29 CFR 1607.7 - Use of other validity studies.

Code of Federal Regulations, 2013 CFR

2013-07-01

... EMPLOYEE SELECTION PROCEDURES (1978) General Principles § 1607.7 Use of other validity studies. A. Validity studies not conducted by the user. Users may, under certain circumstances, support the use of selection... described in test manuals. While publishers of selection procedures have a professional obligation to...

Fluctuating selection across years and phenotypic variation in food-deceptive orchids.

PubMed

Scopece, Giovanni; Juillet, Nicolas; Lexer, Christian; Cozzolino, Salvatore

2017-01-01

Nectarless flowers that deceive pollinators offer an opportunity to study asymmetric plant-insect interactions. Orchids are a widely used model for studying these interactions because they encompass several thousand species adopting deceptive pollination systems. High levels of intra-specific phenotypic variation have been reported in deceptive orchids, suggesting a reduced consistency of pollinator-mediated selection on their floral traits. Nevertheless, several studies report on widespread directional selection mediated by pollinators even in these deceptive orchids. In this study we test the hypothesis that the observed selection can fluctuate across years in strength and direction thus likely contributing to the phenotypic variability of this orchid group. We performed a three-year study estimating selection differentials and selection gradients for nine phenotypic traits involved in insect attraction in two Mediterranean orchid species, namely Orchis mascula and O. pauciflora , both relying on a well-described food-deceptive pollination strategy. We found weak directional selection and marginally significant selection gradients in the two investigated species with significant intra-specific differences in selection differentials across years. Our data do not link this variation with a specific environmental cause, but our results suggest that pollinator-mediated selection in food-deceptive orchids can change in strength and in direction over time. In perennial plants, such as orchids, different selection differentials in the same populations in different flowering seasons can contribute to the maintenance of phenotypic variation often reported in deceptive orchids.

You're Hired! A Study Investigating Selection Practices for High School Teachers and the High School Principals' Role in Decision-Making

ERIC Educational Resources Information Center

Mulieri, Vincent K.

2010-01-01

The purpose of this study was to investigate teacher selection practices in public high schools on Long Island, New York. More specifically, this study sought to identify criteria used to guide teacher selection, how the criteria are developed and used within the process, and the role of the principal in teacher selection. This research was…

29 CFR 1607.5 - General standards for validity studies.

Code of Federal Regulations, 2014 CFR

2014-07-01

... experience on the job. J. Interim use of selection procedures. Users may continue the use of a selection... studies. A. Acceptable types of validity studies. For the purposes of satisfying these guidelines, users... which has an adverse impact and which selection procedure has an adverse impact, each user should...

29 CFR 1607.5 - General standards for validity studies.

Code of Federal Regulations, 2013 CFR

2013-07-01

... experience on the job. J. Interim use of selection procedures. Users may continue the use of a selection... studies. A. Acceptable types of validity studies. For the purposes of satisfying these guidelines, users... which has an adverse impact and which selection procedure has an adverse impact, each user should...

29 CFR 1607.5 - General standards for validity studies.

Code of Federal Regulations, 2012 CFR

2012-07-01

... experience on the job. J. Interim use of selection procedures. Users may continue the use of a selection... studies. A. Acceptable types of validity studies. For the purposes of satisfying these guidelines, users... which has an adverse impact and which selection procedure has an adverse impact, each user should...

76 FR 58018 - Draft Guidance for Industry on Self-Selection Studies for Nonprescription Drug Products...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-19

...] Draft Guidance for Industry on Self-Selection Studies for Nonprescription Drug Products; Availability...) is announcing the availability of a draft guidance for industry entitled ``Self-Selection Studies for Nonprescription Drug Products.'' The draft guidance is intended to provide recommendations to industry on the...

A Study of the Reliability, Validity, and Usefulness of Identified Pre-Teaching Predictors.

ERIC Educational Resources Information Center

Gress, James R.

This study investigates selectivity in teacher education. Using perspectives afforded by institutional admissions practices, teacher effectiveness research, and selected public school influences, the study explored both current policies and procedures in the selection of preservice students and the usefulness of a number of biographical,…

Advanced Platform Systems Technology study. Volume 2: Trade study and technology selection

NASA Technical Reports Server (NTRS)

1983-01-01

Three primary tasks were identified which include task 1-trade studies, task 2-trade study comparison and technology selection, and task 3-technology definition. Task 1 general objectives were to identify candidate technology trade areas, determine which areas have the highest potential payoff, define specific trades within the high payoff areas, and perform the trade studies. In order to satisfy these objectives, a structured, organized approach was employed. Candidate technology areas and specific trades were screened using consistent selection criteria and considering possible interrelationships. A data base comprising both manned and unmanned space platform documentation was used as a source of system and subsystem requirements. When requirements were not stated in the data base documentation, assumptions were made and recorded where necessary to characterize a particular spacecraft system. The requirements and assumptions were used together with the selection criteria to establish technology advancement goals and select trade studies. While both manned and unmanned platform data were used, the study was focused on the concept of an early manned space station.

A tool for selecting SNPs for association studies based on observed linkage disequilibrium patterns.

PubMed

De La Vega, Francisco M; Isaac, Hadar I; Scafe, Charles R

2006-01-01

The design of genetic association studies using single-nucleotide polymorphisms (SNPs) requires the selection of subsets of the variants providing high statistical power at a reasonable cost. SNPs must be selected to maximize the probability that a causative mutation is in linkage disequilibrium (LD) with at least one marker genotyped in the study. The HapMap project performed a genome-wide survey of genetic variation with about a million SNPs typed in four populations, providing a rich resource to inform the design of association studies. A number of strategies have been proposed for the selection of SNPs based on observed LD, including construction of metric LD maps and the selection of haplotype tagging SNPs. Power calculations are important at the study design stage to ensure successful results. Integrating these methods and annotations can be challenging: the algorithms required to implement these methods are complex to deploy, and all the necessary data and annotations are deposited in disparate databases. Here, we present the SNPbrowser Software, a freely available tool to assist in the LD-based selection of markers for association studies. This stand-alone application provides fast query capabilities and swift visualization of SNPs, gene annotations, power, haplotype blocks, and LD map coordinates. Wizards implement several common SNP selection workflows including the selection of optimal subsets of SNPs (e.g. tagging SNPs). Selected SNPs are screened for their conversion potential to either TaqMan SNP Genotyping Assays or the SNPlex Genotyping System, two commercially available genotyping platforms, expediting the set-up of genetic studies with an increased probability of success.

Sexual selection on morphological and physiological traits and fluctuating asymmetry in the black scavenger fly Sepsis cynipsea.

PubMed

Blanckenhorn, W U; Kraushaar, U R S; Teuschl, Y; Reim, C

2004-05-01

Previous univariate studies of the fly Sepsis cynipsea (Diptera: Sepsidae) have demonstrated spatiotemporally variable and consequently overall weak sexual selection favouring large male size, which is nevertheless stronger on average than fecundity selection favouring larger females. To identify specific target(s) of selection on body size and additional traits possibly affecting mating success, two multivariate field studies of sexual selection were conducted. In one study using seasonal replicates from three populations, we assessed 15 morphological traits. No clear targets of sexual selection on male size could be detected, perhaps because spatiotemporal variation in selection was again strong. In particular, there was no (current) selection on male abdomen length or fore coxa length, the only traits for which S. cynipsea males are not smaller than females. Interestingly, copulating males had a consistently shorter fore femur base, a secondary sexual trait, and a wider clasper (hypopygium) gap, an external genital trait. In a second study using daily and seasonal replicates from one population, we included physiological measures of energy reserves (lipids, glucose, glycogen), in addition to hind tibia length and fluctuating asymmetry (FA) of all pairs of legs. This study again confirmed the mating advantage of large males, and additionally suggests independent positive influences of lipids (the long-term energy stores), with effects of glucose and glycogen (the short-term energy stores) tending to be negative. FA of paired traits was not associated with male mating success. Our study suggests that inclusion of physiological measures and genital traits in phenomenological studies of selection, which is rare, would be fruitful in other species.

Improving site selection in clinical studies: a standardised, objective, multistep method and first experience results.

PubMed

Hurtado-Chong, Anahí; Joeris, Alexander; Hess, Denise; Blauth, Michael

2017-07-12

A considerable number of clinical studies experience delays, which result in increased duration and costs. In multicentre studies, patient recruitment is among the leading causes of delays. Poor site selection can result in low recruitment and bad data quality. Site selection is therefore crucial for study quality and completion, but currently no specific guidelines are available. Selection of sites adequate to participate in a prospective multicentre cohort study was performed through an open call using a newly developed objective multistep approach. The method is based on use of a network, definition of objective criteria and a systematic screening process. Out of 266 interested sites, 24 were shortlisted and finally 12 sites were selected to participate in the study. The steps in the process included an open call through a network, use of selection questionnaires tailored to the study, evaluation of responses using objective criteria and scripted telephone interviews. At each step, the number of candidate sites was quickly reduced leaving only the most promising candidates. Recruitment and quality of data went according to expectations in spite of the contracting problems faced with some sites. The results of our first experience with a standardised and objective method of site selection are encouraging. The site selection method described here can serve as a guideline for other researchers performing multicentre studies. ClinicalTrials.gov: NCT02297581. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

The impact of selection bias on vaccine effectiveness estimates from test-negative studies.

PubMed

Jackson, Michael L; Phillips, C Hallie; Benoit, Joyce; Kiniry, Erika; Madziwa, Lawrence; Nelson, Jennifer C; Jackson, Lisa A

2018-01-29

Estimates of vaccine effectiveness (VE) from test-negative studies may be subject to selection bias. In the context of influenza VE, we used simulations to identify situations in which meaningful selection bias can occur. We also analyzed observational study data for evidence of selection bias. For the simulation study, we defined a hypothetical population whose members are at risk for acute respiratory illness (ARI) due to influenza and other pathogens. An unmeasured "healthcare seeking proclivity" affects both probability of vaccination and probability of seeking care for an ARI. We varied the direction and magnitude of these effects and identified situations where meaningful bias occurred. For the observational study, we reanalyzed data from the United States Influenza VE Network, an ongoing test-negative study. We compared "bias-naïve" VE estimates to bias-adjusted estimates, which used data from the source populations to correct for sampling bias. In the simulation study, an unmeasured care-seeking proclivity could create selection bias if persons with influenza ARI were more (or less) likely to seek care than persons with non-influenza ARI. However, selection bias was only meaningful when rates of care seeking between influenza ARI and non-influenza ARI were very different. In the observational study, the bias-naïve VE estimate of 55% (95% CI, 47--62%) was trivially different from the bias-adjusted VE estimate of 57% (95% CI, 49--63%). In combination, these studies suggest that while selection bias is possible in test-negative VE studies, this bias in unlikely to be meaningful under conditions likely to be encountered in practice. Researchers and public health officials can continue to rely on VE estimates from test-negative studies. Copyright © 2017 Elsevier Ltd. All rights reserved.

A History and Case Study at a Selected Tribal College

ERIC Educational Resources Information Center

Oltrogge, Micheal P.

2010-01-01

"A History and Case Study at a Selected Tribal College" focuses on a tribally chartered two-year institution of higher education. The selected Tribal College serves Native American and non-Native American populations on two separate and distinct reservations and one urban location. This study surveys the history to answer basic foundational and…

Sexual Selection and the differences between the sexes in Mandrills (Mandrillus sphinx).

PubMed

Setchell, Joanna M

2016-01-01

Sexual selection has become a major focus in evolutionary and behavioral ecology. It is also a popular research topic in primatology. I use studies of mandrills (Mandrillus sphinx), a classic example of extravagant armaments and ornaments in animals, to exemplify how a long-term, multidisciplinary approach that integrates field observations with laboratory methods can contribute to on-going theoretical debates in the field of sexual selection. I begin with a brief summary of the main concepts of sexual selection theory and the differences between the sexes. I then introduce mandrills and the study population and review mandrill life history, the ontogeny of sex differences, and maternal effects. Next, I focus on male-male competition and female choice, followed by the less well-studied questions of female-female competition and male choice. This review shows how different reproductive priorities lead to very different life histories and divergent adaptations in males and females. It demonstrates how broadening traditional perspectives on sexual selection beyond the ostentatious results of intense sexual selection on males leads to an understanding of more subtle and cryptic forms of competition and choice in both sexes and opens many productive avenues in the study of primate reproductive strategies. These include the potential for studies of postcopulatory selection, female intrasexual competition, and male choice. These studies of mandrills provide comparison and, I hope, inspiration for studies of both other polygynandrous species and species with mating systems less traditionally associated with sexual selection. © 2016 Wiley Periodicals, Inc.

Combining epidemiology and biomechanics in sports injury prevention research: a new approach for selecting suitable controls.

PubMed

Finch, Caroline F; Ullah, Shahid; McIntosh, Andrew S

2011-01-01

Several important methodological issues need to be considered when designing sports injury case-control studies. Major design goals for case-control studies include the accounting for prior injury risk exposure, and optimal definitions of both cases and suitable controls are needed to ensure this. This article reviews methodological aspects of published sports injury case-control studies, particularly with regard to the selection of controls. It argues for a new approach towards selecting controls for case-control studies that draws on an interface between epidemiological and biomechanical concepts. A review was conducted to identify sport injury case-control studies published in the peer-review literature during 1985-2008. Overall, 32 articles were identified, of which the majority related to upper or lower extremity injuries. Matching considerations were used for control selection in 16 studies. Specific mention of application of biomechanical principles in the selection of appropriate controls was absent from all studies, including those purporting to evaluate the benefits of personal protective equipment to protect against impact injury. This is a problem because it could lead to biased conclusions, as cases and controls are not fully comparable in terms of similar biomechanical impact profiles relating to the injury incident, such as site of the impact on the body. The strength of the conclusions drawn from case-control studies, and the extent to which results can be generalized, is directly influenced by the definition and recruitment of cases and appropriate controls. Future studies should consider the interface between epidemiological and biomechanical concepts when choosing appropriate controls to ensure that proper adjustment of prior exposure to injury risk is made. To provide necessary guidance for the optimal selection of controls in case-control studies of interventions to prevent sports-related impact injury, this review outlines a new case-control selection strategy that reflects the importance of biomechanical considerations, which ensures that controls are selected based on the presence of the same global injury mechanism as the cases. To summarize, the general biomechanical principles that should apply to the selection of controls in future case-control studies are as follows: (i) each control must have been exposed to the same global injury mechanism as the case, (e.g. head impact, fall onto outstretched arm); and (ii) intrinsic (individual) factors (e.g. age, sex, skill level) that might modify the person's response to the relevant biomechanical loads are adjusted when either selecting the controls or are in the analysis phase. The same considerations for control selection apply to other study designs such as matched cohort studies or case-crossover studies.

Contextual control over selective attention: evidence from a two-target method.

PubMed

MacLellan, Ellen; Shore, David I; Milliken, Bruce

2015-07-01

Selective attention is generally studied with conflict tasks, using response time as the dependent measure. Here, we study the impact of selective attention to a first target, T1, presented simultaneously with a distractor, on the accuracy of subsequent encoding of a second target item, T2. This procedure produces an "attentional blink" (AB) effect much like that reported in other studies, and allowed us to study the influence of context on cognitive control with a novel method. In particular, we examined whether preparation to attend selectively to T1 had an impact on the selective encoding of T1 that would translate to report of T2. Preparation to attend selectively was manipulated by varying whether difficult selective attention T1 trials were presented in the context of other difficult selective attention T1 trials. The results revealed strong context effects of this nature, with smaller AB effects when difficult selective attention T1 trials were embedded in a context with many, rather than few, other difficult selective attention T1 trials. Further, the results suggest that both the trial-to-trial local context and the block-wide global context modulate performance in this task.

Cancers Selected for Study - TCGA

Cancer.gov

The Cancer Genome Atlas researchers are mapping the genetic changes in 33 cancers. Find out which cancers have been selected for study, the criteria for selection and the scientific questions being asked about each cancer.

GENERALITY OF THE MATCHING LAW AS A DESCRIPTOR OF SHOT SELECTION IN BASKETBALL

PubMed Central

Alferink, Larry A; Critchfield, Thomas S; Hitt, Jennifer L; Higgins, William J

2009-01-01

Based on a small sample of highly successful teams, past studies suggested that shot selection (two- vs. three-point field goals) in basketball corresponds to predictions of the generalized matching law. We examined the generality of this finding by evaluating shot selection of college (Study 1) and professional (Study 3) players. The matching law accounted for the majority of variance in shot selection, with undermatching and a bias for taking three-point shots. Shot-selection matching varied systematically for players who (a) were members of successful versus unsuccessful teams, (b) competed at different levels of collegiate play, and (c) served as regulars versus substitutes (Study 2). These findings suggest that the matching law is a robust descriptor of basketball shot selection, although the mechanism that produces matching is unknown. PMID:20190921

Principal Selection: A National Study of Selection Criteria and Procedures

ERIC Educational Resources Information Center

Palmer, Brandon

2017-01-01

Despite empirical evidence correlating the role of the principal with student achievement, researchers have seldom scrutinized principal selection methods over the past 60 years. This mixed methods study investigated the processes by which school principals are selected. A national sample of top-level school district administrators was used to…

Principal Selection: A National Study of Selection Criteria and Procedures

ERIC Educational Resources Information Center

Palmer, Brandon

2016-01-01

Despite empirical evidence correlating the role of the principal with student achievement, researchers have seldom scrutinized principal selection methods over the past 60 years. This mixed methods study investigated the processes by which school principals are selected. A national sample of top-level school district administrators was used to…

Spatio-temporal Bayesian model selection for disease mapping

PubMed Central

Carroll, R; Lawson, AB; Faes, C; Kirby, RS; Aregay, M; Watjou, K

2016-01-01

Spatio-temporal analysis of small area health data often involves choosing a fixed set of predictors prior to the final model fit. In this paper, we propose a spatio-temporal approach of Bayesian model selection to implement model selection for certain areas of the study region as well as certain years in the study time line. Here, we examine the usefulness of this approach by way of a large-scale simulation study accompanied by a case study. Our results suggest that a special case of the model selection methods, a mixture model allowing a weight parameter to indicate if the appropriate linear predictor is spatial, spatio-temporal, or a mixture of the two, offers the best option to fitting these spatio-temporal models. In addition, the case study illustrates the effectiveness of this mixture model within the model selection setting by easily accommodating lifestyle, socio-economic, and physical environmental variables to select a predominantly spatio-temporal linear predictor. PMID:28070156

Evidence for the Selective Reporting of Analyses and Discrepancies in Clinical Trials: A Systematic Review of Cohort Studies of Clinical Trials

PubMed Central

Dwan, Kerry; Altman, Douglas G.; Clarke, Mike; Gamble, Carrol; Higgins, Julian P. T.; Sterne, Jonathan A. C.; Williamson, Paula R.; Kirkham, Jamie J.

2014-01-01

Background Most publications about selective reporting in clinical trials have focussed on outcomes. However, selective reporting of analyses for a given outcome may also affect the validity of findings. If analyses are selected on the basis of the results, reporting bias may occur. The aims of this study were to review and summarise the evidence from empirical cohort studies that assessed discrepant or selective reporting of analyses in randomised controlled trials (RCTs). Methods and Findings A systematic review was conducted and included cohort studies that assessed any aspect of the reporting of analyses of RCTs by comparing different trial documents, e.g., protocol compared to trial report, or different sections within a trial publication. The Cochrane Methodology Register, Medline (Ovid), PsycInfo (Ovid), and PubMed were searched on 5 February 2014. Two authors independently selected studies, performed data extraction, and assessed the methodological quality of the eligible studies. Twenty-two studies (containing 3,140 RCTs) published between 2000 and 2013 were included. Twenty-two studies reported on discrepancies between information given in different sources. Discrepancies were found in statistical analyses (eight studies), composite outcomes (one study), the handling of missing data (three studies), unadjusted versus adjusted analyses (three studies), handling of continuous data (three studies), and subgroup analyses (12 studies). Discrepancy rates varied, ranging from 7% (3/42) to 88% (7/8) in statistical analyses, 46% (36/79) to 82% (23/28) in adjusted versus unadjusted analyses, and 61% (11/18) to 100% (25/25) in subgroup analyses. This review is limited in that none of the included studies investigated the evidence for bias resulting from selective reporting of analyses. It was not possible to combine studies to provide overall summary estimates, and so the results of studies are discussed narratively. Conclusions Discrepancies in analyses between publications and other study documentation were common, but reasons for these discrepancies were not discussed in the trial reports. To ensure transparency, protocols and statistical analysis plans need to be published, and investigators should adhere to these or explain discrepancies. Please see later in the article for the Editors' Summary PMID:24959719

Transferability of optimally-selected climate models in the quantification of climate change impacts on hydrology

NASA Astrophysics Data System (ADS)

Chen, Jie; Brissette, François P.; Lucas-Picher, Philippe

2016-11-01

Given the ever increasing number of climate change simulations being carried out, it has become impractical to use all of them to cover the uncertainty of climate change impacts. Various methods have been proposed to optimally select subsets of a large ensemble of climate simulations for impact studies. However, the behaviour of optimally-selected subsets of climate simulations for climate change impacts is unknown, since the transfer process from climate projections to the impact study world is usually highly non-linear. Consequently, this study investigates the transferability of optimally-selected subsets of climate simulations in the case of hydrological impacts. Two different methods were used for the optimal selection of subsets of climate scenarios, and both were found to be capable of adequately representing the spread of selected climate model variables contained in the original large ensemble. However, in both cases, the optimal subsets had limited transferability to hydrological impacts. To capture a similar variability in the impact model world, many more simulations have to be used than those that are needed to simply cover variability from the climate model variables' perspective. Overall, both optimal subset selection methods were better than random selection when small subsets were selected from a large ensemble for impact studies. However, as the number of selected simulations increased, random selection often performed better than the two optimal methods. To ensure adequate uncertainty coverage, the results of this study imply that selecting as many climate change simulations as possible is the best avenue. Where this was not possible, the two optimal methods were found to perform adequately.

Generality of the Matching Law as a Descriptor of Shot Selection in Basketball

ERIC Educational Resources Information Center

Alferink, Larry A.; Critchfield, Thomas S.; Hitt, Jennifer L.; Higgins, William J.

2009-01-01

Based on a small sample of highly successful teams, past studies suggested that shot selection (two- vs. three-point field goals) in basketball corresponds to predictions of the generalized matching law. We examined the generality of this finding by evaluating shot selection of college (Study 1) and professional (Study 3) players. The matching law…

Perceived Indices of Truancy among Selected Adolescents in Oyo Town: Implications for Behavioural Change

ERIC Educational Resources Information Center

Adika, Lawrence Olagoke

2016-01-01

The study investigated perceived indices of truancy behaviour among selected adolescents in Oyo town. The descriptive survey study had 200 randomly selected adolescents from five secondary schools in Oyo town. A self-designed instrument tagged Adolescent Truancy Scale (ATS) was employed in collecting data for the study and the data was subjected…

Rethinking the assessment of risk of bias due to selective reporting: a cross-sectional study.

PubMed

Page, Matthew J; Higgins, Julian P T

2016-07-08

Selective reporting is included as a core domain of Cochrane's tool for assessing risk of bias in randomised trials. There has been no evaluation of review authors' use of this domain. We aimed to evaluate assessments of selective reporting in a cross-section of Cochrane reviews and to outline areas for improvement. We obtained data on selective reporting judgements for 8434 studies included in 586 Cochrane reviews published from issue 1-8, 2015. One author classified the reasons for judgements of high risk of selective reporting bias. We randomly selected 100 reviews with at least one trial rated at high risk of outcome non-reporting bias (non-/partial reporting of an outcome on the basis of its results). One author recorded whether the authors of these reviews incorporated the selective reporting assessment when interpreting results. Of the 8434 studies, 1055 (13 %) were rated at high risk of bias on the selective reporting domain. The most common reason was concern about outcome non-reporting bias. Few studies were rated at high risk because of concerns about bias in selection of the reported result (e.g. reporting of only a subset of measurements, analysis methods or subsets of the data that were pre-specified). Review authors often specified in the risk of bias tables the study outcomes that were not reported (84 % of studies) but less frequently specified the outcomes that were partially reported (61 % of studies). At least one study was rated at high risk of outcome non-reporting bias in 31 % of reviews. In the random sample of these reviews, only 30 % incorporated this information when interpreting results, by acknowledging that the synthesis of an outcome was missing data that were not/partially reported. Our audit of user practice in Cochrane reviews suggests that the assessment of selective reporting in the current risk of bias tool does not work well. It is not always clear which outcomes were selectively reported or what the corresponding risk of bias is in the synthesis with missing outcome data. New tools that will make it easier for reviewers to convey this information are being developed.

Clinical Trial Registries Are of Minimal Use for Identifying Selective Outcome and Analysis Reporting

ERIC Educational Resources Information Center

Norris, Susan L.; Holmer, Haley K.; Fu, Rongwei; Ogden, Lauren A.; Viswanathan, Meera S.; Abou-Setta, Ahmed M.

2014-01-01

Objective: This study aimed to examine selective outcome reporting (SOR) and selective analysis reporting (SAR) in randomized controlled trials (RCTs) and to explore the usefulness of trial registries for identifying SOR and SAR. Study Design and Setting: We selected one "index outcome" for each of three comparative effectiveness reviews…

A feasibility study of orbiter flight control experiments

NASA Technical Reports Server (NTRS)

Geissler, W. H.

1978-01-01

The results of a feasibility study of orbiter flight control experiments performed are summarized. Feasibility studies were performed on a group of 14 experiments selected from a candidate list of 35 submitted to the study contractor by the flight control community. Concepts and requirements were developed for the 14 selected experiments and they were ranked on a basis of technical value, feasibility, and cost. It was concluded that all the selected experiments can be considered as potential candidates for the Orbiter Experiment program, which is being formulated for the Orbiter Flight Tests and subsequent operational flights, regardless of the relative ranking established during the study. None of the selected experiments has significant safety implications and the cost of most was estimated to be less than $200K.

The Influence of Self-Esteem on the Mate Selection Process of African American Females: Implications for Counseling

ERIC Educational Resources Information Center

Gibson-Bilton, Joya

2009-01-01

The purpose of this study was twofold. First, this study examined the influence of African American females' level of self-esteem on the mate-selection process. Secondly, this study was concerned with the influence of the level of self-esteem of African American females on valuing the mate-selection characteristics of interpersonal skills,…

Production rates and costs of group selection harvests with a christy cable yarder

Treesearch

Chris B. LeDoux; John E. Baumgras; James Sherar; Tom Campbell

1991-01-01

Group selection harvest studies in Eastern hardwoods have shown that economic success of such harvests rests heavily on product market values, tree quality, and logging costs (Boucher and Hall 1989; Bell 1989). Other studies have attempted to define group selection harvests and where they can be used (Roach 1974). Additional studies have documented the reproduction of...

A regularized variable selection procedure in additive hazards model with stratified case-cohort design.

PubMed

Ni, Ai; Cai, Jianwen

2018-07-01

Case-cohort designs are commonly used in large epidemiological studies to reduce the cost associated with covariate measurement. In many such studies the number of covariates is very large. An efficient variable selection method is needed for case-cohort studies where the covariates are only observed in a subset of the sample. Current literature on this topic has been focused on the proportional hazards model. However, in many studies the additive hazards model is preferred over the proportional hazards model either because the proportional hazards assumption is violated or the additive hazards model provides more relevent information to the research question. Motivated by one such study, the Atherosclerosis Risk in Communities (ARIC) study, we investigate the properties of a regularized variable selection procedure in stratified case-cohort design under an additive hazards model with a diverging number of parameters. We establish the consistency and asymptotic normality of the penalized estimator and prove its oracle property. Simulation studies are conducted to assess the finite sample performance of the proposed method with a modified cross-validation tuning parameter selection methods. We apply the variable selection procedure to the ARIC study to demonstrate its practical use.

Selected field and analytical methods and analytical results in the Dutch Flats area, western Nebraska, 1995-99

USGS Publications Warehouse

Verstraeten, Ingrid M.; Steele, G.V.; Cannia, J.C.; Bohlke, J.K.; Kraemer, T.E.; Hitch, D.E.; Wilson, K.E.; Carnes, A.E.

2001-01-01

A study of the water resources of the Dutch Flats area in the western part of the North Platte Natural Resources District, western Nebraska, was conducted from 1995 through 1999 to describe the surface water and hydrogeology, the spatial distribution of selected water-quality constituents in surface and ground water, and the surface-water/ground-water interaction in selected areas. This report describes the selected field and analytical methods used in the study and selected analytical results from the study not previously published. Specifically, dissolved gases, age-dating data, and other isotopes collected as part of an intensive sampling effort in August and November 1998 and all uranium and uranium isotope data collected through the course of this study are included in the report.

Opposing selection and environmental variation modify optimal timing of breeding.

PubMed

Tarwater, Corey E; Beissinger, Steven R

2013-09-17

Studies of evolution in wild populations often find that the heritable phenotypic traits of individuals producing the most offspring do not increase proportionally in the population. This paradox may arise when phenotypic traits influence both fecundity and viability and when there is a tradeoff between these fitness components, leading to opposing selection. Such tradeoffs are the foundation of life history theory, but they are rarely investigated in selection studies. Timing of breeding is a classic example of a heritable trait under directional selection that does not result in an evolutionary response. Using a 22-y study of a tropical parrot, we show that opposing viability and fecundity selection on the timing of breeding is common and affects optimal breeding date, defined by maximization of fitness. After accounting for sampling error, the directions of viability (positive) and fecundity (negative) selection were consistent, but the magnitude of selection fluctuated among years. Environmental conditions (rainfall and breeding density) primarily and breeding experience secondarily modified selection, shifting optimal timing among individuals and years. In contrast to other studies, viability selection was as strong as fecundity selection, late-born juveniles had greater survival than early-born juveniles, and breeding later in the year increased fitness under opposing selection. Our findings provide support for life history tradeoffs influencing selection on phenotypic traits, highlight the need to unify selection and life history theory, and illustrate the importance of monitoring survival as well as reproduction for understanding phenological responses to climate change.

A Selective Review of Group Selection in High-Dimensional Models

PubMed Central

Huang, Jian; Breheny, Patrick; Ma, Shuangge

2013-01-01

Grouping structures arise naturally in many statistical modeling problems. Several methods have been proposed for variable selection that respect grouping structure in variables. Examples include the group LASSO and several concave group selection methods. In this article, we give a selective review of group selection concerning methodological developments, theoretical properties and computational algorithms. We pay particular attention to group selection methods involving concave penalties. We address both group selection and bi-level selection methods. We describe several applications of these methods in nonparametric additive models, semiparametric regression, seemingly unrelated regressions, genomic data analysis and genome wide association studies. We also highlight some issues that require further study. PMID:24174707

Changes in Food Selectivity in Children with Autism Spectrum Disorder

ERIC Educational Resources Information Center

Bandini, Linda G.; Curtin, Carol; Phillips, Sarah; Anderson, Sarah E.; Maslin, Melissa; Must, Aviva

2017-01-01

Food selectivity is a common problem in children with autism spectrum disorder (ASD) and has an adverse impact on nutrient adequacy and family mealtimes. Despite recent research in this area, few studies have addressed whether food selectivity present in children with ASD persists into adolescence. In this study, we assessed food selectivity in 18…

49 CFR 268.21 - Down-selection of one or more Maglev projects for further study and selection of one project for...

Code of Federal Regulations, 2014 CFR

2014-10-01

... further study and selection of one project for final design, engineering, and construction funding. 268.21... and selection of one project for final design, engineering, and construction funding. (a) Upon... analyses necessary prior to initiation of construction. Final design and engineering work will also be...

49 CFR 268.21 - Down-selection of one or more Maglev projects for further study and selection of one project for...

Code of Federal Regulations, 2010 CFR

2010-10-01

... further study and selection of one project for final design, engineering, and construction funding. 268.21... and selection of one project for final design, engineering, and construction funding. (a) Upon... analyses necessary prior to initiation of construction. Final design and engineering work will also be...

49 CFR 268.21 - Down-selection of one or more Maglev projects for further study and selection of one project for...

Code of Federal Regulations, 2011 CFR

2011-10-01

... further study and selection of one project for final design, engineering, and construction funding. 268.21... and selection of one project for final design, engineering, and construction funding. (a) Upon... analyses necessary prior to initiation of construction. Final design and engineering work will also be...

49 CFR 268.21 - Down-selection of one or more Maglev projects for further study and selection of one project for...

Code of Federal Regulations, 2012 CFR

2012-10-01

... further study and selection of one project for final design, engineering, and construction funding. 268.21... and selection of one project for final design, engineering, and construction funding. (a) Upon... analyses necessary prior to initiation of construction. Final design and engineering work will also be...

49 CFR 268.21 - Down-selection of one or more Maglev projects for further study and selection of one project for...

Code of Federal Regulations, 2013 CFR

2013-10-01

... further study and selection of one project for final design, engineering, and construction funding. 268.21... and selection of one project for final design, engineering, and construction funding. (a) Upon... analyses necessary prior to initiation of construction. Final design and engineering work will also be...

Head First into the Patron-Driven Acquisition Pool: A Comparison of Librarian Selections versus Patron Purchases

ERIC Educational Resources Information Center

Shen, Lisa; Cassidy, Erin Dorris; Elmore, Eric; Griffin, Glenda; Manolovitz, Tyler; Martinez, Michelle; Turney, Linda M.

2011-01-01

Although many recent studies have been conducted on the implementation and results of patron-driven acquisition (PDA) initiatives at academic libraries, very few have focused on whether, or how, patrons' selections vary from selection choices librarians would have made. This study compares titles selected by patrons during a PDA pilot program…

Estimating a test's accuracy using tailored meta-analysis-How setting-specific data may aid study selection.

PubMed

Willis, Brian H; Hyde, Christopher J

2014-05-01

To determine a plausible estimate for a test's performance in a specific setting using a new method for selecting studies. It is shown how routine data from practice may be used to define an "applicable region" for studies in receiver operating characteristic space. After qualitative appraisal, studies are selected based on the probability that their study accuracy estimates arose from parameters lying in this applicable region. Three methods for calculating these probabilities are developed and used to tailor the selection of studies for meta-analysis. The Pap test applied to the UK National Health Service (NHS) Cervical Screening Programme provides a case example. The meta-analysis for the Pap test included 68 studies, but at most 17 studies were considered applicable to the NHS. For conventional meta-analysis, the sensitivity and specificity (with 95% confidence intervals) were estimated to be 72.8% (65.8, 78.8) and 75.4% (68.1, 81.5) compared with 50.9% (35.8, 66.0) and 98.0% (95.4, 99.1) from tailored meta-analysis using a binomial method for selection. Thus, for a cervical intraepithelial neoplasia (CIN) 1 prevalence of 2.2%, the post-test probability for CIN 1 would increase from 6.2% to 36.6% between the two methods of meta-analysis. Tailored meta-analysis provides a method for augmenting study selection based on the study's applicability to a setting. As such, the summary estimate is more likely to be plausible for a setting and could improve diagnostic prediction in practice. Copyright © 2014 Elsevier Inc. All rights reserved.

Relationship between neural response and adaptation selectivity to form and color: an ERP study.

PubMed

Rentzeperis, Ilias; Nikolaev, Andrey R; Kiper, Daniel C; van Leeuwen, Cees

2012-01-01

Adaptation is widely used as a tool for studying selectivity to visual features. In these studies it is usually assumed that the loci of feature selective neural responses and adaptation coincide. We used an adaptation paradigm to investigate the relationship between response and adaptation selectivity in event-related potentials (ERPs). ERPs were evoked by the presentation of colored Glass patterns in a form discrimination task. Response selectivities to form and, to some extent, color of the patterns were reflected in the C1 and N1 ERP components. Adaptation selectivity to color was reflected in N1 and was followed by a late (300-500 ms after stimulus onset) effect of form adaptation. Thus for form, response and adaptation selectivity were manifested in non-overlapping intervals. These results indicate that adaptation and response selectivity can be associated with different processes. Therefore, inferring selectivity from an adaptation paradigm requires analysis of both adaptation and neural response data.

Selecting Candidates for Key Leadership Positions in Program Executive Offices Ground Combat Systems and Combat Service and Combat Service Support

DTIC Science & Technology

2016-10-14

the quantitative and qualitative data for this study . This study focuses on determining how well the current process for selecting candidates... Research Design This study is structured as a mixed methods survey, incorporating qualitative and quantitative questions. Mixed method was selected to...Management Command (LCMC) on the Detroit Arsenal in Warren, MI. At the time of the study , PEO GCS and PEO CS&CSS did not have a specific policy for

Study Habits and Academic Performance of Secondary School Students in Mathematic: A Case Study of Selected Secondary Schools in Uyo Local Education Council

ERIC Educational Resources Information Center

Sakirudeen, Abisola Oladeni; Sanni, Kudirat Bimbo

2017-01-01

The study examined study habits and academic performance of secondary school students in Mathematics. A case study of selected secondary schools in Uyo Local Education Council. The main purpose of the study was to investigate the relationship between study habits and academic performance of secondary school students in Mathematics. To carry out…

Selected Reference Books of 2000/2001.

ERIC Educational Resources Information Center

McIlvaine, Eileen

2002-01-01

Presents an annotated list of selected recent scholarly and general reference works under the subject categories of archives; literature; music; psychology; sociology; black studies; women's studies; history and area studies; and new editions and supplements. (LRW)

Textbook Development and Selection in Japan and the United States.

ERIC Educational Resources Information Center

Tani, Masaru; And Others

1993-01-01

Reports on a study trip by 13 U.S. social studies educators and publishers to Japan. Compares development, marketing, and selection of textbooks in the United States and Japan. Concludes that both nations should improve textbooks and textbook selection processes. (CFR)

Exploring Selective Exposure and Confirmation Bias as Processes Underlying Employee Work Happiness: An Intervention Study.

PubMed

Williams, Paige; Kern, Margaret L; Waters, Lea

2016-01-01

Employee psychological capital (PsyCap), perceptions of organizational virtue (OV), and work happiness have been shown to be associated within and over time. This study examines selective exposure and confirmation bias as potential processes underlying PsyCap, OV, and work happiness associations. As part of a quasi-experimental study design, school staff (N = 69) completed surveys at three time points. After the first assessment, some staff (n = 51) completed a positive psychology training intervention. Results of descriptive statistics, correlation, and regression analyses on the intervention group provide some support for selective exposure and confirmation bias as explanatory mechanisms. In focusing on the processes through which employee attitudes may influence work happiness this study advances theoretical understanding, specifically of selective exposure and confirmation bias in a field study context.

