the 2004 British Child and Adolescent Mental…

Relations between Measures of Cattell-Horn-Carroll (CHC) Cognitive Abilities and Mathematics Achievement across the School-Age Years

ERIC Educational Resources Information Center

Floyd, Randy G.; Evans, Jeffrey J.; McGrew, Kevin S.

2003-01-01

Cognitive clusters from the Woodcock-Johnson III (WJ III) Tests of Cognitive Abilities that measure select Cattell-Horn-Carroll broad and narrow cognitive abilities were shown to be significantly related to mathematics achievement in a large, nationally representative sample of children and adolescents. Multiple regression analyses were used to…

Naming Problems Do Not Reflect a Second Independent Core Deficit in Dyslexia: Double Deficits Explored

ERIC Educational Resources Information Center

Vaessen, Anniek; Gerretsen, Patty; Blomert, Leo

2009-01-01

The double deficit hypothesis states that naming speed problems represent a second core deficit in dyslexia independent from a phonological deficit. The current study investigated the main assumptions of this hypothesis in a large sample of well-diagnosed dyslexics. The three main findings were that (a) naming speed was consistently related only…

Nursing Home Staff Turnover: Impact on Nursing Home Compare Quality Measures

ERIC Educational Resources Information Center

Castle, Nicholas G.; Engberg, John; Men, Aiju

2007-01-01

Purpose: We used data from a large sample of nursing homes to examine the association between staff turnover and quality. Design and Methods: The staff turnover measures came from primary data collected from 2,840 nursing homes in 2004 (representing a 71% response rate). Data collection included measures for nurse aides, licensed practical nurses,…

GenoCore: A simple and fast algorithm for core subset selection from large genotype datasets.

PubMed

Jeong, Seongmun; Kim, Jae-Yoon; Jeong, Soon-Chun; Kang, Sung-Taeg; Moon, Jung-Kyung; Kim, Namshin

2017-01-01

Selecting core subsets from plant genotype datasets is important for enhancing cost-effectiveness and to shorten the time required for analyses of genome-wide association studies (GWAS), and genomics-assisted breeding of crop species, etc. Recently, a large number of genetic markers (>100,000 single nucleotide polymorphisms) have been identified from high-density single nucleotide polymorphism (SNP) arrays and next-generation sequencing (NGS) data. However, there is no software available for picking out the efficient and consistent core subset from such a huge dataset. It is necessary to develop software that can extract genetically important samples in a population with coherence. We here present a new program, GenoCore, which can find quickly and efficiently the core subset representing the entire population. We introduce simple measures of coverage and diversity scores, which reflect genotype errors and genetic variations, and can help to select a sample rapidly and accurately for crop genotype dataset. Comparison of our method to other core collection software using example datasets are performed to validate the performance according to genetic distance, diversity, coverage, required system resources, and the number of selected samples. GenoCore selects the smallest, most consistent, and most representative core collection from all samples, using less memory with more efficient scores, and shows greater genetic coverage compared to the other software tested. GenoCore was written in R language, and can be accessed online with an example dataset and test results at https://github.com/lovemun/Genocore.

Environmental Monitoring and Assessment Program Western Pilot Project - Information about selected fish and macroinvertebrates sampled from North Dakota perennial streams, 2000-2003

USGS Publications Warehouse

Vining, Kevin C.; Lundgren, Robert F.

2008-01-01

Sixty-five sampling sites, selected by a statistical design to represent lengths of perennial streams in North Dakota, were chosen to be sampled for fish and aquatic insects (macroinvertebrates) to establish unbiased baseline data. Channel catfish and common carp were the most abundant game and large fish species in the Cultivated Plains and Rangeland Plains, respectively. Blackflies were present in more than 50 percent of stream lengths sampled in the State; mayflies and caddisflies were present in more than 80 percent. Dragonflies were present in a greater percentage of stream lengths in the Rangeland Plains than in the Cultivated Plains.

Collecting cometary soil samples? Development of the ROSETTA sample acquisition system

NASA Technical Reports Server (NTRS)

Coste, P. A.; Fenzi, M.; Eiden, Michael

1993-01-01

In the reference scenario of the ROSETTA CNRS mission, the Sample Acquisition System is mounted on the Comet Lander. Its tasks are to acquire three kinds of cometary samples and to transfer them to the Earth Return Capsule. Operations are to be performed in vacuum and microgravity, on a probably rough and dusty surface, in a largely unknown material, at temperatures in the order of 100 K. The concept and operation of the Sample Acquisition System are presented. The design of the prototype corer and surface sampling tool, and of the equipment for testing them at cryogenic temperatures in ambient conditions and in vacuum in various materials representing cometary soil, are described. Results of recent preliminary tests performed in low temperature thermal vacuum in a cometary analog ice-dust mixture are provided.

Representative Elementary Length to Measure Soil Mass Attenuation Coefficient

PubMed Central

Borges, J. A. R.; Pires, L. F.; Costa, J. C.

2014-01-01

With increasing demand for better yield in agricultural areas, soil physical property representative measurements are more and more essential. Nuclear techniques such as computerized tomography (CT) and gamma-ray attenuation (GAT) have been widely employed with this purpose. The soil mass attenuation coefficient (μ s) is an important parameter for CT and GAT analysis. When experimentally determined (μ es), the use of suitable sized samples enable to evaluate it precisely, as well as to reduce measurement time and costs. This study investigated the representative elementary length (REL) of sandy and clayey soils for μ es measurements. Two radioactive sources were employed (241Am and 137Cs), three collimators (2–4 mm diameters), and 14 thickness (x) samples (2–15 cm). Results indicated ideal thickness intervals of 12–15 and 2–4 cm for the sources 137Cs and 241Am, respectively. The application of such results in representative elementary area (REA) evaluations in clayey soil clods via CT indicated that μ es average values obtained for x > 4 cm and source 241Am might induce to the use of samples which are not large enough for soil bulk density evaluations (ρ s). As a consequence, ρ s might be under- or overestimated, generating inaccurate conclusions about the physical quality of the soil under study. PMID:24672338

Semi-Supervised Projective Non-Negative Matrix Factorization for Cancer Classification.

PubMed

Zhang, Xiang; Guan, Naiyang; Jia, Zhilong; Qiu, Xiaogang; Luo, Zhigang

2015-01-01

Advances in DNA microarray technologies have made gene expression profiles a significant candidate in identifying different types of cancers. Traditional learning-based cancer identification methods utilize labeled samples to train a classifier, but they are inconvenient for practical application because labels are quite expensive in the clinical cancer research community. This paper proposes a semi-supervised projective non-negative matrix factorization method (Semi-PNMF) to learn an effective classifier from both labeled and unlabeled samples, thus boosting subsequent cancer classification performance. In particular, Semi-PNMF jointly learns a non-negative subspace from concatenated labeled and unlabeled samples and indicates classes by the positions of the maximum entries of their coefficients. Because Semi-PNMF incorporates statistical information from the large volume of unlabeled samples in the learned subspace, it can learn more representative subspaces and boost classification performance. We developed a multiplicative update rule (MUR) to optimize Semi-PNMF and proved its convergence. The experimental results of cancer classification for two multiclass cancer gene expression profile datasets show that Semi-PNMF outperforms the representative methods.

Discriminant WSRC for Large-Scale Plant Species Recognition.

PubMed

Zhang, Shanwen; Zhang, Chuanlei; Zhu, Yihai; You, Zhuhong

2017-01-01

In sparse representation based classification (SRC) and weighted SRC (WSRC), it is time-consuming to solve the global sparse representation problem. A discriminant WSRC (DWSRC) is proposed for large-scale plant species recognition, including two stages. Firstly, several subdictionaries are constructed by dividing the dataset into several similar classes, and a subdictionary is chosen by the maximum similarity between the test sample and the typical sample of each similar class. Secondly, the weighted sparse representation of the test image is calculated with respect to the chosen subdictionary, and then the leaf category is assigned through the minimum reconstruction error. Different from the traditional SRC and its improved approaches, we sparsely represent the test sample on a subdictionary whose base elements are the training samples of the selected similar class, instead of using the generic overcomplete dictionary on the entire training samples. Thus, the complexity to solving the sparse representation problem is reduced. Moreover, DWSRC is adapted to newly added leaf species without rebuilding the dictionary. Experimental results on the ICL plant leaf database show that the method has low computational complexity and high recognition rate and can be clearly interpreted.

Resource allocation in NHS dentistry: recognition of societal preferences (RAINDROP): study protocol.

PubMed

Vernazza, Christopher R; Carr, Katherine; Wildman, John; Gray, Joanne; Holmes, Richard D; Exley, Catherine; Smith, Robert A; Donaldson, Cam

2018-06-22

Resources in any healthcare systems are scarce relative to need and therefore choices need to be made which often involve difficult decisions about the best allocation of these resources. One pragmatic and robust tool to aid resource allocation is Programme Budgeting and Marginal Analysis (PBMA), but there is mixed evidence on its uptake and effectiveness. Furthermore, there is also no evidence on the incorporation of the preferences of a large and representative sample of the general public into such a process. The study therefore aims to undertake, evaluate and refine a PBMA process within the exemplar of NHS dentistry in England whilst also using an established methodology (Willingness to Pay (WTP)) to systematically gather views from a representative sample of the public. Stakeholders including service buyers (commissioners), dentists, dental public health representatives and patient representatives will be recruited to participate in a PBMA process involving defining current spend, agreeing criteria to judge services/interventions, defining areas for investment and disinvestment, rating these areas against the criteria and making final recommendations. The process will be refined based on participatory action research principles and evaluated through semi-structured interviews, focus groups and observation of the process by the research team. In parallel a representative sample of English adults will be recruited to complete a series of four surveys including WTP valuations of programmes being considered by the PBMA panel. In addition a methodological experiment comparing two ways of eliciting WTP will be undertaken. The project will allow the PBMA process and particularly the use of WTP within it to be investigated and developed. There will be challenges around engagement with the task by the panel undertaking it and with the outputs by stakeholders but careful relationship building will help to mitigate this. The large volume of data will be managed through careful segmenting of the analysis and the use of the well-established Framework approach to qualitative data analysis. WTP has various potential biases but the elicitation will be carefully designed to minimise these and some methodological investigation will take place.

The production of multiprotein complexes in insect cells using the baculovirus expression system.

PubMed

Abdulrahman, Wassim; Radu, Laura; Garzoni, Frederic; Kolesnikova, Olga; Gupta, Kapil; Osz-Papai, Judit; Berger, Imre; Poterszman, Arnaud

2015-01-01

The production of a homogeneous protein sample in sufficient quantities is an essential prerequisite not only for structural investigations but represents also a rate-limiting step for many functional studies. In the cell, a large fraction of eukaryotic proteins exists as large multicomponent assemblies with many subunits, which act in concert to catalyze specific activities. Many of these complexes cannot be obtained from endogenous source material, so recombinant expression and reconstitution are then required to overcome this bottleneck. This chapter describes current strategies and protocols for the efficient production of multiprotein complexes in large quantities and of high quality, using the baculovirus/insect cell expression system.

Association between Early Marriage and Intimate Partner Violence in India: A Focus on Youth from Bihar and Rajasthan

PubMed Central

Speizer, Ilene S.; Pearson, Erin

2013-01-01

The relationship between intimate partner violence (IPV) and early marriage is explored using the 2005-2006 India National Family Health Survey (NFHS-3). The NFHS-3 collected data from a representative sample of women and men in India with a large enough sample size to have a representative sample at the state level. The focus is on youth from Bihar and Rajasthan, two states with high IPV and early marriage. Multivariate logistic regression analyses demonstrate that women ages 20-24 who married before age eighteen, the legal age at marriage in India, are more likely to have ever experienced IPV in their lifetime and recently experienced IPV (in the last 12 months) than their counterparts who married later. The results were significant in Rajasthan but not in Bihar. To reduce IPV, targeted efforts must be made to decrease the proportion of India’s girls who are married under the legal age of marriage. PMID:20587462

Comparative Analysis of Recruitment Strategies in a Study of Men Who Have Sex with Men (MSM) in Metropolitan Detroit.

PubMed

Iott, Bradley E; Veinot, Tiffany C; Loveluck, Jimena; Kahle, Erin; Golson, Leon; Benton, Akilah

2018-02-22

HIV/AIDS-related research requires recruitment of representative samples of MSM; yet, we know little about the comparative yield, diversity and cost-benefit tradeoffs between different recruitment venues. We compared 11 recruitment venues used for nine HIV prevention-related focus groups with MSM in Metropolitan Detroit. Of the 64 participants, 24 were clients recruited via an HIV/AIDS-focused nonprofit, 20 from Grindr advertisements, 6 from university-student email lists, and 5 from flyers/palmcards. Significantly more African-American, low-income and HIV-positive participants were recruited via the nonprofit. The best cost-benefit tradeoffs were for organizational Facebook posts, email groups, personal networking, and nonprofit recruitment. Grindr increased the size of the sample, though at greater expense. Facebook and Scruff advertisements and gay bar outreach represented greater costs than benefits. Only 11.6% of Grindr respondents attended the focus groups. A mix of online and offline recruitment venues can generate a large and diverse sample of MSM, but venue performance is uneven.

Validation sampling can reduce bias in health care database studies: an illustration using influenza vaccination effectiveness.

PubMed

Nelson, Jennifer Clark; Marsh, Tracey; Lumley, Thomas; Larson, Eric B; Jackson, Lisa A; Jackson, Michael L

2013-08-01

Estimates of treatment effectiveness in epidemiologic studies using large observational health care databases may be biased owing to inaccurate or incomplete information on important confounders. Study methods that collect and incorporate more comprehensive confounder data on a validation cohort may reduce confounding bias. We applied two such methods, namely imputation and reweighting, to Group Health administrative data (full sample) supplemented by more detailed confounder data from the Adult Changes in Thought study (validation sample). We used influenza vaccination effectiveness (with an unexposed comparator group) as an example and evaluated each method's ability to reduce bias using the control time period before influenza circulation. Both methods reduced, but did not completely eliminate, the bias compared with traditional effectiveness estimates that do not use the validation sample confounders. Although these results support the use of validation sampling methods to improve the accuracy of comparative effectiveness findings from health care database studies, they also illustrate that the success of such methods depends on many factors, including the ability to measure important confounders in a representative and large enough validation sample, the comparability of the full sample and validation sample, and the accuracy with which the data can be imputed or reweighted using the additional validation sample information. Copyright © 2013 Elsevier Inc. All rights reserved.

Validation sampling can reduce bias in healthcare database studies: an illustration using influenza vaccination effectiveness

PubMed Central

Nelson, Jennifer C.; Marsh, Tracey; Lumley, Thomas; Larson, Eric B.; Jackson, Lisa A.; Jackson, Michael

2014-01-01

Objective Estimates of treatment effectiveness in epidemiologic studies using large observational health care databases may be biased due to inaccurate or incomplete information on important confounders. Study methods that collect and incorporate more comprehensive confounder data on a validation cohort may reduce confounding bias. Study Design and Setting We applied two such methods, imputation and reweighting, to Group Health administrative data (full sample) supplemented by more detailed confounder data from the Adult Changes in Thought study (validation sample). We used influenza vaccination effectiveness (with an unexposed comparator group) as an example and evaluated each method’s ability to reduce bias using the control time period prior to influenza circulation. Results Both methods reduced, but did not completely eliminate, the bias compared with traditional effectiveness estimates that do not utilize the validation sample confounders. Conclusion Although these results support the use of validation sampling methods to improve the accuracy of comparative effectiveness findings from healthcare database studies, they also illustrate that the success of such methods depends on many factors, including the ability to measure important confounders in a representative and large enough validation sample, the comparability of the full sample and validation sample, and the accuracy with which data can be imputed or reweighted using the additional validation sample information. PMID:23849144

Ion microprobe mass analysis of plagioclase from 'non-mare' lunar samples

NASA Technical Reports Server (NTRS)

Meyer, C., Jr.; Anderson, D. H.; Bradley, J. G.

1974-01-01

The ion microprobe was used to measure the composition and distribution of trace elements in lunar plagioclase, and these analyses are used as criteria in determining the possible origins of some nonmare lunar samples. The Apollo 16 samples with metaclastic texture and high-bulk trace-element contents contain plagioclase clasts with extremely low trace-element contents. These plagioclase inclusions represent unequilibrated relicts of anorthositic, noritic, or troctolitic rocks that have been intermixed as a rock flour into the KREEP-rich matrix of these samples. All of the plagioclase-rich inclusions which were analyzed in the KREEP-rich Apollo 14 breccias were found to be rich in trace elements. This does not seem to be consistent with the interpretation that the Apollo 14 samples represent a pre-Imbrium regolith, because such an ancient regolith should have contained many plagioclase clasts with low trace-element contents more typical of plagioclase from the pre-Imbrium crust. Ion-microprobe analyses for Ba and Sr in large plagioclase phenocrysts in 14310 and 68415 are consistent with the bulk compositions of these rocks and with the known distribution coefficients for these elements. The distribution coefficient for Li (basaltic liquid/plagioclase) was measured to be about 2.

Probabilistic #D data fusion for multiresolution surface generation

NASA Technical Reports Server (NTRS)

Manduchi, R.; Johnson, A. E.

2002-01-01

In this paper we present an algorithm for adaptive resolution integration of 3D data collected from multiple distributed sensors. The input to the algorithm is a set of 3D surface points and associated sensor models. Using a probabilistic rule, a surface probability function is generated that represents the probability that a particular volume of space contains the surface. The surface probability function is represented using an octree data structure; regions of space with samples of large conariance are stored at a coarser level than regions of space containing samples with smaller covariance. The algorithm outputs an adaptive resolution surface generated by connecting points that lie on the ridge of surface probability with triangles scaled to match the local discretization of space given by the algorithm, we present results from 3D data generated by scanning lidar and structure from motion.

Diversity and Genome Analysis of Australian and Global Oilseed Brassica napus L. Germplasm Using Transcriptomics and Whole Genome Re-sequencing.

PubMed

Malmberg, M Michelle; Shi, Fan; Spangenberg, German C; Daetwyler, Hans D; Cogan, Noel O I

2018-01-01

Intensive breeding of Brassica napus has resulted in relatively low diversity, such that B. napus would benefit from germplasm improvement schemes that sustain diversity. As such, samples representative of global germplasm pools need to be assessed for existing population structure, diversity and linkage disequilibrium (LD). Complexity reduction genotyping-by-sequencing (GBS) methods, including GBS-transcriptomics (GBS-t), enable cost-effective screening of a large number of samples, while whole genome re-sequencing (WGR) delivers the ability to generate large numbers of unbiased genomic single nucleotide polymorphisms (SNPs), and identify structural variants (SVs). Furthermore, the development of genomic tools based on whole genomes representative of global oilseed diversity and orientated by the reference genome has substantial industry relevance and will be highly beneficial for canola breeding. As recent studies have focused on European and Chinese varieties, a global diversity panel as well as a substantial number of Australian spring types were included in this study. Focusing on industry relevance, 633 varieties were initially genotyped using GBS-t to examine population structure using 61,037 SNPs. Subsequently, 149 samples representative of global diversity were selected for WGR and both data sets used for a side-by-side evaluation of diversity and LD. The WGR data was further used to develop genomic resources consisting of a list of 4,029,750 high-confidence SNPs annotated using SnpEff, and SVs in the form of 10,976 deletions and 2,556 insertions. These resources form the basis of a reliable and repeatable system allowing greater integration between canola genomics studies, with a strong focus on breeding germplasm and industry applicability.

A method for development of a system of identification for Appalachian coal-bearing rocks

USGS Publications Warehouse

Ferm, J.C.; Weisenfluh, G.A.; Smith, G.C.

2002-01-01

The number of observable properties of sedimentary rocks is large and numerous classifications have been proposed for describing them. Some rock classifications, however, may be disadvantageous in situations such as logging rock core during coal exploration programs, where speed and simplicity are the essence. After experimenting with a number of formats for logging rock core in the Appalachian coal fields, a method of using color photographs accompanied by a rock name and numeric code was selected. In order to generate a representative collection of rocks to be photographed, sample methods were devised to produce a representative collection, and empirically based techniques were devised to identify repeatedly recognizable rock types. A number of cores representing the stratigraphic and geographic range of the region were sampled so that every megascopically recognizable variety was included in the collection; the frequency of samples of any variety reflects the frequency with which it would be encountered during logging. In order to generate repeatedly recognizable rock classes, the samples were sorted to display variation in grain size, mineral composition, color, and sedimentary structures. Class boundaries for each property were selected on the basis of existing, widely accepted limits and the precision with which these limits could be recognized. The process of sorting the core samples demonstrated relationships between rock properties and indicated that similar methods, applied to other groups of rocks, could yield more widely applicable field classifications. ?? 2002 Elsevier Science B.V. All rights reserved.

"Under the radar": nurse practitioner prescribers and pharmaceutical industry promotions.

PubMed

Ladd, Elissa C; Mahoney, Diane Feeney; Emani, Srinivas

2010-12-01

To assess nurse practitioners' interactions with pharmaceutical industry promotional activities and their perception of information reliability and self-reported prescribing behaviors. Self-administered online survey. A nationally randomized sample of nurse practitioner prescribers was surveyed. Eligibility criteria included current clinical practice and licensure to prescribe medications in their state of practice. A total of 263 responses were analyzed. Almost all respondents (96%) reported regular contact with pharmaceutical sales representatives, and most (71%) reported receiving information on new drugs directly from pharmaceutical sales representatives some or most of the time. A large portion (66%) dispensed drug samples regularly to their patients, and 73% believed that samples were somewhat or very helpful in learning about new drugs. Eighty-one percent of respondents thought that it was ethically acceptable to give out samples to anyone, and 90% believed that it was acceptable to attend lunch and dinner events sponsored by the pharmaceutical industry. Almost half (48%) stated that they were more likely to prescribe a drug that was highlighted during a lunch or dinner event. Most respondents stated that it was ethically acceptable for speakers to be paid by industry. Nurse practitioner prescribers had extensive contact with pharmaceutical industry promotional activities such as pharmaceutical representative contact, receipt of drug samples, and regular attendance at industry-sponsored meal events and continuing education programs. They reported that industry interface with nurse practitioner prescribers in the form of sponsored meals, education events, and paid speakers was ethically acceptable.

Nearest neighbor density ratio estimation for large-scale applications in astronomy

NASA Astrophysics Data System (ADS)

Kremer, J.; Gieseke, F.; Steenstrup Pedersen, K.; Igel, C.

2015-09-01

In astronomical applications of machine learning, the distribution of objects used for building a model is often different from the distribution of the objects the model is later applied to. This is known as sample selection bias, which is a major challenge for statistical inference as one can no longer assume that the labeled training data are representative. To address this issue, one can re-weight the labeled training patterns to match the distribution of unlabeled data that are available already in the training phase. There are many examples in practice where this strategy yielded good results, but estimating the weights reliably from a finite sample is challenging. We consider an efficient nearest neighbor density ratio estimator that can exploit large samples to increase the accuracy of the weight estimates. To solve the problem of choosing the right neighborhood size, we propose to use cross-validation on a model selection criterion that is unbiased under covariate shift. The resulting algorithm is our method of choice for density ratio estimation when the feature space dimensionality is small and sample sizes are large. The approach is simple and, because of the model selection, robust. We empirically find that it is on a par with established kernel-based methods on relatively small regression benchmark datasets. However, when applied to large-scale photometric redshift estimation, our approach outperforms the state-of-the-art.

Instrument to collect fogwater for chemical analysis

NASA Astrophysics Data System (ADS)

Jacob, Daniel J.; Waldman, Jed M.; Haghi, Mehrdad; Hoffmann, Michael R.; Flagan, Richard C.

1985-06-01

An instrument is presented which collects large samples of ambient fogwater by impaction of droplets on a screen. The collection efficiency of the instrument is determined as a function of droplet size, and it is shown that fog droplets in the range 3-100-μm diameter are efficiently collected. No significant evaporation or condensation occurs at any stage of the collection process. Field testing indicates that samples collected are representative of the ambient fogwater. The instrument may easily be automated, and is suitable for use in routine air quality monitoring programs.

Application of laboratory permeability data

USGS Publications Warehouse

Johnson, A.I.

1963-01-01

Some of the basic material contained in this report originally was prepared in 1952 as instructional handouts for ground-water short courses and for training of foreign participants. The material has been revised and expanded and is presented in the present form to make it more readily available to the field hydrologist. Illustrations now present published examples of the applications suggested in the 1952 material. For small areas, a field pumping test is sufficient to predict the characteristics of an aquifer. With a large area under study, the aquifer properties must be determined at many different locations and it is not usually economically feasible to make sufficient field tests to define the aquifer properties in detail for the whole aquifer. By supplementing a few field tests with laboratory permeability data and geologic interpretation, more point measurements representative of the hydrologic properties of the aquifer may be obtained. A sufficient number of samples seldom can be obtained to completely identify the permeability or transmissibility in detail for a project area. However, a few judiciously chosen samples of high quality, combined with good geologic interpretation, often will permit the extrapolation of permeability information over a large area with a fair degree of reliability. The importance of adequate geologic information, as well as the importance of collecting samples representative of at least all major textural units lying within the section or area of study, cannot be overemphasized.

The Big Fish Down Under: Examining Moderators of the "Big-Fish-Little-Pond" Effect for Australia's High Achievers

ERIC Educational Resources Information Center

Seaton, Marjorie; Marsh, Herbert W.; Yeung, Alexander Seeshing; Craven, Rhonda

2011-01-01

Big-fish-little-pond effect (BFLPE) research has demonstrated that academic self-concept is negatively affected by attending high-ability schools. This article examines data from large, representative samples of 15-year-olds from each Australian state, based on the three Program for International Student Assessment (PISA) databases that focus on…

User Requirements in Identifying Desired Works in a Large Library. Final Report.

ERIC Educational Resources Information Center

Lipetz, Ben-Ami

Utilization of the card catalog in the main library (Sterling Memorial Library) of Yale University was studied over a period of more than a year. Traffic flow in the catalog was observed, and was used as the basis for scheduling interviews with a representative sample of catalog users at the moment of catalog use. More than 2000 interviews were…

Does the public notice visual resource problems on the federal estate?

Treesearch

John D. Peine

1979-01-01

Results of the 1977 Federal estate are highlighted. The survey of recreation on the Federal estate represents a unique data set which was uniformly collected across all Federal land managing agencies and sections of the country. The on-site sampling procedures utilized in this survey process have never before been applied on such a large scale. Procedures followed and...

Communities of Practice for the Development of Adolescent Civic Engagement: An Empirical Study of Their Correlates in Australia and the United States

ERIC Educational Resources Information Center

Homana, Gary A.

2009-01-01

The relationships between a multidimensional model of school community and civic engagement were examined using survey data collected for the 1999 IEA Civic Education Study from large, nationally representative samples of adolescents in Australia and the United States. This study extends previous research by considering the extent to which…

Substance Abuse and Behavioral Correlates of Sexual Assault among South African Adolescents

ERIC Educational Resources Information Center

King, Gary; Flisher, Alan, J.; Noubary, Farzad.; Reece, Robert; Marais, Adele; Lombard, Carl

2004-01-01

Objective: The aim of this article is twofold: first, to examine the prevalence of being the victim of actual and attempted rape among a large representative sample of Cape Town high school students; and second, to identify the correlates of sexual assault for both boys and girls, including alcohol, tobacco and other drug use, behavioral problems,…

The Disease Burden of Childhood Adversities in Adults: A Population-Based Study

ERIC Educational Resources Information Center

Cuijpers, Pim; Smit, Filip; Unger, Froukje; Stikkelbroek, Yvonne; ten Have, Margreet; de Graaf, Ron

2011-01-01

Objectives: There is much evidence showing that childhood adversities have considerable effects on the mental and physical health of adults. It could be assumed therefore, that the disease burden of childhood adversities is high. It has not yet been examined, however, whether this is true. Method: We used data of a large representative sample (N =…

Association of Contextual Factors with Drug Use and Binge Drinking among White, Native American, and Mixed-Race Adolescents in the General Population

ERIC Educational Resources Information Center

Chen, Hsing-Jung; Balan, Sundari; Price, Rumi Kato

2012-01-01

Large-scale surveys have shown elevated risk for many indicators of substance abuse among Native American and Mixed-Race adolescents compared to other minority groups in the United States. This study examined underlying contextual factors associated with substance abuse among a nationally representative sample of White, Native American, and…

The Teaching of Literature in a Singapore Secondary School: Disciplinarity, Curriculum Coverage and the Opportunity Costs Involved

ERIC Educational Resources Information Center

Towndrow, Phillip; Kwek, Dennis Beng Kiat

2017-01-01

Set against the backdrop of reinvigorating the study of literature and concerns about the adequate preparation of students for the world of work, this paper explores how a Singapore teacher presented a literary text in the classroom. Drawing on data from a large-scale representative sample of Singapore schools in instruction and assessment…

Teenage Career Aspirations and Adult Career Attainment: The Role of Gender, Social Background and General Cognitive Ability

ERIC Educational Resources Information Center

Schoon, Ingrid; Polek, Elzbieta

2011-01-01

In this paper we examine the associations between gender, family background, general cognitive ability (g), teenage career aspirations, and career attainment in mid adulthood drawing on two large representative samples of the British population born in 1958 (N = 6,474) and in 1970 (N = 5,081). A developmental-contextual model of career development…

Psychosocial Factors in Adolescent and Young Adult Self-Reported Depressive Symptoms: Causal or Correlational Associations?

ERIC Educational Resources Information Center

Steinhausen, Hans-Christoph; Haslimeier, Claudia; Metzke, Christa Winkler

2007-01-01

Using a large longitudinal representative community sample, this study identified three groups of subjects who were depressed either in pre-adolescence, late adolescence or early adulthood, and matched by age and gender to controls without depression. The 90th percentile on one or two self-reported symptom scales [i. e. the Center for…

Distinct Trajectories of Separation Anxiety in the Preschool Years: Persistence at School Entry and Early-Life Associated Factors

ERIC Educational Resources Information Center

Battaglia, Marco; Touchette, Évelyne; Garon-Carrier, Gabrielle; Dionne, Ginette; Côté, Sylvana M.; Vitaro, Frank; Tremblay, Richard E.; Boivin, Michel

2016-01-01

Background: Little is known about how children differ in the onset and evolution of separation anxiety (SA) symptoms during the preschool years, and how SA develops into separation anxiety disorder. In a large, representative population-based sample, we investigated the developmental trajectories of SA symptoms from infancy to school entry, their…

Defining and Assessing Parent Empowerment and Its Relationship to Academic Achievement Using the National Household Education Survey: A Focus on Marginalized Parents

ERIC Educational Resources Information Center

Kim, Jungnam

2012-01-01

Marginalized parents experience multiple and complex challenges in terms of social isolation, exclusion, and powerlessness. This empirical study investigated the effects of parent empowerment on academic outcomes using a large national representative sample and should provide insights about the importance of parent empowerment in education and…

Part-Time Work among High School Seniors: How Much Is Too Much?

ERIC Educational Resources Information Center

Bachman, Jerald G.; Schulenberg, John

This document reports findings from data collected from large nationally representative samples of high school seniors in the classes of 1985-1989 as part of the Monitoring the Future project. Its primary focus is on the possible costs and benefits of part-time work among high school seniors. The focus of the report is on three psychosocial…

Maternal Predictors of Noncoital Sexual Behavior: Examining a Nationally Representative Sample of Asian and White American Adolescents Who Have Never Had Sex

ERIC Educational Resources Information Center

Lam, Amy G.; Russell, Stephen T.; Tan, Thida C.; Leong, Sareen J.

2008-01-01

Current research in adolescent sexuality has largely focused on vaginal-penile intercourse, with less attention to noncoital sexual activity. This study examined how maternal factors influence the transition from virginity to noncoital behavior among White and Asian American youth who have never experienced vaginal intercourse. We conducted…

A large-scale national study of gambling severity among immigrant and non-immigrant adolescents: The role of the family.

PubMed

Canale, Natale; Vieno, Alessio; Griffiths, Mark D; Borraccino, Alberto; Lazzeri, Giacomo; Charrier, Lorena; Lemma, Patrizia; Dalmasso, Paola; Santinello, Massimo

2017-03-01

The primary aim of the present study was to examine the association between immigrant generation, family sociodemographic characteristics, and problem gambling severity in a large-scale nationally representative sample of Italian youth. Data from the 2013-2014 Health Behaviour in School-aged Children (HBSC) Survey were used for cross-sectional analyses of adolescent problem gambling. Self-administered questionnaires were completed by a representative sample of 20,791 15-year-old students. Respondents' problem gambling severity, immigrant status, family characteristics (family structure, family affluence, perceived family support) and socio-demographic characteristics were individually assessed. Rates of adolescent at-risk/problem gambling were twice as high among first generation immigrants than non-immigrant students; the odds of being at-risk/problem gamblers were higher among first-generation immigrants than adolescents of other immigrant generations or non-immigrant. Not living with two biological or adoptive parents appears to be a factor that increases the risk of becoming a problem gambler in first generation immigrants. Immigrant status and family characteristics may play a key role in contributing to adolescent problem gambling. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Lipidomic analysis of biological samples: Comparison of liquid chromatography, supercritical fluid chromatography and direct infusion mass spectrometry methods.

PubMed

Lísa, Miroslav; Cífková, Eva; Khalikova, Maria; Ovčačíková, Magdaléna; Holčapek, Michal

2017-11-24

Lipidomic analysis of biological samples in a clinical research represents challenging task for analytical methods given by the large number of samples and their extreme complexity. In this work, we compare direct infusion (DI) and chromatography - mass spectrometry (MS) lipidomic approaches represented by three analytical methods in terms of comprehensiveness, sample throughput, and validation results for the lipidomic analysis of biological samples represented by tumor tissue, surrounding normal tissue, plasma, and erythrocytes of kidney cancer patients. Methods are compared in one laboratory using the identical analytical protocol to ensure comparable conditions. Ultrahigh-performance liquid chromatography/MS (UHPLC/MS) method in hydrophilic interaction liquid chromatography mode and DI-MS method are used for this comparison as the most widely used methods for the lipidomic analysis together with ultrahigh-performance supercritical fluid chromatography/MS (UHPSFC/MS) method showing promising results in metabolomics analyses. The nontargeted analysis of pooled samples is performed using all tested methods and 610 lipid species within 23 lipid classes are identified. DI method provides the most comprehensive results due to identification of some polar lipid classes, which are not identified by UHPLC and UHPSFC methods. On the other hand, UHPSFC method provides an excellent sensitivity for less polar lipid classes and the highest sample throughput within 10min method time. The sample consumption of DI method is 125 times higher than for other methods, while only 40μL of organic solvent is used for one sample analysis compared to 3.5mL and 4.9mL in case of UHPLC and UHPSFC methods, respectively. Methods are validated for the quantitative lipidomic analysis of plasma samples with one internal standard for each lipid class. Results show applicability of all tested methods for the lipidomic analysis of biological samples depending on the analysis requirements. Copyright © 2017 Elsevier B.V. All rights reserved.

Group extraction of organic compounds present in liquid samples

NASA Technical Reports Server (NTRS)

Jahnsen, Vilhelm J. (Inventor)

1976-01-01

An extraction device is disclosed comprising a tube containing a substantially inert, chemically non-reactive packing material with a large surface area to volume ratio. A sample which consists of organic compounds dissolved in a liquid, is introduced into the tube. As the sample passes through the packing material it spreads over the material's large surface area to form a thin liquid film which is held on the packing material in a stationary state. A particular group or family of compounds is extractable from the sample by passing a particular solvent system consisting of a solvent and selected reagents through the packing material. The reagents cause optimum conditions to exist for the compounds of the particular family to pass through the phase boundary between the sample liquid and the solvent of the solvent system. Thus, the compounds of the particular family are separated from the sample liquid and become dissolved in the solvent of the solvent system. The particular family of compounds dissolved in the solvent, representing an extract, exits the tube together with the solvent through the tube's nozzle, while the rest of the sample remains on the packing material in a stationary state. Subsequently, a different solvent system may be passed through the packing material to extract another family of compounds from the remaining sample on the packing material.

An Improved Nested Sampling Algorithm for Model Selection and Assessment

NASA Astrophysics Data System (ADS)

Zeng, X.; Ye, M.; Wu, J.; WANG, D.

2017-12-01

Multimodel strategy is a general approach for treating model structure uncertainty in recent researches. The unknown groundwater system is represented by several plausible conceptual models. Each alternative conceptual model is attached with a weight which represents the possibility of this model. In Bayesian framework, the posterior model weight is computed as the product of model prior weight and marginal likelihood (or termed as model evidence). As a result, estimating marginal likelihoods is crucial for reliable model selection and assessment in multimodel analysis. Nested sampling estimator (NSE) is a new proposed algorithm for marginal likelihood estimation. The implementation of NSE comprises searching the parameters' space from low likelihood area to high likelihood area gradually, and this evolution is finished iteratively via local sampling procedure. Thus, the efficiency of NSE is dominated by the strength of local sampling procedure. Currently, Metropolis-Hasting (M-H) algorithm and its variants are often used for local sampling in NSE. However, M-H is not an efficient sampling algorithm for high-dimensional or complex likelihood function. For improving the performance of NSE, it could be feasible to integrate more efficient and elaborated sampling algorithm - DREAMzs into the local sampling. In addition, in order to overcome the computation burden problem of large quantity of repeating model executions in marginal likelihood estimation, an adaptive sparse grid stochastic collocation method is used to build the surrogates for original groundwater model.

Sampling studies to estimate the HIV prevalence rate in female commercial sex workers.

PubMed

Pascom, Ana Roberta Pati; Szwarcwald, Célia Landmann; Barbosa Júnior, Aristides

2010-01-01

We investigated sampling methods being used to estimate the HIV prevalence rate among female commercial sex workers. The studies were classified according to the adequacy or not of the sample size to estimate HIV prevalence rate and according to the sampling method (probabilistic or convenience). We identified 75 studies that estimated the HIV prevalence rate among female sex workers. Most of the studies employed convenience samples. The sample size was not adequate to estimate HIV prevalence rate in 35 studies. The use of convenience sample limits statistical inference for the whole group. It was observed that there was an increase in the number of published studies since 2005, as well as in the number of studies that used probabilistic samples. This represents a large advance in the monitoring of risk behavior practices and HIV prevalence rate in this group.

Identification of Species and Sources of Cryptosporidium Oocysts in Storm Waters with a Small-Subunit rRNA-Based Diagnostic and Genotyping Tool

PubMed Central

Xiao, Lihua; Alderisio, Kerri; Limor, Josef; Royer, Michael; Lal, Altaf A.

2000-01-01

The identification of Cryptosporidium oocysts in environmental samples is largely made by the use of an immunofluorescent assay. In this study, we have used a small-subunit rRNA-based PCR-restriction fragment length polymorphism technique to identify species and sources of Cryptosporidium oocysts present in 29 storm water samples collected from a stream in New York. A total of 12 genotypes were found in 27 positive samples; for 4 the species and probable origins were identified by sequence analysis, whereas the rest represent new genotypes from wildlife. Thus, this technique provides an alternative method for the detection and differentiation of Cryptosporidium parasites in environmental samples. PMID:11097935

DOE Office of Scientific and Technical Information (OSTI.GOV)

Puls, R.W.; Powell, R.M.

R.S. Kerr Environmental Research Laboratory (RSKERL) personnel have evaluated sampling procedures for the collection of representative, accurate, and reproducible ground water quality samples for metals for the past four years. Intensive sampling research at three different field sites has shown that the method by which samples are collected has a greater impact on sample quality, accuracy, and reproducibility than whether the samples are filtered or not. In particular, sample collection practices that induce artifically high levels of turbidity have been shown to have the greatest negative impacts on sample quality. Results indicated the ineffectiveness of bailer for collection of representativemore » metal samples. Inconsistent operator usage together with excessive purging generally resulted in excessive turbidity and large differences in filtered and unfiltered metal samples. The use of low flow rate purging and sampling consistently produced filtered and unfiltered samples that showed no significant differences in concentrations. Turbidity levels were generally less than 5 NTUs, even in fine-textured glacial till. The authors recommend the use of low flow rates, during both purging and sampling.« less

Attitudes and Relationship between Physicians and the Pharmaceutical Industry in a Public General Hospital in Lima, Peru

PubMed Central

De Ferrari, Aldo; Gentille, Cesar; Davalos, Long; Huayanay, Leandro; Malaga, German

2014-01-01

Background The interaction between physicians and the pharmaceutical industry influences physicians' attitudes and prescribing behavior. Although largely studied in the US, this topic has not been well studied in resource-poor settings, where a close relationship between physicians and industry still exists. Objective To describe physician interactions with and attitudes towards the pharmaceutical industry in a public general hospital in Lima, Peru. Design Descriptive, cross-sectional study through an anonymous, self-filled questionnaire distributed among faculty and trainee physicians of five different clinical departments working in a Peruvian public general hospital. A transcultural validation of an existing Spanish questionnaire was performed. Exposure to marketing activities, motivations to contact pharmaceutical representatives and attitudes towards industry were studied. Collected data was analyzed by degree of training, clinical department, gender and teaching status. Attitudes were measured on a four-point LIKERT scale. Results 155 physicians completed the survey, of which 148 were included in the study sample. 94.5% of attending physicians reported ongoing encounters with pharmaceutical representatives. The most common industry-related activities were receiving medical samples (91.2%), promotional material (87.8%) and attending meetings in restaurants (81.8%). Respondents considered medical samples and continuing medical education the most ethically acceptable benefits. We found significant differences between attendings and residents, and teaching and non-teaching attendings. An association between the amount of encounters with pharmaceutical representatives, and attitudes towards industry and acceptance of medical samples was found. Conclusions A close physician-industry relationship exists in the population under study. The contact is established mainly through pharmaceutical representatives. Medical samples are the most received and ethically accepted benefit. The attitudes of physicians on the ethical standards of acceptance of medical samples and other benefits are closely related with their exposure to the pharmaceutical industry. Future studies could explore the motivations of physicians working in resource-poor settings to maintain a close relationship with industry. PMID:24978481

Attitudes and relationship between physicians and the pharmaceutical industry in a public general hospital in Lima, Peru.

PubMed

De Ferrari, Aldo; Gentille, Cesar; Davalos, Long; Huayanay, Leandro; Malaga, German

2014-01-01

The interaction between physicians and the pharmaceutical industry influences physicians' attitudes and prescribing behavior. Although largely studied in the US, this topic has not been well studied in resource-poor settings, where a close relationship between physicians and industry still exists. To describe physician interactions with and attitudes towards the pharmaceutical industry in a public general hospital in Lima, Peru. Descriptive, cross-sectional study through an anonymous, self-filled questionnaire distributed among faculty and trainee physicians of five different clinical departments working in a Peruvian public general hospital. A transcultural validation of an existing Spanish questionnaire was performed. Exposure to marketing activities, motivations to contact pharmaceutical representatives and attitudes towards industry were studied. Collected data was analyzed by degree of training, clinical department, gender and teaching status. Attitudes were measured on a four-point LIKERT scale. 155 physicians completed the survey, of which 148 were included in the study sample. 94.5% of attending physicians reported ongoing encounters with pharmaceutical representatives. The most common industry-related activities were receiving medical samples (91.2%), promotional material (87.8%) and attending meetings in restaurants (81.8%). Respondents considered medical samples and continuing medical education the most ethically acceptable benefits. We found significant differences between attendings and residents, and teaching and non-teaching attendings. An association between the amount of encounters with pharmaceutical representatives, and attitudes towards industry and acceptance of medical samples was found. A close physician-industry relationship exists in the population under study. The contact is established mainly through pharmaceutical representatives. Medical samples are the most received and ethically accepted benefit. The attitudes of physicians on the ethical standards of acceptance of medical samples and other benefits are closely related with their exposure to the pharmaceutical industry. Future studies could explore the motivations of physicians working in resource-poor settings to maintain a close relationship with industry.

Biases in the OSSOS Detection of Large Semimajor Axis Trans-Neptunian Objects

NASA Astrophysics Data System (ADS)

Gladman, Brett; Shankman, Cory; OSSOS Collaboration

2017-10-01

The accumulating but small set of large semimajor axis trans-Neptunian objects (TNOs) shows an apparent clustering in the orientations of their orbits. This clustering must either be representative of the intrinsic distribution of these TNOs, or else have arisen as a result of observation biases and/or statistically expected variations for such a small set of detected objects. The clustered TNOs were detected across different and independent surveys, which has led to claims that the detections are therefore free of observational bias. This apparent clustering has led to the so-called “Planet 9” hypothesis that a super-Earth currently resides in the distant solar system and causes this clustering. The Outer Solar System Origins Survey (OSSOS) is a large program that ran on the Canada-France-Hawaii Telescope from 2013 to 2017, discovering more than 800 new TNOs. One of the primary design goals of OSSOS was the careful determination of observational biases that would manifest within the detected sample. We demonstrate the striking and non-intuitive biases that exist for the detection of TNOs with large semimajor axes. The eight large semimajor axis OSSOS detections are an independent data set, of comparable size to the conglomerate samples used in previous studies. We conclude that the orbital distribution of the OSSOS sample is consistent with being detected from a uniform underlying angular distribution.

OSSOS. VI. Striking Biases in the Detection of Large Semimajor Axis Trans-Neptunian Objects

NASA Astrophysics Data System (ADS)

Shankman, Cory; Kavelaars, J. J.; Bannister, Michele T.; Gladman, Brett J.; Lawler, Samantha M.; Chen, Ying-Tung; Jakubik, Marian; Kaib, Nathan; Alexandersen, Mike; Gwyn, Stephen D. J.; Petit, Jean-Marc; Volk, Kathryn

2017-08-01

The accumulating but small set of large semimajor axis trans-Neptunian objects (TNOs) shows an apparent clustering in the orientations of their orbits. This clustering must either be representative of the intrinsic distribution of these TNOs, or else have arisen as a result of observation biases and/or statistically expected variations for such a small set of detected objects. The clustered TNOs were detected across different and independent surveys, which has led to claims that the detections are therefore free of observational bias. This apparent clustering has led to the so-called “Planet 9” hypothesis that a super-Earth currently resides in the distant solar system and causes this clustering. The Outer Solar System Origins Survey (OSSOS) is a large program that ran on the Canada–France–Hawaii Telescope from 2013 to 2017, discovering more than 800 new TNOs. One of the primary design goals of OSSOS was the careful determination of observational biases that would manifest within the detected sample. We demonstrate the striking and non-intuitive biases that exist for the detection of TNOs with large semimajor axes. The eight large semimajor axis OSSOS detections are an independent data set, of comparable size to the conglomerate samples used in previous studies. We conclude that the orbital distribution of the OSSOS sample is consistent with being detected from a uniform underlying angular distribution.

Screen-Space Normal Distribution Function Caching for Consistent Multi-Resolution Rendering of Large Particle Data.

PubMed

Ibrahim, Mohamed; Wickenhauser, Patrick; Rautek, Peter; Reina, Guido; Hadwiger, Markus

2018-01-01

Molecular dynamics (MD) simulations are crucial to investigating important processes in physics and thermodynamics. The simulated atoms are usually visualized as hard spheres with Phong shading, where individual particles and their local density can be perceived well in close-up views. However, for large-scale simulations with 10 million particles or more, the visualization of large fields-of-view usually suffers from strong aliasing artifacts, because the mismatch between data size and output resolution leads to severe under-sampling of the geometry. Excessive super-sampling can alleviate this problem, but is prohibitively expensive. This paper presents a novel visualization method for large-scale particle data that addresses aliasing while enabling interactive high-quality rendering. We introduce the novel concept of screen-space normal distribution functions (S-NDFs) for particle data. S-NDFs represent the distribution of surface normals that map to a given pixel in screen space, which enables high-quality re-lighting without re-rendering particles. In order to facilitate interactive zooming, we cache S-NDFs in a screen-space mipmap (S-MIP). Together, these two concepts enable interactive, scale-consistent re-lighting and shading changes, as well as zooming, without having to re-sample the particle data. We show how our method facilitates the interactive exploration of real-world large-scale MD simulation data in different scenarios.

Large fluxes and rapid turnover of mineral-associated carbon across topographic gradients in a humid tropical forest: insights from paired 14C analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hall, S. J.; McNicol, G.; Natake, T.

2015-04-29

It has been proposed that the large soil carbon (C) stocks of humid tropical forests result predominantly from C stabilization by reactive minerals, whereas oxygen (O 2) limitation of decomposition has received much less attention. We examined the importance of these factors in explaining patterns of C stocks and turnover in the Luquillo Experimental Forest, Puerto Rico, using radiocarbon ( 14C) measurements of contemporary and archived samples. Samples from ridge, slope, and valley positions spanned three soil orders (Ultisol, Oxisol, Inceptisol) representative of humid tropical forests, and differed in texture, reactive metal content, O 2 availability, and root biomass. Mineral-associatedmore » C comprised the large majority (87 ± 2%, n = 30) of total soil C. Turnover of most mineral-associated C (66 ± 2%) was rapid (11 to 26 years; mean and SE: 18 ± 3 years) in 25 of 30 soil samples across surface horizons (0–10 and 10–20 cm depths) and all topographic positions, independent of variation in reactive metal concentrations and clay content. Passive C with centennial–millennial turnover was typically much less abundant (34 ± 3%), even at 10–20 cm depths. Carbon turnover times and concentrations significantly increased with concentrations of reduced iron (Fe(II)) across all samples, suggesting that O 2 availability may have limited the decomposition of mineral-associated C over decadal scales. Steady-state inputs of mineral-associated C were statistically similar among the three topographic positions, and could represent 10–25% of annual litter production. Observed trends in mineral-associated Δ 14C over time could not be fit using the single-pool model used in many other studies, which generated contradictory relationships between turnover and Δ 14C as compared with a more realistic two-pool model. The large C fluxes in surface and near-surface soils documented here are supported by findings from paired 14C studies in other types of ecosystems, and suggest that most mineral-associated C cycles relatively rapidly (decadal scales) across ecosystems that span a broad range of state factors.« less

Survey research with a random digit dial national mobile phone sample in Ghana: Methods and sample quality.