Selection Process of School Principals in Turkey and Some Other Countries: A Comparative Study

ERIC Educational Resources Information Center

Akbasli, Sait; Sahin, Mehmet; Gül, Burak

2017-01-01

The purpose of this study is to analyze the process of school principal selection and appointment in Turkey and some other developed countries in a comparative way. The specific purpose is to make suggestions in order to improve the school principal selection process in Turkey by comparatively analyzing school principal selection process in Turkey…

Pre-Service Teachers' Comments toward Official Teacher Selection System (Civil Servant Selection Examination, KPSS) in Turkey: A Qualitative Analysis

ERIC Educational Resources Information Center

Ugulu, Ilker; Yorek, Nurettin

2015-01-01

The purpose of this research is to investigate the opinions of the pre-service teachers toward teacher selection system and civil servant selection exam (KPSS). In this study, qualitative re-search methods and semi-structured interviews were used and researcher-made questionnaires containing open-ended questions were administered. The study group…

The role of Parenting and Goal Selection in Positive Youth Development: A Person-Centered Approach

ERIC Educational Resources Information Center

Napolitano, Christopher M.; Bowers, Edmond P.; Gestsdottir, Steinunn; Depping, Miriam; von Eye, Alexander; Chase, Paul; Lerner, Jacqueline V.

2011-01-01

Using a person-centered approach, we examined the relations between goal selection, various indicators of parenting, and positive development among 510 Grades 9 to 11 participants (68% female) in the 4-H Study of Positive Youth Development (PYD), a longitudinal study involving U.S. adolescents. Goal selection was operationalized by the "Selection"…

Pretest Measures of the Study Outcome and the Elimination of Selection Bias: Evidence from Three Within Study Comparisons.

PubMed

Hallberg, Kelly; Cook, Thomas D; Steiner, Peter M; Clark, M H

2018-04-01

This paper examines how pretest measures of a study outcome reduce selection bias in observational studies in education. The theoretical rationale for privileging pretests in bias control is that they are often highly correlated with the outcome, and in many contexts, they are also highly correlated with the selection process. To examine the pretest's role in bias reduction, we use the data from two within study comparisons and an especially strong quasi-experiment, each with an educational intervention that seeks to improve achievement. In each study, the pretest measures are consistently highly correlated with post-intervention measures of themselves, but the studies vary the correlation between the pretest and the process of selection into treatment. Across the three datasets with two outcomes each, there are three cases where this correlation is low and three where it is high. A single wave of pretest always reduces bias across the six instances examined, and it eliminates bias in three of them. Adding a second pretest wave eliminates bias in two more instances. However, the pattern of bias elimination does not follow the predicted pattern-that more bias reduction ensues as a function of how highly the pretest is correlated with selection. The findings show that bias is more complexly related to the pretest's correlation with selection than we hypothesized, and we seek to explain why.

Feasibility of Integration of Selected Aspects of (CBA) Chemistry, (CHEMS) Chemistry and (PSSC) Physics into a Two Year Physical Science Sequence.

ERIC Educational Resources Information Center

Fiasca, Michael Aldo

Compared, for selected outcomes, were integrated chemistry-physics courses with chemistry and physics courses taught separately. Three classes studying integrated Physical Science Study Committee (PSSC)-Chemical Bond Approach (CBA), and three classes studying integrated Physical Science Study Committee-Chemical Education Materials Study (CHEMS)…

The Relation between Self-Selected Study Processes and Test Performance.

ERIC Educational Resources Information Center

Nist, Sherrie L.; And Others

1991-01-01

A correlational study examined the relationship between test performance and four study processes (encoding, word meaning, organizing, and executive control). Results with 123 college freshmen trained to use study strategies suggest that executive control is related to test performance and that trained subjects select a variety of strategies…

High hunting pressure selects for earlier birth date: Wild boar as a case study

USGS Publications Warehouse

Gamelon, M.; Besnard, A.; Gaillard, J.-M.; Servanty, S.; Baubet, E.; Brandt, S.; Gimenez, O.

2011-01-01

Exploitation by humans affects the size and structure of populations. This has evolutionary and demographic consequences that have typically being studied independent of one another. We here applied a framework recently developed applying quantitative tools from population ecology and selection gradient analysis to quantify the selection on a quantitative trait-birth date-through its association with multiple fitness components. From the long-term monitoring (22 years) of a wild boar (Sus scrofa scrofa) population subject to markedly increasing hunting pressure, we found that birth dates have advanced by up to 12 days throughout the study period. During the period of low hunting pressure, there was no detectable selection. However, during the period of high hunting pressure, the selection gradient linking breeding probability in the first year of life to birth date was negative, supporting current life-history theory predicting selection for early births to reproduce within the first year of life with increasing adult mortality. ?? 2011 The Author(s). Evolution?? 2011 The Society for the Study of Evolution..

Multilocus approaches for the measurement of selection on correlated genetic loci.

PubMed

Gompert, Zachariah; Egan, Scott P; Barrett, Rowan D H; Feder, Jeffrey L; Nosil, Patrik

2017-01-01

The study of ecological speciation is inherently linked to the study of selection. Methods for estimating phenotypic selection within a generation based on associations between trait values and fitness (e.g. survival) of individuals are established. These methods attempt to disentangle selection acting directly on a trait from indirect selection caused by correlations with other traits via multivariate statistical approaches (i.e. inference of selection gradients). The estimation of selection on genotypic or genomic variation could also benefit from disentangling direct and indirect selection on genetic loci. However, achieving this goal is difficult with genomic data because the number of potentially correlated genetic loci (p) is very large relative to the number of individuals sampled (n). In other words, the number of model parameters exceeds the number of observations (p ≫ n). We present simulations examining the utility of whole-genome regression approaches (i.e. Bayesian sparse linear mixed models) for quantifying direct selection in cases where p ≫ n. Such models have been used for genome-wide association mapping and are common in artificial breeding. Our results show they hold promise for studies of natural selection in the wild and thus of ecological speciation. But we also demonstrate important limitations to the approach and discuss study designs required for more robust inferences. © 2016 John Wiley & Sons Ltd.

Does self-selection affect samples' representativeness in online surveys? An investigation in online video game research.

PubMed

Khazaal, Yasser; van Singer, Mathias; Chatton, Anne; Achab, Sophia; Zullino, Daniele; Rothen, Stephane; Khan, Riaz; Billieux, Joel; Thorens, Gabriel

2014-07-07

The number of medical studies performed through online surveys has increased dramatically in recent years. Despite their numerous advantages (eg, sample size, facilitated access to individuals presenting stigmatizing issues), selection bias may exist in online surveys. However, evidence on the representativeness of self-selected samples in online studies is patchy. Our objective was to explore the representativeness of a self-selected sample of online gamers using online players' virtual characters (avatars). All avatars belonged to individuals playing World of Warcraft (WoW), currently the most widely used online game. Avatars' characteristics were defined using various games' scores, reported on the WoW's official website, and two self-selected samples from previous studies were compared with a randomly selected sample of avatars. We used scores linked to 1240 avatars (762 from the self-selected samples and 478 from the random sample). The two self-selected samples of avatars had higher scores on most of the assessed variables (except for guild membership and exploration). Furthermore, some guilds were overrepresented in the self-selected samples. Our results suggest that more proficient players or players more involved in the game may be more likely to participate in online surveys. Caution is needed in the interpretation of studies based on online surveys that used a self-selection recruitment procedure. Epidemiological evidence on the reduced representativeness of sample of online surveys is warranted.

Patterns of analgesic and anti-inflammatory medicine use by Australian veterans.

PubMed

Pearson, S-A; Ringland, C; Kelman, C; Mant, A; Lowinger, J; Stark, H; Nichol, G; Day, R; Henry, D

2007-12-01

We examined analgesic and anti-inflammatory medicine use by Australian veterans before and after the introduction of selective Cox-2 inhibitors. We studied cohorts of Gold Card-holding veterans using prescription data held by the Department of Veterans' Affairs for the period 1 July 1998 to 30 June 2004. Outcomes were volume dispensed, average daily quantity and cumulative incidence of use of paracetamol-containing and aspirin-containing medicines, non-selective and Cox-2-selective non-steroidal anti-inflammatory drugs (NSAIDs), tramadol and dextropropoxyphene. Overall, we found high levels of use of analgesic and anti-inflammatory medicines, which increased by 43% over the study period. Use of paracetamol-containing medicines was overtaken by NSAIDs in 1999/2000, corresponding to the introduction of the Cox-2-selective agents. Between 12 and 17% of Cox-2-selective medicine recipients were supplied amounts indicative of continuous use in relatively high doses and 51% of veterans received at least one relatively Cox-2-selective medicine (celecoxib, rofecoxib, meloxicam, diclofenac) by the end of the study period. Dextropropoxyphene use declined during the study and tramadol use increased 10-fold. This study shows very high levels of Cox-2 inhibitor use during the 6-year period. Cox-2-selective agents were more likely to be taken continuously and at higher doses than non-selective NSAIDs. This is relevant in view of the cardiovascular toxicity of this group of medicines. The study shows the value of using unit record dispensing data to assess drug use patterns. Linking dispensing records to hospital separation and mortality data will further enhance our ability to monitor drug safety.

Selected Factors Related to Selective Service Rejection and Rejection Rate in Delaware (1967): A Study of the Characteristics of Young Men Failing to Meet Mental Qualifications for Military Service.

ERIC Educational Resources Information Center

Price, Jay R.

This study sought information about selective service rejection in Delaware, specifically rejectee characteristics, reasons for rejection, and the high rejection rate in Delaware. The basic design was a modified case study method in which a sample of individual records were examined. Differences between this sample and national samples were tested…

Final Report of the Montana Public School Students' Out-of-School Time Study. Research Report.

ERIC Educational Resources Information Center

Astroth, Kirk A.; Haynes, George W.

This paper reports on a study that explored the results of a statewide survey conducted in 21 randomly selected counties in Montana during fall 2000. Within each county, no more than 2 school districts were selected for further study, and within each school district, students in the 5th, 7th, and 9th grades were selected to participate in the…

IT vendor selection model by using structural equation model & analytical hierarchy process

NASA Astrophysics Data System (ADS)

Maitra, Sarit; Dominic, P. D. D.

2012-11-01

Selecting and evaluating the right vendors is imperative for an organization's global marketplace competitiveness. Improper selection and evaluation of potential vendors can dwarf an organization's supply chain performance. Numerous studies have demonstrated that firms consider multiple criteria when selecting key vendors. This research intends to develop a new hybrid model for vendor selection process with better decision making. The new proposed model provides a suitable tool for assisting decision makers and managers to make the right decisions and select the most suitable vendor. This paper proposes a Hybrid model based on Structural Equation Model (SEM) and Analytical Hierarchy Process (AHP) for long-term strategic vendor selection problems. The five steps framework of the model has been designed after the thorough literature study. The proposed hybrid model will be applied using a real life case study to assess its effectiveness. In addition, What-if analysis technique will be used for model validation purpose.

Effect of individual thinking styles on item selection during study time allocation.

PubMed

Jia, Xiaoyu; Li, Weijian; Cao, Liren; Li, Ping; Shi, Meiling; Wang, Jingjing; Cao, Wei; Li, Xinyu

2018-04-01

The influence of individual differences on learners' study time allocation has been emphasised in recent studies; however, little is known about the role of individual thinking styles (analytical versus intuitive). In the present study, we explored the influence of individual thinking styles on learners' application of agenda-based and habitual processes when selecting the first item during a study-time allocation task. A 3-item cognitive reflection test (CRT) was used to determine individuals' degree of cognitive reliance on intuitive versus analytical cognitive processing. Significant correlations between CRT scores and the choices of first item selection were observed in both Experiment 1a (study time was 5 seconds per triplet) and Experiment 1b (study time was 20 seconds per triplet). Furthermore, analytical decision makers constructed a value-based agenda (prioritised high-reward items), whereas intuitive decision makers relied more upon habitual responding (selected items from the leftmost of the array). The findings of Experiment 1a were replicated in Experiment 2 notwithstanding ruling out the possible effects from individual intelligence and working memory capacity. Overall, the individual thinking style plays an important role on learners' study time allocation and the predictive ability of CRT is reliable in learners' item selection strategy. © 2016 International Union of Psychological Science.

Systematic review of the literature and evidence-based recommendations for antibiotic prophylaxis in trauma: results from an Italian consensus of experts.

PubMed

Poole, Daniele; Chieregato, Arturo; Langer, Martin; Viaggi, Bruno; Cingolani, Emiliano; Malacarne, Paolo; Mengoli, Francesca; Nardi, Giuseppe; Nascimben, Ennio; Riccioni, Luigi; Turriziani, Ilaria; Volpi, Annalisa; Coniglio, Carlo; Gordini, Giovanni

2014-01-01

Antibiotic prophylaxis is frequently administered in severe trauma. However, the risk of selecting resistant bacteria, a major issue especially in critical care environments, has not been sufficiently investigated. The aim of the present study was to provide guidelines for antibiotic prophylaxis for four different trauma-related clinical conditions, taking into account the risks of antibiotic-resistant bacteria selection, thus innovating previous guidelines in the field. The MEDLINE database was searched for studies comparing antibiotic prophylaxis to controls (placebo or no antibiotic administration) in four clinical traumatic conditions that were selected on the basis of the traumatic event frequency and/or infection severity. The selected studies focused on the prevention of early ventilator associated pneumonia (VAP) in comatose patients with traumatic brain injury, of meningitis in severe basilar skull fractures, of wound infections in long-bone open fractures. Since no placebo-controlled study was available for deep surgical site-infections prevention in abdominal trauma with enteric contamination, we compared 24-hour and 5-day antibiotic prophylaxis policies. A separate specific research focused on the question of antibiotic-resistant bacteria selection caused by antibiotic prophylaxis, an issue not adequately investigated by the selected studies. Randomised trials, reviews, meta-analyses, observational studies were included. Data extraction was carried out by one author according to a predefined protocol, using an electronic form. The strength of evidence was stratified and recommendations were given according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) criteria. Uncertain evidence deserving further studies was found for two-dose antibiotic prophylaxis for early VAP prevention in comatose patients. In the other cases the risk of resistant-bacteria selection caused by antibiotic administration for 48 hours or more, outweighed potential benefits. When accounting for antibiotic-resistant bacteria selection we found no evidence in favour of antibiotic prophylaxis lasting two or more days in the studied clinical conditions.

Methodology Series Module 3: Cross-sectional Studies.

PubMed

Setia, Maninder Singh

2016-01-01

Cross-sectional study design is a type of observational study design. In a cross-sectional study, the investigator measures the outcome and the exposures in the study participants at the same time. Unlike in case-control studies (participants selected based on the outcome status) or cohort studies (participants selected based on the exposure status), the participants in a cross-sectional study are just selected based on the inclusion and exclusion criteria set for the study. Once the participants have been selected for the study, the investigator follows the study to assess the exposure and the outcomes. Cross-sectional designs are used for population-based surveys and to assess the prevalence of diseases in clinic-based samples. These studies can usually be conducted relatively faster and are inexpensive. They may be conducted either before planning a cohort study or a baseline in a cohort study. These types of designs will give us information about the prevalence of outcomes or exposures; this information will be useful for designing the cohort study. However, since this is a 1-time measurement of exposure and outcome, it is difficult to derive causal relationships from cross-sectional analysis. We can estimate the prevalence of disease in cross-sectional studies. Furthermore, we will also be able to estimate the odds ratios to study the association between exposure and the outcomes in this design.

Methodology Series Module 3: Cross-sectional Studies

PubMed Central

Setia, Maninder Singh

2016-01-01

Cross-sectional study design is a type of observational study design. In a cross-sectional study, the investigator measures the outcome and the exposures in the study participants at the same time. Unlike in case–control studies (participants selected based on the outcome status) or cohort studies (participants selected based on the exposure status), the participants in a cross-sectional study are just selected based on the inclusion and exclusion criteria set for the study. Once the participants have been selected for the study, the investigator follows the study to assess the exposure and the outcomes. Cross-sectional designs are used for population-based surveys and to assess the prevalence of diseases in clinic-based samples. These studies can usually be conducted relatively faster and are inexpensive. They may be conducted either before planning a cohort study or a baseline in a cohort study. These types of designs will give us information about the prevalence of outcomes or exposures; this information will be useful for designing the cohort study. However, since this is a 1-time measurement of exposure and outcome, it is difficult to derive causal relationships from cross-sectional analysis. We can estimate the prevalence of disease in cross-sectional studies. Furthermore, we will also be able to estimate the odds ratios to study the association between exposure and the outcomes in this design. PMID:27293245

The effects of recall errors and of selection bias in epidemiologic studies of mobile phone use and cancer risk.

PubMed

Vrijheid, Martine; Deltour, Isabelle; Krewski, Daniel; Sanchez, Marie; Cardis, Elisabeth

2006-07-01

This paper examines the effects of systematic and random errors in recall and of selection bias in case-control studies of mobile phone use and cancer. These sensitivity analyses are based on Monte-Carlo computer simulations and were carried out within the INTERPHONE Study, an international collaborative case-control study in 13 countries. Recall error scenarios simulated plausible values of random and systematic, non-differential and differential recall errors in amount of mobile phone use reported by study subjects. Plausible values for the recall error were obtained from validation studies. Selection bias scenarios assumed varying selection probabilities for cases and controls, mobile phone users, and non-users. Where possible these selection probabilities were based on existing information from non-respondents in INTERPHONE. Simulations used exposure distributions based on existing INTERPHONE data and assumed varying levels of the true risk of brain cancer related to mobile phone use. Results suggest that random recall errors of plausible levels can lead to a large underestimation in the risk of brain cancer associated with mobile phone use. Random errors were found to have larger impact than plausible systematic errors. Differential errors in recall had very little additional impact in the presence of large random errors. Selection bias resulting from underselection of unexposed controls led to J-shaped exposure-response patterns, with risk apparently decreasing at low to moderate exposure levels. The present results, in conjunction with those of the validation studies conducted within the INTERPHONE study, will play an important role in the interpretation of existing and future case-control studies of mobile phone use and cancer risk, including the INTERPHONE study.

Early generation selection results from a two year, six location study

USDA-ARS?s Scientific Manuscript database

In potato breeding programs, early generation selections are rarely evaluated in multiple environments because of limited seed quantities. By the time seed quantities are available, few clones remain from the original population. The purpose of this study was to allow multiple locations to select ...

Selecting Cases for Intensive Analysis: A Diversity of Goals and Methods

ERIC Educational Resources Information Center

Gerring, John; Cojocaru, Lee

2016-01-01

This study revisits the task of case selection in case study research, proposing a new typology of strategies that is explicit, disaggregated, and relatively comprehensive. A secondary goal is to explore the prospects for case selection by "algorithm," aka "ex ante," "automatic," "quantitative,"…

We Have a Choice: Students at Risk of Leaving Chicago Public Schools. A Report to the Chicago Board of Education and the Illinois Attorney General.

ERIC Educational Resources Information Center

Kyle, Charles L.; And Others

This report presents findings from a study of dropouts and students at risk in Chicago public schools. It is divided into five major chapters. Chapter 1 describes the study's grouping of Chicago high schools into four "types": selective academic; selective vocational; non-selective integrated; and non-selective segregated. A…

Selection and stopping in voluntary action: A meta-analysis and combined fMRI study☆

PubMed Central

Rae, Charlotte L.; Hughes, Laura E.; Weaver, Chelan; Anderson, Michael C.; Rowe, James B.

2014-01-01

Voluntary action control requires selection of appropriate responses and stopping of inappropriate responses. Selection and stopping are often investigated separately, but they appear to recruit similar brain regions, including the pre-supplementary motor area (preSMA) and inferior frontal gyrus. We therefore examined the evidence for overlap of selection and stopping using two approaches: a meta-analysis of existing studies of selection and stopping, and a novel within-subject fMRI study in which action selection and a stop signal task were combined factorially. The novel fMRI study also permitted us to investigate hypotheses regarding a common mechanism for selection and stopping. The preSMA was identified by both methods as common to selection and stopping. However, stopping a selected action did not recruit preSMA more than stopping a specified action, nor did stop signal reaction times differ significantly across the two conditions. These findings suggest that the preSMA supports both action selection and stopping, but the two processes may not require access to a common inhibition mechanism. Instead, the preSMA might represent information about potential actions that is used in both action selection and stopping in order to resolve conflict between competing available responses. PMID:24128740

Exploring Selective Exposure and Confirmation Bias as Processes Underlying Employee Work Happiness: An Intervention Study

PubMed Central

Williams, Paige; Kern, Margaret L.; Waters, Lea

2016-01-01

Employee psychological capital (PsyCap), perceptions of organizational virtue (OV), and work happiness have been shown to be associated within and over time. This study examines selective exposure and confirmation bias as potential processes underlying PsyCap, OV, and work happiness associations. As part of a quasi-experimental study design, school staff (N = 69) completed surveys at three time points. After the first assessment, some staff (n = 51) completed a positive psychology training intervention. Results of descriptive statistics, correlation, and regression analyses on the intervention group provide some support for selective exposure and confirmation bias as explanatory mechanisms. In focusing on the processes through which employee attitudes may influence work happiness this study advances theoretical understanding, specifically of selective exposure and confirmation bias in a field study context. PMID:27378978

Measuring food intake in studies of obesity.

PubMed

Lissner, Lauren

2002-12-01

The problem of how to measure habitual food intake in studies of obesity remains an enigma in nutritional research. The existence of obesity-specific underreporting was rather controversial until the advent of the doubly labelled water technique gave credence to previously anecdotal evidence that such a bias does in fact exist. This paper reviews a number of issues relevant to interpreting dietary data in studies involving obesity. Topics covered include: participation biases, normative biases,importance of matching method to study, selective underreporting, and a brief discussion of the potential implications of generalised and selective underreporting in analytical epidemiology. It is concluded that selective underreporting of certain food types by obese individuals would produce consequences in analytical epidemiological studies that are both unpredictable and complex. Since it is becoming increasingly acknowledged that selective reporting error does occur, it is important to emphasise that correction for energy intake is not sufficient to eliminate the biases from this type of error. This is true both for obesity-related selective reporting errors and more universal types of selective underreporting, e.g. foods of low social desirability. Additional research is urgently required to examine the consequences of this type of error.

Effects of medical school selection on student motivation: a PhD thesis report.

PubMed

Wouters, Anouk

2018-02-01

High stakes are involved in student selection, for both medical schools and applicants. This thesis investigated the effects of selection on the medical student population and applicant pool in the Dutch setting. This thesis consists of six papers: two quantitative studies, one qualitative study, two mixed methods studies and one perspective paper based on a review of the literature. (1) Compared with a lottery, selection does not result in a student population with better motivation, engagement and performance, both in the clinical and pre-clinical phases of the study. (2) Selection seems to have a temporary stimulating effect on student motivation through enhancing perceived autonomy, competence and relatedness. (3) Applicants adopt a strategic approach, based on the selection procedure, in their choice of medical school. (4) The description of an applicant's motivation is not a reliable and valid tool to assess motivation during selection. (5) Gaining healthcare experience is crucial for applicants' motivation, but inequalities in access to such experiences can demotivate certain student groups from applying to medical school. (6) The gains yielded from selection compared with a lottery seem to be small. Unintentionally induced self-selection among certain groups of students and biased selection procedures may compromise student diversity. The added value of selection procedures compared with a weighted lottery for admitting students to medical school is questionable. Students are generally motivated and perform well, irrespective of how they enrolled in medical school. Selection yields only small gains, while student diversity may be hampered.

29 CFR 1607.7 - Use of other validity studies.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 29 Labor 4 2011-07-01 2011-07-01 false Use of other validity studies. 1607.7 Section 1607.7 Labor... EMPLOYEE SELECTION PROCEDURES (1978) General Principles § 1607.7 Use of other validity studies. A. Validity studies not conducted by the user. Users may, under certain circumstances, support the use of selection...

A Mixed Methods Sampling Methodology for a Multisite Case Study

ERIC Educational Resources Information Center

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

2012-01-01

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

Immiscible fluid: Heat of fusion heat storage system

NASA Technical Reports Server (NTRS)

Edie, D. D.; Melsheimer, S. S.; Mullins, J. C.

1980-01-01

Both heat and mass transfer in direct contact aqueous crystallizing systems were studied as part of a program desig- ned to evaluate the feasibility of direct contact heat transfer in phase change storage using aqueous salt system. Major research areas, discussed include (1) crystal growth velocity study on selected salts; (2) selection of salt solutions; (3) selection of immiscible fluids; (4) studies of heat transfer and system geometry; and (5) system demonstration.

Data book: Space station/base food system study. Book 3: Study selection rationale sheets

NASA Technical Reports Server (NTRS)

1970-01-01

The supporting rationale sheets are presented which were utilized in the selection and support of the concepts considered in the final phase of the study. Each concept, conceived to fulfill a specific function of the food system, was assessed in terms of the eight critical factors depicted on the rationale sheet. When weighted and totaled, the resulting selection factor was used as a guide in making the final decision.

Study of the Decision-Making Procedures for the Acquisition of Science Library Materials and the Relation of These Procedures to the Requirements of College and University Library Patrons.

ERIC Educational Resources Information Center

Lane, David O.

The idea that there was a need for formal study of the methods by which titles are selected for addition to the collections of academic science libraries resulted in this investigation of the selection processes of these libraries. Specifically, the study concentrates on the selection procedures in three sciences: biology, chemistry, and physics.…

Vocational Preferences and College Expectations: An Extension of Holland's Principle of Self-Selection

ERIC Educational Resources Information Center

Pike, Gary R.

2006-01-01

Holland's theory of vocational preferences provides a powerful framework for studying students' college experiences. A basic proposition of Holland's theory is that individuals actively seek out and select environments that are congruent with their personality types. Although studies consistently support the self-selection proposition, they have…

An Assessment of Teacher Trainees' Attitudes toward Selected Instructional Media.

ERIC Educational Resources Information Center

Koontz, Franklin R.

This quantitative, descriptive research study measured the attitudes of preservice teachers toward the selection and use of instructional media in the classroom. Two groups were involved in the study: approximately 168 students enrolled in formal training in the selection and utilization of instructional media, and approximately 170 preservice…

Collaborative Textbook Selection: A Case Study Leading to Practical and Theoretical Considerations

ERIC Educational Resources Information Center

Czerwionka, Lori; Gorokhovsky, Bridget

2015-01-01

This case study developed a collaborative approach to the selection of a Spanish language textbook. The collaborative process consisted of six steps, detailed in this article: team building, generating evaluation criteria, formulating a meaningful rubric, selecting prospective textbooks, calculating rubric results, and reflectively reviewing…

Home Environment of Selected Filipino Gifted Individuals

ERIC Educational Resources Information Center

Pawilen, Greg Tabios

2018-01-01

This study investigated the home environment of selected Filipino gifted individuals. It aims to answer two research questions: (1) what is the giftedness profile of the selected Filipino gifted?; (2) what types of home environments do Filipino gifted have? This study uses qualitative methods, specifically narrative research strategy, to provide a…

Selective advantage of implementing optimal contributions selection and timescales for the convergence of long-term genetic contributions.

PubMed

Howard, David M; Pong-Wong, Ricardo; Knap, Pieter W; Kremer, Valentin D; Woolliams, John A

2018-05-10

Optimal contributions selection (OCS) provides animal breeders with a framework for maximising genetic gain for a predefined rate of inbreeding. Simulation studies have indicated that the source of the selective advantage of OCS is derived from breeding decisions being more closely aligned with estimates of Mendelian sampling terms ([Formula: see text]) of selection candidates, rather than estimated breeding values (EBV). This study represents the first attempt to assess the source of the selective advantage provided by OCS using a commercial pig population and by testing three hypotheses: (1) OCS places more emphasis on [Formula: see text] compared to EBV for determining which animals were selected as parents, (2) OCS places more emphasis on [Formula: see text] compared to EBV for determining which of those parents were selected to make a long-term genetic contribution (r), and (3) OCS places more emphasis on [Formula: see text] compared to EBV for determining the magnitude of r. The population studied also provided an opportunity to investigate the convergence of r over time. Selection intensity limited the number of males available for analysis, but females provided some evidence that the selective advantage derived from applying an OCS algorithm resulted from greater weighting being placed on [Formula: see text] during the process of decision-making. Male r were found to converge initially at a faster rate than female r, with approximately 90% convergence achieved within seven generations across both sexes. This study of commercial data provides some support to results from theoretical and simulation studies that the source of selective advantage from OCS comes from [Formula: see text]. The implication that genomic selection (GS) improves estimation of [Formula: see text] should allow for even greater genetic gains for a predefined rate of inbreeding, once the synergistic benefits of combining OCS and GS are realised.

Evolution of divergent female mating preference in response to experimental sexual selection.

PubMed

Debelle, Allan; Ritchie, Michael G; Snook, Rhonda R

2014-09-01

Sexual selection is predicted to drive the coevolution of mating signals and preferences (mating traits) within populations, and could play a role in speciation if sexual isolation arises due to mating trait divergence between populations. However, few studies have demonstrated that differences in mating traits between populations result from sexual selection alone. Experimental evolution is a promising approach to directly examine the action of sexual selection on mating trait divergence among populations. We manipulated the opportunity for sexual selection (low vs. high) in populations of Drosophila pseudoobscura. Previous studies on these experimental populations have shown that sexual selection manipulation resulted in the divergence between sexual selection treatments of several courtship song parameters, including interpulse interval (IPI) which markedly influences male mating success. Here, we measure female preference for IPI using a playback design to test for preference divergence between the sexual selection treatments after 130 generations of experimental sexual selection. The results suggest that female preference has coevolved with male signal, in opposite directions between the sexual selection treatments, providing direct evidence of the ability of sexual selection to drive the divergent coevolution of mating traits between populations. We discuss the implications in the context sexual selection and speciation. © 2014 The Authors. Evolution published by Wiley Periodicals, Inc. on behalf of The Society for the Study of Evolution.

Limits to behavioral evolution: the quantitative genetics of a complex trait under directional selection.

PubMed

Careau, Vincent; Wolak, Matthew E; Carter, Patrick A; Garland, Theodore

2013-11-01

Replicated selection experiments provide a powerful way to study how "multiple adaptive solutions" may lead to differences in the quantitative-genetic architecture of selected traits and whether this may translate into differences in the timing at which evolutionary limits are reached. We analyze data from 31 generations (n=17,988) of selection on voluntary wheel running in house mice. The rate of initial response, timing of selection limit, and height of the plateau varied significantly between sexes and among the four selected lines. Analyses of litter size and realized selection differentials seem to rule out counterposing natural selection as a cause of the selection limits. Animal-model analyses showed that although the additive genetic variance was significantly lower in selected than control lines, both before and after the limits, the decrease was not sufficient to explain the limits. Moreover, directional selection promoted a negative covariance between additive and maternal genetic variance over the first 10 generations. These results stress the importance of replication in selection studies of higher-level traits and highlight the fact that long-term predictions of response to selection are not necessarily expected to be linear because of the variable effects of selection on additive genetic variance and maternal effects. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

Goal selection versus process control while learning to use a brain-computer interface

NASA Astrophysics Data System (ADS)

Royer, Audrey S.; Rose, Minn L.; He, Bin

2011-06-01

A brain-computer interface (BCI) can be used to accomplish a task without requiring motor output. Two major control strategies used by BCIs during task completion are process control and goal selection. In process control, the user exerts continuous control and independently executes the given task. In goal selection, the user communicates their goal to the BCI and then receives assistance executing the task. A previous study has shown that goal selection is more accurate and faster in use. An unanswered question is, which control strategy is easier to learn? This study directly compares goal selection and process control while learning to use a sensorimotor rhythm-based BCI. Twenty young healthy human subjects were randomly assigned either to a goal selection or a process control-based paradigm for eight sessions. At the end of the study, the best user from each paradigm completed two additional sessions using all paradigms randomly mixed. The results of this study were that goal selection required a shorter training period for increased speed, accuracy, and information transfer over process control. These results held for the best subjects as well as in the general subject population. The demonstrated characteristics of goal selection make it a promising option to increase the utility of BCIs intended for both disabled and able-bodied users.

Drug product selection: the Florida experience.

PubMed Central

Vuturo, G J; Krischer, J P; McCormick, W C

1980-01-01

Drug product selection, the act of selecting and dispensing a lower cost generically equivalent product to that prescribed, is made possible in 46 states through recently enacted legislation. Florida's legislation is unique in that it requires pharmacists to product select under certain circumstances. This study reports on the results of a review of the Florida experience approximately one year after enactment of its drug product selection legislation. Nearly 132,000 prescriptions were sampled from 60 pharmacies during a four-month study period. This represents one per cent of all new prescriptions in the state and a three per cent sample of community pharmacies. Study results indicate that drug product selection on the average saves the consumer $1.92 per prescription. Further, under the provisions of this law the majority of cost savings (average reductions in acquisition costs between prescribed and dispensed products) are being passed along as savings to the consumer. During the four-month study period this amounted to a total prescription cost savings of nearly $425,000. Drug product selection occurs in approximately two per cent of all new prescriptions which compares favorably with results reported from other states but also suggests that additional savings can be realized under such legislation. PMID:7377418

Lesbian couples' views about and experiences of not being able to choose their sperm donor.

PubMed

Ravelingien, A; Provoost, V; Wyverkens, E; Buysse, A; De Sutter, P; Pennings, G

2015-01-01

In this qualitative study, we explore how lesbian recipients view and experience the selection of their anonymous sperm donor. The study was conducted in Belgium, where fertility centres follow a legal protocol that severely restricts personal choice in donor selection. While previous studies have shown that recipients want greater control and input in the selection of their sperm donor, this was not a main concern for most women in the present study. They generally acknowledged their lack of control on the selection outcome and accepted this as part and parcel of an anonymous donation policy that provides an opportunity to have a child. They actively and passively downplayed initial concerns about the donor selection procedure and felt they did not have or need a right to further control over the donor selection. In adopting this 'subordinate' position, they felt they should trust the hospital, which they hoped would fulfil rather high screening standards. Those who did want more choice were nuanced and careful about their motivations: they focused on selecting traits that would facilitate normal child development or increase family coherence. The findings shed light on how these patients perceive their position in this third-party reproduction setting.

Does Self-Selection Affect Samples’ Representativeness in Online Surveys? An Investigation in Online Video Game Research

PubMed Central

van Singer, Mathias; Chatton, Anne; Achab, Sophia; Zullino, Daniele; Rothen, Stephane; Khan, Riaz; Billieux, Joel; Thorens, Gabriel

2014-01-01

Background The number of medical studies performed through online surveys has increased dramatically in recent years. Despite their numerous advantages (eg, sample size, facilitated access to individuals presenting stigmatizing issues), selection bias may exist in online surveys. However, evidence on the representativeness of self-selected samples in online studies is patchy. Objective Our objective was to explore the representativeness of a self-selected sample of online gamers using online players’ virtual characters (avatars). Methods All avatars belonged to individuals playing World of Warcraft (WoW), currently the most widely used online game. Avatars’ characteristics were defined using various games’ scores, reported on the WoW’s official website, and two self-selected samples from previous studies were compared with a randomly selected sample of avatars. Results We used scores linked to 1240 avatars (762 from the self-selected samples and 478 from the random sample). The two self-selected samples of avatars had higher scores on most of the assessed variables (except for guild membership and exploration). Furthermore, some guilds were overrepresented in the self-selected samples. Conclusions Our results suggest that more proficient players or players more involved in the game may be more likely to participate in online surveys. Caution is needed in the interpretation of studies based on online surveys that used a self-selection recruitment procedure. Epidemiological evidence on the reduced representativeness of sample of online surveys is warranted. PMID:25001007

Optimized probability sampling of study sites to improve generalizability in a multisite intervention trial.

PubMed

Kraschnewski, Jennifer L; Keyserling, Thomas C; Bangdiwala, Shrikant I; Gizlice, Ziya; Garcia, Beverly A; Johnston, Larry F; Gustafson, Alison; Petrovic, Lindsay; Glasgow, Russell E; Samuel-Hodge, Carmen D

2010-01-01

Studies of type 2 translation, the adaption of evidence-based interventions to real-world settings, should include representative study sites and staff to improve external validity. Sites for such studies are, however, often selected by convenience sampling, which limits generalizability. We used an optimized probability sampling protocol to select an unbiased, representative sample of study sites to prepare for a randomized trial of a weight loss intervention. We invited North Carolina health departments within 200 miles of the research center to participate (N = 81). Of the 43 health departments that were eligible, 30 were interested in participating. To select a representative and feasible sample of 6 health departments that met inclusion criteria, we generated all combinations of 6 from the 30 health departments that were eligible and interested. From the subset of combinations that met inclusion criteria, we selected 1 at random. Of 593,775 possible combinations of 6 counties, 15,177 (3%) met inclusion criteria. Sites in the selected subset were similar to all eligible sites in terms of health department characteristics and county demographics. Optimized probability sampling improved generalizability by ensuring an unbiased and representative sample of study sites.

Birth order and sibship size: evaluation of the role of selection bias in a case-control study of non-Hodgkin's lymphoma.

PubMed

Mensah, F K; Willett, E V; Simpson, J; Smith, A G; Roman, E

2007-09-15

Substantial heterogeneity has been observed among case-control studies investigating associations between non-Hodgkin's lymphoma and familial characteristics, such as birth order and sibship size. The potential role of selection bias in explaining such heterogeneity is considered within this study. Selection bias according to familial characteristics and socioeconomic status is investigated within a United Kingdom-based case-control study of non-Hodgkin's lymphoma diagnosed during 1998-2001. Reported distributions of birth order and maternal age are each compared with expected reference distributions derived using national birth statistics from the United Kingdom. A method is detailed in which yearly data are used to derive expected distributions, taking account of variability in birth statistics over time. Census data are used to reweight both the case and control study populations such that they are comparable with the general population with regard to socioeconomic status. The authors found little support for an association between non-Hodgkin's lymphoma and birth order or family size and little evidence for an influence of selection bias. However, the findings suggest that between-study heterogeneity could be explained by selection biases that influence the demographic characteristics of participants.

Methodology Series Module 2: Case-control Studies.

PubMed

Setia, Maninder Singh

2016-01-01

Case-Control study design is a type of observational study. In this design, participants are selected for the study based on their outcome status. Thus, some participants have the outcome of interest (referred to as cases), whereas others do not have the outcome of interest (referred to as controls). The investigator then assesses the exposure in both these groups. The investigator should define the cases as specifically as possible. Sometimes, definition of a disease may be based on multiple criteria; thus, all these points should be explicitly stated in case definition. An important aspect of selecting a control is that they should be from the same 'study base' as that of the cases. We can select controls from a variety of groups. Some of them are: General population; relatives or friends; and hospital patients. Matching is often used in case-control control studies to ensure that the cases and controls are similar in certain characteristics, and it is a useful technique to increase the efficiency of the study. Case-Control studies can usually be conducted relatively faster and are inexpensive - particularly when compared with cohort studies (prospective). It is useful to study rare outcomes and outcomes with long latent periods. This design is not very useful to study rare exposures. Furthermore, they may also be prone to certain biases - selection bias and recall bias.

Recurrent personality dimensions in inclusive lexical studies: indications for a big six structure.

PubMed

Saucier, Gerard

2009-10-01

Previous evidence for both the Big Five and the alternative six-factor model has been drawn from lexical studies with relatively narrow selections of attributes. This study examined factors from previous lexical studies using a wider selection of attributes in 7 languages (Chinese, English, Filipino, Greek, Hebrew, Spanish, and Turkish) and found 6 recurrent factors, each with common conceptual content across most of the studies. The previous narrow-selection-based six-factor model outperformed the Big Five in capturing the content of the 6 recurrent wideband factors. Adjective markers of the 6 recurrent wideband factors showed substantial incremental prediction of important criterion variables over and above the Big Five. Correspondence between wideband 6 and narrowband 6 factors indicate they are variants of a "Big Six" model that is more general across variable-selection procedures and may be more general across languages and populations.

Institutional Efficiency in Selected Universities in Uganda

ERIC Educational Resources Information Center

Amina, Nakimuli; Turyahebwa, Abanis

2015-01-01

Universities are accountable This study looked into Institutional Efficiency in selected Universities in Central Uganda. The study was guided by the following objectives; Determine the level of institutional efficiency of the universities in terms of educational efficiency; research efficiency and community service efficiency. The study employed…

Environmental ethics and wilderness management: an empirical study

Treesearch

William A. Valliere; Robert E. Manning

1995-01-01

The underlying hypothesis of this study is that environmental ethics influence public attitudes toward wilderness management. To study this hypothesis, environmental ethics were defined, categorized, and measured empirically. Additionally, attitudes toward selected wilderness management issues were measured. Associations were found between beliefs in selected...

Diagnostic performance of contrast-enhanced spectral mammography: Systematic review and meta-analysis.

PubMed

Tagliafico, Alberto Stefano; Bignotti, Bianca; Rossi, Federica; Signori, Alessio; Sormani, Maria Pia; Valdora, Francesca; Calabrese, Massimo; Houssami, Nehmat

2016-08-01

To estimate sensitivity and specificity of CESM for breast cancer diagnosis. Systematic review and meta-analysis of the accuracy of CESM in finding breast cancer in highly selected women. We estimated summary receiver operating characteristic curves, sensitivity and specificity according to quality criteria with QUADAS-2. Six hundred four studies were retrieved, 8 of these reporting on 920 patients with 994 lesions, were eligible for inclusion. Estimated sensitivity from all studies was: 0.98 (95% CI: 0.96-1.00). Specificity was estimated from six studies reporting raw data: 0.58 (95% CI: 0.38-0.77). The majority of studies were scored as at high risk of bias due to the very selected populations. CESM has a high sensitivity but very low specificity. The source studies were based on highly selected case series and prone to selection bias. High-quality studies are required to assess the accuracy of CESM in unselected cases. Copyright © 2016 Elsevier Ltd. All rights reserved.

Synthesis and Ion-Exchange Properties of Graphene Th(IV) Phosphate Composite Cation Exchanger: Its Applications in the Selective Separation of Lead Metal Ions

PubMed Central

Rangreez, Tauseef Ahmad; Alhogbi, Basma G.; Naushad, Mu.

2017-01-01

In this study, graphene Th(IV) phosphate was prepared by sol–gel precipitation method. The ion-exchange behavior of this cation-exchanger was studied by investigating properties like ion-exchange capacity for various metal ions, the effect of eluent concentration, elution behavior, and thermal effect on ion-exchange capacity (IEC). Several physicochemical properties as Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) study, thermal studies, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) studies were also carried out. The material possessed an IEC of 1.56 meq·dry·g−1 of the exchanger and was found to be nano-composite. The selectivity studies showed that the material is selective towards Pb(II) ions. The selectivity of this cation-exchanger was demonstrated in the binary separation of Pb(II) ions from mixture with other metal ions. The recovery was found to be both quantitative and reproducible. PMID:28737717

School Transitions: A Qualitative Study of the Supports Provided by Washington State Special Education Administrators

ERIC Educational Resources Information Center

Lewinsohn, Kari

2013-01-01

This study investigated the role of special education administrators in the transition planning process for children with disabilities ages 3-21 in selected Washington school districts. A basic qualitative study was selected to construct meaning from a described phenomenon. The study sought to identify and explain how special education…

Effects of Selected Meditative Asanas on Kinaesthetic Perception and Speed of Movement

ERIC Educational Resources Information Center

Singh, Kanwaljeet; Bal, Baljinder S.; Deol, Nishan S.

2009-01-01

Study aim: To assess the effects of selected meditative "asanas" on kinesthetic perception and movement speed. Material and methods: Thirty randomly selected male students aged 18-24 years volunteered to participate in the study. They were randomly assigned into two groups: A (medidative) and B (control). The Nelson's movement speed and…

Designing Intervention Studies: Selected Populations, Range Restrictions, and Statistical Power

ERIC Educational Resources Information Center

Miciak, Jeremy; Taylor, W. Pat; Stuebing, Karla K.; Fletcher, Jack M.; Vaughn, Sharon

2016-01-01

An appropriate estimate of statistical power is critical for the design of intervention studies. Although the inclusion of a pretest covariate in the test of the primary outcome can increase statistical power, samples selected on the basis of pretest performance may demonstrate range restriction on the selection measure and other correlated…

Failed Regulations and School Composition: Selective Admission Practices in Chilean Primary Schools

ERIC Educational Resources Information Center

Carrasco, Alejandro; Gutiérrez, Gabriel; Flores, Carolina

2017-01-01

This is an exploratory study about pupil selection. Admission regulations are central to understanding issues of school mix, segregation and educational justice. In Chile, student selection has been intensively discussed but scarcely studied. Using a questionnaire for headteachers (N = 581), we explore how school admission processes are organised…

Reboot: Revisiting Factors Influencing Female Selection of the CIS Major

ERIC Educational Resources Information Center

Hodges, Darin; Corley, Ken

2017-01-01

A concern among many universities, this study reflects and continues research on the changing attitude and intent of selecting a Computer Information Systems major. Focusing on the gender gap for selection of major for women in this field, studies indicate instrumental beliefs and subjective norms can influence behavior and indicate how selection…

A Multi-Site Study on Medical School Selection, Performance, Motivation and Engagement

ERIC Educational Resources Information Center

Wouters, A.; Croiset, G.; Schripsema, N. R.; Cohen-Schotanus, J.; Spaai, G. W.; Hulsman, R. L.; Kusurkar, R. A.

2017-01-01

Medical schools seek ways to improve their admissions strategies, since the available methods prove to be suboptimal for selecting the best and most motivated students. In this multi-site cross-sectional questionnaire study, we examined the value of (different) selection procedures compared to a weighted lottery procedure, which includes direct…

Computer Use of a Medical Dictionary to Select Search Words.

ERIC Educational Resources Information Center

O'Connor, John

1986-01-01

Explains an experiment in text-searching retrieval for cancer questions which developed and used computer procedures (via human simulation) to select search words from medical dictionaries. This study is based on an earlier one in which search words were humanly selected, and the recall results of the two studies are compared. (Author/LRW)

Analysis of Manager Selection and Appointment to Educational Organizations Process in Turkey

ERIC Educational Resources Information Center

Yard?b?, Nursel; Küçük, Fazil

2015-01-01

This study's aim is that to determine the requirements for school principals' selection and assignment conditions and to present these requirements' effects. Qualitative research design was used in this research, and also this study is content analysis research. School principals' selection and assignment conditions in Regulations between the…

The Evaluation and Selection of a Fifth Ground Antenna Site for the Global Positioning System.

DTIC Science & Technology

1987-12-07

selection was the region between Australia and South America and north of the Antartic . Using the performance results of this study, further study...indicated that the best region for selection was between Australia and South America and north of the Antartic . Using the performance results of this

A Retrospective View of Selective Admission of Physical Therapist Assistants.

ERIC Educational Resources Information Center

Pape, C. Dale; Casey, John P.

1986-01-01

This study was an attempt to evaluate how well a specific selection formula for admission to a physical therapist assistant program worked. It compared the relative selective admission score with the clinical and academic success of those students who completed the course of study; this necessitated a retrospective analysis. (Author/CT)

Selective Learning and Teaching among Japanese and German Children

ERIC Educational Resources Information Center

Kim, Sunae; Paulus, Markus; Sodian, Beate; Itakura, Shoji; Ueno, Mika; Senju, Atsushi; Proust, Joëlle

2018-01-01

Despite an increasing number of studies demonstrating that young children selectively learn from others, and a few studies of children's selective teaching, the evidence almost exclusively comes from Western cultures, and cross-cultural comparison in this line of work is very rare. In the present research, we investigated Japanese and German…

Teaching College Courses in Selected Correctonal Facilities in the Commonwealth of Virginia

ERIC Educational Resources Information Center

Barringer-Brown, Charletta Hope

2015-01-01

Numerous research studies have focused on recidivism rates ignoring education to inmates as a technique of reducing recidivism. This qualitative study investigates the faculty perception of teaching in selected correctional facilities. A sample of fifty-three faculty members teaching within four selected correctional facilities within a 60 mile…

Honors Selection Study 1966-67.

ERIC Educational Resources Information Center

Neidich, Alan

Because many of the students selected for participation in the University of South Carolina's College of Arts and Science Honors Program failed to attain the minimal grade point level required to remain in the program, the Counseling Bureau undertook an evaluative study to improve selection methods. The project aimed to find answers to 3…

Executive Selection: A Research Report on What Works and What Doesn't.

ERIC Educational Resources Information Center

Sessa, Valerie I.; Kaiser, Robert; Taylor, Jodi K.; Campbell, Richard J.

This book presents a study that examined the apparent failures of many top-level executive selections. For the study, information was gathered from 494 top executives. The research's purpose was to determine how executives are defined as successful or unsuccessful, how executive selection takes place in modern organizations, and what determines…

The Impact of Presentation Format on Younger and Older Adults' Self-Regulated Learning.

PubMed

Price, Jodi

2017-01-01

Background/Study Context: Self-regulated learning involves deciding what to study and for how long. Debate surrounds whether individuals' selections are influenced more by item complexity, point values, or if instead people select in a left-to-right reading order, ignoring item complexity and value. The present study manipulated whether point values and presentation format favored selection of simple or complex Chinese-English pairs to assess the impact on younger and older adults' selection behaviors. One hundred and five younger (M age  = 20.26, SD = 2.38) and 102 older adults (M age  = 70.28, SD = 6.37) participated in the experiment. Participants studied four different 3 × 3 grids (two per trial), each containing three simple, three medium, and three complex Chinese-English vocabulary pairs presented in either a simple-first or complex-first order, depending on condition. Point values were assigned in either a 2-4-8 or 8-4-2 order so that either simple or complex items were favored. Points did not influence the order in which either age group selected items, whereas presentation format did. Younger and older adults selected more simple or complex items when they appeared in the first column. However, older adults selected and allocated more time to simpler items but recalled less overall than did younger adults. Memory beliefs and working memory capacity predicted study time allocation, but not item selection, behaviors. Presentation format must be considered when evaluating which theory of self-regulated learning best accounts for younger and older adults' study behaviors and whether there are age-related differences in self-regulated learning. The results of the present study combine with others to support the importance of also considering the role of external factors (e.g., working memory capacity and memory beliefs) in each age group's self-regulated learning decisions.

Moving a randomized clinical trial into an observational cohort.

PubMed

Goodman, Phyllis J; Hartline, Jo Ann; Tangen, Catherine M; Crowley, John J; Minasian, Lori M; Klein, Eric A; Cook, Elise D; Darke, Amy K; Arnold, Kathryn B; Anderson, Karen; Yee, Monica; Meyskens, Frank L; Baker, Laurence H

2013-02-01

The Selenium and Vitamin E Cancer Prevention Trial (SELECT) was a randomized, double-blind, placebo-controlled prostate cancer prevention study funded by the National Cancer Institute (NCI) and conducted by the Southwest Oncology Group (SWOG). A total of 35,533 men were assigned randomly to one of the four treatment groups (vitamin E + placebo, selenium + placebo, vitamin E + selenium, and placebo + placebo). The independent Data and Safety Monitoring Committee (DSMC) recommended the discontinuation of study supplements because of the lack of efficacy for risk reduction and because futility analyses demonstrated no possibility of benefit of the supplements to the anticipated degree (25% reduction in prostate cancer incidence) with additional follow-up. Study leadership agreed that the randomized trial should be terminated but believed that the cohort should be maintained and followed as the additional follow-up would contribute important information to the understanding of the biologic consequences of the intervention. Since the participants no longer needed to be seen in person to assess acute toxicities or to be given study supplements, it was determined that the most efficient and cost-effective way to follow them was via a central coordinated effort. A number of changes were necessary at the local Study Sites and SELECT Statistical Center to transition to following participants via a Central Coordinating Center. We describe the transition process from a randomized clinical trial to the observational Centralized Follow-Up (CFU) study. The process of transitioning SELECT, implemented at more than 400 Study Sites across the United States, Canada, and Puerto Rico, entailed many critical decisions and actions including updates to online documents such as the SELECT Workbench and Study Manual, a protocol amendment, reorganization of the Statistical Center, creation of a Transition Committee, development of materials for SELECT Study Sites, development of procedures to close Study Sites, and revision of data collection procedures and the process by which to contact participants. At the time of the publication of the primary SELECT results in December 2008, there were 32,569 men alive and currently active in the trial. As of 31 December 2011, 17,761 participants had been registered to the CFU study. This number is less than had been anticipated due to unforeseen difficulties with local Study Site institutional review boards (IRBs). However, from this cohort, we estimate that an additional 580 prostate cancer cases and 215 Gleason 7 or higher grade cancers will be identified. Over 109,000 individual items have been mailed to participants. Active SELECT ancillary studies have continued. The substantial SELECT biorepository is available to researchers; requests to use the specimens are reviewed for feasibility and scientific merit. As of April 2012, 12 proposals had been approved. The accrual goal of the follow-up study was not met, limiting our power to address the study objectives satisfactorily. The CFU study is also dependent on a number of factors including continued funding, continued interest of investigators in the biorepository, and the continued contribution of the participants. Our experience may be less pertinent to investigators who wish to follow participants in a treatment trial or participants in prevention trials in other medical areas. Extended follow-up of participants in prevention research is important to study the long-term effects of the interventions, such as those used in SELECT. The approach taken by SELECT investigators was to continue to follow participants centrally via an annual questionnaire and with a web-based option. The participants enrolled in the CFU study represent a large, well-characterized, generally healthy cohort. The CFU has enabled us to collect additional prostate and other cancer endpoints and longer follow-up on the almost 18,000 participants enrolled. The utility of the extensive biorepository that was developed during the course of the SELECT is enhanced by longer follow-up.

Moving a Randomized Clinical Trial into an Observational Cohort

PubMed Central

Goodman, Phyllis J.; Hartline, Jo Ann; Tangen, Catherine M.; Crowley, John J.; Minasian, Lori M.; Klein, Eric A.; Cook, Elise D.; Darke, Amy K.; Arnold, Kathryn B.; Anderson, Karen; Yee, Monica; Meyskens, Frank L.; Baker, Laurence H.

2013-01-01

Background The Selenium and Vitamin E Cancer Prevention Trial (SELECT) was a randomized, double blind, placebo-controlled prostate cancer prevention study funded by the National Cancer Institute and conducted by SWOG (Southwest Oncology Group). A total of 35,533 men were assigned randomly to one of four treatment groups (vitamin E + placebo, selenium + placebo, vitamin E + selenium, placebo + placebo. The independent Data and Safety Monitoring Committee recommended the discontinuation of study supplements because of the lack of efficacy for risk reduction and because futility analyses demonstrated no possibility of benefit of the supplements to the anticipated degree (25% reduction in prostate cancer incidence) with additional follow-up. Study leadership agreed that the randomized trial should be terminated but believed that the cohort should be maintained and followed as the additional follow-up would contribute important information to the understanding of the biologic consequences of the intervention. Since the participants no longer needed to be seen in person to assess acute toxicities or to be given study supplements, it was determined that the most efficient and cost-effective way to follow them was via a central coordinated effort. Purpose A number of changes were necessary at the local Study Sites and SELECT Statistical Center to transition to following participants via a Central Coordinating Center. We describe the transition process from a randomized clinical trial to the observational Centralized Follow-up (CFU) study. Methods The process of transitioning SELECT, implemented at more than 400 Study Sites across the United States, Canada and Puerto Rico, entailed many critical decisions and actions including updates to online documents such as the SELECT Workbench and Study Manual, a protocol amendment, reorganization of the Statistical Center, creation of a Transition Committee, development of materials for SELECT Study Sites, development of procedures to close Study Sites, and revision of data collection procedures and the process by which to contact participants. Results At the time of the publication of the primary SELECT results in December 2008, there were 32,569 men alive and currently active in the trial. As of December 31, 2011, 17,761 participants had been registered to the CFU study. This number is less than had been anticipated due to unforeseen difficulties with local Study Site IRBs. However, from this cohort we estimate that an additional 580 prostate cancer cases and 215 Gleason 7 or higher cancers will be identified. Over 109,000 individual items have been mailed to participants. Active SELECT ancillary studies have continued. The substantial SELECT biorepository is available to researchers; requests to use the specimens are reviewed for feasibility and scientific merit. As of April 2012, 12 proposals had been approved. Limitations The accrual goal of the follow-up study was not met, limiting our power to address the study objectives satisfactorily. The CFU study is also dependent on a number of factors including continued funding, continued interest of investigators in the biorepository and the continued contribution of the participants. Our experience may be less pertinent to investigators who wish to follow participants in a treatment trial or participants in prevention trials in other medical areas. Conclusions Extended follow-up of participants in prevention research is important to study the long-term effects of the interventions, such as those used in SELECT. The approach taken by SELECT investigators was to continue to follow participants centrally via an annual questionnaire and with a web-based option. The participants enrolled in the CFU study represent a large, well-characterized, generally healthy cohort. The CFU has enabled us to collect additional prostate and other cancer endpoints and longer follow-up on the almost 18,000 participants enrolled. The utility of the extensive biorepository that was developed during the course of the SELECT is enhanced by longer follow-up. PMID:23064404

Routine versus selective contrast imaging to identify the need for early re-intervention following laparoscopic fundoplication: A retrospective cohort study.

PubMed

Shahzad, Khalid; Menon, Ashok; Turner, Paul; Ward, Jeremy; Pursnani, Kishore; Alkhaffaf, Bilal

2015-08-01

The prompt recognition of complications is essential in reducing morbidity following anti-reflux surgery. Consequently, many centres employ a policy of routine post-operative contrast studies. The study aimed to examine whether routine contrast studies more effectively recognised early post-operative complications following anti-reflux surgery compared with selective use. This was a retrospective analysis of 240 adults who had undergone primary anti-reflux surgery. Selective use of water-soluble contrast swallows was employed for 115 patients (Group 1) while 125 patients (Group 2) had routine studies. 10 (0.9%) patients from Group 1 underwent contrast studies, four (40%) of which were abnormal. Routine studies in Group 2 identified thirty-two abnormalities (27%) however the inter-group difference was not significant (p = 0.32). Only one case from group 2 required immediate re-intervention. This was not statistically significant (p = 0.78). Multivariate analysis found no significant association between selective or routine imaging and re-intervention rates. One patient from group 2 presented three days following discharge with wrap migration requiring reoperation despite a normal post-operative study. Routine use of contrast imaging following anti-reflux and hiatus hernia surgery is not necessary. It does not identify a significantly greater number of post-operative complications in comparison to selective use. Additionally, routine use of contrast studies does not ensure the diagnosis of all complications in the post-operative period. Copyright © 2015 IJS Publishing Group Limited. Published by Elsevier Ltd. All rights reserved.

Testing the Effects of Peer Socialization versus Selection on Alcohol and Marijuana Use among Treated Adolescents

PubMed Central

Becker, Sara J.; Curry, John F.

2014-01-01

This study examined the relative influence of peer socialization and selection on alcohol and marijuana use among 106 adolescents who received a brief intervention. Adolescents were recruited between 2003 and 2007 and followed for 12 months as part of a SAMHSA-funded study. Cross-lagged panel models using four assessment points examined the longitudinal relationship between adolescent substance use and peer substance involvement separately for alcohol and marijuana. Consistent with community studies, there was evidence of both peer socialization and peer selection for alcohol use, and only evidence of peer selection for marijuana use. Implications for research and intervention are discussed. PMID:23965039

Selection process for trade study: Reusable Hydrogen Composite Tank System (RHCTS)

NASA Astrophysics Data System (ADS)

Greenberg, H. S.

1994-09-01

This document describes the selection process that will be used to identify the most suitable structural configuration option for an SSTO winged vehicle capable of delivering 25,000 lbs to a 220 nm circular orbit at 51.6 degree inclination. The most suitable RHCTS is within this configuration and will be the prototype design for subsequent design and analysis and the basis for the design and fabrication of a scale test article to be subjected to life cycle testing. The selection process for this TA 1 trade study is the same as that for the TA 2 trade study. As the trade study progresses additional insight may result in modifications to the selection criteria within in this process. Such modifications will result in an update of this document as appropriate.

Mixed conditional logistic regression for habitat selection studies.

PubMed

Duchesne, Thierry; Fortin, Daniel; Courbin, Nicolas

2010-05-01

1. Resource selection functions (RSFs) are becoming a dominant tool in habitat selection studies. RSF coefficients can be estimated with unconditional (standard) and conditional logistic regressions. While the advantage of mixed-effects models is recognized for standard logistic regression, mixed conditional logistic regression remains largely overlooked in ecological studies. 2. We demonstrate the significance of mixed conditional logistic regression for habitat selection studies. First, we use spatially explicit models to illustrate how mixed-effects RSFs can be useful in the presence of inter-individual heterogeneity in selection and when the assumption of independence from irrelevant alternatives (IIA) is violated. The IIA hypothesis states that the strength of preference for habitat type A over habitat type B does not depend on the other habitat types also available. Secondly, we demonstrate the significance of mixed-effects models to evaluate habitat selection of free-ranging bison Bison bison. 3. When movement rules were homogeneous among individuals and the IIA assumption was respected, fixed-effects RSFs adequately described habitat selection by simulated animals. In situations violating the inter-individual homogeneity and IIA assumptions, however, RSFs were best estimated with mixed-effects regressions, and fixed-effects models could even provide faulty conclusions. 4. Mixed-effects models indicate that bison did not select farmlands, but exhibited strong inter-individual variations in their response to farmlands. Less than half of the bison preferred farmlands over forests. Conversely, the fixed-effect model simply suggested an overall selection for farmlands. 5. Conditional logistic regression is recognized as a powerful approach to evaluate habitat selection when resource availability changes. This regression is increasingly used in ecological studies, but almost exclusively in the context of fixed-effects models. Fitness maximization can imply differences in trade-offs among individuals, which can yield inter-individual differences in selection and lead to departure from IIA. These situations are best modelled with mixed-effects models. Mixed-effects conditional logistic regression should become a valuable tool for ecological research.

Auditory selective attention in adolescents with major depression: An event-related potential study.

PubMed

Greimel, E; Trinkl, M; Bartling, J; Bakos, S; Grossheinrich, N; Schulte-Körne, G

2015-02-01

Major depression (MD) is associated with deficits in selective attention. Previous studies in adults with MD using event-related potentials (ERPs) reported abnormalities in the neurophysiological correlates of auditory selective attention. However, it is yet unclear whether these findings can be generalized to MD in adolescence. Thus, the aim of the present ERP study was to explore the neural mechanisms of auditory selective attention in adolescents with MD. 24 male and female unmedicated adolescents with MD and 21 control subjects were included in the study. ERPs were collected during an auditory oddball paradigm. Depressive adolescents tended to show a longer N100 latency to target and non-target tones. Moreover, MD subjects showed a prolonged latency of the P200 component to targets. Across groups, longer P200 latency was associated with a decreased tendency of disinhibited behavior as assessed by a behavioral questionnaire. To be able to draw more precise conclusions about differences between the neural bases of selective attention in adolescents vs. adults with MD, future studies should include both age groups and apply the same experimental setting across all subjects. The study provides strong support for abnormalities in the neurophysiolgical bases of selective attention in adolecents with MD at early stages of auditory information processing. Absent group differences in later ERP components reflecting voluntary attentional processes stand in contrast to results reported in adults with MD and may suggest that adolescents with MD possess mechanisms to compensate for abnormalities in the early stages of selective attention. Copyright © 2014 Elsevier B.V. All rights reserved.

Space Use and Habitat Selection by Resident and Transient Coyotes (Canis latrans)

PubMed Central

Hinton, Joseph W.; van Manen, Frank T.; Chamberlain, Michael J.

2015-01-01

Little information exists on coyote (Canis latrans) space use and habitat selection in the southeastern United States and most studies conducted in the Southeast have been carried out within small study areas (e.g., ≤1,000 km2). Therefore, studying the placement, size, and habitat composition of coyote home ranges over broad geographic areas could provide relevant insights regarding how coyote populations adjust to regionally varying ecological conditions. Despite an increasing number of studies of coyote ecology, few studies have assessed the role of transiency as a life-history strategy among coyotes. During 2009–2011, we used GPS radio-telemetry to study coyote space use and habitat selection on the Albemarle Peninsula of northeastern North Carolina. We quantified space use and 2nd- and 3rd-order habitat selection for resident and transient coyotes to describe space use patterns in a predominantly agricultural landscape. The upper limit of coyote home-range size was approximately 47 km2 and coyotes exhibiting shifting patterns of space use of areas >65 km2 were transients. Transients exhibited localized space use patterns for short durations prior to establishing home ranges, which we defined as “biding” areas. Resident and transient coyotes demonstrated similar habitat selection, notably selection of agricultural over forested habitats. However, transients exhibited stronger selection for roads than resident coyotes. Although transient coyotes are less likely to contribute reproductively to their population, transiency may be an important life history trait that facilitates metapopulation dynamics through dispersal and the eventual replacement of breeding residents lost to mortality. PMID:26148130

Space use and habitat selection by resident and transient coyotes (Canis latrans)

USGS Publications Warehouse

Hinton, Joseph W; van Manen, Frank T.; Chamberlain, Michael J

2015-01-01

Little information exists on coyote (Canis latrans) space use and habitat selection in the southeastern United States and most studies conducted in the Southeast have been carried out within small study areas (e.g., ≤1,000 km2). Therefore, studying the placement, size, and habitat composition of coyote home ranges over broad geographic areas could provide relevant insights regarding how coyote populations adjust to regionally varying ecological conditions. Despite an increasing number of studies of coyote ecology, few studies have assessed the role of transiency as a life-history strategy among coyotes. During 2009–2011, we used GPS radio-telemetry to study coyote space use and habitat selection on the Albemarle Peninsula of northeastern North Carolina. We quantified space use and 2nd- and 3rd-order habitat selection for resident and transient coyotes to describe space use patterns in a predominantly agricultural landscape. The upper limit of coyote home-range size was approximately 47 km2 and coyotes exhibiting shifting patterns of space use of areas >65 km2 were transients. Transients exhibited localized space use patterns for short durations prior to establishing home ranges, which we defined as “biding” areas. Resident and transient coyotes demonstrated similar habitat selection, notably selection of agricultural over forested habitats. However, transients exhibited stronger selection for roads than resident coyotes. Although transient coyotes are less likely to contribute reproductively to their population, transiency may be an important life history trait that facilitates metapopulation dynamics through dispersal and the eventual replacement of breeding residents lost to mortality.

The search for loci under selection: trends, biases and progress.

PubMed

Ahrens, Collin W; Rymer, Paul D; Stow, Adam; Bragg, Jason; Dillon, Shannon; Umbers, Kate D L; Dudaniec, Rachael Y

2018-03-01

Detecting genetic variants under selection using F ST outlier analysis (OA) and environmental association analyses (EAAs) are popular approaches that provide insight into the genetic basis of local adaptation. Despite the frequent use of OA and EAA approaches and their increasing attractiveness for detecting signatures of selection, their application to field-based empirical data have not been synthesized. Here, we review 66 empirical studies that use Single Nucleotide Polymorphisms (SNPs) in OA and EAA. We report trends and biases across biological systems, sequencing methods, approaches, parameters, environmental variables and their influence on detecting signatures of selection. We found striking variability in both the use and reporting of environmental data and statistical parameters. For example, linkage disequilibrium among SNPs and numbers of unique SNP associations identified with EAA were rarely reported. The proportion of putatively adaptive SNPs detected varied widely among studies, and decreased with the number of SNPs analysed. We found that genomic sampling effort had a greater impact than biological sampling effort on the proportion of identified SNPs under selection. OA identified a higher proportion of outliers when more individuals were sampled, but this was not the case for EAA. To facilitate repeatability, interpretation and synthesis of studies detecting selection, we recommend that future studies consistently report geographical coordinates, environmental data, model parameters, linkage disequilibrium, and measures of genetic structure. Identifying standards for how OA and EAA studies are designed and reported will aid future transparency and comparability of SNP-based selection studies and help to progress landscape and evolutionary genomics. © 2018 John Wiley & Sons Ltd.

Mobile Eye Tracking Reveals Little Evidence for Age Differences in Attentional Selection for Mood Regulation

PubMed Central

Isaacowitz, Derek M.; Livingstone, Kimberly M.; Harris, Julia A.; Marcotte, Stacy L.

2014-01-01

We report two studies representing the first use of mobile eye tracking to study emotion regulation across adulthood. Past research on age differences in attentional deployment using stationary eye tracking has found older adults show relatively more positive looking, and seem to benefit more mood-wise from this looking pattern, compared to younger adults. However, these past studies have greatly constrained the stimuli participants can look at, despite real-world settings providing numerous possibilities for what to choose to look at. We therefore used mobile eye tracking to study age differences in attentional selection, as indicated by fixation patterns to stimuli of different valence freely chosen by the participant. In contrast to stationary eye tracking studies of attentional deployment, Study 1 showed that younger and older individuals generally selected similar proportions of valenced stimuli, and attentional selection had similar effects on mood across age groups. Study 2 replicated this pattern with an adult lifespan sample including middle-aged individuals. Emotion regulation-relevant attention may thus differ depending on whether stimuli are freely chosen or not. PMID:25527965

Social Studies: Selected Cultures. Grade 6.

ERIC Educational Resources Information Center

Taylor, Marshall R.

This revised teachers guide attempts to facilitate the study of selected cultures through a conceptual approach and multimedia instruction in a spiral curriculum. There are six units: 1) Cultures and Archaeology --cultural factors, cultural study, artifacts, fossils, archaeological sites and evidence; 2) Food Gathering Complex --life styles,…

Supply of and demand for selected energy related mineral commodities

USGS Publications Warehouse

Sibley, Scott F.

2010-01-01

In this report, subjects discussed include components of mineral supply, production, and consumption data, and information on selected mineral commodities in which the Energy Critical Elements Study Group has an interest, and U.S. Geological Survey (USGS) recycling studies, with some results of these studies.

Configuration development study of the X-24C hypersonic research airplane, phase 2

NASA Technical Reports Server (NTRS)

Combs, H. G.

1977-01-01

The X-24C Hypersonic Research Vehicle, configured with a heat-sink structure, a launch mass limit of 31.75 Mg and powered by an LR-105 Rocket Engine plus 12 LR-101 Sustainer Engines, was found to be the more cost effective of the candidate configurations. In addition, the configuration provides the maximum off design growth potential capability and subsequently, was selected as the candidate configuration to be subjected to the design refinement study in the remaining segment of the study. Selection of this configuration was based on the analytical study conducted on the performance growth capabilities of the candidate configurations selected from the Phase 1 Study.

The predictive validity of a situational judgement test, a clinical problem solving test and the core medical training selection methods for performance in specialty training .

PubMed

Patterson, Fiona; Lopes, Safiatu; Harding, Stephen; Vaux, Emma; Berkin, Liz; Black, David

2017-02-01

The aim of this study was to follow up a sample of physicians who began core medical training (CMT) in 2009. This paper examines the long-term validity of CMT and GP selection methods in predicting performance in the Membership of Royal College of Physicians (MRCP(UK)) examinations. We performed a longitudinal study, examining the extent to which the GP and CMT selection methods (T1) predict performance in the MRCP(UK) examinations (T2). A total of 2,569 applicants from 2008-09 who completed CMT and GP selection methods were included in the study. Looking at MRCP(UK) part 1, part 2 written and PACES scores, both CMT and GP selection methods show evidence of predictive validity for the outcome variables, and hierarchical regressions show the GP methods add significant value to the CMT selection process. CMT selection methods predict performance in important outcomes and have good evidence of validity; the GP methods may have an additional role alongside the CMT selection methods. © Royal College of Physicians 2017. All rights reserved.

A family longevity selection score: ranking sibships by their longevity, size, and availability for study.

PubMed

Sebastiani, Paola; Hadley, Evan C; Province, Michael; Christensen, Kaare; Rossi, Winifred; Perls, Thomas T; Ash, Arlene S

2009-12-15

Family studies of exceptional longevity can potentially identify genetic and other factors contributing to long life and healthy aging. Although such studies seek families that are exceptionally long lived, they also need living members who can provide DNA and phenotype information. On the basis of these considerations, the authors developed a metric to rank families for selection into a family study of longevity. Their measure, the family longevity selection score (FLoSS), is the sum of 2 components: 1) an estimated family longevity score built from birth-, gender-, and nation-specific cohort survival probabilities and 2) a bonus for older living siblings. The authors examined properties of FLoSS-based family rankings by using data from 3 ongoing studies: the New England Centenarian Study, the Framingham Heart Study, and screenees for the Long Life Family Study. FLoSS-based selection yields families with exceptional longevity, satisfactory sibship sizes and numbers of living siblings, and high ages. Parameters in the FLoSS formula can be tailored for studies of specific populations or age ranges or with different conditions. The first component of the FLoSS also provides a conceptually sound survival measure to characterize exceptional longevity in individuals or families in various types of studies and correlates well with later-observed longevity.

Performance of the disease risk score in a cohort study with policy-induced selection bias.

PubMed

Tadrous, Mina; Mamdani, Muhammad M; Juurlink, David N; Krahn, Murray D; Lévesque, Linda E; Cadarette, Suzanne M

2015-11-01

To examine the performance of the disease risk score (DRS) in a cohort study with evidence of policy-induced selection bias. We examined two cohorts of new users of bisphosphonates. Estimates for 1-year hip fracture rates between agents using DRS, exposure propensity scores and traditional multivariable analysis were compared. The results for the cohort with no evidence of policy-induced selection bias showed little variation across analyses (-4.1-2.0%). Analysis of the cohort with evidence of policy-induced selection bias showed greater variation (-13.5-8.1%), with the greatest difference seen with DRS analyses. Our findings suggest that caution may be warranted when using DRS methods in cohort studies with policy-induced selection bias, further research is needed.

Improving the Textbook Selection Process: Case Studies of the Textbook Adoption Guidelines Project. Technical Report No. 478.

ERIC Educational Resources Information Center

Dole, Janice; And Others

A study followed three textbook adoption committees as they evaluated basal reading programs. The committees used "A Guide to Selecting Basal Reading Programs" (developed at the Center for the Study of Reading) to help them evaluate the quality of instruction in existing programs. Case studies of the three committees sought to address the…

A Critical Case Study of Selected United States History Textbooks from a Tribal Critical Race Theory Perspective

ERIC Educational Resources Information Center

Padgett, Gary

2012-01-01

The purpose of this study was to describe and explain the portrayal of American Indians in U.S. textbooks selected for review in Hillsborough County, Florida's 2012 textbook adoption. The study identified which of the textbooks under consideration contained the greatest amount of information dedicated to American Indians. The study then analyzed…

Utilization of Selected Vitality Staple Foods by Low Income Households in Ebonyi State

ERIC Educational Resources Information Center

Igba, Chimezie Elizabeth; Okoro, M. O.

2015-01-01

The study focused on the utilization of selected vitality foods among low income household in Ebonyi State. Specifically the study aimed at identifying vitality foods that are available, accessible and utilized by low income household in state. Descriptive survey design was used for the study. The population of the study is 2,173,501 households…

Strategies used for the promotion of critical thinking in nursing undergraduate education: A systematic review.

PubMed

Carvalho, Diana P S R P; Azevedo, Isabelle C; Cruz, Giovanna K P; Mafra, Gabriela A C; Rego, Anna L C; Vitor, Allyne F; Santos, Viviane E P; Cogo, Ana L P; Ferreira Júnior, Marcos A

2017-10-01

Identifying the strategies used to promote critical thinking (CT) during undergraduate education in nursing courses. Systematic review. Five electronic databases were searched without language, publication time or geographic filters. A systematic review of the literature. Including experimental studies that considered at least one teaching strategy to promote critical thinking of undergraduate students in Nursing courses. The search for studies occurred in three phases: title and summary review, complete text and implementation of a clinical form of selection according to predetermined criteria. All included studies were assessed for quality through a classification tool for experimental studies. Six studies were selected. The results were grouped into three key themes: an evaluation of the quality of the selected studies, characterization of the studies and the strategies used to promote critical thinking. All selected studies were in English, with significant conceptual similarity of Critical Thinking and dominance in choosing the approached theme during strategies in clinical nursing education with an emphasis on the nursing process. The most widely used teaching intervention was Problem-Based Learning. Nursing education mediated by strategies that stimulate CT is considered a positive difference in undergraduate curriculums. Copyright © 2017 Elsevier Ltd. All rights reserved.

Distributed Leadership in Elementary Schools: An Exploratory Multiple Case Study

ERIC Educational Resources Information Center

Valdez, Vidal

2016-01-01

The purpose of this study was to explore distributed leadership and how leadership practices are actualized in three selected schools in Southern California. This qualitative, multiple case study used survey research and interviews to assess how distributed leadership was practiced in three selected elementary schools located within one school…

Authenticating Historical Fiction: Rationale and Process

ERIC Educational Resources Information Center

Groce, Eric; Groce, Robin

2005-01-01

In merging social studies education with language arts, classroom teachers are utilizing selections of historical fiction to teach critical literacy skills while also meeting social studies standards. While most of the selections used for teaching history and social studies themes are strong in terms of literary merit, they may be deficient in…

77 FR 23263 - Proposed Data Collections Submitted for Public Comment and Recommendations

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-18

... days of this notice. Proposed Project Targeted Surveillance and Biometric Studies for Enhanced... outcome data collection in select communities. The initial selected studies will address biometric changes... health impact. CDC is requesting OMB approval to conduct the Youth and Adult Biometric Study (YABS), one...