PubMed

L'Engle, Kelly; Sefa, Eunice; Adimazoya, Edward Akolgo; Yartey, Emmanuel; Lenzi, Rachel; Tarpo, Cindy; Heward-Mills, Nii Lante; Lew, Katherine; Ampeh, Yvonne

2018-01-01

Generating a nationally representative sample in low and middle income countries typically requires resource-intensive household level sampling with door-to-door data collection. High mobile phone penetration rates in developing countries provide new opportunities for alternative sampling and data collection methods, but there is limited information about response rates and sample biases in coverage and nonresponse using these methods. We utilized data from an interactive voice response, random-digit dial, national mobile phone survey in Ghana to calculate standardized response rates and assess representativeness of the obtained sample. The survey methodology was piloted in two rounds of data collection. The final survey included 18 demographic, media exposure, and health behavior questions. Call outcomes and response rates were calculated according to the American Association of Public Opinion Research guidelines. Sample characteristics, productivity, and costs per interview were calculated. Representativeness was assessed by comparing data to the Ghana Demographic and Health Survey and the National Population and Housing Census. The survey was fielded during a 27-day period in February-March 2017. There were 9,469 completed interviews and 3,547 partial interviews. Response, cooperation, refusal, and contact rates were 31%, 81%, 7%, and 39% respectively. Twenty-three calls were dialed to produce an eligible contact: nonresponse was substantial due to the automated calling system and dialing of many unassigned or non-working numbers. Younger, urban, better educated, and male respondents were overrepresented in the sample. The innovative mobile phone data collection methodology yielded a large sample in a relatively short period. Response rates were comparable to other surveys, although substantial coverage bias resulted from fewer women, rural, and older residents completing the mobile phone survey in comparison to household surveys. Random digit dialing of mobile phones offers promise for future data collection in Ghana and may be suitable for other developing countries.

Survey research with a random digit dial national mobile phone sample in Ghana: Methods and sample quality

PubMed Central

Sefa, Eunice; Adimazoya, Edward Akolgo; Yartey, Emmanuel; Lenzi, Rachel; Tarpo, Cindy; Heward-Mills, Nii Lante; Lew, Katherine; Ampeh, Yvonne

2018-01-01

Introduction Generating a nationally representative sample in low and middle income countries typically requires resource-intensive household level sampling with door-to-door data collection. High mobile phone penetration rates in developing countries provide new opportunities for alternative sampling and data collection methods, but there is limited information about response rates and sample biases in coverage and nonresponse using these methods. We utilized data from an interactive voice response, random-digit dial, national mobile phone survey in Ghana to calculate standardized response rates and assess representativeness of the obtained sample. Materials and methods The survey methodology was piloted in two rounds of data collection. The final survey included 18 demographic, media exposure, and health behavior questions. Call outcomes and response rates were calculated according to the American Association of Public Opinion Research guidelines. Sample characteristics, productivity, and costs per interview were calculated. Representativeness was assessed by comparing data to the Ghana Demographic and Health Survey and the National Population and Housing Census. Results The survey was fielded during a 27-day period in February-March 2017. There were 9,469 completed interviews and 3,547 partial interviews. Response, cooperation, refusal, and contact rates were 31%, 81%, 7%, and 39% respectively. Twenty-three calls were dialed to produce an eligible contact: nonresponse was substantial due to the automated calling system and dialing of many unassigned or non-working numbers. Younger, urban, better educated, and male respondents were overrepresented in the sample. Conclusions The innovative mobile phone data collection methodology yielded a large sample in a relatively short period. Response rates were comparable to other surveys, although substantial coverage bias resulted from fewer women, rural, and older residents completing the mobile phone survey in comparison to household surveys. Random digit dialing of mobile phones offers promise for future data collection in Ghana and may be suitable for other developing countries. PMID:29351349

Spatial Representativeness of Environmental DNA Metabarcoding Signal for Fish Biodiversity Assessment in a Natural Freshwater System.

PubMed

Civade, Raphaël; Dejean, Tony; Valentini, Alice; Roset, Nicolas; Raymond, Jean-Claude; Bonin, Aurélie; Taberlet, Pierre; Pont, Didier

2016-01-01

In the last few years, the study of environmental DNA (eDNA) has drawn attention for many reasons, including its advantages for monitoring and conservation purposes. So far, in aquatic environments, most of eDNA research has focused on the detection of single species using species-specific markers. Recently, species inventories based on the analysis of a single generalist marker targeting a larger taxonomic group (eDNA metabarcoding) have proven useful for bony fish and amphibian biodiversity surveys. This approach involves in situ filtering of large volumes of water followed by amplification and sequencing of a short discriminative fragment from the 12S rDNA mitochondrial gene. In this study, we went one step further by investigating the spatial representativeness (i.e. ecological reliability and signal variability in space) of eDNA metabarcoding for large-scale fish biodiversity assessment in a freshwater system including lentic and lotic environments. We tested the ability of this approach to characterize large-scale organization of fish communities along a longitudinal gradient, from a lake to the outflowing river. First, our results confirm that eDNA metabarcoding is more efficient than a single traditional sampling campaign to detect species presence, especially in rivers. Second, the species list obtained using this approach is comparable to the one obtained when cumulating all traditional sampling sessions since 1995 and 1988 for the lake and the river, respectively. In conclusion, eDNA metabarcoding gives a faithful description of local fish biodiversity in the study system, more specifically within a range of a few kilometers along the river in our study conditions, i.e. longer than a traditional fish sampling site.

Spatial and Temporal Dynamics of Pacific Oyster Hemolymph Microbiota across Multiple Scales

PubMed Central

Lokmer, Ana; Goedknegt, M. Anouk; Thieltges, David W.; Fiorentino, Dario; Kuenzel, Sven; Baines, John F.; Wegner, K. Mathias

2016-01-01

Unveiling the factors and processes that shape the dynamics of host associated microbial communities (microbiota) under natural conditions is an important part of understanding and predicting an organism's response to a changing environment. The microbiota is shaped by host (i.e., genetic) factors as well as by the biotic and abiotic environment. Studying natural variation of microbial community composition in multiple host genetic backgrounds across spatial as well as temporal scales represents a means to untangle this complex interplay. Here, we combined a spatially-stratified with a longitudinal sampling scheme within differentiated host genetic backgrounds by reciprocally transplanting Pacific oysters between two sites in the Wadden Sea (Sylt and Texel). To further differentiate contingent site from host genetic effects, we repeatedly sampled the same individuals over a summer season to examine structure, diversity and dynamics of individual hemolymph microbiota following experimental removal of resident microbiota by antibiotic treatment. While a large proportion of microbiome variation could be attributed to immediate environmental conditions, we observed persistent effects of antibiotic treatment and translocation suggesting that hemolymph microbial community dynamics is subject to within-microbiome interactions and host population specific factors. In addition, the analysis of spatial variation revealed that the within-site microenvironmental heterogeneity resulted in high small-scale variability, as opposed to large-scale (between-site) stability. Similarly, considerable within-individual temporal variability was in contrast with the overall temporal stability at the site level. Overall, our longitudinal, spatially-stratified sampling design revealed that variation in hemolymph microbiota is strongly influenced by site and immediate environmental conditions, whereas internal microbiome dynamics and oyster-related factors add to their long-term stability. The combination of small and large scale resolution of spatial and temporal observations therefore represents a crucial but underused tool to study host-associated microbiome dynamics. PMID:27630625

The prevalence of compulsive buying: a meta-analysis.

PubMed

Maraz, Aniko; Griffiths, Mark D; Demetrovics, Zsolt

2016-03-01

To estimate the pooled prevalence of compulsive buying behaviour (CBB) in different populations and to determine the effect of age, gender, location and screening instrument on the reported heterogeneity in estimates of CBB and whether publication bias could be identified. Three databases were searched (Medline, PsychInfo, Web of Science) using the terms 'compulsive buying', 'pathological buying' and 'compulsive shopping' to estimate the pooled prevalence of CBB in different populations. Forty studies reporting 49 prevalence estimates from 16 countries were located (n = 32,000). To conduct the meta-analysis, data from non-clinical studies regarding mean age and gender proportion, geographical study location and screening instrument used to assess CBB were extracted by multiple independent observers and evaluated using a random-effects model. Four a priori subgroups were analysed using pooled estimation (Cohen's Q) and covariate testing (moderator and meta-regression analysis). The CBB pooled prevalence of adult representative studies was 4.9% (3.4-6.9%, eight estimates, 10,102 participants), although estimates were higher among university students: 8.3% (5.9-11.5%, 19 estimates, 14,947 participants) in adult non-representative samples: 12.3% (7.6-19.1%, 11 estimates, 3929 participants) and in shopping-specific samples: 16.2% (8.8-27.8%, 11 estimates, 4686 participants). Being young and female were associated with increased tendency, but not location (United States versus non-United States). Meta-regression revealed large heterogeneity within subgroups, due mainly to diverse measures and time-frames (current versus life-time) used to assess CBB. A pooled estimate of compulsive buying behaviour in the populations studied is approximately 5%, but there is large variation between samples accounted for largely by use of different time-frames and measures. © 2016 Society for the Study of Addiction.

Vitamin D receptor gene and osteoporosis - author`s response

DOE Office of Scientific and Technical Information (OSTI.GOV)

Looney, J.E.; Yoon, Hyun Koo; Fischer, M.

1996-04-01

We appreciate the comments of Dr. Nguyen et al. about our recent study, but we disagree with their suggestion that the lack of an association between low bone density and the BB VDR genotype, which we reported, is an artifact generated by the small sample size. Furthermore, our results are consistent with similar conclusions reached by a number of other investigators, as recently reported by Peacock. Peacock states {open_quotes}Taken as a whole, the results of studies outlined ... indicate that VDR alleles, cannot account for the major part of the heritable component of bone density as indicated by Morrison etmore » al.{close_quotes}. The majority of the 17 studies cited in this editorial could not confirm an association between the VDR genotype and the bone phenotype. Surely one cannot criticize this combined work as representing an artifact because of a too small sample size. We do not dispute the suggestion by Nguyen et al. that large sample sizes are required to analyze small biological effects. This is evident in both Peacock`s summary and in their own bone density studies. We did not design our study with a larger sample size because, based on the work of Morrison et al., we had hypothesized a large biological effect; large sample sizes are only needed for small biological effects. 4 refs.« less

AST: an automated sequence-sampling method for improving the taxonomic diversity of gene phylogenetic trees.

PubMed

Zhou, Chan; Mao, Fenglou; Yin, Yanbin; Huang, Jinling; Gogarten, Johann Peter; Xu, Ying

2014-01-01

A challenge in phylogenetic inference of gene trees is how to properly sample a large pool of homologous sequences to derive a good representative subset of sequences. Such a need arises in various applications, e.g. when (1) accuracy-oriented phylogenetic reconstruction methods may not be able to deal with a large pool of sequences due to their high demand in computing resources; (2) applications analyzing a collection of gene trees may prefer to use trees with fewer operational taxonomic units (OTUs), for instance for the detection of horizontal gene transfer events by identifying phylogenetic conflicts; and (3) the pool of available sequences is biased towards extensively studied species. In the past, the creation of subsamples often relied on manual selection. Here we present an Automated sequence-Sampling method for improving the Taxonomic diversity of gene phylogenetic trees, AST, to obtain representative sequences that maximize the taxonomic diversity of the sampled sequences. To demonstrate the effectiveness of AST, we have tested it to solve four problems, namely, inference of the evolutionary histories of the small ribosomal subunit protein S5 of E. coli, 16 S ribosomal RNAs and glycosyl-transferase gene family 8, and a study of ancient horizontal gene transfers from bacteria to plants. Our results show that the resolution of our computational results is almost as good as that of manual inference by domain experts, hence making the tool generally useful to phylogenetic studies by non-phylogeny specialists. The program is available at http://csbl.bmb.uga.edu/~zhouchan/AST.php.

AST: An Automated Sequence-Sampling Method for Improving the Taxonomic Diversity of Gene Phylogenetic Trees

PubMed Central

Zhou, Chan; Mao, Fenglou; Yin, Yanbin; Huang, Jinling; Gogarten, Johann Peter; Xu, Ying

2014-01-01

A challenge in phylogenetic inference of gene trees is how to properly sample a large pool of homologous sequences to derive a good representative subset of sequences. Such a need arises in various applications, e.g. when (1) accuracy-oriented phylogenetic reconstruction methods may not be able to deal with a large pool of sequences due to their high demand in computing resources; (2) applications analyzing a collection of gene trees may prefer to use trees with fewer operational taxonomic units (OTUs), for instance for the detection of horizontal gene transfer events by identifying phylogenetic conflicts; and (3) the pool of available sequences is biased towards extensively studied species. In the past, the creation of subsamples often relied on manual selection. Here we present an Automated sequence-Sampling method for improving the Taxonomic diversity of gene phylogenetic trees, AST, to obtain representative sequences that maximize the taxonomic diversity of the sampled sequences. To demonstrate the effectiveness of AST, we have tested it to solve four problems, namely, inference of the evolutionary histories of the small ribosomal subunit protein S5 of E. coli, 16 S ribosomal RNAs and glycosyl-transferase gene family 8, and a study of ancient horizontal gene transfers from bacteria to plants. Our results show that the resolution of our computational results is almost as good as that of manual inference by domain experts, hence making the tool generally useful to phylogenetic studies by non-phylogeny specialists. The program is available at http://csbl.bmb.uga.edu/~zhouchan/AST.php. PMID:24892935

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pavlou, A. T.; Betzler, B. R.; Burke, T. P.

Uncertainties in the composition and fabrication of fuel compacts for the Fort St. Vrain (FSV) high temperature gas reactor have been studied by performing eigenvalue sensitivity studies that represent the key uncertainties for the FSV neutronic analysis. The uncertainties for the TRISO fuel kernels were addressed by developing a suite of models for an 'average' FSV fuel compact that models the fuel as (1) a mixture of two different TRISO fuel particles representing fissile and fertile kernels, (2) a mixture of four different TRISO fuel particles representing small and large fissile kernels and small and large fertile kernels and (3)more » a stochastic mixture of the four types of fuel particles where every kernel has its diameter sampled from a continuous probability density function. All of the discrete diameter and continuous diameter fuel models were constrained to have the same fuel loadings and packing fractions. For the non-stochastic discrete diameter cases, the MCNP compact model arranged the TRISO fuel particles on a hexagonal honeycomb lattice. This lattice-based fuel compact was compared to a stochastic compact where the locations (and kernel diameters for the continuous diameter cases) of the fuel particles were randomly sampled. Partial core configurations were modeled by stacking compacts into fuel columns containing graphite. The differences in eigenvalues between the lattice-based and stochastic models were small but the runtime of the lattice-based fuel model was roughly 20 times shorter than with the stochastic-based fuel model. (authors)« less

Multiscale dispersion-state characterization of nanocomposites using optical coherence tomography

PubMed Central

Schneider, Simon; Eppler, Florian; Weber, Marco; Olowojoba, Ganiu; Weiss, Patrick; Hübner, Christof; Mikonsaari, Irma; Freude, Wolfgang; Koos, Christian

2016-01-01

Nanocomposite materials represent a success story of nanotechnology. However, development of nanomaterial fabrication still suffers from the lack of adequate analysis tools. In particular, achieving and maintaining well-dispersed particle distributions is a key challenge, both in material development and industrial production. Conventional methods like optical or electron microscopy need laborious, costly sample preparation and do not permit fast extraction of nanoscale structural information from statistically relevant sample volumes. Here we show that optical coherence tomography (OCT) represents a versatile tool for nanomaterial characterization, both in a laboratory and in a production environment. The technique does not require sample preparation and is applicable to a wide range of solid and liquid material systems. Large particle agglomerates can be directly found by OCT imaging, whereas dispersed nanoparticles are detected by model-based analysis of depth-dependent backscattering. Using a model system of polystyrene nanoparticles, we demonstrate nanoparticle sizing with high accuracy. We further prove the viability of the approach by characterizing highly relevant material systems based on nanoclays or carbon nanotubes. The technique is perfectly suited for in-line metrology in a production environment, which is demonstrated using a state-of-the-art compounding extruder. These experiments represent the first demonstration of multiscale nanomaterial characterization using OCT. PMID:27557544

Multiscale dispersion-state characterization of nanocomposites using optical coherence tomography.

PubMed

Schneider, Simon; Eppler, Florian; Weber, Marco; Olowojoba, Ganiu; Weiss, Patrick; Hübner, Christof; Mikonsaari, Irma; Freude, Wolfgang; Koos, Christian

2016-08-25

Nanocomposite materials represent a success story of nanotechnology. However, development of nanomaterial fabrication still suffers from the lack of adequate analysis tools. In particular, achieving and maintaining well-dispersed particle distributions is a key challenge, both in material development and industrial production. Conventional methods like optical or electron microscopy need laborious, costly sample preparation and do not permit fast extraction of nanoscale structural information from statistically relevant sample volumes. Here we show that optical coherence tomography (OCT) represents a versatile tool for nanomaterial characterization, both in a laboratory and in a production environment. The technique does not require sample preparation and is applicable to a wide range of solid and liquid material systems. Large particle agglomerates can be directly found by OCT imaging, whereas dispersed nanoparticles are detected by model-based analysis of depth-dependent backscattering. Using a model system of polystyrene nanoparticles, we demonstrate nanoparticle sizing with high accuracy. We further prove the viability of the approach by characterizing highly relevant material systems based on nanoclays or carbon nanotubes. The technique is perfectly suited for in-line metrology in a production environment, which is demonstrated using a state-of-the-art compounding extruder. These experiments represent the first demonstration of multiscale nanomaterial characterization using OCT.

Adaptive Importance Sampling for Control and Inference

NASA Astrophysics Data System (ADS)

Kappen, H. J.; Ruiz, H. C.

2016-03-01

Path integral (PI) control problems are a restricted class of non-linear control problems that can be solved formally as a Feynman-Kac PI and can be estimated using Monte Carlo sampling. In this contribution we review PI control theory in the finite horizon case. We subsequently focus on the problem how to compute and represent control solutions. We review the most commonly used methods in robotics and control. Within the PI theory, the question of how to compute becomes the question of importance sampling. Efficient importance samplers are state feedback controllers and the use of these requires an efficient representation. Learning and representing effective state-feedback controllers for non-linear stochastic control problems is a very challenging, and largely unsolved, problem. We show how to learn and represent such controllers using ideas from the cross entropy method. We derive a gradient descent method that allows to learn feed-back controllers using an arbitrary parametrisation. We refer to this method as the path integral cross entropy method or PICE. We illustrate this method for some simple examples. The PI control methods can be used to estimate the posterior distribution in latent state models. In neuroscience these problems arise when estimating connectivity from neural recording data using EM. We demonstrate the PI control method as an accurate alternative to particle filtering.

Representativeness of direct observations selected using a work-sampling equation.

PubMed

Sharp, Rebecca A; Mudford, Oliver C; Elliffe, Douglas

2015-01-01

Deciding on appropriate sampling to obtain representative samples of behavior is important but not straightforward, because the relative duration of the target behavior may affect its observation in a given sampling interval. Work-sampling methods, which offer a way to adjust the frequency of sampling according to a priori or ongoing estimates of the behavior to achieve a preselected level of representativeness, may provide a solution. Full-week observations of 7 behaviors were conducted for 3 students with autism spectrum disorder and intellectual disabilities. Work-sampling methods were used to select momentary time samples from the full time-of-interest, which produced representative samples. However, work sampling required impractically high numbers of time samples to obtain representative samples. More practical momentary time samples produced less representative samples, particularly for low-duration behaviors. The utility and limits of work-sampling methods for applied behavior analysis are discussed. © Society for the Experimental Analysis of Behavior.

High-Throughput Microbore UPLC-MS Metabolic Phenotyping of Urine for Large-Scale Epidemiology Studies.

PubMed

Gray, Nicola; Lewis, Matthew R; Plumb, Robert S; Wilson, Ian D; Nicholson, Jeremy K

2015-06-05

A new generation of metabolic phenotyping centers are being created to meet the increasing demands of personalized healthcare, and this has resulted in a major requirement for economical, high-throughput metabonomic analysis by liquid chromatography-mass spectrometry (LC-MS). Meeting these new demands represents an emerging bioanalytical problem that must be solved if metabolic phenotyping is to be successfully applied to large clinical and epidemiological sample sets. Ultraperformance (UP)LC-MS-based metabolic phenotyping, based on 2.1 mm i.d. LC columns, enables comprehensive metabolic phenotyping but, when employed for the analysis of thousands of samples, results in high solvent usage. The use of UPLC-MS employing 1 mm i.d. columns for metabolic phenotyping rather than the conventional 2.1 mm i.d. methodology shows that the resulting optimized microbore method provided equivalent or superior performance in terms of peak capacity, sensitivity, and robustness. On average, we also observed, when using the microbore scale separation, an increase in response of 2-3 fold over that obtained with the standard 2.1 mm scale method. When applied to the analysis of human urine, the 1 mm scale method showed no decline in performance over the course of 1000 analyses, illustrating that microbore UPLC-MS represents a viable alternative to conventional 2.1 mm i.d. formats for routine large-scale metabolic profiling studies while also resulting in a 75% reduction in solvent usage. The modest increase in sensitivity provided by this methodology also offers the potential to either reduce sample consumption or increase the number of metabolite features detected with confidence due to the increased signal-to-noise ratios obtained. Implementation of this miniaturized UPLC-MS method of metabolic phenotyping results in clear analytical, economic, and environmental benefits for large-scale metabolic profiling studies with similar or improved analytical performance compared to conventional UPLC-MS.

Entomofauna of Ziban Oasis, Biskra, Algeria

PubMed Central

Deghiche-Diab, Nassima; Porcelli, Francisco; Belhamra, Mohamed

2015-01-01

An inventory was carried out at five stations in the oasis of Ziban, an oasis that is characterized by its high-quality dates, in order to study the relationships between the oasis ecosystem and its insect fauna. Specimens were sampled using pitfall traps containing ethylene glycol as a preservative. In total, 115 arthropod species were collected during 5 months of survey. These species belonged to 61 families, 17 orders, and 4 classes (12 orders from Insecta, 3 from Arachnida, 1 from Chilopoda, and 1 from Malocostraca). The most represented insect orders were Coleoptera (44.42%), Hymenoptera (20.86%), and Lepidoptera (7.87%). Represented in the collections were phytophagous, omnivorous, and predator/parasite species. Given the large number of species collected, and the largely unknown relationships existing between the various ecological groups, this study is a first step in the description of the oasis entomofauna. PMID:25855607

Using archetypes to create user panels for usability studies: Streamlining focus groups and user studies.

PubMed

Stavrakos, S-K; Ahmed-Kristensen, S; Goldman, T

2016-09-01

Designers at the conceptual phase of products such as headphones, stress the importance of comfort, e.g. executing comfort studies and the need for a reliable user panel. This paper proposes a methodology to issue a reliable user panel to represent large populations and validates the proposed framework to predict comfort factors, such as physical fit. Data of 200 heads was analyzed by forming clusters, 9 archetypal people were identified out of a 200 people's ear database. The archetypes were validated by comparing the archetypes' responses on physical fit against those of 20 participants interacting with 6 headsets. This paper suggests a new method of selecting representative user samples for prototype testing compared to costly and time consuming methods which relied on the analysis of human geometry of large populations. Copyright © 2016 Elsevier Ltd. All rights reserved.

Geologic Map of the Meskhent Tessera Quadrangle (V-3), Venus: Evidence for Early Formation and Preservation of Regional Topography

NASA Technical Reports Server (NTRS)

Ivanov, M. A.; Head, James W.

2008-01-01

The area of the Meskhent Tessera quadrangle (V-3, 50-75degN, 60-120degE, Fig. 1) corresponds to a transition zone from the uplands of Ishtar Terra to the west to the lowlands of Atalanta Planitia to the east. The topographic configuration, gravity signature, and presence of large tesserae in Ishtar Terra are consistent with extensive areas of thickened crust and tectonically stabilized lithosphere representing ancient and now extinct regimes of mantle convection. The gravity and topographic characteristics of Atalanta Planitia have been cited as evidence for large-scale mantle downwelling. Thus, the region of Meskhent Tessera quadrangle represents an important sample for the study of the regional history of long-wavelength topography (highlands, midlands, and lowlands), interaction between the downwelling and areas of thickened crust/lithosphere, formation of associated tectonic features, and emplacement of volcanic plains.

Intermediate Pond Sizes Contain the Highest Density, Richness, and Diversity of Pond-Breeding Amphibians

PubMed Central

Semlitsch, Raymond D.; Peterman, William E.; Anderson, Thomas L.; Drake, Dana L.; Ousterhout, Brittany H.

2015-01-01

We present data on amphibian density, species richness, and diversity from a 7140-ha area consisting of 200 ponds in the Midwestern U.S. that represents most of the possible lentic aquatic breeding habitats common in this region. Our study includes all possible breeding sites with natural and anthropogenic disturbance processes that can be missing from studies where sampling intensity is low, sample area is small, or partial disturbance gradients are sampled. We tested whether pond area was a significant predictor of density, species richness, and diversity of amphibians and if values peaked at intermediate pond areas. We found that in all cases a quadratic model fit our data significantly better than a linear model. Because small ponds have a high probability of pond drying and large ponds have a high probability of fish colonization and accumulation of invertebrate predators, drying and predation may be two mechanisms driving the peak of density and diversity towards intermediate values of pond size. We also found that not all intermediate sized ponds produced many larvae; in fact, some had low amphibian density, richness, and diversity. Further analyses of the subset of ponds represented in the peak of the area distribution showed that fish, hydroperiod, invertebrate density, and canopy are additional factors that drive density, richness and diversity of ponds up or down, when extremely small or large ponds are eliminated. Our results indicate that fishless ponds at intermediate sizes are more diverse, produce more larvae, and have greater potential to recruit juveniles into adult populations of most species sampled. Further, hylid and chorus frogs are found predictably more often in ephemeral ponds whereas bullfrogs, green frogs, and cricket frogs are found most often in permanent ponds with fish. Our data increase understanding of what factors structure and maintain amphibian diversity across large landscapes. PMID:25906355

Bacterial diversity of surface sand samples from the Gobi and Taklamaken deserts.

PubMed

An, Shu; Couteau, Cécile; Luo, Fan; Neveu, Julie; DuBow, Michael S

2013-11-01

Arid regions represent nearly 30 % of the Earth's terrestrial surface, but their microbial biodiversity is not yet well characterized. The surface sands of deserts, a subset of arid regions, are generally subjected to large temperature fluctuations plus high UV light exposure and are low in organic matter. We examined surface sand samples from the Taklamaken (China, three samples) and Gobi (Mongolia, two samples) deserts, using pyrosequencing of PCR-amplified 16S V1/V2 rDNA sequences from total extracted DNA in order to gain an assessment of the bacterial population diversity. In total, 4,088 OTUs (using ≥97 % sequence similarity levels), with Chao1 estimates varying from 1,172 to 2,425 OTUs per sample, were discernable. These could be grouped into 102 families belonging to 15 phyla, with OTUs belonging to the Firmicutes, Proteobacteria, Bacteroidetes, and Actinobacteria phyla being the most abundant. The bacterial population composition was statistically different among the samples, though members from 30 genera were found to be common among the five samples. An increase in phylotype numbers with increasing C/N ratio was noted, suggesting a possible role in the bacterial richness of these desert sand environments. Our results imply an unexpectedly large bacterial diversity residing in the harsh environment of these two Asian deserts, worthy of further investigation.

Reconstruction of three-dimensional porous media using generative adversarial neural networks

NASA Astrophysics Data System (ADS)

Mosser, Lukas; Dubrule, Olivier; Blunt, Martin J.

2017-10-01

To evaluate the variability of multiphase flow properties of porous media at the pore scale, it is necessary to acquire a number of representative samples of the void-solid structure. While modern x-ray computer tomography has made it possible to extract three-dimensional images of the pore space, assessment of the variability in the inherent material properties is often experimentally not feasible. We present a method to reconstruct the solid-void structure of porous media by applying a generative neural network that allows an implicit description of the probability distribution represented by three-dimensional image data sets. We show, by using an adversarial learning approach for neural networks, that this method of unsupervised learning is able to generate representative samples of porous media that honor their statistics. We successfully compare measures of pore morphology, such as the Euler characteristic, two-point statistics, and directional single-phase permeability of synthetic realizations with the calculated properties of a bead pack, Berea sandstone, and Ketton limestone. Results show that generative adversarial networks can be used to reconstruct high-resolution three-dimensional images of porous media at different scales that are representative of the morphology of the images used to train the neural network. The fully convolutional nature of the trained neural network allows the generation of large samples while maintaining computational efficiency. Compared to classical stochastic methods of image reconstruction, the implicit representation of the learned data distribution can be stored and reused to generate multiple realizations of the pore structure very rapidly.

Intuitive intellectual property law: A nationally-representative test of the plagiarism fallacy.

PubMed

Fast, Anne A; Olson, Kristina R; Mandel, Gregory N

2017-01-01

Studies with convenience samples have suggested that the lay public's conception of intellectual property laws, including how the laws should regulate and why they should exist, are largely incommensurate with the actual intended purpose of intellectual property laws and their history in the United States. In this paper, we test whether these findings generalize to a more diverse and representative sample. The major findings from past work were replicated in the current study. When presented with several potential reasons for IP protection, the lay public endorsed plagiarism and felt that acknowledging the original source of a creative work should make copying that work permissible-viewpoints strongly divergent from lawmakers' intent and the law itself. In addition, we replicate the finding that lay people know remarkably little about intellectual property laws more generally and report little experience as users or creators of creative works.

Intuitive intellectual property law: A nationally-representative test of the plagiarism fallacy

PubMed Central

Olson, Kristina R.; Mandel, Gregory N.

2017-01-01

Studies with convenience samples have suggested that the lay public’s conception of intellectual property laws, including how the laws should regulate and why they should exist, are largely incommensurate with the actual intended purpose of intellectual property laws and their history in the United States. In this paper, we test whether these findings generalize to a more diverse and representative sample. The major findings from past work were replicated in the current study. When presented with several potential reasons for IP protection, the lay public endorsed plagiarism and felt that acknowledging the original source of a creative work should make copying that work permissible—viewpoints strongly divergent from lawmakers’ intent and the law itself. In addition, we replicate the finding that lay people know remarkably little about intellectual property laws more generally and report little experience as users or creators of creative works. PMID:28863170

The enigmatic molar from Gondolin, South Africa: implications for Paranthropus paleobiology.

PubMed

Grine, Frederick E; Jacobs, Rachel L; Reed, Kaye E; Plavcan, J Michael

2012-10-01

The specific attribution of the large hominin M(2) (GDA-2) from Gondolin has significant implications for the paleobiology of Paranthropus. If it is a specimen of Paranthropus robustus it impacts that species' size range, and if it belongs to Paranthropus boisei it has important biogeographic implications. We evaluate crown size, cusp proportions and the likelihood of encountering a large-bodied mammal species in both East and South Africa in the Early Pleistocene. The tooth falls well outside the P. robustus sample range, and comfortably within that for penecontemporaneous P. boisei. Analyses of sample range, distribution and variability suggest that it is possible, albeit unlikely to find a M(2) of this size in the current P. robustus sample. However, taphonomic agents - carnivore (particularly leopard) feeding behaviors - have likely skewed the size distribution of the Swartkrans and Drimolen P. robustus assemblage. In particular, assemblages of large-bodied mammals accumulated by leopards typically display high proportions of juveniles and smaller adults. The skew in the P. robustus sample is consistent with this type of assemblage. Morphological evidence in the form of cusp proportions is congruent with GDA-2 representing P. robustus rather than P. boisei. The comparatively small number of large-bodied mammal species common to both South and East Africa in the Early Pleistocene suggests a low probability of encountering an herbivorous australopith in both. Our results are most consistent with the interpretation of the Gondolin molar as a very large specimen of P. robustus. This, in turn, suggests that large, presumptive male, specimens are rare, and that the levels of size variation (sexual dimorphism) previously ascribed to this species are likely to be gross underestimates. Copyright © 2012 Elsevier Ltd. All rights reserved.

Co-Occurrence of Autism and Asthma in a Nationally-Representative Sample of Children in the United States

ERIC Educational Resources Information Center

Kotey, Stanley; Ertel, Karen; Whitcomb, Brian

2014-01-01

Few large epidemiological studies have examined the co-occurrence of autism and asthma. We performed a cross-sectional study to examine this association using the 2007 National Survey of Children's Health dataset (n = 77,951). We controlled for confounders and tested for autism-secondhand smoke interaction. Prevalence of asthma and autism…

Kids & Media @ the New Millennium: A Kaiser Family Foundation Report. A Comprehensive National Analysis of Children's Media Use. Executive Summary.

ERIC Educational Resources Information Center

Roberts, Donald F.

A study examined media use patterns among a large, nationally representative sample of children ages 2-18, and which explored how children choose and interact with the whole array of media available to them, including television, movies, computers, music, video games, radio, magazines, books, and newspapers. The goal was to provide a solid base…

Does Reading to Infants Benefit Their Cognitive Development at 9-Months-Old? An Investigation Using a Large Birth Cohort Survey

ERIC Educational Resources Information Center

Murray, Aisling; Egan, Suzanne M.

2014-01-01

This study uses a nationally representative sample of 9-month-old infants and their families from the Growing Up in Ireland (GUI) study to investigate if reading to infants is associated with higher scores on contemporaneous indicators of cognitive development independently of other language-based interactions between parent and infant, such as…

Teachers' Professional Orientation: An Empirical Examination of the Construct Validity Using the Results of Large-Scale Factor Analyses.

ERIC Educational Resources Information Center

Chauvin, Sheila W.; Ellett, Chad D.

The construct validity of the Attitudes of Professional Autonomy (APA) as a proxy measure of professional orientation was studied. The sample consisted of all teachers in 94 schools in 6 districts in Louisiana, closely representing the statewide distribution of all schools by level and socioeconomic status. Usable data were received from 1,921…

On the Success of Failure: A Reassessment of the Effects of Retention in the Primary Grades.

ERIC Educational Resources Information Center

Alexander, Karl L.; And Others

This book describes the context of school retention and evaluates its effects by tracking the experiences of a large representative sample of Baltimore (Maryland) school children from first grade through middle school. The first chapter is a discussion of major issues of retention such as: (1) why the topic is often pushed aside in schools; (2)…

The Structure and Determinants of Expected and Actual Starting Salaries of Higher Education Students in Germany: Identical or Different?

ERIC Educational Resources Information Center

Frick, Bernd; Maihaus, Michael

2016-01-01

Using two representative samples of some 74,000 students and 11,000 graduates, respectively, we analyse the accuracy of students' wage expectations given their individual characteristics. We find that students are aware of the effects of most of their own characteristics, as a large number of determinants of expected and realised salaries do not…

CALiPER Retail Lamps Study 3

DOE Office of Scientific and Technical Information (OSTI.GOV)

none,

2014-02-01

This is a special CALiPER report on LED lamps available through the retail marketplace and targeted toward general consumers. It follows similar reports published in 2011 and 2012 (products purchased in 2010 and 2011), and is intended as a continuation that identifies long-term trends. For this report, products were selected to investigate specific hypotheses, rather than represent a sample of the increasingly large retail LED market.

Extracurricular Activities: A Beneficial Extension of the Traditional Curriculum or a Subversion of Academic Goals.

ERIC Educational Resources Information Center

Marsh, Herbert W.

As part of the High School and Beyond study, students in a large nationally-representative sample were asked whether or not they had participated in each of a variety of extracurricular activities in their sophomore year (1980) and again in their senior year (1982) of high school. Data for 1984--2 years after the subjects graduated from high…

Demands of Social Change as a Function of the Political Context, Institutional Filters, and Psychosocial Resources

ERIC Educational Resources Information Center

Tomasik, Martin J.; Silbereisen, Rainer K.

2009-01-01

Individually experienced demands of current social change in the domains of work and family were assessed in a large sample of adults from two Western and two Eastern federal states of Germany. For each domain of life, a cumulated index was computed representing the load with highly endorsed demands and this was compared across political regions,…

State-space reduction and equivalence class sampling for a molecular self-assembly model.

PubMed

Packwood, Daniel M; Han, Patrick; Hitosugi, Taro

2016-07-01

Direct simulation of a model with a large state space will generate enormous volumes of data, much of which is not relevant to the questions under study. In this paper, we consider a molecular self-assembly model as a typical example of a large state-space model, and present a method for selectively retrieving 'target information' from this model. This method partitions the state space into equivalence classes, as identified by an appropriate equivalence relation. The set of equivalence classes H, which serves as a reduced state space, contains none of the superfluous information of the original model. After construction and characterization of a Markov chain with state space H, the target information is efficiently retrieved via Markov chain Monte Carlo sampling. This approach represents a new breed of simulation techniques which are highly optimized for studying molecular self-assembly and, moreover, serves as a valuable guideline for analysis of other large state-space models.

Organic Compounds and Trace Elements in Fish Tissue and Bed Sediment in the Delaware River Basin, New Jersey, Pennsylvania, New York, and Delaware, 1998-2000

USGS Publications Warehouse

Romanok, Kristin M.; Fischer, Jeffrey M.; Riva-Murray, Karen; Brightbill, Robin; Bilger, Michael

2006-01-01

As part of the National Water-Quality Assessment (NAWQA) program activities in the Delaware River Basin (DELR), samples of fish tissue from 21 sites and samples of bed sediment from 35 sites were analyzed for a suite of organic compounds and trace elements. The sampling sites, within subbasins ranging in size from 11 to 600 square miles, were selected to represent 5 main land-use categories in the DELR -forest, low-agricultural, agricultural, urban, and mixed use. Samples of both fish tissue and bed sediment were also collected from 4 'large-river' sites that represented drainage areas ranging from 1,300 to 6,800 square miles, areas in which the land is used for a variety of purposes. One or more of the organochlorine compounds-DDT and chlordane metabolites, polychlorinated biphenyls (total PCBs), and dieldrin- were detected frequently in samples collected over a wide geographic area. One or more of these compounds were detected in fish-tissue samples from 92 percent of the sites and in bed-sediment samples from 82 percent of the sites. Concentrations of total DDT, total chlordanes, total PCBs, and dieldrin in whole white suckers and in bed sediment were significantly related to urban/industrial basin characteristics, such as percentage of urban land use and population density. Semi-volatile organic compounds (SVOCs)-total polycyclic aromatic hydrocarbons (PAHs), total phthalates, and phenols- were detected frequently in bed-sediment samples. All three types of SVOCs were detected in samples from at least one site in each land-use category. The highest detection rates and concentrations typically were in samples from sites in the urban and mixed land-use categories, as well as from the large-river sites. Concentrations of total PAHs and total phthalates in bed-sediment samples were found to be statistically related to percentages of urban land use and to population density in the drainage areas represented by the sampling sites. The samples of fish tissue and bed sediment collected throughout the DELR were analyzed for a large suite of trace elements, but results of the analyses for eight elements-arsenic, cadmium, chromium, copper, lead, nickel, mercury, and zinc- that are considered contaminants of concern are described in this report. One or more of the eight trace elements were detected in samples from every fish tissue and bed-sediment sampling site, and all of the trace elements were detected in samples from 97 percent of the bed-sediment sites. The concentrations of organic compounds and trace elements in the DELR samples were compared to applicable guidelines for the protection of wildlife and other biological organisms. Concentrations of total DDT, total chlordanes, total PCBs, and dieldrin in fish-tissue samples from 14 sites exceeded one or more of the Wildlife Protective Guidelines established by the New York State Department of Environmental Conservation. Concentrations of one or more organic compounds in samples from 16 bed-sediment sites exceeded the Threshold Effects Concentrations (TEC) of the Canadian Sediment Quality Guidelines, and concentrations of one or more of the eight trace elements in samples from 38 bed-sediment sites exceeded the TEC. (The TEC is the concentration below which adverse biological effects in freshwater ecosystems are expected to be rare.) Concentrations of organic compounds in samples from some bed-sediment sites exceeded the Canadian Probable Effects Concentrations (PEC), and concentrations of trace elements in samples from 18 sites exceeded the PEC. (The PEC is the concentration above which adverse effects to biological organisms are expected to occur frequently). Concentrations of organic compounds and trace elements in samples from the DELR were compared to similar data from other NAWQA study units in the northeastern United States and also data from the Mobile River (Alabama) Basin and the Northern Rockies Intermontane Basin study units. Median concentrations of to

Iberian fish records in the vertebrate collection of the Museum of Zoology of the University of Navarra

PubMed Central

Rodeles, Amaia A.; Galicia, David; Miranda, Rafael

2016-01-01

The study of freshwater fish species biodiversity and community composition is essential for understanding river systems, the effects of human activities on rivers, and the changes these animals face. Conducting this type of research requires quantitative information on fish abundance, ideally with long-term series and fish body measurements. This Data Descriptor presents a collection of 12 datasets containing a total of 146,342 occurrence records of 41 freshwater fish species sampled in 233 localities of various Iberian river basins. The datasets also contain 148,749 measurement records (length and weight) for these fish. Data were collected in different sampling campaigns (from 1992 to 2015). Eleven datasets represent large projects conducted over several years, and another combines small sampling campaigns. The Iberian Peninsula contains high fish biodiversity, with numerous endemic species threatened by various menaces, such as water extraction and invasive species. These data may support the development of large biodiversity conservation studies. PMID:27727236

Iberian fish records in the vertebrate collection of the Museum of Zoology of the University of Navarra.

PubMed

Rodeles, Amaia A; Galicia, David; Miranda, Rafael

2016-10-11

The study of freshwater fish species biodiversity and community composition is essential for understanding river systems, the effects of human activities on rivers, and the changes these animals face. Conducting this type of research requires quantitative information on fish abundance, ideally with long-term series and fish body measurements. This Data Descriptor presents a collection of 12 datasets containing a total of 146,342 occurrence records of 41 freshwater fish species sampled in 233 localities of various Iberian river basins. The datasets also contain 148,749 measurement records (length and weight) for these fish. Data were collected in different sampling campaigns (from 1992 to 2015). Eleven datasets represent large projects conducted over several years, and another combines small sampling campaigns. The Iberian Peninsula contains high fish biodiversity, with numerous endemic species threatened by various menaces, such as water extraction and invasive species. These data may support the development of large biodiversity conservation studies.

The use of laser-induced fluorescence or ultraviolet detectors for sensitive and selective analysis of tobramycin or erythropoietin in complex samples

NASA Astrophysics Data System (ADS)

Ahmed, Hytham M.; Ebeid, Wael B.

2015-05-01

Complex samples analysis is a challenge in pharmaceutical and biopharmaceutical analysis. In this work, tobramycin (TOB) analysis in human urine samples and recombinant human erythropoietin (rhEPO) analysis in the presence of similar protein were selected as representative examples of such samples analysis. Assays of TOB in urine samples are difficult because of poor detectability. Therefore laser induced fluorescence detector (LIF) was combined with a separation technique, micellar electrokinetic chromatography (MEKC), to determine TOB through derivatization with fluorescein isothiocyanate (FITC). Borate was used as background electrolyte (BGE) with negative-charged mixed micelles as additive. The method was successively applied to urine samples. The LOD and LOQ for Tobramycin in urine were 90 and 200 ng/ml respectively and recovery was >98% (n = 5). All urine samples were analyzed by direct injection without sample pre-treatment. Another use of hyphenated analytical technique, capillary zone electrophoresis (CZE) connected to ultraviolet (UV) detector was also used for sensitive analysis of rhEPO at low levels (2000 IU) in the presence of large amount of human serum albumin (HSA). Analysis of rhEPO was achieved by the use of the electrokinetic injection (EI) with discontinuous buffers. Phosphate buffer was used as BGE with metal ions as additive. The proposed method can be used for the estimation of large number of quality control rhEPO samples in a short period.

Project Hyreus: Mars Sample Return Mission Utilizing in Situ Propellant Production

NASA Technical Reports Server (NTRS)

Bruckner, A. P.; Thill, Brian; Abrego, Anita; Koch, Amber; Kruse, Ross; Nicholson, Heather; Nill, Laurie; Schubert, Heidi; Schug, Eric; Smith, Brian

1993-01-01

Project Hyreus is an unmanned Mars sample return mission that utilizes propellants manufactured in situ from the Martian atmosphere for the return voyage. A key goal of the mission is to demonstrate the considerable benefits of using indigenous resources and to test the viability of this approach as a precursor to manned Mars missions. The techniques, materials, and equipment used in Project Hyreus represent those that are currently available or that could be developed and readied in time for the proposed launch date in 2003. Project Hyreus includes such features as a Mars-orbiting satellite equipped with ground-penetrating radar, a large rover capable of sample gathering and detailed surface investigations, and a planetary science array to perform on-site research before samples are returned to Earth. Project Hyreus calls for the Mars Landing Vehicle to land in the Mangala Valles region of Mars, where it will remain for approximately 1.5 years. Methane and oxygen propellant for the Earth return voyage will be produced using carbon dioxide from the Martian atmosphere and a small supply of hydrogen brought from Earth. This process is key to returning a large Martian sample to Earth with a single Earth launch.

Project Hyreus: Mars sample return mission utilizing in situ propellant production

NASA Technical Reports Server (NTRS)

Abrego, Anita; Bair, Chris; Hink, Anthony; Kim, Jae; Koch, Amber; Kruse, Ross; Ngo, Dung; Nicholson, Heather; Nill, Laurie; Perras, Craig

1993-01-01

Project Hyreus is an unmanned Mars sample return mission that utilizes propellants manufactured in situ from the Martian atmosphere for the return voyage. A key goal of the mission is to demonstrate the considerable benefits of using indigenous resources and to test the viability of this approach as a precursor to manned Mars missions. The techniques, materials, and equipment used in Project Hyreus represent those that are currently available or that could be developed and readied in time for the proposed launch date in 2003. Project Hyreus includes such features as a Mars-orbiting satellite equipped with ground-penetrating radar, a large rover capable of sample gathering and detailed surface investigations, and a planetary science array to perform on-site research before samples are returned to Earth. Project Hyreus calls for the Mars Landing Vehicle to land in the Mangala Valles region of Mars, where it will remain for approximately 1.5 years. Methane and oxygen propellant for the Earth return voyage will be produced using carbon dioxide from the Martian atmosphere and a small supply of hydrogen brought from Earth. This process is key to returning a large Martian sample to Earth with a single Earth launch.

Microbiome of the upper troposphere: species composition and prevalence, effects of tropical storms, and atmospheric implications.

PubMed

DeLeon-Rodriguez, Natasha; Lathem, Terry L; Rodriguez-R, Luis M; Barazesh, James M; Anderson, Bruce E; Beyersdorf, Andreas J; Ziemba, Luke D; Bergin, Michael; Nenes, Athanasios; Konstantinidis, Konstantinos T

2013-02-12

The composition and prevalence of microorganisms in the middle-to-upper troposphere (8-15 km altitude) and their role in aerosol-cloud-precipitation interactions represent important, unresolved questions for biological and atmospheric science. In particular, airborne microorganisms above the oceans remain essentially uncharacterized, as most work to date is restricted to samples taken near the Earth's surface. Here we report on the microbiome of low- and high-altitude air masses sampled onboard the National Aeronautics and Space Administration DC-8 platform during the 2010 Genesis and Rapid Intensification Processes campaign in the Caribbean Sea. The samples were collected in cloudy and cloud-free air masses before, during, and after two major tropical hurricanes, Earl and Karl. Quantitative PCR and microscopy revealed that viable bacterial cells represented on average around 20% of the total particles in the 0.25- to 1-μm diameter range and were at least an order of magnitude more abundant than fungal cells, suggesting that bacteria represent an important and underestimated fraction of micrometer-sized atmospheric aerosols. The samples from the two hurricanes were characterized by significantly different bacterial communities, revealing that hurricanes aerosolize a large amount of new cells. Nonetheless, 17 bacterial taxa, including taxa that are known to use C1-C4 carbon compounds present in the atmosphere, were found in all samples, indicating that these organisms possess traits that allow survival in the troposphere. The findings presented here suggest that the microbiome is a dynamic and underappreciated aspect of the upper troposphere with potentially important impacts on the hydrological cycle, clouds, and climate.

Sample presentation, sources of error and future perspectives on the application of vibrational spectroscopy in the wine industry.