Methods Used in a Recent Computer Selection Study.

ERIC Educational Resources Information Center

Botten, LeRoy H.

A study was conducted at Andrews University, Berrien Springs, Michigan to determine selection of a computer for both academic and administrative purposes. The university has a total enrollment of 2,100 students and includes a college, graduate school and seminary. An initial feasibility study delineated criteria and desirable components of the…

Medical Tourist's Perception in Selecting their Destination: A Global Perspective.

PubMed

Sarwar, Abdullah Am; Manaf, Noorhazilah A; Omar, Azura

2012-01-01

The need for better healthcare has grown significantly in recent years. In addition, the rising healthcare costs in the U.S. and in many European countries have forced many patients to seek medical treatment abroad, which has created the demand for medical tourism. With little yet known as to the perception of a medical tourist's destination selection, this study aims to explore medical tourist's perception in selecting their destination while going for medical treatment. Realizing the current need to examine closely the perception of medical tourists, this study had conducted a secondary study to collect data for assessing and identification of the key factors on patient's perception and destination selection criteria. The result confirms the existence of a very strong relationship between cost, service quality, treatment types and availability and marketing impact on the perception of the medical tourists' in selecting their medical tourism destination. This study offers support for the proposed conceptual model and an empirical basis for comparison in future research.

Upper limb dysfunction following selective neck dissection: a retrospective questionnaire study.

PubMed

Carr, Simon D; Bowyer, Duncan; Cox, Graham

2009-06-01

To determine total upper limb function following selective neck dissection over a mean follow-up of 1.6 years. A retrospective questionnaire study in a tertiary head and neck surgical unit. One hundred forty-eight patients who underwent selective neck dissection for head and neck cancer from January 2000 to December 2005 were invited to participate. The main outcome measure was ipsilateral upper limb dysfunction as measured by the Disability of Arm, Shoulder and Hand (DASH) questionnaire. Sixty-five patients responded to the invitation to join the study from 148 invited. Despite accessory nerve conserving surgery for all the selective neck dissections studied, 23% reported no upper limb dysfunction, 54% reported mild upper limb dysfunction, 15% reported moderate, and 8% reported a severe dysfunction. Long-term upper limb dysfunction is common following nerve preserving surgery. The DASH questionnaire is a useful preoperative and postoperative clinical tool for those patients undergoing selective neck dissections. (c) 2009 Wiley Periodicals, Inc.

Landfill site selection using combination of GIS and fuzzy AHP, a case study: Iranshahr, Iran.

PubMed

Torabi-Kaveh, M; Babazadeh, R; Mohammadi, S D; Zaresefat, M

2016-03-09

One of the most important recent challenges in solid waste management throughout the world is site selection of sanitary landfill. Commonly, because of simultaneous effects of social, environmental, and technical parameters on suitability of a landfill site, landfill site selection is a complex process and depends on several criteria and regulations. This study develops a multi-criteria decision analysis (MCDA) process, which combines geographic information system (GIS) analysis with a fuzzy analytical hierarchy process (FAHP), to determine suitable sites for landfill construction in Iranshahr County, Iran. The GIS was used to calculate and classify selected criteria and FAHP was used to assess the criteria weights based on their effectiveness on selection of potential landfill sites. Finally, a suitability map was prepared by overlay analyses and suitable areas were identified. Four suitability classes within the study area were separated, including high, medium, low, and very low suitability areas, which represented 18%, 15%, 55%, and 12% of the study area, respectively. © The Author(s) 2016.

Medical Tourist’s Perception in Selecting their Destination: A Global Perspective

PubMed Central

Sarwar, Abdullah AM; Manaf, Noorhazilah A; Omar, Azura

2012-01-01

Background: The need for better healthcare has grown significantly in recent years. In addition, the rising healthcare costs in the U.S. and in many European countries have forced many patients to seek medical treatment abroad, which has created the demand for medical tourism. With little yet known as to the perception of a medical tourist’s destination selection, this study aims to explore medical tourist’s perception in selecting their destination while going for medical treatment. Methods: Realizing the current need to examine closely the perception of medical tourists, this study had conducted a secondary study to collect data for assessing and identification of the key factors on patient’s perception and destination selection criteria. Results: The result confirms the existence of a very strong relationship between cost, service quality, treatment types and availability and marketing impact on the perception of the medical tourists’ in selecting their medical tourism destination. Conclusion: This study offers support for the proposed conceptual model and an empirical basis for comparison in future research. PMID:23113218

Globalization in Education Counts: A Comparative Study of Selected International School Associations and Selected Charter High Schools

ERIC Educational Resources Information Center

Johnson-Dunn, Tina N.

2009-01-01

The purpose of this study was to identify, examine, and compare the way globalization was perceived by 4 international school associations, 4 non-profit (corporate managed) charter high schools, and 4 independent (individually managed) charter high schools from Southern California. Selected school associations, non-profit, and independent charter…

Treating Selective Mutism Using Modular CBT for Child Anxiety: A Case Study

ERIC Educational Resources Information Center

Reuther, Erin T.; Davis, Thompson E., III; Moree, Brittany N.; Matson, Johnny L.

2011-01-01

Selective mutism is a rare, debilitating condition usually seen in children. Unfortunately, there is little research examining effective treatments for this disorder, and designing an evidence-based treatment plan can be difficult. This case study presents the evidence-based treatment of an 8-year-old Caucasian boy with selective mutism using an…

The Empirical Selection of Anchor Items Using a Multistage Approach

ERIC Educational Resources Information Center

Craig, Brandon

2017-01-01

The purpose of this study was to determine if using a multistage approach for the empirical selection of anchor items would lead to more accurate DIF detection rates than the anchor selection methods proposed by Kopf, Zeileis, & Strobl (2015b). A simulation study was conducted in which the sample size, percentage of DIF, and balance of DIF…

Selection of roosting habitat by forest bats in a diverse forested landscape

Treesearch

Roger W. Perry; Ronald E. Thill; David M. Leslie

2007-01-01

Many studies of roost selection by forest-dwelling bats have concentrated on microhabitat surrounding roosts without providing forest stand level preferences of bats; thus, those studies have provided only part of the information needed by managers. We evaluated diurnal summer roost selection by the bat community at the forest-stand level in a diversely forested...

Kinetic Studies with Ion Selective Electrodes: Determination of Creatinine in Urine with a Picrate Ion Selective Electrode: A Laboratory Experiment.

ERIC Educational Resources Information Center

Diamandis, E. P.; And Others

1983-01-01

The kinetic of the Jaffe reaction with picrate ion selective electrode (ISE) and a kinetic method for determining creatinine in urine is presented. The experiment could be used to familarize students with the application of ISE in kinetic studies and chemical analysis. (Author/JN)

Evolutionary Theory of Mate Selection and Partners of Trans People: A Qualitative Study Using Interpretative Phenomenological Analysis

ERIC Educational Resources Information Center

Forde, Amanda

2011-01-01

Despite much research into mate selection, non-heterosexual populations are often only included for comparison purposes, while trans people and their partners are overlooked. This study attempts to address this using qualitative methodology to explore the mate selection of the partners of trans people. Six participants were recruited from online…

Using step and path selection functions for estimating resistance to movement: Pumas as a case study

Treesearch

Katherine A. Zeller; Kevin McGarigal; Samuel A. Cushman; Paul Beier; T. Winston Vickers; Walter M. Boyce

2015-01-01

GPS telemetry collars and their ability to acquire accurate and consistently frequent locations have increased the use of step selection functions (SSFs) and path selection functions (PathSFs) for studying animal movement and estimating resistance. However, previously published SSFs and PathSFs often do not accommodate multiple scales or multiscale modeling....

Mechanisms of Reference Frame Selection in Spatial Term Use: Computational and Empirical Studies

ERIC Educational Resources Information Center

Schultheis, Holger; Carlson, Laura A.

2017-01-01

Previous studies have shown that multiple reference frames are available and compete for selection during the use of spatial terms such as "above." However, the mechanisms that underlie the selection process are poorly understood. In the current paper we present two experiments and a comparison of three computational models of selection…

Latino College Students at Highly Selective Institutions: A Comparison of Their College Experiences and Outcomes to Other Racial/Ethnic Groups

ERIC Educational Resources Information Center

Kim, Young K.; Rennick, Liz A.; Franco, Marla A.

2014-01-01

This study examines unique patterns of college engagement and outcomes among Latino undergraduate students attending highly selective institutions in comparison with those from other racial/ethnic groups. The study also identifies predictors of select college outcomes--that is, cognitive, affective, and civic outcomes--for this population.…

Selection into Medicine Using Interviews and Other Measures: Much Remains to Be Learned

ERIC Educational Resources Information Center

Ma, Colleen; Harris, Peter; Cole, Andrew; Jones, Phil; Shulruf, Boaz

2016-01-01

The objectives of this study were to identify the effectiveness of the panel admission interview as a selection tool for the medical program and identify improvements in the selection tools battery. Data from 1024 students, representing four cohorts of students were used in this study. Exploratory factor analysis using principal component analysis…

Selection of Educational Materials in the United States Public Schools.

ERIC Educational Resources Information Center

Institute for Educational Development, New York, NY.

The objective of this study was to collect "baseline" data with which to examine a complex process in the educational system--the selection of educational materials. The first part of the study analyzes the statutes of the fifty states which bear upon selection and purchase of educational materials. The purpose of this analysis is to…

Neural and cognitive face-selective markers: An integrative review.

PubMed

Yovel, Galit

2016-03-01

Faces elicit robust and selective neural responses in the primate brain. These neural responses have been investigated with functional MRI and EEG in numerous studies, which have reported face-selective activations in the occipital-temporal cortex and an electrophysiological face-selective response that peaks 170 ms after stimulus onset at occipital-temporal sites. Evidence for face-selective processes has also been consistently reported in cognitive studies, which investigated the face inversion effect, the composite face effect and the left visual field (LVF) superiority. These cognitive effects indicate that the perceptual representation that we generate for faces differs from the representation that is generated for inverted faces or non-face objects. In this review, I will show that the fMRI and ERP face-selective responses are strongly associated with these three well-established behavioral face-selective measures. I will further review studies that examined the relationship between fMRI and EEG face-selective measures suggesting that they are strongly linked. Taken together these studies imply that a holistic representation of a face is generated at 170 ms after stimulus onset over the right hemisphere. These findings, which reveal a strong link between the various and complementary cognitive and neural measures of face processing, allow to characterize where, when and how faces are represented during the first 200 ms of face processing. Copyright © 2015 Elsevier Ltd. All rights reserved.

Habitat Selection and Risk of Predation: Re-colonization by Lynx had Limited Impact on Habitat Selection by Roe Deer

PubMed Central

Samelius, Gustaf; Andrén, Henrik; Kjellander, Petter; Liberg, Olof

2013-01-01

Risk of predation is an evolutionary force that affects behaviors of virtually all animals. In this study, we examined how habitat selection by roe deer was affected by risk of predation by Eurasian lynx – the main predator of roe deer in Scandinavia. Specifically, we compared how habitat selection by roe deer varied (1) before and after lynx re-established in the study area and (2) in relation to habitat-specific risk of predation by lynx. All analyses were conducted at the spatial and temporal scales of home ranges and seasons. We did not find any evidence that roe deer avoided habitats in which the risk of predation by lynx was greatest and information-theoretic model selection showed that re-colonization by lynx had limited impact on habitat selection by roe deer despite lynx predation causing 65% of known mortalities after lynx re-colonized the area. Instead we found that habitat selection decreased when habitat availability increased for 2 of 5 habitat types (a pattern referred to as functional response in habitat selection). Limited impact of re-colonization by lynx on habitat selection by roe deer in this study differs from elk in North America altering both daily and seasonal patterns in habitat selection at the spatial scales of habitat patches and home ranges when wolves were reintroduced to Yellowstone National Park. Our study thus provides further evidence of the complexity by which animals respond to risk of predation and suggest that it may vary between ecosystems and predator-prey constellations. PMID:24069419

Habitat selection and risk of predation: re-colonization by lynx had limited impact on habitat selection by roe deer.

PubMed

Samelius, Gustaf; Andrén, Henrik; Kjellander, Petter; Liberg, Olof

2013-01-01

Risk of predation is an evolutionary force that affects behaviors of virtually all animals. In this study, we examined how habitat selection by roe deer was affected by risk of predation by Eurasian lynx - the main predator of roe deer in Scandinavia. Specifically, we compared how habitat selection by roe deer varied (1) before and after lynx re-established in the study area and (2) in relation to habitat-specific risk of predation by lynx. All analyses were conducted at the spatial and temporal scales of home ranges and seasons. We did not find any evidence that roe deer avoided habitats in which the risk of predation by lynx was greatest and information-theoretic model selection showed that re-colonization by lynx had limited impact on habitat selection by roe deer despite lynx predation causing 65% of known mortalities after lynx re-colonized the area. Instead we found that habitat selection decreased when habitat availability increased for 2 of 5 habitat types (a pattern referred to as functional response in habitat selection). Limited impact of re-colonization by lynx on habitat selection by roe deer in this study differs from elk in North America altering both daily and seasonal patterns in habitat selection at the spatial scales of habitat patches and home ranges when wolves were reintroduced to Yellowstone National Park. Our study thus provides further evidence of the complexity by which animals respond to risk of predation and suggest that it may vary between ecosystems and predator-prey constellations.

All-cause mortality of elderly Australian veterans using COX-2 selective or non-selective NSAIDs: a longitudinal study

PubMed Central

Kerr, Stephen J; Rowett, Debra S; Sayer, Geoffrey P; Whicker, Susan D; Saltman, Deborah C; Mant, Andrea

2011-01-01

AIM To determine hazard ratios for all-cause mortality in elderly Australian veterans taking COX-2 selective and non-selective NSAIDs. METHODS Patient cohorts were constructed from claims databases (1997 to 2007) for veterans and dependants with full treatment entitlement irrespective of military service. Patients were grouped by initial exposure: celecoxib, rofecoxib, meloxicam, diclofenac, non-selective NSAID. A reference group was constructed of patients receiving glaucoma/hypothyroid medications and none of the study medications. Univariate and multivariate analyses were performed using Cox proportional hazards regression models. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated for each exposure group against each of the reference group. The final model was adjusted for age, gender and co-prescription as a surrogate for cardiovascular risk. Patients were censored if the gap in supply of study prescription exceeded 30 days or if another study medication was initiated. The outcome measure in all analyses was death. RESULTS Hazard ratios and 95% CIs, adjusted for age, gender and cardiovascular risk, for each group relative to the reference group were: celecoxib 1.39 (1.25, 1.55), diclofenac 1.44 (1.28, 1.62), meloxicam 1.49 (1.25, 1.78), rofecoxib 1.58 (1.39, 1.79), non-selective NSAIDs 1.76 (1.59, 1.94). CONCLUSIONS In this large cohort of Australian veterans exposed to COX-2 selective and non-selective NSAIDs, there was a significant increased mortality risk for those exposed to either COX-2-selective or non-selective NSAIDs relative to those exposed to unrelated (glaucoma/hypothyroid) medications. PMID:21276041

Selection Practices of Group Leaders: A National Survey.

ERIC Educational Resources Information Center

Riva, Maria T.; Lippert, Laurel; Tackett, M. Jan

2000-01-01

Study surveys the selection practices of group leaders. Explores methods of selection, variables used to make selection decisions, and the types of selection errors that leaders have experienced. Results suggest that group leaders use clinical judgment to make selection decisions and endorse using some specific variables in selection. (Contains 22…

Revealing the selection history of adaptive loci using genome-wide scans for selection: an example from domestic sheep.

PubMed

Rochus, Christina Marie; Tortereau, Flavie; Plisson-Petit, Florence; Restoux, Gwendal; Moreno-Romieux, Carole; Tosser-Klopp, Gwenola; Servin, Bertrand

2018-01-23

One of the approaches to detect genetics variants affecting fitness traits is to identify their surrounding genomic signatures of past selection. With established methods for detecting selection signatures and the current and future availability of large datasets, such studies should have the power to not only detect these signatures but also to infer their selective histories. Domesticated animals offer a powerful model for these approaches as they adapted rapidly to environmental and human-mediated constraints in a relatively short time. We investigated this question by studying a large dataset of 542 individuals from 27 domestic sheep populations raised in France, genotyped for more than 500,000 SNPs. Population structure analysis revealed that this set of populations harbour a large part of European sheep diversity in a small geographical area, offering a powerful model for the study of adaptation. Identification of extreme SNP and haplotype frequency differences between populations listed 126 genomic regions likely affected by selection. These signatures revealed selection at loci commonly identified as selection targets in many species ("selection hotspots") including ABCG2, LCORL/NCAPG, MSTN, and coat colour genes such as ASIP, MC1R, MITF, and TYRP1. For one of these regions (ABCG2, LCORL/NCAPG), we could propose a historical scenario leading to the introgression of an adaptive allele into a new genetic background. Among selection signatures, we found clear evidence for parallel selection events in different genetic backgrounds, most likely for different mutations. We confirmed this allelic heterogeneity in one case by resequencing the MC1R gene in three black-faced breeds. Our study illustrates how dense genetic data in multiple populations allows the deciphering of evolutionary history of populations and of their adaptive mutations.

Selection bias and patterns of confounding in cohort studies: the case of the NINFEA web-based birth cohort.

PubMed

Pizzi, Costanza; De Stavola, Bianca L; Pearce, Neil; Lazzarato, Fulvio; Ghiotti, Paola; Merletti, Franco; Richiardi, Lorenzo

2012-11-01

Several studies have examined the effects of sample selection on the exposure-outcome association estimates in cohort studies, but the reasons why this selection may induce bias have not been fully explored. To investigate how sample selection of the web-based NINFEA birth cohort may change the confounding patterns present in the source population. The characteristics of the NINFEA participants (n=1105) were compared with those of the wider source population-the Piedmont Birth Registry (PBR)-(n=36 092), and the association of two exposures (parity and educational level) with two outcomes (low birth weight and birth by caesarean section), while controlling for other risk factors, was studied. Specifically the associations among measured risk factors within each dataset were examined and the exposure-outcome estimates compared in terms of relative ORs. The associations of educational level with the other risk factors (alcohol consumption, folic acid intake, maternal age, pregnancy weight gain, previous miscarriages) partly differed between PBR and NINFEA. This was not observed for parity. Overall, the exposure-outcome estimates derived from NINFEA only differed moderately from those obtained in PBR, with relative ORs ranging between 0.74 and 1.03. Sample selection in cohort studies may alter the confounding patterns originally present in the general population. However, this does not necessarily introduce selection bias in the exposure-outcome estimates, as sample selection may reduce some of the residual confounding present in the general population.

Using phenotypic manipulations to study multivariate selection of floral trait associations.

PubMed

Campbell, Diane R

2009-06-01

A basic theme in the study of plant-pollinator interactions is that pollinators select not just for single floral traits, but for associations of traits. Responses of pollinators to sets of traits are inherent in the idea of pollinator syndromes. In its most extreme form, selection on a suite of traits can take the form of correlational selection, in which a response to one trait depends on the value of another, thereby favouring floral integration. Despite the importance of selection for combinations of traits in the evolution of flowers, evidence is relatively sparse and relies mostly on observational approaches. Here, methods for measuring selection on multivariate suites of floral traits are presented, and the studies to date are reviewed. It is argued that phenotypic manipulations present a powerful, but rarely used, approach to teasing apart the separate and combined effects of particular traits. The approach is illustrated with data from studies of alpine plants in Colorado and New Zealand, and recommendations are made about several features of the design of such experiments. Phenotypic manipulations of two or more traits in combination provide a direct way of testing for selection of floral trait associations. Such experiments will be particularly valuable if rooted in hypotheses about differences between types of pollinators and tied to a proposed evolutionary history.

Natural selection on immune defense: A field experiment.

PubMed

Langeloh, Laura; Behrmann-Godel, Jasminca; Seppälä, Otto

2017-02-01

Predicting the evolution of phenotypic traits requires an understanding of natural selection on them. Despite its indispensability in the fight against parasites, selection on host immune defense has remained understudied. Theory predicts immune traits to be under stabilizing selection due to associated trade-offs with other fitness-related traits. Empirical studies, however, report mainly positive directional selection. This discrepancy could be caused by low phenotypic variation in the examined individuals and/or variation in host resource level that confounds trade-offs in empirical studies. In a field experiment where we maintained Lymnaea stagnalis snails individually in cages in a lake, we investigated phenotypic selection on two immune defense traits, phenoloxidase (PO)-like activity and antibacterial activity, in hemolymph. We used a diverse laboratory population and manipulated snail resource level by limiting their food supply. For six weeks, we followed immune activity, growth, and two fitness components, survival and fecundity of snails. We found that PO-like activity and growth were under stabilizing selection, while antibacterial activity was under positive directional selection. Selection on immune traits was mainly driven by variation in survival. The form of selection on immune defense apparently depends on the particular trait, possibly due to its importance for countering the present parasite community. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

Separating selection by diurnal and nocturnal pollinators on floral display and spur length in Gymnadenia conopsea.

PubMed

Sletvold, Nina; Trunschke, Judith; Wimmergren, Carolina; Agren, Jon

2012-08-01

Most plants attract multiple flower visitors that may vary widely in their effectiveness as pollinators. Floral evolution is expected to reflect interactions with the most important pollinators, but few studies have quantified the contribution of different pollinators to current selection on floral traits. To compare selection mediated by diurnal and nocturnal pollinators on floral display and spur length in the rewarding orchid Gymnadenia conopsea, we manipulated the environment by conducting supplemental hand-pollinations and selective pollinator exclusions in two populations in central Norway. In both populations, the exclusion of diurnal pollinators significantly reduced seed production compared to open pollination, whereas the exclusion of nocturnal pollinators did not. There was significant selection on traits expected to influence pollinator attraction and pollination efficiency in both the diurnal and nocturnal pollination treatment. The relative strength of selection among plants exposed to diurnal and nocturnal visitors varied among traits and populations, but the direction of selection was consistent. The results suggest that diurnal pollinators are more important than nocturnal pollinators for seed production in the study populations, but that both categories contribute to selection on floral morphology. The study illustrates how experimental manipulations can link specific categories of pollinators to observed selection on floral traits, and thus improve our understanding of how species interactions shape patterns of selection.

Contribution of the pre-SMA to the production of words and non-speech oral motor gestures, as revealed by repetitive transcranial magnetic stimulation (rTMS).

PubMed

Tremblay, Pascale; Gracco, Vincent L

2009-05-01

An emerging theoretical perspective, largely based on neuroimaging studies, suggests that the pre-SMA is involved in planning cognitive aspects of motor behavior and language, such as linguistic and non-linguistic response selection. Neuroimaging studies, however, cannot indicate whether a brain region is equally important to all tasks in which it is activated. In the present study, we tested the hypothesis that the pre-SMA is an important component of response selection, using an interference technique. High frequency repetitive TMS (10 Hz) was used to interfere with the functioning of the pre-SMA during tasks requiring selection of words and oral gestures under different selection modes (forced, volitional) and attention levels (high attention, low attention). Results show that TMS applied to the pre-SMA interferes selectively with the volitional selection condition, resulting in longer RTs. The low- and high-attention forced selection conditions were unaffected by TMS, demonstrating that the pre-SMA is sensitive to selection mode but not attentional demands. TMS similarly affected the volitional selection of words and oral gestures, reflecting the response-independent nature of the pre-SMA contribution to response selection. The implications of these results are discussed.

Transient studies of low temperature catalysts for methane conversion. Final report, [September 1992--March 1996

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

Wolf, E.E.

1996-09-30

The objective of this project is to use transient techniques to study gas surface interactions during the oxidative conversion of methane. Two groups of catalysts were studied: a double oxide of vanadium and phosphate or VPO, and double oxides of Ni, Co and Rh and lanthana. The objective of the studies involving the VPO catalyst was to understand gas-surface interactions leading to the formation of formaldehyde. In the second group of catalysts, involving metallo-oxides, the main objective was to study the gas-surface interactions that determine the selectivity to C{sub 2} hydrocarbons or synthesis gas. Transient techniques were used to studymore » the methane-surface interactions and the role of lattice oxygen. The selection of the double oxides was made on the hypothesis that the metal oxide would provide an increase interaction with methane whereas the phosphate or lanthanide would provide the sites for oxygen adsorption. The hypothesis behind this selection of catalysts was that increasing the methane interaction with the catalysts would lower the reaction temperature and thus increase the selectivity to the desired products over the total oxidation reaction. In both groups of catalysts the role of Li as a modifier of the selectivity was also studied in detail.« less

Should Controls With Respiratory Symptoms Be Excluded From Case-Control Studies of Pneumonia Etiology? Reflections From the PERCH Study

PubMed Central

Hammitt, Laura L.; Deloria Knoll, Maria; Baggett, Henry C.; Brooks, W. Abdullah; Howie, Stephen R. C.; Kotloff, Karen L.; Levine, Orin S.; Madhi, Shabir A.; Murdoch, David R.; Scott, J. Anthony G.; Thea, Donald M.; Driscoll, Amanda J.; Karron, Ruth A.; Park, Daniel E.; Prosperi, Christine; Zeger, Scott L.; O’Brien, Katherine L.; Feikin, Daniel R.; O’Brien, Katherine L.; Levine, Orin S.; Knoll, Maria Deloria; Feikin, Daniel R.; DeLuca, Andrea N.; Driscoll, Amanda J.; Fu, Wei; Hammitt, Laura L.; Higdon, Melissa M.; Kagucia, E. Wangeci; Karron, Ruth A.; Li, Mengying; Park, Daniel E.; Prosperi, Christine; Wu, Zhenke; Zeger, Scott L.; Watson, Nora L.; Crawley, Jane; Murdoch, David R.; Brooks, W. Abdullah; Endtz, Hubert P.; Zaman, Khalequ; Goswami, Doli; Hossain, Lokman; Jahan, Yasmin; Ashraf, Hasan; Howie, Stephen R. C.; Ebruke, Bernard E.; Antonio, Martin; McLellan, Jessica; Machuka, Eunice; Shamsul, Arifin; Zaman, Syed M.A.; Mackenzie, Grant; Scott, J. Anthony G.; Awori, Juliet O.; Morpeth, Susan C.; Kamau, Alice; Kazungu, Sidi; Kotloff, Karen L.; Tapia, Milagritos D.; Sow, Samba O.; Sylla, Mamadou; Tamboura, Boubou; Onwuchekwa, Uma; Kourouma, Nana; Toure, Aliou; Madhi, Shabir A.; Moore, David P.; Adrian, Peter V.; Baillie, Vicky L.; Kuwanda, Locadiah; Mudau, Azwifarwi; Groome, Michelle J.; Baggett, Henry C.; Thamthitiwat, Somsak; Maloney, Susan A.; Bunthi, Charatdao; Rhodes, Julia; Sawatwong, Pongpun; Akarasewi, Pasakorn; Thea, Donald M.; Mwananyanda, Lawrence; Chipeta, James; Seidenberg, Phil; Mwansa, James; wa Somwe, Somwe; Kwenda, Geoffrey

2017-01-01

Abstract Many pneumonia etiology case-control studies exclude controls with respiratory illness from enrollment or analyses. Herein we argue that selecting controls regardless of respiratory symptoms provides the least biased estimates of pneumonia etiology. We review 3 reasons investigators may choose to exclude controls with respiratory symptoms in light of epidemiologic principles of control selection and present data from the Pneumonia Etiology Research for Child Health (PERCH) study where relevant to assess their validity. We conclude that exclusion of controls with respiratory symptoms will result in biased estimates of etiology. Randomly selected community controls, with or without respiratory symptoms, as long as they do not meet the criteria for case-defining pneumonia, are most representative of the general population from which cases arose and the least subject to selection bias. PMID:28575354

Analysis of Information Content in High-Spectral Resolution Sounders using Subset Selection Analysis

NASA Technical Reports Server (NTRS)

Velez-Reyes, Miguel; Joiner, Joanna

1998-01-01

In this paper, we summarize the results of the sensitivity analysis and data reduction carried out to determine the information content of AIRS and IASI channels. The analysis and data reduction was based on the use of subset selection techniques developed in the linear algebra and statistical community to study linear dependencies in high dimensional data sets. We applied the subset selection method to study dependency among channels by studying the dependency among their weighting functions. Also, we applied the technique to study the information provided by the different levels in which the atmosphere is discretized for retrievals and analysis. Results from the method correlate well with intuition in many respects and point out to possible modifications for band selection in sensor design and number and location of levels in the analysis process.

Methodology Series Module 2: Case-control Studies

PubMed Central

Setia, Maninder Singh

2016-01-01

Case-Control study design is a type of observational study. In this design, participants are selected for the study based on their outcome status. Thus, some participants have the outcome of interest (referred to as cases), whereas others do not have the outcome of interest (referred to as controls). The investigator then assesses the exposure in both these groups. The investigator should define the cases as specifically as possible. Sometimes, definition of a disease may be based on multiple criteria; thus, all these points should be explicitly stated in case definition. An important aspect of selecting a control is that they should be from the same ‘study base’ as that of the cases. We can select controls from a variety of groups. Some of them are: General population; relatives or friends; and hospital patients. Matching is often used in case-control control studies to ensure that the cases and controls are similar in certain characteristics, and it is a useful technique to increase the efficiency of the study. Case-Control studies can usually be conducted relatively faster and are inexpensive – particularly when compared with cohort studies (prospective). It is useful to study rare outcomes and outcomes with long latent periods. This design is not very useful to study rare exposures. Furthermore, they may also be prone to certain biases – selection bias and recall bias. PMID:27057012

Incorporation of economic values into the component traits of a ratio: feed efficiency.

PubMed

Lin, C Y; Aggrey, S E

2013-04-01

Direct selection on a ratio (R) of 2 traits (x1/x2) does not have a mechanism to accommodate the relative economic values (a1 and a2) between x1 and x2 because selection criteria x1/x2 and a1x1/a2x2 rank animals in the same order. This study presented a procedure to incorporate the economic weights into ratio traits through linear transformation. The partial derivatives of a nonlinear profit function evaluated at the means were widely taken as economic weights in the literature. This study showed that the economic weights derived in this manner were erroneous because they actually contain a mixture of actual economic weights and transformation effects. The ratios 1/2 and 2/4 are considered equal by selection on R, but are treated differently by the linear index. In addition, this study presented a unified approach to compare 4 different selection strategies for genetic improvement of ratio traits: linear index (I), selection on the ratio (R), selection on difference between x1 and x2 (D), and selection on x1 alone. This study considered 3 levels of heritability each for variables x1 and x2 and 2 levels of genetic correlations (γG), 2 ratios of means (µ1/µ2), and 4 ratios of phenotypic variances giving a total of 96 scenarios. Linear index I was the most efficient of the 4 criteria compared in all 96 scenarios studied. The superiority of index I over R, D, and selection on x1 alone are particularly remarkable when x1 and x2 have a large difference in heritability and are highly correlated. Selection on x1 alone is an economically viable alternative to criterion I or R for the improvement of ratio traits particularly when x1 is more heritable than x2 and when x2 is costly to measure. Selection on D is more efficient than direct selection on R or selection on x1 alone when x1 is less heritable than x2 and the difference between µ1 and µ2 is small.

For the general internist: a review of relevant 2013 innovations in medical education.

PubMed

Roy, Brita; Willett, Lisa L; Bates, Carol; Duffy, Briar; Dunn, Kathel; Karani, Reena; Chheda, Shobhina G

2015-04-01

We conducted a review of articles published in 2013 to identify high-quality research in medical education that was relevant to general medicine education practice. Our review team consisted of six general internists with expertise in medical education of varying ranks, as well as a professional medical librarian. We manually searched 15 journals in pairs, and performed an online search using the PubMed search engine for all original research articles in medical education published in 2013. From the total 4,181 citations identified, we selected 65 articles considered most relevant to general medicine educational practice. Each team member then independently reviewed and rated the quality of each selected article using the modified Medical Education Research Study Quality Instrument. We then reviewed the quality and relevance of each selected study and grouped them into categories of propensity for inclusion. Nineteen studies were felt to be of adequate quality and were of moderate to high propensity for inclusion. Team members then independently voted for studies they felt to be of the highest relevance and quality within the 19 selected studies. The ten articles with the greatest number of votes were included in the review. We categorized the studies into five general themes: Improving Clinical Skills in UME, Inpatient Clinical Teaching Methods, Advancements in Continuity Clinic, Handoffs/Transitions in Care, and Trainee Assessment. Most studies in our review of the 2013 literature in general medical education were limited to single institutions and non-randomized study designs; we identified significant limitations of each study. Selected articles may inform future research and practice of medical educators.

Teacher-Parent Communication and Parents' Ability to Select Reading Material: A Study of a Baggy Book Program

ERIC Educational Resources Information Center

Lorenz, Kelley M.

2013-01-01

This study examined the effects of a home-reading program on parent-teacher communication and on the ability of parents to select reading material for their children. In this qualitative case study, parents of 4th grade students participated in a reading homework program with their children. Using constructivist theories, the study's…

A Comparative Study of Major OPACs in Selected Academic Libraries for Developing Countries: User Study and Subjective User Evaluation.

ERIC Educational Resources Information Center

Park, Iljong

1997-01-01

A study of five Texas academic libraries provided information on OPAC use by Korean college students to assist system managers select OPACs. The study determined that academic level and age influence preference for the type of OPAC system, that more specific search instructions are needed, and that system menus were the most commonly used source…

Post-parturition habitat selection by elk calves and adult female elk in New Mexico

USGS Publications Warehouse

Pitman, James W.; Cain, James W.; Liley, Stewart; Gould, William R.; Quintana, Nichole T.; Ballard, Warren

2014-01-01

Neonatal survival and juvenile recruitment are crucial to maintaining viable elk (Cervus elaphus) populations. Neonate survival is known to be influenced by many factors, including bed-site selection. Although neonates select the actual bed-site location, they must do so within the larger calf-rearing area selected by the mother. As calves age, habitat selection should change to meet the changing needs of the growing calf. Our main objectives were to characterize habitat selection at 2 spatial scales and in areas with different predator assemblages in New Mexico. We evaluated bed-site selection by calves and calf-rearing area selection by adult females. We captured 108 elk calves by hand and fitted them with ear tag transmitters in two areas in New Mexico: the Valle Vidal and Blue Range Wolf Recovery Area. In both study areas, we found that concealing cover structure and distance to that cover influenced bed-site selection of young calves (i.e., <2 weeks of age). Older calves (i.e., 3–10 weeks of age) still selected areas in relation to distance to cover, but also preferred areas with higher visibility. At the larger spatial scale of calf-rearing habitat selection by the adult female, concealing cover (e.g., rocks, shrubs, and logs) and other variables important to the hiding calves were still in the most supported models, but selection was also influenced by forage availability and indices of forage quality. Studies that seek to obtain insight into microhabitat selection of ungulate neonates should consider selection by the neonate and selection by the adult female, changes in selection as neonates age, and potential selection differences in areas of differing predation risk. By considering these influences together and at multiple scales, studies can achieve a broader understanding of neonatal ungulate habitat requirements. 

Comparative study of minutiae selection algorithms for ISO fingerprint templates

NASA Astrophysics Data System (ADS)

Vibert, B.; Charrier, C.; Le Bars, J.-M.; Rosenberger, C.

2015-03-01

We address the selection of fingerprint minutiae given a fingerprint ISO template. Minutiae selection plays a very important role when a secure element (i.e. a smart-card) is used. Because of the limited capability of computation and memory, the number of minutiae of a stored reference in the secure element is limited. We propose in this paper a comparative study of 6 minutiae selection methods including 2 methods from the literature and 1 like reference (No Selection). Experimental results on 3 fingerprint databases from the Fingerprint Verification Competition show their relative efficiency in terms of performance and computation time.

[The research protocol III. Study population].

PubMed

Arias-Gómez, Jesús; Villasís-Keever, Miguel Ángel; Miranda-Novales, María Guadalupe

2016-01-01

The study population is defined as a set of cases, determined, limited, and accessible, that will constitute the subjects for the selection of the sample, and must fulfill several characteristics and distinct criteria. The objectives of this manuscript are focused on specifying each one of the elements required to make the selection of the participants of a research project, during the elaboration of the protocol, including the concepts of study population, sample, selection criteria and sampling methods. After delineating the study population, the researcher must specify the criteria that each participant has to comply. The criteria that include the specific characteristics are denominated selection or eligibility criteria. These criteria are inclusion, exclusion and elimination, and will delineate the eligible population. The sampling methods are divided in two large groups: 1) probabilistic or random sampling and 2) non-probabilistic sampling. The difference lies in the employment of statistical methods to select the subjects. In every research, it is necessary to establish at the beginning the specific number of participants to be included to achieve the objectives of the study. This number is the sample size, and can be calculated or estimated with mathematical formulas and statistic software.

Fluorescent Photo-conversion: A second chance to label unique cells.

PubMed

Mellott, Adam J; Shinogle, Heather E; Moore, David S; Detamore, Michael S

2015-03-01

Not all cells behave uniformly after treatment in tissue engineering studies. In fact, some treated cells display no signs of treatment or show unique characteristics not consistent with other treated cells. What if the "unique" cells could be isolated from a treated population, and further studied? Photo-convertible reporter proteins, such as Dendra2 , allow for the ability to selectively identify unique cells with a secondary label within a primary labeled treated population. In the current study, select cells were identified and labeled through photo-conversion of Dendra2 -transfected human Wharton's Jelly cells (hWJCs) for the first time. Robust photo-conversion of green-to-red fluorescence was achieved consistently in arbitrarily selected cells, allowing for precise cell identification of select hWJCs. The current study demonstrates a method that offers investigators the opportunity to selectively label and identify unique cells within a treated population for further study or isolation from the treatment population. Photo-convertible reporter proteins, such as Dendra2 , offer the ability over non-photo-convertible reporter proteins, such as green fluorescent protein, to analyze unique individual cells within a treated population, which allows investigators to gain more meaningful information on how a treatment affects all cells within a target population.

Selectivity of beta-adrenergic stimulating and blocking agents.