PubMed

Cozzolino, Daniel

2015-03-30

Vibrational spectroscopy encompasses a number of techniques and methods including ultra-violet, visible, Fourier transform infrared or mid infrared, near infrared and Raman spectroscopy. The use and application of spectroscopy generates spectra containing hundreds of variables (absorbances at each wavenumbers or wavelengths), resulting in the production of large data sets representing the chemical and biochemical wine fingerprint. Multivariate data analysis techniques are then required to handle the large amount of data generated in order to interpret the spectra in a meaningful way in order to develop a specific application. This paper focuses on the developments of sample presentation and main sources of error when vibrational spectroscopy methods are applied in wine analysis. Recent and novel applications will be discussed as examples of these developments. © 2014 Society of Chemical Industry.

Jaccard distance based weighted sparse representation for coarse-to-fine plant species recognition.

PubMed

Zhang, Shanwen; Wu, Xiaowei; You, Zhuhong

2017-01-01

Leaf based plant species recognition plays an important role in ecological protection, however its application to large and modern leaf databases has been a long-standing obstacle due to the computational cost and feasibility. Recognizing such limitations, we propose a Jaccard distance based sparse representation (JDSR) method which adopts a two-stage, coarse to fine strategy for plant species recognition. In the first stage, we use the Jaccard distance between the test sample and each training sample to coarsely determine the candidate classes of the test sample. The second stage includes a Jaccard distance based weighted sparse representation based classification(WSRC), which aims to approximately represent the test sample in the training space, and classify it by the approximation residuals. Since the training model of our JDSR method involves much fewer but more informative representatives, this method is expected to overcome the limitation of high computational and memory costs in traditional sparse representation based classification. Comparative experimental results on a public leaf image database demonstrate that the proposed method outperforms other existing feature extraction and SRC based plant recognition methods in terms of both accuracy and computational speed.

The Structure of The Extended Psychosis Phenotype in Early Adolescence—A Cross-sample Replication

PubMed Central

Wigman, Johanna T. W.; Vollebergh, Wilma A. M.; Raaijmakers, Quinten A. W.; Iedema, Jurjen; van Dorsselaer, Saskia; Ormel, Johan; Verhulst, Frank C.; van Os, Jim

2011-01-01

The extended psychosis phenotype, or the expression of nonclinical positive psychotic experiences, is already prevalent in adolescence and has a dose-response risk relationship with later psychotic disorder. In 2 large adolescent general population samples (n = 5422 and n = 2230), prevalence and structure of the extended psychosis phenotype was investigated. Positive psychotic experiences, broadly defined, were reported by the majority of adolescents. Exploratory analysis with Structural Equation Modelling (Exploratory Factor Analysis followed by Confirmatory Factor Analysis [CFA]) in sample 1 suggested that psychotic experiences were best represented by 5 underlying dimensions; CFA in sample 2 provided a replication of this model. Dimensions were labeled Hallucinations, Delusions, Paranoia, Grandiosity, and Paranormal beliefs. Prevalences differed strongly, Hallucinations having the lowest and Paranoia having the highest rates. Girls reported more experiences on all dimensions, except Grandiosity, and from age 12 to 16 years rates increased. Hallucinations, Delusions, and Paranoia, but not Grandiosity and Paranormal beliefs, were associated with distress and general measures of psychopathology. Thus, only some of the dimensions of the extended psychosis phenotype in young people may represent a continuum with more severe psychopathology and predict later psychiatric disorder. PMID:20044595

Reduction in training time of a deep learning model in detection of lesions in CT

NASA Astrophysics Data System (ADS)

Makkinejad, Nazanin; Tajbakhsh, Nima; Zarshenas, Amin; Khokhar, Ashfaq; Suzuki, Kenji

2018-02-01

Deep learning (DL) emerged as a powerful tool for object detection and classification in medical images. Building a well-performing DL model, however, requires a huge number of images for training, and it takes days to train a DL model even on a cutting edge high-performance computing platform. This study is aimed at developing a method for selecting a "small" number of representative samples from a large collection of training samples to train a DL model for the could be used to detect polyps in CT colonography (CTC), without compromising the classification performance. Our proposed method for representative sample selection (RSS) consists of a K-means clustering algorithm. For the performance evaluation, we applied the proposed method to select samples for the training of a massive training artificial neural network based DL model, to be used for the classification of polyps and non-polyps in CTC. Our results show that the proposed method reduce the training time by a factor of 15, while maintaining the classification performance equivalent to the model trained using the full training set. We compare the performance using area under the receiveroperating- characteristic curve (AUC).

Conceptual data sampling for breast cancer histology image classification.

PubMed

Rezk, Eman; Awan, Zainab; Islam, Fahad; Jaoua, Ali; Al Maadeed, Somaya; Zhang, Nan; Das, Gautam; Rajpoot, Nasir

2017-10-01

Data analytics have become increasingly complicated as the amount of data has increased. One technique that is used to enable data analytics in large datasets is data sampling, in which a portion of the data is selected to preserve the data characteristics for use in data analytics. In this paper, we introduce a novel data sampling technique that is rooted in formal concept analysis theory. This technique is used to create samples reliant on the data distribution across a set of binary patterns. The proposed sampling technique is applied in classifying the regions of breast cancer histology images as malignant or benign. The performance of our method is compared to other classical sampling methods. The results indicate that our method is efficient and generates an illustrative sample of small size. It is also competing with other sampling methods in terms of sample size and sample quality represented in classification accuracy and F1 measure. Copyright © 2017 Elsevier Ltd. All rights reserved.

ClustENM: ENM-Based Sampling of Essential Conformational Space at Full Atomic Resolution

PubMed Central

Kurkcuoglu, Zeynep; Bahar, Ivet; Doruker, Pemra

2016-01-01

Accurate sampling of conformational space and, in particular, the transitions between functional substates has been a challenge in molecular dynamic (MD) simulations of large biomolecular systems. We developed an Elastic Network Model (ENM)-based computational method, ClustENM, for sampling large conformational changes of biomolecules with various sizes and oligomerization states. ClustENM is an iterative method that combines ENM with energy minimization and clustering steps. It is an unbiased technique, which requires only an initial structure as input, and no information about the target conformation. To test the performance of ClustENM, we applied it to six biomolecular systems: adenylate kinase (AK), calmodulin, p38 MAP kinase, HIV-1 reverse transcriptase (RT), triosephosphate isomerase (TIM), and the 70S ribosomal complex. The generated ensembles of conformers determined at atomic resolution show good agreement with experimental data (979 structures resolved by X-ray and/or NMR) and encompass the subspaces covered in independent MD simulations for TIM, p38, and RT. ClustENM emerges as a computationally efficient tool for characterizing the conformational space of large systems at atomic detail, in addition to generating a representative ensemble of conformers that can be advantageously used in simulating substrate/ligand-binding events. PMID:27494296

Trace Gas Analyzer (TGA) program

NASA Technical Reports Server (NTRS)

1977-01-01

The design, fabrication, and test of a breadboard trace gas analyzer (TGA) is documented. The TGA is a gas chromatograph/mass spectrometer system. The gas chromatograph subsystem employs a recirculating hydrogen carrier gas. The recirculation feature minimizes the requirement for transport and storage of large volumes of carrier gas during a mission. The silver-palladium hydrogen separator which permits the removal of the carrier gas and its reuse also decreases vacuum requirements for the mass spectrometer since the mass spectrometer vacuum system need handle only the very low sample pressure, not sample plus carrier. System performance was evaluated with a representative group of compounds.

The grapevine expression atlas reveals a deep transcriptome shift driving the entire plant into a maturation program.

PubMed

Fasoli, Marianna; Dal Santo, Silvia; Zenoni, Sara; Tornielli, Giovanni Battista; Farina, Lorenzo; Zamboni, Anita; Porceddu, Andrea; Venturini, Luca; Bicego, Manuele; Murino, Vittorio; Ferrarini, Alberto; Delledonne, Massimo; Pezzotti, Mario

2012-09-01

We developed a genome-wide transcriptomic atlas of grapevine (Vitis vinifera) based on 54 samples representing green and woody tissues and organs at different developmental stages as well as specialized tissues such as pollen and senescent leaves. Together, these samples expressed ∼91% of the predicted grapevine genes. Pollen and senescent leaves had unique transcriptomes reflecting their specialized functions and physiological status. However, microarray and RNA-seq analysis grouped all the other samples into two major classes based on maturity rather than organ identity, namely, the vegetative/green and mature/woody categories. This division represents a fundamental transcriptomic reprogramming during the maturation process and was highlighted by three statistical approaches identifying the transcriptional relationships among samples (correlation analysis), putative biomarkers (O2PLS-DA approach), and sets of strongly and consistently expressed genes that define groups (topics) of similar samples (biclustering analysis). Gene coexpression analysis indicated that the mature/woody developmental program results from the reiterative coactivation of pathways that are largely inactive in vegetative/green tissues, often involving the coregulation of clusters of neighboring genes and global regulation based on codon preference. This global transcriptomic reprogramming during maturation has not been observed in herbaceous annual species and may be a defining characteristic of perennial woody plants.

Protocol and methodology of Study epidemiological mental health in Andalusia: PISMA-ep.

PubMed

Cervilla, Jorge A; Ruiz, Isabel; Rodríguez-Barranco, Miguel; Rivera, Margarita; Ibáñez-Casas, Inmaculada; Molina, Esther; Valmisa, Eulalio; Carmona-Calvo, José; Moreno-Küstner, Berta; Muñoz-Negro, José Eduardo; Ching-López, Ana; Gutiérrez, Blanca

This is the general methods describing paper of a cross-sectional study that aims to detect the prevalence of major mental disorders in Andalusia (Southern Spain), and their correlates or potential risk factors, using a large representative sample of community-dwelling adults. This is a cross-sectional study. We undertook a multistage sampling using different standard stratification levels and aimed to interview 4,518 randomly selected participants living in all 8 provinces of the Andalusian region utilizing a door-knocking approach. The Spanish version of the MINI International Neuropsychiatric Interview, a valid screening instrument ascertaining ICD-10/DSM-IV compatible mental disorder diagnoses was used as our main diagnostic tool. A large battery of other instruments was used to explore global functionality, medical comorbidity, personality traits, cognitive function and exposure to psychosocial potential risk factors. A saliva sample for DNA extraction was also obtained for a sub-genetic study. The interviews were administered and completed by fully trained interviewers, despite most tools used are compatible with lay interviewer use. A total of 3,892 (70.8%) of 5,496 initially attempted households had to be substituted for equivalent ones due to either no response (37.7%) or not fulfilling the required participant quota (33%). Thence, out of 5,496 eligible participants finally approached, 4,507 (83.7%) agreed to take part in the study, completed the interview and were finally included in the study (n=4,507) and 4,286 (78%) participants also agreed and consented to provide a saliva sample for DNA study. On the other hand, 989 (16.3%) approached potential participants refused to take part in the study. This is the largest mental health epidemiological study developed in the region of Spain (Andalusia). The response rates and representativeness of the sample obtained are fairly high. The method is particularly comprehensive for this sort of studies and includes both, personality and cognitive assessments, as well as a large array of bio-psycho-social risk measures. Copyright © 2016 SEP y SEPB. Publicado por Elsevier España, S.L.U. All rights reserved.

Deriving spatial patterns from a novel database of volcanic rock geochemistry in the Virunga Volcanic Province, East African Rift

NASA Astrophysics Data System (ADS)

Poppe, Sam; Barette, Florian; Smets, Benoît; Benbakkar, Mhammed; Kervyn, Matthieu

2016-04-01

The Virunga Volcanic Province (VVP) is situated within the western branch of the East-African Rift. The geochemistry and petrology of its' volcanic products has been studied extensively in a fragmented manner. They represent a unique collection of silica-undersaturated, ultra-alkaline and ultra-potassic compositions, displaying marked geochemical variations over the area occupied by the VVP. We present a novel spatially-explicit database of existing whole-rock geochemical analyses of the VVP volcanics, compiled from international publications, (post-)colonial scientific reports and PhD theses. In the database, a total of 703 geochemical analyses of whole-rock samples collected from the 1950s until recently have been characterised with a geographical location, eruption source location, analytical results and uncertainty estimates for each of these categories. Comparative box plots and Kruskal-Wallis H tests on subsets of analyses with contrasting ages or analytical methods suggest that the overall database accuracy is consistent. We demonstrate how statistical techniques such as Principal Component Analysis (PCA) and subsequent cluster analysis allow the identification of clusters of samples with similar major-element compositions. The spatial patterns represented by the contrasting clusters show that both the historically active volcanoes represent compositional clusters which can be identified based on their contrasted silica and alkali contents. Furthermore, two sample clusters are interpreted to represent the most primitive, deep magma source within the VVP, different from the shallow magma reservoirs that feed the eight dominant large volcanoes. The samples from these two clusters systematically originate from locations which 1. are distal compared to the eight large volcanoes and 2. mostly coincide with the surface expressions of rift faults or NE-SW-oriented inherited Precambrian structures which were reactivated during rifting. The lava from the Mugogo eruption of 1957 belongs to these primitive clusters and is the only known to have erupted outside the current rift valley in historical times. We thus infer there is a distributed hazard of vent opening susceptibility additional to the susceptibility associated with the main Virunga edifices. This study suggests that the statistical analysis of such geochemical database may help to understand complex volcanic plumbing systems and the spatial distribution of volcanic hazards in active and poorly known volcanic areas such as the Virunga Volcanic Province.

Scene recognition based on integrating active learning with dictionary learning

NASA Astrophysics Data System (ADS)

Wang, Chengxi; Yin, Xueyan; Yang, Lin; Gong, Chengrong; Zheng, Caixia; Yi, Yugen

2018-04-01

Scene recognition is a significant topic in the field of computer vision. Most of the existing scene recognition models require a large amount of labeled training samples to achieve a good performance. However, labeling image manually is a time consuming task and often unrealistic in practice. In order to gain satisfying recognition results when labeled samples are insufficient, this paper proposed a scene recognition algorithm named Integrating Active Learning and Dictionary Leaning (IALDL). IALDL adopts projective dictionary pair learning (DPL) as classifier and introduces active learning mechanism into DPL for improving its performance. When constructing sampling criterion in active learning, IALDL considers both the uncertainty and representativeness as the sampling criteria to effectively select the useful unlabeled samples from a given sample set for expanding the training dataset. Experiment results on three standard databases demonstrate the feasibility and validity of the proposed IALDL.

Prevalence of internet addiction and its risk and protective factors in a representative sample of senior high school students in Taiwan.

PubMed

Lin, Min-Pei; Wu, Jo Yung-Wei; You, Jianing; Hu, Wei-Hsuan; Yen, Cheng-Fang

2018-01-01

The aim of this study investigated the prevalence of Internet addiction (IA) in a large representative sample of secondary school students and identified the risk and protective factors. Using a crosssectional design, 2170 participants were recruited from senior high schools throughout Taiwan using both stratified and cluster sampling. The prevalence of IA was 17.4% (95% confidence interval, 15.8%-19.0%). High impulsivity, low refusal self-efficacy of Internet use, high positive outcome expectancy of Internet use, high disapproving attitude of Internet use by others, depressive symptoms, low subjective well-being, high frequency of others' invitation to Internet use, and high virtual social support was all independently predictive in the logistic regression analysis. The prevalence of IA among secondary school students in Taiwan was high. Results from this study can be used to help educational agencies and mental health organizations create policies and design programs that will help in the prevention of IA in adolescents. Copyright © 2017 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Sexual difficulties in people living with HIV in France--results from a large representative sample of outpatients attending French hospitals (ANRS-EN12-VESPA).

PubMed

Bouhnik, Anne-Déborah; Préau, Marie; Schiltz, Marie-Ange; Obadia, Yolande; Spire, Bruno

2008-07-01

We analysed sexual difficulties in a nationally representative sample of HIV-infected outpatients in France. Analyses were restricted to the 1,812 HIV-treated participants who reported at least one sexual partner during the 12 months prior to the study. The sample included 40.6% homosexual men and 24.4% women; 68.1% had a steady partner and 48.2% reported casual partners. Sexual difficulties were reported by 33.3% of the selected individuals and were more frequent in those with low sexual activity. Immuno-virological outcomes were not associated with sexual difficulties. After multiple adjustment for sexual frequency and antidepressant consumption, it was found that a larger HIV-network, reporting HIV-discrimination from friends and/or sexual partners, suffering from lipodystrophy and reporting very disturbing HIV-related symptoms were all significantly associated with sexual difficulties. HIV and HIV-treatment experience are associated with sexual difficulties. Psychological support focused on HIV-experience should be tested as a possible tool for improving sexual quality of life.

A curated compendium of monocyte transcriptome datasets of relevance to human monocyte immunobiology research

PubMed Central

Rinchai, Darawan; Boughorbel, Sabri; Presnell, Scott; Quinn, Charlie; Chaussabel, Damien

2016-01-01

Systems-scale profiling approaches have become widely used in translational research settings. The resulting accumulation of large-scale datasets in public repositories represents a critical opportunity to promote insight and foster knowledge discovery. However, resources that can serve as an interface between biomedical researchers and such vast and heterogeneous dataset collections are needed in order to fulfill this potential. Recently, we have developed an interactive data browsing and visualization web application, the Gene Expression Browser (GXB). This tool can be used to overlay deep molecular phenotyping data with rich contextual information about analytes, samples and studies along with ancillary clinical or immunological profiling data. In this note, we describe a curated compendium of 93 public datasets generated in the context of human monocyte immunological studies, representing a total of 4,516 transcriptome profiles. Datasets were uploaded to an instance of GXB along with study description and sample annotations. Study samples were arranged in different groups. Ranked gene lists were generated based on relevant group comparisons. This resource is publicly available online at http://monocyte.gxbsidra.org/dm3/landing.gsp. PMID:27158452

The use of Stable Isotopes to Assess Climatic Controls on Groundwater Recharge in the Southern Sacramento Mountains, New Mexico

NASA Astrophysics Data System (ADS)

Newton, B. T.; Timmons, S. S.; Rawling, G. C.; Kludt, T.; Eastoe, C. J.

2008-12-01

We used the stable isotopes of hydrogen and oxygen to relate the temporal variability of groundwater recharge to climatic conditions in the southern Sacramento Mountains as a part of a larger regional hydrogeologic study. The southern Sacramento Mountains are the primary recharge source not only to local aquifers, but also to the Lower Pecos River Basin, the Roswell Artesian aquifer and aquifers in the Salt Basin. Aquifers in the study area mainly consist of fractured limestone. In years prior to 2006, groundwater levels within the study area showed a steady decline. We observed a significant increase in regional groundwater levels and spring discharge during and shortly after the unusually wet 2006 monsoon season. We developed a local meteoric water line (LMWL) in δ18O vs. δD space based on precipitation samples collected from several different elevations over a period of two years. The stable isotopic compositions of streams during base flow conditions define an evaporation line with a slope of 5.5 that intersects the LMWL in the region that represents winter precipitation. Spring and well samples collected in 2003 and spring samples collected in 2008 exhibit isotopic compositions that plot near the evaporation line, indicating that groundwater recharge is largely snow melt that has subsequently undergone evaporation in local streams. After the unusually wet 2006 monsoon season, the isotopic compositions of springs sampled in fall of 2006 and wells sampled in spring of 2007 deviated from the evaporation line, plotting closer to the LMWL. This observed isotopic trend is thought to represent a large input of 2006 monsoon precipitation to the groundwater system via relatively short fracture-dominated flow paths. Stable isotope results indicate that while snow melt is probably the main source of groundwater recharge in the southern Sacramento Mountains, as exhibited by the 2003 and 2008 samples, above average summer precipitation events, such as in 2006, can also contribute to significant groundwater recharge.

Lithologic distribution and geologic history of the Apollo 17 site: The record in soils and small rock particles from the highland massifs

NASA Astrophysics Data System (ADS)

Jolliff, Bradley L.; Rockow, Kaylynn M.; Korotev, Randy L.; Haskin, Larry A.

1996-01-01

Through analysis by instrumental neutron activation (INAA) of 789 individual lithic fragments from the 2 mm-4 mm grain-size fractions of five Apollo 17 soil samples (72443, 72503, 73243, 76283, and 76503) and petrographic examination of a subset, we have determined the diversity and proportions of rock types recorded within soils from the highland massifs. The distribution of rock types at the site, as recorded by lithic fragments in the soils, is an alternative to the distribution inferred from the limited number of large rock samples. The compositions and proportions of 2 mm-4 mm fragments provide a bridge between compositions of <1 mm fines, and types and proportions of rocks observed in large collected breccias and their clasts. The 2 mm-4 mm fraction of soil from South Massif, represented by an unbiased set of lithic fragments from station-2 samples 72443 and 72503, consists of 71% noritic impact-melt breccia, 7% incompatible-trace-element-(ITE)-poor highland rock types (mainly granulitic breccias), 19% agglutinates and regolith breccias, 1% high-Ti mare basalt, and 2% others (very-low-Ti (VLT) basalt, monzogabbro breccia, and metal). In contrast, the 2 mm-4 mm fraction of a soil from the North Massif, represented by an unbiased set of lithic fragments from station-6 sample 76503, has a greater proportion of ITE-poor highland rock types and mare-basalt fragments: it consists of 29% ITE-poor highland rock types (mainly granulitic breccias and troctolitic anorthosite), 25% impact-melt breccia, 13% high-Ti mare basalt, 31% agglutinates and regolith breccias, 1% orange glass and related breccia, and 1% others. Based on a comparison of mass-weighted mean compositions of the lithic fragments with compositions of soil fines from all Apollo 17 highland stations, differences between the station-2 and station-6 samples are representative of differences between available samples from the two massifs. From the distribution of different rock types and their compositions, we conclude the following: (1) North-Massif and South-Massif soil samples differ significantly in types and proportions of ITE-poor highland components and ITE-rich impact-melt-breccia components. These differences reflect crudely layered massifs and known local geology. The greater percentage of impact-melt breccia in the South-Massif light-mantle soil stems from derivation of the light mantle from the top of the massif, which apparently is richer in noritic impact-melt breccia than are lower parts of the massifs. (2) At station 2, the 2 mm-4 mm grain-size fraction is enriched in impact-melt breccias compared to the <1 mm fraction, suggesting that the <1 mm fraction within the light mantle has a greater proportion of lithologies such as granulitic breccias which are more prevalent lower in the massifs and which we infer to be older (pre-basin) highland components. (3) Soil from station 6, North Massif, contains magnesian troctolitic anorthosite, which is a component that is rare in station-2 South-Massif soils. (4) Compositional differences between poikilitic impact-melt breccias from the two massifs suggest broad-scale heterogeneity in impact-melt breccia interpreted by most investigators to be ejecta from the Serenitatis basin. We have found rock types not previously recognized or uncommon at the Apollo 17 site. These include (1) ITE-rich impact-melt breccias that are compositionally distinct from previously recognized "aphanitic" and "poikilitic" groups at Apollo 17; (2) regolith breccias that are free of mare components and poor in impact melt of the types associated with the main melt-breccia groups, and that, if those groups derive from the Serenitatis impact, may represent the pre-Serenitatis surface; (3) several VLT basalts, including an unusual very-high-K basaltic breccia; (4) orange-glass regolith breccias; (5) aphanitic-matrix melt breccias at station 6; (6) fragments of alkali-rich composition, including alkali anorthosite, and monzogabbro; (7) one fragment of 72275-type KREEP basalt from station 3; (8) seven lithic fragments of ferroan-anorthositic-suite rocks; and (9) a fragment of metal, possibly from an L chondrite. Some of these lithologies have been found only as lithic fragments in the soils and not among the large rock samples. In contrast, we have not found among the 2 mm-4 mm lithic fragments individual samples of certain lithologies that have been recognized as clasts in breccias (e.g., dunite and spinel troctolite). The diversity of lithologic information contained in the lithic fragments of these soils nearly equals that found among large rock samples, and most information bearing on petrographic relationships is maintained, even in such small samples. Given a small number of large samples for "petrologic ground truth," small lithic fragments contained in soil "scoop" samples can provide the basis for interpreting the diversity of rock types and their proportions in remotely sensed geologic units. They should be considered essential targets for future automated sample-analysis and sample-return missions.

Paleobiology and comparative morphology of a late Neandertal sample from El Sidron, Asturias, Spain.

PubMed

Rosas, Antonio; Martínez-Maza, Cayetana; Bastir, Markus; García-Tabernero, Antonio; Lalueza-Fox, Carles; Huguet, Rosa; Ortiz, José Eugenio; Julià, Ramón; Soler, Vicente; de Torres, Trinidad; Martínez, Enrique; Cañaveras, Juan Carlos; Sánchez-Moral, Sergio; Cuezva, Soledad; Lario, Javier; Santamaría, David; de la Rasilla, Marco; Fortea, Javier

2006-12-19

Fossil evidence from the Iberian Peninsula is essential for understanding Neandertal evolution and history. Since 2000, a new sample approximately 43,000 years old has been systematically recovered at the El Sidrón cave site (Asturias, Spain). Human remains almost exclusively compose the bone assemblage. All of the skeletal parts are preserved, and there is a moderate occurrence of Middle Paleolithic stone tools. A minimum number of eight individuals are represented, and ancient mtDNA has been extracted from dental and osteological remains. Paleobiology of the El Sidrón archaic humans fits the pattern found in other Neandertal samples: a high incidence of dental hypoplasia and interproximal grooves, yet no traumatic lesions are present. Moreover, unambiguous evidence of human-induced modifications has been found on the human remains. Morphologically, the El Sidrón humans show a large number of Neandertal lineage-derived features even though certain traits place the sample at the limits of Neandertal variation. Integrating the El Sidrón human mandibles into the larger Neandertal sample reveals a north-south geographic patterning, with southern Neandertals showing broader faces with increased lower facial heights. The large El Sidrón sample therefore augments the European evolutionary lineage fossil record and supports ecogeographical variability across Neandertal populations.

Automated liver sampling using a gradient dual-echo Dixon-based technique.

PubMed

Bashir, Mustafa R; Dale, Brian M; Merkle, Elmar M; Boll, Daniel T

2012-05-01

Magnetic resonance spectroscopy of the liver requires input from a physicist or physician at the time of acquisition to insure proper voxel selection, while in multiecho chemical shift imaging, numerous regions of interest must be manually selected in order to ensure analysis of a representative portion of the liver parenchyma. A fully automated technique could improve workflow by selecting representative portions of the liver prior to human analysis. Complete volumes from three-dimensional gradient dual-echo acquisitions with two-point Dixon reconstruction acquired at 1.5 and 3 T were analyzed in 100 subjects, using an automated liver sampling algorithm, based on ratio pairs calculated from signal intensity image data as fat-only/water-only and log(in-phase/opposed-phase) on a voxel-by-voxel basis. Using different gridding variations of the algorithm, the average correct liver volume samples ranged from 527 to 733 mL. The average percentage of sample located within the liver ranged from 95.4 to 97.1%, whereas the average incorrect volume selected was 16.5-35.4 mL (2.9-4.6%). Average run time was 19.7-79.0 s. The algorithm consistently selected large samples of the hepatic parenchyma with small amounts of erroneous extrahepatic sampling, and run times were feasible for execution on an MRI system console during exam acquisition. Copyright © 2011 Wiley Periodicals, Inc.

Allogenic and Autogenic Signals in the Detrital Zircon U-Pb Record of the Deep-Sea Bengal Fan

NASA Astrophysics Data System (ADS)

Blum, M. D.; Rogers, K. G.; Gleason, J. D.; Najman, Y.

2017-12-01

The Himalayan-sourced Ganges-Brahmaputra river system and the deep-sea Bengal Fan represent Earth's largest sediment-dispersal system. This presentation summarizes a new detrital zircon U-Pb (DZ) provenance record from the Bengal Fan from cores collected during IODP Expedition 354, with coring sites located 1350 km downdip from the shelf margin. Each of our 15 samples were collected from medium- to fine-grained turbidite sand and, based on shipboard biostratigraphic analyses, our samples are late Miocene to late Pleistocene in age. Each sample was analyzed by LA-ICPMS at the Arizona Laserchron facility, with an average of n=270 concordant U-Pb ages per sample. Our goals are to use these data to evaluate the influence of allogenic controls vs. autogenic processes on signal propagation from source-to-sink. At the first order, large-scale sediment transfer to the Bengal Fan clearly records the strong tectonic and climatic forcing associated with the Himalayas and Ganges-Brahmaputra system: after up to 2500 km of river transport, and 1350 km of transport in turbidity currents, the DZ record faithfully represents Himalayan source terrains. The sand-rich turbidite part of the record is nevertheless biased towards glacial periods when rivers extended across the shelf in response to climate-forced sea-level fall, and discharged directly to slope canyons. However, only part of the Bengal Fan DZ record represents either the Ganges or the Brahmaputra, with most samples representing varying degrees of mixing of sediments from the two systems: this mixing, or the lack thereof, represents the signal of autogenic avulsions on the delta plain that result in the two river systems delivering sediment separately to the shelf margin, or together as they do today. Within the allogenic framework established by tectonic processes, the climatic system, and global climate-forced sea-level change, the DZ U-Pb record of sediment mixing or the lack thereof provides a fingerprint of autogenic avulsions on signal transfer from source-to-sink in the world's largest sediment-dispersal system.

40 CFR Appendix I to Part 261 - Representative Sampling Methods

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Representative Sampling Methods I...—Representative Sampling Methods The methods and equipment used for sampling waste materials will vary with the form and consistency of the waste materials to be sampled. Samples collected using the sampling...

40 CFR Appendix I to Part 261 - Representative Sampling Methods

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 26 2011-07-01 2011-07-01 false Representative Sampling Methods I...—Representative Sampling Methods The methods and equipment used for sampling waste materials will vary with the form and consistency of the waste materials to be sampled. Samples collected using the sampling...

Geostatistical Sampling Methods for Efficient Uncertainty Analysis in Flow and Transport Problems

NASA Astrophysics Data System (ADS)

Liodakis, Stylianos; Kyriakidis, Phaedon; Gaganis, Petros

2015-04-01

In hydrogeological applications involving flow and transport of in heterogeneous porous media the spatial distribution of hydraulic conductivity is often parameterized in terms of a lognormal random field based on a histogram and variogram model inferred from data and/or synthesized from relevant knowledge. Realizations of simulated conductivity fields are then generated using geostatistical simulation involving simple random (SR) sampling and are subsequently used as inputs to physically-based simulators of flow and transport in a Monte Carlo framework for evaluating the uncertainty in the spatial distribution of solute concentration due to the uncertainty in the spatial distribution of hydraulic con- ductivity [1]. Realistic uncertainty analysis, however, calls for a large number of simulated concentration fields; hence, can become expensive in terms of both time and computer re- sources. A more efficient alternative to SR sampling is Latin hypercube (LH) sampling, a special case of stratified random sampling, which yields a more representative distribution of simulated attribute values with fewer realizations [2]. Here, term representative implies realizations spanning efficiently the range of possible conductivity values corresponding to the lognormal random field. In this work we investigate the efficiency of alternative methods to classical LH sampling within the context of simulation of flow and transport in a heterogeneous porous medium. More precisely, we consider the stratified likelihood (SL) sampling method of [3], in which attribute realizations are generated using the polar simulation method by exploring the geometrical properties of the multivariate Gaussian distribution function. In addition, we propose a more efficient version of the above method, here termed minimum energy (ME) sampling, whereby a set of N representative conductivity realizations at M locations is constructed by: (i) generating a representative set of N points distributed on the surface of a M-dimensional, unit radius hyper-sphere, (ii) relocating the N points on a representative set of N hyper-spheres of different radii, and (iii) transforming the coordinates of those points to lie on N different hyper-ellipsoids spanning the multivariate Gaussian distribution. The above method is applied in a dimensionality reduction context by defining flow-controlling points over which representative sampling of hydraulic conductivity is performed, thus also accounting for the sensitivity of the flow and transport model to the input hydraulic conductivity field. The performance of the various stratified sampling methods, LH, SL, and ME, is compared to that of SR sampling in terms of reproduction of ensemble statistics of hydraulic conductivity and solute concentration for different sample sizes N (numbers of realizations). The results indicate that ME sampling constitutes an equally if not more efficient simulation method than LH and SL sampling, as it can reproduce to a similar extent statistics of the conductivity and concentration fields, yet with smaller sampling variability than SR sampling. References [1] Gutjahr A.L. and Bras R.L. Spatial variability in subsurface flow and transport: A review. Reliability Engineering & System Safety, 42, 293-316, (1993). [2] Helton J.C. and Davis F.J. Latin hypercube sampling and the propagation of uncertainty in analyses of complex systems. Reliability Engineering & System Safety, 81, 23-69, (2003). [3] Switzer P. Multiple simulation of spatial fields. In: Heuvelink G, Lemmens M (eds) Proceedings of the 4th International Symposium on Spatial Accuracy Assessment in Natural Resources and Environmental Sciences, Coronet Books Inc., pp 629?635 (2000).

Should Security Researchers Experiment More and Draw More Inferences?

DTIC Science & Technology

2011-08-01

knowledge would be enormous. To obtain a large and representative sample of keystroke-dynamics research papers, we consulted the IEEE Xplore database... IEEE Xplore are similar to those published elsewhere), these confidence intervals estimate the re- gions where those true percentages would lie with 95...of articles and conference pro- ceedings published by the IEEE , to which our university maintains a subscription. We conducted two keyword searches for

The database of the PREDICTS (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems) project

Treesearch

Lawrence N. Hudson; Joseph Wunderle M.; And Others

2016-01-01

The PREDICTS project—Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)—has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used this evidence base to...

Psychosocial Outcomes Related to Subjective Threat from Armed Conflict Events (STACE): Findings from the Israeli-Palestinian Cross-Cultural HBSC Study

ERIC Educational Resources Information Center

Harel-Fisch, Yossi; Radwan, Qasrowi; Walsh, Sophie D.; Laufer, Avital; Amitai, Gabriel; Fogel-Grinvald, Haya; Abdeen, Ziad

2010-01-01

Objective: This study investigates the relationship between exposure to armed conflict and terror events, and an array of mental and behavioral outcomes within a large cross-cultural scientifically representative sample of 24,935 Palestinian (7,430 West Bank and 7,217 Gaza) and Israeli (5,255 Jewish and 6,033 Arab) 11-, 13-, and 15-year-old school…

Greenstone belts: Their boundaries, surrounding rock terrains and interrelationships

NASA Technical Reports Server (NTRS)

Percival, J. A.; Card, K. D.

1986-01-01

Greenstone belts are an important part of the fragmented record of crustal evolution, representing samples of the magmatic activity that formed much of the Earth's crust. Most belts developed rapidly, in less than 100 Ma, leaving large gaps in the geological record. Surrounding terrains provide information on the context of greenstone belts. The effects of tectonic setting, structural geometry and evolution, associated plutonic activity and sedimentation are discussed.

Big River Benthos: Linking Year Round Biological Response to Altered Hydrological Regimes

DTIC Science & Technology

2017-04-02

is also home to a diversity of organisms adapted to large river habitats. Macroinvertebrates have long been used as habitat/water quality indicators...substrates, but lower abundances (Figure 5). Sand was the most frequently encountered substrate (n=52, Figure 6), and comprises approximately 80% of the...June sampling represented as percentages. 8 Because sand is predominant in the LMR, habitats containing a variety of substrates, including silt

Mediating Pathways in the Socio-Economic Gradient of Child Development: Evidence from Children 6-42 Months in Bogota

ERIC Educational Resources Information Center

Rubio-Codina, Marta; Attanasio, Orazio; Grantham-McGregor, Sally

2016-01-01

Research has previously shown a gap of near 0.5 of a standard deviation (SD) in cognition and language development between the top and bottom household wealth quartile in children aged 6-42 months in a large representative sample of low- and middle-income families in Bogota, using the Bayley Scales of Infant and Toddler Development. The gaps in…

The susceptibility of large river basins to orogenic and climatic drivers

NASA Astrophysics Data System (ADS)

Haedke, Hanna; Wittmann, Hella; von Blanckenburg, Friedhelm

2017-04-01

Large rivers are known to buffer pulses in sediment production driven by changes in climate as sediment is transported through lowlands. Our new dataset of in situ cosmogenic nuclide concentration and chemical composition of 62 sandy bedload samples from the world largest rivers integrates over 25% of Earth's terrestrial surface, distributed over a variety of climatic zones across all continents, and represents the millennial-scale denudation rate of the sediment's source area. We can show that these denudation rates do not respond to climatic forcing, but faithfully record orogenic forcing, when analyzed with respective variables representing orogeny (strain rate, relief, bouguer anomaly, free-air anomaly), and climate (runoff, temperature, precipitation) and basin properties (floodplain response time, drainage area). In contrast to this orogenic forcing of denudation rates, elemental bedload chemistry from the fine-grained portion of the same samples correlates with climate-related variables (precipitation, runoff) and floodplain response times. It is also well-known from previous compilations of river-gauged sediment loads that the short-term basin-integrated sediment export is also climatically controlled. The chemical composition of detrital sediment shows a climate control that can originate in the rivers source area, but this signal is likely overprinted during transfer through the lowlands because we also find correlation with floodplain response times. At the same time, cosmogenic nuclides robustly preserve the orogenic forcing of the source area denudation signal through of the floodplain buffer. Conversely, previous global compilations of cosmogenic nuclides in small river basins show the preservation of climate drivers in their analysis, but these are buffered in large lowland rivers. Hence, we can confirm the assumption that cosmogenic nuclides in large rivers are poorly susceptible to climate changes, but are at the same time highly suited to detect changes in orogenic forcing in their paleo sedimentary records.

Decomposition and model selection for large contingency tables.

PubMed

Dahinden, Corinne; Kalisch, Markus; Bühlmann, Peter

2010-04-01

Large contingency tables summarizing categorical variables arise in many areas. One example is in biology, where large numbers of biomarkers are cross-tabulated according to their discrete expression level. Interactions of the variables are of great interest and are generally studied with log-linear models. The structure of a log-linear model can be visually represented by a graph from which the conditional independence structure can then be easily read off. However, since the number of parameters in a saturated model grows exponentially in the number of variables, this generally comes with a heavy computational burden. Even if we restrict ourselves to models of lower-order interactions or other sparse structures, we are faced with the problem of a large number of cells which play the role of sample size. This is in sharp contrast to high-dimensional regression or classification procedures because, in addition to a high-dimensional parameter, we also have to deal with the analogue of a huge sample size. Furthermore, high-dimensional tables naturally feature a large number of sampling zeros which often leads to the nonexistence of the maximum likelihood estimate. We therefore present a decomposition approach, where we first divide the problem into several lower-dimensional problems and then combine these to form a global solution. Our methodology is computationally feasible for log-linear interaction models with many categorical variables each or some of them having many levels. We demonstrate the proposed method on simulated data and apply it to a bio-medical problem in cancer research.

A follow-up study of hygiene in catering premises at large-scale events in the United Kingdom.

PubMed

Willis, C; Elviss, N; McLauchlin, J

2015-01-01

To investigate food hygiene practices at large events by assessing the microbiological quality of ready-to-eat food, drinking water, food preparation surfaces, cleaning cloths and wristbands worn by food handlers for event security purposes. Over a 7-month period, 1662 samples were collected at 153 events and examined for microbiological contamination. Eight per cent of food samples were of an unsatisfactory quality. A further one per cent contained potentially hazardous levels of human pathogenic bacteria. 27% of water samples, 32% of swabs and 56% of cloths were also unsatisfactory. These results represented an improvement in hygiene compared to a previous study carried out 12 months previously. A fifth of food handler wristbands were contaminated with Enterobacteriaceae, Escherichia coli and/or coagulase-positive staphylococci, with those bands made from fabric being more frequently contaminated than those made from plastic or other materials. This study provides evidence that the food hygiene at large-scale events may have improved. However, there is still a need for continued efforts to maintain an ongoing improvement in cleaning regimes and food hygiene management. This study was part of an ongoing focus on large events in the lead-up to the London 2012 Olympics. Lessons learnt here will be important in the planning of future large events. © 2014 Crown copyright. © 2014 Society for Applied Microbiology This article is Published with the permission of the Controller of HMSO and Queen's Printer for Scotland.

Testing the Paradigm that Ultra-Luminous X-Ray Sources as a Class Represent Accreting Intermediate

NASA Technical Reports Server (NTRS)

Berghea, C. T.; Weaver, K. A.; Colbert, E. J. M.; Roberts, T. P.

2008-01-01

To test the idea that ultraluminous X-ray sources (ULXs) in external galaxies represent a class of accreting Intermediate-Mass Black Holes (IMBHs), we have undertaken a program to identify ULXs and a lower luminosity X-ray comparison sample with the highest quality data in the Chandra archive. We establish a general property of ULXs that the most X-ray luminous objects possess the fattest X-ray spectra (in the Chandra band pass). No prior sample studies have established the general hardening of ULX spectra with luminosity. This hardening occurs at the highest luminosities (absorbed luminosity > or equals 5x10(exp 39) ergs/s) and is in line with recent models arguing that ULXs are actually stellar-mass black holes. From spectral modeling, we show that the evidence originally taken to mean that ULXs are IMBHs - i.e., the "simple IMBH model" - is nowhere near as compelling when a large sample of ULXs is looked at properly. During the last couple of years, XMM-Newton spectroscopy of ULXs has to some large extent begun to negate the simple IMBH model based on fewer objects. We confirm and expand these results, which validates the XMM-Newton work in a broader sense with independent X-ray data. We find (1) that cool disk components are present with roughly equal probability and total flux fraction for any given ULX, regardless of luminosity, and (2) that cool disk components extend below the standard ULX luminosity cutoff of 10(exp 39) ergs/s, down to our sample limit of 10(exp 38:3) ergs/s. The fact that cool disk components are not correlated with luminosity damages the argument that cool disks indicate IMBHs in ULXs, for which a strong statistical support was never made.

Testing the Paradigm that Ultraluminous X-Ray Sources as a Class Represent Accreting Intermediate-Mass Black Holes

NASA Astrophysics Data System (ADS)

Berghea, C. T.; Weaver, K. A.; Colbert, E. J. M.; Roberts, T. P.

2008-11-01

To test the idea that ultraluminous X-ray sources (ULXs) in external galaxies represent a class of accreting intermediate-mass black holes (IMBHs), we have undertaken a program to identify ULXs and a lower luminosity X-ray comparison sample with the highest quality data in the Chandra archive. We establish as a general property of ULXs that the most X-ray-luminous objects possess the flattest X-ray spectra (in the Chandra bandpass). No prior sample studies have established the general hardening of ULX spectra with luminosity. This hardening occurs at the highest luminosities (absorbed luminosity >=5 × 1039 erg s-1) and is in line with recent models arguing that ULXs are actually stellar mass black holes. From spectral modeling, we show that the evidence originally taken to mean that ULXs are IMBHs—i.e., the "simple IMBH model"—is nowhere near as compelling when a large sample of ULXs is looked at properly. During the last couple of years, XMM-Newton spectroscopy of ULXs has to a large extent begun to negate the simple IMBH model based on fewer objects. We confirm and expand these results, which validates the XMM-Newton work in a broader sense with independent X-ray data. We find that (1) cool-disk components are present with roughly equal probability and total flux fraction for any given ULX, regardless of luminosity, and (2) cool-disk components extend below the standard ULX luminosity cutoff of 1039 erg s-1, down to our sample limit of 1038.3 erg s-1. The fact that cool-disk components are not correlated with luminosity damages the argument that cool disks indicate IMBHs in ULXs, for which strong statistical support was never found.

21 CFR 111.80 - What representative samples must you collect?

Code of Federal Regulations, 2010 CFR

2010-04-01

... Process Control System § 111.80 What representative samples must you collect? The representative samples... unique lot within each unique shipment); (b) Representative samples of in-process materials for each manufactured batch at points, steps, or stages, in the manufacturing process as specified in the master...

Negative symptoms in schizophrenia: a study in a large clinical sample of patients using a novel automated method.

PubMed

Patel, Rashmi; Jayatilleke, Nishamali; Broadbent, Matthew; Chang, Chin-Kuo; Foskett, Nadia; Gorrell, Genevieve; Hayes, Richard D; Jackson, Richard; Johnston, Caroline; Shetty, Hitesh; Roberts, Angus; McGuire, Philip; Stewart, Robert

2015-09-07

To identify negative symptoms in the clinical records of a large sample of patients with schizophrenia using natural language processing and assess their relationship with clinical outcomes. Observational study using an anonymised electronic health record case register. South London and Maudsley NHS Trust (SLaM), a large provider of inpatient and community mental healthcare in the UK. 7678 patients with schizophrenia receiving care during 2011. Hospital admission, readmission and duration of admission. 10 different negative symptoms were ascertained with precision statistics above 0.80. 41% of patients had 2 or more negative symptoms. Negative symptoms were associated with younger age, male gender and single marital status, and with increased likelihood of hospital admission (OR 1.24, 95% CI 1.10 to 1.39), longer duration of admission (β-coefficient 20.5 days, 7.6-33.5), and increased likelihood of readmission following discharge (OR 1.58, 1.28 to 1.95). Negative symptoms were common and associated with adverse clinical outcomes, consistent with evidence that these symptoms account for much of the disability associated with schizophrenia. Natural language processing provides a means of conducting research in large representative samples of patients, using data recorded during routine clinical practice. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Successful application of FTA Classic Card technology and use of bacteriophage phi29 DNA polymerase for large-scale field sampling and cloning of complete maize streak virus genomes.

PubMed

Owor, Betty E; Shepherd, Dionne N; Taylor, Nigel J; Edema, Richard; Monjane, Adérito L; Thomson, Jennifer A; Martin, Darren P; Varsani, Arvind

2007-03-01

Leaf samples from 155 maize streak virus (MSV)-infected maize plants were collected from 155 farmers' fields in 23 districts in Uganda in May/June 2005 by leaf-pressing infected samples onto FTA Classic Cards. Viral DNA was successfully extracted from cards stored at room temperature for 9 months. The diversity of 127 MSV isolates was analysed by PCR-generated RFLPs. Six representative isolates having different RFLP patterns and causing either severe, moderate or mild disease symptoms, were chosen for amplification from FTA cards by bacteriophage phi29 DNA polymerase using the TempliPhi system. Full-length genomes were inserted into a cloning vector using a unique restriction enzyme site, and sequenced. The 1.3-kb PCR product amplified directly from FTA-eluted DNA and used for RFLP analysis was also cloned and sequenced. Comparison of cloned whole genome sequences with those of the original PCR products indicated that the correct virus genome had been cloned and that no errors were introduced by the phi29 polymerase. This is the first successful large-scale application of FTA card technology to the field, and illustrates the ease with which large numbers of infected samples can be collected and stored for downstream molecular applications such as diversity analysis and cloning of potentially new virus genomes.

Spatial and Temporal Variations in Diatoms from la Chaine des Lacs Urban Watershed, Nord-Pas France, in Relation to Water Quality

NASA Astrophysics Data System (ADS)

Noble, P. J.; Van de Vijver, B.; Verleyen, E.; Prygiel, J.; Ivanovsky, A.; Lesven, L.; Billon, G.

2016-12-01

Diatom analysis was conducted on lake sediments in la Chaîne des Lacs (CDL), a shallow eutrophic urban park and storm control system in Villeneuve d'Ascq, France, to address both the present day water quality, and the evolution of this urban system over its 40 year history. The main lake, Lac du Héron (LDH), received recent attention because of water quality problems, including eutrophication, harmful algal blooms, and invasion by the macrophyte Elodea in 2012. A total of 17 sites were collected in CDL, 11 of which were in LDH, to document spatial variability, and a 26cm long core addresses historical changes. The bulk of the diatom assemblage in LDH can be classified as both eutrophic and moderately metal tolerant, using modern national diatom indices developed and used by the French regional water agencies. Surface sediment samples within LDH show large spatial variations in %Cocconeis placentula whose habitat is epiphytic growth on Elodea. Other variation is reflected in the phytoplankton composition both spatially, and interannually. Aulacoseira muzzanensis and Cyclostephanos dubius showed greater abundance in the open water habitats in LDH, whereas sites in CDL outside of LDH had greater Cyclotella meneghiniana. Temporally, Stephanodicsus (largely S. hantzschii), the dominant diatom in early spring, were present in greater abundances in the 2016 surface sediment samples than in any of the 2015 samples. One possible explanation is that the 2016 samples, taken March 30th, preferentially preserved the early spring Stephanodiscus bloom, in contrast to the 2015 samples, which were taken in January. The sediment core provides an historical record, where the uppermost 4cm plot with the bulk of the LDH surface samples and contain abundant Cocconeis, 4 -14cm is phytoplankton-rich, largely Cyclostephanos dubius and Aulacoseira muzzanensis, and represents a less weed-choked environment prior to the 2012 Elodea invasion. The base of the core is dominated by Amphora and Rhoicosphenia abbreviata, is most similar to an outlier site on the Marque River, and represents early conditions after the reservoir was established. Continued work will focus on relating these results to urban development, improvements of the sewage system, and meteorological patterns.

Nationwide Databases in Orthopaedic Surgery Research.

PubMed

Bohl, Daniel D; Singh, Kern; Grauer, Jonathan N

2016-10-01

The use of nationwide databases to conduct orthopaedic research has expanded markedly in recent years. Nationwide databases offer large sample sizes, sampling of patients who are representative of the country as a whole, and data that enable investigation of trends over time. The most common use of nationwide databases is to study the occurrence of postoperative adverse events. Other uses include the analysis of costs and the investigation of critical hospital metrics, such as length of stay and readmission rates. Although nationwide databases are powerful research tools, readers should be aware of the differences between them and their limitations. These include variations and potential inaccuracies in data collection, imperfections in patient sampling, insufficient postoperative follow-up, and lack of orthopaedic-specific outcomes.

The Earth Microbiome Project and Global Systems Biology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gilbert, Jack A.; Jansson, Janet K.; Knight, Rob

Recently, we published the first large-scale analysis of data from the Earth Microbiome Project (1, 2), a truly multidisciplinary research program involving more than 500 scientists and 27,751 samples acquired from 43 countries. These samples represent myriad specimen types and span a wide range of biotic and abiotic factors, geographic locations, and physicochemical properties. The database (https://qiita.ucsd.edu/emp/) is still growing, with over 90,000 amplicon datasets, >500 metagenomic runs, and metabolomics datasets from a similar number of samples. Importantly, the techniques, data and analytical tools are all standardized and publicly accessible, providing a framework to support research at a scale ofmore » integration that just 7 years ago seemed impossible.« less

Relation of average and highest solvent vapor concentrations in workplaces in small to medium enterprises and large enterprises.

PubMed

Ukai, Hirohiko; Ohashi, Fumiko; Samoto, Hajime; Fukui, Yoshinari; Okamoto, Satoru; Moriguchi, Jiro; Ezaki, Takafumi; Takada, Shiro; Ikeda, Masayuki

2006-04-01

The present study was initiated to examine the relationship between the workplace concentrations and the estimated highest concentrations in solvent workplaces (SWPs), with special references to enterprise size and types of solvent work. Results of survey conducted in 1010 SWPs in 156 enterprises were taken as a database. Workplace air was sampled at > or = 5 crosses in each SWP following a grid sampling strategy. An additional air was grab-sampled at the site where the worker's exposure was estimated to be highest (estimated highest concentration or EHC). The samples were analyzed for 47 solvents designated by regulation, and solvent concentrations in each sample were summed up by use of additiveness formula. From the workplace concentrations at > or = 5 points, geometric mean and geometric standard deviations were calculated as the representative workplace concentration (RWC) and the indicator of variation in workplace concentration (VWC). Comparison between RWC and EHC in the total of 1010 SWPs showed that EHC was 1.2 (in large enterprises with>300 employees) to 1.7 times [in small to medium (SM) enterprises with < or = 300 employees] greater than RWC. When SWPs were classified into SM enterprises and large enterprises, both RWC and EHC were significantly higher in SM enterprises than in large enterprises. Further comparison by types of solvent work showed that the difference was more marked in printing, surface coating and degreasing/cleaning/wiping SWPs, whereas it was less remarkable in painting SWPs and essentially nil in testing/research laboratories. In conclusion, the present observation as discussed in reference to previous publications suggests that RWC, EHC and the ratio of EHC/WRC varies substantially among different types of solvent work as well as enterprise size, and are typically higher in printing SWPs in SM enterprises.

Insomnia Associated with Valerian and Melatonin Usage in the 2002 National Health Interview Survey

PubMed Central

Bliwise, Donald L.; Ansari, Farzaneh Pour

2007-01-01

Study Objective: Many people use dietary supplements or herbal products to help them sleep. We analyzed the associations between melatonin use and insomnia and between valerian use and insomnia in a representative sample of the United States population. Design and Participants: The data reported upon here were collected in the 2002 Alternative Health/Complementary and Alternative Medicine (CAM) Supplement to the National Health Interview Survey. This was a survey of 31,044 personal interviews that constituted an age-representative and socioeconomically representative sample of the civilian noninstitutionalized population of the United States. Results: Of the survey sample, 5.9% used valerian and 5.2% used melatonin. Of those using valerian, 29.9% endorsed insomnia as 1 reason for CAM use, and, of melatonin users, 27.5% endorsed insomnia as 1 reason for CAM use. Relatively greater use occurred in individuals under age 60 years. The decision to use such substances was made in consultation with a health care provider less than half of the time. Conclusions: Large segments of the United States population used valerian or melatonin for insomnia within the year preceding the survey, and usage typically fell outside the purview of the health care system. Citation: Bliwise DL; Ansari FP. Insomnia associated with valerian and melatonin usage in the 2002 National Health Interview Survey. SLEEP 2007;30(7):881-884. PMID:17682659

From K giants to G dwarfs: stellar lifetime effects on metallicity distributions derived from red giants

NASA Astrophysics Data System (ADS)

Manning, Ellen M.; Cole, Andrew A.

2017-11-01

We examine the biases inherent to chemical abundance distributions when targets are selected from the red giant branch (RGB), using simulated giant branches created from isochrones. We find that even when stars are chosen from the entire colour range of RGB stars and over a broad range of magnitudes, the relative numbers of stars of different ages and metallicities, integrated over all stellar types, are not accurately represented in the giant branch sample. The result is that metallicity distribution functions derived from RGB star samples require a correction before they can be fitted by chemical evolution models. We derive simple correction factors for over- and under-represented populations for the limiting cases of single-age populations with a broad range of metallicities and of continuous star formation at constant metallicity; an important general conclusion is that intermediate-age populations (≈1-4 Gyr) are over-represented in RGB samples. We apply our models to the case of the Large Magellanic Cloud bar and show that the observed metallicity distribution underestimates the true number of metal-poor stars by more than 25 per cent; as a result, the inferred importance of gas flows in chemical evolution models could potentially be overestimated. The age- and metallicity-dependences of RGB lifetimes require careful modelling if they are not to lead to spurious conclusions about the chemical enrichment history of galaxies.

A machine learning model with human cognitive biases capable of learning from small and biased datasets.

PubMed

Taniguchi, Hidetaka; Sato, Hiroshi; Shirakawa, Tomohiro

2018-05-09

Human learners can generalize a new concept from a small number of samples. In contrast, conventional machine learning methods require large amounts of data to address the same types of problems. Humans have cognitive biases that promote fast learning. Here, we developed a method to reduce the gap between human beings and machines in this type of inference by utilizing cognitive biases. We implemented a human cognitive model into machine learning algorithms and compared their performance with the currently most popular methods, naïve Bayes, support vector machine, neural networks, logistic regression and random forests. We focused on the task of spam classification, which has been studied for a long time in the field of machine learning and often requires a large amount of data to obtain high accuracy. Our models achieved superior performance with small and biased samples in comparison with other representative machine learning methods.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Polacci, M.; Baker, D.R.; Bai, L.

Volcanic degassing is directly linked to magma dynamics and controls the style of eruptive activity. To better understand how gas is transported within basaltic magma we perform a 3D investigation of vesicles preserved in scoria from the 2005 activity at Stromboli volcano (Italy). We find that clasts are characterized by the ubiquitous occurrence of one to a few large vesicles, exhibiting mostly irregular, tortuous, channel-like textures, orders of magnitude greater in volume than all the other vesicles in the sample. We compare observations on natural samples with results from numerical simulations and experimental investigations of vesicle size distributions and demonstratemore » that this type of vesicle invariably forms in magmas with vesicularities > 0.30 (and possibly > 0.10). We suggest that large vesicles represent pathways used by gas to flow non-explosively to the surface and that they indicate the development of an efficient system that sustains persistent degassing in basaltic systems.« less

Random sampling of elementary flux modes in large-scale metabolic networks.

PubMed

Machado, Daniel; Soons, Zita; Patil, Kiran Raosaheb; Ferreira, Eugénio C; Rocha, Isabel

2012-09-15

The description of a metabolic network in terms of elementary (flux) modes (EMs) provides an important framework for metabolic pathway analysis. However, their application to large networks has been hampered by the combinatorial explosion in the number of modes. In this work, we develop a method for generating random samples of EMs without computing the whole set. Our algorithm is an adaptation of the canonical basis approach, where we add an additional filtering step which, at each iteration, selects a random subset of the new combinations of modes. In order to obtain an unbiased sample, all candidates are assigned the same probability of getting selected. This approach avoids the exponential growth of the number of modes during computation, thus generating a random sample of the complete set of EMs within reasonable time. We generated samples of different sizes for a metabolic network of Escherichia coli, and observed that they preserve several properties of the full EM set. It is also shown that EM sampling can be used for rational strain design. A well distributed sample, that is representative of the complete set of EMs, should be suitable to most EM-based methods for analysis and optimization of metabolic networks. Source code for a cross-platform implementation in Python is freely available at http://code.google.com/p/emsampler. dmachado@deb.uminho.pt Supplementary data are available at Bioinformatics online.

Fast Ordered Sampling of DNA Sequence Variants.

PubMed

Greenberg, Anthony J

2018-05-04

Explosive growth in the amount of genomic data is matched by increasing power of consumer-grade computers. Even applications that require powerful servers can be quickly tested on desktop or laptop machines if we can generate representative samples from large data sets. I describe a fast and memory-efficient implementation of an on-line sampling method developed for tape drives 30 years ago. Focusing on genotype files, I test the performance of this technique on modern solid-state and spinning hard drives, and show that it performs well compared to a simple sampling scheme. I illustrate its utility by developing a method to quickly estimate genome-wide patterns of linkage disequilibrium (LD) decay with distance. I provide open-source software that samples loci from several variant format files, a separate program that performs LD decay estimates, and a C++ library that lets developers incorporate these methods into their own projects. Copyright © 2018 Greenberg.

A comparison of the male customers of female street prostitutes with national samples of men.

PubMed

Monto, Martin A; McRee, Nick

2005-10-01

Previous research on customers of prostitutes has relied on small samples and qualitative interviews. Conceptions of customers have tended toward either the "every man" perspective, which implies customers are no different than other men, or the "peculiar man" perspective, which implies customers are characterized by stark differences or psychological inadequacies. This study compares a large sample of men (N = 1672) arrested for trying to hire street prostitutes with nationally representative samples of men. Customers were less likely to be married, less likely to be happily married if married, and more likely to report being unhappy in general than men in the national samples. Customers also expressed greater sexual liberalism and reported thinking about sex, masturbating, and participating in other aspects of the sex industry more frequently than men in general. Most differences were small, indicating customers as a category differ from other men in degree rather than quality.

The use of laser-induced fluorescence or ultraviolet detectors for sensitive and selective analysis of tobramycin or erythropoietin in complex samples.

PubMed

Ahmed, Hytham M; Ebeid, Wael B

2015-05-15

Complex samples analysis is a challenge in pharmaceutical and biopharmaceutical analysis. In this work, tobramycin (TOB) analysis in human urine samples and recombinant human erythropoietin (rhEPO) analysis in the presence of similar protein were selected as representative examples of such samples analysis. Assays of TOB in urine samples are difficult because of poor detectability. Therefore laser induced fluorescence detector (LIF) was combined with a separation technique, micellar electrokinetic chromatography (MEKC), to determine TOB through derivatization with fluorescein isothiocyanate (FITC). Borate was used as background electrolyte (BGE) with negative-charged mixed micelles as additive. The method was successively applied to urine samples. The LOD and LOQ for Tobramycin in urine were 90 and 200ng/ml respectively and recovery was >98% (n=5). All urine samples were analyzed by direct injection without sample pre-treatment. Another use of hyphenated analytical technique, capillary zone electrophoresis (CZE) connected to ultraviolet (UV) detector was also used for sensitive analysis of rhEPO at low levels (2000IU) in the presence of large amount of human serum albumin (HSA). Analysis of rhEPO was achieved by the use of the electrokinetic injection (EI) with discontinuous buffers. Phosphate buffer was used as BGE with metal ions as additive. The proposed method can be used for the estimation of large number of quality control rhEPO samples in a short period. Copyright © 2015 Elsevier B.V. All rights reserved.

Improved Estimation and Interpretation of Correlations in Neural Circuits

PubMed Central

Yatsenko, Dimitri; Josić, Krešimir; Ecker, Alexander S.; Froudarakis, Emmanouil; Cotton, R. James; Tolias, Andreas S.

2015-01-01

Ambitious projects aim to record the activity of ever larger and denser neuronal populations in vivo. Correlations in neural activity measured in such recordings can reveal important aspects of neural circuit organization. However, estimating and interpreting large correlation matrices is statistically challenging. Estimation can be improved by regularization, i.e. by imposing a structure on the estimate. The amount of improvement depends on how closely the assumed structure represents dependencies in the data. Therefore, the selection of the most efficient correlation matrix estimator for a given neural circuit must be determined empirically. Importantly, the identity and structure of the most efficient estimator informs about the types of dominant dependencies governing the system. We sought statistically efficient estimators of neural correlation matrices in recordings from large, dense groups of cortical neurons. Using fast 3D random-access laser scanning microscopy of calcium signals, we recorded the activity of nearly every neuron in volumes 200 μm wide and 100 μm deep (150–350 cells) in mouse visual cortex. We hypothesized that in these densely sampled recordings, the correlation matrix should be best modeled as the combination of a sparse graph of pairwise partial correlations representing local interactions and a low-rank component representing common fluctuations and external inputs. Indeed, in cross-validation tests, the covariance matrix estimator with this structure consistently outperformed other regularized estimators. The sparse component of the estimate defined a graph of interactions. These interactions reflected the physical distances and orientation tuning properties of cells: The density of positive ‘excitatory’ interactions decreased rapidly with geometric distances and with differences in orientation preference whereas negative ‘inhibitory’ interactions were less selective. Because of its superior performance, this ‘sparse+latent’ estimator likely provides a more physiologically relevant representation of the functional connectivity in densely sampled recordings than the sample correlation matrix. PMID:25826696

Clustering analysis of proteins from microbial genomes at multiple levels of resolution.

PubMed

Zaslavsky, Leonid; Ciufo, Stacy; Fedorov, Boris; Tatusova, Tatiana

2016-08-31

Microbial genomes at the National Center for Biotechnology Information (NCBI) represent a large collection of more than 35,000 assemblies. There are several complexities associated with the data: a great variation in sampling density since human pathogens are densely sampled while other bacteria are less represented; different protein families occur in annotations with different frequencies; and the quality of genome annotation varies greatly. In order to extract useful information from these sophisticated data, the analysis needs to be performed at multiple levels of phylogenomic resolution and protein similarity, with an adequate sampling strategy. Protein clustering is used to construct meaningful and stable groups of similar proteins to be used for analysis and functional annotation. Our approach is to create protein clusters at three levels. First, tight clusters in groups of closely-related genomes (species-level clades) are constructed using a combined approach that takes into account both sequence similarity and genome context. Second, clustroids of conservative in-clade clusters are organized into seed global clusters. Finally, global protein clusters are built around the the seed clusters. We propose filtering strategies that allow limiting the protein set included in global clustering. The in-clade clustering procedure, subsequent selection of clustroids and organization into seed global clusters provides a robust representation and high rate of compression. Seed protein clusters are further extended by adding related proteins. Extended seed clusters include a significant part of the data and represent all major known cell machinery. The remaining part, coming from either non-conservative (unique) or rapidly evolving proteins, from rare genomes, or resulting from low-quality annotation, does not group together well. Processing these proteins requires significant computational resources and results in a large number of questionable clusters. The developed filtering strategies allow to identify and exclude such peripheral proteins limiting the protein dataset in global clustering. Overall, the proposed methodology allows the relevant data at different levels of details to be obtained and data redundancy eliminated while keeping biologically interesting variations.

Association between the prevalence of depression and age in a large representative German sample of people aged 53 to 80 years.

PubMed

Wild, Beate; Herzog, Wolfgang; Schellberg, Dieter; Lechner, Sabine; Niehoff, Doro; Brenner, Hermann; Rothenbacher, Dietrich; Stegmaier, Christa; Raum, Elke

2012-04-01

The aim of the study was to determine the association between the prevalence of clinically significant depression and age in a large representative sample of elderly German people. In the second follow-up (2005-2007) of the ESTHER cohort study, the 15-item geriatric depression scale (GDS-15) as well as a sociodemographic and clinical questionnaire were administered to a representative sample of 8270 people of ages 53 to 80 years. The prevalence of clinically significant depression was estimated using a GDS cut-off score of 5/6. Prevalence rates were estimated for the different age categories. Association between depression and age was analyzed using logistic regression, adjusted for gender, co-morbid medical disorders, education, marital status, physical activity, smoking, self-perceived cognitive impairment, and anti-depressive medication. Of the participants, 7878 (95.3%) completed more than twelve GDS items and were included in the study. The prevalence of clinically significant depression was 16.0% (95%CI = [15.2; 16.6]). The function of depression prevalence dependent on age group showed a U-shaped pattern (53-59: 21.0%, CI = [18.9; 23.3]; 60-64: 17.7%, CI = [15.7; 19.7]; 65-69: 12.6%, CI = [11.2; 14.0]; 70-74: 14.4%, CI = [12.6; 16.0]; 75-80: 17.1%, CI = [14.9; 19.4]). Adjusted odds ratios showed that the chances of being depressive decrease with the age category but remain relatively stable for people aged 65 and over. The prevalence of depression in the elderly seems to be associated with the age category. Adjusted odds ratios showed that people aged 60 and older had lower chances of being depressive than people aged 53 to 59 years. Copyright © 2011 John Wiley & Sons, Ltd.

Microbiome of the upper troposphere: Species composition and prevalence, effects of tropical storms, and atmospheric implications

PubMed Central

DeLeon-Rodriguez, Natasha; Lathem, Terry L.; Rodriguez-R, Luis M.; Barazesh, James M.; Anderson, Bruce E.; Beyersdorf, Andreas J.; Ziemba, Luke D.; Bergin, Michael; Nenes, Athanasios; Konstantinidis, Konstantinos T.

2013-01-01

The composition and prevalence of microorganisms in the middle-to-upper troposphere (8–15 km altitude) and their role in aerosol-cloud-precipitation interactions represent important, unresolved questions for biological and atmospheric science. In particular, airborne microorganisms above the oceans remain essentially uncharacterized, as most work to date is restricted to samples taken near the Earth’s surface. Here we report on the microbiome of low- and high-altitude air masses sampled onboard the National Aeronautics and Space Administration DC-8 platform during the 2010 Genesis and Rapid Intensification Processes campaign in the Caribbean Sea. The samples were collected in cloudy and cloud-free air masses before, during, and after two major tropical hurricanes, Earl and Karl. Quantitative PCR and microscopy revealed that viable bacterial cells represented on average around 20% of the total particles in the 0.25- to 1-μm diameter range and were at least an order of magnitude more abundant than fungal cells, suggesting that bacteria represent an important and underestimated fraction of micrometer-sized atmospheric aerosols. The samples from the two hurricanes were characterized by significantly different bacterial communities, revealing that hurricanes aerosolize a large amount of new cells. Nonetheless, 17 bacterial taxa, including taxa that are known to use C1–C4 carbon compounds present in the atmosphere, were found in all samples, indicating that these organisms possess traits that allow survival in the troposphere. The findings presented here suggest that the microbiome is a dynamic and underappreciated aspect of the upper troposphere with potentially important impacts on the hydrological cycle, clouds, and climate. PMID:23359712

Exploring Genomic Diversity Using Metagenomics of Deep-Sea Subsurface Microbes from the Louisville Seamount and the South Pacific Gyre

NASA Astrophysics Data System (ADS)

Tully, B. J.; Sylvan, J. B.; Heidelberg, J. F.; Huber, J. A.

2014-12-01

There are many limitations involved with sampling microbial diversity from deep-sea subsurface environments, ranging from physical sample collection, low microbial biomass, culturing at in situ conditions, and inefficient nucleic acid extractions. As such, we are continually modifying our methods to obtain better results and expanding what we know about microbes in these environments. Here we present analysis of metagenomes sequences from samples collected from 120 m within the Louisville Seamount and from the top 5-10cm of the sediment in the center of the south Pacific gyre (SPG). Both systems are low biomass with ~102 and ~104 cells per cm3 for Louisville Seamount samples analyzed and the SPG sediment, respectively. The Louisville Seamount represents the first in situ subseafloor basalt and the SPG sediments represent the first in situ low biomass sediment microbial metagenomes. Both of these environments, subseafloor basalt and sediments underlying oligotrophic ocean gyres, represent large provinces of the seafloor environment that remain understudied. Despite the low biomass and DNA generated from these samples, we have generated 16 near complete genomes (5 from Louisville and 11 from the SPG) from the two metagenomic datasets. These genomes are estimated to be between 51-100% complete and span a range of phylogenetic groups, including the Proteobacteria, Actinobacteria, Firmicutes, Chloroflexi, and unclassified bacterial groups. With these genomes, we have assessed potential functional capabilities of these organisms and performed a comparative analysis between the environmental genomes and previously sequenced relatives to determine possible adaptations that may elucidate survival mechanisms for these low energy environments. These methods illustrate a baseline analysis that can be applied to future metagenomic deep-sea subsurface datasets and will help to further our understanding of microbiology within these environments.

CloVR-ITS: Automated internal transcribed spacer amplicon sequence analysis pipeline for the characterization of fungal microbiota

PubMed Central

2013-01-01

Background Besides the development of comprehensive tools for high-throughput 16S ribosomal RNA amplicon sequence analysis, there exists a growing need for protocols emphasizing alternative phylogenetic markers such as those representing eukaryotic organisms. Results Here we introduce CloVR-ITS, an automated pipeline for comparative analysis of internal transcribed spacer (ITS) pyrosequences amplified from metagenomic DNA isolates and representing fungal species. This pipeline performs a variety of steps similar to those commonly used for 16S rRNA amplicon sequence analysis, including preprocessing for quality, chimera detection, clustering of sequences into operational taxonomic units (OTUs), taxonomic assignment (at class, order, family, genus, and species levels) and statistical analysis of sample groups of interest based on user-provided information. Using ITS amplicon pyrosequencing data from a previous human gastric fluid study, we demonstrate the utility of CloVR-ITS for fungal microbiota analysis and provide runtime and cost examples, including analysis of extremely large datasets on the cloud. We show that the largest fractions of reads from the stomach fluid samples were assigned to Dothideomycetes, Saccharomycetes, Agaricomycetes and Sordariomycetes but that all samples were dominated by sequences that could not be taxonomically classified. Representatives of the Candida genus were identified in all samples, most notably C. quercitrusa, while sequence reads assigned to the Aspergillus genus were only identified in a subset of samples. CloVR-ITS is made available as a pre-installed, automated, and portable software pipeline for cloud-friendly execution as part of the CloVR virtual machine package (http://clovr.org). Conclusion The CloVR-ITS pipeline provides fungal microbiota analysis that can be complementary to bacterial 16S rRNA and total metagenome sequence analysis allowing for more comprehensive studies of environmental and host-associated microbial communities. PMID:24451270

19 CFR 151.52 - Sampling procedures.

Code of Federal Regulations, 2012 CFR

2012-04-01

.... Representative commercial moisture and assay samples shall be taken under Customs supervision for testing by the Customs laboratory. The samples used for the moisture test shall be representative of the shipment at the... verified commercial moisture sample and prepared assay sample certified to be representative of the...

Questioning the stability of sense of coherence--the impact of socio-economic status and working conditions in the Canadian population.

PubMed

Smith, Peter M; Breslin, F Curtis; Beaton, Dorcas E

2003-09-01

Much debate exists about the stability of the sense of coherence measure. This study examined changes in sense of coherence (SOC), and the variables associated with these changes, over a 4-year period, in a representative sample of the Canadian labour force (n=6,790). Two methods were used to assess change in SOC: (1) Change outside of that which could be considered as indistinguishable from measurement error, and (2) Change of more than 10%, which was originally proposed by Antonovksy, the scales designer. Over the study period, 35.4% of the population reported changes in SOC outside the range we consider possible due to measurement error, with 58% reporting change greater than 10%. Unskilled occupations were associated with declines in SOC, with household income demonstrating a curvilinear relationship with decline in SOC in the female population only. None of the variables used predicted increases in SOC. Given the degree of change in SOC, and the representativeness of the study sample, we suggest that SOC has a large state component. Given this lack of stability, we recommend caution if using the SOC to represent a stable global orientation within a causal context.

Sampling of suspended particulate matter using particle traps in the Rhône River: Relevance and representativeness for the monitoring of contaminants.

PubMed

Masson, M; Angot, H; Le Bescond, C; Launay, M; Dabrin, A; Miège, C; Le Coz, J; Coquery, M

2018-05-10

Monitoring hydrophobic contaminants in surface freshwaters requires measuring contaminant concentrations in the particulate fraction (sediment or suspended particulate matter, SPM) of the water column. Particle traps (PTs) have been recently developed to sample SPM as cost-efficient, easy to operate and time-integrative tools. But the representativeness of SPM collected with PTs is not fully understood, notably in terms of grain size distribution and particulate organic carbon (POC) content, which could both skew particulate contaminant concentrations. The aim of this study was to evaluate the representativeness of SPM characteristics (i.e. grain size distribution and POC content) and associated contaminants (i.e. polychlorinated biphenyls, PCBs; mercury, Hg) in samples collected in a large river using PTs for differing hydrological conditions. Samples collected using PTs (n = 74) were compared with samples collected during the same time period by continuous flow centrifugation (CFC). The grain size distribution of PT samples shifted with increasing water discharge: the proportion of very fine silts (2-6 μm) decreased while that of coarse silts (27-74 μm) increased. Regardless of water discharge, POC contents were different likely due to integration by PT of high POC-content phytoplankton blooms or low POC-content flood events. Differences in PCBs and Hg concentrations were usually within the range of analytical uncertainties and could not be related to grain size or POC content shifts. Occasional Hg-enriched inputs may have led to higher Hg concentrations in a few PT samples (n = 4) which highlights the time-integrative capacity of the PTs. The differences of annual Hg and PCB fluxes calculated either from PT samples or CFC samples were generally below 20%. Despite some inherent limitations (e.g. grain size distribution bias), our findings suggest that PT sampling is a valuable technique to assess reliable spatial and temporal trends of particulate contaminants such as PCBs and Hg within a river monitoring network. Copyright © 2018 Elsevier B.V. All rights reserved.

Direct determination of the number-weighted mean radius and polydispersity from dynamic light-scattering data.

PubMed

Patty, Philipus J; Frisken, Barbara J

2006-04-01

We compare results for the number-weighted mean radius and polydispersity obtained either by directly fitting number distributions to dynamic light-scattering data or by converting results obtained by fitting intensity-weighted distributions. We find that results from fits using number distributions are angle independent and that converting intensity-weighted distributions is not always reliable, especially when the polydispersity of the sample is large. We compare the results of fitting symmetric and asymmetric distributions, as represented by Gaussian and Schulz distributions, respectively, to data for extruded vesicles and find that the Schulz distribution provides a better estimate of the size distribution for these samples.

Stellar Populations in Elliptical Galaxies

NASA Astrophysics Data System (ADS)

Angeletti, Lucio; Giannone, Pietro

The R1/n law for the radial surface brightness of elliptical galaxies and the "Best Accretion Model" together with the "Concentration Model" have been combined in order to determine the mass and dynamical structure of largely-populated star systems. Families of models depending on four parameters have been used to fit the observed surface radial profiles of some spectro-photometric indices of a sample of eleven galaxies. We present the best agreements of the spectral index Mg2 with observations for three selected galaxies representative of the full sample. For them we have also computed the spatial distributions of the metal abundances, which are essential to achieve a population synthesis.

Use of portable electronic devices in a hospital setting and their potential for bacterial colonization.

PubMed

Khan, Amber; Rao, Amitha; Reyes-Sacin, Carlos; Hayakawa, Kayoko; Szpunar, Susan; Riederer, Kathleen; Kaye, Keith; Fishbain, Joel T; Levine, Diane

2015-03-01

Portable electronic devices are increasingly being used in the hospital setting. As with other fomites, these devices represent a potential reservoir for the transmission of pathogens. We conducted a convenience sampling of devices in 2 large medical centers to identify bacterial colonization rates and potential risk factors. Copyright © 2015 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Skills of U.S. Unemployed, Young, and Older Adults in Sharper Focus: Results from the Program for the International Assessment of Adult Competencies (PIAAC) 2012/2014. First Look. NCES 2016-039

ERIC Educational Resources Information Center

Rampey, Bobby D.; Finnegan, Robert; Goodman, Madeline; Mohadjer, Leyla; Krenzke, Tom; Hogan, Jacquie; Provasnik, Stephen

2016-01-01

The "Program for the International Assessment of Adult Competencies" (PIAAC) is a cyclical, large-scale study of adult skills and life experiences focusing on education and employment. Nationally representative samples of adults between the ages of 16 and 65 are administered an assessment of literacy, numeracy, and problem solving in…

The functional spectrum of low-frequency coding variation.

PubMed

Marth, Gabor T; Yu, Fuli; Indap, Amit R; Garimella, Kiran; Gravel, Simon; Leong, Wen Fung; Tyler-Smith, Chris; Bainbridge, Matthew; Blackwell, Tom; Zheng-Bradley, Xiangqun; Chen, Yuan; Challis, Danny; Clarke, Laura; Ball, Edward V; Cibulskis, Kristian; Cooper, David N; Fulton, Bob; Hartl, Chris; Koboldt, Dan; Muzny, Donna; Smith, Richard; Sougnez, Carrie; Stewart, Chip; Ward, Alistair; Yu, Jin; Xue, Yali; Altshuler, David; Bustamante, Carlos D; Clark, Andrew G; Daly, Mark; DePristo, Mark; Flicek, Paul; Gabriel, Stacey; Mardis, Elaine; Palotie, Aarno; Gibbs, Richard

2011-09-14

Rare coding variants constitute an important class of human genetic variation, but are underrepresented in current databases that are based on small population samples. Recent studies show that variants altering amino acid sequence and protein function are enriched at low variant allele frequency, 2 to 5%, but because of insufficient sample size it is not clear if the same trend holds for rare variants below 1% allele frequency. The 1000 Genomes Exon Pilot Project has collected deep-coverage exon-capture data in roughly 1,000 human genes, for nearly 700 samples. Although medical whole-exome projects are currently afoot, this is still the deepest reported sampling of a large number of human genes with next-generation technologies. According to the goals of the 1000 Genomes Project, we created effective informatics pipelines to process and analyze the data, and discovered 12,758 exonic SNPs, 70% of them novel, and 74% below 1% allele frequency in the seven population samples we examined. Our analysis confirms that coding variants below 1% allele frequency show increased population-specificity and are enriched for functional variants. This study represents a large step toward detecting and interpreting low frequency coding variation, clearly lays out technical steps for effective analysis of DNA capture data, and articulates functional and population properties of this important class of genetic variation.

Metabarcoding analysis of strongylid nematode diversity in two sympatric primate species.

PubMed

Pafčo, Barbora; Čížková, Dagmar; Kreisinger, Jakub; Hasegawa, Hideo; Vallo, Peter; Shutt, Kathryn; Todd, Angelique; Petrželková, Klára J; Modrý, David

2018-04-12

Strongylid nematodes in large terrestrial herbivores such as great apes, equids, elephants, and humans tend to occur in complex communities. However, identification of all species within strongylid communities using traditional methods based on coproscopy or single nematode amplification and sequencing is virtually impossible. High-throughput sequencing (HTS) technologies provide opportunities to generate large amounts of sequence data and enable analyses of samples containing a mixture of DNA from multiple species/genotypes. We designed and tested an HTS approach for strain-level identification of gastrointestinal strongylids using ITS-2 metabarcoding at the MiSeq Illumina platform in samples from two free-ranging non-human primate species inhabiting the same environment, but differing significantly in their host traits and ecology. Although we observed overlapping of particular haplotypes, overall the studied primate species differed in their strongylid nematode community composition. Using HTS, we revealed hidden diversity in the strongylid nematode communities in non-human primates, more than one haplotype was found in more than 90% of samples and coinfections of more than one putative species occurred in 80% of samples. In conclusion, the HTS approach on strongylid nematodes, preferably using fecal samples, represents a time and cost-efficient way of studying strongylid communities and provides a resolution superior to traditional approaches.

Spatial versus Day-To-Day Within-Lake Variability in Tropical Floodplain Lake CH4 Emissions – Developing Optimized Approaches to Representative Flux Measurements

PubMed Central

Peixoto, Roberta B.; Machado-Silva, Fausto; Marotta, Humberto; Enrich-Prast, Alex; Bastviken, David

2015-01-01

Inland waters (lakes, rivers and reservoirs) are now understood to contribute large amounts of methane (CH4) to the atmosphere. However, fluxes are poorly constrained and there is a need for improved knowledge on spatiotemporal variability and on ways of optimizing sampling efforts to yield representative emission estimates for different types of aquatic ecosystems. Low-latitude floodplain lakes and wetlands are among the most high-emitting environments, and here we provide a detailed investigation of spatial and day-to-day variability in a shallow floodplain lake in the Pantanal in Brazil over a five-day period. CH4 flux was dominated by frequent and ubiquitous ebullition. A strong but predictable spatial variability (decreasing flux with increasing distance to the shore or to littoral vegetation) was found, and this pattern can be addressed by sampling along transects from the shore to the center. Although no distinct day-to-day variability were found, a significant increase in flux was identified from measurement day 1 to measurement day 5, which was likely attributable to a simultaneous increase in temperature. Our study demonstrates that representative emission assessments requires consideration of spatial variability, but also that spatial variability patterns are predictable for lakes of this type and may therefore be addressed through limited sampling efforts if designed properly (e.g., fewer chambers may be used if organized along transects). Such optimized assessments of spatial variability are beneficial by allowing more of the available sampling resources to focus on assessing temporal variability, thereby improving overall flux assessments. PMID:25860229

Gambling Type, Substance Abuse, Health and Psychosocial Correlates of Male and Female Problem Gamblers in a Nationally Representative French Sample.

PubMed

Bonnaire, C; Kovess-Masfety, V; Guignard, R; Richard, J B; du Roscoät, E; Beck, F

2017-06-01

Many studies carried out on treatment-seeking problem gamblers (PG) have reported high levels of comorbid substance use disorders, and mental and physical health problems. Nevertheless, general population studies are still sparse, most of them have been carried out in the United States or Canada, and gender differences have not always been considered. Thus, the aim of this study was to describe the type of games, and psychological and physical correlates in male and female PG in a nationally representative French sample. The total sample studied involved 25,647 subjects aged 15-85 years, including 333 PG and 25,314 non-problem gamblers (NPG). Data were extracted from a large survey of a representative sample of the French general population. They were evaluated for sociodemographic variables, gambling behavior, type of gambling activity, substance use, psychological distress, body mass index, chronic disease, and lack of sleep. Overall, there were significant differences between PG and NPG in gender, age, education, employment and marital status, substance use disorders (alcohol, tobacco, cannabis, cocaine and heroin), psychological distress, obesity, lack of sleep and type of gambling activity. Although male and female PG had different profiles, the gambling type, especially strategic games, appeared as an important variable in the relationship between gender and problem gambling. This research underlines the importance of considering gender differences and gambling type in the study of gambling disorders. Identifying specific factors in the relationship between gender, gambling type and gambling problems may help improve clinical interventions and health promotion strategies.

A semi-automated Raman micro-spectroscopy method for morphological and chemical characterizations of microplastic litter.

PubMed

L, Frère; I, Paul-Pont; J, Moreau; P, Soudant; C, Lambert; A, Huvet; E, Rinnert

2016-12-15

Every step of microplastic analysis (collection, extraction and characterization) is time-consuming, representing an obstacle to the implementation of large scale monitoring. This study proposes a semi-automated Raman micro-spectroscopy method coupled to static image analysis that allows the screening of a large quantity of microplastic in a time-effective way with minimal machine operator intervention. The method was validated using 103 particles collected at the sea surface spiked with 7 standard plastics: morphological and chemical characterization of particles was performed in <3h. The method was then applied to a larger environmental sample (n=962 particles). The identification rate was 75% and significantly decreased as a function of particle size. Microplastics represented 71% of the identified particles and significant size differences were observed: polystyrene was mainly found in the 2-5mm range (59%), polyethylene in the 1-2mm range (40%) and polypropylene in the 0.335-1mm range (42%). Copyright © 2016 Elsevier Ltd. All rights reserved.

House dust fungal communities' characterization: a double take on the six by sixty by six (6 × 60 × 6) project

NASA Astrophysics Data System (ADS)

Amaro, Raquel; Coelho, Sónia D.; Pastorinho, M. Ramiro; Taborda-Barata, Luís; Vaz-Patto, Maria A.; Monteiro, Marisa; Nepomuceno, Miguel C. S.; Lanzinha, Joăo C. G.; Teixeira, Joăo P.; Pereira, Cristiana C.; Sousa, Ana C. A.

2016-11-01

Fungi are a group of microbes that are found with particular incidence in the indoor environment. Their direct toxicity or capability of generating toxic compounds has been associated with a large number of adverse health effects, such as infectious diseases and allergies. Given that in modern society people spend a large part of their time indoors; fungal communities' characterization of this environmental compartment assumes paramount importance in the comprehension of health effects. House dust is an easy to obtain, time-integrative matrix, being its use in epidemiological studies on human exposure to environmental contaminants highly recommended. Furthermore, dust can carry a great variety of fungal content that undergoes a large number of processes that modulate and further complexify human exposure. Our study aims to identify and quantify the fungal community on house dust samples collected using two different methodologies (an approach not often seen in the literature): active (vacuum cleaner bags) and passive sampling (dust settled in petri dishes). Sampling was performed as part of the ongoing 6 × 60 × 6 Project in which six houses from Covilhă (Portugal), with building dates representative of six decades, were studied for a period of sixty days.

Efficient statistical tests to compare Youden index: accounting for contingency correlation.

PubMed

Chen, Fangyao; Xue, Yuqiang; Tan, Ming T; Chen, Pingyan

2015-04-30

Youden index is widely utilized in studies evaluating accuracy of diagnostic tests and performance of predictive, prognostic, or risk models. However, both one and two independent sample tests on Youden index have been derived ignoring the dependence (association) between sensitivity and specificity, resulting in potentially misleading findings. Besides, paired sample test on Youden index is currently unavailable. This article develops efficient statistical inference procedures for one sample, independent, and paired sample tests on Youden index by accounting for contingency correlation, namely associations between sensitivity and specificity and paired samples typically represented in contingency tables. For one and two independent sample tests, the variances are estimated by Delta method, and the statistical inference is based on the central limit theory, which are then verified by bootstrap estimates. For paired samples test, we show that the estimated covariance of the two sensitivities and specificities can be represented as a function of kappa statistic so the test can be readily carried out. We then show the remarkable accuracy of the estimated variance using a constrained optimization approach. Simulation is performed to evaluate the statistical properties of the derived tests. The proposed approaches yield more stable type I errors at the nominal level and substantially higher power (efficiency) than does the original Youden's approach. Therefore, the simple explicit large sample solution performs very well. Because we can readily implement the asymptotic and exact bootstrap computation with common software like R, the method is broadly applicable to the evaluation of diagnostic tests and model performance. Copyright © 2015 John Wiley & Sons, Ltd.

Petrologic constraints on the origin of the Moon: Evidence from Apollo 14

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shervais, J.W.; Taylor, L.A.

1984-01-01

The Fra Mauro breccias at Apollo 14 contain distinctive suites of mare basalts and highland crustal rocks that contrast significantly with equivalent rocks from other Apollo sites. These contrasts imply lateral heterogeneity of the lunar crust and mantle on a regional scale. This heterogeneity may date back to the earliest stages of lunar accretion and differentiation. Current theories requiring a Moon-wide crust of Ferroan Anorthosite are based largely on samples from Apollo 16, where all but a few samples represent the FAN suite. However, at the nearside sites, FAN is either scarce (A-15) or virtually absent (A-12, A-14, A-17). Itmore » is suggested that the compositional variations could be accounted for by the acceleration of a large mass of material (e.g., 0.1 to 0.2 moon masses) late in the crystallization history of the magma ocean. Besides adding fresh, primordial material, this would remelt a large pocket of crust and mantle, thereby allowing a second distillation to occur in the resulting magma sea.« less

Culture, management and finances as key aspects for healthy workplace initiatives.

PubMed

Waterworth, Pippa; Pescud, Melanie; Chappell, Stacie; Davies, Christina; Roche, Dee; Shilton, Trevor; Ledger, Melissa; Slevin, Terry; Rosenberg, Michael

2018-02-01

The aim of this study was to qualitatively explore the barriers and enablers to implementing healthy workplace initiatives in a sample of workplaces based in Perth, Western Australia. In-depth interviews were conducted with representatives from 31 organizations representing small, medium and large businesses in the Perth metropolitan area which reported having healthy workplace initiatives. In total, 43 factors were mentioned as influencing the implementation of healthy workplace initiatives. Factors appearing to exert the most influence on the implementation of health promoting initiatives in this sample were culture; support from managers and staff; collaboration with industry providers; financial resources circumstances and the physical environment. These factors appeared to be mutually reinforcing and interconnected. Findings suggest there may be merit in applying an organizational development lens to the implementation of workplace health promotion initiatives as this could assist in leveraging enablers and minimizing barriers. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Child sexual abuse as a risk factor for teen dating violence: Findings from a representative sample of Quebec youth

PubMed Central

Hébert, Martine; Moreau, Catherine; Blais, Martin; Lavoie, Francine; Guerrier, Mireille

2016-01-01

Child sexual abuse (CSA) is identified as a significant risk factor for later victimization in the context of adult intimate relationships, but less is known about the risk associated with CSA in early romantic relationships. This paper aims to document the association between CSA and teen dating victimization in a large representative sample of Quebec high-school students. As part of the Youths’ Romantic Relationships Project, 8,194 teens completed measures on CSA and psychological, physical and sexual dating violence. After controlling for other interpersonal traumas, results show that CSA contributed to all three forms of dating victimization among both boys and girls. The heightened risk of revictimization appears to be stronger for male victims of CSA. Intervention and prevention efforts are clearly needed to reduce the vulnerability of male and female victims of sexual abuse who are entering the crucial phase of adolescence and first romantic relationships. PMID:29308104

United States planetary rover status: 1989

NASA Technical Reports Server (NTRS)

Pivirotto, Donna L. S.; Dias, William C.

1990-01-01

A spectrum of concepts for planetary rovers and rover missions, is covered. Rovers studied range from tiny micro rovers to large and highly automated vehicles capable of traveling hundreds of kilometers and performing complex tasks. Rover concepts are addressed both for the Moon and Mars, including a Lunar/Mars common rover capable of supporting either program with relatively small modifications. Mission requirements considered include both Science and Human Exploration. Studies include a range of autonomy in rovers, from interactive teleoperated systems to those requiring and onboard System Executive making very high level decisions. Both high and low technology rover options are addressed. Subsystems are described for a representative selection of these rovers, including: Mobility, Sample Acquisition, Science, Vehicle Control, Thermal Control, Local Navigation, Computation and Communications. System descriptions of rover concepts include diagrams, technology levels, system characteristics, and performance measurement in terms of distance covered, samples collected, and area surveyed for specific representative missions. Rover development schedules and costs are addressed for Lunar and Mars exploration initiatives.

Spatial distribution of pollen grains and spores in surface sediments of Guanabara Bay, Rio de Janeiro, Brazil.

PubMed

Barreto, Cintia F; Vilela, Claudia G; Baptista-Neto, José A; Barth, Ortrud M

2012-09-01

Aiming to investigate the deposition of pollen grains and spores in Guanabara Bay, Rio de Janeiro State, 61 surface sediment samples were analyzed. The results showed that the current deposition of palynomorphs in surface sediments of Guanabara Bay represents the regional vegetation of this hydrographic basin. The differential distribution of palynomorphs followed a pattern influenced by bathymetry, tidal currents speed, discharge of numerous rivers, and by human activity. The dominance of representatives of Field Vegetation reflects the changes of the original flora caused by intense human activities in the region. The continued presence and richness of pollen types of rain forest in the samples indicates that their source area might be the vegetation from riparian border of rivers in the western sector of the Bay, where the mangrove vegetation is being preserved. The large amount of damaged palynomorphs may be related to abrasion that occurs during river transport, indicating removal or reworking from their areas of origin.

Comparison of water-quality samples collected by siphon samplers and automatic samplers in Wisconsin

USGS Publications Warehouse

Graczyk, David J.; Robertson, Dale M.; Rose, William J.; Steur, Jeffrey J.

2000-01-01

In small streams, flow and water-quality concentrations often change quickly in response to meteorological events. Hydrologists, field technicians, or locally hired stream ob- servers involved in water-data collection are often unable to reach streams quickly enough to observe or measure these rapid changes. Therefore, in hydrologic studies designed to describe changes in water quality, a combination of manual and automated sampling methods have commonly been used manual methods when flow is relatively stable and automated methods when flow is rapidly changing. Auto- mated sampling, which makes use of equipment programmed to collect samples in response to changes in stage and flow of a stream, has been shown to be an effective method of sampling to describe the rapid changes in water quality (Graczyk and others, 1993). Because of the high cost of automated sampling, however, especially for studies examining a large number of sites, alternative methods have been considered for collecting samples during rapidly changing stream conditions. One such method employs the siphon sampler (fig. 1). also referred to as the "single-stage sampler." Siphon samplers are inexpensive to build (about $25- $50 per sampler), operate, and maintain, so they are cost effective to use at a large number of sites. Their ability to collect samples representing the average quality of water passing though the entire cross section of a stream, however, has not been fully demonstrated for many types of stream sites.

MCDA swing weighting and discrete choice experiments for elicitation of patient benefit-risk preferences: a critical assessment.

PubMed

Tervonen, Tommi; Gelhorn, Heather; Sri Bhashyam, Sumitra; Poon, Jiat-Ling; Gries, Katharine S; Rentz, Anne; Marsh, Kevin

2017-12-01

Multiple criteria decision analysis swing weighting (SW) and discrete choice experiments (DCE) are appropriate methods for capturing patient preferences on treatment benefit-risk trade-offs. This paper presents a qualitative comparison of the 2 methods. We review and critically assess similarities and differences of SW and DCE based on 6 aspects: comprehension by study participants, cognitive biases, sample representativeness, ability to capture heterogeneity in preferences, reliability and validity, and robustness of the results. The SW choice task can be more difficult, but the workshop context in which SW is conducted may provide more support to patients who are unfamiliar with the end points being evaluated or who have cognitive impairments. Both methods are similarly prone to a number of biases associated with preference elicitation, and DCE is prone to simplifying heuristics, which limits its application with large number of attributes. The low cost per patient of the DCE means that it can be better at achieving a representative sample, though SW does not require such large sample sizes due to exact nature of the collected preference data. This also means that internal validity is automatically enforced with SW, while the internal validity of DCE results needs to be assessed manually. Choice between the 2 methods depends on characteristics of the benefit-risk assessment, especially on how difficult the trade-offs are for the patients to make and how many patients are available. Although there exist some empirical studies on many of the evaluation aspects, critical evidence gaps remain. Copyright © 2017 John Wiley & Sons, Ltd.

When and Why Is Religious Attendance Associated With Antigay Bias and Gay Rights Opposition? A Justification-Suppression Model Approach.

PubMed

Hoffarth, Mark Romeo; Hodson, Gordon; Molnar, Danielle S

2017-04-24

Even in relatively tolerant countries, antigay bias remains socially divisive, despite being widely viewed as violating social norms of tolerance. From a Justification-Suppression Model (JSM) framework, social norms may generally suppress antigay bias in tolerant countries, yet be "released" by religious justifications among those who resist gay rights progress. Across large, nationally representative US samples (Study 1) and international samples (Study 2, representing a total of 97 different countries), over 215,000 participants, and various indicators of antigay bias (e.g., dislike, moral condemnation, opposing gay rights), individual differences in religious attendance was uniquely associated with greater antigay bias, over and above religious fundamentalism, political ideology, and religious denomination. Moreover, in 4 of 6 multilevel models, religious attendance was associated with antigay bias in countries with greater gay rights recognition, but was unrelated to antigay bias in countries with lower gay rights recognition (Study 2). In Study 3, Google searches for a religious justification ("love the sinner hate the sin") coincided temporally with gay-rights relevant searches. In U.S. (Study 4) and Canadian (Study 5) samples, much of the association between religious attendance and antigay bias was explained by "sinner-sin" religious justification, with religious attendance not associated with antigay bias when respondents reported relatively low familiarity with this justification (Study 5). These findings suggest that social divisions on homosexuality in relatively tolerant social contexts may be in large part due to religious justifications for antigay bias (consistent with the JSM), with important implications for decreasing bias. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Toward a Principled Sampling Theory for Quasi-Orders

PubMed Central

Ünlü, Ali; Schrepp, Martin

2016-01-01

Quasi-orders, that is, reflexive and transitive binary relations, have numerous applications. In educational theories, the dependencies of mastery among the problems of a test can be modeled by quasi-orders. Methods such as item tree or Boolean analysis that mine for quasi-orders in empirical data are sensitive to the underlying quasi-order structure. These data mining techniques have to be compared based on extensive simulation studies, with unbiased samples of randomly generated quasi-orders at their basis. In this paper, we develop techniques that can provide the required quasi-order samples. We introduce a discrete doubly inductive procedure for incrementally constructing the set of all quasi-orders on a finite item set. A randomization of this deterministic procedure allows us to generate representative samples of random quasi-orders. With an outer level inductive algorithm, we consider the uniform random extensions of the trace quasi-orders to higher dimension. This is combined with an inner level inductive algorithm to correct the extensions that violate the transitivity property. The inner level correction step entails sampling biases. We propose three algorithms for bias correction and investigate them in simulation. It is evident that, on even up to 50 items, the new algorithms create close to representative quasi-order samples within acceptable computing time. Hence, the principled approach is a significant improvement to existing methods that are used to draw quasi-orders uniformly at random but cannot cope with reasonably large item sets. PMID:27965601

Toward a Principled Sampling Theory for Quasi-Orders.