PubMed

Löfdahl, C G; Svedmyr, N

1984-01-01

Studies have been performed to answer two questions: whether there are subgroups of beta 2-receptors separating effects in bronchial and skeletal muscle and whether beta 1-receptors in asthmatic airways mediate bronchoconstriction. Asthmatic patients have been studied in randomised cross-over trials. Effects on FEV1, heart rate and skeletal muscle tremor have been monitored. In some experimental studies, two new compounds, D2343 and QH-25, have shown a selectivity for beta 2-receptors in bronchial muscle compared to skeletal muscle. Studies in asthmatics did not confirm this. Thus, the beta 2-receptors in the two organs appear to be identical. The clinical effect of beta 1-receptors in the the airways was studied by giving selective beta 1-receptor blocking agents. It was shown that pafenolol , a beta-blocker more beta 1-selective than metoprolol, had less effect on FEV1 than metoprolol given in equipotent beta 1-blocking doses. Beta 1-receptor stimulation with a new selective beta 1-stimulating agent, prenalterol, did not give bronchodilation in doses which gave a significant increase of heart rate. Thus, beta 1-receptors do not contribute to bronchodilation in asthmatic patients.

Cavity trees, snags, and selection cutting: a northern hardwood case study

Treesearch

Laura S. Kenefic; Ralph D. Nyland

2007-01-01

Although traditional application of the selection system includes a focus on high-value trees that may reduce cavities and snags, few studies have quantified those habitat features in managed uneven-aged stands. We examined the effects of single-tree selection cutting on cavity trees and snags in a northern hardwood stand immediately prior to the second cutting....

Correlates of Attitudes toward Academic and Physical Inclusive Practices for Students with Disabilities and Selected Leadership Behaviors among Middle School Principals in North Carolina

ERIC Educational Resources Information Center

Houser, Mary A.; Dickens, Virginia; Hicks, Terence

2011-01-01

The purpose of the study was to examine the relationship between attitudes toward academic and inclusive practices for students with disabilities and selected leadership behaviors (transformational and transactional) among principals in North Carolina. Participants for this study were randomly selected middle school principals from public schools…

Studying Teacher Selection of Resources in an Ultra-Large Scale Interactive System: Does Metadata Guide the Way?

ERIC Educational Resources Information Center

Abramovich, Samuel; Schunn, Christian

2012-01-01

Ultra-large-scale interactive systems on the Internet have begun to change how teachers prepare for instruction, particularly in regards to resource selection. Consequently, it is important to look at how teachers are currently selecting resources beyond content or keyword search. We conducted a two-part observational study of an existing popular…

Comparing and Managing the Relative Importance and Ranking of Reasons for Selecting the Masters' of Business Administration Program

ERIC Educational Resources Information Center

Snyder, Ronald L.; Kizer, Lee E.; Mutjaba, Bahaudin G.; Khanfar, Nile M.

2009-01-01

This paper reports the findings of a study involving the selection process that adult graduate students used when choosing to pursue and attain an advanced business degree at Southern Wesleyan University. This study includes a comparison of the initial priorities used in the selection process to priorities that remain important in retrospect. The…

A Study of Vocational Education as a Factor in Selecting a Community for a Manufacturing Plant Site.

ERIC Educational Resources Information Center

Dean, Ernest H.

The purpose of the study was to determine the factors considered by industrialists as they select communities in which to locate their new manufacturing plants, and to place the relative importance upon vocational-technical education as a factor in the plant site selection process. The three populations consisted of 113 companies of varying sizes…

A Careful Look at Modern Case Selection Methods

ERIC Educational Resources Information Center

Herron, Michael C.; Quinn, Kevin M.

2016-01-01

Case studies appear prominently in political science, sociology, and other social science fields. A scholar employing a case study research design in an effort to estimate causal effects must confront the question, how should cases be selected for analysis? This question is important because the results derived from a case study research program…

Factors Related to the Selection of Information Sources: A Study of Ramkhamhaeng University Regional Campuses Graduate Students

ERIC Educational Resources Information Center

Angchun, Peemasak

2011-01-01

This study assessed students' satisfaction with Ramkhamhaeng University regional library services (RURLs) and the perceived quality of information retrieved from other information sources. In particular, this study investigated factors relating to regional students' selection of information sources to meet their information needs. The researcher…

A Different World: African American, First Generation College Women at a Selective University

ERIC Educational Resources Information Center

Johnson, Jennifer Michelle

2013-01-01

The purpose of this study was to gain a better understanding of the academic and social experiences of African American, first generation college students attending a selective university. Following interpretive case study methodology, the major research questions guiding this study were: How do African American, first generation college students…

Selective Attentional Effects of Textbook Study Questions on Student Learning in Science.

ERIC Educational Resources Information Center

Holliday, William G.

1981-01-01

Reports results of a study testing a selective attentional model which predicted that textbook study questions adjunct to a flow diagram will focus students' attention more upon questioned information and less upon nonquestioned information. A picture-word diagram describing biogeochemical cycles to high school biology students (N=176) was used.…

Greek Organization Membership and Collegiate Outcomes at an Elite, Private University

ERIC Educational Resources Information Center

Walker, Jay K.; Martin, Nathan D.; Hussey, Andrew

2015-01-01

In this study, we use detailed survey and institutional data from a prospective panel study of students attending a highly selective, private university to examine the effects of fraternity or sorority membership on a range of collegiate outcomes. Previous research has given insufficient attention to selection issues inherent in the study of…

Secondary Mathematics Pre-Service Teachers' Processes of Selection and Integration of Technology

ERIC Educational Resources Information Center

Uzan, Erol

2017-01-01

This study investigated secondary mathematics pre-service teachers' (PSTs) knowledge of resources in terms of digital technologies, and explored the processes of both selection and integration of technology into their lesson plans. This study employed a case study design. Participants were six secondary mathematics PSTs who enrolled in a methods…

Rapid discrimination of Isaria javanica and Isaria poprawskii from Isaria spp. using high resolution DNA melting assays

USDA-ARS?s Scientific Manuscript database

The current study evaluates the potential of using high resolution DNA melting assays to discriminate species in the genus, Isaria. The study utilizes a previously identified 103 base pair PCR amplicon, which was reported to be selective for Isaria fumosorosea. Our study finds the amplicon selective...

Geostationary platform systems concepts definition study. Volume 2: Technical, book 1

NASA Technical Reports Server (NTRS)

1980-01-01

The initial selection and definition of operational geostationary platform concepts is discussed. Candidate geostationary platform missions and payloads were identified from COMSAT, Aerospace, and NASA studies. These missions and payloads were cataloged; classified with to communications, military, or scientific uses; screened for application and compatibility with geostationary platforms; and analyzed to identify platform requirements. Two platform locations were then selected (Western Hemisphere - 110 deg W, and Atlantic - 15 deg W), and payloads allocated based on nominal and high traffic models. Trade studies were performed leading to recommendation of selected concepts. Of 30 Orbit Transfer Vehicle (0TV) configuration and operating mode options identified, 18 viable candidates compatible with the operational geostationary platform missions were selected for analysis. Each was considered using four platform operational modes - 8 or 16 year life, and serviced or nonserviced, providing a total of 72 OTV/platform-mode options. For final trade study concept selection, a cost program was developed considering payload and platform costs and weight; transportation unit and total costs for the shuttle and OTV; and operational costs such as assembly or construction time, mating time, and loiter time. Servicing costs were added for final analysis and recommended selection.

US EPA Base Study Standard Operating Procedure for Building Recruiting

EPA Pesticide Factsheets

Building recruiting for the BASE study is defined by a random selection of buildings within cities of population exceeding 100,000 inhabitants and located in selected climatic regions of the United States.

Promotion of cooperation by selective group extinction

NASA Astrophysics Data System (ADS)

Böttcher, Marvin A.; Nagler, Jan

2016-06-01

Multilevel selection is an important organizing principle that crucially underlies evolutionary processes from the emergence of cells to eusociality and the economics of nations. Previous studies on multilevel selection assumed that the effective higher-level selection emerges from lower-level reproduction. This leads to selection among groups, although only individuals reproduce. We introduce selective group extinction, where groups die with a probability inversely proportional to their group fitness. When accounting for this the critical benefit-to-cost ratio is substantially lowered. Because in game theory and evolutionary dynamics the degree of cooperation crucially depends on this ratio above which cooperation emerges, previous studies may have substantially underestimated the establishment and maintenance of cooperation.

Selection of representative emerging micropollutants for drinking water treatment studies: a systematic approach.

PubMed

Jin, Xiaohui; Peldszus, Sigrid

2012-01-01

Micropollutants remain of concern in drinking water, and there is a broad interest in the ability of different treatment processes to remove these compounds. To gain a better understanding of treatment effectiveness for structurally diverse compounds and to be cost effective, it is necessary to select a small set of representative micropollutants for experimental studies. Unlike other approaches to-date, in this research micropollutants were systematically selected based solely on their physico-chemical and structural properties that are important in individual water treatment processes. This was accomplished by linking underlying principles of treatment processes such as coagulation/flocculation, oxidation, activated carbon adsorption, and membrane filtration to compound characteristics and corresponding molecular descriptors. A systematic statistical approach not commonly used in water treatment was then applied to a compound pool of 182 micropollutants (identified from the literature) and their relevant calculated molecular descriptors. Principal component analysis (PCA) was used to summarize the information residing in this large dataset. D-optimal onion design was then applied to the PCA results to select structurally representative compounds that could be used in experimental treatment studies. To demonstrate the applicability and flexibility of this selection approach, two sets of 22 representative micropollutants are presented. Compounds in the first set are representative when studying a range of water treatment processes (coagulation/flocculation, oxidation, activated carbon adsorption, and membrane filtration), whereas the second set shows representative compounds for ozonation and advanced oxidation studies. Overall, selected micropollutants in both lists are structurally diverse, have wide-ranging physico-chemical properties and cover a large spectrum of applications. The systematic compound selection approach presented here can also be adjusted to fit individual research needs with respect to type of micropollutants, treatment processes and number of compounds selected. Copyright © 2011 Elsevier B.V. All rights reserved.

Validation of sentinel lymph node biopsy in breast cancer women N1-N2 with complete axillary response after neoadjuvant chemotherapy. Multicentre study in Tarragona.

PubMed

Carrera, D; de la Flor, M; Galera, J; Amillano, K; Gomez, M; Izquierdo, V; Aguilar, E; López, S; Martínez, M; Martínez, S; Serra, J M; Pérez, M; Martin, L

2016-01-01

The aim of our study was to evaluate sentinel lymph node biopsy as a diagnostic test for assessing the presence of residual metastatic axillary lymph nodes after neoadjuvant chemotherapy, replacing the need for a lymphadenectomy in negative selective lymph node biopsy patients. A multicentre, diagnostic validation study was conducted in the province of Tarragona, on women with T1-T3, N1-N2 breast cancer, who presented with a complete axillary response after neoadjuvant chemotherapy. Study procedures consisted of performing an selective lymph node biopsy followed by lymphadenectomy. A total of 53 women were included in the study. Surgical detection rate was 90.5% (no sentinel node found in 5 patients). Histopathological analysis of the lymphadenectomy showed complete disease regression of axillary nodes in 35.4% (17/48) of the patients, and residual axillary node involvement in 64.6% (31/48) of them. In lymphadenectomy positive patients, 28 had a positive selective lymph node biopsy (true positive), while 3 had a negative selective lymph node biopsy (false negative). Of the 28 true selective lymph node biopsy positives, the sentinel node was the only positive node in 10 cases. All lymphadenectomy negative cases were selective lymph node biopsy negative. These data yield a sensitivity of 93.5%, a false negative rate of 9.7%, and a global test efficiency of 93.7%. Selective lymph node biopsy after chemotherapy in patients with a complete axillary response provides valid and reliable information regarding axillary status after neoadjuvant treatment, and might prevent lymphadenectomy in cases with negative selective lymph node biopsy. Copyright © 2016 Elsevier España, S.L.U. and SEMNIM. All rights reserved.

Burglar Target Selection

PubMed Central

Townsley, Michael; Bernasco, Wim; Ruiter, Stijn; Johnson, Shane D.; White, Gentry; Baum, Scott

2015-01-01

Objectives: This study builds on research undertaken by Bernasco and Nieuwbeerta and explores the generalizability of a theoretically derived offender target selection model in three cross-national study regions. Methods: Taking a discrete spatial choice approach, we estimate the impact of both environment- and offender-level factors on residential burglary placement in the Netherlands, the United Kingdom, and Australia. Combining cleared burglary data from all study regions in a single statistical model, we make statistical comparisons between environments. Results: In all three study regions, the likelihood an offender selects an area for burglary is positively influenced by proximity to their home, the proportion of easily accessible targets, and the total number of targets available. Furthermore, in two of the three study regions, juvenile offenders under the legal driving age are significantly more influenced by target proximity than adult offenders. Post hoc tests indicate the magnitudes of these impacts vary significantly between study regions. Conclusions: While burglary target selection strategies are consistent with opportunity-based explanations of offending, the impact of environmental context is significant. As such, the approach undertaken in combining observations from multiple study regions may aid criminology scholars in assessing the generalizability of observed findings across multiple environments. PMID:25866418

2nd Generation Reusable Launch Vehicle (2G RLV). Revised

NASA Technical Reports Server (NTRS)

Matlock, Steve; Sides, Steve; Kmiec, Tom; Arbogast, Tim; Mayers, Tom; Doehnert, Bill

2001-01-01

This is a revised final report and addresses all of the work performed on this program. Specifically, it covers vehicle architecture background, definition of six baseline engine cycles, reliability baseline (space shuttle main engine QRAS), and component level reliability/performance/cost for the six baseline cycles, and selection of 3 cycles for further study. This report further addresses technology improvement selection and component level reliability/performance/cost for the three cycles selected for further study, as well as risk reduction plans, and recommendation for future studies.

Substitution rate and natural selection in parvovirus B19

PubMed Central

Stamenković, Gorana G.; Ćirković, Valentina S.; Šiljić, Marina M.; Blagojević, Jelena V.; Knežević, Aleksandra M.; Joksić, Ivana D.; Stanojević, Maja P.

2016-01-01

The aim of this study was to estimate substitution rate and imprints of natural selection on parvovirus B19 genotype 1. Studied datasets included 137 near complete coding B19 genomes (positions 665 to 4851) for phylogenetic and substitution rate analysis and 146 and 214 partial genomes for selection analyses in open reading frames ORF1 and ORF2, respectively, collected 1973–2012 and including 9 newly sequenced isolates from Serbia. Phylogenetic clustering assigned majority of studied isolates to G1A. Nucleotide substitution rate for total coding DNA was 1.03 (0.6–1.27) x 10−4 substitutions/site/year, with higher values for analyzed genome partitions. In spite of the highest evolutionary rate, VP2 codons were found to be under purifying selection with rare episodic positive selection, whereas codons under diversifying selection were found in the unique part of VP1, known to contain B19 immune epitopes important in persistent infection. Analyses of overlapping gene regions identified nucleotide positions under opposite selective pressure in different ORFs, suggesting complex evolutionary mechanisms of nucleotide changes in B19 viral genomes. PMID:27775080

Archaeological data reveal slow rates of evolution during plant domestication.

PubMed

Purugganan, Michael D; Fuller, Dorian Q

2011-01-01

Domestication is an evolutionary process of species divergence in which morphological and physiological changes result from the cultivation/tending of plant or animal species by a mutualistic partner, most prominently humans. Darwin used domestication as an analogy to evolution by natural selection although there is strong debate on whether this process of species evolution by human association is an appropriate model for evolutionary study. There is a presumption that selection under domestication is strong and most models assume rapid evolution of cultivated species. Using archaeological data for 11 species from 60 archaeological sites, we measure rates of evolution in two plant domestication traits--nonshattering and grain/seed size increase. Contrary to previous assumptions, we find the rates of phenotypic evolution during domestication are slow, and significantly lower or comparable to those observed among wild species subjected to natural selection. Our study indicates that the magnitudes of the rates of evolution during the domestication process, including the strength of selection, may be similar to those measured for wild species. This suggests that domestication may be driven by unconscious selection pressures similar to that observed for natural selection, and the study of the domestication process may indeed prove to be a valid model for the study of evolutionary change. © 2010 The Author(s). Evolution© 2010 The Society for the Study of Evolution.

The COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) and how to select an outcome measurement instrument.

PubMed

Mokkink, Lidwine B; Prinsen, Cecilia A C; Bouter, Lex M; Vet, Henrica C W de; Terwee, Caroline B

2016-01-19

COSMIN (COnsensus-based Standards for the selection of health Measurement INstruments) is an initiative of an international multidisciplinary team of researchers who aim to improve the selection of outcome measurement instruments both in research and in clinical practice by developing tools for selecting the most appropriate available instrument. In this paper these tools are described, i.e. the COSMIN taxonomy and definition of measurement properties; the COSMIN checklist to evaluate the methodological quality of studies on measurement properties; a search filter for finding studies on measurement properties; a protocol for systematic reviews of outcome measurement instruments; a database of systematic reviews of outcome measurement instruments; and a guideline for selecting outcome measurement instruments for Core Outcome Sets in clinical trials. Currently, we are updating the COSMIN checklist, particularly the standards for content validity studies. Also new standards for studies using Item Response Theory methods will be developed. Additionally, in the future we want to develop standards for studies on the quality of non-patient reported outcome measures, such as clinician-reported outcomes and performance-based outcomes. In summary, we plea for more standardization in the use of outcome measurement instruments, for conducting high quality systematic reviews on measurement instruments in which the best available outcome measurement instrument is recommended, and for stopping the use of poor outcome measurement instruments.

Visual Tuning Properties of Genetically Identified Layer 2/3 Neuronal Types in the Primary Visual Cortex of Cre-Transgenic Mice

PubMed Central

Zariwala, Hatim A.; Madisen, Linda; Ahrens, Kurt F.; Bernard, Amy; Lein, Edward S.; Jones, Allan R.; Zeng, Hongkui

2011-01-01

The putative excitatory and inhibitory cell classes within the mouse primary visual cortex V1 have different functional properties as studied using recording microelectrode. Excitatory neurons show high selectivity for the orientation angle of moving gratings while the putative inhibitory neurons show poor selectivity. However, the study of selectivity of the genetically identified interneurons and their subtypes remain controversial. Here we use novel Cre-driver and reporter mice to identify genetic subpopulations in vivo for two-photon calcium dye imaging: Wfs1(+)/Gad1(−) mice that labels layer 2/3 excitatory cell population and Pvalb(+)/Gad1(+) mice that labels a genetic subpopulation of inhibitory neurons. The cells in both mice were identically labeled with a tdTomato protein, visible in vivo, using a Cre-reporter line. We found that the Wfs1(+) cells exhibited visual tuning properties comparable to the excitatory population, i.e., high selectivity and tuning to the angle, direction, and spatial frequency of oriented moving gratings. The functional tuning of Pvalb(+) neurons was consistent with previously reported narrow-spiking interneurons in microelectrode studies, exhibiting poorer selectivity than the excitatory neurons. This study demonstrates the utility of Cre-transgenic mouse technology in selective targeting of subpopulations of neurons and makes them amenable to structural, functional, and connectivity studies. PMID:21283555

The COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) and how to select an outcome measurement instrument

PubMed Central

Mokkink, Lidwine B.; Prinsen, Cecilia A. C.; Bouter, Lex M.; de Vet, Henrica C. W.; Terwee, Caroline B.

2016-01-01

Background: COSMIN (COnsensus-based Standards for the selection of health Measurement INstruments) is an initiative of an international multidisciplinary team of researchers who aim to improve the selection of outcome measurement instruments both in research and in clinical practice by developing tools for selecting the most appropriate available instrument. Method: In this paper these tools are described, i.e. the COSMIN taxonomy and definition of measurement properties; the COSMIN checklist to evaluate the methodological quality of studies on measurement properties; a search filter for finding studies on measurement properties; a protocol for systematic reviews of outcome measurement instruments; a database of systematic reviews of outcome measurement instruments; and a guideline for selecting outcome measurement instruments for Core Outcome Sets in clinical trials. Currently, we are updating the COSMIN checklist, particularly the standards for content validity studies. Also new standards for studies using Item Response Theory methods will be developed. Additionally, in the future we want to develop standards for studies on the quality of non-patient reported outcome measures, such as clinician-reported outcomes and performance-based outcomes. Conclusions: In summary, we plea for more standardization in the use of outcome measurement instruments, for conducting high quality systematic reviews on measurement instruments in which the best available outcome measurement instrument is recommended, and for stopping the use of poor outcome measurement instruments. PMID:26786084

A Study of Psychological Distress in Two Cohorts of First-Year Medical Students that Underwent Different Admission Selection Processes

PubMed Central

Yusoff, Muhamad Saiful Bahri; Rahim, Ahmad Fuad Abdul; Baba, Abdul Aziz; Ismail, Shaiful Bahari; Esa, Ab Rahman

2012-01-01

Background: Medical training is often regarded as a stressful period. Studies have previously found that 21.6%–50% of medical students experience significant psychological distress. The present study compared the prevalence and levels of psychological distress between 2 cohorts of first-year medical students that underwent different admission selection processes. Methods: A comparative cross-sectional study was conducted by comparing 2 cohorts of first-year medical students; 1 group (cohort 1) was selected based purely on academic merit (2008/2009 cohort) and the other group (cohort 2) was selected based on academic merit, psychometric assessment, and interview performance (2009/2010 cohort). Their distress levels were measured by the General Health Questionnaire, and scores higher than 3 were considered indicative of significant psychological distress. Results: The prevalence (P = 0.003) and levels (P = 0.001) of psychological distress were significantly different between the 2 cohorts. Cohort 1 had 1.2–3.3 times higher risk of developing psychological distress compared to cohort 2 (P = 0.007). Conclusion: Cohort 2 had better psychological health than cohort 1 and was less likely to develop psychological distress. This study provided evidence of a potential benefit of multimodal student selection based on academic merit, psychometric assessment, and interview performance. This selection process might identify medical students who will maintain better psychological health. PMID:23610547

Performance and anthropometric characteristics of prospective elite junior Australian footballers: a case study in one junior team.

PubMed

Veale, James P; Pearce, Alan J; Koehn, Stefan; Carlson, John S

2008-04-01

The aim of the study was to compare anthropometric and physical performance data of players who were selected for a Victorian elite junior U18 Australian rules football squad. Prior to the selection of the final training squad, 54 players were assessed using a battery of standard anthropometric and physical performance tests. Multivariate analysis (MANOVA) showed significant (p<0.05) differences between selected and non-selected players when height, mass, 20-m sprint, agility and vertical jump height were considered collectively. Univariate analysis revealed that the vertical jump was the only significant (p<0.05) individual test and a near significant trend (p=0.07) for height differentiating between selected and non-selected players with medium effect sizes for all other tests except endurance. In this elite junior football squad, physical characteristics can be observed that discriminate between players selected and non-selected, and demonstrates the value of physical fitness testing within the talent identification process of junior (16-18 years) players for squad and/or team selection. Based on MANOVA results, the findings from this study suggest team selection appeared to be related to a generally higher performance across the range of tests. Further, age was not a confounding variable as players selected tended to be younger than those non-selected. These findings reflect the general consensus that, in state-based junior competition, there is evidence of promoting overall player development, selecting those who are generally able to fulfil a range of positions and selecting players on their potential.

Artificial selection increased body weight but induced increase of runs of homozygosity in Hanwoo cattle

PubMed Central

Kim, Kwondo; Jung, Jaehoon; Caetano-Anollés, Kelsey; Sung, Samsun; Yoo, DongAhn; Choi, Bong-Hwan; Kim, Hyung-Chul; Jeong, Jin-Young; Cho, Yong-Min; Park, Eung-Woo; Choi, Tae-Jeong; Park, Byoungho; Lim, Dajeong

2018-01-01

Artificial selection has been demonstrated to have a rapid and significant effect on the phenotype and genome of an organism. However, most previous studies on artificial selection have focused solely on genomic sequences modified by artificial selection or genomic sequences associated with a specific trait. In this study, we generated whole genome sequencing data of 126 cattle under artificial selection, and 24,973,862 single nucleotide variants to investigate the relationship among artificial selection, genomic sequences and trait. Using runs of homozygosity detected by the variants, we showed increase of inbreeding for decades, and at the same time demonstrated a little influence of recent inbreeding on body weight. Also, we could identify ~0.2 Mb runs of homozygosity segment which may be created by recent artificial selection. This approach may aid in development of genetic markers directly influenced by artificial selection, and provide insight into the process of artificial selection. PMID:29561881

The quality of control groups in nonrandomized studies published in the Journal of Hand Surgery.

PubMed

Johnson, Shepard P; Malay, Sunitha; Chung, Kevin C

2015-01-01

To evaluate control group selection in nonrandomized studies published in the Journal of Hand Surgery American (JHS). We reviewed all papers published in JHS in 2013 to identify studies that used nonrandomized control groups. Data collected included type of study design and control group characteristics. We then appraised studies to determine whether authors discussed confounding and selection bias and how they controlled for confounding. Thirty-seven nonrandomized studies were published in JHS in 2013. The source of control was either the same institution as the study group, a different institution, a database, or not provided in the manuscript. Twenty-nine (78%) studies statistically compared key characteristics between control and study group. Confounding was controlled with matching, exclusion criteria, or regression analysis. Twenty-two (59%) papers explicitly discussed the threat of confounding and 18 (49%) identified sources of selection bias. In our review of nonrandomized studies published in JHS, papers had well-defined controls that were similar to the study group, allowing for reasonable comparisons. However, we identified substantial confounding and bias that were not addressed as explicit limitations, which might lead the reader to overestimate the scientific validity of the data. Incorporating a brief discussion of control group selection in scientific manuscripts should help readers interpret the study more appropriately. Authors, reviewers, and editors should strive to address this component of clinical importance. Copyright © 2015 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Observational methods in comparative effectiveness research.

PubMed

Concato, John; Lawler, Elizabeth V; Lew, Robert A; Gaziano, J Michael; Aslan, Mihaela; Huang, Grant D

2010-12-01

Comparative effectiveness research (CER) may be defined informally as an assessment of available options for treating specific medical conditions in selected groups of patients. In this context, the most prominent features of CER are the various patient populations, medical ailments, and treatment options involved in any particular project. Yet, each research investigation also has a corresponding study design or "architecture," and in patient-oriented research a common distinction used to describe such designs are randomized controlled trials (RCTs) versus observational studies. The purposes of this overview, with regard to CER, are to (1) understand how observational studies can provide accurate results, comparable to RCTs; (2) recognize strategies used in selected newer methods for conducting observational studies; (3) review selected observational studies from the Veterans Health Administration; and (4) appreciate the importance of fundamental methodological principles when conducting or evaluating individual studies. Published by Elsevier Inc.

Arctic Small Rodents Have Diverse Diets and Flexible Food Selection

PubMed Central

Soininen, Eeva M.; Ravolainen, Virve T.; Bråthen, Kari Anne; Yoccoz, Nigel G.; Gielly, Ludovic; Ims, Rolf A.

2013-01-01

The ecology of small rodent food selection is poorly understood, as mammalian herbivore food selection theory has mainly been developed by studying ungulates. Especially, the effect of food availability on food selection in natural habitats where a range of food items are available is unknown. We studied diets and selectivity of grey-sided voles (Myodes rufocanus) and tundra voles (Microtus oeconomus), key herbivores in European tundra ecosystems, using DNA metabarcoding, a novel method enabling taxonomically detailed diet studies. In order to cover the range of food availabilities present in the wild, we employed a large-scale study design for sampling data on food availability and vole diets. Both vole species had ingested a range of plant species and selected particularly forbs and grasses. Grey-sided voles also selected ericoid shrubs and tundra voles willows. Availability of a food item rarely affected its utilization directly, although seasonal changes of diets and selection suggest that these are positively correlated with availability. Moreover, diets and selectivity were affected by availability of alternative food items. These results show that the focal sub-arctic voles have diverse diets and flexible food preferences and rarely compensate low availability of a food item with increased searching effort. Diet diversity itself is likely to be an important trait and has previously been underrated owing to methodological constraints. We suggest that the roles of alternative food item availability and search time limitations for small rodent feeding ecology should be investigated. Nomenclature Annotated Checklist of the Panarctic Flora (PAF), Vascular plants. Available at: http://nhm2.uio.no/paf/, accessed 15.6.2012. PMID:23826371

The importance of protein in leaf selection of folivorous primates.

PubMed

Ganzhorn, Joerg U; Arrigo-Nelson, Summer J; Carrai, Valentina; Chalise, Mukesh K; Donati, Giuseppe; Droescher, Iris; Eppley, Timothy M; Irwin, Mitchell T; Koch, Flávia; Koenig, Andreas; Kowalewski, Martin M; Mowry, Christopher B; Patel, Erik R; Pichon, Claire; Ralison, Jose; Reisdorff, Christoph; Simmen, Bruno; Stalenberg, Eleanor; Starrs, Danswell; Terboven, Juana; Wright, Patricia C; Foley, William J

2017-04-01

Protein limitation has been considered a key factor in hypotheses on the evolution of life history and animal communities, suggesting that animals should prioritize protein in their food choice. This contrasts with the limited support that food selection studies have provided for such a priority in nonhuman primates, particularly for folivores. Here, we suggest that this discrepancy can be resolved if folivores only need to select for high protein leaves when average protein concentration in the habitat is low. To test the prediction, we applied meta-analyses to analyze published and unpublished results of food selection for protein and fiber concentrations from 24 studies (some with multiple species) of folivorous primates. To counter potential methodological flaws, we differentiated between methods analyzing total nitrogen and soluble protein concentrations. We used a meta-analysis to test for the effect of protein on food selection by primates and found a significant effect of soluble protein concentrations, but a non-significant effect for total nitrogen. Furthermore, selection for soluble protein was reinforced in forests where protein was less available. Selection for low fiber content was significant but unrelated to the fiber concentrations in representative leaf samples of a given forest. There was no relationship (either negative or positive) between the concentration of protein and fiber in the food or in representative samples of leaves. Overall our study suggests that protein selection is influenced by the protein availability in the environment, explaining the sometimes contradictory results in previous studies on protein selection. Am. J. Primatol. 79:e22550, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

GWASinlps: Nonlocal prior based iterative SNP selection tool for genome-wide association studies.

PubMed

Sanyal, Nilotpal; Lo, Min-Tzu; Kauppi, Karolina; Djurovic, Srdjan; Andreassen, Ole A; Johnson, Valen E; Chen, Chi-Hua

2018-06-19

Multiple marker analysis of the genome-wide association study (GWAS) data has gained ample attention in recent years. However, because of the ultra high-dimensionality of GWAS data, such analysis is challenging. Frequently used penalized regression methods often lead to large number of false positives, whereas Bayesian methods are computationally very expensive. Motivated to ameliorate these issues simultaneously, we consider the novel approach of using nonlocal priors in an iterative variable selection framework. We develop a variable selection method, named, iterative nonlocal prior based selection for GWAS, or GWASinlps, that combines, in an iterative variable selection framework, the computational efficiency of the screen-and-select approach based on some association learning and the parsimonious uncertainty quantification provided by the use of nonlocal priors. The hallmark of our method is the introduction of 'structured screen-and-select' strategy, that considers hierarchical screening, which is not only based on response-predictor associations, but also based on response-response associations, and concatenates variable selection within that hierarchy. Extensive simulation studies with SNPs having realistic linkage disequilibrium structures demonstrate the advantages of our computationally efficient method compared to several frequentist and Bayesian variable selection methods, in terms of true positive rate, false discovery rate, mean squared error, and effect size estimation error. Further, we provide empirical power analysis useful for study design. Finally, a real GWAS data application was considered with human height as phenotype. An R-package for implementing the GWASinlps method is available at https://cran.r-project.org/web/packages/GWASinlps/index.html. Supplementary data are available at Bioinformatics online.

Selecting climate change scenarios for regional hydrologic impact studies based on climate extremes indices

NASA Astrophysics Data System (ADS)

Seo, Seung Beom; Kim, Young-Oh; Kim, Youngil; Eum, Hyung-Il

2018-04-01

When selecting a subset of climate change scenarios (GCM models), the priority is to ensure that the subset reflects the comprehensive range of possible model results for all variables concerned. Though many studies have attempted to improve the scenario selection, there is a lack of studies that discuss methods to ensure that the results from a subset of climate models contain the same range of uncertainty in hydrologic variables as when all models are considered. We applied the Katsavounidis-Kuo-Zhang (KKZ) algorithm to select a subset of climate change scenarios and demonstrated its ability to reduce the number of GCM models in an ensemble, while the ranges of multiple climate extremes indices were preserved. First, we analyzed the role of 27 ETCCDI climate extremes indices for scenario selection and selected the representative climate extreme indices. Before the selection of a subset, we excluded a few deficient GCM models that could not represent the observed climate regime. Subsequently, we discovered that a subset of GCM models selected by the KKZ algorithm with the representative climate extreme indices could not capture the full potential range of changes in hydrologic extremes (e.g., 3-day peak flow and 7-day low flow) in some regional case studies. However, the application of the KKZ algorithm with a different set of climate indices, which are correlated to the hydrologic extremes, enabled the overcoming of this limitation. Key climate indices, dependent on the hydrologic extremes to be projected, must therefore be determined prior to the selection of a subset of GCM models.

Selective impairment of decision making under ambiguity in alexithymia.

PubMed

Zhang, Lei; Wang, Xue; Zhu, Yu; Li, Hongchen; Zhu, Chunyan; Yu, Fengqiong; Wang, Kai

2017-11-28

Alexithymia is characterised by difficulties identifying and describing emotions. Few studies have investigated how alexithymia influences decision-making under different conditions (ambiguity and risk). This study aimed to examine whether alexithymia contributes to impairment in decision-making. This study included 42 participants with high scores in the Chinese version of Toronto Alexithymia Scale (alexithymia group), and 44 matched subjects with low scores (control group). Decision-making was measured using the Iowa Gambling Task (IGT) and the Game of Dice Task (GDT). The main findings of this study revealed selective deficits in IGT performance for the alexithymia group, while GDT performance was unimpaired when compared with the control group. In IGT, total netscores were lower for the alexithymia group compared to the control group, particularly with regard to block 5. Moreover, the alexithymia individuals selected significantly more adverse cards than the controls, indicating significant decision-making impairments. Alexithymia selectively influences decision-making under ambiguity.

Antitumor Efficacy Testing in Rodents

PubMed Central

2008-01-01

The preclinical research and human clinical trials necessary for developing anticancer therapeutics are costly. One contributor to these costs is preclinical rodent efficacy studies, which, in addition to the costs associated with conducting them, often guide the selection of agents for clinical development. If inappropriate or inaccurate recommendations are made on the basis of these preclinical studies, then additional costs are incurred. In this commentary, I discuss the issues associated with preclinical rodent efficacy studies. These include the identification of proper preclinical efficacy models, the selection of appropriate experimental endpoints, and the correct statistical evaluation of the resulting data. I also describe important experimental design considerations, such as selecting the drug vehicle, optimizing the therapeutic treatment plan, properly powering the experiment by defining appropriate numbers of replicates in each treatment arm, and proper randomization. Improved preclinical selection criteria can aid in reducing unnecessary human studies, thus reducing the overall costs of anticancer drug development. PMID:18957675

Should Controls With Respiratory Symptoms Be Excluded From Case-Control Studies of Pneumonia Etiology? Reflections From the PERCH Study.

PubMed

Higdon, Melissa M; Hammitt, Laura L; Deloria Knoll, Maria; Baggett, Henry C; Brooks, W Abdullah; Howie, Stephen R C; Kotloff, Karen L; Levine, Orin S; Madhi, Shabir A; Murdoch, David R; Scott, J Anthony G; Thea, Donald M; Driscoll, Amanda J; Karron, Ruth A; Park, Daniel E; Prosperi, Christine; Zeger, Scott L; O'Brien, Katherine L; Feikin, Daniel R

2017-06-15

Many pneumonia etiology case-control studies exclude controls with respiratory illness from enrollment or analyses. Herein we argue that selecting controls regardless of respiratory symptoms provides the least biased estimates of pneumonia etiology. We review 3 reasons investigators may choose to exclude controls with respiratory symptoms in light of epidemiologic principles of control selection and present data from the Pneumonia Etiology Research for Child Health (PERCH) study where relevant to assess their validity. We conclude that exclusion of controls with respiratory symptoms will result in biased estimates of etiology. Randomly selected community controls, with or without respiratory symptoms, as long as they do not meet the criteria for case-defining pneumonia, are most representative of the general population from which cases arose and the least subject to selection bias. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

Green supply chain management strategy selection using analytic network process: case study at PT XYZ

NASA Astrophysics Data System (ADS)

Adelina, W.; Kusumastuti, R. D.

2017-01-01

This study is about business strategy selection for green supply chain management (GSCM) for PT XYZ by using Analytic Network Process (ANP). GSCM is initiated as a response to reduce environmental impacts from industrial activities. The purposes of this study are identifying criteria and sub criteria in selecting GSCM Strategy, and analysing a suitable GSCM strategy for PT XYZ. This study proposes ANP network with 6 criteria and 29 sub criteria, which are obtained from the literature and experts’ judgements. One of the six criteria contains GSCM strategy options, namely risk-based strategy, efficiency-based strategy, innovation-based strategy, and closed loop strategy. ANP solves complex GSCM strategy-selection by using a more structured process and considering green perspectives from experts. The result indicates that innovation-based strategy is the most suitable green supply chain management strategy for PT XYZ.

Phenotypic selection to increase floral scent emission, but not flower size or colour in bee-pollinated Penstemon digitalis.

PubMed

Parachnowitsch, Amy L; Raguso, Robert A; Kessler, André

2012-08-01

Fragrance is a putatively important character in the evolution of flowering plants, but natural selection on scent is rarely studied and thus poorly understood. We characterized floral scent composition and emission in a common garden of Penstemon digitalis from three nearby source populations. We measured phenotypic selection on scent as well as floral traits more frequently examined, such as floral phenology, display size, corolla pigment, and inflorescence height. Scent differed among populations in a common garden, underscoring the potential for scent to be shaped by differential selection pressures. Phenotypic selection on flower number and display size was strong. However, selection favoured scent rather than flower size or colour, suggesting that smelling stronger benefits reproductive success in P. digitalis. Linalool was a direct target of selection and its high frequency in floral-scent bouquets suggests that further studies of both pollinator- and antagonist-mediated selection on this compound would further our understanding of scent evolution. Our results indicate that chemical dimensions of floral display are just as likely as other components to experience selective pressure in a nonspecialized flowering herb. Therefore, studies that integrate visual and chemical floral traits should better reflect the true nature of floral evolutionary ecology. © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.

A Case Study of the Progressive Impact of School-Wide Positive Behavior Support on Five Selected Student Performance Factors in a Missouri K-12 Alternative Public School

ERIC Educational Resources Information Center

Becker, Colleen Gilday

2013-01-01

The purpose of this case study was to examine the School-Wide Positive Behavior Support (SWPBS) impact on five selected student performance factors. A literature review revealed there have been many SWPBS research studies regarding traditional public schools. However, there have not been any published empirical SWPBS studies involving K-12…

Selection of Surrogate Bacteria for Use in Food Safety Challenge Studies: A Review.

PubMed

Hu, Mengyi; Gurtler, Joshua B

2017-09-01

Nonpathogenic surrogate bacteria are prevalently used in a variety of food challenge studies in place of foodborne pathogens such as Listeria monocytogenes, Salmonella, Escherichia coli O157:H7, and Clostridium botulinum because of safety and sanitary concerns. Surrogate bacteria should have growth characteristics and/or inactivation kinetics similar to those of target pathogens under given conditions in challenge studies. It is of great importance to carefully select and validate potential surrogate bacteria when verifying microbial inactivation processes. A validated surrogate responds similar to the targeted pathogen when tested for inactivation kinetics, growth parameters, or survivability under given conditions in agreement with appropriate statistical analyses. However, a considerable number of food studies involving putative surrogate bacteria lack convincing validation sources or adequate validation processes. Most of the validation information for surrogates in these studies is anecdotal and has been collected from previous publications but may not be sufficient for given conditions in the study at hand. This review is limited to an overview of select studies and discussion of the general criteria and approaches for selecting potential surrogate bacteria under given conditions. The review also includes a list of documented bacterial pathogen surrogates and their corresponding food products and treatments to provide guidance for future studies.

Impact of automated dispensing cabinets on medication selection and preparation error rates in an emergency department: a prospective and direct observational before-and-after study.

PubMed

Fanning, Laura; Jones, Nick; Manias, Elizabeth

2016-04-01

The implementation of automated dispensing cabinets (ADCs) in healthcare facilities appears to be increasing, in particular within Australian hospital emergency departments (EDs). While the investment in ADCs is on the increase, no studies have specifically investigated the impacts of ADCs on medication selection and preparation error rates in EDs. Our aim was to assess the impact of ADCs on medication selection and preparation error rates in an ED of a tertiary teaching hospital. Pre intervention and post intervention study involving direct observations of nurses completing medication selection and preparation activities before and after the implementation of ADCs in the original and new emergency departments within a 377-bed tertiary teaching hospital in Australia. Medication selection and preparation error rates were calculated and compared between these two periods. Secondary end points included the impact on medication error type and severity. A total of 2087 medication selection and preparations were observed among 808 patients pre and post intervention. Implementation of ADCs in the new ED resulted in a 64.7% (1.96% versus 0.69%, respectively, P = 0.017) reduction in medication selection and preparation errors. All medication error types were reduced in the post intervention study period. There was an insignificant impact on medication error severity as all errors detected were categorised as minor. The implementation of ADCs could reduce medication selection and preparation errors and improve medication safety in an ED setting. © 2015 John Wiley & Sons, Ltd.

Intentions of young students to enroll in science courses in the future: An examination of gender differences

NASA Astrophysics Data System (ADS)

Farenga, Stephen J.; Joyce, Beverly A.

1999-01-01

This study examined young students' perceptions of gender-appropriate science courses. The sample consisted of 427 students in grades 4, 5, and 6, between the ages of 9 and 13. Students completed the Course Selection Sheet (CSS) to choose courses for themselves and members of the opposite gender. A psychosocial framework was offered to explain the differential course selection patterns between young boys and girls. The study reveals a strong gender effect pointing toward stereotypical perceptions of selected science courses for oneself (p 0.01). When students selected science courses for the opposite gender, the evidence of gender-role stereotypes was even greater (p < 0.000). Course selection profiles imply that a reciprocal relationship exists in the number and kind of courses selected by girls and boys. A detailed analysis suggests that both boys and girls perceive physical science and technology-related courses as appropriate subjects for boys to study and life sciences as appropriate subjects for girls to study. Surprisingly, students' future science course selections resemble current enrollment data of master's and doctoral candidates. The students' perceptions of science are seen years prior to the actual encounter with the science courses listed on the course selection menu. These findings question the auspiciousness of programs designed to ameliorate gender differences in science during junior or senior high school years. Suggestions for school curriculum development and the importance of informal science experiences were examined.

Compact cancer biomarkers discovery using a swarm intelligence feature selection algorithm.

PubMed

Martinez, Emmanuel; Alvarez, Mario Moises; Trevino, Victor

2010-08-01

Biomarker discovery is a typical application from functional genomics. Due to the large number of genes studied simultaneously in microarray data, feature selection is a key step. Swarm intelligence has emerged as a solution for the feature selection problem. However, swarm intelligence settings for feature selection fail to select small features subsets. We have proposed a swarm intelligence feature selection algorithm based on the initialization and update of only a subset of particles in the swarm. In this study, we tested our algorithm in 11 microarray datasets for brain, leukemia, lung, prostate, and others. We show that the proposed swarm intelligence algorithm successfully increase the classification accuracy and decrease the number of selected features compared to other swarm intelligence methods. Copyright © 2010 Elsevier Ltd. All rights reserved.

[Psychophysiological selection: status and prospects].

PubMed

Gurovskiĭ, N N; Novikov, M A

1981-01-01

The major stages in the development of psychophysiological selection of cosmonauts in the USSR are discussed. The psychophysiological selection was originally based on the data of psychoneurological expertise of the flight personnel and achievements of aviation psychology in the USSR. This was followed by the development of psychophysiological research, using instrumentation and simulation flights. Further complication of flight programs and participation of non-pilot cosmonauts (engineers, scientists) necessitated detailed study of personality properties and application of personality tests. At the present stage in the development of psychophysiological selection great importance is attached to the biorhythmological selection and methods for studying man's capabilities to control his own emotional, behavioral and autonomic reactions as well as environmental parameters. The review also discusses in detail methods of group selection and problems of rational selection of space crews.

Application of random effects to the study of resource selection by animals

USGS Publications Warehouse

Gillies, C.S.; Hebblewhite, M.; Nielsen, S.E.; Krawchuk, M.A.; Aldridge, Cameron L.; Frair, J.L.; Saher, D.J.; Stevens, C.E.; Jerde, C.L.

2006-01-01

1. Resource selection estimated by logistic regression is used increasingly in studies to identify critical resources for animal populations and to predict species occurrence.2. Most frequently, individual animals are monitored and pooled to estimate population-level effects without regard to group or individual-level variation. Pooling assumes that both observations and their errors are independent, and resource selection is constant given individual variation in resource availability.3. Although researchers have identified ways to minimize autocorrelation, variation between individuals caused by differences in selection or available resources, including functional responses in resource selection, have not been well addressed.4. Here we review random-effects models and their application to resource selection modelling to overcome these common limitations. We present a simple case study of an analysis of resource selection by grizzly bears in the foothills of the Canadian Rocky Mountains with and without random effects.5. Both categorical and continuous variables in the grizzly bear model differed in interpretation, both in statistical significance and coefficient sign, depending on how a random effect was included. We used a simulation approach to clarify the application of random effects under three common situations for telemetry studies: (a) discrepancies in sample sizes among individuals; (b) differences among individuals in selection where availability is constant; and (c) differences in availability with and without a functional response in resource selection.6. We found that random intercepts accounted for unbalanced sample designs, and models with random intercepts and coefficients improved model fit given the variation in selection among individuals and functional responses in selection. Our empirical example and simulations demonstrate how including random effects in resource selection models can aid interpretation and address difficult assumptions limiting their generality. This approach will allow researchers to appropriately estimate marginal (population) and conditional (individual) responses, and account for complex grouping, unbalanced sample designs and autocorrelation.

Application of random effects to the study of resource selection by animals.

PubMed

Gillies, Cameron S; Hebblewhite, Mark; Nielsen, Scott E; Krawchuk, Meg A; Aldridge, Cameron L; Frair, Jacqueline L; Saher, D Joanne; Stevens, Cameron E; Jerde, Christopher L

2006-07-01

1. Resource selection estimated by logistic regression is used increasingly in studies to identify critical resources for animal populations and to predict species occurrence. 2. Most frequently, individual animals are monitored and pooled to estimate population-level effects without regard to group or individual-level variation. Pooling assumes that both observations and their errors are independent, and resource selection is constant given individual variation in resource availability. 3. Although researchers have identified ways to minimize autocorrelation, variation between individuals caused by differences in selection or available resources, including functional responses in resource selection, have not been well addressed. 4. Here we review random-effects models and their application to resource selection modelling to overcome these common limitations. We present a simple case study of an analysis of resource selection by grizzly bears in the foothills of the Canadian Rocky Mountains with and without random effects. 5. Both categorical and continuous variables in the grizzly bear model differed in interpretation, both in statistical significance and coefficient sign, depending on how a random effect was included. We used a simulation approach to clarify the application of random effects under three common situations for telemetry studies: (a) discrepancies in sample sizes among individuals; (b) differences among individuals in selection where availability is constant; and (c) differences in availability with and without a functional response in resource selection. 6. We found that random intercepts accounted for unbalanced sample designs, and models with random intercepts and coefficients improved model fit given the variation in selection among individuals and functional responses in selection. Our empirical example and simulations demonstrate how including random effects in resource selection models can aid interpretation and address difficult assumptions limiting their generality. This approach will allow researchers to appropriately estimate marginal (population) and conditional (individual) responses, and account for complex grouping, unbalanced sample designs and autocorrelation.

Sensitivity of landscape resistance estimates based on point selection functions to scale and behavioral state: Pumas as a case study

Treesearch

Katherine A. Zeller; Kevin McGarigal; Paul Beier; Samuel A. Cushman; T. Winston Vickers; Walter M. Boyce

2014-01-01

Estimating landscape resistance to animal movement is the foundation for connectivity modeling, and resource selection functions based on point data are commonly used to empirically estimate resistance. In this study, we used GPS data points acquired at 5-min intervals from radiocollared pumas in southern California to model context-dependent point selection...

Selection, Evaluation, and Modification of a Standard Operating Procedure as a Mechanism for Introducing an Undergraduate Student to Chemical Research: A Case Study

ERIC Educational Resources Information Center

Claycomb, Gregory D.; Venable, Frances A.

2015-01-01

In an effort to broaden the selection of research opportunities available to a student registered in a one-semester, upper-level independent study course at a primarily undergraduate institution (PUI), a highly motivated student was asked to select, evaluate, and modify a standard operating procedure (SOP). The student gained valuable experience…

A Comparative Study of Students' Access to and Utilization of Learning Resources in Selected Public and Private Universities in Southwest, Nigeria

ERIC Educational Resources Information Center

Lawal, B. O.; Viatonu, Olumuyiwa

2017-01-01

The study investigated students' access to and utilization of some learning resources in selected public and private universities in southwest Nigeria. Stratified random sampling technique was used to select 585 (295 public and 290 private) students from 12 (six public and six private) universities in southwest Nigeria. Two instruments--Cost and…

The Effect of Using a Proposed Teaching Strategy Based on the Selective Thinking on Students' Acquisition Concepts in Mathematics

ERIC Educational Resources Information Center

Qudah, Ahmad Hassan

2016-01-01

This study aimed at identify the effect of using a proposed teaching strategy based on the selective thinking in acquire mathematical concepts by Classroom Teacher Students at Al- al- Bayt University, The sample of the study consisted of (74) students, equally distributed into a control group and an experimental group. The selective thinking…

Stimulus selectivity of drug purchase tasks: A preliminary study evaluating alcohol and cigarette demand.

PubMed

Strickland, Justin C; Stoops, William W

2017-06-01

The use of drug purchase tasks to measure drug demand in human behavioral pharmacology and addiction research has proliferated in recent years. Few studies have systematically evaluated the stimulus selectivity of drug purchase tasks to demonstrate that demand metrics are specific to valuation of or demand for the commodity under study. Stimulus selectivity is broadly defined for this purpose as a condition under which a specific stimulus input or target (e.g., alcohol, cigarettes) is the primary determinant of behavior (e.g., demand). The overall goal of the present study was to evaluate the stimulus selectivity of drug purchase tasks. Participants were sampled from the Amazon.com's crowdsourcing platform Mechanical Turk. Participants completed either alcohol and soda purchase tasks (Experiment 1; N = 139) or cigarette and chocolate purchase tasks (Experiment 2; N = 46), and demand metrics were compared to self-reported use behaviors. Demand metrics for alcohol and soda were closely associated with commodity-similar (e.g., alcohol demand and weekly alcohol use) but not commodity-different (e.g., alcohol demand and weekly soda use) variables. A similar pattern was observed for cigarette and chocolate demand, but selectivity was not as consistent as for alcohol and soda. Collectively, we observed robust selectivity for alcohol and soda purchase tasks and modest selectivity for cigarette and chocolate purchase tasks. These preliminary outcomes suggest that demand metrics adequately reflect the specific commodity under study and support the continued use of purchase tasks in substance use research. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

The role of chemoprevention by selective cyclooxygenase-2 inhibitors in colorectal cancer patients - a population-based study

PubMed Central

2012-01-01

Background There are limited population-based studies focusing on the chemopreventive effects of selective cyclooxygenase-2 (COX-2) inhibitors against colorectal cancer. The purpose of this study is to assess the trends and dose–response effects of various medication possession ratios (MPR) of selective COX-2 inhibitor used for chemoprevention of colorectal cancer. Methods A population-based case–control study was conducted using the Taiwan Health Insurance Research Database (NHIRD). The study comprised 21,460 colorectal cancer patients and 79,331 controls. The conditional logistic regression was applied to estimate the odds ratios (ORs) for COX-2 inhibitors used for several durations (5 years, 3 years, 1 year, 6 months and 3 months) prior to the index date. Results In patients receiving selective COX-2 inhibitors, the OR was 0.51 (95% CI=0.29~0.90, p=0.021) for an estimated 5-year period in developing colorectal cancer. ORs showing significant protection effects were found in 10% of MPRs for 5-year, 3-year, and 1-year usage. Risk reduction against colorectal cancer by selective COX-2 inhibitors was observed as early as 6 months after usage. Conclusion Our results indicate that selective COX-2 inhibitors may reduce the development of colorectal cancer by at least 10% based on the MPRs evaluated. Given the limited number of clinical reports from general populations, our results add to the knowledge of chemopreventive effects of selective COX-2 inhibitors against cancer in individuals at no increased risk of colorectal cancer. PMID:23217168

Design of a mercury Propellant Storage and Distribution assembly

NASA Technical Reports Server (NTRS)

Holcomb, L. B.; Womack, J. R.

1973-01-01

A study has been conducted of a Propellant Storage and Distribution (PSD) assembly for a solar electric propulsion (SEP) thrust subsystem. As a result of the trade-off study an elastomeric diaphragm propellant tank with nitrogen blowdown pressurization was the method selected for propellant expulsion. This study included the following propellant management devices: surface tension, metallic bellows, and metallic and elastomeric diaphragms. Pressurant supply concepts investigated were blowdown, externally pressure regulated, vaporizing Freon 113, and heated CO2/Zeolite. The configuration selected consists of a single propellant tank, a single main propellant latching-solenoid valve, and individual thruster latching-solenoid valves. Stainless steel was the selected tankage material and AF-E-332 was the selected diaphragm material. The PSD design characteristics and interfaces are summarized.

A Relational Study of Principal Leadership Styles, Faculty Morale, and Faculty Job Satisfaction at Selected Elementary Schools

ERIC Educational Resources Information Center

Ramsey Hearn, Dawn Vyola

2013-01-01

The purpose of this study was to determine if a significant relationship existed between principal leadership styles, faculty morale, and faculty job satisfaction at selected elementary schools. Specifically, the study examined if the perception teachers had of their principals. leadership styles had an impact on faculty morale and faculty job…

A Long-Term Outcome Study of Selective Mutism in Childhood

ERIC Educational Resources Information Center

Steinhausen, Hans-Christoph; Wachter, Miriam; Laimbock, Karin; Metzke, Christa Winkler

2006-01-01

Objective: Controlled study of the long-term outcome of selective mutism (SM) in childhood. Method: A sample of 33 young adults with SM in childhood and two age- and gender-matched comparison groups were studied. The latter comprised 26 young adults with anxiety disorders in childhood (ANX) and 30 young adults with no psychiatric disorders during…

The Influence of Birth Country on Selection of Conference Destination--Employing Natural Language Processing

ERIC Educational Resources Information Center

Davidovitch, Nitza; Eckhaus, Eyal

2018-01-01

This study deals with immigrant scientists integrated in academia in Israel. Studies on the subject indicate the contribution of immigrant scientists to research. The current study focuses on the influence of scientists' birth country on selecting destinations for academic conferences, as well as on the influence of one's native language on the…

An Evaluation of Selected NASA Scientific and Technical Information Products: Results of a Pilot Study.

ERIC Educational Resources Information Center

Pinelli, Thomas E.; Glassman, Myron

A pilot study was conducted to evaluate selected NASA (National Aeronautics and Space Administration) scientific and technical information (STI) products. The study, which utilized survey research in the form of a self-administered mail questionnaire, had a two-fold purpose--to gather baseline data on the use and perceived usefulness of selected…

Selective Attention in Web Forms: An Exploratory Case Study with Older People

ERIC Educational Resources Information Center

Sayago, Sergio; Guijarro, Jose-Maria; Blat, Josep

2012-01-01

This article reports on an exploratory study aimed to identify which ways of marking required and optional fields help older people fill in web forms correctly. Drawing on a pilot study and selective attention research in ageing, modified versions of widely used forms were created, in which standard asterisks were replaced with one of three…

The Role of Motivation, Perceived Constraints, and Constraint Negotiation Strategies in Students' Internship Selection Experience

ERIC Educational Resources Information Center

Batty, Kimberly A.

2011-01-01

The purpose of this study was to document the factors (i.e., motivation and perceived constraints) and processes (i.e., constraint negotiation) that influence students' selection of and satisfaction with their internship choice. The study was conducted using a quantitative approach, which included a focus group, a pilot study, and a…

The Predictive Validity of the University Student Selection Examination

ERIC Educational Resources Information Center

Karakaya, Ismail; Tavsancil, Ezel

2008-01-01

The main purpose of this study is to investigate the predictive validity of the 2003 University Student Selection Examination (OSS). For this purpose, freshman grade point average (FGPA) in higher education was predicted by raw scores, standard scores, and placement scores (YEP). This study has been conducted on a research group. In this study,…

Threat and Selective Exposure: The Moderating Role of Threat and Decision Context on Confirmatory Information Search after Decisions

ERIC Educational Resources Information Center

Fischer, Peter; Kastenmuller, Andreas; Greitemeyer, Tobias; Fischer, Julia; Frey, Dieter; Crelley, David

2011-01-01

Previous studies on the impact of perceived threat on confirmatory information search (selective exposure) in the context of decision making have yielded mixed results. Some studies have suggested that confirmatory information search is reduced, yet others have found contradictory effects. The present series of 5 studies consistently found that…

Critical Pedagogy and Materials Development: Content Selection and Gradation

ERIC Educational Resources Information Center

Rahimi, Ali; Kushki, Ali; Ansaripour, Ehsan; Maki, Ardeshir

2015-01-01

The study aimed at presenting how materials developers can design materials based on the tenets of Critical Pedagogy (CP). Having reviewed the literature on CP, the present study attempted to propose ideas for the selection and gradation phase of Materials Development in line with the tenets of CP. The distinguishing feature of the study was to…

A Study of Selected Developing Colleges and Universities. Case Study II: St. Mary's Junior College, Minneapolis, Minnesota.

ERIC Educational Resources Information Center

St. John, Edward P.

As part of a study of selected developing colleges and universities funded in the Advanced Institutional Development Program (AIDP), this report focuses on St. Mary's Junior College (SMJC), a Roman Catholic, two-year college specializing exclusively in health, health-related and human service fields. The report considers SMJC's state of…

Making Their Way: An Interpretive Case Study of Male First-Generation Students Attending a Highly Selective Liberal Arts College

ERIC Educational Resources Information Center

Peltz, Mark R.

2013-01-01

This qualitative study focused on the experiences of eight male first-generation college students attending Kenmont College (pseudonym), a highly selective, residential liberal arts college located in the Midwestern United States. While first-generation college students have been studied in various contexts, very little is known about what…

A Five Year Study of Selected Demographics of Middlesex Community College Graduates: 1985-1989.

ERIC Educational Resources Information Center

Coggins, John H.; Muzeroll, Terry

This analysis of selected demographic statistics of Middlesex Community College (MxCC) graduates is intended for future academic advising, curriculum planning, and decision making. This demographic profile is comprised of data from studies published between 1985 and 1989. The study focuses on fundamental demographic indicators, such as sex, age,…

Are All Colleges Equally Equalizing? How Institutional Selectivity Impacts Socioeconomic Disparities in Graduates' Labor Outcomes

ERIC Educational Resources Information Center

Giani, Matt S.

2016-01-01

The purpose of this study is to examine the extent to which the magnitude of disparities in the labor market outcomes of college graduates stemming from socioeconomic background varies according to institutional selectivity. The data used for the study are drawn from the National Center for Education Statistics' Education Longitudinal Study of…

Evaluating candidate reactions to selection practices using organisational justice theory.

PubMed

Patterson, Fiona; Zibarras, Lara; Carr, Victoria; Irish, Bill; Gregory, Simon

2011-03-01

This study aimed to examine candidate reactions to selection practices in postgraduate medical training using organisational justice theory. We carried out three independent cross-sectional studies using samples from three consecutive annual recruitment rounds. Data were gathered from candidates applying for entry into UK general practice (GP) training during 2007, 2008 and 2009. Participants completed an evaluation questionnaire immediately after the short-listing stage and after the selection centre (interview) stage. Participants were doctors applying for GP training in the UK. Main outcome measures were participants' evaluations of the selection methods and perceptions of the overall fairness of each selection stage (short-listing and selection centre). A total of 23,855 evaluation questionnaires were completed (6893 in 2007, 10,497 in 2008 and 6465 in 2009). Absolute levels of perceptions of fairness of all the selection methods at both the short-listing and selection centre stages were consistently high over the 3years. Similarly, all selection methods were considered to be job-related by candidates. However, in general, candidates considered the selection centre stage to be significantly fairer than the short-listing stage. Of all the selection methods, the simulated patient consultation completed at the selection centre stage was rated as the most job-relevant. This is the first study to use a model of organisational justice theory to evaluate candidate reactions during selection into postgraduate specialty training. The high-fidelity selection methods are consistently viewed as more job-relevant and fairer by candidates. This has important implications for the design of recruitment systems for all specialties and, potentially, for medical school admissions. Using this approach, recruiters can systematically compare perceptions of the fairness and job relevance of various selection methods. © Blackwell Publishing Ltd 2011.

Situation selection is a particularly effective emotion regulation strategy for people who need help regulating their emotions.

PubMed

Webb, Thomas L; Lindquist, Kristen A; Jones, Katelyn; Avishai, Aya; Sheeran, Paschal

2018-03-01

Situation selection involves choosing situations based on their likely emotional impact and may be less cognitively taxing or challenging to implement compared to other strategies for regulating emotion, which require people to regulate their emotions "in the moment"; we thus predicted that individuals who chronically experience intense emotions or who are not particularly competent at employing other emotion regulation strategies would be especially likely to benefit from situation selection. Consistent with this idea, we found that the use of situation selection interacted with individual differences in emotional reactivity and competence at emotion regulation to predict emotional outcomes in both a correlational (Study 1; N = 301) and an experimental field study (Study 2; N = 125). Taken together, the findings suggest that situation selection is an effective strategy for regulating emotions, especially for individuals who otherwise struggle to do so.

Nursing Outcomes for Patients with Risk of Perioperative Positioning Injury.

PubMed

de Lima, Luciana Bjorklund; E Cardozo, Michelle Cardoso; Bernardes, Daniela de Souza; Rabelo-Silva, Eneida Rejane

2018-04-16

To select and refine the outcomes and indicators of Nursing Outcomes Classification for the diagnosis of risk for perioperative positioning injury. Validation study on expert consensus and refinement through pilot study. Eight outcomes and 35 indicators were selected in consensus. After clinical testing was performed, in which 10 patients were assessed at five different times. Eight outcomes and 33 indicators remained in the protocol. This study made it possible to select the most relevant outcomes and indicators to be measured for this diagnosis in clinical practice. Validation studies by consensus and clinical testing are important to promote the accuracy, creating opportunities to legitimize, and improve the concepts of taxonomies. © 2018 NANDA International, Inc.

Do physical maturity and birth date predict talent in male youth ice hockey players?

PubMed

Sherar, Lauren B; Baxter-Jones, Adam D G; Faulkner, Robert A; Russell, Keith W

2007-06-01

The aim of this study was to examine the relationships among biological maturity, physical size, relative age (i.e. birth date), and selection into a male Canadian provincial age-banded ice hockey team. In 2003, 619 male ice hockey players aged 14-15 years attended Saskatchewan provincial team selection camps, 281 of whom participated in the present study. Data from 93 age-matched controls were obtained from the Saskatchewan Pediatric Bone Mineral Accrual Study (1991-1997). During the initial selection camps, birth dates, heights, sitting heights, and body masses were recorded. Age at peak height velocity, an indicator of biological maturity, was determined in the controls and predicted in the ice hockey players. Data were analysed using one-way analysis of variance, logistic regression, and a Kolmogorov-Smirnov test. The ice hockey players selected for the final team were taller, heavier, and more mature (P < 0.05) than both the unselected players and the age-matched controls. Furthermore, age at peak height velocity predicted (P < 0.05) being selected at the first and second selection camps. The birth dates of those players selected for the team were positively skewed, with the majority of those selected being born in the months January to June. In conclusion, team selectors appear to preferentially select early maturing male ice hockey players who have birth dates early in the selection year.

An integrated analysis of phenotypic selection on insect body size and development time.

PubMed

Eck, Daniel J; Shaw, Ruth G; Geyer, Charles J; Kingsolver, Joel G

2015-09-01

Most studies of phenotypic selection do not estimate selection or fitness surfaces for multiple components of fitness within a unified statistical framework. This makes it difficult or impossible to assess how selection operates on traits through variation in multiple components of fitness. We describe a new generation of aster models that can evaluate phenotypic selection by accounting for timing of life-history transitions and their effect on population growth rate, in addition to survival and reproductive output. We use this approach to estimate selection on body size and development time for a field population of the herbivorous insect, Manduca sexta (Lepidoptera: Sphingidae). Estimated fitness surfaces revealed strong and significant directional selection favoring both larger adult size (via effects on egg counts) and more rapid rates of early larval development (via effects on larval survival). Incorporating the timing of reproduction and its influence on population growth rate into the analysis resulted in larger values for size in early larval development at which fitness is maximized, and weaker selection on size in early larval development. These results illustrate how the interplay of different components of fitness can influence selection on size and development time. This integrated modeling framework can be readily applied to studies of phenotypic selection via multiple fitness components in other systems. © 2015 The Author(s). Evolution © 2015 The Society for the Study of Evolution.

Economic indicators selection for crime rates forecasting using cooperative feature selection

NASA Astrophysics Data System (ADS)

Alwee, Razana; Shamsuddin, Siti Mariyam Hj; Salleh Sallehuddin, Roselina

2013-04-01

Features selection in multivariate forecasting model is very important to ensure that the model is accurate. The purpose of this study is to apply the Cooperative Feature Selection method for features selection. The features are economic indicators that will be used in crime rate forecasting model. The Cooperative Feature Selection combines grey relational analysis and artificial neural network to establish a cooperative model that can rank and select the significant economic indicators. Grey relational analysis is used to select the best data series to represent each economic indicator and is also used to rank the economic indicators according to its importance to the crime rate. After that, the artificial neural network is used to select the significant economic indicators for forecasting the crime rates. In this study, we used economic indicators of unemployment rate, consumer price index, gross domestic product and consumer sentiment index, as well as data rates of property crime and violent crime for the United States. Levenberg-Marquardt neural network is used in this study. From our experiments, we found that consumer price index is an important economic indicator that has a significant influence on the violent crime rate. While for property crime rate, the gross domestic product, unemployment rate and consumer price index are the influential economic indicators. The Cooperative Feature Selection is also found to produce smaller errors as compared to Multiple Linear Regression in forecasting property and violent crime rates.

Pharmacogenetic Selection of Volunteers Increases Stringency of Bioequivalence Studies; The Case of Clopidogrel

PubMed Central

Garcés-Eisele, J.; Ruiz-Argüelles, A.; Estrada-Marín, Larisa; Reyes-Núñez, Virginia; Vázquez-Pérez, R.; Guzmán-García, Olga; Coutiño-Medina, R.; Acosta-Sandria, Leticia; Cedillo-Carvallo, Beatriz

2014-01-01

Clinical response to clopidogrel varies widely due to under-dosing, drug interactions and intrinsic interindividual differences resulting from genetic polymorphisms. Cytochrome P450-2C19 is the principal enzyme involved in the activation of the prodrug and loss-of-function alleles have been described. Upon expiration of the pharmaceutical patent of clopidogrel, generic manufacturers have started to subject interchangeable formulations to bioequivalence studies. The purpose of the current investigation was to study the effect of selection of volunteers homozygous for the CYP2C19*1 haplotype on the bioavailability of clopidogrel. A regular 2×2 bioequivalence study between two formulations of clopidogrel was performed in volunteers selected and unselected for relevant CYP2C19 haplotypes for the Mexican population. It was found that selection of volunteers homozygous for the CYP2C19*1 haplotype, increased the stringency of bioequivalence statistics and resulted in bioinequivalence of a generic clopidogrel compound that otherwise proved equivalent when tested in an open unselected population. Augmentation of bioequivalence strictness is expected to result from pharmacogenetic selection of volunteers. PMID:25284925

Selecting the most appropriate time points to profile in high-throughput studies

PubMed Central

Kleyman, Michael; Sefer, Emre; Nicola, Teodora; Espinoza, Celia; Chhabra, Divya; Hagood, James S; Kaminski, Naftali; Ambalavanan, Namasivayam; Bar-Joseph, Ziv

2017-01-01

Biological systems are increasingly being studied by high throughput profiling of molecular data over time. Determining the set of time points to sample in studies that profile several different types of molecular data is still challenging. Here we present the Time Point Selection (TPS) method that solves this combinatorial problem in a principled and practical way. TPS utilizes expression data from a small set of genes sampled at a high rate. As we show by applying TPS to study mouse lung development, the points selected by TPS can be used to reconstruct an accurate representation for the expression values of the non selected points. Further, even though the selection is only based on gene expression, these points are also appropriate for representing a much larger set of protein, miRNA and DNA methylation changes over time. TPS can thus serve as a key design strategy for high throughput time series experiments. Supporting Website: www.sb.cs.cmu.edu/TPS DOI: http://dx.doi.org/10.7554/eLife.18541.001 PMID:28124972

Constrained evolution of the sex comb in Drosophila simulans.

PubMed

Maraqa, M S; Griffin, R; Sharma, M D; Wilson, A J; Hunt, J; Hosken, D J; House, C M

2017-02-01

Male fitness is dependent on sexual traits that influence mate acquisition (precopulatory sexual selection) and paternity (post-copulatory sexual selection), and although many studies have documented the form of selection in one or the other of these arenas, fewer have done it for both. Nonetheless, it appears that the dominant form of sexual selection is directional, although theoretically, populations should converge on peaks in the fitness surface, where selection is stabilizing. Many factors, however, can prevent populations from reaching adaptive peaks. Genetic constraints can be important if they prevent the development of highest fitness phenotypes, as can the direction of selection if it reverses across episodes of selection. In this study, we examine the evidence that these processes influence the evolution of the multivariate sex comb morphology of male Drosophila simulans. To do this, we conduct a quantitative genetic study together with a multivariate selection analysis to infer how the genetic architecture and selection interact. We find abundant genetic variance and covariance in elements of the sex comb. However, there was little evidence for directional selection in either arena. Significant nonlinear selection was detected prior to copulation when males were mated to nonvirgin females, and post-copulation during sperm offence (again with males mated to nonvirgins). Thus, contrary to our predictions, the evolution of the D. simulans sex comb is limited neither by genetic constraints nor by antagonistic selection between pre- and post-copulatory arenas, but nonlinear selection on the multivariate phenotype may prevent sex combs from evolving to reach some fitness maximizing optima. © 2016 The Authors. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

Using phenotypic manipulations to study multivariate selection of floral trait associations

PubMed Central

Campbell, Diane R.

2009-01-01

Background A basic theme in the study of plant–pollinator interactions is that pollinators select not just for single floral traits, but for associations of traits. Responses of pollinators to sets of traits are inherent in the idea of pollinator syndromes. In its most extreme form, selection on a suite of traits can take the form of correlational selection, in which a response to one trait depends on the value of another, thereby favouring floral integration. Despite the importance of selection for combinations of traits in the evolution of flowers, evidence is relatively sparse and relies mostly on observational approaches. Scope Here, methods for measuring selection on multivariate suites of floral traits are presented, and the studies to date are reviewed. It is argued that phenotypic manipulations present a powerful, but rarely used, approach to teasing apart the separate and combined effects of particular traits. The approach is illustrated with data from studies of alpine plants in Colorado and New Zealand, and recommendations are made about several features of the design of such experiments. Conclusions Phenotypic manipulations of two or more traits in combination provide a direct way of testing for selection of floral trait associations. Such experiments will be particularly valuable if rooted in hypotheses about differences between types of pollinators and tied to a proposed evolutionary history. PMID:19218579

Transcriptome sequencing of Eucalyptus camaldulensis seedlings subjected to water stress reveals functional single nucleotide polymorphisms and genes under selection

PubMed Central

2012-01-01

Background Water stress limits plant survival and production in many parts of the world. Identification of genes and alleles responding to water stress conditions is important in breeding plants better adapted to drought. Currently there are no studies examining the transcriptome wide gene and allelic expression patterns under water stress conditions. We used RNA sequencing (RNA-seq) to identify the candidate genes and alleles and to explore the evolutionary signatures of selection. Results We studied the effect of water stress on gene expression in Eucalyptus camaldulensis seedlings derived from three natural populations. We used reference-guided transcriptome mapping to study gene expression. Several genes showed differential expression between control and stress conditions. Gene ontology (GO) enrichment tests revealed up-regulation of 140 stress-related gene categories and down-regulation of 35 metabolic and cell wall organisation gene categories. More than 190,000 single nucleotide polymorphisms (SNPs) were detected and 2737 of these showed differential allelic expression. Allelic expression of 52% of these variants was correlated with differential gene expression. Signatures of selection patterns were studied by estimating the proportion of nonsynonymous to synonymous substitution rates (Ka/Ks). The average Ka/Ks ratio among the 13,719 genes was 0.39 indicating that most of the genes are under purifying selection. Among the positively selected genes (Ka/Ks > 1.5) apoptosis and cell death categories were enriched. Of the 287 positively selected genes, ninety genes showed differential expression and 27 SNPs from 17 positively selected genes showed differential allelic expression between treatments. Conclusions Correlation of allelic expression of several SNPs with total gene expression indicates that these variants may be the cis-acting variants or in linkage disequilibrium with such variants. Enrichment of apoptosis and cell death gene categories among the positively selected genes reveals the past selection pressures experienced by the populations used in this study. PMID:22853646

Theoretical rationale for music selection in oncology intervention research: an integrative review.

PubMed

Burns, Debra S

2012-01-01

Music-based interventions have helped patients with cancer improve their quality of life, decrease treatment related distress, and manage pain. However, quantitative findings from music intervention studies are inconsistent. The purpose of this review was to explore the theoretical underpinnings for the selection of the music stimuli used to influence targeted outcomes. It was hypothesized that disparate findings were due in part to the atheoretical nature of music selection and the resulting diversity in music stimuli between and within studies. A systematic research synthesis including a comprehensive database and reference list search resulted in 22 studies. Included studies were compiled into two tables cataloging intervention theory, intervention content, and outcomes. A majority of studies did not provide a rationale or intervention theory for the delivery of music or choice of outcomes. Recorded music was the most common delivery method, but the specific music was rarely included within the report. Only two studies that included a theoretical framework reported null results on at least some of the outcomes. Null results are partially explained by an incomplete or mismatch in intervention theory and music selection and delivery. While the inclusion of an intervention theory does not guarantee positive results, including a theoretical rationale for the use of music, particular therapeutic processes or mechanisms, and the specifics of how music is selected and delivered increases scientific rigor and the probability of clinical translation.

Working memory and the strategic control of attention in older and younger adults.

PubMed

Hayes, Melissa G; Kelly, Andrew J; Smith, Anderson D

2013-03-01

The objective of this study was to investigate the effects of aging on the strategic control of attention and the extent to which this relationship is mediated by working memory capacity (WMC). This study also sought to investigate boundary conditions wherein age differences in selectivity may occur. Across 2 studies, the value-directed remembering task used by Castel and colleagues (Castel, A. D., Balota, D. A., & McCabe, D. P. (2009). Memory efficiency and the strategic control of attention at encoding: Impairments of value-directed remembering in Alzheimer's Disease. Neuropsychology, 23, 297-306) was modified to include value-directed forgetting. Study 2 incorporated valence as an additional task demand, and age differences were predicted in both studies due to increased demands of controlled processing. Automated operation span and Stroop span were included as working memory measures, and working memory was predicted to mediate performance. Results confirmed these predictions, as older adults were less efficient in maximizing selectivity scores when high demands were placed on selectivity processes, and working memory was found to mediate performance on this task. When list length was increased from previous studies and participants were required to actively forget negative-value words, older adults were not able to selectively encode high-value information to the same degree as younger adults. Furthermore, WMC appears to support the ability to selectively encode information.

A mitochondria-selective near-infrared-emitting fluorescent dye for cellular imaging studies.

PubMed

Choi, Peter; Noguchi, Katsuya; Ishiyama, Munetaka; Denny, William A; Jose, Jiney

2018-05-03

This communication details the synthesis, evaluation of photophysical properties, and cellular imaging studies of cyanine chromophore based fluorescent dye 1 as a selective imaging agent for mitochondria. Copyright © 2018 Elsevier Ltd. All rights reserved.

The Value in Rushing: Memory and Selectivity when Short on Time

PubMed Central

Middlebrooks, Catherine D.; Murayama, Kou; Castel, Alan D.