PubMed

Ünlü, Ali; Schrepp, Martin

2016-01-01

Quasi-orders, that is, reflexive and transitive binary relations, have numerous applications. In educational theories, the dependencies of mastery among the problems of a test can be modeled by quasi-orders. Methods such as item tree or Boolean analysis that mine for quasi-orders in empirical data are sensitive to the underlying quasi-order structure. These data mining techniques have to be compared based on extensive simulation studies, with unbiased samples of randomly generated quasi-orders at their basis. In this paper, we develop techniques that can provide the required quasi-order samples. We introduce a discrete doubly inductive procedure for incrementally constructing the set of all quasi-orders on a finite item set. A randomization of this deterministic procedure allows us to generate representative samples of random quasi-orders. With an outer level inductive algorithm, we consider the uniform random extensions of the trace quasi-orders to higher dimension. This is combined with an inner level inductive algorithm to correct the extensions that violate the transitivity property. The inner level correction step entails sampling biases. We propose three algorithms for bias correction and investigate them in simulation. It is evident that, on even up to 50 items, the new algorithms create close to representative quasi-order samples within acceptable computing time. Hence, the principled approach is a significant improvement to existing methods that are used to draw quasi-orders uniformly at random but cannot cope with reasonably large item sets.

Association between time perspective and organic food consumption in a large sample of adults.

PubMed

Bénard, Marc; Baudry, Julia; Méjean, Caroline; Lairon, Denis; Giudici, Kelly Virecoulon; Etilé, Fabrice; Reach, Gérard; Hercberg, Serge; Kesse-Guyot, Emmanuelle; Péneau, Sandrine

2018-01-05

Organic food intake has risen in many countries during the past decades. Even though motivations associated with such choice have been studied, psychological traits preceding these motivations have rarely been explored. Consideration of future consequences (CFC) represents the extent to which individuals consider future versus immediate consequences of their current behaviors. Consequently, a future oriented personality may be an important characteristic of organic food consumers. The objective was to analyze the association between CFC and organic food consumption in a large sample of the adult general population. In 2014, a sample of 27,634 participants from the NutriNet-Santé cohort study completed the CFC questionnaire and an Organic-Food Frequency questionnaire. For each food group (17 groups), non-organic food consumers were compared to organic food consumers across quartiles of the CFC using multiple logistic regressions. Moreover, adjusted means of proportions of organic food intakes out of total food intakes were compared between quartiles of the CFC. Analyses were adjusted for socio-demographic, lifestyle and dietary characteristics. Participants with higher CFC were more likely to consume organic food (OR quartile 4 (Q4) vs. Q1 = 1.88, 95% CI: 1.62, 2.20). Overall, future oriented participants were more likely to consume 14 food groups. The strongest associations were observed for starchy refined foods (OR = 1.78, 95% CI: 1.63, 1.94), and fruits and vegetables (OR = 1.74, 95% CI: 1.58, 1.92). The contribution of organic food intake out of total food intake was 33% higher in the Q4 compared to Q1. More precisely, the contribution of organic food consumed was higher in the Q4 for 16 food groups. The highest relative differences between Q4 and Q1 were observed for starchy refined foods (22%) and non-alcoholic beverages (21%). Seafood was the only food group without a significant difference. This study provides information on the personality of organic food consumers in a large sample of adult participants. Consideration of future consequences could represent a significant psychological determinant of organic food consumption.

On the ecological relevance of landscape mapping and its application in the spatial planning of very large marine protected areas.

PubMed

Hogg, Oliver T; Huvenne, Veerle A I; Griffiths, Huw J; Linse, Katrin

2018-06-01

In recent years very large marine protected areas (VLMPAs) have become the dominant form of spatial protection in the marine environment. Whilst seen as a holistic and geopolitically achievable approach to conservation, there is currently a mismatch between the size of VLMPAs, and the data available to underpin their establishment and inform on their management. Habitat mapping has increasingly been adopted as a means of addressing paucity in biological data, through use of environmental proxies to estimate species and community distribution. Small-scale studies have demonstrated environmental-biological links in marine systems. Such links, however, are rarely demonstrated across larger spatial scales in the benthic environment. As such, the utility of habitat mapping as an effective approach to the ecosystem-based management of VLMPAs remains, thus far, largely undetermined. The aim of this study was to assess the ecological relevance of broadscale landscape mapping. Specifically we test the relationship between broad-scale marine landscapes and the structure of their benthic faunal communities. We focussed our work at the sub-Antarctic island of South Georgia, site of one of the largest MPAs in the world. We demonstrate a statistically significant relationship between environmentally derived landscape mapping clusters, and the composition of presence-only species data from the region. To demonstrate this relationship required specific re-sampling of historical species occurrence data to balance biological rarity, biological cosmopolitism, range-restricted sampling and fine-scale heterogeneity between sampling stations. The relationship reveals a distinct biological signature in the faunal composition of individual landscapes, attributing ecological relevance to South Georgia's environmentally derived marine landscape map. We argue therefore, that landscape mapping represents an effective framework for ensuring representative protection of habitats in management plans. Such scientific underpinning of marine spatial planning is critical in balancing the needs of multiple stakeholders whilst maximising conservation payoff. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Colorful Niches of Phytoplankton Shaped by the Spatial Connectivity in a Large River Ecosystem: A Riverscape Perspective

PubMed Central

Frenette, Jean-Jacques; Massicotte, Philippe; Lapierre, Jean-François

2012-01-01

Large rivers represent a significant component of inland waters and are considered sentinels and integrators of terrestrial and atmospheric processes. They represent hotspots for the transport and processing of organic and inorganic material from the surrounding landscape, which ultimately impacts the bio-optical properties and food webs of the rivers. In large rivers, hydraulic connectivity operates as a major forcing variable to structure the functioning of the riverscape, and–despite increasing interest in large-river studies–riverscape structural properties, such as the underwater spectral regime, and their impact on autotrophic ecological processes remain poorly studied. Here we used the St. Lawrence River to identify the mechanisms structuring the underwater spectral environment and their consequences on pico- and nanophytoplankton communities, which are good biological tracers of environmental changes. Our results, obtained from a 450 km sampling transect, demonstrate that tributaries exert a profound impact on the receiving river’s photosynthetic potential. This occurs mainly through injection of chromophoric dissolved organic matter (CDOM) and non-algal material (tripton). CDOM and tripton in the water column selectively absorbed wavelengths in a gradient from blue to red, and the resulting underwater light climate was in turn a strong driver of the phytoplankton community structure (prokaryote/eukaryote relative and absolute abundances) at scales of many kilometers from the tributary confluence. Our results conclusively demonstrate the proximal impact of watershed properties on underwater spectral composition in a highly dynamic river environment characterized by unique structuring properties such as high directional connectivity, numerous sources and forms of carbon, and a rapidly varying hydrodynamic regime. We surmise that the underwater spectral composition represents a key integrating and structural property of large, heterogeneous river ecosystems and a promising tool to study autotrophic functional properties. It confirms the usefulness of using the riverscape approach to study large-river ecosystems and initiate comparison along latitudinal gradients. PMID:22558259

Modeling the development of written language

PubMed Central

Puranik, Cynthia S.; Foorman, Barbara; Foster, Elizabeth; Wilson, Laura Gehron; Tschinkel, Erika; Kantor, Patricia Thatcher

2011-01-01

Alternative models of the structure of individual and developmental differences of written composition and handwriting fluency were tested using confirmatory factor analysis of writing samples provided by first- and fourth-grade students. For both groups, a five-factor model provided the best fit to the data. Four of the factors represented aspects of written composition: macro-organization (use of top sentence and number and ordering of ideas), productivity (number and diversity of words used), complexity (mean length of T-unit and syntactic density), and spelling and punctuation. The fifth factor represented handwriting fluency. Handwriting fluency was correlated with written composition factors at both grades. The magnitude of developmental differences between first grade and fourth grade expressed as effect sizes varied for variables representing the five constructs: large effect sizes were found for productivity and handwriting fluency variables; moderate effect sizes were found for complexity and macro-organization variables; and minimal effect sizes were found for spelling and punctuation variables. PMID:22228924

Bacteria associated with Amblyomma cajennense tick eggs

PubMed Central

Machado-Ferreira, Erik; Vizzoni, Vinicius Figueiredo; Piesman, Joseph; Gazeta, Gilberto Salles; Soares, Carlos Augusto Gomes

2015-01-01

Abstract Ticks represent a large group of pathogen vectors that blood feed on a diversity of hosts. In the Americas, the Ixodidae ticks Amblyomma cajennense are responsible for severe impact on livestock and public health. In the present work, we present the isolation and molecular identification of a group of culturable bacteria associated with A. cajennense eggs from females sampled in distinct geographical sites in southeastern Brazil. Additional comparative analysis of the culturable bacteria from Anocentor nitens, Rhipicephalus sanguineus and Ixodes scapularis tick eggs were also performed. 16S rRNA gene sequence analyses identified 17 different bacterial types identified as Serratia marcescens, Stenotrophomonas maltophilia, Pseudomonas fluorescens, Enterobacter spp., Micrococcus luteus, Ochrobactrum anthropi, Bacillus cereus and Staphylococcus spp., distributed in 12 phylogroups. Staphylococcus spp., especially S. sciuri, was the most prevalent bacteria associated with A. cajennense eggs, occurring in 65% of the samples and also frequently observed infecting A. nitens eggs. S. maltophilia, S. marcescens and B. cereus occurred infecting eggs derived from specific sampling sites, but in all cases rising almost as pure cultures from infected A. cajennense eggs. The potential role of these bacterial associations is discussed and they possibly represent new targets for biological control strategies of ticks and tick borne diseases. PMID:26537602

Surface-water-quality assessment of the Upper Illinois River basin in Illinois, Indiana, and Wisconsin; cross-sectional and depth variation of water-quality constituents and properties in the Upper Illinois River basin, 1987-88

USGS Publications Warehouse

Marron, Donna C.; Blanchard, Stephen F.

1995-01-01

Data on water velocity, temperature, specific con- ductance, pH, dissolved oxygen concentration, chlorophyll concentration, suspended sediment con- centration, fecal-coliform counts, and the percen- tage of suspended sediment finer than 62 micrometers ranged up to 21 percent; and cross-section coefficients of variation of the concentrations of suspended sediment, fecal coliform, and chlorophyll ranged from 7 to 115 percent. Midchannel measure- ments of temperature, specific conductance, and pH were within 5 percent of mean cross-sectional values of these properties at the eight sampling sites, most of which appear well mixed because of the effect of dams and reservoirs. Measurements of the concentration of dissolved oxygen at various cross- section locations and at variable sampling depths are required to obtain a representative value of this constituent at these sites. The large varia- bility of concentrations of chlorophyll and suspended sediment, and fecal-coliform counts at the eight sampling sites indicates that composite rather than midchannel or mean values of these constituents are likely to be most representative of the channel cross section.

Fast Physically Accurate Rendering of Multimodal Signatures of Distributed Fracture in Heterogeneous Materials.

PubMed

Visell, Yon

2015-04-01

This paper proposes a fast, physically accurate method for synthesizing multimodal, acoustic and haptic, signatures of distributed fracture in quasi-brittle heterogeneous materials, such as wood, granular media, or other fiber composites. Fracture processes in these materials are challenging to simulate with existing methods, due to the prevalence of large numbers of disordered, quasi-random spatial degrees of freedom, representing the complex physical state of a sample over the geometric volume of interest. Here, I develop an algorithm for simulating such processes, building on a class of statistical lattice models of fracture that have been widely investigated in the physics literature. This algorithm is enabled through a recently published mathematical construction based on the inverse transform method of random number sampling. It yields a purely time domain stochastic jump process representing stress fluctuations in the medium. The latter can be readily extended by a mean field approximation that captures the averaged constitutive (stress-strain) behavior of the material. Numerical simulations and interactive examples demonstrate the ability of these algorithms to generate physically plausible acoustic and haptic signatures of fracture in complex, natural materials interactively at audio sampling rates.

The prevalence of compulsive hoarding and its association with compulsive buying in a German population-based sample.

PubMed

Mueller, Astrid; Mitchell, James E; Crosby, Ross D; Glaesmer, Heide; de Zwaan, Martina

2009-08-01

The aims of the study were to estimate the prevalence rate of compulsive hoarding, and to determine the association between compulsive hoarding and compulsive buying in a nationally representative sample of the German population (N = 2307). Compulsive hoarding was assessed with the German version of the Saving Inventory-Revised (SI-R; Frost, R.O., Steketee, G., & Grisham, J. (2004). Measurement of compulsive hoarding: saving inventory-revised. Behaviour Research and Therapy, 42, 1163-1182.). The point prevalence of compulsive hoarding was estimated to be 4.6%. Individuals with compulsive hoarding did not differ significantly from those without compulsive hoarding regarding age, gender, and other sociodemographic characteristics. Significant correlations were found between the compulsive hoarding and the compulsive buying measures. Participants with compulsive hoarding reported a higher propensity to compulsive buying than respondents without hoarding. About two thirds of participants classified as having compulsive hoarding were also defined as suffering from compulsive buying. In summary, these results suggest that compulsive hoarding may be relatively prevalent in Germany and they confirm the close association between compulsive hoarding and compulsive buying through the investigation of a large scale representative sample.

Evaluating performance of stormwater sampling approaches using a dynamic watershed model.

PubMed

Ackerman, Drew; Stein, Eric D; Ritter, Kerry J

2011-09-01

Accurate quantification of stormwater pollutant levels is essential for estimating overall contaminant discharge to receiving waters. Numerous sampling approaches exist that attempt to balance accuracy against the costs associated with the sampling method. This study employs a novel and practical approach of evaluating the accuracy of different stormwater monitoring methodologies using stormflows and constituent concentrations produced by a fully validated continuous simulation watershed model. A major advantage of using a watershed model to simulate pollutant concentrations is that a large number of storms representing a broad range of conditions can be applied in testing the various sampling approaches. Seventy-eight distinct methodologies were evaluated by "virtual samplings" of 166 simulated storms of varying size, intensity and duration, representing 14 years of storms in Ballona Creek near Los Angeles, California. The 78 methods can be grouped into four general strategies: volume-paced compositing, time-paced compositing, pollutograph sampling, and microsampling. The performances of each sampling strategy was evaluated by comparing the (1) median relative error between the virtually sampled and the true modeled event mean concentration (EMC) of each storm (accuracy), (2) median absolute deviation about the median or "MAD" of the relative error or (precision), and (3) the percentage of storms where sampling methods were within 10% of the true EMC (combined measures of accuracy and precision). Finally, costs associated with site setup, sampling, and laboratory analysis were estimated for each method. Pollutograph sampling consistently outperformed the other three methods both in terms of accuracy and precision, but was the most costly method evaluated. Time-paced sampling consistently underestimated while volume-paced sampling over estimated the storm EMCs. Microsampling performance approached that of pollutograph sampling at a substantial cost savings. The most efficient method for routine stormwater monitoring in terms of a balance between performance and cost was volume-paced microsampling, with variable sample pacing to ensure that the entirety of the storm was captured. Pollutograph sampling is recommended if the data are to be used for detailed analysis of runoff dynamics.

Petrology and geochemistry of lithic fragments separated from the Apollo 15 deep-drill core

NASA Technical Reports Server (NTRS)

Lindstrom, M. M.; Nielsen, R. L.; Drake, M. J.

1977-01-01

Petrological and geochemical analysis of lithic fragments separated from the Apollo 15 deep-drill core showed these fragments to fall into the essentially the same range of rock types as observed in surface soil samples and large rock samples. Three particles are singled out as being of special interest. One sample is a mare basalt containing extremely evolved phases. The particle may represent small-scale imperfect crystal/liquid separation in a lava flow. A green glass particle is not the ultramafic emerald green glass described from the Apollo 15 site, but rather an ANT-like light green color, and has a quite different chemical composition from the ultramafic variety. One mare basalt displays a positive Eu anomaly and is enriched in plagioclase relative to olivine plus pyroxene.

Job stress and cardiovascular disease: a theoretic critical review.

PubMed

Kristensen, T S

1996-07-01

During the last 15 years, the research on job stress and cardiovascular diseases has been dominated by the job strain model developed by R. Karasek (1979) and colleagues (R. Karasek & T. Theorell, 1990). In this article the results of this research are briefly summarized, and the theoretical and methodological basis is discussed and criticized. A sociological interpretation of the model emphasizing theories of technological change, qualifications of the workers, and the organization of work is proposed. Furthermore, improvements with regard to measuring the job strain dimensions and to sampling the study base are suggested. Substantial improvements of the job strain research could be achieved if the principle of triangulation were used in the measurements of stressors, stress, and sickness and if occupation-based samples were used instead of large representative samples.

The measurement equivalence of Big Five factor markers for persons with different levels of education.

PubMed

Rammstedt, Beatrice; Goldberg, Lewis R; Borg, Ingwer

2010-02-01

Previous findings suggest that the Big-Five factor structure is not guaranteed in samples with lower educational levels. The present study investigates the Big-Five factor structure in two large samples representative of the German adult population. In both samples, the Big-Five factor structure emerged only in a blurry way at lower educational levels, whereas for highly educated persons it emerged with textbook-like clarity. Because well-educated persons are most comparable to the usual subjects of psychological research, it might be asked if the Big Five are limited to such persons. Our data contradict this conclusion. There are strong individual differences in acquiescence response tendencies among less highly educated persons. After controlling for this bias the Big-Five model holds at all educational levels.

Ground-water resources of the lower Niobrara River and Ponca Creek basins, Nebraska and South Dakota

USGS Publications Warehouse

Newport, Thomas G.; Krieger, Robert A.

1959-01-01

 The report contains an annotated bibliography of previous publications on the geology and ground-water resources of the area, brief descriptions of the Cretaceous, Tertiary, and Quaternary rocks, a map showing the contour of the water table, logs of test holes and wells not published elsewhere, results of analyses of ground- and surface-water samples, and records of all wells of large discharge and representative wells of small discharge.

Skills of U.S. Unemployed, Young, and Older Adults in Sharper Focus: Results from the Program for the International Assessment of Adult Competencies (PIAAC) 2012/2014. First Look. NCES 2016-039rev

ERIC Educational Resources Information Center

Rampey, Bobby D.; Finnegan, Robert; Mohadjer, Leyla; Krenzke, Tom; Hogan, Jacquie; Provasnik, Stephen

2016-01-01

The Program for the International Assessment of Adult Competencies (PIAAC) is a cyclical, large-scale study of adult skills and life experiences focusing on education and employment. Nationally representative samples of adults between the ages of 16 and 65 are administered an assessment of literacy, numeracy, and problem solving in technology rich…

JPRS Report, Science & Technology, Japan, Government and Private Sector Joint R&D Projects

DTIC Science & Technology

1988-08-16

is that if this system uses exogenous genes represented by the DNA that codes for hepatitis B surface antigen, polyvaccines can be produced easily...that can express in large quantities molecular clones of genetic products is awaited. Vectors using cells of higher mammals including man have been...functions of IVM and MMD using cultured spinal nerve cells with a great advantage that the same sample can be used for both electrophysiological and

Sampling procedures for inventory of commercial volume tree species in Amazon Forest.

PubMed

Netto, Sylvio P; Pelissari, Allan L; Cysneiros, Vinicius C; Bonazza, Marcelo; Sanquetta, Carlos R

2017-01-01

The spatial distribution of tropical tree species can affect the consistency of the estimators in commercial forest inventories, therefore, appropriate sampling procedures are required to survey species with different spatial patterns in the Amazon Forest. For this, the present study aims to evaluate the conventional sampling procedures and introduce the adaptive cluster sampling for volumetric inventories of Amazonian tree species, considering the hypotheses that the density, the spatial distribution and the zero-plots affect the consistency of the estimators, and that the adaptive cluster sampling allows to obtain more accurate volumetric estimation. We use data from a census carried out in Jamari National Forest, Brazil, where trees with diameters equal to or higher than 40 cm were measured in 1,355 plots. Species with different spatial patterns were selected and sampled with simple random sampling, systematic sampling, linear cluster sampling and adaptive cluster sampling, whereby the accuracy of the volumetric estimation and presence of zero-plots were evaluated. The sampling procedures applied to species were affected by the low density of trees and the large number of zero-plots, wherein the adaptive clusters allowed concentrating the sampling effort in plots with trees and, thus, agglutinating more representative samples to estimate the commercial volume.

A geostatistical approach to predicting sulfur content in the Pittsburgh coal bed

USGS Publications Warehouse

Watson, W.D.; Ruppert, L.F.; Bragg, L.J.; Tewalt, S.J.

2001-01-01

The US Geological Survey (USGS) is completing a national assessment of coal resources in the five top coal-producing regions in the US. Point-located data provide measurements on coal thickness and sulfur content. The sample data and their geologic interpretation represent the most regionally complete and up-to-date assessment of what is known about top-producing US coal beds. The sample data are analyzed using a combination of geologic and Geographic Information System (GIS) models to estimate tonnages and qualities of the coal beds. Traditionally, GIS practitioners use contouring to represent geographical patterns of "similar" data values. The tonnage and grade of coal resources are then assessed by using the contour lines as references for interpolation. An assessment taken to this point is only indicative of resource quantity and quality. Data users may benefit from a statistical approach that would allow them to better understand the uncertainty and limitations of the sample data. To develop a quantitative approach, geostatistics were applied to the data on coal sulfur content from samples taken in the Pittsburgh coal bed (located in the eastern US, in the southwestern part of the state of Pennsylvania, and in adjoining areas in the states of Ohio and West Virginia). Geostatistical methods that account for regional and local trends were applied to blocks 2.7 mi (4.3 km) on a side. The data and geostatistics support conclusions concerning the average sulfur content and its degree of reliability at regional- and economic-block scale over the large, contiguous part of the Pittsburgh outcrop, but not to a mine scale. To validate the method, a comparison was made with the sulfur contents in sample data taken from 53 coal mines located in the study area. The comparison showed a high degree of similarity between the sulfur content in the mine samples and the sulfur content represented by the geostatistically derived contours. Published by Elsevier Science B.V.

School Progress Among Children of Same-Sex Couples.

PubMed

Watkins, Caleb S

2018-06-01

This study uses logit regressions on a pooled sample of children from the 2012, 2013, and 2014 American Community Survey to perform a nationally representative analysis of school progress for a large sample of 4,430 children who reside with same-sex couples. Odds ratios from regressions that compare children between different-sex married couples and same-sex couples fail to show significant differences in normal school progress between households across a variety of sample compositions. Likewise, marginal effects from regressions that compare children with similar family dynamics between different-sex married couples and same-sex couples fail to predict significantly higher probabilities of grade retention for children of same-sex couples. Significantly lower grade retention rates are sometimes predicted for children of same-sex couples than for different-sex married couples, but these differences are sensitive to sample exclusions and do not indicate causal benefits to same-sex parenting.

Micropollutants and chemical residues in organic and conventional meat.

PubMed

Dervilly-Pinel, Gaud; Guérin, Thierry; Minvielle, Brice; Travel, Angélique; Normand, Jérôme; Bourin, Marie; Royer, Eric; Dubreil, Estelle; Mompelat, Sophie; Hommet, Frédéric; Nicolas, Marina; Hort, Vincent; Inthavong, Chanthadary; Saint-Hilaire, Mailie; Chafey, Claude; Parinet, Julien; Cariou, Ronan; Marchand, Philippe; Le Bizec, Bruno; Verdon, Eric; Engel, Erwan

2017-10-01

The chemical contamination levels of both conventional and organic meats were assessed. The objective was to provide occurrence data in a context of chronic exposure. Environmental contaminants (17 polychlorinated dibenzodioxins/dibenzofurans, 18 polychlorinated biphenyls (PCBs), 3 hexabromocyclododecane (HBCD) isomers, 6 mycotoxins, 6 inorganic compounds) together with chemical residues arising from production inputs (75 antimicrobials, 10 coccidiostats and 121 pesticides) have been selected as relevant compounds. A dedicated sampling strategy, representative of the French production allowed quantification of a large sample set (n=266) including both conventional (n=139) and organic (n=127) raw meat from three animal species (bovine, porcine, poultry). While contamination levels below regulatory limits were measured in all the samples, significant differences were observed between both species and types of farming. Several environmental contaminants (Dioxins, PCBs, HBCD, Zn, Cu, Cd, Pb, As) were measured at significantly higher levels in organic samples. Copyright © 2017 Elsevier Ltd. All rights reserved.

Automated Phase Segmentation for Large-Scale X-ray Diffraction Data Using a Graph-Based Phase Segmentation (GPhase) Algorithm.

PubMed

Xiong, Zheng; He, Yinyan; Hattrick-Simpers, Jason R; Hu, Jianjun

2017-03-13

The creation of composition-processing-structure relationships currently represents a key bottleneck for data analysis for high-throughput experimental (HTE) material studies. Here we propose an automated phase diagram attribution algorithm for HTE data analysis that uses a graph-based segmentation algorithm and Delaunay tessellation to create a crystal phase diagram from high throughput libraries of X-ray diffraction (XRD) patterns. We also propose the sample-pair based objective evaluation measures for the phase diagram prediction problem. Our approach was validated using 278 diffraction patterns from a Fe-Ga-Pd composition spread sample with a prediction precision of 0.934 and a Matthews Correlation Coefficient score of 0.823. The algorithm was then applied to the open Ni-Mn-Al thin-film composition spread sample to obtain the first predicted phase diagram mapping for that sample.

User's guide for polyethylene-based passive diffusion bag samplers to obtain volatile organic compound concentrations in wells. Part I, Deployment, recovery, data interpretation, and quality control and assurance

USGS Publications Warehouse

Vroblesky, Don A.

2001-01-01

Diffusion samplers installed in observation wells were found to be capable of yielding representative water samples for chlorinated volatile organic compounds. The samplers consisted of polyethylene bags containing deionized water and relied on diffusion of chlorinated volatile organic compounds through the polyethylene membrane. The known ability of polyethylene to transmit other volatile compounds, such as benzene and toluene, indicates that the samplers can be used for a variety of volatile organic compounds. In wells at the study area, the volatile organic compound concentrations in water samples obtained using the samplers without prior purging were similar to concentrations in water samples obtained from the respective wells using traditional purging and sampling approaches. The low cost associated with this approach makes it a viable option for monitoring large observation-well networks for volatile organic compounds.

User's guide for polyethylene-based passive diffusion bag samplers to obtain volatile organic compound concentrations in wells. Part 2, Field tests

USGS Publications Warehouse

Vroblesky, Don A.

2001-01-01

Diffusion samplers installed in observation wells were found to be capable of yielding representative water samples for chlorinated volatile organic compounds. The samplers consisted of polyethylene bags containing deionized water and relied on diffusion of chlorinated volatile organic compounds through the polyethylene membrane. The known ability of polyethylene to transmit other volatile compounds, such as benzene and toluene, indicates that the samplers can be used for a variety of volatile organic compounds. In wells at the study area, the volatile organic compound concentrations in water samples obtained using the samplers without prior purging were similar to concentrations in water samples obtained from the respective wells using traditional purging and sampling approaches. The low cost associated with this approach makes it a viable option for monitoring large observation-well networks for volatile organic compounds.

40 CFR Appendix I to Part 261 - Representative Sampling Methods

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 27 2013-07-01 2013-07-01 false Representative Sampling Methods I Appendix I to Part 261 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES...—Representative Sampling Methods The methods and equipment used for sampling waste materials will vary with the...

People with alcohol use disorders in specialized care in eight different European countries.

PubMed

Rehm, Jürgen; Allamani, Allaman; Aubin, Henri-Jean; Della Vedova, Roberto; Elekes, Zsuzsanna; Frick, Ulrich; Jakubczyk, Andrzej; Kostogianni, Nikoleta; Landsmane, Inga; Manthey, Jakob; Miquel, Laia; Paille, François; Pieper, Lars; Probst, Charlotte; Scafuri, Francesca; Shield, Kevin D; Snikere, Sigita; Struzzo, Pierluigi; Trapencieris, Marcis; Voller, Fabio; Wittchen, Hans-Ulrich; Gual, Antoni; Wojnar, Marcin

2015-05-01

To provide a description of patients receiving alcohol treatment in eight different European countries, including the level of comorbidities and functional limitations. Drinking behaviours, DSM-IV alcohol use disorder (AUD), mental and somatic comorbidities, disability and health services utilization of 1767 patients from various specialized treatment settings were assessed as representative for regions of eight European countries. Severity of alcohol dependence (AD) in terms of drinking level was compared with a large representative US sample. Patients in specialized care for AUDs showed high levels of consumption [average level of daily ethanol intake: 141.1 g, standard deviation (SD): 116.0 g], comorbidity [e.g. liver problems: 19.6%, 95% confidence interval (CI): 17.5-21.6%; depression: 43.2%, 95% CI: 40.7-45.8%; anxiety: 50.3%, 95% CI: 47.8-52.9%], disability and health services utilization (average number of nights spent in hospital(s) during the last 6 months: 8.8, SD: 19.5 nights). Severity of AD was similar to the US sample, but European men consumed on average more alcohol daily. High levels of consumption, somatic and mental comorbidities, disability and functional losses were found in this representative treatment sample, indicating that treatment was initiated only at severe stages of AUDs. Earlier initiation of treatment could help avoid some of the health and social burden. © The Author 2015. Medical Council on Alcohol and Oxford University Press. All rights reserved.

Individuals with fibromyalgia and depression: findings from a nationally representative Canadian survey.

PubMed

Fuller-Thomson, Esme; Nimigon-Young, Jodie; Brennenstuhl, Sarah

2012-04-01

The aim of the study is to determine the prevalence of and factors associated with major depression among those with Fibromyalgia Syndrome (FMS) in a Canadian representative sample. The study was a secondary analysis of a large, nationally representative sample from the Canadian Community Health Survey. The full sample (n = 126,805) was used to determine the prevalence of FMS and odds ratio of depression among those with FMS (n = 1,635) compared to those without (n = 125,170). A subsample of those with FMS (n = 1,635) was used to determine the prevalence of major depression and the demographic, psychosocial and health-related factors associated with it. Those with FMS had approximately three times higher odds of depression in comparison with those without FMS, even when controlling for important socio-demographic characteristics (OR = 2.90; 95% CI = 2.52, 3.33). Based on the subsample of those with FMS, it was found that 22% had current major depression. A multivariate logistic regression model of those with FMS showed depression was associated with younger age, female gender, being unmarried, food insecurity, number of chronic conditions, and limitations in activities. Two-fifths of those with depression and FMS had not discussed mental health concerns with any health professionals in the previous year, highlighting the underuse of mental health services and the need for health professionals to increase screening within this population. The findings may help clinicians target mental health assessments and interventions for their patients with fibromyalgia.

Application of a luminescent bacterial biosensor for the detection of tetracyclines in routine analysis of poultry muscle samples.

PubMed

Pikkemaat, M G; Rapallini, M L B A; Karp, M T; Elferink, J W A

2010-08-01

Tetracyclines are extensively used in veterinary medicine. For the detection of tetracycline residues in animal products, a broad array of methods is available. Luminescent bacterial biosensors represent an attractive inexpensive, simple and fast method for screening large numbers of samples. A previously developed cell-biosensor method was subjected to an evaluation study using over 300 routine poultry samples and the results were compared with a microbial inhibition test. The cell-biosensor assay yielded many more suspect samples, 10.2% versus 2% with the inhibition test, which all could be confirmed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Only one sample contained a concentration above the maximum residue limit (MRL) of 100 microg kg(-1), while residue levels in most of the suspect samples were very low (<10 microg kg(-1)). The method appeared to be specific and robust. Using an experimental set-up comprising the analysis of a series of three sample dilutions allowed an appropriate cut-off for confirmatory analysis, limiting the number of samples and requiring further analysis to a minimum.

Exactly solvable random graph ensemble with extensively many short cycles

NASA Astrophysics Data System (ADS)

Aguirre López, Fabián; Barucca, Paolo; Fekom, Mathilde; Coolen, Anthony C. C.

2018-02-01

We introduce and analyse ensembles of 2-regular random graphs with a tuneable distribution of short cycles. The phenomenology of these graphs depends critically on the scaling of the ensembles’ control parameters relative to the number of nodes. A phase diagram is presented, showing a second order phase transition from a connected to a disconnected phase. We study both the canonical formulation, where the size is large but fixed, and the grand canonical formulation, where the size is sampled from a discrete distribution, and show their equivalence in the thermodynamical limit. We also compute analytically the spectral density, which consists of a discrete set of isolated eigenvalues, representing short cycles, and a continuous part, representing cycles of diverging size.

COMPARISON OF ECOLOGICAL COMMUNITIES: THE PROBLEM OF SAMPLE REPRESENTATIVENESS

EPA Science Inventory

Obtaining an adequate, representative sample of ecological communities to make taxon richness (TR) or compositional comparisons among sites is a continuing challenge. Sample representativeness literally means the similarity in species composition and relative abundance between a ...

Efficient ICCG on a shared memory multiprocessor

NASA Technical Reports Server (NTRS)

Hammond, Steven W.; Schreiber, Robert

1989-01-01

Different approaches are discussed for exploiting parallelism in the ICCG (Incomplete Cholesky Conjugate Gradient) method for solving large sparse symmetric positive definite systems of equations on a shared memory parallel computer. Techniques for efficiently solving triangular systems and computing sparse matrix-vector products are explored. Three methods for scheduling the tasks in solving triangular systems are implemented on the Sequent Balance 21000. Sample problems that are representative of a large class of problems solved using iterative methods are used. We show that a static analysis to determine data dependences in the triangular solve can greatly improve its parallel efficiency. We also show that ignoring symmetry and storing the whole matrix can reduce solution time substantially.

Simulator for multilevel optimization research

NASA Technical Reports Server (NTRS)

Padula, S. L.; Young, K. C.

1986-01-01

A computer program designed to simulate and improve multilevel optimization techniques is described. By using simple analytic functions to represent complex engineering analyses, the simulator can generate and test a large variety of multilevel decomposition strategies in a relatively short time. This type of research is an essential step toward routine optimization of large aerospace systems. The paper discusses the types of optimization problems handled by the simulator and gives input and output listings and plots for a sample problem. It also describes multilevel implementation techniques which have value beyond the present computer program. Thus, this document serves as a user's manual for the simulator and as a guide for building future multilevel optimization applications.

Pilot Test of a Novel Method for Assessing Community Response to Low-Amplitude Sonic Booms

NASA Technical Reports Server (NTRS)

Fidell, Sanford; Horonjeff, Richard D.; Harris, Michael

2012-01-01

A pilot test of a novel method for assessing residents annoyance to sonic booms was performed. During a two-week period, residents of the base housing area at Edwards Air Force Base provided data on their reactions to sonic booms using Smartphone-based interviews. Noise measurements were conducted at the same time. The report presents information about data collection methods and about test participants reactions to low-amplitude sonic booms. The latter information should not be viewed as definitive for several reasons. It may not be reliably generalized to the wider U.S. residential population (because it was not derived from a representative random sample) and the sample itself was not large.

Higher male educational hypergamy: evidence from Portugal.

PubMed

Correia, Hamilton R

2003-04-01

Studies of human mate choice have been based almost exclusively on stated preferences and personal advertisements, and the external validity of such studies has therefore been questioned. In the present study, real-life matings based on a large representative sample of newly wed couples in 1998 (n=66,598) were analysed according to educational assortative mating. The results demonstrate a strong educational homogamy in this national Portuguese sample. However, men tend to marry women who are slightly more educated than themselves. The results are compared with those of a modern society (US, 1940-87) and a traditional society (Kipsigis, 1952-91). Since educational attainment is strongly associated with social status and intelligence, these results are discussed in an evolutionary perspective.

VizieR Online Data Catalog: The ESO DIBs Large Exploration Survey (Cox+, 2017)

NASA Astrophysics Data System (ADS)

Cox, N. L. J.; Cami, J.; Farhang, A.; Smoker, J.; Monreal-Ibero, A.; Lallement, R.; Sarre, P. J.; Marshall, C. C. M.; Smith, K. T.; Evans, C. J.; Royer, P.; Linnartz, H.; Cordiner, M. A.; Joblin, C.; van Loon, J. T.; Foing, B. H.; Bhatt, N. H.; Bron, E.; Elyajouri, M.; de Koter, A.; Ehrenfreund, P.; Javadi, A.; Kaper, L.; Khosroshadi, H. G.; Laverick, M.; Le Petit, F.; Mulas, G.; Roueff, E.; Salama, F.; Spaans, M.

2018-01-01

We constructed a statistically representative survey sample that probes a wide range of interstellar environment parameters including reddening E(B-V), visual extinction AV, total-to-selective extinction ratio RV, and molecular hydrogen fraction fH2. EDIBLES provides the community with optical (~305-1042nm) spectra at high spectral resolution (R~70000 in the blue arm and 100000 in the red arm) and high signal-to-noise (S/N; median value ~500-1000), for a statistically significant sample of interstellar sightlines. Many of the >100 sightlines included in the survey already have auxiliary available ultraviolet, infrared and/or polarisation data on the dust and gas components. (2 data files).

Prevalence of Female Urinary Incontinence in the General Population According to Different Definitions and Study Designs.

PubMed

Bedretdinova, Dina; Fritel, Xavier; Panjo, Henri; Ringa, Virginie

2016-02-01

Estimates of the prevalence of female urinary incontinence (UI) vary widely. To estimate UI prevalence among women in France using data from five national surveys and analyse prevalence differences among the surveys according to their design (representative sample or not, survey focused on UI or not) and UI definition (based on symptoms or disease perception). Data came from two representative telephone surveys, Fecond (5017 women aged 15-49 yr) and Barometer (3089 women aged 40-85 yr), general and urinary postal surveys of the GAZEL cohort (3098 women aged 54-69 yr), and the web-based NutriNet survey (85,037 women aged 18-87 yr). Definitions of UI based on the International Conference on Incontinence Questionnaire UI short form (ICIQ-UI-SF) and on a list of health problems were considered. We compared age-adjusted prevalence rates among studies via logistic regression and generalised linear models. Overall, 13% of the women in Fecond, 24% in Barometer, 15% in the GAZEL general survey, 39% in the GAZEL urinary survey, and 1.5% in the NutriNet survey reported any UI. Prevalence rates in representative samples with the same UI definition (ICIQ-UI-SF) were concordant. UI prevalence in the representative samples was 17%. The estimated number of women in France with UI was 5.35 million (95% confidence interval [CI] 5.34-5.36 million) for any UI and 1.54 million (95% CI 1.53-1.55 million) for daily UI. For the GAZEL sample, UI prevalence was lower but UI severity was greater for responses to a questionnaire with the list-based UI definition rather than to a questionnaire with the ICIQ-UI-SF-based definition. In all surveys, information about UI was self-reported and was not validated by objective measurements. UI definitions and sampling strategies influence estimates of UI prevalence among women. Precise estimates of UI prevalence should be based on non-UI-focused surveys among representative samples and using a validated standardised symptom-based questionnaire. We looked at estimates of urinary incontinence (UI) prevalence in studies with different designs and different UI definitions in a large population of French women. We found that estimates varied with the definition and the design. We conclude that the most precise estimates of UI prevalence are obtained in studies of representative populations that are not focused on UI and use a validated international standard questionnaire with sufficient details to allow grading of UI severity. Most women reported rare urine leakages involving small amounts of urine with little impact on their quality of life. Copyright © 2015 European Association of Urology. Published by Elsevier B.V. All rights reserved.

A Bayesian nonparametric method for prediction in EST analysis

PubMed Central

Lijoi, Antonio; Mena, Ramsés H; Prünster, Igor

2007-01-01

Background Expressed sequence tags (ESTs) analyses are a fundamental tool for gene identification in organisms. Given a preliminary EST sample from a certain library, several statistical prediction problems arise. In particular, it is of interest to estimate how many new genes can be detected in a future EST sample of given size and also to determine the gene discovery rate: these estimates represent the basis for deciding whether to proceed sequencing the library and, in case of a positive decision, a guideline for selecting the size of the new sample. Such information is also useful for establishing sequencing efficiency in experimental design and for measuring the degree of redundancy of an EST library. Results In this work we propose a Bayesian nonparametric approach for tackling statistical problems related to EST surveys. In particular, we provide estimates for: a) the coverage, defined as the proportion of unique genes in the library represented in the given sample of reads; b) the number of new unique genes to be observed in a future sample; c) the discovery rate of new genes as a function of the future sample size. The Bayesian nonparametric model we adopt conveys, in a statistically rigorous way, the available information into prediction. Our proposal has appealing properties over frequentist nonparametric methods, which become unstable when prediction is required for large future samples. EST libraries, previously studied with frequentist methods, are analyzed in detail. Conclusion The Bayesian nonparametric approach we undertake yields valuable tools for gene capture and prediction in EST libraries. The estimators we obtain do not feature the kind of drawbacks associated with frequentist estimators and are reliable for any size of the additional sample. PMID:17868445

Immunophenotype Discovery, Hierarchical Organization, and Template-Based Classification of Flow Cytometry Samples

DOE PAGES

Azad, Ariful; Rajwa, Bartek; Pothen, Alex

2016-08-31

We describe algorithms for discovering immunophenotypes from large collections of flow cytometry samples and using them to organize the samples into a hierarchy based on phenotypic similarity. The hierarchical organization is helpful for effective and robust cytometry data mining, including the creation of collections of cell populations’ characteristic of different classes of samples, robust classification, and anomaly detection. We summarize a set of samples belonging to a biological class or category with a statistically derived template for the class. Whereas individual samples are represented in terms of their cell populations (clusters), a template consists of generic meta-populations (a group ofmore » homogeneous cell populations obtained from the samples in a class) that describe key phenotypes shared among all those samples. We organize an FC data collection in a hierarchical data structure that supports the identification of immunophenotypes relevant to clinical diagnosis. A robust template-based classification scheme is also developed, but our primary focus is in the discovery of phenotypic signatures and inter-sample relationships in an FC data collection. This collective analysis approach is more efficient and robust since templates describe phenotypic signatures common to cell populations in several samples while ignoring noise and small sample-specific variations. We have applied the template-based scheme to analyze several datasets, including one representing a healthy immune system and one of acute myeloid leukemia (AML) samples. The last task is challenging due to the phenotypic heterogeneity of the several subtypes of AML. However, we identified thirteen immunophenotypes corresponding to subtypes of AML and were able to distinguish acute promyelocytic leukemia (APL) samples with the markers provided. Clinically, this is helpful since APL has a different treatment regimen from other subtypes of AML. Core algorithms used in our data analysis are available in the flowMatch package at www.bioconductor.org. It has been downloaded nearly 6,000 times since 2014.« less

Immunophenotype Discovery, Hierarchical Organization, and Template-Based Classification of Flow Cytometry Samples

DOE Office of Scientific and Technical Information (OSTI.GOV)

Azad, Ariful; Rajwa, Bartek; Pothen, Alex

We describe algorithms for discovering immunophenotypes from large collections of flow cytometry samples and using them to organize the samples into a hierarchy based on phenotypic similarity. The hierarchical organization is helpful for effective and robust cytometry data mining, including the creation of collections of cell populations’ characteristic of different classes of samples, robust classification, and anomaly detection. We summarize a set of samples belonging to a biological class or category with a statistically derived template for the class. Whereas individual samples are represented in terms of their cell populations (clusters), a template consists of generic meta-populations (a group ofmore » homogeneous cell populations obtained from the samples in a class) that describe key phenotypes shared among all those samples. We organize an FC data collection in a hierarchical data structure that supports the identification of immunophenotypes relevant to clinical diagnosis. A robust template-based classification scheme is also developed, but our primary focus is in the discovery of phenotypic signatures and inter-sample relationships in an FC data collection. This collective analysis approach is more efficient and robust since templates describe phenotypic signatures common to cell populations in several samples while ignoring noise and small sample-specific variations. We have applied the template-based scheme to analyze several datasets, including one representing a healthy immune system and one of acute myeloid leukemia (AML) samples. The last task is challenging due to the phenotypic heterogeneity of the several subtypes of AML. However, we identified thirteen immunophenotypes corresponding to subtypes of AML and were able to distinguish acute promyelocytic leukemia (APL) samples with the markers provided. Clinically, this is helpful since APL has a different treatment regimen from other subtypes of AML. Core algorithms used in our data analysis are available in the flowMatch package at www.bioconductor.org. It has been downloaded nearly 6,000 times since 2014.« less

Pieces of the ancient lunar crust - Ages and composition of clasts in consortium breccia 67915

NASA Technical Reports Server (NTRS)

Marti, K.; Jost, D. T.; Aeschlimann, U.; Eberhardt, P.; Geiss, J.; Groegler, N.; Laul, J. C.; Ma, M.-S.; Schmitt, R. A.; Taylor, G. J.

1983-01-01

The composition and chronology of clasts representing three minor lithologies in consortium breccia 67915 are discussed. The lithologies studied are: sodic ferrogabbro, pristine troctolitic anorthosite (67915,26), and granulitic troctolitic anorthosite (67915,67). These lithologies were presumed to represent samples of the ancient lunar crust. The pristine troctolitic anorthosite, a typical member of the pristine anorthosite suite, contains little or no trapped liquid consistent with its two-phase mineralogy. The plagioclase separates have Ar-39-Ar-40 plateau ages of 4.10 + or - 0.06 b.y., and a final rise in the age pattern may represent a 'memory' of the earlier evolution. The granulitic troctolitic anorthosite, which has 13 times larger REE abundances, displays a continuous rise of the Ar-40/Ar-39 ratio. The last 25 percent of the Ar-39 release data establish a minimum age of over 3.5 b.y., but the Pu-244/Nd chronology suggests an age of about 4.3 b.y. The sodic ferrogabbro samples, which appear to be members of the Mg-gabbronorite group of pristine rocks, show large Ar losses but indicate plateaus in the low-temperature data, suggesting a metamorphic event more recently than 260 m.y. ago, a time that is consistent with the North Ray impact event 50 m.y. ago.

Relationship history and relationship attitudes in gay males and lesbians: attachment style and gender differences.

PubMed

Ridge, S R; Feeney, J A

1998-12-01

The objective of the present study was to assess the applicability of attachment theory to the relationships of gay males and lesbians, with particular emphasis on parental relationships, relationship satisfaction, sexual attitudes and 'coming out' as being homosexual. Gay males (n = 77) and lesbians (n = 100) completed questionnaires assessing attachment style, working models of attachment, early relationships with parents and relationship history, status and functioning. A comparison sample of heterosexual participants completed measures of attachment style and relationship history. Relative frequencies of attachment styles were similar for homosexual and heterosexual samples. Contrary to previous research using largely heterosexual respondents, no link between early parenting and attachment style was found. However, homosexual males reported more positive early relationships with mothers than did females. Associations of attachment style with working models, relationship variables and sexual attitudes largely supported those based on heterosexual samples. Gender and attachment style differences were found in reported effects of 'coming out' on relationships with parents. Overall, the results suggest that insecure attachment may not be over-represented in gay and lesbian samples, but that insecurity is associated with less relationship satisfaction and with problems related to the disclosure of sexual orientation. The implications of these findings for research and clinical practice are addressed.

Genetic heterogeneity in primary and relapsed mantle cell lymphomas: Impact of recurrent CARD11 mutations.

PubMed

Wu, Chenglin; de Miranda, Noel Fcc; Chen, Longyun; Wasik, Agata M; Mansouri, Larry; Jurczak, Wojciech; Galazka, Krystyna; Dlugosz-Danecka, Monika; Machaczka, Maciej; Zhang, Huilai; Peng, Roujun; Morin, Ryan D; Rosenquist, Richard; Sander, Birgitta; Pan-Hammarström, Qiang

2016-06-21

The genetic mechanisms underlying disease progression, relapse and therapy resistance in mantle cell lymphoma (MCL) remain largely unknown. Whole-exome sequencing was performed in 27 MCL samples from 13 patients, representing the largest analyzed series of consecutive biopsies obtained at diagnosis and/or relapse for this type of lymphoma. Eighteen genes were found to be recurrently mutated in these samples, including known (ATM, MEF2B and MLL2) and novel mutation targets (S1PR1 and CARD11). CARD11, a scaffold protein required for B-cell receptor (BCR)-induced NF-κB activation, was subsequently screened in an additional 173 MCL samples and mutations were observed in 5.5% of cases. Based on in vitro cell line-based experiments, overexpression of CARD11 mutants were demonstrated to confer resistance to the BCR-inhibitor ibrutinib and NF-κB-inhibitor lenalidomide. Genetic alterations acquired in the relapse samples were found to be largely non-recurrent, in line with the branched evolutionary pattern of clonal evolution observed in most cases. In summary, this study highlights the genetic heterogeneity in MCL, in particular at relapse, and provides for the first time genetic evidence of BCR/NF-κB activation in a subset of MCL.

Investigation of rare and low-frequency variants using high-throughput sequencing with pooled DNA samples

PubMed Central

Wang, Jingwen; Skoog, Tiina; Einarsdottir, Elisabet; Kaartokallio, Tea; Laivuori, Hannele; Grauers, Anna; Gerdhem, Paul; Hytönen, Marjo; Lohi, Hannes; Kere, Juha; Jiao, Hong

2016-01-01

High-throughput sequencing using pooled DNA samples can facilitate genome-wide studies on rare and low-frequency variants in a large population. Some major questions concerning the pooling sequencing strategy are whether rare and low-frequency variants can be detected reliably, and whether estimated minor allele frequencies (MAFs) can represent the actual values obtained from individually genotyped samples. In this study, we evaluated MAF estimates using three variant detection tools with two sets of pooled whole exome sequencing (WES) and one set of pooled whole genome sequencing (WGS) data. Both GATK and Freebayes displayed high sensitivity, specificity and accuracy when detecting rare or low-frequency variants. For the WGS study, 56% of the low-frequency variants in Illumina array have identical MAFs and 26% have one allele difference between sequencing and individual genotyping data. The MAF estimates from WGS correlated well (r = 0.94) with those from Illumina arrays. The MAFs from the pooled WES data also showed high concordance (r = 0.88) with those from the individual genotyping data. In conclusion, the MAFs estimated from pooled DNA sequencing data reflect the MAFs in individually genotyped samples well. The pooling strategy can thus be a rapid and cost-effective approach for the initial screening in large-scale association studies. PMID:27633116

Slaughterhouses Fungal Burden Assessment: A Contribution for the Pursuit of a Better Assessment Strategy

PubMed Central

Viegas, Carla; Faria, Tiago; dos Santos, Mateus; Carolino, Elisabete; Sabino, Raquel; Quintal Gomes, Anita; Viegas, Susana

2016-01-01

In slaughterhouses, the biological risk is present not only from the direct or indirect contact with animal matter, but also from the exposure to bioaerosols. Fungal contamination was already reported from the floors and walls of slaughterhouses. This study intends to assess fungal contamination by cultural and molecular methods in poultry, swine/bovine and large animal slaughterhouses. Air samples were collected through an impaction method, while surface samples were collected by the swabbing method and subjected to further macro- and micro-scopic observations. In addition, we collected air samples using the impinger method in order to perform real-time quantitative PCR (qPCR) amplification of genes from specific fungal species, namely A. flavus, A. fumigatus and A. ochraceus complexes. Poultry and swine/bovine slaughterhouses presented each two sampling sites that surpass the guideline of 150 CFU/m3. Scopulariopsis candida was the most frequently isolated (59.5%) in poultry slaughterhouse air; Cladosporium sp. (45.7%) in the swine/bovine slaughterhouse; and Penicillium sp. (80.8%) in the large animal slaughterhouse. Molecular tools successfully amplified DNA from the A. fumigatus complex in six sampling sites where the presence of this fungal species was not identified by conventional methods. This study besides suggesting the indicators that are representative of harmful fungal contamination, also indicates a strategy as a protocol to ensure a proper characterization of fungal occupational exposure. PMID:27005642

Use of porosity to estimate hydraulic properties of volcanic tuffs

USGS Publications Warehouse

Flint, L.E.; Selker, J.S.

2003-01-01

Correlations of hydraulic properties with easily measured physical properties are useful for purposes of site characterization in heterogeneous sites. Approximately 600 samples of volcanic rocks from Yucca Mountain, Nevada, representing lithologies with a large range of hydraulic properties, were analyzed to develop correlations of effective porosity with saturated hydraulic conductivity and moisture-retention curve-fit parameters that relate to lithologies of varying depositional history and alteration processes. Effective porosity, ??e, defined as the porosity calculated using drying at a relative humidity of -70 MPa, is used in a generalized Kozeny-Carman equation to predict saturated hydraulic conductivity, Ks = b??en, where b and n are constants. The entire dataset has an R2 of 0.36. When samples are grouped according to general lithology, correlations result in an R2 of 0.71 for the crystallized/vitric samples, 0.24 for samples with mineral alteration, and 0.34 for samples with microfractures, thus increasing the predictive capability over that of the total dataset. Published by Elsevier Science Ltd.

Reef-associated crustacean fauna: biodiversity estimates using semi-quantitative sampling and DNA barcoding

NASA Astrophysics Data System (ADS)

Plaisance, L.; Knowlton, N.; Paulay, G.; Meyer, C.

2009-12-01

The cryptofauna associated with coral reefs accounts for a major part of the biodiversity in these ecosystems but has been largely overlooked in biodiversity estimates because the organisms are hard to collect and identify. We combine a semi-quantitative sampling design and a DNA barcoding approach to provide metrics for the diversity of reef-associated crustacean. Twenty-two similar-sized dead heads of Pocillopora were sampled at 10 m depth from five central Pacific Ocean localities (four atolls in the Northern Line Islands and in Moorea, French Polynesia). All crustaceans were removed, and partial cytochrome oxidase subunit I was sequenced from 403 individuals, yielding 135 distinct taxa using a species-level criterion of 5% similarity. Most crustacean species were rare; 44% of the OTUs were represented by a single individual, and an additional 33% were represented by several specimens found only in one of the five localities. The Northern Line Islands and Moorea shared only 11 OTUs. Total numbers estimated by species richness statistics (Chao1 and ACE) suggest at least 90 species of crustaceans in Moorea and 150 in the Northern Line Islands for this habitat type. However, rarefaction curves for each region failed to approach an asymptote, and Chao1 and ACE estimators did not stabilize after sampling eight heads in Moorea, so even these diversity figures are underestimates. Nevertheless, even this modest sampling effort from a very limited habitat resulted in surprisingly high species numbers.

Moving beyond the van Krevelen Diagram: A New Stoichiometric Approach for Compound Classification in Organisms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rivas-Ubach, Albert; Liu, Yina; Bianchi, Thomas S.

van Krevelen diagrams (O:C vs H:C ratios of elemental formulas) have been widely used in studies to obtain an estimation of the main compound categories present in environmental samples. However, the limits defining a specific compound category based solely on O:C and H:C ratios of elemental formulas have never been accurately listed or proposed to classify metabolites in biological samples. Furthermore, while O:C vs. H:C ratios of elemental formulas can provide an overview of the compound categories, such classification is inefficient because of the large overlap among different compound categories along both axes. We propose a more accurate compound classificationmore » for biological samples analyzed by high-resolution mass spectrometry-based on an assessment of the C:H:O:N:P stoichiometric ratios of over 130,000 elemental formulas of compounds classified in 6 main categories: lipids, peptides, amino-sugars, carbohydrates, nucleotides and phytochemical compounds (oxy-aromatic compounds). Our multidimensional stoichiometric compound classification (MSCC) constraints showed a highly accurate categorization of elemental formulas to the main compound categories in biological samples with over 98% of accuracy representing a substantial improvement over any classification based on the classic van Krevelen diagram. This method represents a significant step forward in environmental research, especially ecological stoichiometry and eco-metabolomics studies, by providing a novel and robust tool to further our understanding the ecosystem structure and function through the chemical characterization of different biological samples.« less

Reliable and fast quantitative analysis of active ingredient in pharmaceutical suspension using Raman spectroscopy.

PubMed

Park, Seok Chan; Kim, Minjung; Noh, Jaegeun; Chung, Hoeil; Woo, Youngah; Lee, Jonghwa; Kemper, Mark S

2007-06-12

The concentration of acetaminophen in a turbid pharmaceutical suspension has been measured successfully using Raman spectroscopy. The spectrometer was equipped with a large spot probe which enabled the coverage of a representative area during sampling. This wide area illumination (WAI) scheme (coverage area 28.3 mm2) for Raman data collection proved to be more reliable for the compositional determination of these pharmaceutical suspensions, especially when the samples were turbid. The reproducibility of measurement using the WAI scheme was compared to that of using a conventional small-spot scheme which employed a much smaller illumination area (about 100 microm spot size). A layer of isobutyric anhydride was placed in front of the sample vials to correct the variation in the Raman intensity due to the fluctuation of laser power. Corrections were accomplished using the isolated carbonyl band of isobutyric anhydride. The acetaminophen concentrations of prediction samples were accurately estimated using a partial least squares (PLS) calibration model. The prediction accuracy was maintained even with changes in laser power. It was noted that the prediction performance was somewhat degraded for turbid suspensions with high acetaminophen contents. When comparing the results of reproducibility obtained with the WAI scheme and those obtained using the conventional scheme, it was concluded that the quantitative determination of the active pharmaceutical ingredient (API) in turbid suspensions is much improved when employing a larger laser coverage area. This is presumably due to the improvement in representative sampling.

Formation and distribution of fragments in the spontaneous fission of 240 Pu

DOE PAGES

Sadhukhan, Jhilam; Zhang, Chunli; Nazarewicz, Witold; ...

2017-12-18

We use the stochastic Langevin framework to simulate the nuclear evolution after the system tunnels through the multidimensional potential barrier. For a representative sample of different initial configurations along the outer turning-point line, we define effective fission paths by computing a large number of Langevin trajectories. We extract the relative contribution of each such path to the fragment distribution. We then use nucleon localization functions along effective fission pathways to analyze the characteristics of prefragments at prescission configurations.

New River Dam Foundation Report. Gila River Basin: Phoenix, Arizona and Vicinity (Including New River).

DTIC Science & Technology

1985-10-01

further downstream before merging with the Agua Fria River. 6 Site Geology 2.08 The geological formations present within the project area consist...sampling and in- situ density testing using the sand displacement 11 or large-scale water displacement method. Dozer trenches TT82-1 and TT82-6 were excavated...underlying the valley or may, due to its pervasiveness, represent an in situ weathering product of the buried bedrock. 4.18 Because of the magnitude

Climate of the Kennedy Space Center and vicinity

NASA Technical Reports Server (NTRS)

Mailander, Joseph L.

1990-01-01

Climate plays a large role in determining the biota of a region. Summary data are presented for climate variables of ecological importance including precipitation, temperature, evapotranspiration, wind, isolation, lightning, and humidity. The John F. Kennedy Space Center, Cape Canaveral Air Force Station, and surrounding area are sampled intensively for climatic conditions; data are presented for the barrier island, Merritt Island, and the mainland, which represents the range of conditions in the local area. Climatic figures, database listings, and historic data (pre-1931) are presented in the appendix.

Clinical presentation of hyperthyroidism in a large representative sample of outpatients in France: relationships with age, aetiology and hormonal parameters.

PubMed

Goichot, B; Caron, Ph; Landron, F; Bouée, S

2016-03-01

Signs and symptoms of thyrotoxicosis are not specific, and thyroid function tests are frequently prescribed to recognize such thyroid dysfunction. Ultrasensitive assays of thyroid-stimulating hormone (TSH) allow early diagnosis and identification of mild hyperthyroidism (generally designed as 'subclinical'). The aim of this study was to re-evaluate the clinical picture of thyrotoxicosis in the context of the current large utilization of ultrasensitive TSH assays. Prospective descriptive cohort. Clinical presentation of 1572 patients with a recent (<3 months) diagnosis of thyrotoxicosis recruited by a large representative sample of 263 French endocrinologists was studied using two questionnaires (one at inclusion and the second after 3 months) concerning symptoms, hormonal evaluation and treatment. A total of 1240 (78·9%) patients were women, mean age 48 ± 17 years. Subclinical hyperthyroidism (SCHT) was present in 86 patients (10·4%). Symptoms of thyrotoxicosis were in decreasing frequency order: palpitations, weakness, heat-related signs and disturbed sleep. A total of 64·9% of patients had lost weight. Signs and symptoms were more frequent in Graves' disease, in young patients, and were partially related to biochemical severity. Symptoms were less frequent in elderly patients except for cardiac manifestations (atrial fibrillation). Most patients with SCHT had one or several signs or symptoms of thyrotoxicosis. This study confirms that elderly patients have less symptoms of thyrotoxicosis than younger subjects but are at increased risk of cardiac complications. Our results show that most patients with 'subclinical' HT have in fact signs or symptoms of thyrotoxicosis. © 2015 John Wiley & Sons Ltd.

Spectral analysis of tissues from patients with cancer using a portable spectroscopic diagnostic ratiometer unit

NASA Astrophysics Data System (ADS)

Sordillo, Laura A.; Pu, Yang; Sordillo, Peter P.; Budansky, Yury; Alfano, R. R.

2014-05-01

Spectral profiles of tissues from patients with breast carcinoma, malignant carcinoid and non-small cell lung carcinoma were acquired using native fluorescence spectroscopy. A novel spectroscopic ratiometer device (S3-LED) with selective excitation wavelengths at 280 nm and 335 nm was used to produce the emission spectra of the key biomolecules, tryptophan and NADH, in the tissue samples. In each of the samples, analysis of emission intensity peaks from biomolecules showed increased 340 nm/440 nm and 340 nm/460 nm ratios in the malignant samples compared to their paired normal samples. This most likely represented increased tryptophan to NADH ratios in the malignant tissue samples compared to their paired normal samples. Among the non-small cell lung carcinoma and breast carcinomas, it appeared that tumors of very large size or poor differentiation had an even greater increase in the 340 nm/440 nm and 340 nm/460 nm ratios. In the samples of malignant carcinoid, which is known to be a highly metabolically active tumor, a marked increase in these ratios was also seen.

The Relationship of Self-reported Executive Functioning to Suicide Ideation and Attempts: Findings from a Large U.S.-based Online Sample.

PubMed

Saffer, Boaz Y; Klonsky, E David

2017-01-01

An increasing number of studies demonstrate that individuals with a history of suicidality exhibit impaired executive functioning abilities. The current study examines whether these differences are linked to suicidal thoughts or suicidal acts-a crucial distinction given that most people who think about suicide will not act on their thoughts. A large online sample of U.S. participants with a history of suicide ideation (n = 197), suicide attempts (n = 166), and no suicidality (n = 180) completed self-report measures assessing executive functioning, suicide ideation and attempts; in addition, depression, self-efficacy, and history of drug abuse and brain injury were assessed as potential covariates. Individuals with recent suicide attempts reported significantly worse executive functioning than ideators. This difference was not accounted for by depression, self-efficacy, history of drug abuse or brain injury. Self-reported executive functioning may represent an important short-term risk factor for suicide attempts.

Risk of co-occuring psychopathology: testing a prediction of expectancy theory.

PubMed

Capron, Daniel W; Norr, Aaron M; Schmidt, Norman B

2013-01-01

Despite the high impact of anxiety sensitivity (AS; a fear of anxiety related sensations) research, almost no research attention has been paid to its parent theory, Reiss' expectancy theory (ET). ET has gone largely unexamined to this point, including the prediction that AS is a better predictor of number of fears than current anxiety. To test Reiss' prediction, we used a large (N = 317) clinical sample of anxiety outpatients. Specifically, we examined whether elevated AS predicted number of comorbid anxiety and non-anxiety disorder diagnoses in this sample. Consistent with ET, findings indicated that AS predicted number of comorbid anxiety disorder diagnoses above and beyond current anxiety symptoms. Also, AS did not predict the number of comorbid non-anxiety diagnoses when current anxiety symptoms were accounted for. These findings represent an important examination of a prediction of Reiss' ET and are consistent with the idea that AS may be a useful transdiagnostic treatment target. Copyright © 2012 Elsevier Ltd. All rights reserved.

A Comparison of Techniques for Scheduling Earth-Observing Satellites

NASA Technical Reports Server (NTRS)

Globus, Al; Crawford, James; Lohn, Jason; Pryor, Anna

2004-01-01

Scheduling observations by coordinated fleets of Earth Observing Satellites (EOS) involves large search spaces, complex constraints and poorly understood bottlenecks, conditions where evolutionary and related algorithms are often effective. However, there are many such algorithms and the best one to use is not clear. Here we compare multiple variants of the genetic algorithm: stochastic hill climbing, simulated annealing, squeaky wheel optimization and iterated sampling on ten realistically-sized EOS scheduling problems. Schedules are represented by a permutation (non-temperal ordering) of the observation requests. A simple deterministic scheduler assigns times and resources to each observation request in the order indicated by the permutation, discarding those that violate the constraints created by previously scheduled observations. Simulated annealing performs best. Random mutation outperform a more 'intelligent' mutator. Furthermore, the best mutator, by a small margin, was a novel approach we call temperature dependent random sampling that makes large changes in the early stages of evolution and smaller changes towards the end of search.

On the Representativeness of Behavior Observation Samples in Classrooms

ERIC Educational Resources Information Center

Tiger, Jeffrey H.; Miller, Sarah J.; Mevers, Joanna Lomas; Mintz, Joslyn Cynkus; Scheithauer, Mindy C.; Alvarez, Jessica

2013-01-01

School consultants who rely on direct observation typically conduct observational samples (e.g., 1 30-min observation per day) with the hopes that the sample is representative of performance during the remainder of the day, but the representativeness of these samples is unclear. In the current study, we recorded the problem behavior of 3 referred…

Latin American Study of Nutrition and Health (ELANS): rationale and study design.

PubMed

Fisberg, M; Kovalskys, I; Gómez, G; Rigotti, A; Cortés, L Y; Herrera-Cuenca, M; Yépez, M C; Pareja, R G; Guajardo, V; Zimberg, I Z; Chiavegatto Filho, A D P; Pratt, M; Koletzko, B; Tucker, K L

2016-01-30

Obesity is growing at an alarming rate in Latin America. Lifestyle behaviours such as physical activity and dietary intake have been largely associated with obesity in many countries; however studies that combine nutrition and physical activity assessment in representative samples of Latin American countries are lacking. The aim of this study is to present the design rationale of the Latin American Study of Nutrition and Health/Estudio Latinoamericano de Nutrición y Salud (ELANS) with a particular focus on its quality control procedures and recruitment processes. The ELANS is a multicenter cross-sectional nutrition and health surveillance study of a nationally representative sample of urban populations from eight Latin American countries (Argentina, Brazil, Chile, Colombia, Costa Rica, Ecuador, Perú and Venezuela). A standard study protocol was designed to evaluate the nutritional intakes, physical activity levels, and anthropometric measurements of 9000 enrolled participants. The study was based on a complex, multistage sample design and the sample was stratified by gender, age (15 to 65 years old) and socioeconomic level. A small-scale pilot study was performed in each country to test the procedures and tools. This study will provide valuable information and a unique dataset regarding Latin America that will enable cross-country comparisons of nutritional statuses that focus on energy and macro- and micronutrient intakes, food patterns, and energy expenditure. Clinical Trials NCT02226627.

Comparing two basic subtypes in OCD across three large community samples: a pure compulsive versus a mixed obsessive-compulsive subtype.

PubMed

Rodgers, Stephanie; Ajdacic-Gross, Vladeta; Kawohl, Wolfram; Müller, Mario; Rössler, Wulf; Hengartner, Michael P; Castelao, Enrique; Vandeleur, Caroline; Angst, Jules; Preisig, Martin

2015-12-01

Due to its heterogeneous phenomenology, obsessive-compulsive disorder (OCD) has been subtyped. However, these subtypes are not mutually exclusive. This study presents an alternative subtyping approach by deriving non-overlapping OCD subtypes. A pure compulsive and a mixed obsessive-compulsive subtype (including subjects manifesting obsessions with/without compulsions) were analyzed with respect to a broad pattern of psychosocial risk factors and comorbid syndromes/diagnoses in three representative Swiss community samples: the Zurich Study (n = 591), the ZInEP sample (n = 1500), and the PsyCoLaus sample (n = 3720). A selection of comorbidities was examined in a pooled database. Odds ratios were derived from logistic regressions and, in the analysis of pooled data, multilevel models. The pure compulsive subtype showed a lower age of onset and was characterized by few associations with psychosocial risk factors. The higher social popularity of the pure compulsive subjects and their families was remarkable. Comorbidities within the pure compulsive subtype were mainly restricted to phobias. In contrast, the mixed obsessive-compulsive subtype had a higher prevalence and was associated with various childhood adversities, more familial burden, and numerous comorbid disorders, including disorders characterized by high impulsivity. The current comparison study across three representative community surveys presented two basic, distinct OCD subtypes associated with differing psychosocial impairment. Such highly specific subtypes offer the opportunity to learn about pathophysiological mechanisms specifically involved in OCD.

No evidence of extraterrestrial noble metal and helium anomalies at Marinoan glacial termination

NASA Astrophysics Data System (ADS)

Peucker-Ehrenbrink, Bernhard; Waters, Christine A.; Kurz, Mark D.; Hoffman, Paul F.

2016-03-01

High concentrations of extraterrestrial iridium have been reported in terminal Sturtian and Marinoan glacial marine sediments and are used to argue for long (likely 3-12 Myr) durations of these Cryogenian glaciations. Reanalysis of the Marinoan sedimentary rocks used in the original study, supplemented by sedimentary rocks from additional terminal Marinoan sections, however, does not confirm the initial report. New platinum group element concentrations, and 187Os/188Os and 3He/4He signatures are consistent with crustal origin and minimal extraterrestrial contributions. The discrepancy is likely caused by different sample masses used in the two studies, with this study being based on much larger samples that better capture the stochastic distribution of extraterrestrial particles in marine sediments. Strong enrichment of redox-sensitive elements, particularly rhenium, up-section in the basal postglacial cap carbonates, may indicate a return to more fully oxygenated seawater in the aftermath of the Marinoan snowball earth. Sections dominated by hydrogenous osmium indicate increasing submarine hydrothermal sources and/or continental inputs that are increasingly dominated by young mantle-derived rocks after deglaciation. Sedimentation rate estimates for the basal cap carbonates yield surprisingly slow rates of a few centimeters per thousand years. This study highlights the importance of using sedimentary rock samples that represent sufficiently large area-time products to properly sample extraterrestrial particles representatively, and demonstrates the value of using multiple tracers of extraterrestrial matter.

Previously unknown and highly divergent ssDNA viruses populate the oceans.

PubMed

Labonté, Jessica M; Suttle, Curtis A

2013-11-01

Single-stranded DNA (ssDNA) viruses are economically important pathogens of plants and animals, and are widespread in oceans; yet, the diversity and evolutionary relationships among marine ssDNA viruses remain largely unknown. Here we present the results from a metagenomic study of composite samples from temperate (Saanich Inlet, 11 samples; Strait of Georgia, 85 samples) and subtropical (46 samples, Gulf of Mexico) seawater. Most sequences (84%) had no evident similarity to sequenced viruses. In total, 608 putative complete genomes of ssDNA viruses were assembled, almost doubling the number of ssDNA viral genomes in databases. These comprised 129 genetically distinct groups, each represented by at least one complete genome that had no recognizable similarity to each other or to other virus sequences. Given that the seven recognized families of ssDNA viruses have considerable sequence homology within them, this suggests that many of these genetic groups may represent new viral families. Moreover, nearly 70% of the sequences were similar to one of these genomes, indicating that most of the sequences could be assigned to a genetically distinct group. Most sequences fell within 11 well-defined gene groups, each sharing a common gene. Some of these encoded putative replication and coat proteins that had similarity to sequences from viruses infecting eukaryotes, suggesting that these were likely from viruses infecting eukaryotic phytoplankton and zooplankton.

Insomnia, psychiatric disorders and suicidal ideation in a National Representative Sample of active Canadian Forces members.

PubMed

Richardson, J D; Thompson, A; King, L; Corbett, B; Shnaider, P; St Cyr, K; Nelson, C; Sareen, J; Elhai, J; Zamorski, M

2017-06-06

Past research on the association between insomnia and suicidal ideation (SI) has produced mixed findings. The current study explored the relationship between insomnia, SI, and past-year mental health status among a large Canadian Forces (CF) sample. Data was obtained from the 2013 Canadian Forces Mental Health Survey (CFMHS), and included a large representative sample of Canadian Regular Forces personnel (N = 6700). A series of univariate logistic regressions were conducted to test individual associations between past-year mental health status, insomnia, and potential confounds and SI. Mental health status included three groups: 0, 1, or two or more probable diagnoses of posttraumatic stress disorder (PTSD), major depressive disorder (MDD), generalized anxiety disorder (GAD), panic disorder (PD) and alcohol abuse/dependence. Stepwise multivariate logistic regression was used to assess the relationship between insomnia and SI with mental health status as a moderator. 40.8% of respondents reported experiencing insomnia. Both insomnia and number of mental health conditions incrementally increased the risk of SI. However, past-year mental health status was a significant moderator of this relationship, such that for CF personnel with either no (AOR = 1.61, 1.37-1.89) or only one past-year mental health condition (AOR = 1.39, 1.12-1.73), an incremental increase in insomnia was associated with an increased likelihood of SI. However, in personnel with two or more past-year mental health disorders, insomnia was no longer significantly associated with SI (AOR = 1.04, 0.81-1.33). Insomnia significantly increased the odds of SI, but only among individuals with no or one mental health condition. Findings highlight the importance of assessing insomnia among CF members in order to further suicide prevention efforts.

Psychometric Properties of the Problematic Internet Use Questionnaire Short-Form (PIUQ-SF-6) in a Nationally Representative Sample of Adolescents.

PubMed

Demetrovics, Zsolt; Király, Orsolya; Koronczai, Beatrix; Griffiths, Mark D; Nagygyörgy, Katalin; Elekes, Zsuzsanna; Tamás, Domokos; Kun, Bernadette; Kökönyei, Gyöngyi; Urbán, Róbert

2016-01-01

Despite the large number of measurement tools developed to assess problematic Internet use, numerous studies use measures with only modest investigation into their psychometric properties. The goal of the present study was to validate the short (6-item) version of the Problematic Internet Use Questionnaire (PIUQ) on a nationally representative adolescent sample (n = 5,005; mean age 16.4 years, SD = 0.87) and to determine a statistically established cut-off value. Data were collected within the framework of the European School Survey Project on Alcohol and Other Drugs project. Results showed an acceptable fit of the original three-factor structure to the data. In addition, a MIMIC model was carried out to justify the need for three distinct factors. The sample was divided into users at-risk of problematic Internet use and those with no-risk using a latent profile analysis. Two latent classes were obtained with 14.4% of adolescents belonging to the at-risk group. Concurrent and convergent validity were tested by comparing the two groups across a number of variables (i.e., time spent online, academic achievement, self-esteem, depressive symptoms, and preferred online activities). Using the at-risk latent profile analysis class as the gold standard, a cut-off value of 15 (out of 30) was suggested based on sensitivity and specificity analyses. In conclusion, the brief version of the (6-item) PIUQ also appears to be an appropriate measure to differentiate between Internet users at risk of developing problematic Internet use and those not at risk. Furthermore, due to its brevity, the shortened PIUQ is advantageous to utilize within large-scale surveys assessing many different behaviors and/or constructs by reducing the overall number of survey questions, and as a consequence, likely increasing completion rates.

Source apportionment of lead in the blood of women of reproductive age living near tailings in Taxco, Guerrero, Mexico: An isotopic study.

PubMed

Vázquez Bahéna, Analine Berenice; Talavera Mendoza, Oscar; Moreno Godínez, Ma Elena; Salgado Souto, Sergio Adrián; Ruiz, Joaquín; Huerta Beristain, Gerardo

2017-04-01

The concentration and isotopic composition of lead in the blood of forty seven women of reproductive age (15-45y) exposed to multiple sources in two rural communities of the mining region of Taxco, Guerrero in southern Mexico were determined in order to identify specific contributing sources and their apportionment and to trace probable ingestion pathways. Our data indicate that >36% of the studied women have blood lead concentrations above 10μgdL -1 and up to 87% above 5μgdL -1 . Tailings contain between 2128 and 5988mgkg -1 of lead and represent the most conspicuous source in the area. Lead contents in indoor dust are largely variable (21.7-987mgkg -1 ) but only 15% of samples are above the Mexican Regulatory Guideline for urban soils (400mgkg -1 ). By contrast, 85% of glazed containers (range: 0.026-68.6mgkg -1 ) used for cooking and food storage are above the maximum 2mgL -1 of soluble lead established in the Mexican Guideline. The isotopic composition indicates that lead in the blood of 95% of the studied women can be modeled in terms of a mixing system between local ores (and derivatives), glazed pottery and Morelos bedrock, end-members, with the two former being largely the most important contributors. Only one sample shows influence of indoor paints. Indoor dust is dominated by ores and derivatives but some samples show evidence of contribution from a less radiogenic source very likely represented by interior paints. This study supports the application of lead isotopic ratios to identify potential sources and their apportionment in humans exposed to multiple sources of lead from both, natural and anthropogenic origin. Copyright © 2017 Elsevier B.V. All rights reserved.

The Sex, Age, and Me study: recruitment and sampling for a large mixed-methods study of sexual health and relationships in an older Australian population.

PubMed

Lyons, Anthony; Heywood, Wendy; Fileborn, Bianca; Minichiello, Victor; Barrett, Catherine; Brown, Graham; Hinchliff, Sharron; Malta, Sue; Crameri, Pauline

2017-09-01

Older people are often excluded from large studies of sexual health, as it is assumed that they are not having sex or are reluctant to talk about sensitive topics and are therefore difficult to recruit. We outline the sampling and recruitment strategies from a recent study on sexual health and relationships among older people. Sex, Age and Me was a nationwide Australian study that examined sexual health, relationship patterns, safer-sex practices and STI knowledge of Australians aged 60 years and over. The study used a mixed-methods approach to establish baseline levels of knowledge and to develop deeper insights into older adult's understandings and practices relating to sexual health. Data collection took place in 2015, with 2137 participants completing a quantitative survey and 53 participating in one-on-one semi-structured interviews. As the feasibility of this type of study has been largely untested until now, we provide detailed information on the study's recruitment strategies and methods. We also compare key characteristics of our sample with national estimates to assess its degree of representativeness. This study provides evidence to challenge the assumptions that older people will not take part in sexual health-related research and details a novel and successful way to recruit participants in this area.

Culture modifies expectations of kinship and sex-biased dispersal patterns: a case study of patrilineality and patrilocality in tribal Yemen.

PubMed

Raaum, Ryan L; Al-Meeri, Ali; Mulligan, Connie J

2013-04-01

Studies of the impact of post-marital residence patterns on the distribution of genetic variation within populations have returned conflicting results. These studies have generally examined genetic diversity within and between groups with different post-marriage residence patterns. Here, we directly examine Y chromosome microsatellite variation in individuals carrying a chromosome in the same Y haplogroup. We analyze Y chromosome data from two samples of Yemeni males: a sample representing the entire country and a sample from a large highland village. Our results support a normative patrilocality in highland Yemeni tribal populations, but also suggest that patrilocality is violated often enough to break down the expected correlation of genetic and geographic distance. We propose that a great deal of variation in male dispersal distance distributions is subsumed under the "patrilocal" label and that few human societies are likely to realize the idealized male dispersal distribution expected under strict patrilocality. In addition, we found almost no specific correspondence between social kinship and genetic patriline at the level of the clan (large, extended patrilineal kinship group) within a large, highland Yemeni village. We discuss ethnographic accounts that offer several cultural practices that explain exceptions to patrilocality and means by which social kinship and genetic patriline may become disentangled. Copyright © 2013 Wiley Periodicals, Inc.

A foodborne outbreak of Salmonella infection due to overproduction of egg-containing foods for a festival.

PubMed Central

Camps, N.; Domínguez, A.; Company, M.; Pérez, M.; Pardos, J.; Llobet, T.; Usera, M. A.; Salleras, L.

2005-01-01

A large outbreak of gastroenteritis occurred in Catalonia in June 2002 with 1435 cases and 117 hospitalizations. Consumption of a hard pastry with vanilla cream was strongly associated with illness. Stool samples from cases and food-handlers were analysed. The premises of the food manufacturer were inspected and food samples were taken for microbiological analysis. Salmonella serotype Enteriditis was isolated from 154 cases, three food-handlers and nine food samples. Outbreak-associated strains showed a coincident phage type, antibiotype and pulse-field gel electrophoresis pattern. Inadequate handling of foods containing eggs occurred because the establishment exceeded its safe food production capacity to meet demand for the pastry, which was consumed on the day of a traditional festival. Excessive production of foods for holidays or special events represents a potential public health threat. PMID:16181500

Elastic Parameters of West Bohemian Granites under Hydrostatic Pressure

NASA Astrophysics Data System (ADS)

Pros, Z.; Lokajíček, T.; Přikryl, R.; Špičák, A.; Vajdová, V.; Klíma, K.

The West Bohemian seismoactive region is situated near the contact of the Moldanu bian, Bohemian and Saxothuringian units in which a large volume is occupied by granitoid massifs. The spatial distribution of P-wave velocities and the rock fabric of five representative samples from these massifs were studied. The P-wave velocities were measured on spherical samples in 132 independent directions under hydrostatic pressure up to 400 MPa, using the pulse-transmission method. The pressure of 400 MPa corresponds to a depth of about 15 km in the area under study. The changes of P-wave velocity were correlated with the preferred orientations of the main rock fabric elements, i.e., rock forming minerals and microcracks. The values of the P-wave velocity from laboratory measurements on granite samples fit the velocity model used by seismologists in the West Bohemian seismoactive region.

Antarctic Marine Biodiversity – What Do We Know About the Distribution of Life in the Southern Ocean?

PubMed Central

Griffiths, Huw J.

2010-01-01

The remote and hostile Southern Ocean is home to a diverse and rich community of life that thrives in an environment dominated by glaciations and strong currents. Marine biological studies in the region date back to the nineteenth century, but despite this long history of research, relatively little is known about the complex interactions between the highly seasonal physical environment and the species that inhabit the Southern Ocean. Oceanographically, the Southern Ocean is a major driver of global ocean circulation and plays a vital role in interacting with the deep water circulation in each of the Pacific, Atlantic, and Indian oceans. The Census of Antarctic Marine Life and the Scientific Committee on Antarctic Research Marine Biodiversity Information Network (SCAR-MarBIN) have strived to coordinate and unify the available scientific expertise and biodiversity data to improve our understanding of Southern Ocean biodiversity. Taxonomic lists for all marine species have been compiled to form the Register of Antarctic Marine Species, which currently includes over 8,200 species. SCAR-MarBIN has brought together over 1 million distribution records for Southern Ocean species, forming a baseline against which future change can be judged. The sample locations and numbers of known species from different regions were mapped and the depth distributions of benthic samples plotted. Our knowledge of the biodiversity of the Southern Ocean is largely determined by the relative inaccessibility of the region. Benthic sampling is largely restricted to the shelf; little is known about the fauna of the deep sea. The location of scientific bases heavily influences the distribution pattern of sample and observation data, and the logistical supply routes are the focus of much of the at-sea and pelagic work. Taxa such as mollusks and echinoderms are well represented within existing datasets with high numbers of georeferenced records. Other taxa, including the species-rich nematodes, are represented by just a handful of digital records. PMID:20689841

Crowdsourcing Disease Biomarker Discovery Research: The IP4IC Study.

PubMed

Chancellor, Michael B; Bartolone, Sarah N; Veerecke, Andrew; Lamb, Laura E

2018-05-01

Biomarker discovery is limited by readily assessable, cost efficient human samples available in large numbers that represent the entire heterogeneity of the disease. We developed a novel, active participation crowdsourcing method to determine BP-RS (Bladder Permeability Defect Risk Score). It is based on noninvasive urinary cytokines to discriminate patients with interstitial cystitis/bladder pain syndrome who had Hunner lesions from controls and patients with interstitial cystitis/bladder pain syndrome but without Hunner lesions. We performed a national crowdsourcing study in cooperation with the Interstitial Cystitis Association. Patients answered demographic, symptom severity and urinary frequency questionnaires on a HIPAA (Health Insurance Portability and Accountability Act) compliant website. Urine samples were collected at home, stabilized with a preservative and sent to Beaumont Hospital for analysis. The expression of 3 urinary cytokines was used in a machine learning algorithm to develop BP-RS. The IP4IC study collected a total of 448 urine samples, representing 153 patients (147 females and 6 males) with interstitial cystitis/bladder pain syndrome, of whom 54 (50 females and 4 males) had Hunner lesions. A total of 159 female and 136 male controls also participated, who were age matched. A defined BP-RS was calculated to predict interstitial cystitis/bladder pain syndrome with Hunner lesions or a bladder permeability defect etiology with 89% validity. In this novel participation crowdsourcing study we obtained a large number of urine samples from 46 states, which were collected at home, shipped and stored at room temperature. Using a machine learning algorithm we developed BP-RS to quantify the risk of interstitial cystitis/bladder pain syndrome with Hunner lesions, which is indicative of a bladder permeability defect etiology. To our knowledge BP-RS is the first validated urine biomarker assay for interstitial cystitis/bladder pain syndrome and one of the first biomarker assays to be developed using crowdsourcing. Copyright © 2018 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Members of the Candidate Phyla Radiation are functionally differentiated by carbon and nitrogen cycling capabilities.

NASA Astrophysics Data System (ADS)

Danczak, R.; Johnston, M.; Kenah, C.; Slattery, M.; Wrighton, K. C.; Wilkins, M.

2017-12-01

The Candidate Phyla Radiation (CPR) is a recently described expansion of the tree of life that represents more than 15% of all bacterial diversity and putatively contains over 70 different phyla. Despite this broad phylogenetic variation, these microorganisms often feature limited functional diversity, with members generally characterized as obligate fermenters. Additionally, much of the data describing CPR phyla has been generated from a limited number of environments, constraining our knowledge of their functional roles and biogeographical distribution. To better understand subsurface CPR microorganisms, we sampled four groundwater wells over two years across three Ohio counties. Samples were analyzed using 16S rRNA gene amplicon and shotgun metagenomic sequencing. Amplicon results indicated that CPR members comprised 2-20% of the microbial communities, with relative abundances stable through time in Athens and Greene county samples but dynamic in Licking county groundwater. Shotgun metagenomic analyses generated 71 putative CPR genomes, representing roughly 32 known phyla and potentially two new phyla, Candidatus Brownbacteria and Candidatus Hugbacteria. While these genomes largely mirrored typical CPR metabolism, some features were previously uncharacterized. For instance, a nirK-encoded nitrite reductase was found in four of our Parcubacteria genomes and multiple CPR genomes from other studies, indicating a possibly undescribed role for these microorganisms in denitrification. Additionally, glycoside hydrolase (GH) family profiles for our genomes and over 2000 other CPR genomes were analyzed to characterize their carbon processing potential. Although common trends were present throughout the radiation, differences highlighted mechanisms that may allow microorganisms across the CPR to occupy various subsurface niches. For example, members of the Microgenomates superphylum appear to potentially degrade a wider range of carbon substrates than other CPR phyla. The CPR appear to be distributed across a range of groundwater systems and often constitute a large fraction of the microbial population. Further sampling of such environments will resolve this phylogenetically broad radiation at finer taxonomic levels and will likely solidify functional differences between phyla.

Bacterial diversity of floor drain biofilms and drain waters in a Listeria monocytogenes contaminated food processing environment.

PubMed

Dzieciol, Monika; Schornsteiner, Elisa; Muhterem-Uyar, Meryem; Stessl, Beatrix; Wagner, Martin; Schmitz-Esser, Stephan

2016-04-16

Sanitation protocols are applied on a daily basis in food processing facilities to prevent the risk of cross-contamination with spoilage organisms. Floor drain water serves along with product-associated samples (slicer dust, brine or cheese smear) as an important hygiene indicator in monitoring Listeria monocytogenes in food processing facilities. Microbial communities of floor drains are representative for each processing area and are influenced to a large degree by food residues, liquid effluents and washing water. The microbial communities of drain water are steadily changing, whereas drain biofilms provide more stable niches. Bacterial communities of four floor drains were characterized using 16S rRNA gene pyrosequencing to better understand the composition and exchange of drain water and drain biofilm communities. Furthermore, the L. monocytogenes contamination status of each floor drain was determined by applying cultivation-independent real-time PCR quantification and cultivation-dependent detection according to ISO11290-1. Pyrosequencing of 16S rRNA genes of drain water and drain biofilm bacterial communities yielded 50,611 reads, which were clustered into 641 operational taxonomic units (OTUs), affiliated to 16 phyla dominated by Proteobacteria, Firmicutes and Bacteroidetes. The most abundant OTUs represented either product- (Lactococcus lactis) or fermentation- and food spoilage-associated phylotypes (Pseudomonas mucidolens, Pseudomonas fragi, Leuconostoc citreum, and Acetobacter tropicalis). The microbial communities in DW and DB samples were distinct in each sample type and throughout the whole processing plant, indicating the presence of indigenous specific microbial communities in each processing compartment. The microbiota of drain biofilms was largely different from the microbiota of the drain water. A sampling approach based on drain water alone may thus only provide reliable information on planktonic bacterial cells but might not allow conclusions on the bacterial composition of the microbiota in biofilms. Copyright © 2016. Published by Elsevier B.V.

Investigating sex differences in psychological predictors of snack intake among a large representative sample.

PubMed

Adriaanse, Marieke A; Evers, Catharine; Verhoeven, Aukje A C; de Ridder, Denise T D

2016-03-01

It is often assumed that there are substantial sex differences in eating behaviour (e.g. women are more likely to be dieters or emotional eaters than men). The present study investigates this assumption in a large representative community sample while incorporating a comprehensive set of psychological eating-related variables. A community sample was employed to: (i) determine sex differences in (un)healthy snack consumption and psychological eating-related variables (e.g. emotional eating, intention to eat healthily); (ii) examine whether sex predicts energy intake from (un)healthy snacks over and above psychological variables; and (iii) investigate the relationship between psychological variables and snack intake for men and women separately. Snack consumption was assessed with a 7d snack diary; the psychological eating-related variables with questionnaires. Participants were members of an Internet survey panel that is based on a true probability sample of households in the Netherlands. Men and women (n 1292; 45 % male), with a mean age of 51·23 (sd 16·78) years and a mean BMI of 25·62 (sd 4·75) kg/m2. Results revealed that women consumed more healthy and less unhealthy snacks than men and they scored higher than men on emotional and restrained eating. Women also more often reported appearance and health-related concerns about their eating behaviour, but men and women did not differ with regard to external eating or their intentions to eat more healthily. The relationships between psychological eating-related variables and snack intake were similar for men and women, indicating that snack intake is predicted by the same variables for men and women. It is concluded that some small sex differences in psychological eating-related variables exist, but based on the present data there is no need for interventions aimed at promoting healthy eating to target different predictors according to sex.

Morphology of transverse aeolian ridges (TARs) on Mars from a large sample: Further evidence of a megaripple origin?

NASA Astrophysics Data System (ADS)

Hugenholtz, Chris H.; Barchyn, Thomas E.; Boulding, Adam

2017-04-01

Using HiRISE digital terrain models (DTMs), we developed a large morphological dataset to examine the three-dimensional shape, size, and scaling of Martian transverse aeolian ridges (TARs). Considerable debate exists on the characteristic morphology of TARs and the origins of these enigmatic bedforms. Some researchers suggest polygenesis or multiple classes of similar bedforms. Reliably characterizing the morphology of TARs is an essential prerequisite to developing and evaluating process-based models of TAR genesis and unraveling aeolian processes on the surface of Mars. We present measurements of TAR morphology from a large, DTM-derived dataset (n = 2295). We focused on TARs with 'simple' morphologies in order enable more defensible discretization. Histograms and cumulative log-frequency plots of morphometric parameters (length, width, height, elongation ratio, and wavelength) indicate the sample represents a continuum of bedforms from a single population. A typical TAR from our dataset is 88.5 m long (longest planview axis), 17.3 m wide (shortest planview axis), 1.3 m tall, and has a wavelength of 25.8 m. Combined with these data, the bulk of evidence presented to date suggests that interpreting TARs as megaripples is the most viable working hypothesis.

Evidence of niche partitioning among bacteria living on plastics, organic particles and surrounding seawaters.

PubMed

Dussud, C; Meistertzheim, A L; Conan, P; Pujo-Pay, M; George, M; Fabre, P; Coudane, J; Higgs, P; Elineau, A; Pedrotti, M L; Gorsky, G; Ghiglione, J F

2018-05-01

Plastic pollution is widespread in ocean ecosystems worldwide, but it is unknown if plastic offers a unique habitat for bacteria compared to communities in the water column and attached to naturally-occurring organic particles. The large set of samples taken during the Tara-Mediterranean expedition revealed for the first time a clear niche partitioning between free-living (FL), organic particle-attached (PA) and the recently introduced plastic marine debris (PMD). Bacterial counts in PMD presented higher cell enrichment factors than generally observed for PA fraction, when compared to FL bacteria in the surrounding waters. Taxonomic diversity was also higher in the PMD communities, where higher evenness indicated a favorable environment for a very large number of species. Cyanobacteria were particularly overrepresented in PMD, together with essential functions for biofilm formation and maturation. The community distinction between the three habitats was consistent across the large-scale sampling in the Western Mediterranean basin. 'Plastic specific bacteria' recovered only on the PMD represented half of the OTUs, thus forming a distinct habitat that should be further considered for understanding microbial biodiversity in changing marine ecosystems. Copyright © 2017. Published by Elsevier Ltd.

Evaluation of exposure to lead from drinking water in large buildings.

PubMed

Deshommes, Elise; Andrews, Robert C; Gagnon, Graham; McCluskey, Tim; McIlwain, Brad; Doré, Evelyne; Nour, Shokoufeh; Prévost, Michèle

2016-08-01

Lead results from 78,971 water samples collected in four Canadian provinces from elementary schools, daycares, and other large buildings using regulatory and investigative sampling protocols were analyzed to provide lead concentration distributions. Maximum concentrations reached 13,200 and 3890 μg/L following long and short stagnation periods respectively. High lead levels were persistent in some large buildings, reflected by high median values considering all taps, or specific to a few taps in the building. Simulations using the Integrated Uptake Biokinetic (IEUBK) model and lead concentrations after 30 min of stagnation in the dataset showed that, for most buildings, exposure to lead at the tap does not increase children's blood lead levels (BLLs). However, buildings or taps with extreme concentrations represent a significant health risk to young children attending school or daycare, as the estimated BLL far exceeded the 5 μg/dL threshold. Ingestion of water from specific taps could lead to acute exposure. Finally, for a few taps, the total daily lead intake reached the former World Health Organization (WHO) tolerable level for adults, suggesting potential health risks. Copyright © 2016 Elsevier Ltd. All rights reserved.

Possible observation of Griffith phase over large temperature range in plasma sintered La0.67Ca0.33MnO3

NASA Astrophysics Data System (ADS)

Mishra, D. K.; Roul, B. K.; Singh, S. K.; Srinivasu, V. V.

2018-02-01

We report on the possible observation of Griffith phase in a wide range of temperature (>272-378 K) in the 2.5 min plasma sintered La0.67Ca0.33MnO3 (LCMO) as deduced from careful electron spin resonance studies. This is 106 K higher than the paramagnetic to ferromagnetic transition (Curie transition ∼272 K) temperature. The indication of Griffith phase in such a wide range is not reported earlier by any group. We purposefully prepared LCMO samples by plasma sintering technique so as to create a disordered structure by rapid quenching which we believe, is the prime reason for the observation of Griffith Phase above the Curie transition temperature. The inverse susceptibility curve represents the existence of ferromagnetic cluster in paramagnetic region. The large resonance peak width (40-60 mT) within the temperature range 330-378 K confirms the sample magnetically inhomogeneity which is also established from our electron probe microstructure analysis (EPMA). EPMA establishes the presence of higher percentage of Mn3+ cluster in comparison to Mn4+. This is the reason for which Griffith state is enhanced largely to a higher range of temperature.

Mineral particles content in recent snow at Summit (Greenland)

NASA Astrophysics Data System (ADS)

Drab, E.; Gaudichet, A.; Jaffrezo, J. L.; Colin, J. L.

The mineral insoluble fraction of snowpit samples collected at Summit is investigated, representing deposition from summer 1987 to summer 1991. We attempt to describe the particles which are observed in the series, with very large seasonal variations. Elemental, mineralogical and size distribution studies are carried out on four samples selected according to the chemical profile of the snowpit (two samples from spring and two from winter) using X-ray fluorescence spectrometry and analytical transmission electron microscopy. Results indicate a large predominance of the soil-derived particles originating from arid or semi-arid regions of the Northern Hemisphere. The mineralogy clearly indicates a high contribution for the muscovite-illite associated with a low kaolinite/chlorite ratio, together with the rather lack of smectite. This supports the hypothesis of an Asian source. Several other factors are consistent with this Asian source, like the recent climatology and the good timing between the Asian dust storms period and the peak of dust concentration in the ice. The mineralogy of the insoluble particles in the snow is similar between winter and spring, suggesting that the change of concentration between the seasons is more strongly linked to changes of atmospheric parameters than changes of the source regions.

Topography of acute stroke in a sample of 439 right brain damaged patients.