2016-01-01

While being short on time can certainly limit what one remembers, are there always such costs? The current study investigates the impact of time constraints on selective memory and the self-regulated study of valuable information. Participants studied lists of words ranging in value from 1-10 points, with the goal being to maximize their score during recall. Half of the participants studied these words at a constant presentation rate of either 1 or 5 seconds. The other half of participants studied under both rates, either fast (1sec) during the first several lists and then slow (5sec) during later lists, or vice versa. Study was then self-paced during a final segment of lists for all participants to determine how people regulate their study time after experiencing different presentation rates during study. While participants recalled more words overall when studying at a 5-second rate, there were no significant differences in terms of value-based recall, with all participants demonstrating better recall for higher-valued words and similar patterns of selectivity, regardless of study time or prior timing experience. Self-paced study was also value-based, with participants spending more time studying high-value words than low-value. Thus, while being short on time may have impaired memory overall, participants’ attention to item value during study was not differentially impacted by the fast and slow timing rates. Overall, these findings offer further insight regarding the influence that timing schedules and task experience have on how people selectively focus on valuable information. PMID:27305652

A Pharmacometric Approach to Substitute for a Conventional Dose-Finding Study in Rare Diseases: Example of Phase III Dose Selection for Emicizumab in Hemophilia A.

PubMed

Yoneyama, Koichiro; Schmitt, Christophe; Kotani, Naoki; Levy, Gallia G; Kasai, Ryu; Iida, Satofumi; Shima, Midori; Kawanishi, Takehiko

2017-12-06

Emicizumab (ACE910) is a bispecific antibody mimicking the cofactor function of activated coagulation factor VIII. In phase I-I/II studies, emicizumab reduced the bleeding frequency in patients with severe hemophilia A, regardless of the presence of factor VIII inhibitors, at once-weekly subcutaneous doses of 0.3, 1, and 3 mg/kg. Using the phase I-I/II study data, population pharmacokinetic and repeated time-to-event (RTTE) modeling were performed to quantitatively characterize the relationship between the pharmacokinetics of emicizumab and reduction in bleeding frequency. Simulations were then performed to identify the minimal exposure expected to achieve zero bleeding events for 1 year in at least 50% of patients and to select the dosing regimens to be tested in phase III studies. The RTTE model adequately predicted the bleeding onset over time as a function of plasma emicizumab concentration. Simulations suggested that plasma emicizumab concentrations of ≥  45 μg/mL should result in zero bleeding events for 1 year in at least 50% of patients. This efficacious exposure provided the basis for selecting previously untested dosing regimens of 1.5 mg/kg once weekly, 3 mg/kg every 2 weeks, and 6 mg/kg every 4 weeks for phase III studies. A pharmacometric approach guided the phase III dose selection of emicizumab in hemophilia A, without conducting a conventional dose-finding study. Phase III studies with the selected dosing regimens are currently ongoing. This case study indicates that a pharmacometric approach can substitute for a conventional dose-finding study in rare diseases and will streamline the drug development process.

Quality and methodological challenges in Internet-based mental health trials.

PubMed

Ye, Xibiao; Bapuji, Sunita Bayyavarapu; Winters, Shannon; Metge, Colleen; Raynard, Mellissa

2014-08-01

To review the quality of Internet-based mental health intervention studies and their methodological challenges. We searched multiple literature databases to identify relevant studies according to the Population, Interventions, Comparators, Outcomes, and Study Design framework. Two reviewers independently assessed selection bias, allocation bias, confounding bias, blinding, data collection methods, and withdrawals/dropouts, using the Quality Assessment Tool for Quantitative Studies. We rated each component as strong, moderate, or weak and assigned a global rating (strong, moderate, or weak) to each study. We discussed methodological issues related to the study quality. Of 122 studies included, 31 (25%), 44 (36%), and 47 (39%) were rated strong, moderate, and weak, respectively. Only five studies were rated strong for all of the six quality components (three of them were published by the same group). Lack of blinding, selection bias, and low adherence were the top three challenges in Internet-based mental health intervention studies. The overall quality of Internet-based mental health intervention needs to improve. In particular, studies need to improve sample selection, intervention allocation, and blinding.

It Takes Three: Selection, Influence, and De-Selection Processes of Depression in Adolescent Friendship Networks

ERIC Educational Resources Information Center

Van Zalk, Maarten Herman Walter; Kerr, Margaret; Branje, Susan J. T.; Stattin, Hakan; Meeus, Wim H. J.

2010-01-01

The authors of this study tested a selection-influence-de-selection model of depression. This model explains friendship influence processes (i.e., friends' depressive symptoms increase adolescents' depressive symptoms) while controlling for two processes: friendship selection (i.e., selection of friends with similar levels of depressive symptoms)…

Opportunity for natural selection among five population groups of Manipur, North East India.

PubMed

Asghar, M; Meitei, S Y; Luxmi, Y; Achoubi, N; Meitei, K S; Murry, B; Sachdeva, M P; Saraswathy, K N

2014-01-01

Opportunity for natural selection among five population groups of Manipur in comparison with other North East Indian population has been studied. Crow's index as well as Johnston and Kensinger's index for natural selection were calculated based on differential fertility and mortality. The mortality component was found to be lower compared to fertility component in all the populations which may attribute to comparatively improved and easily accessible health care facilities. However, different selection pressures, artificial and natural, seem to be influencing the selection intensity through induced abortion and spontaneous abortion among the two non-tribal migrant groups: Bamon and Muslims, respectively. This study highlights the probable interaction of artificial and natural selection in determining the evolutionary fate of any population group.

The Missing Response to Selection in the Wild.

PubMed

Pujol, Benoit; Blanchet, Simon; Charmantier, Anne; Danchin, Etienne; Facon, Benoit; Marrot, Pascal; Roux, Fabrice; Scotti, Ivan; Teplitsky, Céline; Thomson, Caroline E; Winney, Isabel

2018-05-01

Although there are many examples of contemporary directional selection, evidence for responses to selection that match predictions are often missing in quantitative genetic studies of wild populations. This is despite the presence of genetic variation and selection pressures - theoretical prerequisites for the response to selection. This conundrum can be explained by statistical issues with accurate parameter estimation, and by biological mechanisms that interfere with the response to selection. These biological mechanisms can accelerate or constrain this response. These mechanisms are generally studied independently but might act simultaneously. We therefore integrated these mechanisms to explore their potential combined effect. This has implications for explaining the apparent evolutionary stasis of wild populations and the conservation of wildlife. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Frequentist Model Averaging in Structural Equation Modelling.

PubMed

Jin, Shaobo; Ankargren, Sebastian

2018-06-04

Model selection from a set of candidate models plays an important role in many structural equation modelling applications. However, traditional model selection methods introduce extra randomness that is not accounted for by post-model selection inference. In the current study, we propose a model averaging technique within the frequentist statistical framework. Instead of selecting an optimal model, the contributions of all candidate models are acknowledged. Valid confidence intervals and a [Formula: see text] test statistic are proposed. A simulation study shows that the proposed method is able to produce a robust mean-squared error, a better coverage probability, and a better goodness-of-fit test compared to model selection. It is an interesting compromise between model selection and the full model.

A Study of the Effects of Business Training on the Attitude towards Major Selection of Secondary Level Male Students in Iran

ERIC Educational Resources Information Center

Samiee, Fateme; Sadeghian, Zahra; Akrami, Nahid; Kiani, Mehdi Keikhosro; Golkian, Mina

2015-01-01

The present study aimed to study the effect of business education on the attitudes of the secondary school male student towards major selection. The population of the study were all male secondary students in Isfahan in the year 2013/2015. The sample was a group of 44 students were placed in the experimental and 44 in the control group. In this…

Application of Statistical Quality Control Techniques to Detonator Fabrication: Feasibility Study

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

Jones, J. Frank

1971-05-20

A feasibility study was performed on the use of process control techniques which might reduce the need for a duplicate inspection by production inspection and quality control inspection. Two active detonator fabrication programs were selected for the study. Inspection areas accounting for the greatest percentage of total inspection costs were selected by applying "Pareto's Principle of Maldistribution." Data from these areas were then gathered and analyzed by a process capabiltiy study.

Columbia River : Select Area Fishery Evaluation project : 1995-96 Annual Reports.

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

Hirose, Paul; Miller, Marc; Hill, Jim

1998-06-01

Water quality monitoring was conducted from November 1994 through October 1996 at five Oregon and three Washington select area study sites in the lower Columbia River. Physicochemical monitoring and aquatic biomonitoring programs were established to profile baseline parameters at each study site and document differences between study sites. Data collected at study sites where fish rearing operations were initiated indicate a potential negative impact on the surrounding benthic invertebrate communities.

Sexually selected females in the monogamous Western Australian seahorse.

PubMed

Kvarnemo, Charlotta; Moore, Glenn I; Jones, Adam G

2007-02-22

Studies of sexual selection in monogamous species have hitherto focused on sexual selection among males. Here, we provide empirical documentation that sexual selection can also act strongly on females in a natural population with a monogamous mating system. In our field-based genetic study of the monogamous Western Australian seahorse, Hippocampus subelongatus, sexual selection differentials and gradients show that females are under stronger sexual selection than males: mated females are larger than unmated ones, whereas mated and unmated males do not differ in size. In addition, the opportunity for sexual selection (variance in mating success divided by its mean squared) for females is almost three times that for males. These results, which seem to be generated by a combination of a male preference for larger females and a female-biased adult sex ratio, indicate that substantial sexual selection on females is a potentially important but under-appreciated evolutionary phenomenon in monogamous species.

Sexually selected females in the monogamous Western Australian seahorse

PubMed Central

Kvarnemo, Charlotta; Moore, Glenn I; Jones, Adam G

2006-01-01

Studies of sexual selection in monogamous species have hitherto focused on sexual selection among males. Here, we provide empirical documentation that sexual selection can also act strongly on females in a natural population with a monogamous mating system. In our field-based genetic study of the monogamous Western Australian seahorse, Hippocampus subelongatus, sexual selection differentials and gradients show that females are under stronger sexual selection than males: mated females are larger than unmated ones, whereas mated and unmated males do not differ in size. In addition, the opportunity for sexual selection (variance in mating success divided by its mean squared) for females is almost three times that for males. These results, which seem to be generated by a combination of a male preference for larger females and a female-biased adult sex ratio, indicate that substantial sexual selection on females is a potentially important but under-appreciated evolutionary phenomenon in monogamous species. PMID:17476772

Behavioral Studies in Communication, A Selected Bibliography, 1973.

ERIC Educational Resources Information Center

Steinfatt, Thomas M.

The studies in communication behavior listed in this selected bibliography were published during 1973, unless otherwise specified. Entries are listed under 12 categories: cross cultural communication; diffusion; games, simulations, and conflict; general communication variables; group and organizational communication; interpersonal communication;…

Guidance for Identifying, Selecting and Evaluating Open Literature Studies

EPA Pesticide Factsheets

This guidance for Office of Pesticide Program staff will assist in their evaluation of open literature studies of pesticides. It also describes how we identify, select, and ensure that data we use in risk assessments is of sufficient scientific quality.

Applications of geographic information systems (GIS) for livability : case studies of select transportation agencies

DOT National Transportation Integrated Search

2011-03-31

This report synthesizes the findings from four case studies that assess how select organizations (the City of Boulder, Colorado's Transportation Division, the Center for Neighborhood Technology, the University of Oregon and the Oregon Transportation ...

Study and design of cryogenic propellant acquisition systems. Volume 1: Design studies

NASA Technical Reports Server (NTRS)

Burge, G. W.; Blackmon, J. B.

1973-01-01

An in-depth study and selection of practical propellant surface tension acquisition system designs for two specific future cryogenic space vehicles, an advanced cryogenic space shuttle auxiliary propulsion system and an advanced space propulsion module is reported. A supporting laboratory scale experimental program was also conducted to provide design information critical to concept finalization and selection. Designs using localized pressure isolated surface tension screen devices were selected for each application and preliminary designs were generated. Based on these designs, large scale acquisition prototype hardware was designed and fabricated to be compatible with available NASA-MSFC feed system hardware.

2nd Generation RLV Risk Reduction Definition Program: Pratt & Whitney Propulsion Risk Reduction Requirements Program (TA-3 & TA-4)

NASA Technical Reports Server (NTRS)

Matlock, Steve

2001-01-01

This is the final report and addresses all of the work performed on this program. Specifically, it covers vehicle architecture background, definition of six baseline engine cycles, reliability baseline (space shuttle main engine QRAS), and component level reliability/performance/cost for the six baseline cycles, and selection of 3 cycles for further study. This report further addresses technology improvement selection and component level reliability/performance/cost for the three cycles selected for further study, as well as risk reduction plans, and recommendation for future studies.

Fluorescent Photo-conversion: A second chance to label unique cells

PubMed Central

Mellott, Adam J.; Shinogle, Heather E.; Moore, David S.; Detamore, Michael S.

2014-01-01

Not all cells behave uniformly after treatment in tissue engineering studies. In fact, some treated cells display no signs of treatment or show unique characteristics not consistent with other treated cells. What if the “unique” cells could be isolated from a treated population, and further studied? Photo-convertible reporter proteins, such as Dendra2, allow for the ability to selectively identify unique cells with a secondary label within a primary labeled treated population. In the current study, select cells were identified and labeled through photo-conversion of Dendra2-transfected human Wharton's Jelly cells (hWJCs) for the first time. Robust photo-conversion of green-to-red fluorescence was achieved consistently in arbitrarily selected cells, allowing for precise cell identification of select hWJCs. The current study demonstrates a method that offers investigators the opportunity to selectively label and identify unique cells within a treated population for further study or isolation from the treatment population. Photo-convertible reporter proteins, such as Dendra2, offer the ability over non-photo-convertible reporter proteins, such as green fluorescent protein, to analyze unique individual cells within a treated population, which allows investigators to gain more meaningful information on how a treatment affects all cells within a target population. PMID:25914756

Roost selection by rafinesque's big-eared bats ( Corynorhinus rafinesquii ) in a pristine habitat at three spatial scales

Treesearch

Jessica S. Lucas; Susan C. Loeb; Patrick G. R. Jodice

2015-01-01

Although several studies have described roost use by Rafinesque’s big-eared bats (Corynorhinus rafinesquii), few studies have examined roost selection. We examined roost use and selection by Rafinesque’s big-eared bat at the tree, stand, and landscape scales during the maternity season in pristine old-growth habitat in the Coastal Plain of South...

Do They Get What They Want or Are They Stuck with What They Can Get? Testing Homophily against Default Selection for Friendships of Highly Aggressive Boys. The TRAILS Study

ERIC Educational Resources Information Center

Sijtsema, Jelle J.; Lindenberg, Siegwart M.; Veenstra, Rene

2010-01-01

In this study a homophily selection hypothesis was tested against a default selection hypothesis, to answer whether preferred and realized friendships of highly aggressive boys differed. In a large peer-nomination sample, we assessed who highly overt aggressive, low prosocial boys (n = 181) nominated as friends (preferred friendships) and who…

What Top-Down Task Sets Do for Us: An ERP Study on the Benefits of Advance Preparation in Visual Search

ERIC Educational Resources Information Center

Eimer, Martin; Kiss, Monika; Nicholas, Susan

2011-01-01

When target-defining features are specified in advance, attentional target selection in visual search is controlled by preparatory top-down task sets. We used ERP measures to study voluntary target selection in the absence of such feature-specific task sets, and to compare it to selection that is guided by advance knowledge about target features.…

Investigation into the role of phosphodiesterase IV in bronchorelaxation, including studies with human bronchus.

PubMed Central

Cortijo, J.; Bou, J.; Beleta, J.; Cardelús, I.; Llenas, J.; Morcillo, E.; Gristwood, R. W.

1993-01-01

1. We have investigated the role of cyclic nucleotide phosphodiesterase IV (PDE IV) in the relaxation of human bronchus and guinea-pig trachea in vitro and in guinea-pigs in vivo. 2. Functional studies showed that the selective PDE IV inhibitors, rolipram and denbufylline, relaxed human and guinea-pig preparations in vitro. 3. Two clinically used xanthine non-selective PDE inhibitors, theophylline and pentoxifylline, were also effective in these preparations, but were much less potent than the selective agents used. 4. The rank order of potency for the four PDE inhibitors in both species was similar. 5. Biochemical studies indicated that PDE IV was the major PDE isoform present in the human bronchial tissue. PDEs I, II and V were also identified. 6. Theophylline and pentoxifylline were, as expected, non-selective inhibitors of the human enzymes, but there was a good correlation between PDE IV inhibitory and bronchorelaxation potencies, suggesting that PDE IV inhibition is important for the clinical bronchodilator activities of the two xanthine compounds. 7. We have confirmed the ability of selective PDE IV inhibitors to cause bronchodilatation in guinea-pigs in vivo. 8. We conclude that our study has provided further evidence that selective PDE IV inhibitors could act as bronchodilators in the clinic. PMID:8383567

Successful decoding of famous faces in the fusiform face area.

PubMed

Axelrod, Vadim; Yovel, Galit

2015-01-01

What are the neural mechanisms of face recognition? It is believed that the network of face-selective areas, which spans the occipital, temporal, and frontal cortices, is important in face recognition. A number of previous studies indeed reported that face identity could be discriminated based on patterns of multivoxel activity in the fusiform face area and the anterior temporal lobe. However, given the difficulty in localizing the face-selective area in the anterior temporal lobe, its role in face recognition is still unknown. Furthermore, previous studies limited their analysis to occipito-temporal regions without testing identity decoding in more anterior face-selective regions, such as the amygdala and prefrontal cortex. In the current high-resolution functional Magnetic Resonance Imaging study, we systematically examined the decoding of the identity of famous faces in the temporo-frontal network of face-selective and adjacent non-face-selective regions. A special focus has been put on the face-area in the anterior temporal lobe, which was reliably localized using an optimized scanning protocol. We found that face-identity could be discriminated above chance level only in the fusiform face area. Our results corroborate the role of the fusiform face area in face recognition. Future studies are needed to further explore the role of the more recently discovered anterior face-selective areas in face recognition.

The search and selection for primary studies in systematic reviews published in dental journals indexed in MEDLINE was not fully reproducible.

PubMed

Faggion, Clovis Mariano; Huivin, Raquel; Aranda, Luisiana; Pandis, Nikolaos; Alarcon, Marco

2018-06-01

To evaluate whether the reporting of search strategies and the primary study selection process in dental systematic reviews is reproducible. A survey of systematic reviews published in MEDLINE-indexed dental journals from June 2015 to June 2016 was conducted. Study selection was performed independently by two authors, and the reproducibility of the selection process was assessed using a tool consisting of 12 criteria. Regression analyses were implemented to evaluate any associations between degrees of reporting (measured by the number of items positively answered) and journal impact factor (IF), presence of meta-analysis, and number of citations of the systematic review in Google Scholar. Five hundred and thirty systematic reviews were identified. Following our 12 criteria, none of the systematic reviews had complete reporting of the search strategies and selection process. Eight (1.5%) systematic reviews reported the list of excluded articles (with reasons for exclusion) after title and abstract assessment. Systematic reviews with more positive answers to the criteria were significantly associated with higher journal IF, number of citations, and inclusion of meta-analysis. Search strategies and primary study selection process in systematic reviews published in MEDLINE-indexed dental journals may not be fully reproducible. Copyright © 2018 Elsevier Inc. All rights reserved.

Categorization and identification of simultaneous targets.

PubMed

Theeuwes, J

1991-02-01

Early and late selection theories of visual attention disagree about whether identification occurs before or after selection. Studies showing the category effect, i.e., the time to detect a letter is hardly affected by the number of digits present in the display, are taken as evidence for late selection theories since these studies suggest parallel identification of all items in the display. As an extension of previous studies, in the present study two categorically different targets were presented simultaneously among a variable number of nontargets. Subjects were shown brief displays of two target letters among either 2, 4 or 6 nontarget digits. Subjects responded 'same' when the two letters were identical and 'different' otherwise. Since the 'same-different' response reflects the combined outcome of the simultaneous targets, late-selection theory predicts that the time to match the target letters is independent of the number of nontarget digits. Alternatively, early-selection theory predicts a linear increase of reaction time with display size since the presence of more than one target disrupts parallel preattentive processing, leading to a serial search through all items in the display. The results provide evidence for the early-selection view since reaction time increased linearly with the number of categorically different nontargets. A control experiment revealed that none of the alternative explanations could account for the display size effect.

Impact of random and systematic recall errors and selection bias in case--control studies on mobile phone use and brain tumors in adolescents (CEFALO study).

PubMed

Aydin, Denis; Feychting, Maria; Schüz, Joachim; Andersen, Tina Veje; Poulsen, Aslak Harbo; Prochazka, Michaela; Klaeboe, Lars; Kuehni, Claudia E; Tynes, Tore; Röösli, Martin

2011-07-01

Whether the use of mobile phones is a risk factor for brain tumors in adolescents is currently being studied. Case--control studies investigating this possible relationship are prone to recall error and selection bias. We assessed the potential impact of random and systematic recall error and selection bias on odds ratios (ORs) by performing simulations based on real data from an ongoing case--control study of mobile phones and brain tumor risk in children and adolescents (CEFALO study). Simulations were conducted for two mobile phone exposure categories: regular and heavy use. Our choice of levels of recall error was guided by a validation study that compared objective network operator data with the self-reported amount of mobile phone use in CEFALO. In our validation study, cases overestimated their number of calls by 9% on average and controls by 34%. Cases also overestimated their duration of calls by 52% on average and controls by 163%. The participation rates in CEFALO were 83% for cases and 71% for controls. In a variety of scenarios, the combined impact of recall error and selection bias on the estimated ORs was complex. These simulations are useful for the interpretation of previous case-control studies on brain tumor and mobile phone use in adults as well as for the interpretation of future studies on adolescents. Copyright © 2011 Wiley-Liss, Inc.

Post-Coma Persons with Extensive Multiple Disabilities Use Microswitch Technology to Access Selected Stimulus Events or Operate a Radio Device

ERIC Educational Resources Information Center

Lancioni, Giulio E.; Singh, Nirbhay N.; O'Reilly, Mark F.; Sigafoos, Jeff; Alberti, Gloria; Oliva, Doretta; Megna, Gianfranco; Iliceto, Carla; Damiani, Sabino; Ricci, Irene; Spica, Antonella

2011-01-01

The present two studies extended research evidence on the use of microswitch technology by post-coma persons with multiple disabilities. Specifically, Study I examined whether three adults with a diagnosis of minimally conscious state and multiple disabilities could use microswitches as tools to access brief, selected stimulus events. Study II…

Selection Devices for User of an Electronic Encyclopedia: An Empirical Comparison of Four Possibilities.

ERIC Educational Resources Information Center

Ostroff, Daniel; Shneiderman, Ben

1988-01-01

Describes a study that measured the speed, error rates, and subjective evaluation of arrow jump keys, a jump mouse, number keys, and a touch screen in an interactive encyclopedia. The results of previous studies are discussed as well as the findings of this study. Improvements in selection devices are suggested. (41 references) (Author/CLB)

Phenomenological Study of Business Models Used to Scale Online Enrollment at Institutions of Higher Education

ERIC Educational Resources Information Center

Williams, Dana E.

2012-01-01

The purpose of this qualitative phenomenological study was to explore factors for selecting a business model for scaling online enrollment by institutions of higher education. The goal was to explore the lived experiences of academic industry experts involved in the selection process. The research question for this study was: What were the lived…

Participation without Parity in U.S. Higher Education: Gender, Fields of Study, and Institutional Selectivity

ERIC Educational Resources Information Center

Mullen, Ann L.; Baker, Jayne

2015-01-01

While women now earn more bachelor's degrees than men in many parts of the world, large gender gaps persist in fields of study, and women remain underrepresented in the most prestigious institutions. This study updates and extends the literature on gender disparities in higher education by comparing the selectivity of the institutions where men…

Analysis of single nucleotide polymorphisms in case-control studies.

PubMed

Li, Yonghong; Shiffman, Dov; Oberbauer, Rainer

2011-01-01

Single nucleotide polymorphisms (SNPs) are the most common type of genetic variants in the human genome. SNPs are known to modify susceptibility to complex diseases. We describe and discuss methods used to identify SNPs associated with disease in case-control studies. An outline on study population selection, sample collection and genotyping platforms is presented, complemented by SNP selection, data preprocessing and analysis.

A Study of Teacher Opinions Concerning Selected Free Filmstrips Provided by the American Iron and Steel Institute to Schools Throughout the United States.

ERIC Educational Resources Information Center

DuVall, Charles R.; And Others

This study analyzed teacher assessment of several factors related to selected filmstrips provided to teachers by the American Iron and Steel Institute. Main concerns of the study related to applicability of the filmstrip to instructional programs, assessment of accuracy of information contained, effectiveness of content, effectiveness of…

National Study of Word Processing Installations in Selected Business Organizations. A Report on the National Word Processing Research Study of Delta Pi Epsilon.

ERIC Educational Resources Information Center

Scriven, Jolene D.; And Others

A study was conducted (1) to determine current practices in word processing installations in selected organizations throughout the United States, and (2) to ascertain anticipated future developments in word processing as well as to provide recommendations for educational institutions that prepare workers for business offices. Seven interview…

A Phenomenological Case Study of the Elementary to Secondary Transition for One Female Student Diagnosed with Selective Mutism

ERIC Educational Resources Information Center

Nashman-Smith, Mona

2017-01-01

Selective mutism (SM) is considered a communication and anxiety disorder that afflicts about 1% of students. The rarity of SM and the isolated cases of this condition has rendered the elementary to secondary school experience for a student with SM difficult to study. Utilizing a qualitative approach, this phenomenological case study examined the…

Using the Self-Directed Search in Research: Selecting a Representative Pool of Items to Measure Vocational Interests

ERIC Educational Resources Information Center

Poitras, Sarah-Caroline; Guay, Frederic; Ratelle, Catherine F.

2012-01-01

Using Item Response Theory (IRT) and Confirmatory Factor Analysis (CFA), the goal of this study was to select a reduced pool of items from the French Canadian version of the Self-Directed Search--Activities Section (Holland, Fritzsche, & Powell, 1994). Two studies were conducted. Results of Study 1, involving 727 French Canadian students,…

"Tell Me a Story": The Use of Narrative as a Learning Tool for Natural Selection

ERIC Educational Resources Information Center

Prins, Renate; Avraamidou, Lucy; Goedhart, Martin

2017-01-01

Grounded within literature pointing to the value of narrative in communicating scientific information, the purpose of this study was to examine the use of stories as a tool for teaching about natural selection in the context of school science. The study utilizes a mixed method, case study approach which focuses on the design, implementation, and…

The G matrix under fluctuating correlational mutation and selection.

PubMed

Revell, Liam J

2007-08-01

Theoretical quantitative genetics provides a framework for reconstructing past selection and predicting future patterns of phenotypic differentiation. However, the usefulness of the equations of quantitative genetics for evolutionary inference relies on the evolutionary stability of the additive genetic variance-covariance matrix (G matrix). A fruitful new approach for exploring the evolutionary dynamics of G involves the use of individual-based computer simulations. Previous studies have focused on the evolution of the eigenstructure of G. An alternative approach employed in this paper uses the multivariate response-to-selection equation to evaluate the stability of G. In this approach, I measure similarity by the correlation between response-to-selection vectors due to random selection gradients. I analyze the dynamics of G under several conditions of correlational mutation and selection. As found in a previous study, the eigenstructure of G is stabilized by correlational mutation and selection. However, over broad conditions, instability of G did not result in a decreased consistency of the response to selection. I also analyze the stability of G when the correlation coefficients of correlational mutation and selection and the effective population size change through time. To my knowledge, no prior study has used computer simulations to investigate the stability of G when correlational mutation and selection fluctuate. Under these conditions, the eigenstructure of G is unstable under some simulation conditions. Different results are obtained if G matrix stability is assessed by eigenanalysis or by the response to random selection gradients. In this case, the response to selection is most consistent when certain aspects of the eigenstructure of G are least stable and vice versa.

Silymarin-Loaded Eudragit Nanoparticles: Formulation, Characterization, and Hepatoprotective and Toxicity Evaluation.

PubMed

El-Nahas, Amira E; Allam, Ahmed N; Abdelmonsif, Doaa A; El-Kamel, Amal H

2017-11-01

The objectives of this study were to formulate, characterize silymarin-loaded Eudragit nanoparticles (SNPs) and evaluate their hepatoprotective and cytotoxic effects after oral administration. SNPs were prepared by nanoprecipitation technique and were evaluated for particle size, entrapment efficiency, TEM, solid-state characterization, and in vitro drug release. The hepatoprotective activity was evaluated after oral administration of selected SNPs in carbon tetrachloride-intoxicated rats. Potential in vivo acute cytotoxicity study was also assessed. The selected SNPs contained 50 mg silymarin and 50 mg Eudragit polymers (1:1 w/w Eudragit RS 100 & Eudragit LS 100). Morphology of the selected SNPs (particle size of 84.70 nm and entrapment efficiency of 83.45% with 100% drug release after 12 h) revealed spherical and uniformly distributed nanoparticles. DSC and FT-IR studies suggested the presence of silymarin in an amorphous state and absence of chemical interaction. The hepatoprotective evaluation of the selected SNPs in CCl 4 -intoxicated rats revealed significant improvement in the activities of different biochemical parameters (P ≤ 0.01) compared to the marketed product. The histopathological studies suggested that the selected SNPs produced better hepatoprotective effect in CCl 4 -intoxicated rats compared with the commercially marketed product. Toxicity study revealed no evident toxic effect for blank or silymarin-loaded nanoparticles at the dose level of 50 mg/kg body weight. The obtained results suggested that the selected SNPs were safe and potentially offered enhancement in the pharmacological hepatoprotective properties of silymarin.

Studies on the factors modulating indole-3-acetic acid production in endophytic bacterial isolates from Piper nigrum and molecular analysis of ipdc gene.

PubMed

Jasim, B; Jimtha John, C; Shimil, V; Jyothis, M; Radhakrishnan, E K

2014-09-01

The study mainly aimed quantitative analysis of IAA produced by endophytic bacteria under various conditions including the presence of extract from Piper nigrum. Analysis of genetic basis of IAA production was also conducted by studying the presence and diversity of the ipdc gene among the selected isolates. Five endophytic bacteria isolated previously from P. nigrum were used for the study. The effect of temperature, pH, agitation, tryptophan concentration and plant extract on modulating IAA production of selected isolates was analysed by colorimetric method. Comparative and quantitative analysis of IAA production by colorimetric isolates under optimal culture condition was analysed by HPTLC method. Presence of ipdc gene and thereby biosynthetic basis of IAA production among the selected isolates were studied by PCR-based amplification and subsequent insilico analysis of sequence obtained. Among the selected bacterial isolates from P. nigrum, isolate PnB 8 (Klebsiella pneumoniae) was found to have the maximum yield of IAA under various conditions optimized and was confirmed by colorimetric, HPLC and HPTLC analysis. Very interestingly, the study showed stimulating effect of phytochemicals from P. nigrum on IAA production by endophytic bacteria isolated from same plant. This study is unique because of the selection of endophytes from same source for comparative and quantitative analysis of IAA production under various conditions. Study on stimulatory effect of phytochemicals on bacterial IAA production as explained in the study is a novel approach. Studies on molecular basis of IAA production which was confirmed by sequence analysis of ipdc gene make the study scientifically attractive. Even though microbial production of IAA is well known, current report on detailed optimization, effect of plant extract and molecular confirmation of IAA biosynthesis is comparatively novel in its approach. © 2014 The Society for Applied Microbiology.

How effective are selection methods in medical education? A systematic review.

PubMed

Patterson, Fiona; Knight, Alec; Dowell, Jon; Nicholson, Sandra; Cousans, Fran; Cleland, Jennifer

2016-01-01

Selection methods used by medical schools should reliably identify whether candidates are likely to be successful in medical training and ultimately become competent clinicians. However, there is little consensus regarding methods that reliably evaluate non-academic attributes, and longitudinal studies examining predictors of success after qualification are insufficient. This systematic review synthesises the extant research evidence on the relative strengths of various selection methods. We offer a research agenda and identify key considerations to inform policy and practice in the next 50 years. A formalised literature search was conducted for studies published between 1997 and 2015. A total of 194 articles met the inclusion criteria and were appraised in relation to: (i) selection method used; (ii) research question(s) addressed, and (iii) type of study design. Eight selection methods were identified: (i) aptitude tests; (ii) academic records; (iii) personal statements; (iv) references; (v) situational judgement tests (SJTs); (vi) personality and emotional intelligence assessments; (vii) interviews and multiple mini-interviews (MMIs), and (viii) selection centres (SCs). The evidence relating to each method was reviewed against four evaluation criteria: effectiveness (reliability and validity); procedural issues; acceptability, and cost-effectiveness. Evidence shows clearly that academic records, MMIs, aptitude tests, SJTs and SCs are more effective selection methods and are generally fairer than traditional interviews, references and personal statements. However, achievement in different selection methods may differentially predict performance at the various stages of medical education and clinical practice. Research into selection has been over-reliant on cross-sectional study designs and has tended to focus on reliability estimates rather than validity as an indicator of quality. A comprehensive framework of outcome criteria should be developed to allow researchers to interpret empirical evidence and compare selection methods fairly. This review highlights gaps in evidence for the combination of selection tools that is most effective and the weighting to be given to each tool. © 2015 John Wiley & Sons Ltd.

Sexual selection expedites the evolution of pesticide resistance.

PubMed

Jacomb, Frances; Marsh, Jason; Holman, Luke

2016-12-01

The evolution of insecticide resistance by crop pests and disease vectors causes serious problems for agriculture and health. Sexual selection can accelerate or hinder adaptation to abiotic challenges in a variety of ways, but the effect of sexual selection on resistance evolution is little studied. Here, we examine this question using experimental evolution in the pest insect Tribolium castaneum. The experimental removal of sexual selection slowed the evolution of resistance in populations treated with pyrethroid pesticide, and also reduced the rate at which resistance was lost from pesticide-free populations. These results suggest that selection arising from variance in mating and fertilization success can augment natural selection on pesticide resistance, meaning that sexual selection should be considered when designing strategies to limit the evolution of pesticide resistance. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

Genomic Signature of Kin Selection in an Ant with Obligately Sterile Workers

PubMed Central

Warner, Michael R.; Mikheyev, Alexander S.

2017-01-01

Abstract Kin selection is thought to drive the evolution of cooperation and conflict, but the specific genes and genome-wide patterns shaped by kin selection are unknown. We identified thousands of genes associated with the sterile ant worker caste, the archetype of an altruistic phenotype shaped by kin selection, and then used population and comparative genomic approaches to study patterns of molecular evolution at these genes. Consistent with population genetic theoretical predictions, worker-upregulated genes experienced reduced selection compared with genes upregulated in reproductive castes. Worker-upregulated genes included more taxonomically restricted genes, indicating that the worker caste has recruited more novel genes, yet these genes also experienced reduced selection. Our study identifies a putative genomic signature of kin selection and helps to integrate emerging sociogenomic data with longstanding social evolution theory. PMID:28419349

Optimal selection of markers for validation or replication from genome-wide association studies.

PubMed

Greenwood, Celia M T; Rangrej, Jagadish; Sun, Lei

2007-07-01

With reductions in genotyping costs and the fast pace of improvements in genotyping technology, it is not uncommon for the individuals in a single study to undergo genotyping using several different platforms, where each platform may contain different numbers of markers selected via different criteria. For example, a set of cases and controls may be genotyped at markers in a small set of carefully selected candidate genes, and shortly thereafter, the same cases and controls may be used for a genome-wide single nucleotide polymorphism (SNP) association study. After such initial investigations, often, a subset of "interesting" markers is selected for validation or replication. Specifically, by validation, we refer to the investigation of associations between the selected subset of markers and the disease in independent data. However, it is not obvious how to choose the best set of markers for this validation. There may be a prior expectation that some sets of genotyping data are more likely to contain real associations. For example, it may be more likely for markers in plausible candidate genes to show disease associations than markers in a genome-wide scan. Hence, it would be desirable to select proportionally more markers from the candidate gene set. When a fixed number of markers are selected for validation, we propose an approach for identifying an optimal marker-selection configuration by basing the approach on minimizing the stratified false discovery rate. We illustrate this approach using a case-control study of colorectal cancer from Ontario, Canada, and we show that this approach leads to substantial reductions in the estimated false discovery rates in the Ontario dataset for the selected markers, as well as reductions in the expected false discovery rates for the proposed validation dataset. Copyright 2007 Wiley-Liss, Inc.

Developing the Alphabetic Principle to Aid Text-Based Augmentative and Alternative Communication Use by Adults With Low Speech Intelligibility and Intellectual Disabilities.

PubMed

Schmidt-Naylor, Anna C; Saunders, Kathryn J; Brady, Nancy C

2017-05-17

We explored alphabet supplementation as an augmentative and alternative communication strategy for adults with minimal literacy. Study 1's goal was to teach onset-letter selection with spoken words and assess generalization to untaught words, demonstrating the alphabetic principle. Study 2 incorporated alphabet supplementation within a naming task and then assessed effects on speech intelligibility. Three men with intellectual disabilities (ID) and low speech intelligibility participated. Study 1 used a multiple-probe design, across three 20-word sets, to show that our computer-based training improved onset-letter selection. We also probed generalization to untrained words. Study 2 taught onset-letter selection for 30 new words chosen for functionality. Five listeners transcribed speech samples of the 30 words in 2 conditions: speech only and speech with alphabet supplementation. Across studies 1 and 2, participants demonstrated onset-letter selection for at least 90 words. Study 1 showed evidence of the alphabetic principle for some but not all word sets. In study 2, participants readily used alphabet supplementation, enabling listeners to understand twice as many words. This is the first demonstration of alphabet supplementation in individuals with ID and minimal literacy. The large number of words learned holds promise both for improving communication and providing a foundation for improved literacy.

Water and Agricultural-Chemical Transport in a Midwestern, Tile-Drained Watershed: Implications for Conservation Practices

USGS Publications Warehouse

Baker, Nancy T.; Stone, Wesley W.; Frey, Jeffrey W.; Wilson, John T.

2007-01-01

The study of agricultural chemicals is one of five national priority topics being addressed by the National Water-Quality Assessment (NAWQA) Program in its second decade of studies, which began in 2001. Seven watersheds across the Nation were selected for the NAWQA agricultural-chemical topical study. The watersheds selected represent a range of agricultural settings - with varying crop types and agricultural practices related to tillage, irrigation, artificial drainage, and chemical use - as well as a range of landscapes with different geology, soils, topography, climate, and hydrology (Capel and others, 2004). Chemicals selected for study include nutrients (nitrogen and phosphorus) and about 50 commonly used pesticides. This study design leads to an improved understanding of many factors that can affect the movement of water and chemicals in different agricultural settings. Information from these studies will help with decision making related to chemical use, conservation, and other farming practices that are used to reduce runoff of agricultural chemicals and sediment from fields (Capel and others, 2004). This Fact Sheet highlights the results of the NAWQA agricultural chemical study in the Leary Weber Ditch Watershed in Hancock County, Indiana. This watershed was selected to represent a tile-drained, corn and soybean, humid area typical in the Midwest.