PubMed

Sperber, Christoph; Karnath, Hans-Otto

2016-01-01

Knowledge of the typical lesion topography and volumetry is important for clinical stroke diagnosis as well as for anatomo-behavioral lesion mapping analyses. Here we used modern lesion analysis techniques to examine the naturally occurring lesion patterns caused by ischemic and by hemorrhagic infarcts in a large, representative acute stroke patient sample. Acute MR and CT imaging of 439 consecutively admitted right-hemispheric stroke patients from a well-defined catchment area suffering from ischemia (n = 367) or hemorrhage (n = 72) were normalized and mapped in reference to stereotaxic anatomical atlases. For ischemic infarcts, highest frequencies of stroke were observed in the insula, putamen, operculum and superior temporal cortex, as well as the inferior and superior occipito-frontal fascicles, superior longitudinal fascicle, uncinate fascicle, and the acoustic radiation. The maximum overlay of hemorrhages was located more posteriorly and more medially, involving posterior areas of the insula, Heschl's gyrus, and putamen. Lesion size was largest in frontal and anterior areas and lowest in subcortical and posterior areas. The large and unbiased sample of stroke patients used in the present study accumulated the different sub-patterns to identify the global topographic and volumetric pattern of right hemisphere stroke in humans.

Cancerous epithelial cell lines shed extracellular vesicles with a bimodal size distribution that is sensitive to glutamine inhibition

NASA Astrophysics Data System (ADS)

Santana, Steven Michael; Antonyak, Marc A.; Cerione, Richard A.; Kirby, Brian J.

2014-12-01

Extracellular shed vesicles (ESVs) facilitate a unique mode of cell-cell communication wherein vesicle uptake can induce a change in the recipient cell's state. Despite the intensity of ESV research, currently reported data represent the bulk characterization of concentrated vesicle samples with little attention paid to heterogeneity. ESV populations likely represent diversity in mechanisms of formation, cargo and size. To better understand ESV subpopulations and the signaling cascades implicated in their formation, we characterize ESV size distributions to identify subpopulations in normal and cancerous epithelial cells. We have discovered that cancer cells exhibit bimodal ESV distributions, one small-diameter and another large-diameter population, suggesting that two mechanisms may govern ESV formation, an exosome population and a cancer-specific microvesicle population. Altered glutamine metabolism in cancer is thought to fuel cancer growth but may also support metastatic niche formation through microvesicle production. We describe the role of a glutaminase inhibitor, compound 968, in ESV production. We have discovered that inhibiting glutamine metabolism significantly impairs large-diameter microvesicle production in cancer cells.

MicroRNAs are suitable for assessment as biomarkers from formalin-fixed paraffin-embedded tissue, and miR-24 represents an appropriate reference microRNA for diffuse large B-cell lymphoma studies.

PubMed

Culpin, Rachel Emily; Sieniawski, Michal; Proctor, Stephen John; Menon, Geetha; Mainou-Fowler, Tryfonia

2013-03-01

Tissue biopsy specimens in the form of formalin-fixed paraffin-embedded tissue (FFPET) represent a valuable resource for biomarker identification and validation. However, to date, they remain an underused asset due to uncertainty regarding RNA extraction and the reliability of downstream techniques, including quantitative RT-PCR. Recently, much interest has emerged in the study of microRNAs; small single-stranded RNAs with a role in transcriptional regulation, that are thought to be well preserved in FFPET. In this study, we show that microRNA expression is comparable between FFPET and matched fresh-frozen samples (miR-17-5p: p=0.01, miR-92: p=0.003), and demonstrate that no significant deterioration in expression occurs over prolonged FFPET storage (p=0.06). Furthermore, microRNA expression is equivalent dependant on RNA extraction method (p<0.001) or DNAse treatment of total RNA (p<0.001). Finally, we validate miR-24 as a suitable reference microRNA for diffuse large B-cell lymphoma (DLBCL) FFPET studies.

Secure base representations in middle childhood across two Western cultures: Associations with parental attachment representations and maternal reports of behavior problems.

PubMed

Waters, Theodore E A; Bosmans, Guy; Vandevivere, Eva; Dujardin, Adinda; Waters, Harriet S

2015-08-01

Recent work examining the content and organization of attachment representations suggests that 1 way in which we represent the attachment relationship is in the form of a cognitive script. This work has largely focused on early childhood or adolescence/adulthood, leaving a large gap in our understanding of script-like attachment representations in the middle childhood period. We present 2 studies and provide 3 critical pieces of evidence regarding the presence of a script-like representation of the attachment relationship in middle childhood. We present evidence that a middle childhood attachment script assessment tapped a stable underlying script using samples drawn from 2 western cultures, the United States (Study 1) and Belgium (Study 2). We also found evidence suggestive of the intergenerational transmission of secure base script knowledge (Study 1) and relations between secure base script knowledge and symptoms of psychopathology in middle childhood (Study 2). The results from this investigation represent an important downward extension of the secure base script construct. (c) 2015 APA, all rights reserved).

Secure Base Representations in Middle Childhood Across Two Western Cultures: Associations with Parental Attachment Representations and Maternal Reports of Behavior Problems

PubMed Central

Waters, Theodore E. A.; Bosmans, Guy; Vandevivere, Eva; Dujardin, Adinda; Waters, Harriet S.

2015-01-01

Recent work examining the content and organization of attachment representations suggests that one way in which we represent the attachment relationship is in the form of a cognitive script. That said, this work has largely focused on early childhood or adolescence/adulthood, leaving a large gap in our understanding of script-like attachment representations in the middle childhood period. We present two studies and provide three critical pieces of evidence regarding the presence of a script-like representation of the attachment relationship in middle childhood. We present evidence that a middle childhood attachment script assessment tapped a stable underlying script using samples drawn from two western cultures, the United States (Study 1) and Belgium (Study 2). We also found evidence suggestive of the intergenerational transmission of secure base script knowledge (Study 1) and relations between secure base script knowledge and symptoms of psychopathology in middle childhood (Study 2). The results from this investigation represent an important downward extension of the secure base script construct. PMID:26147774

Volatile and semivolatile organic compounds in laboratory ...

EPA Pesticide Factsheets

Speciated volatile organic compounds (VOCs) and organic fine particulate matter (PM2.5) mass emission factors were determined from laboratory peat fire experiments. Peat samples originated from two wildlife reserves located near the coast of North Carolina, U.S. Gas and particulate organics were quantified by gas chromatography/mass spectrometry and by high pressure liquid chromatography. Hazardous air pollutants (HAPs) accounted for a large fraction (~60 %) of the speciated VOC emissions from peat burning, including large contributions of acetaldehyde, formaldehyde, benzene, toluene, and chloromethane. Speciated organic PM2.5 mass was dominated by the following compound classes: organic acids, levoglucosan, n-alkanes, and n-alkenes. Emission factors for PM2.5 organic acids including n-alkanoic acids, n-alkenoic acids, n-alkanedioic acids, and aromatic acids were reported for the first time for peat burning, representing the largest fraction of organic carbon (OC) mass (11-12 %) of all speciated compound classes measured in this work. Levoglucosan contributed 2-3 % of the OC mass, while methoxyphenols represented 0.2-0.3 % of the OC mass on a carbon mass basis. Retene was the most abundant particulate phase polycyclic aromatic hydrocarbon. Total HAP VOC and particulate polycyclic aromatic hydrocarbon emissions from a 2008 peat wildfire in North Carolina were estimated, suggesting that peat fires can contribute a large fraction of state-wide HAP emissions. This p

Design and analysis of large-scale biological rhythm studies: a comparison of algorithms for detecting periodic signals in biological data

PubMed Central

Deckard, Anastasia; Anafi, Ron C.; Hogenesch, John B.; Haase, Steven B.; Harer, John

2013-01-01

Motivation: To discover and study periodic processes in biological systems, we sought to identify periodic patterns in their gene expression data. We surveyed a large number of available methods for identifying periodicity in time series data and chose representatives of different mathematical perspectives that performed well on both synthetic data and biological data. Synthetic data were used to evaluate how each algorithm responds to different curve shapes, periods, phase shifts, noise levels and sampling rates. The biological datasets we tested represent a variety of periodic processes from different organisms, including the cell cycle and metabolic cycle in Saccharomyces cerevisiae, circadian rhythms in Mus musculus and the root clock in Arabidopsis thaliana. Results: From these results, we discovered that each algorithm had different strengths. Based on our findings, we make recommendations for selecting and applying these methods depending on the nature of the data and the periodic patterns of interest. Additionally, these results can also be used to inform the design of large-scale biological rhythm experiments so that the resulting data can be used with these algorithms to detect periodic signals more effectively. Contact: anastasia.deckard@duke.edu Supplementary information: Supplementary data are available at Bioinformatics online. PMID:24058056

After site selection and before data analysis: sampling, sorting, and laboratory procedures used in stream benthic macroinvertebrate monitoring programs by USA state agencies

USGS Publications Warehouse

Carter, James L.; Resh, Vincent H.

2001-01-01

A survey of methods used by US state agencies for collecting and processing benthic macroinvertebrate samples from streams was conducted by questionnaire; 90 responses were received and used to describe trends in methods. The responses represented an estimated 13,000-15,000 samples collected and processed per year. Kicknet devices were used in 64.5% of the methods; other sampling devices included fixed-area samplers (Surber and Hess), artificial substrates (Hester-Dendy and rock baskets), grabs, and dipnets. Regional differences existed, e.g., the 1-m kicknet was used more often in the eastern US than in the western US. Mesh sizes varied among programs but 80.2% of the methods used a mesh size between 500 and 600 (mu or u)m. Mesh size variations within US Environmental Protection Agency regions were large, with size differences ranging from 100 to 700 (mu or u)m. Most samples collected were composites; the mean area sampled was 1.7 m2. Samples rarely were collected using a random method (4.7%); most samples (70.6%) were collected using "expert opinion", which may make data obtained operator-specific. Only 26.3% of the methods sorted all the organisms from a sample; the remainder subsampled in the laboratory. The most common method of subsampling was to remove 100 organisms (range = 100-550). The magnification used for sorting ranged from 1 (sorting by eye) to 30x, which results in inconsistent separation of macroinvertebrates from detritus. In addition to subsampling, 53% of the methods sorted large/rare organisms from a sample. The taxonomic level used for identifying organisms varied among taxa; Ephemeroptera, Plecoptera, and Trichoptera were generally identified to a finer taxonomic resolution (genus and species) than other taxa. Because there currently exists a large range of field and laboratory methods used by state programs, calibration among all programs to increase data comparability would be exceptionally challenging. However, because many techniques are shared among methods, limited testing could be designed to evaluate whether procedural differences affect the ability to determine levels of environmental impairment using benthic macroinvertebrate communities.

Australian Schizophrenia Research Bank: a database of comprehensive clinical, endophenotypic and genetic data for aetiological studies of schizophrenia.

PubMed

Loughland, Carmel; Draganic, Daren; McCabe, Kathryn; Richards, Jacqueline; Nasir, Aslam; Allen, Joanne; Catts, Stanley; Jablensky, Assen; Henskens, Frans; Michie, Patricia; Mowry, Bryan; Pantelis, Christos; Schall, Ulrich; Scott, Rodney; Tooney, Paul; Carr, Vaughan

2010-11-01

This article describes the establishment of the Australian Schizophrenia Research Bank (ASRB), which operates to collect, store and distribute linked clinical, cognitive, neuroimaging and genetic data from a large sample of people with schizophrenia and healthy controls. Recruitment sources for the schizophrenia sample include a multi-media national advertising campaign, inpatient and community treatment services and non-government support agencies. Healthy controls have been recruited primarily through multi-media advertisements. All participants undergo an extensive diagnostic and family history assessment, neuropsychological evaluation, and blood sample donation for genetic studies. Selected individuals also complete structural MRI scans. Preliminary analyses of 493 schizophrenia cases and 293 healthy controls are reported. Mean age was 39.54 years (SD = 11.1) for the schizophrenia participants and 37.38 years (SD = 13.12) for healthy controls. Compared to the controls, features of the schizophrenia sample included a higher proportion of males (cases 65.9%; controls 46.8%), fewer living in married or de facto relationships (cases 16.1%; controls 53.6%) and fewer years of education (cases 13.05, SD = 2.84; controls 15.14, SD = 3.13), as well as lower current IQ (cases 102.68, SD = 15.51; controls 118.28, SD = 10.18). These and other sample characteristics are compared to those reported in another large Australian sample (i.e. the Low Prevalence Disorders Study), revealing some differences that reflect the different sampling methods of these two studies. The ASRB is a valuable and accessible schizophrenia research facility for use by approved scientific investigators. As recruitment continues, the approach to sampling for both cases and controls will need to be modified to ensure that the ASRB samples are as broadly representative as possible of all cases of schizophrenia and healthy controls.

Middle atmosphere project. A semi-spectral numerical model for the large-scale stratospheric circulation

NASA Technical Reports Server (NTRS)

Holton, J. R.; Wehrbein, W.

1979-01-01

The complete model is a semispectral model in which the longitudinal dependence is represented by expansion in zonal harmonics while the latitude and height dependencies are represented by a finite difference grid. The model is based on the primitive equations in the log pressure coordinate system. The lower boundary of the model domain is set at the 100 mb level (i.e., near the tropopause) and the effects of tropospheric forcing are included in the lower boundary condition. The upper boundary is at approximately 96 km, and the latitudinal extent is either global or hemispheric. The basic differential equations and boundary conditions are outlined. The finite difference equations are described. The initial conditions are discussed and a sample calculation is presented. The FORTRAN code is given in the appendix.

Multiple Reaction Monitoring Enables Precise Quantification of 97 Proteins in Dried Blood Spots*

PubMed Central

Chambers, Andrew G.; Percy, Andrew J.; Yang, Juncong; Borchers, Christoph H.

2015-01-01

The dried blood spot (DBS) methodology provides a minimally invasive approach to sample collection and enables room-temperature storage for most analytes. DBS samples have successfully been analyzed by liquid chromatography multiple reaction monitoring mass spectrometry (LC/MRM-MS) to quantify a large range of small molecule biomarkers and drugs; however, this strategy has only recently been explored for MS-based proteomics applications. Here we report the development of a highly multiplexed MRM assay to quantify endogenous proteins in human DBS samples. This assay uses matching stable isotope-labeled standard peptides for precise, relative quantification, and standard curves to characterize the analytical performance. A total of 169 peptides, corresponding to 97 proteins, were quantified in the final assay with an average linear dynamic range of 207-fold and an average R2 value of 0.987. The total range of this assay spanned almost 5 orders of magnitude from serum albumin (P02768) at 18.0 mg/ml down to cholinesterase (P06276) at 190 ng/ml. The average intra-assay and inter-assay precision for 6 biological samples ranged from 6.1–7.5% CV and 9.5–11.0% CV, respectively. The majority of peptide targets were stable after 154 days at storage temperatures from −20 °C to 37 °C. Furthermore, protein concentration ratios between matching DBS and whole blood samples were largely constant (<20% CV) across six biological samples. This assay represents the highest multiplexing yet achieved for targeted protein quantification in DBS samples and is suitable for biomedical research applications. PMID:26342038

Sensitive and Rapid Detection of Viable Giardia Cysts and Cryptosporidium parvum Oocysts in Large-Volume Water Samples with Wound Fiberglass Cartridge Filters and Reverse Transcription-PCR

PubMed Central

Kaucner, Christine; Stinear, Timothy

1998-01-01

We recently described a reverse transcription-PCR (RT-PCR) for detecting low numbers of viable Cryptosporidium parvum oocysts spiked into clarified environmental water concentrates. We have now modified the assay for direct analysis of primary sample concentrates with simultaneous detection of viable C. parvum oocysts, Giardia cysts, and a novel type of internal positive control (IPC). The IPC was designed to assess both efficiency of mRNA isolation and potential RT-PCR inhibition. Sensitivity testing showed that low numbers of organisms, in the range of a single viable cyst and oocyst, could be detected when spiked into 100-μl packed pellet volumes of concentrates from creek and river water samples. The RT-PCR was compared with an immunofluorescence (IF) assay by analyzing 29 nonspiked environmental water samples. Sample volumes of 20 to 1,500 liters were concentrated with a wound fiberglass cartridge filter. Frequency of detection for viable Giardia cysts increased from 24% by IF microscopy to 69% by RT-PCR. Viable C. parvum oocysts were detected only once by RT-PCR (3%) in contrast to detection of viable Cryptosporidium spp. in four samples by IF microscopy (14%), suggesting that Cryptosporidium species other than C. parvum were present in the water. This combination of the large-volume sampling method with RT-PCR represents a significant advance in terms of protozoan pathogen monitoring and in the wider application of PCR technology to this field of microbiology. PMID:9572946

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

PubMed Central

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

2016-01-01

Here, we report the results of a large-scale PCR survey on the prevalence and diversity of adenoviruses (AdVs) in samples collected randomly from free-living reptiles. On the territories of the Guadarrama Mountains National Park in Central Spain and of the Chafarinas Islands in North Africa, cloacal swabs were taken from 318 specimens of eight native species representing five squamate reptilian families. The healthy-looking animals had been captured temporarily for physiological and ethological examinations, after which they were released. We found 22 AdV-positive samples in representatives of three species, all from Central Spain. Sequence analysis of the PCR products revealed the existence of three hitherto unknown AdVs in 11 Carpetane rock lizards (Iberolacerta cyreni), nine Iberian worm lizards (Blanus cinereus), and two Iberian green lizards (Lacerta schreiberi), respectively. Phylogeny inference showed every novel putative virus to be a member of the genus Atadenovirus. This is the very first description of the occurrence of AdVs in amphisbaenian and lacertid hosts. Unlike all squamate atadenoviruses examined previously, two of the novel putative AdVs had A+T rich DNA, a feature generally deemed to mirror previous host switch events. Our results shed new light on the diversity and evolution of atadenoviruses. PMID:27399970

Historical mitochondrial diversity in African leopards (Panthera pardus) revealed by archival museum specimens.

PubMed

Anco, Corey; Kolokotronis, Sergios-Orestis; Henschel, Philipp; Cunningham, Seth W; Amato, George; Hekkala, Evon

2018-04-01

Once found throughout Africa and Eurasia, the leopard (Panthera pardus) was recently uplisted from Near Threatened to Vulnerable by the International Union for the Conservation of Nature (IUCN). Historically, more than 50% of the leopard's global range occurred in continental Africa, yet sampling from this part of the species' distribution is only sparsely represented in prior studies examining patterns of genetic variation at the continental or global level. Broad sampling to determine baseline patterns of genetic variation throughout the leopard's historical distribution is important, as these measures are currently used by the IUCN to direct conservation priorities and management plans. By including data from 182 historical museum specimens, faecal samples from ongoing field surveys, and published sequences representing sub-Saharan Africa, we identify previously unrecognized genetic diversity in African leopards. Our mtDNA data indicates high levels of divergence among regional populations and strongly differentiated lineages in West Africa on par with recent studies of other large vertebrates. We provide a reference benchmark of genetic diversity in African leopards against which future monitoring can be compared. These findings emphasize the utility of historical museum collections in understanding the processes that shape present biodiversity. Additionally, we suggest future research to clarify African leopard taxonomy and to differentiate between delineated units requiring monitoring or conservation action.

Physical fitness reference standards in fibromyalgia: The al-Ándalus project.

PubMed

Álvarez-Gallardo, I C; Carbonell-Baeza, A; Segura-Jiménez, V; Soriano-Maldonado, A; Intemann, T; Aparicio, V A; Estévez-López, F; Camiletti-Moirón, D; Herrador-Colmenero, M; Ruiz, J R; Delgado-Fernández, M; Ortega, F B

2017-11-01

We aimed (1) to report age-specific physical fitness levels in people with fibromyalgia of a representative sample from Andalusia; and (2) to compare the fitness levels of people with fibromyalgia with non-fibromyalgia controls. This cross-sectional study included 468 (21 men) patients with fibromyalgia and 360 (55 men) controls. The fibromyalgia sample was geographically representative from southern Spain. Physical fitness was assessed with the Senior Fitness Test battery plus the handgrip test. We applied the Generalized Additive Model for Location, Scale and Shape to calculate percentile curves for women and fitted mean curves using a linear regression for men. Our results show that people with fibromyalgia reached worse performance in all fitness tests than controls (P < 0.001) in all age ranges (P < 0.001). This study provides a comprehensive description of age-specific physical fitness levels among patients with fibromyalgia and controls in a large sample of patients with fibromyalgia from southern of Spain. Physical fitness levels of people with fibromyalgia from Andalusia are very low in comparison with age-matched healthy controls. This information could be useful to correctly interpret physical fitness assessments and helping health care providers to identify individuals at risk for losing physical independence. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

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

PubMed

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

2016-01-01

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

Diverse Geno- and Phenotypes of Persistent Listeria monocytogenes Isolates from Fermented Meat Sausage Production Facilities in Portugal ▿

PubMed Central

Ferreira, V.; Barbosa, J.; Stasiewicz, M.; Vongkamjan, K.; Moreno Switt, A.; Hogg, T.; Gibbs, P.; Teixeira, P.; Wiedmann, M.

2011-01-01

The persistence of Listeria monocytogenes in food-associated environments represents a key factor in transmission of this pathogen. To identify persistent and transient strains associated with production of fermented meat sausages in northern Portugal, 1,723 L. monocytogenes isolates from raw material and finished products from 11 processors were initially characterized by random amplification of polymorphic DNA (RAPD), PCR-based molecular serotyping, and epidemic clone characterization, as well as cadmium, arsenic, and tetracycline resistance typing. Pulsed-field gel electrophoresis (PFGE) typing of 240 representative isolates provided evidence for persistence of L. monocytogenes for periods of time ranging from 10 to 32 months for all seven processors for which isolates from different production dates were available. Among 50 L. monocytogenes isolates that included one representative for each PFGE pattern obtained from a given sample, 12 isolates showed reduced invasion efficiency in Caco-2 cells, including 8 isolates with premature stop codons in inlA. Among 41 isolates representing sporadic and persistent PFGE types, 22 isolates represented lysogens. Neither strains with reduced invasion nor lysogens were overrepresented among persistent isolates. While the susceptibility of isolates to lysogenic phages also did not correlate with persistence, it appeared to be associated with molecular serotype. Our data show the following. (i) RAPD may not be suitable for analysis of large sets of L. monocytogenes isolates. (ii) While a large diversity of L. monocytogenes subtypes is found in Portuguese fermented meat sausages, persistence of L. monocytogenes in this food chain is common. (iii) Persistent L. monocytogenes strains are diverse and do not appear to be characterized by unique genetic or phenotypic characteristics. PMID:21378045

Evaluation of a New Technique for iFOBT Utilising a New Sample Collection Device with Increased Buffer Stability.

PubMed

Bruns-Toepler, Markus; Hardt, Philip

2017-07-01

The aims of the present study were: (i) Evaluate specificity and sensitivity of Hb Smart enzyme-linked immunosorbent assay (ELISA) (ScheBo Biotech) compared to colonoscopy results and (ii) assess stability of a new sample collection device containing a newly formulated buffer to extract haemoglobin using buffer and stool samples spiked with defined concentrations of haemoglobin. Stool samples were quantified with the ELISA method. The stability of haemoglobin in the extraction buffer and in native stool samples, respectively, was determined daily by ELISA during storage for 5 days at 4°C and at room temperature after addition of haemoglobin. Haemoglobin ELISA had a sensitivity of 78.4% for detection of CRC with a specificity of 98%. Haemoglobin extracted in corresponding extraction buffer demonstrated stability throughout storage for 5 days at 4°C and at room temperature. Hb Smart represents a very promising tool for large-scale screening of CRC with regard to sample handling, stability and analysis of haemoglobin in faeces. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Some physical properties of naturally irradiated fluorite

USGS Publications Warehouse

Berman, Robert

1955-01-01

Five samples of purple fluorite found in association with radioactive, materials, and a synthetic colorless control sample were studied and compared.  Before and after heating, observations were made on specific gravity, index of refraction, unit-cell size, breadth of X-ray diffraction lines, and fluorescence.  The purple samples became colorless on heating above 175° C.  During the process, observations were made on color, thermoluminescence, and differential thermal analysis curves.  There were strong correlations between the various physical properties, and it was found possible to arrange the samples in order of increasing difference in their physical properties from the control sample. This order apparently represents increasing structural damage by radiation; if so, it correlates with decreasing specific gravity, increasing index of refraction, broadening of X-ray lines, and increasingly strong exothermic reactions on annealing. The differences between the samples in index of refraction and X-ray pattern are largely eliminated on annealing.  Annealing begins at 1750 C; thermoluminescence at lower temperatures is due to electrons escaping from the metastable potential traps, not the destruction of those traps which takes place on annealing.

Sample Preparation for Electron Probe Microanalysis—Pushing the Limits

PubMed Central

Geller, Joseph D.; Engle, Paul D.

2002-01-01

There are two fundamental considerations in preparing samples for electron probe microanalysis (EPMA). The first one may seem obvious, but we often find it is overlooked. That is, the sample analyzed should be representative of the population from which it comes. The second is a direct result of the assumptions in the calculations used to convert x-ray intensity ratios, between the sample and standard, to concentrations. Samples originate from a wide range of sources. During their journey to being excited under the electron beam for the production of x rays there are many possibilities for sample alteration. Handling can contaminate samples by adding extraneous matter. In preparation, the various abrasives used in sizing the sample by sawing, grinding and polishing can embed themselves. The most accurate composition of a contaminated sample is, at best, not representative of the original sample; it is misleading. Our laboratory performs EPMA analysis on customer submitted samples and prepares over 250 different calibration standards including pure elements, compounds, alloys, glasses and minerals. This large variety of samples does not lend itself to mass production techniques, including automatic polishing. Our manual preparation techniques are designed individually for each sample. The use of automated preparation equipment does not lend itself to this environment, and is not included in this manuscript. The final step in quantitative electron probe microanalysis is the conversion of x-ray intensities ratios, known as the “k-ratios,” to composition (in mass fraction or atomic percent) and/or film thickness. Of the many assumptions made in the ZAF (where these letters stand for atomic number, absorption and fluorescence) corrections the localized geometry between the sample and electron beam, or takeoff angle, must be accurately known. Small angular errors can lead to significant errors in the final results. The sample preparation technique then becomes very important, and, under certain conditions, may even be the limiting factor in the analytical uncertainty budget. This paper considers preparing samples to get known geometries. It will not address the analysis of samples with irregular, unprepared surfaces or unknown geometries. PMID:27446757

Lessons from the Canadian national health information technology plan for the United States: opinions of key Canadian experts.

PubMed

Zimlichman, Eyal; Rozenblum, Ronen; Salzberg, Claudia A; Jang, Yeona; Tamblyn, Melissa; Tamblyn, Robyn; Bates, David W

2012-01-01

To summarize the Canadian health information technology (HIT) policy experience and impart lessons learned to the US as it determines its policy in this area. Qualitative analysis of interviews with identified key stakeholders followed by an electronic survey. We conducted semi-structured interviews with 29 key Canadian HIT policy and opinion leaders and used a grounded theory approach to analyze the results. The informant sample was chosen to provide views from different stakeholder groups including national representatives and regional representatives from three Canadian provinces. Canadian informants believed that much of the current US direction is positive, especially regarding incentives and meaningful use, but that there are key opportunities for the US to emphasize direct engagement with providers, define a clear business case for them, sponsor large scale evaluations to assess HIT impact in a broad array of settings, determine standards but also enable access to resources needed for mid-course corrections of standards when issues are identified, and, finally, leverage implementation of digital imaging systems. Not all stakeholder groups were included, such as providers or patients. In addition, as in all qualitative research, a selection bias could be present due to the relatively small sample size. Based on Canadian experience with HIT policy, stakeholders identified as lessons for the US the need to increase direct engagement with providers and the importance of defining the business case for HIT, which can be achieved through large scale evaluations, and of recognizing and leveraging successes as they emerge.

Desiderata for Healthcare Integrated Data Repositories Based on Architectural Comparison of Three Public Repositories

PubMed Central

Huser, Vojtech; Cimino, James J.

2013-01-01

Integrated data repositories (IDRs) are indispensable tools for numerous biomedical research studies. We compare three large IDRs (Informatics for Integrating Biology and the Bedside (i2b2), HMO Research Network’s Virtual Data Warehouse (VDW) and Observational Medical Outcomes Partnership (OMOP) repository) in order to identify common architectural features that enable efficient storage and organization of large amounts of clinical data. We define three high-level classes of underlying data storage models and we analyze each repository using this classification. We look at how a set of sample facts is represented in each repository and conclude with a list of desiderata for IDRs that deal with the information storage model, terminology model, data integration and value-sets management. PMID:24551366

Desiderata for healthcare integrated data repositories based on architectural comparison of three public repositories.

PubMed

Huser, Vojtech; Cimino, James J

2013-01-01

Integrated data repositories (IDRs) are indispensable tools for numerous biomedical research studies. We compare three large IDRs (Informatics for Integrating Biology and the Bedside (i2b2), HMO Research Network's Virtual Data Warehouse (VDW) and Observational Medical Outcomes Partnership (OMOP) repository) in order to identify common architectural features that enable efficient storage and organization of large amounts of clinical data. We define three high-level classes of underlying data storage models and we analyze each repository using this classification. We look at how a set of sample facts is represented in each repository and conclude with a list of desiderata for IDRs that deal with the information storage model, terminology model, data integration and value-sets management.

Heat exchanger-ingot casting/slicing process, phase 1: Silicon sheet growth development for the large area silicon sheet task of the low cost silicon solar array project

NASA Technical Reports Server (NTRS)

Schmid, F.; Khattak, C. P.

1977-01-01

A controlled growth, heat-flow and cool-down process is described that yielded silicon with a high degree of single crystallinity. Even when the seed melted out, very large grains formed. Solar cell samples made from cast material yielded conversion efficiency of over 9%. Representative characterizations of grown silicon demonstrated a dislocation density of less than 100/sq cm and a minority carrier diffusion length of 31 micron. The source of silicon carbide in silicon ingots was identified to be from graphite retainers in contact with silica crucibles. Higher growth rates were achieved with the use of a graphite plug at the bottom of the silica crucible.

The MiMeS Survey of Magnetism in Massive Stars

NASA Astrophysics Data System (ADS)

Wade, G. A.; Grunhut, J. H.; MiMeS Collaboration

2012-12-01

The Magnetism in Massive Stars (MiMeS) survey represents a high-precision systematic search for magnetic fields in hot, massive OB stars. To date, MiMeS Large Programs (ESPaDOnS@CFHT, Narval@TBL, HARPSpol@ESO3.6 m) and associated PI programs (FORS@VLT) have yielded nearly 1200 circular spectropolarimetric observations of over 350 OB stars. Within this sample, 20 stars are detected as magnetic. Follow-up observations of new detections reveals (i) a large diversity of magnetic properties, (ii) ubiquitous evidence for magnetic wind confinement in optical spectra of all magnetic O stars, and (iii) the presence of strong, organized magnetic fields in all known Galactic Of?p stars, and iv) a complete absence of magnetic fields in classical Be stars.

Scaling ice microstructures from the laboratory to nature: cryo-EBSD on large samples.

NASA Astrophysics Data System (ADS)

Prior, David; Craw, Lisa; Kim, Daeyeong; Peyroux, Damian; Qi, Chao; Seidemann, Meike; Tooley, Lauren; Vaughan, Matthew; Wongpan, Pat

2017-04-01

Electron backscatter diffraction (EBSD) has extended significantly our ability to conduct detailed quantitative microstructural investigations of rocks, metals and ceramics. EBSD on ice was first developed in 2004. Techniques have improved significantly in the last decade and EBSD is now becoming more common in the microstructural analysis of ice. This is particularly true for laboratory-deformed ice where, in some cases, the fine grain sizes exclude the possibility of using a thin section of the ice. Having the orientations of all axes (rather than just the c-axis as in an optical method) yields important new information about ice microstructure. It is important to examine natural ice samples in the same way so that we can scale laboratory observations to nature. In the case of ice deformation, higher strain rates are used in the laboratory than those seen in nature. These are achieved by increasing stress and/or temperature and it is important to assess that the microstructures produced in the laboratory are comparable with those observed in nature. Natural ice samples are coarse grained. Glacier and ice sheet ice has a grain size from a few mm up to several cm. Sea and lake ice has grain sizes of a few cm to many metres. Thus extending EBSD analysis to larger sample sizes to include representative microstructures is needed. The chief impediments to working on large ice samples are sample exchange, limitations on stage motion and temperature control. Large ice samples cannot be transferred through a typical commercial cryo-transfer system that limits sample sizes. We transfer through a nitrogen glove box that encloses the main scanning electron microscope (SEM) door. The nitrogen atmosphere prevents the cold stage and the sample from becoming covered in frost. Having a long optimal working distance for EBSD (around 30mm for the Otago cryo-EBSD facility) , by moving the camera away from the pole piece, enables the stage to move without crashing into either the EBSD camera or the SEM pole piece (final lens). In theory a sample up to 100mm perpendicular to the tilt axis by 150mm parallel to the tilt axis can be analysed. In practice, the motion of our stage is restricted to maximum dimensions of 100 by 50mm by a conductive copper braid on our cold stage. Temperature control becomes harder as the samples become larger. If the samples become too warm then they will start to sublime and the quality of EBSD data will reduce. Large samples need to be relatively thin ( 5mm or less) so that conduction of heat to the cold stage is more effective at keeping the surface temperature low. In the Otago facility samples of up to 40mm by 40mm present little problem and can be analysed for several hours without significant sublimation. Larger samples need more care, e.g. fast sample transfer to keep the sample very cold. The largest samples we work on routinely are 40 by 60mm in size. We will show examples of EBSD data from glacial ice and sea ice from Antarctica and from large laboratory ice samples.

Multiscale pore structure and constitutive models of fine-grained rocks

NASA Astrophysics Data System (ADS)

Heath, J. E.; Dewers, T. A.; Shields, E. A.; Yoon, H.; Milliken, K. L.

2017-12-01

A foundational concept of continuum poromechanics is the representative elementary volume or REV: an amount of material large enough that pore- or grain-scale fluctuations in relevant properties are dissipated to a definable mean, but smaller than length scales of heterogeneity. We determine 2D-equivalent representative elementary areas (REAs) of pore areal fraction of three major types of mudrocks by applying multi-beam scanning electron microscopy (mSEM) to obtain terapixel image mosaics. Image analysis obtains pore areal fraction and pore size and shape as a function of progressively larger measurement areas. Using backscattering imaging and mSEM data, pores are identified by the components within which they occur, such as in organics or the clastic matrix. We correlate pore areal fraction with nano-indentation, micropillar compression, and axysimmetic testing at multiple length scales on a terrigenous-argillaceous mudrock sample. The combined data set is used to: investigate representative elementary volumes (and areas for the 2D images); determine if scale separation occurs; and determine if transport and mechanical properties at a given length scale can be statistically defined. Clear scale separation occurs between REAs and observable heterogeneity in two of the samples. A highly-laminated sample exhibits fine-scale heterogeneity and an overlapping in scales, in which case typical continuum assumptions on statistical variability may break down. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia LLC, a wholly owned subsidiary of Honeywell International Inc. for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA0003525.

Moving on From Representativeness: Testing the Utility of the Global Drug Survey.

PubMed

Barratt, Monica J; Ferris, Jason A; Zahnow, Renee; Palamar, Joseph J; Maier, Larissa J; Winstock, Adam R

2017-01-01

A decline in response rates in traditional household surveys, combined with increased internet coverage and decreased research budgets, has resulted in increased attractiveness of web survey research designs based on purposive and voluntary opt-in sampling strategies. In the study of hidden or stigmatised behaviours, such as cannabis use, web survey methods are increasingly common. However, opt-in web surveys are often heavily criticised due to their lack of sampling frame and unknown representativeness. In this article, we outline the current state of the debate about the relevance of pursuing representativeness, the state of probability sampling methods, and the utility of non-probability, web survey methods especially for accessing hidden or minority populations. Our article has two aims: (1) to present a comprehensive description of the methodology we use at Global Drug Survey (GDS), an annual cross-sectional web survey and (2) to compare the age and sex distributions of cannabis users who voluntarily completed (a) a household survey or (b) a large web-based purposive survey (GDS), across three countries: Australia, the United States, and Switzerland. We find that within each set of country comparisons, the demographic distributions among recent cannabis users are broadly similar, demonstrating that the age and sex distributions of those who volunteer to be surveyed are not vastly different between these non-probability and probability methods. We conclude that opt-in web surveys of hard-to-reach populations are an efficient way of gaining in-depth understanding of stigmatised behaviours and are appropriate, as long as they are not used to estimate drug use prevalence of the general population.

Childhood adversity and personality disorders: results from a nationally representative population-based study.

PubMed

Afifi, Tracie O; Mather, Amber; Boman, Jonathon; Fleisher, William; Enns, Murray W; Macmillan, Harriet; Sareen, Jitender

2011-06-01

Although, a large population-based literature exists on the relationship between childhood adversity and Axis I mental disorders, research on the link between childhood adversity and Axis II personality disorders (PDs) relies mainly on clinical samples. The purpose of the current study was to examine the relationship between a range of childhood adversities and PDs in a nationally representative sample while adjusting for Axis I mental disorders. Data were from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC; n=34,653; data collection 2004-2005); a nationally representative sample of the United States population aged 20 years and older. The results indicated that many types of childhood adversity were highly prevalent among individuals with PDs in the general population and childhood adversity was most consistently associated with schizotypal, antisocial, borderline, and narcissistic PDs. The most robust childhood adversity findings were for child abuse and neglect with cluster A and cluster B PDs after adjusting for all other types of childhood adversity, mood disorders, anxiety disorders, substance use disorders, other PD clusters, and sociodemographic variables (Odd Ratios ranging from 1.22 to 1.63). In these models, mood disorders, anxiety disorders, and substance use disorders also remained significantly associated with PD clusters (Odds Ratios ranging from 1.26 to 2.38). Further research is necessary to understand whether such exposure has a causal role in the association with PDs. In addition to preventing child maltreatment, it is important to determine ways to prevent impairment among those exposed to adversity, as this may reduce the development of PDs. Copyright © 2010 Elsevier Ltd. All rights reserved.

Moving on From Representativeness: Testing the Utility of the Global Drug Survey

PubMed Central

Barratt, Monica J; Ferris, Jason A; Zahnow, Renee; Palamar, Joseph J; Maier, Larissa J; Winstock, Adam R

2017-01-01

A decline in response rates in traditional household surveys, combined with increased internet coverage and decreased research budgets, has resulted in increased attractiveness of web survey research designs based on purposive and voluntary opt-in sampling strategies. In the study of hidden or stigmatised behaviours, such as cannabis use, web survey methods are increasingly common. However, opt-in web surveys are often heavily criticised due to their lack of sampling frame and unknown representativeness. In this article, we outline the current state of the debate about the relevance of pursuing representativeness, the state of probability sampling methods, and the utility of non-probability, web survey methods especially for accessing hidden or minority populations. Our article has two aims: (1) to present a comprehensive description of the methodology we use at Global Drug Survey (GDS), an annual cross-sectional web survey and (2) to compare the age and sex distributions of cannabis users who voluntarily completed (a) a household survey or (b) a large web-based purposive survey (GDS), across three countries: Australia, the United States, and Switzerland. We find that within each set of country comparisons, the demographic distributions among recent cannabis users are broadly similar, demonstrating that the age and sex distributions of those who volunteer to be surveyed are not vastly different between these non-probability and probability methods. We conclude that opt-in web surveys of hard-to-reach populations are an efficient way of gaining in-depth understanding of stigmatised behaviours and are appropriate, as long as they are not used to estimate drug use prevalence of the general population. PMID:28924351

Heuristic-driven graph wavelet modeling of complex terrain

NASA Astrophysics Data System (ADS)

Cioacǎ, Teodor; Dumitrescu, Bogdan; Stupariu, Mihai-Sorin; Pǎtru-Stupariu, Ileana; Nǎpǎrus, Magdalena; Stoicescu, Ioana; Peringer, Alexander; Buttler, Alexandre; Golay, François

2015-03-01

We present a novel method for building a multi-resolution representation of large digital surface models. The surface points coincide with the nodes of a planar graph which can be processed using a critically sampled, invertible lifting scheme. To drive the lazy wavelet node partitioning, we employ an attribute aware cost function based on the generalized quadric error metric. The resulting algorithm can be applied to multivariate data by storing additional attributes at the graph's nodes. We discuss how the cost computation mechanism can be coupled with the lifting scheme and examine the results by evaluating the root mean square error. The algorithm is experimentally tested using two multivariate LiDAR sets representing terrain surface and vegetation structure with different sampling densities.

Electrochemical Biosensors for Rapid Detection of Foodborne Salmonella: A Critical Overview

PubMed Central

Cinti, Stefano; Volpe, Giulia; Piermarini, Silvia; Delibato, Elisabetta; Palleschi, Giuseppe

2017-01-01

Salmonella has represented the most common and primary cause of food poisoning in many countries for at least over 100 years. Its detection is still primarily based on traditional microbiological culture methods which are labor-intensive, extremely time consuming, and not suitable for testing a large number of samples. Accordingly, great efforts to develop rapid, sensitive and specific methods, easy to use, and suitable for multi-sample analysis, have been made and continue. Biosensor-based technology has all the potentialities to meet these requirements. In this paper, we review the features of the electrochemical immunosensors, genosensors, aptasensors and phagosensors developed in the last five years for Salmonella detection, focusing on the critical aspects of their application in food analysis. PMID:28820458

Development of a mobile system based on laser-induced breakdown spectroscopy and dedicated to in situ analysis of polluted soils

NASA Astrophysics Data System (ADS)

Bousquet, B.; Travaillé, G.; Ismaël, A.; Canioni, L.; Michel-Le Pierrès, K.; Brasseur, E.; Roy, S.; le Hecho, I.; Larregieu, M.; Tellier, S.; Potin-Gautier, M.; Boriachon, T.; Wazen, P.; Diard, A.; Belbèze, S.

2008-10-01

Principal Components Analysis (PCA) is successfully applied to the full laser-induced breakdown spectroscopy (LIBS) spectra of soil samples, defining classes according to the concentrations of the major elements. The large variability of the LIBS data is related to the heterogeneity of the samples and the representativeness of the data is finally discussed. Then, the development of a mobile LIBS system dedicated to the in-situ analysis of soils polluted by heavy metals is described. Based on the use of ten-meter long optical fibers, the mobile system allows deported measurements. Finally, the laser-assisted drying process studied by the use of a customized laser has not been retained to overcome the problem of moisture.

Moonrise: Sampling the South Pole-Aitken Basin to Address Problems of Solar System Significance

NASA Technical Reports Server (NTRS)

Zeigler, R. A.; Jolliff, B. L.; Korotev, R. L.; Shearer, C. K.

2016-01-01

A mission to land in the giant South Pole-Aitken (SPA) Basin on the Moon's southern farside and return a sample to Earth for analysis is a high priority for Solar System Science. Such a sample would be used to determine the age of the SPA impact; the chronology of the basin, including the ages of basins and large impacts within SPA, with implications for early Solar System dynamics and the magmatic history of the Moon; the age and composition of volcanic rocks within SPA; the origin of the thorium signature of SPA with implications for the origin of exposed materials and thermal evolution of the Moon; and possibly the magnetization that forms a strong anomaly especially evident in the northern parts of the SPA basin. It is well known from studies of the Apollo regolith that rock fragments found in the regolith form a representative collection of many different rock types delivered to the site by the impact process (Fig. 1). Such samples are well documented to contain a broad suite of materials that reflect both the local major rock formations, as well as some exotic materials from far distant sources. Within the SPA basin, modeling of the impact ejection process indicates that regolith would be dominated by SPA substrate, formed at the time of the SPA basin-forming impact and for the most part moved around by subsequent impacts. Consistent with GRAIL data, the SPA impact likely formed a vast melt body tens of km thick that took perhaps several million years to cool, but that nonetheless represents barely an instant in geologic time that should be readily apparent through integrated geochronologic studies involving multiple chronometers. It is anticipated that a statistically significant number of age determinations would yield not only the age of SPA but also the age of several prominent nearby basins and large craters within SPA. This chronology would provide a contrast to the Imbrium-dominated chronology of the nearside Apollo samples and an independent test of the timing of the lunar cataclysm.

Sutorius: a new genus for Boletus eximius.

PubMed

Halling, Roy E; Nuhn, Mitchell; Fechner, Nigel A; Osmundson, Todd W; Soytong, Kasem; Arora, David; Hibbett, David S; Binder, Manfred

2012-01-01

Sutorius is described as a new genus of Boletaceae to accommodate Boletus robustus originally named illegitimately by C.C. Frost from eastern North America. The legitimate name, Boletus eximius, provided by C.H. Peck, has been used since for a dark purple to chocolate brown bolete with finely scaly stipe and reddish brown spore deposit. This iconic taxon has been documented on five continents. Despite the straightforward species identification from morphology, the interpretation of stipe macro-morphology and spore color has led to equivocal generic placement. Phylogenetic analyses of genes encoding large subunit rRNA and translation elongation factor 1α confirm Sutorius as a unique generic lineage in the Boletaceae. Two species are recognized based on multiple accessions: S. eximius, represented by collections from North America, Costa Rica, Guyana, Indonesia and Japan (molecular data are lacking for only the Guyanan and Japanese material); and S. australiensis, represented by material from Queensland, Australia. Additional collections from Zambia and Thailand represent independent lineages, but sampling is insufficient to describe new species for these entities.

Detection and Characterization of Circulating Tumour Cells from Frozen Peripheral Blood Mononuclear Cells

PubMed Central

Lu, David; Graf, Ryon P.; Harvey, Melissa; Madan, Ravi A.; Heery, Christopher; Marte, Jennifer; Beasley, Sharon; Tsang, Kwong Y.; Krupa, Rachel; Louw, Jessica; Wahl, Justin; Bales, Natalee; Landers, Mark; Marrinucci, Dena; Schlom, Jeffrey; Gulley, James L.; Dittamore, Ryan

2015-01-01

Retrospective analysis of patient tumour samples is a cornerstone of clinical research. CTC biomarker characterization offers a non-invasive method to analyse patient samples. However, current CTC technologies require prospective blood collection, thereby reducing the ability to utilize archived clinical cohorts with long-term outcome data. We sought to investigate CTC recovery from frozen, archived patient PBMC pellets. Matched samples from both mCRPC patients and mock samples, which were prepared by spiking healthy donor blood with cultured prostate cancer cell line cells, were processed “fresh” via Epic CTC Platform or from “frozen” PBMC pellets. Samples were analysed for CTC enumeration and biomarker characterization via immunofluorescent (IF) biomarkers, fluorescence in-situ hybridization (FISH) and CTC morphology. In the frozen patient PMBC samples, the median CTC recovery was 18%, compared to the freshly processed blood. However, abundance and localization of cytokeratin (CK) and androgen receptor (AR) protein, as measured by IF, were largely concordant between the fresh and frozen CTCs. Furthermore, a FISH analysis of PTEN loss showed high concordance in fresh vs. frozen. The observed data indicate that CTC biomarker characterization from frozen archival samples is feasible and representative of prospectively collected samples. PMID:28936240

40 CFR 141.73 - Filtration.

Code of Federal Regulations, 2014 CFR

2014-07-01

... turbidity level of representative samples of a system's filtered water must be less than or equal to 0.5 NTU....74 (a)(1) and (c)(1). (2) The turbidity level of representative samples of a system's filtered water... filtration, the turbidity level of representative samples of a system's filtered water must be less than or...

TomoMiner and TomoMinerCloud: A software platform for large-scale subtomogram structural analysis

PubMed Central

Frazier, Zachary; Xu, Min; Alber, Frank

2017-01-01

SUMMARY Cryo-electron tomography (cryoET) captures the 3D electron density distribution of macromolecular complexes in close to native state. With the rapid advance of cryoET acquisition technologies, it is possible to generate large numbers (>100,000) of subtomograms, each containing a macromolecular complex. Often, these subtomograms represent a heterogeneous sample due to variations in structure and composition of a complex in situ form or because particles are a mixture of different complexes. In this case subtomograms must be classified. However, classification of large numbers of subtomograms is a time-intensive task and often a limiting bottleneck. This paper introduces an open source software platform, TomoMiner, for large-scale subtomogram classification, template matching, subtomogram averaging, and alignment. Its scalable and robust parallel processing allows efficient classification of tens to hundreds of thousands of subtomograms. Additionally, TomoMiner provides a pre-configured TomoMinerCloud computing service permitting users without sufficient computing resources instant access to TomoMiners high-performance features. PMID:28552576

Characterizing porosity of selected Early Palaeozoic shales from the Baltic Basin: organic petrology, gas adsorption and WIP and KIP approach.

NASA Astrophysics Data System (ADS)

Słomski, Piotr; Mastalerz, Maria; Szczepański, Jacek; Derkowski, Arkadiusz; Topór, Tomasz

2017-04-01

The porosity in the selected Ordovician and Silurian mudstones from the Baltic Basin collected from three wells (W1, M1, B1 and O3) was examined in a suite of 78 samples representing the Kopalino, Sasino, Prabuty, Pasłęk (including Jantar Member) and Pelplin Formations. Organic petrology, mineral composition along with N2 low-pressure adsorption (NLPA), water and kerosene immersion porosimetry (WIP and KIP, respectively) as well as image analysis techniques were used to determine pore volumes, pore sizes and pore-size distributions and to evaluate factors controlling porosity. The majority of the investigated samples represent argillaceous mudstones. Only a few samples from O3 and W1 are different lithologically and represent siliceous-argillaceous, calcareous, or calcareous-argillicaous mudstones. The samples are characterized by total organic carbon (TOC) content ranging from 0.13 to 7.20 wt. % and vitrinite reflectance (Ro) ranging from 1.02 to 1.22%, indicating late mature rocks within condensate - wet gas window. Total porosity measured using WIP is in the range from 4.6 % to 10 %, while KIP gave values from 1.5 % to 8.9 %. NLPA technique on the 75 µm size fraction revealed that mesopores area is in the range from 10.59 to 34.34 m2/g, while mesopores volume ranges from 0.024 to 0.062 cm3/g. Correlation between mesopores surface area and Ro is weak, but in general the surface area of mesopores is the largest in the least mature samples. Moreover, as indicated by gas adsorption data, both pores greater than 30 nm and smaller than 4 nm are important contributors to the total mesoporess surface area. In general, rather weak correlation between different mudstone constituents (including kerogen types) and porosity measured by means of various techniques (WIP, KIP and NLPA) reveal that there is no single factor controlling porosity in the investigated suite of samples. This conclusion is also confirmed by image analysis performed on large-scale high-resolution BSE images for selected representative samples. However, for mesopores, the dominant contribution comes from organic matter for the Jantar, Prabuty and Sasino Formations, as indicated by NLPA technique. Furthermore, importance of clay minerals for macropore volume is indicated by WIP and KIP technique. Acknowledgments: the study was supported from grant SHALESEQ (No PL12-0109) and SHALEMECH (No BG2/ShaleMech/14) funded by the National Centre for Research and Development.

Pb-Pb systematics of lunar rocks: differentiation, magmatic and impact history of the Moon

NASA Astrophysics Data System (ADS)

Nemchin, A.; Martin, W.; Norman, M. D.; Snape, J.; Bellucci, J. J.; Grange, M.

2016-12-01

Two independent decay chains in U-Pb system allow the determination of both ages and initial isotope compositions by analyzing only Pb in the samples. A typical Pb analysis represents a mixture of radiogenic Pb produced from the in situ U decay, initial Pb and laboratory contamination. Utilizing the ability of ion probes to analyse 10-30 micrometer-sized spots in the samples while avoiding fractures and other imperfections that commonly host contamination, permits extraction of pure lunar Pb compositions from the three component mixtures. This results in both accurate and precise ages of the rocks and their initial compositions. Lunar Mare and KREEP basalts postdating the major lunar bombardment are likely to represent such three component mixtures and are therefore appropriate for this approach, also giving an opportunity to investigate Pb evolution in their sources. A source evolution model constrained using available data indicates a major differentiation on the Moon at 4376±18 Ma and very radiogenic lunar mantle at this time. This age is likely to reflect the mean time of KREEP formation during the last stage of Magma Ocean differentiation. Rocks older than about 3.9 Ga are more complex than basalts and may include an extra Pb component, if modified by impacts. An example of this is presented by Pb-Pb data obtained for the anorthosite sample 62236, where the age of the rock is determined as 4367±29 Ma from analyses of CPx lamellae inside the large Opx grains: however large plagioclase crystals do not contain Pb in quantities sufficient for ion probe analysis, precluding determination of the initial Pb composition of the sample. Most of Pb is found in the brecciated parts of the anorthosite between the large grains. The composition of this Pb is similar to the initial Pb of 3909±17 Ma Apollo 16 breccia 66095, suggesting that is was injected into the anorthosite during a 3.9 Ga impact. Similar ca 3.9 Ga ages were determined for 1-2 millimeter size feldspathic clasts from several Apollo 14 breccias, where they are likely to date Pb homogenization during the Imbrium impact. Combined with U-Pb data obtained previously using U-bearing minerals such as zircon and phosphates, the new Pb-Pb data sets open an opportunity for a detailed chronological and isotopic investigation of lunar differentiation, magmatic evolution and impact history.

Online Recruitment: Feasibility, Cost, and Representativeness in a Study of Postpartum Women.

PubMed

Leach, Liana S; Butterworth, Peter; Poyser, Carmel; Batterham, Philip J; Farrer, Louise M

2017-03-08

Online recruitment is feasible, low-cost, and can provide high-quality epidemiological data. However, little is known about the feasibility of recruiting postpartum women online, or sample representativeness. The current study investigates the feasibility of recruiting a population of postpartum women online for health research and examines sample representativeness. Two samples of postpartum women were compared: those recruited online as participants in a brief survey of new mothers (n=1083) and those recruited face-to-face as part of a nationally representative study (n=579). Sociodemographic, general health, and mental health characteristics were compared between the two samples. Obtaining a sample of postpartum women online for health research was highly efficient and low-cost. The online sample over-represented those who were younger (aged 25-29 years), were in a de facto relationship, had higher levels of education, spoke only English at home, and were first-time mothers. Members of the online sample were significantly more likely to have poor self-rated health and poor mental health than the nationally representative sample. Health differences remained after adjusting for sociodemographic differences. Potential exists for feasible and low-cost e-epidemiological research with postpartum populations; however, researchers should consider the potential influence of sample nonrepresentativeness. ©Liana S Leach, Peter Butterworth, Carmel Poyser, Philip J Batterham, Louise M Farrer. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 08.03.2017.

Frequent Detection and Genetic Diversity of Human Bocavirus in Urban Sewage Samples.

PubMed

Iaconelli, M; Divizia, M; Della Libera, S; Di Bonito, P; La Rosa, Giuseppina

2016-12-01

The prevalence and genetic diversity of human bocaviruses (HBoVs) in sewage water samples are largely unknown. In this study, 134 raw sewage samples from 25 wastewater treatment plants (WTPs) in Italy were analyzed by nested PCR and sequencing using species-specific primer pairs and broad-range primer pairs targeting the capsid proteins VP1/VP2. A large number of samples (106, 79.1 %) were positive for HBoV. Out of these, 49 were classified as HBoV species 2, and 27 as species 3. For the remaining 30 samples, sequencing results showed mixed electropherograms. By cloning PCR amplicons and sequencing, we confirmed the copresence of species 2 and 3 in 29 samples and species 2 and 4 in only one sample. A real-time PCR assay was also performed, using a newly designed TaqMan assay, for quantification of HBoVs in sewage water samples. Viral load quantification ranged from 5.51E+03 to 1.84E+05 GC/L (mean value 4.70E+04 GC/L) for bocavirus 2 and from 1.89E+03 to 1.02E+05 GC/L (mean value 2.27E+04 GC/L) for bocavirus 3. The wide distribution of HBoV in sewages suggests that this virus is common in the population, and the most prevalent are the species 2 and 3. HBoV-4 was also found, representing the first detection of this species in Italy. Although there is no indication of waterborne transmission for HBoV, the significant presence in sewage waters suggests that HBoV may spread to other water environments, and therefore, a potential role of water in the HBoV transmission should not be neglected.

Evaluation of a Class of Simple and Effective Uncertainty Methods for Sparse Samples of Random Variables and Functions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Romero, Vicente; Bonney, Matthew; Schroeder, Benjamin

When very few samples of a random quantity are available from a source distribution of unknown shape, it is usually not possible to accurately infer the exact distribution from which the data samples come. Under-estimation of important quantities such as response variance and failure probabilities can result. For many engineering purposes, including design and risk analysis, we attempt to avoid under-estimation with a strategy to conservatively estimate (bound) these types of quantities -- without being overly conservative -- when only a few samples of a random quantity are available from model predictions or replicate experiments. This report examines a classmore » of related sparse-data uncertainty representation and inference approaches that are relatively simple, inexpensive, and effective. Tradeoffs between the methods' conservatism, reliability, and risk versus number of data samples (cost) are quantified with multi-attribute metrics use d to assess method performance for conservative estimation of two representative quantities: central 95% of response; and 10 -4 probability of exceeding a response threshold in a tail of the distribution. Each method's performance is characterized with 10,000 random trials on a large number of diverse and challenging distributions. The best method and number of samples to use in a given circumstance depends on the uncertainty quantity to be estimated, the PDF character, and the desired reliability of bounding the true value. On the basis of this large data base and study, a strategy is proposed for selecting the method and number of samples for attaining reasonable credibility levels in bounding these types of quantities when sparse samples of random variables or functions are available from experiments or simulations.« less

ACQUISITION OF REPRESENTATIVE GROUND WATER QUALITY SAMPLES FOR METALS

EPA Science Inventory

R.S. Kerr Environmental Research Laboratory (RSKERL) personnel have evaluated sampling procedures for the collection of representative, accurate, and reproducible ground water quality samples for metals for the past four years. Intensive sampling research at three different field...

How college students conceptualize and practice responsible drinking.

PubMed

Barry, Adam E; Goodson, Patricia

2011-01-01

This study sought to employ a mixed-methods approach to (a) qualitatively explore responsible drinking beliefs and behaviors among a sample of college students, and (b) quantitatively assess the prevalence of those behaviors. Convenience samples, drawn from currently enrolled students attending a large public university in Texas, comprised 13 participants in the qualitative phase and a random sample of 729 students for the quantitative phase. A partially mixed sequential dominant status design (qual → QUAN) was employed. PARTICIPANTS associated 7 distinct themes with drinking responsibly; however, embedded inside these themes were numerous potentially harmful elements. Quantitative findings supported the qualitative themes, also highlighting gender and ethnic differences. Males believed responsible drinking behaviors should occur with significantly less frequency than females, whereas Whites attached less relative necessity to certain responsible drinking behaviors. This study represents an initial attempt to determine specific, evidence-based characteristics of responsible drinking.

Atomistic study of two-level systems in amorphous silica

NASA Astrophysics Data System (ADS)

Damart, T.; Rodney, D.

2018-01-01

Internal friction is analyzed in an atomic-scale model of amorphous silica. The potential energy landscape of more than 100 glasses is explored to identify a sample of about 700 two-level systems (TLSs). We discuss the properties of TLSs, particularly their energy asymmetry and barrier as well as their deformation potential, computed as longitudinal and transverse averages of the full deformation potential tensors. The discrete sampling is used to predict dissipation in the classical regime. Comparison with experimental data shows a better agreement with poorly relaxed thin films than well relaxed vitreous silica, as expected from the large quench rates used to produce numerical glasses. The TLSs are categorized in three types that are shown to affect dissipation in different temperature ranges. The sampling is also used to discuss critically the usual approximations employed in the literature to represent the statistical properties of TLSs.

Lipid Vesicle Shape Analysis from Populations Using Light Video Microscopy and Computer Vision

PubMed Central

Zupanc, Jernej; Drašler, Barbara; Boljte, Sabina; Kralj-Iglič, Veronika; Iglič, Aleš; Erdogmus, Deniz; Drobne, Damjana

2014-01-01

We present a method for giant lipid vesicle shape analysis that combines manually guided large-scale video microscopy and computer vision algorithms to enable analyzing vesicle populations. The method retains the benefits of light microscopy and enables non-destructive analysis of vesicles from suspensions containing up to several thousands of lipid vesicles (1–50 µm in diameter). For each sample, image analysis was employed to extract data on vesicle quantity and size distributions of their projected diameters and isoperimetric quotients (measure of contour roundness). This process enables a comparison of samples from the same population over time, or the comparison of a treated population to a control. Although vesicles in suspensions are heterogeneous in sizes and shapes and have distinctively non-homogeneous distribution throughout the suspension, this method allows for the capture and analysis of repeatable vesicle samples that are representative of the population inspected. PMID:25426933

Reaching multi-nanosecond timescales in combined QM/MM molecular dynamics simulations through parallel horsetail sampling.

PubMed

Martins-Costa, Marilia T C; Ruiz-López, Manuel F

2017-04-15

We report an enhanced sampling technique that allows to reach the multi-nanosecond timescale in quantum mechanics/molecular mechanics molecular dynamics simulations. The proposed technique, called horsetail sampling, is a specific type of multiple molecular dynamics approach exhibiting high parallel efficiency. It couples a main simulation with a large number of shorter trajectories launched on independent processors at periodic time intervals. The technique is applied to study hydrogen peroxide at the water liquid-vapor interface, a system of considerable atmospheric relevance. A total simulation time of a little more than 6 ns has been attained for a total CPU time of 5.1 years representing only about 20 days of wall-clock time. The discussion of the results highlights the strong influence of the solvation effects at the interface on the structure and the electronic properties of the solute. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Tongue Color Analysis for Medical Application

PubMed Central

Wang, Xingzheng; You, Jane

2013-01-01

An in-depth systematic tongue color analysis system for medical applications is proposed. Using the tongue color gamut, tongue foreground pixels are first extracted and assigned to one of 12 colors representing this gamut. The ratio of each color for the entire image is calculated and forms a tongue color feature vector. Experimenting on a large dataset consisting of 143 Healthy and 902 Disease (13 groups of more than 10 samples and one miscellaneous group), a given tongue sample can be classified into one of these two classes with an average accuracy of 91.99%. Further testing showed that Disease samples can be split into three clusters, and within each cluster most if not all the illnesses are distinguished from one another. In total 11 illnesses have a classification rate greater than 70%. This demonstrates a relationship between the state of the human body and its tongue color. PMID:23737824

Depressive Symptoms of Chinese Children: Prevalence and Correlated Factors among Subgroups.

PubMed

Zhou, Mi; Zhang, Guangsheng; Rozelle, Scott; Kenny, Kaleigh; Xue, Hao

2018-02-07

Economic growth and socioeconomic changes have transformed nearly every aspect of childhood in China, and many are worried by the increasing prevalence of mental health issues among children, particularly depression. To provide insight into the distribution of depressive symptoms among children in China and identify vulnerable groups, we use data from the 2012 China Family Panel Survey (CFPS), a survey that collected data from a large, nationally representative sample of the Chinese population. Using the CFPS data, we construct a sample of 2679 children aged 10-15 years old from 25 provinces in China. According to our results, the incidence of depression varies by geographic area. Specifically, we find that rates of depressive symptoms are significantly lower in urban areas (14% of sample children) than in rural areas (23% of sample children). Our results also show that children from ethnic minorities, from poorer families, and whose parents are depressed are more likely to be depressed than other children. In contrast, we find that depressive symptoms do not vary by gender.

Methodology for Augmenting Existing Paths with Additional Parallel Transects

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilson, John E.

2013-09-30

Visual Sample Plan (VSP) is sample planning software that is used, among other purposes, to plan transect sampling paths to detect areas that were potentially used for munition training. This module was developed for application on a large site where existing roads and trails were to be used as primary sampling paths. Gap areas between these primary paths needed to found and covered with parallel transect paths. These gap areas represent areas on the site that are more than a specified distance from a primary path. These added parallel paths needed to optionally be connected together into a single path—themore » shortest path possible. The paths also needed to optionally be attached to existing primary paths, again with the shortest possible path. Finally, the process must be repeatable and predictable so that the same inputs (primary paths, specified distance, and path options) will result in the same set of new paths every time. This methodology was developed to meet those specifications.« less

Virulence-associated and antibiotic resistance genes of microbial populations in cattle feces analyzed using a metagenomic approach.

PubMed

Durso, Lisa M; Harhay, Gregory P; Bono, James L; Smith, Timothy P L

2011-02-01

The bovine fecal microbiota impacts human food safety as well as animal health. Although the bacteria of cattle feces have been well characterized using culture-based and culture-independent methods, techniques have been lacking to correlate total community composition with community function. We used high throughput sequencing of total DNA extracted from fecal material to characterize general community composition and examine the repertoire of microbial genes present in beef cattle feces, including genes associated with antibiotic resistance and bacterial virulence. Results suggest that traditional 16S sequencing using "universal" primers to generate full-length sequence may under represent Acitinobacteria and Proteobacteria. Over eight percent (8.4%) of the sequences from our beef cattle fecal pool sample could be categorized as virulence genes, including a suite of genes associated with resistance to antibiotic and toxic compounds (RATC). This is a higher proportion of virulence genes found in Sargasso sea, chicken cecum, and cow rumen samples, but comparable to the proportion found in Antarctic marine derived lake, human fecal, and farm soil samples. The quantitative nature of metagenomic data, combined with the large number of RATC classes represented in samples from widely different habitats indicates that metagenomic data can be used to track relative amounts of antibiotic resistance genes in individual animals over time. Consequently, these data can be used to generate sample-specific and temporal antibiotic resistance gene profiles to facilitate an understanding of the ecology of the microbial communities in each habitat as well as the epidemiology of antibiotic resistant gene transport between and among habitats. Published by Elsevier B.V.

Peer-relationship-problems account for quality of life impairments in pediatric psoriasis.

PubMed

Matterne, Uwe; Apfelbacher, Christian

2016-05-01

Most research on HRQoL-impairments in psoriasis has been conducted in adult patients, small pediatric patient samples or samples not representative of the pediatric population at large. We thus aimed to comprehensively describe HRQoL in pediatric psoriasis compared to psoriasis-free children and adolescents, identify domains most commonly affected and analyze its impact on HRQoL while controlling for important other predictors of HRQoL in a representative pediatric sample. The impact of lifetime-prevalence of psoriasis on total and subscale HRQoL was analyzed by complex sample general linear models alone and adjusted for sociodemographic and clinical variables in a population-based sample (n=6518) of children and adolescents aged 11-17. Total HRQoL and the physical domain were significantly affected by lifetime-psoriasis in univariate analysis. In multivariate analyses, lifetime-psoriasis significantly impacted on total HRQoL and the subscale 'quality of relationships with friends/peers'. Although substantial amounts of variance in HRQoL were explained by mental health, independent effects of lifetime-psoriasis remained after adjustment for this covariate. Total explained variance in total HRQoL was 20%. Our findings suggest psoriasis to be a significant burden as it affects HRQoL even when controlling for mental health. Most of this effect appears to be driven by perceived impairments in the quality of relationship with friends/peers. How this exactly occurs needs to be explored in future research. Meanwhile clinicians need to be more attentive to this effect of psoriasis. Copyright © 2016 Elsevier Inc. All rights reserved.

National Databases for Neurosurgical Outcomes Research: Options, Strengths, and Limitations.

PubMed

Karhade, Aditya V; Larsen, Alexandra M G; Cote, David J; Dubois, Heloise M; Smith, Timothy R

2017-08-05

Quality improvement, value-based care delivery, and personalized patient care depend on robust clinical, financial, and demographic data streams of neurosurgical outcomes. The neurosurgical literature lacks a comprehensive review of large national databases. To assess the strengths and limitations of various resources for outcomes research in neurosurgery. A review of the literature was conducted to identify surgical outcomes studies using national data sets. The databases were assessed for the availability of patient demographics and clinical variables, longitudinal follow-up of patients, strengths, and limitations. The number of unique patients contained within each data set ranged from thousands (Quality Outcomes Database [QOD]) to hundreds of millions (MarketScan). Databases with both clinical and financial data included PearlDiver, Premier Healthcare Database, Vizient Clinical Data Base and Resource Manager, and the National Inpatient Sample. Outcomes collected by databases included patient-reported outcomes (QOD); 30-day morbidity, readmissions, and reoperations (National Surgical Quality Improvement Program); and disease incidence and disease-specific survival (Surveillance, Epidemiology, and End Results-Medicare). The strengths of large databases included large numbers of rare pathologies and multi-institutional nationally representative sampling; the limitations of these databases included variable data veracity, variable data completeness, and missing disease-specific variables. The improvement of existing large national databases and the establishment of new registries will be crucial to the future of neurosurgical outcomes research. Copyright © 2017 by the Congress of Neurological Surgeons

Xenosurveillance reflects traditional sampling techniques for the identification of human pathogens: A comparative study in West Africa

PubMed Central

Fakoli, Lawrence S.; Bolay, Kpehe; Bolay, Fatorma K.; Diclaro, Joseph W.; Brackney, Doug E.; Stenglein, Mark D.; Ebel, Gregory D.

2018-01-01

Background Novel surveillance strategies are needed to detect the rapid and continuous emergence of infectious disease agents. Ideally, new sampling strategies should be simple to implement, technologically uncomplicated, and applicable to areas where emergence events are known to occur. To this end, xenosurveillance is a technique that makes use of blood collected by hematophagous arthropods to monitor and identify vertebrate pathogens. Mosquitoes are largely ubiquitous animals that often exist in sizable populations. As well, many domestic or peridomestic species of mosquitoes will preferentially take blood-meals from humans, making them a unique and largely untapped reservoir to collect human blood. Methodology/Principal findings We sought to take advantage of this phenomenon by systematically collecting blood-fed mosquitoes during a field trail in Northern Liberia to determine whether pathogen sequences from blood engorged mosquitoes accurately mirror those obtained directly from humans. Specifically, blood was collected from humans via finger-stick and by aspirating bloodfed mosquitoes from the inside of houses. Shotgun metagenomic sequencing of RNA and DNA derived from these specimens was performed to detect pathogen sequences. Samples obtained from xenosurveillance and from finger-stick blood collection produced a similar number and quality of reads aligning to two human viruses, GB virus C and hepatitis B virus. Conclusions/Significance This study represents the first systematic comparison between xenosurveillance and more traditional sampling methodologies, while also demonstrating the viability of xenosurveillance as a tool to sample human blood for circulating pathogens. PMID:29561834

Xenosurveillance reflects traditional sampling techniques for the identification of human pathogens: A comparative study in West Africa.

PubMed

Fauver, Joseph R; Weger-Lucarelli, James; Fakoli, Lawrence S; Bolay, Kpehe; Bolay, Fatorma K; Diclaro, Joseph W; Brackney, Doug E; Foy, Brian D; Stenglein, Mark D; Ebel, Gregory D

2018-03-01

Novel surveillance strategies are needed to detect the rapid and continuous emergence of infectious disease agents. Ideally, new sampling strategies should be simple to implement, technologically uncomplicated, and applicable to areas where emergence events are known to occur. To this end, xenosurveillance is a technique that makes use of blood collected by hematophagous arthropods to monitor and identify vertebrate pathogens. Mosquitoes are largely ubiquitous animals that often exist in sizable populations. As well, many domestic or peridomestic species of mosquitoes will preferentially take blood-meals from humans, making them a unique and largely untapped reservoir to collect human blood. We sought to take advantage of this phenomenon by systematically collecting blood-fed mosquitoes during a field trail in Northern Liberia to determine whether pathogen sequences from blood engorged mosquitoes accurately mirror those obtained directly from humans. Specifically, blood was collected from humans via finger-stick and by aspirating bloodfed mosquitoes from the inside of houses. Shotgun metagenomic sequencing of RNA and DNA derived from these specimens was performed to detect pathogen sequences. Samples obtained from xenosurveillance and from finger-stick blood collection produced a similar number and quality of reads aligning to two human viruses, GB virus C and hepatitis B virus. This study represents the first systematic comparison between xenosurveillance and more traditional sampling methodologies, while also demonstrating the viability of xenosurveillance as a tool to sample human blood for circulating pathogens.

Vapor-phase concentrations of PAHs and their derivatives determined in a large city: correlations with their atmospheric aerosol concentrations.

PubMed

Barrado, Ana Isabel; García, Susana; Sevillano, Marisa Luisa; Rodríguez, Jose Antonio; Barrado, Enrique

2013-11-01

Thirteen PAHs, five nitro-PAHs and two hydroxy-PAHs were determined in 55 vapor-phase samples collected in a suburban area of a large city (Madrid, Spain), from January 2008 to February 2009. The data obtained revealed correlations between the concentrations of these compounds and a series of meteorological factors (e.g., temperature, atmospheric pressure) and physical-chemical factors (e.g., nitrogen and sulfur oxides). As a consequence, seasonal trends were observed in the atmospheric pollutants. A "mean sample" for the 14-month period would contain a total PAH concentration of 13835±1625 pg m(-3) and 122±17 pg m(-3) of nitro-PAHs. When the data were stratified by season, it emerged that a representative sample of the coldest months would contain 18900±2140 pg m(-3) of PAHs and 150±97 pg m(-3) of nitro-PAHs, while in an average sample collected in the warmest months, these values drop to 9293±1178 pg m(-3) for the PAHs and to 97±13 pg m(-3) for the nitro-PAHs. Total vapor phase concentrations of PAHs were one order of magnitude higher than concentrations detected in atmospheric aerosol samples collected on the same dates. Total nitro-PAH concentrations were comparable to their aerosol concentrations whereas vapor phase OH-PAHs were below their limits of the detection, indicating these were trapped in airborne particles. Copyright © 2013 Elsevier Ltd. All rights reserved.

Domain-Adapted Convolutional Networks for Satellite Image Classification: A Large-Scale Interactive Learning Workflow

DOE PAGES

Lunga, Dalton D.; Yang, Hsiuhan Lexie; Reith, Andrew E.; ...

2018-02-06

Satellite imagery often exhibits large spatial extent areas that encompass object classes with considerable variability. This often limits large-scale model generalization with machine learning algorithms. Notably, acquisition conditions, including dates, sensor position, lighting condition, and sensor types, often translate into class distribution shifts introducing complex nonlinear factors and hamper the potential impact of machine learning classifiers. Here, this article investigates the challenge of exploiting satellite images using convolutional neural networks (CNN) for settlement classification where the class distribution shifts are significant. We present a large-scale human settlement mapping workflow based-off multiple modules to adapt a pretrained CNN to address themore » negative impact of distribution shift on classification performance. To extend a locally trained classifier onto large spatial extents areas we introduce several submodules: First, a human-in-the-loop element for relabeling of misclassified target domain samples to generate representative examples for model adaptation; second, an efficient hashing module to minimize redundancy and noisy samples from the mass-selected examples; and third, a novel relevance ranking module to minimize the dominance of source example on the target domain. The workflow presents a novel and practical approach to achieve large-scale domain adaptation with binary classifiers that are based-off CNN features. Experimental evaluations are conducted on areas of interest that encompass various image characteristics, including multisensors, multitemporal, and multiangular conditions. Domain adaptation is assessed on source–target pairs through the transfer loss and transfer ratio metrics to illustrate the utility of the workflow.« less

Domain-Adapted Convolutional Networks for Satellite Image Classification: A Large-Scale Interactive Learning Workflow

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lunga, Dalton D.; Yang, Hsiuhan Lexie; Reith, Andrew E.

Satellite imagery often exhibits large spatial extent areas that encompass object classes with considerable variability. This often limits large-scale model generalization with machine learning algorithms. Notably, acquisition conditions, including dates, sensor position, lighting condition, and sensor types, often translate into class distribution shifts introducing complex nonlinear factors and hamper the potential impact of machine learning classifiers. Here, this article investigates the challenge of exploiting satellite images using convolutional neural networks (CNN) for settlement classification where the class distribution shifts are significant. We present a large-scale human settlement mapping workflow based-off multiple modules to adapt a pretrained CNN to address themore » negative impact of distribution shift on classification performance. To extend a locally trained classifier onto large spatial extents areas we introduce several submodules: First, a human-in-the-loop element for relabeling of misclassified target domain samples to generate representative examples for model adaptation; second, an efficient hashing module to minimize redundancy and noisy samples from the mass-selected examples; and third, a novel relevance ranking module to minimize the dominance of source example on the target domain. The workflow presents a novel and practical approach to achieve large-scale domain adaptation with binary classifiers that are based-off CNN features. Experimental evaluations are conducted on areas of interest that encompass various image characteristics, including multisensors, multitemporal, and multiangular conditions. Domain adaptation is assessed on source–target pairs through the transfer loss and transfer ratio metrics to illustrate the utility of the workflow.« less

Contemporaneous trace and body fossils from a late Pleistocene Lakebed in Victoria, Australia, allow assessment of bias in the fossil record.

PubMed

Camens, Aaron Bruce; Carey, Stephen Paul

2013-01-01

The co-occurrence of vertebrate trace and body fossils within a single geological formation is rare and the probability of these parallel records being contemporaneous (i.e. on or near the same bedding plane) is extremely low. We report here a late Pleistocene locality from the Victorian Volcanic Plains in south-eastern Australia in which demonstrably contemporaneous, but independently accumulated vertebrate trace and body fossils occur. Bite marks from a variety of taxa are also present on the bones. This site provides a unique opportunity to examine the biases of these divergent fossil records (skeletal, footprints and bite marks) that sampled a single fauna. The skeletal record produced the most complete fauna, with the footprint record indicating a markedly different faunal composition with less diversity and the feeding traces suggesting the presence, amongst others, of a predator not represented by either the skeletal or footprint records. We found that the large extinct marsupial predator Thylacoleo was the only taxon apparently represented by all three records, suggesting that the behavioral characteristics of large carnivores may increase the likelihood of their presence being detected within a fossil fauna. In contrast, Diprotodon (the largest-ever marsupial) was represented only by trace fossils at this site and was absent from the site's skeletal record, despite its being a common and easily detected presence in late Pleistocene skeletal fossil faunas elsewhere in Australia. Small mammals absent from the footprint record for the site were represented by skeletal fossils and bite marks on bones.

Contemporaneous Trace and Body Fossils from a Late Pleistocene Lakebed in Victoria, Australia, Allow Assessment of Bias in the Fossil Record

PubMed Central

Camens, Aaron Bruce; Carey, Stephen Paul

2013-01-01

The co-occurrence of vertebrate trace and body fossils within a single geological formation is rare and the probability of these parallel records being contemporaneous (i.e. on or near the same bedding plane) is extremely low. We report here a late Pleistocene locality from the Victorian Volcanic Plains in south-eastern Australia in which demonstrably contemporaneous, but independently accumulated vertebrate trace and body fossils occur. Bite marks from a variety of taxa are also present on the bones. This site provides a unique opportunity to examine the biases of these divergent fossil records (skeletal, footprints and bite marks) that sampled a single fauna. The skeletal record produced the most complete fauna, with the footprint record indicating a markedly different faunal composition with less diversity and the feeding traces suggesting the presence, amongst others, of a predator not represented by either the skeletal or footprint records. We found that the large extinct marsupial predator Thylacoleo was the only taxon apparently represented by all three records, suggesting that the behavioral characteristics of large carnivores may increase the likelihood of their presence being detected within a fossil fauna. In contrast, Diprotodon (the largest-ever marsupial) was represented only by trace fossils at this site and was absent from the site's skeletal record, despite its being a common and easily detected presence in late Pleistocene skeletal fossil faunas elsewhere in Australia. Small mammals absent from the footprint record for the site were represented by skeletal fossils and bite marks on bones. PMID:23301008

A universal reference sample derived from clone vector for improved detection of differential gene expression

PubMed Central

Khan, Rishi L; Gonye, Gregory E; Gao, Guang; Schwaber, James S

2006-01-01

Background Using microarrays by co-hybridizing two samples labeled with different dyes enables differential gene expression measurements and comparisons across slides while controlling for within-slide variability. Typically one dye produces weaker signal intensities than the other often causing signals to be undetectable. In addition, undetectable spots represent a large problem for two-color microarray designs and most arrays contain at least 40% undetectable spots even when labeled with reference samples such as Stratagene's Universal Reference RNAs™. Results We introduce a novel universal reference sample that produces strong signal for all spots on the array, increasing the average fraction of detectable spots to 97%. Maximizing detectable spots on the reference image channel also decreases the variability of microarray data allowing for reliable detection of smaller differential gene expression changes. The reference sample is derived from sequence contained in the parental EST clone vector pT7T3D-Pac and is called vector RNA (vRNA). We show that vRNA can also be used for quality control of microarray printing and PCR product quality, detection of hybridization anomalies, and simplification of spot finding and segmentation tasks. This reference sample can be made inexpensively in large quantities as a renewable resource that is consistent across experiments. Conclusion Results of this study show that vRNA provides a useful universal reference that yields high signal for almost all spots on a microarray, reduces variation and allows for comparisons between experiments and laboratories. Further, it can be used for quality control of microarray printing and PCR product quality, detection of hybridization anomalies, and simplification of spot finding and segmentation tasks. This type of reference allows for detection of small changes in differential expression while reference designs in general allow for large-scale multivariate experimental designs. vRNA in combination with reference designs enable systems biology microarray experiments of small physiologically relevant changes. PMID:16677381

Soot and palynologic analysis of Manson impact-related strata (Upper Cretaceous) of Iowa and South Dakota, USA

USGS Publications Warehouse

Varricchio, D.J.; Raven, R.F.; Wolbach, W.S.; Elsik, W.C.; Witzke, B.J.

2009-01-01

The Campanian Manson impact structure of Iowa represents the best-preserved, large-diameter complex crater within the continental U.S. To assess the timing and potential mode of crater infilling and the possible presence of an impact event horizon, we analyzed samples from both within and distal to the impact structure for their elemental carbon, soot and palynomorphs. Within the impact structure, identifiable soot occurred in fragmented impact breccia and suevite but not in lower impact-melt breccia. Although most of this soot likely represents reworking of material from older Cretaceous marine shales, one high soot concentration occurs with melt material in a Keweenawan Shale-Phanerozoic clast breccia mix. This represents the first association of soot and impact-generated materials within an impact structure and the best sample candidate for Manson impact-generated soot. No palynomorphs occurred in the impact melt breccia. Overlying suevite (Keweenawan Shale clast breccia) of the central peak yielded sparse and thermally altered palynomorphs, indicating deposition prior to full cooling of the crater debris. Presence of easily degraded soot also argues for rapid backfilling of the crater. Distal samples from South Dakota represent the Sharon Springs and Crow Creek members of the Pierre Shale 230 km northwest of the Manson impact structure. Although containing shocked grains, the Crow Creek preserves no soot. In contrast, the Sharon Springs, generally considered as predating the Manson impact, has significant soot quantities. Palynomorphs differ markedly across the unconformity separating the two members with the Crow Creek containing more terrestrial forms, normapolles, and older reworked palynomorphs, consistent with a terrestrial impact to the east. Origin of the Sharon Springs soot remains unclear. Given soot occurrence within four of the five Cretaceous marine units sampled, the relatively shallow, anoxic bottom conditions of the Western Interior Cretaceous Seaway may have simply favored soot preservation. Until a better understanding of the broader occurrence and preservation of soot is achieved, some soot-impact associations will remain ambiguous. ?? 2008 Elsevier Ltd. All rights reserved.

Gut microbial ecology of lizards: insights into diversity in the wild, effects of captivity, variation across gut regions and transmission.

PubMed

Kohl, Kevin D; Brun, Antonio; Magallanes, Melisa; Brinkerhoff, Joshua; Laspiur, Alejandro; Acosta, Juan Carlos; Caviedes-Vidal, Enrique; Bordenstein, Seth R

2017-02-01

Animals maintain complex associations with a diverse microbiota living in their guts. Our understanding of the ecology of these associations is extremely limited in reptiles. Here, we report an in-depth study into the microbial ecology of gut communities in three syntopic and viviparous lizard species (two omnivores: Liolaemus parvus and Liolaemus ruibali and an herbivore: Phymaturus williamsi). Using 16S rRNA gene sequencing to inventory various bacterial communities, we elucidate four major findings: (i) closely related lizard species harbour distinct gut bacterial microbiota that remain distinguishable in captivity; a considerable portion of gut bacterial diversity (39.1%) in nature overlap with that found on plant material, (ii) captivity changes bacterial community composition, although host-specific communities are retained, (iii) faecal samples are largely representative of the hindgut bacterial community and thus represent acceptable sources for nondestructive sampling, and (iv) lizards born in captivity and separated from their mothers within 24 h shared 34.3% of their gut bacterial diversity with their mothers, suggestive of maternal or environmental transmission. Each of these findings represents the first time such a topic has been investigated in lizard hosts. Taken together, our findings provide a foundation for comparative analyses of the faecal and gastrointestinal microbiota of reptile hosts. © 2016 John Wiley & Sons Ltd.

γ-Oryzanol and tocopherol contents in residues of rice bran oil refining.

PubMed

Pestana-Bauer, Vanessa Ribeiro; Zambiazi, Rui C; Mendonça, Carla R B; Beneito-Cambra, Miriam; Ramis-Ramos, Guillermo

2012-10-01

Rice bran oil (RBO) contains significant amounts of the natural antioxidants γ-oryzanol and tocopherols, which are lost to a large degree during oil refining. This results in a number of industrial residues with high contents of these phytochemicals. With the aim of supporting the development of profitable industrial procedures for γ-oryzanol and tocopherol recovery, the contents of these phytochemicals in all the residues produced during RBO refining were evaluated. The samples included residues from the degumming, soap precipitation, bleaching earth filtering, dewaxing and deodorisation distillation steps. The highest phytochemical concentrations were found in the precipitated soap for γ-oryzanol (14.2 mg g(-1), representing 95.3% of total γ-oryzanol in crude RBO), and in the deodorisation distillate for tocopherols (576 mg 100 g(-1), representing 6.7% of total tocopherols in crude RBO). Therefore, among the residues of RBO processing, the deodorisation distillate was the best source of tocopherols. As the soap is further processed for the recovery of fatty acids, samples taken from every step of this secondary process, including hydrosoluble fraction, hydrolysed soap, distillation residue and purified fatty acid fraction, were also analyzed. The distillation residue left after fatty acid recovery from soap was found to be the best source of γ-oryzanol (43.1 mg g(-1), representing 11.5% of total γ-oryzanol in crude RBO). Copyright © 2012 Elsevier Ltd. All rights reserved.

TNO/Centaurs grouping tested with asteroid data sets

NASA Astrophysics Data System (ADS)

Fulchignoni, M.; Birlan, M.; Barucci, M. A.

2001-11-01

Recently, we have discussed the possible subdivision in few groups of a sample of 22 TNO and Centaurs for which the BVRIJ photometry were available (Barucci et al., 2001, A&A, 371,1150). We obtained this results using the multivariate statistics adopted to define the current asteroid taxonomy, namely the Principal Components Analysis and the G-mode method (Tholen & Barucci, 1989, in ASTEROIDS II). How these methods work with a very small statistical sample as the TNO/Centaurs one? Theoretically, the number of degrees of freedom of the sample is correct. In fact it is 88 in our case and have to be larger then 50 to cope with the requirements of the G-mode. Does the random sampling of the small number of members of a large population contain enough information to reveal some structure in the population? We extracted several samples of 22 asteroids out of a data-base of 86 objects of known taxonomic type for which BVRIJ photometry is available from ECAS (Zellner et al. 1985, ICARUS 61, 355), SMASS II (S.W. Bus, 1999, PhD Thesis, MIT), and the Bell et al. Atlas of the asteroid infrared spectra. The objects constituting the first sample were selected in order to give a good representation of the major asteroid taxonomic classes (at least three samples each class): C,S,D,A, and G. Both methods were able to distinguish all these groups confirming the validity of the adopted methods. The S class is hard to individuate as a consequence of the choice of I and J variables, which imply a lack of information on the absorption band at 1 micron. The other samples were obtained by random choice of the objects. Not all the major groups were well represented (less than three samples per groups), but the general trend of the asteroid taxonomy has been always obtained. We conclude that the quoted grouping of TNO/Centaurs is representative of some physico-chemical structure of the outer solar system small body population.

Gaussian process based intelligent sampling for measuring nano-structure surfaces

NASA Astrophysics Data System (ADS)

Sun, L. J.; Ren, M. J.; Yin, Y. H.

2016-09-01

Nanotechnology is the science and engineering that manipulate matters at nano scale, which can be used to create many new materials and devices with a vast range of applications. As the nanotech product increasingly enters the commercial marketplace, nanometrology becomes a stringent and enabling technology for the manipulation and the quality control of the nanotechnology. However, many measuring instruments, for instance scanning probe microscopy, are limited to relatively small area of hundreds of micrometers with very low efficiency. Therefore some intelligent sampling strategies should be required to improve the scanning efficiency for measuring large area. This paper presents a Gaussian process based intelligent sampling method to address this problem. The method makes use of Gaussian process based Bayesian regression as a mathematical foundation to represent the surface geometry, and the posterior estimation of Gaussian process is computed by combining the prior probability distribution with the maximum likelihood function. Then each sampling point is adaptively selected by determining the position which is the most likely outside of the required tolerance zone among the candidates and then inserted to update the model iteratively. Both simulationson the nominal surface and manufactured surface have been conducted on nano-structure surfaces to verify the validity of the proposed method. The results imply that the proposed method significantly improves the measurement efficiency in measuring large area structured surfaces.

ISO observations of obscured Asymptotic Giant Branch stars in the Large Magellanic Cloud

NASA Astrophysics Data System (ADS)

Trams, N. R.; van Loon, J. Th.; Waters, L. B. F. M.; Zijlstra, A. A.; Loup, C.; Whitelock, P. A.; Groenewegen, M. A. T.; Blommaert, J. A. D. L.; Siebenmorgen, R.; Heske, A.; Feast, M. W.

1999-06-01

We present ISO photometric and spectroscopic observations of a sample of 57 bright Asymptotic Giant Branch stars and red supergiants in the Large Magellanic Cloud, selected on the basis of IRAS colours indicative of high mass-loss rates. PHOT-P and PHOT-C photometry at 12, 25 and 60 mu m and CAM photometry at 12 mu m are used in combination with quasi-simultaneous ground-based near-IR photometry to construct colour-colour diagrams for all stars in our sample. PHOT-S and CAM-CVF spectra in the 3 to 14 mu m region are presented for 23 stars. From the colour-colour diagrams and the spectra, we establish the chemical types of the dust around 49 stars in this sample. Many stars have carbon-rich dust. The most luminous carbon star in the Magellanic Clouds has also a (minor) oxygen-rich component. OH/IR stars have silicate absorption with emission wings. The unique dataset presented here allows a detailed study of a representative sample of thermal-pulsing AGB stars with well-determined luminosities. This paper is based on observations with the Infrared Space Observatory (ISO). ISO is an ESA project with instruments funded by ESA member states (especially the PI countries: France, Germany, The Netherlands and the United Kingdom) and with the participation of ISAS and NASA.

Application of a Multivariant, Caucasian-Specific, Genotyped Donor Panel for Performance Validation of MDmulticard®, ID-System®, and Scangel® RhD/ABO Serotyping

PubMed Central

Gassner, Christoph; Rainer, Esther; Pircher, Elfriede; Markut, Lydia; Körmöczi, Günther F.; Jungbauer, Christof; Wessin, Dietmar; Klinghofer, Roswitha; Schennach, Harald; Schwind, Peter; Schönitzer, Diether

2009-01-01

Summary Background Validations of routinely used serological typing methods require intense performance evaluations typically including large numbers of samples before routine application. However, such evaluations could be improved considering information about the frequency of standard blood groups and their variants. Methods Using RHD and ABO population genetic data, a Caucasian-specific donor panel was compiled for a performance comparison of the three RhD and ABO serological typing methods MDmulticard (Medion Diagnostics), ID-System (DiaMed) and ScanGel (Bio-Rad). The final test panel included standard and variant RHD and ABO genotypes, e.g. RhD categories, partial and weak RhDs, RhD DELs, and ABO samples, mainly to interpret weak serological reactivity for blood group A specificity. All samples were from individuals recorded in our local DNA blood group typing database. Results For ‘standard’ blood groups, results of performance were clearly interpretable for all three serological methods compared. However, when focusing on specific variant phenotypes, pronounced differences in reaction strengths and specificities were observed between them. Conclusions A genetically and ethnically predefined donor test panel consisting of 93 individual samples only, delivered highly significant results for serological performance comparisons. Such small panels offer impressive representative powers, higher as such based on statistical chances and large numbers only. PMID:21113264

CDF Top Physics

DOE R&D Accomplishments Database

Tartarelli, G. F.; CDF Collaboration

1996-05-01

The authors present the latest results about top physics obtained by the CDF experiment at the Fermilab Tevatron collider. The data sample used for these analysis (about 110 pb{sup{minus}1}) represents almost the entire statistics collected by CDF during four years (1992--95) of data taking. This large data size has allowed detailed studies of top production and decay properties. The results discussed here include the determination of the top quark mass, the measurement of the production cross section, the study of the kinematics of the top events and a look at top decays.

Collision rates and impact velocities in the Main Asteroid Belt

NASA Technical Reports Server (NTRS)

Farinella, Paolo; Davis, Donald R.

1992-01-01

Wetherill's (1967) algorithm is presently used to compute the mutual collision probabilities and impact velocities of a set of 682 asteroids with large-than-50-km radius representative of a bias-free sample of asteroid orbits. While collision probabilities are nearly independent of eccentricities, a significant decrease is associated with larger inclinations. Collisional velocities grow steeply with orbital eccentricity and inclination, but with curiously small variation across the asteroid belt. Family asteroids are noted to undergo collisions with other family members 2-3 times more often than with nonmembers.

Sources of work motivation of business leaders in the USA and South Africa: a cross-cultural comparison using the Motivational Sources Inventory.

PubMed

Barbuto, John E; Gifford, Gregory T

2007-10-01

Motivational differences in response to the Motivation Sources Inventory were tested between U.S. (n = 138) and South-African (n = 114) work samples. Analysis indicated that American managers scored significantly higher on intrinsic process (fun), while South-African managers scored significantly higher on self-concept external and goal internalization when measured using ratio analysis. Replication and extension with large groups representative of populations of interest in conjunction with Hofstede's cultural dimensions could allow generalization.

Public Perspectives on Informed Consent for Biobanking

PubMed Central

Scott, Joan; Kaufman, David; Geller, Gail; LeRoy, Lisa; Hudson, Kathy

2009-01-01

The National Institutes of Health and other federal health agencies are considering establishing a national biobank to study the roles of genes and environment in health. We assessed the public's attitudes toward the proposed biobank, including preferences for providing informed consent. Sixteen focus groups were conducted, and themes arising from the focus groups were tested in a large, representative survey (n = 4659) of the general population. Our research demonstrates that when considering participating in a genomic biobank, individuals want ongoing choices and control over access to their samples and information. PMID:19833988

Arsenic occurrence in drinking water supply systems in ten municipalities in Vojvodina Region, Serbia.

PubMed

Jovanovic, Dragana; Jakovljević, Branko; Rašić-Milutinović, Zorica; Paunović, Katarina; Peković, Gordana; Knezević, Tanja

2011-02-01

Vojvodina, a northern region of Serbia, belongs to the Pannonian Basin, whose aquifers contain high concentrations of arsenic. This study represents arsenic levels in drinking water in ten municipalities in Serbia. Around 63% of all water samples exceeded Serbian and European standards for arsenic in drinking water. Large variations in arsenic were observed among supply systems. Arsenic concentrations in public water supply systems in Vojvodina were much higher than in other countries in the Pannonian Basin. Copyright © 2010 Elsevier Inc. All rights reserved.

Geochemistry of rock units at the potential repository level, Yucca Mountain, Nevada

USGS Publications Warehouse

Peterman, Z.E.; Cloke, P.L.

2002-01-01

The compositional variability of the phenocryst-poor member of the 12.8 Ma Topopah Spring Tuff at the potential repository level was assessed by duplicate analysis of 20 core samples from the cross drift at Yucca Mountain, Nevada. Previous analyses of outcrop and core samples of the Topopah Spring Tuff showed that the phenocryst-poor rhyolite, which includes both lithophysal and nonlithophysal zones, is relatively uniform in composition. Analyses of rock samples from the cross drift, the first from the actual potential repository block, also indicate the chemical homogeneity of this unit excluding localized deposits of vapor-phase minerals and low-temperature calcite and opal in fractures, cavities, and faults. The possible influence of vapor-phase minerals and calcite and opal coatings on rock composition at a scale sufficiently large to incorporate these heterogeneously distributed deposits was evaluated and is considered to be relatively minor. Therefore, the composition of the phenocryst-poor member of the Topopah Spring Tuff is considered to be adequately represented by the analyses of samples from the cross drift. The mean composition as represented by the 10 most abundant oxides in wt. % or g/100 g is: SiO2, 76.29; Al2O3, 12.55; FeO, 0.14; Fe2O3, 0.97; MgO, 0.13; CaO, 0.50; Na2O, 3.52; K2O, 4.83; TiO2, 0.11; and MnO, 0.07. ?? 2002 Published by Elsevier Science Ltd.

Molecular and antigenic characterization of bovine Coronavirus circulating in Argentinean cattle during 1994-2010.

PubMed

Bok, M; Miño, S; Rodriguez, D; Badaracco, A; Nuñes, I; Souza, S P; Bilbao, G; Louge Uriarte, E; Galarza, R; Vega, C; Odeon, A; Saif, L J; Parreño, V

2015-12-31

Bovine coronavirus (BCoV) is an important viral pathogen associated with neonatal calf diarrhea. Our aim was to investigate the incidence of BCoV in diarrhea outbreaks in beef and dairy herds from Argentina during 1994-2010. A total of 5.365 fecal samples from diarrheic calves were screened for BCoV diagnosis by ELISA. The virus was detected in 1.71% (92/5365) of the samples corresponding to 5.95% (63/1058) of the diarrhea cases in 239 beef and 324 dairy farms. The detection rate of BCoV was significantly higher in dairy than in beef herds: 12.13% (29/239) vs. 4.32% (14/324) respectively. Phylogenetic analysis of the hypervariable S1 region of seven representative samples (from different husbandry systems, farm locations and years of sampling) indicated that BCoV strains circulating in Argentinean beef and dairy herds formed a cluster distinct from other geographical regions. Interestingly, Argentinean strains are distantly related (at both the nucleotide and amino acid levels) with the Mebus historic reference BCoV strain included in the vaccines currently available in Argentina. However, Mebus-induced antibodies were capable of neutralizing the BCoV Arg95, a field strain adapted to grow in vitro, and vice versa, indicating that both strains belong to the same CoV serotype reported in cattle. This work represents the first large survey describing BCoV circulation in Argentinean cattle. Copyright © 2015. Published by Elsevier B.V.