Bioinformatic analyses to select phenotype affecting polymorphisms in HTR2C gene.

PubMed

Piva, Francesco; Giulietti, Matteo; Baldelli, Luisa; Nardi, Bernardo; Bellantuono, Cesario; Armeni, Tatiana; Saccucci, Franca; Principato, Giovanni

2011-08-01

Single nucleotide polymorphisms (SNPs) in serotonin related genes influence mental disorders, responses to pharmacological and psychotherapeutic treatments. In planning association studies, researchers that want to investigate new SNPs have to select some among a large number of candidates. Our aim is to guide researchers in the selection of the most likely phenotype affecting polymorphisms. Here, we studied serotonin receptor 2C (HTR2C) SNPs because, till now, only relatively few of about 2000 are investigated. We used the most updated and assessed bioinformatic tools to predict which variations can give rise to biological effects among 2450 HTR2C SNPs. We suggest 48 SNPs that are worth considering in future association studies in the field of psychiatry, psychology and pharmacogenomics. Moreover, our analyses point out the biological level probably affected, such as transcription, splicing, miRNA regulation and protein structure, thus allowing to suggest future molecular investigations. Although few association studies are available in literature, their results are in agreement with our predictions, showing that our selection methods can help to guide future association studies. Copyright © 2011 John Wiley & Sons, Ltd.

Sexual selection and genetic colour polymorphisms in animals.

PubMed

Wellenreuther, Maren; Svensson, Erik I; Hansson, Bengt

2014-11-01

Genetic colour polymorphisms are widespread across animals and often subjected to complex selection regimes. Traditionally, colour morphs were used as simple visual markers to measure allele frequency changes in nature, selection, population divergence and speciation. With advances in sequencing technology and analysis methods, several model systems are emerging where the molecular targets of selection are being described. Here, we discuss recent studies on the genetics of sexually selected colour polymorphisms, aiming at (i) reviewing the evidence of sexual selection on colour polymorphisms, (ii) highlighting the genetic architecture, molecular and developmental basis underlying phenotypic colour diversification and (iii) discuss how the maintenance of such polymorphisms might be facilitated or constrained by these. Studies of the genetic architecture of colour polymorphism point towards the importance of tight clustering of colour loci with other trait loci, such as in the case of inversions and supergene structures. Other interesting findings include linkage between colour loci and mate preferences or sex determination, and the role of introgression and regulatory variation in fuelling polymorphisms. We highlight that more studies are needed that explicitly integrate fitness consequences of sexual selection on colour with the underlying molecular targets of colour to gain insights into the evolutionary consequences of sexual selection on polymorphism maintenance. © 2014 John Wiley & Sons Ltd.

Testing for a genetic response to sexual selection in a wild Drosophila population.

PubMed

Gosden, T P; Thomson, J R; Blows, M W; Schaul, A; Chenoweth, S F

2016-06-01

In accordance with the consensus that sexual selection is responsible for the rapid evolution of display traits on macroevolutionary scales, microevolutionary studies suggest sexual selection is a widespread and often strong form of directional selection in nature. However, empirical evidence for the contemporary evolution of sexually selected traits via sexual rather than natural selection remains weak. In this study, we used a novel application of quantitative genetic breeding designs to test for a genetic response to sexual selection on eight chemical display traits from a field population of the fly, Drosophila serrata. Using our quantitative genetic approach, we were able to detect a genetically based difference in means between groups of males descended from fathers who had either successfully sired offspring or were randomly collected from the same wild population for one of these display traits, the diene (Z,Z)-5,9-C27 : 2 . Our experimental results, in combination with previous laboratory studies on this system, suggest that both natural and sexual selection may be influencing the evolutionary trajectories of these traits in nature, limiting the capacity for a contemporary evolutionary response. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

Selection, constraint, and the evolution of coloration in African starlings.

PubMed

Maia, Rafael; Rubenstein, Dustin R; Shawkey, Matthew D

2016-05-01

Colorful plumage plays a prominent role in the evolution of birds, influencing communication (sexual/social selection), and crypsis (natural selection). Comparative studies have focused primarily on these selective pressures, but the mechanisms underlying color production can also be important by constraining the color gamut upon which selection acts. Iridescence is particularly interesting to study the interaction between selection and color-producing mechanisms because a broad range of colors can be produced with a shared template, and innovations to this template further expand this by increasing the parameters interacting to produce colors. We examine the patterns of ornamentation and dichromatism evolution in African starlings, a group remarkably diverse in color production mechanisms, social systems, and ecologies. We find that the presence of iridescence is ancestral to the group, being predominantly lost in females and cooperative breeders, as well as species with less labile templates. Color-producing mechanisms interact and are the main predictors of plumage ornamentation and elaboration, with little influence of selective pressures in their evolution. Dichromatism, however is influenced by social system and the loss of iridescence. Our results show the importance of considering both selection and constraints, and the different roles that they may have, in the evolution of ornamentation and dimorphism. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

Candidate loci involved in domestication and improvement detected by a published 90K wheat SNP array

PubMed Central

Gao, Lifeng; Zhao, Guangyao; Huang, Dawei; Jia, Jizeng

2017-01-01

Selection is one of the most important forces in crop evolution. Common wheat is a major world food crop and a typical allopolyploid with a huge and complex genome. We applied four approaches to detect loci selected in wheat during domestication and improvement. A total of 7,984 candidate loci were detected, accounting for 23.3% of all 34,317 SNPs analysed, a much higher proportion than estimated in previous reports. We constructed a first generation wheat selection map which revealed the following new insights on genome-wide selection: (1) diversifying selection acted by increasing, decreasing or not affecting gene frequencies; (2) the number of loci under selection during domestication was much higher than that during improvement; (3) the contribution to wheat improvement by the D sub-genome was relatively small due to the bottleneck of hexaploidisation and diversity can be expanded by using synthetic wheat and introgression lines; and (4) clustered selection regions occur throughout the wheat genome, including the centromere regions. This study will not only help future wheat breeding and evolutionary studies, but will also accelerate study of other crops, especially polyploids. PMID:28327671

Signatures of selection in tilapia revealed by whole genome resequencing.

PubMed

Xia, Jun Hong; Bai, Zhiyi; Meng, Zining; Zhang, Yong; Wang, Le; Liu, Feng; Jing, Wu; Wan, Zi Yi; Li, Jiale; Lin, Haoran; Yue, Gen Hua

2015-09-16

Natural selection and selective breeding for genetic improvement have left detectable signatures within the genome of a species. Identification of selection signatures is important in evolutionary biology and for detecting genes that facilitate to accelerate genetic improvement. However, selection signatures, including artificial selection and natural selection, have only been identified at the whole genome level in several genetically improved fish species. Tilapia is one of the most important genetically improved fish species in the world. Using next-generation sequencing, we sequenced the genomes of 47 tilapia individuals. We identified a total of 1.43 million high-quality SNPs and found that the LD block sizes ranged from 10-100 kb in tilapia. We detected over a hundred putative selective sweep regions in each line of tilapia. Most selection signatures were located in non-coding regions of the tilapia genome. The Wnt signaling, gonadotropin-releasing hormone receptor and integrin signaling pathways were under positive selection in all improved tilapia lines. Our study provides a genome-wide map of genetic variation and selection footprints in tilapia, which could be important for genetic studies and accelerating genetic improvement of tilapia.

Why Do Floral Perfumes Become Different? Region-Specific Selection on Floral Scent in a Terrestrial Orchid

PubMed Central

Gross, Karin; Sun, Mimi; Schiestl, Florian P.

2016-01-01

Geographically structured phenotypic selection can lead to adaptive divergence. However, in flowering plants, such divergent selection has rarely been shown, and selection on floral signals is generally little understood. In this study, we measured phenotypic selection on display size, floral color, and floral scent in four lowland and four mountain populations of the nectar-rewarding terrestrial orchid Gymnadenia odoratissima in two years. We also quantified population differences in these traits and pollinator community composition. Our results show positive selection on display size and positive, negative, or absence of selection on different scent compounds and floral color. Selection on the main scent compounds was consistently stronger in the lowlands than in the mountains, and lowland plants emitted higher amounts of most of these compounds. Pollinator community composition also differed between regions, suggesting different pollinators select for differences in floral volatiles. Overall, our study is the first to document consistent regional differences in selection on floral scent, suggesting this pattern of selection is one of the evolutionary forces contributing to regional divergence in floral chemical signaling. PMID:26886766

Inevitable Relative Age Effects in Different Stages of the Selection Process among Male and Female Youth Soccer Players.

PubMed

Lagestad, Pål; Steen, Ingebrigt; Dalen, Terje

2018-03-31

The relative age effect (RAE) in the selection of young soccer players is a well-known phenomenon. The purpose of this study was to examine the relative age effect existing despite strategies that have been implemented to avoid its presence in the selection process. We also aimed to investigate the RAE during the three different selection stages for B13, B14 (boys), and G13, G14 (girls), and gender differences in the RAE. This was achieved by collecting data from everyone who played soccer in Troendelag, and data that would illuminate the RAE during the three stages of selection for the regional teams of the 2015/2016 season. Mann⁻Whitney U-tests and Chi-square tests were used as statistical methods. The main finding of this study is that, despite the intention to reduce RAE in the selection process according to the criterion that at least 40% of the players should be born in the second half of the year, both the early-born boys and girls are more likely to be selected. The results also show that the RAE occurs gradually, and the longer the players are in the selection process the more prominent it is. This study highlights the importance of being aware of the RAE when selecting young players.

Space station needs, attributes and architectural options study. Volume 1: Executive study

NASA Technical Reports Server (NTRS)

1983-01-01

Mission identification and validation, the benefits of a manned presence in space; attributes and architectures; time-phased mission and system requirements imposed on the space station; orbit selection; space station architectural options; technology selection; and program planning are addressed.

Effects of raising and lowering speed limits on selected roadway sections

DOT National Transportation Integrated Search

1997-01-01

The objective of this research was to examine the effects of raising and lowering posted speed limits on driver behavior for urban and rural nonlimited access highways. Sites selected for study were furnished by the participating States. The study wa...

PARTICLE SIZE DISTRIBUTIONS FROM SELECT RESIDENCES PARTICIPATING IN THE NERL RTP PM PANEL STUDY

EPA Science Inventory

Particle Size Distributions from Select Residences Participating in the NERL RTP PM Panel Study. Alan Vette, Ronald Williams, and Michael Riediker, U.S. Environmental Protection Agency, National Exposure Research Laboratory, Research Triangle Park, NC 27711; Jonathan Thornburg...

Tunnel-Site Selection by Remote Sensing Techniques

DTIC Science & Technology

A study of the role of remote sensing for geologic reconnaissance for tunnel-site selection was commenced. For this study, remote sensing was defined...conventional remote sensing . Future research directions are suggested, and the extension of remote sensing to include airborne passive microwave

Dominant selectable markers for Penicillium spp. transformation and gene function studies

USDA-ARS?s Scientific Manuscript database

Penicillium spp. has been genetically manipulated and gene function studies have utilized single gene deletion strains for phenotypic analysis. Fungal transformation experiments have relied on hygromycin and hygromycin phosphotransferase (hph) as the main dominant selectable marker (DSM) system in P...

Overexpression of COX-2 in Rat Oral Cancers and Prevention of Oral Carcinogenesis in Rats by Selective and Non-Selective COX Inhibitors

PubMed Central

McCormick, David L.; Phillips, Jonathan M.; Horn, Thomas L.; Johnson, William D.; Steele, Vernon E.; Lubet, Ronald A.

2009-01-01

Oral squamous cell carcinomas induced in rats by 4-nitroquinoline-1-oxide (NQO) demonstrate substantial overexpression of cyclooxygenase-2 (COX-2) when compared to adjacent phenotypically normal oral tissues. By contrast, neither 5-lipoxygenase (5-LOX) nor 12-lipoxygenase (12-LOX) is overexpressed in rat oral cancers. Two chemoprevention studies were performed to test the resulting hypothesis that COX-2 is a useful target for oral cancer chemoprevention in the rat. In both studies, male F344 rats received drinking water exposure to NQO (20 ppm) for 10 weeks, followed by administration of chemopreventive agents from week 10 until study termination at week 26. In the first study, groups of rats were fed basal diet (control), or basal diet supplemented with the selective COX-2 inhibitor, celecoxib (500 or 1500 mg/kg diet); the non-selective COX inhibitor, piroxicam (50 or 150 mg/kg diet); or the 5-LOX inhibitor, zileuton (2000 mg/kg diet). In the second study, rats were fed basal diet (control) or basal diet supplemented with NO-Naproxen (180 or 90 mg/kg diet), a non-selective COX inhibitor that demonstrates reduced gastrointestinal toxicity. When compared to dietary controls, celecoxib decreased oral cancer incidence, cancer invasion score, and cancer-related mortality. Piroxicam decreased cancer-related mortality and cancer invasion score, while NO-naproxen decreased oral cancer incidence and cancer invasion score. By contrast, zileuton demonstrated no chemopreventive activity by any parameter assessed. These data demonstrate that both selective and non-selective inhibitors of COX-2 can prevent NQO-induced oral carcinogenesis in rats. The chemopreventive activity of COX inhibitors may be linked to overexpression of their enzymatic target in incipient oral neoplasms. PMID:20051374

Selection bias in population-based cancer case-control studies due to incomplete sampling frame coverage.

PubMed

Walsh, Matthew C; Trentham-Dietz, Amy; Gangnon, Ronald E; Nieto, F Javier; Newcomb, Polly A; Palta, Mari

2012-06-01

Increasing numbers of individuals are choosing to opt out of population-based sampling frames due to privacy concerns. This is especially a problem in the selection of controls for case-control studies, as the cases often arise from relatively complete population-based registries, whereas control selection requires a sampling frame. If opt out is also related to risk factors, bias can arise. We linked breast cancer cases who reported having a valid driver's license from the 2004-2008 Wisconsin women's health study (N = 2,988) with a master list of licensed drivers from the Wisconsin Department of Transportation (WDOT). This master list excludes Wisconsin drivers that requested their information not be sold by the state. Multivariate-adjusted selection probability ratios (SPR) were calculated to estimate potential bias when using this driver's license sampling frame to select controls. A total of 962 cases (32%) had opted out of the WDOT sampling frame. Cases age <40 (SPR = 0.90), income either unreported (SPR = 0.89) or greater than $50,000 (SPR = 0.94), lower parity (SPR = 0.96 per one-child decrease), and hormone use (SPR = 0.93) were significantly less likely to be covered by the WDOT sampling frame (α = 0.05 level). Our results indicate the potential for selection bias due to differential opt out between various demographic and behavioral subgroups of controls. As selection bias may differ by exposure and study base, the assessment of potential bias needs to be ongoing. SPRs can be used to predict the direction of bias when cases and controls stem from different sampling frames in population-based case-control studies.

The spatial patterns of directional phenotypic selection.

PubMed

Siepielski, Adam M; Gotanda, Kiyoko M; Morrissey, Michael B; Diamond, Sarah E; DiBattista, Joseph D; Carlson, Stephanie M

2013-11-01

Local adaptation, adaptive population divergence and speciation are often expected to result from populations evolving in response to spatial variation in selection. Yet, we lack a comprehensive understanding of the major features that characterise the spatial patterns of selection, namely the extent of variation among populations in the strength and direction of selection. Here, we analyse a data set of spatially replicated studies of directional phenotypic selection from natural populations. The data set includes 60 studies, consisting of 3937 estimates of selection across an average of five populations. We performed meta-analyses to explore features characterising spatial variation in directional selection. We found that selection tends to vary mainly in strength and less in direction among populations. Although differences in the direction of selection occur among populations they do so where selection is often weakest, which may limit the potential for ongoing adaptive population divergence. Overall, we also found that spatial variation in selection appears comparable to temporal (annual) variation in selection within populations; however, several deficiencies in available data currently complicate this comparison. We discuss future research needs to further advance our understanding of spatial variation in selection. © 2013 John Wiley & Sons Ltd/CNRS.

Active control of methanol carbonylation selectivity over Au/carbon anode by electrochemical potential.

PubMed

Funakawa, Akiyasu; Yamanaka, Ichiro; Otsuka, Kiyoshi

2005-05-12

Electrochemical oxidative carbonylation of methanol was studied over Au supported carbon anode in CO. The major carbonylation products were dimethyl oxalate (DMO) and dimethyl carbonate (DMC). The minor oxidation products were dimethoxy methane (DMM) and methyl formate (MF) from methanol and CO(2). Influences of various reaction conditions were studied on carbonylation activities and selectivities. The selectivities to DMO and DMC can be controlled by the electrochemical potential. Electrocatalysis of Au/carbon anode was studied by cyclic voltammetry (CV), stoichiometric reactions among Au(3+), methanol, and CO, and UV-vis spectra. The Au/carbon anode was characterized by XRD, SEM, and BE images before and after the carbonylation. These experimental facts strongly suggest that transition of oxidation states of Au affects changing of the carbonylation selectivities to DMO and DMC. Au(0) is the active species for the selective DMO formation by direct electrochemical carbonylation at low potentials (<+1.2 V (Ag/AgCl)). On the other hand, Au(3+) is the active spices for the selective DMC formation by indirect electrochemical carbonylation through Au(3+)/Au(+) redox at high potentials (>+1.3 V).

Reactor technology assessment and selection utilizing systems engineering approach

NASA Astrophysics Data System (ADS)

Zolkaffly, Muhammed Zulfakar; Han, Ki-In

2014-02-01

The first Nuclear power plant (NPP) deployment in a country is a complex process that needs to consider technical, economic and financial aspects along with other aspects like public acceptance. Increased interest in the deployment of new NPPs, both among newcomer countries and those with expanding programs, necessitates the selection of reactor technology among commercially available technologies. This paper reviews the Systems Decision Process (SDP) of Systems Engineering and applies it in selecting the most appropriate reactor technology for the deployment in Malaysia. The integrated qualitative and quantitative analyses employed in the SDP are explored to perform reactor technology assessment and to select the most feasible technology whose design has also to comply with the IAEA standard requirements and other relevant requirements that have been established in this study. A quick Malaysian case study result suggests that the country reside with PWR (pressurized water reactor) technologies with more detailed study to be performed in the future for the selection of the most appropriate reactor technology for Malaysia. The demonstrated technology assessment also proposes an alternative method to systematically and quantitatively select the most appropriate reactor technology.

Genetic evidence for extreme polyandry and extraordinary sex-role reversal in a pipefish.

PubMed

Jones, A G; Walker, D; Avise, J C

2001-12-22

Due to the phenomenon of male pregnancy, the fish family Syngnathidae (seahorses and pipefishes) has historically been considered an archetypal example of a group in which sexual selection should act more strongly on females than on males. However, more recent work has called into question the idea that all species with male pregnancy are sex-role reversed with respect to the intensity of sexual selection. Furthermore, no studies have formally quantified the opportunity for sexual selection in any natural breeding assemblage of pipefishes or seahorses in order to demonstrate conclusively that sexual selection acts most strongly on females. Here, we use a DNA-based study of parentage in the Gulf pipefish Syngnathus scovelli in order to show that sexual selection indeed acts more strongly on females than on males in this species. Moreover, the Gulf pipefish exhibits classical polyandry with the greatest asymmetry in reproductive roles (as quantified by variances in mating success) between males and females yet documented in any system. Thus, the intensity of sexual selection on females in pipefish rivals that of any other taxon yet studied.

Genetic evidence for extreme polyandry and extraordinary sex-role reversal in a pipefish.

PubMed Central

Jones, A. G.; Walker, D.; Avise, J. C.

2001-01-01

Due to the phenomenon of male pregnancy, the fish family Syngnathidae (seahorses and pipefishes) has historically been considered an archetypal example of a group in which sexual selection should act more strongly on females than on males. However, more recent work has called into question the idea that all species with male pregnancy are sex-role reversed with respect to the intensity of sexual selection. Furthermore, no studies have formally quantified the opportunity for sexual selection in any natural breeding assemblage of pipefishes or seahorses in order to demonstrate conclusively that sexual selection acts most strongly on females. Here, we use a DNA-based study of parentage in the Gulf pipefish Syngnathus scovelli in order to show that sexual selection indeed acts more strongly on females than on males in this species. Moreover, the Gulf pipefish exhibits classical polyandry with the greatest asymmetry in reproductive roles (as quantified by variances in mating success) between males and females yet documented in any system. Thus, the intensity of sexual selection on females in pipefish rivals that of any other taxon yet studied. PMID:11749706

The Development of Memory Efficiency and Value-Directed Remembering Across the Lifespan: A Cross-Sectional Study of Memory and Selectivity

PubMed Central

Castel, Alan D.; Humphreys, Kathryn L.; Lee, Steve S.; Galván, Adriana; Balota, David A.; McCabe, David P.

2012-01-01

Although attentional control and memory change considerably across the lifespan, no research has examined how the ability to strategically remember important information (i.e., value-directed remembering) changes from childhood to old age. The present study examined this in different age groups across the lifespan (N=320, 5 to 96 years old). We employed a selectivity task where participants were asked to study and recall items worth different point values in order to maximize their point score. This procedure allowed for measures of memory quantity/capacity (number of words recalled) and memory efficiency/selectivity (the recall of high-value items relative to low-value items). Age-related differences were found for memory capacity, as young adults recalled more words than the other groups. However, in terms of selectivity, younger and older adults were more selective than adolescents and children. The dissociation between these measures across the lifespan illustrates important age-related differences in terms of memory capacity and the ability to selectively remember high-value information. PMID:21942664

Selecting the most appropriate inferential statistical test for your quantitative research study.

PubMed

Bettany-Saltikov, Josette; Whittaker, Victoria Jane

2014-06-01

To discuss the issues and processes relating to the selection of the most appropriate statistical test. A review of the basic research concepts together with a number of clinical scenarios is used to illustrate this. Quantitative nursing research generally features the use of empirical data which necessitates the selection of both descriptive and statistical tests. Different types of research questions can be answered by different types of research designs, which in turn need to be matched to a specific statistical test(s). Discursive paper. This paper discusses the issues relating to the selection of the most appropriate statistical test and makes some recommendations as to how these might be dealt with. When conducting empirical quantitative studies, a number of key issues need to be considered. Considerations for selecting the most appropriate statistical tests are discussed and flow charts provided to facilitate this process. When nursing clinicians and researchers conduct quantitative research studies, it is crucial that the most appropriate statistical test is selected to enable valid conclusions to be made. © 2013 John Wiley & Sons Ltd.

Development of deployable structures for large space platform systems. Volume 1: Executive summary

NASA Technical Reports Server (NTRS)

Greenberg, H. S.

1983-01-01

The preponderance of study effort was devoted toward the deployable platform systems study which culminated in the detailed design of a ground test article for future development testing. This design is representative of a prototype square-truss, single-fold building-block design that can construct deployable platform structures. This prototype design was selected through a comprehensive and traceable selection process applied to eight competitive designs. The selection process compared the competitive designs according to seven major selection criteria, i.e., design versatility, cost, thermal stability, meteoroid impact significance, reliability, performance predictability, and orbiter integration suitability. In support of the foregoing, a materials data base, and platform systems technology development needs were established. An erectable design of an OTV hangar was selected and recommended for further design development. This design was selected from five study-developed competitive single-fold and double-fold designs including hard-shell and inflatable designs. Also, two deployable manned module configurations, i.e., a hard-shell and an inflatable design were each developed to the same requirements as the composite of two Space station baseline habitat modules.

The development of memory efficiency and value-directed remembering across the life span: a cross-sectional study of memory and selectivity.

PubMed

Castel, Alan D; Humphreys, Kathryn L; Lee, Steve S; Galván, Adriana; Balota, David A; McCabe, David P

2011-11-01

Although attentional control and memory change considerably across the life span, no research has examined how the ability to strategically remember important information (i.e., value-directed remembering) changes from childhood to old age. The present study examined this in different age groups across the life span (N = 320, 5-96 years old). A selectivity task was used in which participants were asked to study and recall items worth different point values in order to maximize their point score. This procedure allowed for measures of memory quantity/capacity (number of words recalled) and memory efficiency/selectivity (the recall of high-value items relative to low-value items). Age-related differences were found for memory capacity, as young adults recalled more words than the other groups. However, in terms of selectivity, younger and older adults were more selective than adolescents and children. The dissociation between these measures across the life span illustrates important age-related differences in terms of memory capacity and the ability to selectively remember high-value information.

Preclinical pharmacology of bilastine, a new selective histamine H1 receptor antagonist: receptor selectivity and in vitro antihistaminic activity.

PubMed

Corcóstegui, Reyes; Labeaga, Luis; Innerárity, Ana; Berisa, Agustin; Orjales, Aurelio

2005-01-01

This study aimed to establish the receptor selectivity and antihistaminic activity of bilastine, a new selective antihistamine receptor antagonist. In vitro experiments were conducted using a receptor binding screening panel and guinea-pig and rat tissues. Antihistaminic activity was determined using H1 receptor binding studies and in vitro H1 antagonism studies conducted in guinea-pig tissues and human cell lines. Receptor selectivity was established using a receptor binding screening panel and a receptor antagonism screening conducted in guinea-pig, rat and rabbit tissues. Inhibition of inflammatory mediators was determined through the Schultz-Dale reaction in sensitised guinea-pig ileum. Bilastine binds to histamine H1-receptors as indicated by its displacement of [3H]-pyrilamine from H1-receptors expressed in guinea-pig cerebellum and human embryonic kidney (HEK) cell lines. The studies conducted on guinea-pig smooth muscle demonstrated the capability of bilastine to antagonise H1-receptors. Bilastine is selective for histamine H1-receptors as shown in receptor-binding screening conducted to determine the binding capacity of bilastine to 30 different receptors. The specificity of its H1-receptor antagonistic activity was also demonstrated in a series of in vitro experiments conducted on guinea-pig and rat tissues. The results of these studies confirmed the lack of significant antagonism against serotonin, bradykinin, leukotriene D4, calcium, muscarinic M3-receptors, alpha1-adrenoceptors, beta2-adrenoceptors, and H2- and H3-receptors. The results of the in vitro Schultz-Dale reaction demonstrated that bilastine also has anti-inflammatory activity. These preclinical studies provide evidence that bilastine has H1- antihistamine activity, with high specificity for H1-receptors, and poor or no affinity for other receptors. Bilastine has also been shown to have anti-inflammatory properties.

Study on site selection of cold chain logistics in northwest territories

NASA Astrophysics Data System (ADS)

Liu, Yubin; Ren, Zongwei

2017-08-01

In this research, we mainly studied the Site selection problem of cold chain logistics in northwest of China. In the first place, we counted the demands of cold chain products in northwest territories, and then classified it into the Site selection problem in five provinces in northwest territories(Xinjiang, Qinghai, Gansu, Ningxia, Shanxi); Next, we used the Center of gravity Method to select initial location; Finally, we established the location of distribution by using Analytic Hierarchy Process (AHP)and fuzzy comprehensive evaluation method. Comparing with the traditional method, this method not only considered the cost of transportation and distance, but also deliberated the physical condition, social environment and economics condition which associated with Site selection problem.

Changes in Food Selectivity in Children with Autism Spectrum Disorder.

PubMed

Bandini, Linda G; Curtin, Carol; Phillips, Sarah; Anderson, Sarah E; Maslin, Melissa; Must, Aviva

2017-02-01

Food selectivity is a common problem in children with autism spectrum disorder (ASD) and has an adverse impact on nutrient adequacy and family mealtimes. Despite recent research in this area, few studies have addressed whether food selectivity present in children with ASD persists into adolescence. In this study, we assessed food selectivity in 18 children with ASD at two time points (mean age = 6.8 and 13.2 years), and examined changes in food selectivity. While food refusal improved overall, we did not observe an increase in food repertoire (number of unique foods eaten). These findings support the need for interventions early in childhood to increase variety and promote healthy eating among children with ASD.

Do health technology assessments comply with QUOROM diagram guidance? An empirical study.

PubMed

Hind, Daniel; Booth, Andrew

2007-11-20

The Quality of Reporting of Meta-analyses (QUOROM) statement provides guidance for improving the quality of reporting of systematic reviews and meta-analyses. To make the process of study selection transparent it recommends "a flow diagram providing information about the number of RCTs identified, included, and excluded and the reasons for excluding them". We undertook an empirical study to identify the extent of compliance in the UK Health Technology Assessment (HTA) programme. We searched Medline to retrieve all systematic reviews of therapeutic interventions in the HTA monograph series published from 2001 to 2005. Two researchers recorded whether each study contained a meta-analysis of controlled trials, whether a QUOROM flow diagram was presented and, if so, whether it expressed the relationship between the number of citations and the number of studies. We used Cohen's kappa to test inter-rater reliability. 87 systematic reviews were retrieved. There was good and excellent inter-rater reliability for, respectively, whether a review contained a meta-analysis and whether each diagram contained a citation-to-study relationship. 49% of systematic reviews used a study selection flow diagram. When only systematic reviews containing a meta-analysis were analysed, compliance was only 32%. Only 20 studies (23% of all systematic reviews; 43% of those having a study selection diagram) had a diagram which expressed the relationship between citations and studies. Compliance with the recommendations of the QUOROM statement is not universal in systematic reviews or meta-analyses. Flow diagrams make the conduct of study selection transparent only if the relationship between citations and studies is clearly expressed. Reviewers should understand what they are counting: citations, papers, studies and trials are fundamentally different concepts which should not be confused in a diagram.

In vitro selection of catalytic RNAs

NASA Technical Reports Server (NTRS)

Chapman, K. B.; Szostak, J. W.

1994-01-01

In vitro selection techniques are poised to allow a rapid expansion of the study of catalysis by RNA enzymes (ribozymes). This truly molecular version of genetics has already been applied to the study of the structures of known ribozymes and to the tailoring of their catalytic activity to meet specific requirements of substrate specificity or reaction conditions. During the past year, in vitro selection has been successfully used to isolate novel RNA catalysts from random sequence pools.

Study directed at development of an implantable biotelemetry ion detector

NASA Technical Reports Server (NTRS)

Hanley, L. D.; Kress, D.

1971-01-01

A literature search was conducted to currently update known information in the field of ion-selective electrodes. The review attempts to identify present trends in cation and anions selective electrodes pertinent to the area of bioimplantable units. An electronic circuit was designed to provide the high impedance interface between the ion-selective sensors and signal-processing equipment. The resulting design emphasized the need for low power and miniaturization. Many of the circuits were constructed and used to evaluate the ion-selective electrodes. A cuvette capable of holding the ion-selective and the reference electrodes was designed and constructed. This equipment was used to evaluate commercially available ion-selective electrodes and the electrodes designed and constructed in the study. The results of the electrode tests are included.

"What Do They Want Me To Say?" The hidden curriculum at work in the medical school selection process: a qualitative study

PubMed Central

2012-01-01

Background There has been little study of the role of the essay question in selection for medical school. The purpose of this study was to obtain a better understanding of how applicants approached the essay questions used in selection at our medical school in 2007. Methods The authors conducted a qualitative analysis of 210 essays written as part of the medical school admissions process, and developed a conceptual framework to describe the relationships, ideas and concepts observed in the data. Results Findings of this analysis were confirmed in interviews with applicants and assessors. Analysis revealed a tension between "genuine" and "expected" responses that we believe applicants experience when choosing how to answer questions in the admissions process. A theory named "What do they want me to say?" was developed to describe the ways in which applicants modulate their responses to conform to their expectations of the selection process; the elements of this theory were confirmed in interviews with applicants and assessors. Conclusions This work suggests the existence of a "hidden curriculum of admissions" and demonstrates that the process of selection has a strong influence on applicant response. This paper suggests ways that selection might be modified to address this effect. Studies such as this can help us to appreciate the unintended consequences of admissions processes and can identify ways to make the selection process more consistent, transparent and fair. PMID:22448658

Kenya Quaker Secondary School Peace Curriculum Pilot Project: Examining the Role of the Principal in the Successes and Challenges of the Implementation

ERIC Educational Resources Information Center

Hockett, Eloise

2015-01-01

This qualitative study examined the implementation of a peace curriculum for Kenyan Quaker secondary schools. Fourteen schools were selected for this study 1 year after school leaders attended specific training sessions. On site visits were made to 12 of the 14 schools selected for this study, and interviews conducted with the remaining…

How Teacher Selection Practices in a High-Resource, Low-Need Suburban School District Compare with Best Practice Research: A Case Study

ERIC Educational Resources Information Center

Pease, Adam Steven

2012-01-01

The purpose of this study was to develop best practice standards for hiring public school teachers. This standard was developed from the available literature on recruiting, screening, selecting, and hiring high-quality teachers. The targeted and actual hiring processes of a case study district were compared to this teacher hiring standard.…

Mars Rover Sample Return mission

NASA Technical Reports Server (NTRS)

Bourke, Roger D.; Kwok, Johnny H.; Friedlander, Alan

1989-01-01

To gain a detailed understanding of the character of the planet Mars, it is necessary to send vehicle to the surface and return selected samples for intensive study in earth laboratories. Toward that end, studies have been underway for several years to determine the technically feasible means for exploring the surface and returning selected samples. This paper describes several MRSR mission concepts that have emerged from the most recent studies.

The Mentoring Experience of Nontraditional Students: A Case Study in Higher Education

ERIC Educational Resources Information Center

Langer, Arthur

2008-01-01

The purpose of this study was to select an institution that has mandated mentoring as part of its mission and to examine students' perceptions of the mentoring they received. The study selected Empire State College (ESC), a college that is part of the State of New York University system in the USA. ESC is an institution with a 36-year history of…

Modeling Student Performance in Mathematics Using Binary Logistic Regression at Selected Secondary Schools a Case Study of Mtwara Municipality and Ilemela District

ERIC Educational Resources Information Center

Mabula, Salyungu

2015-01-01

This study investigated the performance of secondary school students in Mathematics at the Selected Secondary Schools in Mtwara Municipality and Ilemela District by Absenteeism, Conduct, Type of School and Gender as explanatory Factors. The data used in the study was collected from documented records of 250 form three students with 1:1 gender…

Examining the Effects of State High School Exit Exam Policies on Selected Outcomes of Students with Disabilities

ERIC Educational Resources Information Center

Wilkinson, Tracy Gail

2012-01-01

This study had several purposes. The first purpose of the study was to examine the relationship between selected student, family and school characteristics, and state exit exam policies and the impact on graduation from high school among a sample of students with disabilities. A second purpose of the study was to explore the relationship between…

Site Selection in School District Research: A Measure of Effectiveness Using Hierarchical Longitudinal Growth Models of Performance

ERIC Educational Resources Information Center

Bowers, Alex J.

2015-01-01

School districts in the USA are an active area of study in education research as findings have shown that some districts find success in certain contexts while others struggle. However, the research domain has had few actionable methods for site selection for in-depth qualitative studies. This study analyses all districts in the state of Ohio (n =…

The Impact Analysis of Psychological Reliability of Population Pilot Study for Selection of Particular Reliable Multi-Choice Item Test in Foreign Language Research Work

ERIC Educational Resources Information Center

Fazeli, Seyed Hossein

2010-01-01

The purpose of research described in the current study is the psychological reliability, its importance, application, and more to investigate on the impact analysis of psychological reliability of population pilot study for selection of particular reliable multi-choice item test in foreign language research work. The population for subject…

Summary Report of National Study of Word Processing Installations in Selected Business Organizations. A Summary of a Report on the National Word Processing Research Study of Delta Pi Epsilon.

ERIC Educational Resources Information Center

Scriven, Jolene D.; And Others

A study sought to determine current practices in word processing installations located in selected organizations throughout the United States. A related problem was to ascertain anticipated future developments in word processing to provide information for educational institutions preparing workers for the business office. Six interview instruments…

Lessons in Success: A Multi-Campus Study of Factors Influencing Academic Accomplishment among High-Achieving African American Students at Private Liberal Arts Colleges

ERIC Educational Resources Information Center

Johnson, Ryan A.

2013-01-01

The purpose of this study was to explore the academic experiences of highly successful African-American male graduates of small, private liberal arts colleges using a qualitative approach. Fourteen highly successful alumni from selective, private colleges were purposefully selected for the study, including seven African-American males and seven…

College Climate and Teacher-Trainee's Academic Work in Selected Colleges of Education in the Ashanti Region of Ghana

ERIC Educational Resources Information Center

Adjei, Augustine; Dontoh, Samuel; Baafi-Frimpong, Stephen

2017-01-01

The study aimed at investigating the extent to which College climate (Leadership roles/practices and Class size) impact on academic work of Teacher-trainees. A survey research design was used for the study because it involved a study of relatively large population who were purposively and randomly selected. A sample size of 322 out of the…

The Management of University-Industry Relations: Five Institutional Case Studies from Africa, Europe, Latin America, and the Pacific Region. Improving the Managerial Effectiveness of Higher Education Institutions.

ERIC Educational Resources Information Center

Martin, Michaela, Ed.

Five case studies were conducted to collect empirical evidence on innovative mechanisms through which universities worldwide manage their relations with industry. Cases were selected from institutions of higher education in Israel, Papua New Guinea, Turkey, Brazil, and Uganda. These studies were selected for their innovative approaches, but also…

A Comparative Study of Identity Styles, Quality of Life and Behavioral Problems between Single Parent and Two Parent Adolescents

ERIC Educational Resources Information Center

Abedini, Zoleykha; Mirnasab, Mirmahmoud; Fathi Azar, Eskander

2017-01-01

The present study aimed to investigate identity styles, quality of life and behavioral difficulties between adolescents with single and two-parent status. In this causal- comparative study, a total of 214 high school students were selected, then 112 single parent students (59 females and 53 males) were selected by the voluntary response sampling…

Influence of Learning Environment on Students' Academic Achievement in Mathematics: A Case Study of Some Selected Secondary Schools in Yobe State-Nigeria

ERIC Educational Resources Information Center

Shamaki, Timothy Ado

2015-01-01

The purpose of the study was to determine the influence of learning environment on students' academic achievement in mathematics at senior secondary school level. Thus the study investigated some components of learning environment and their possible influence on students' academic achievement in mathematics. A sample of 337 randomly selected SS II…

Enhancing Students' Attitude towards Nigerian Senior Secondary School Physics through the Use of Cooperative, Competitive and Individualistic Learning Strategies

ERIC Educational Resources Information Center

Akinbobola, Akinyemi Olufunminiyi

2009-01-01

The study was conducted to find out the attitude of students towards the use of cooperative, competitive and individualistic learning strategies in Nigerian senior secondary school physics. The design selected for this study was quasi-experimental. A total of 140 students took part in the study and they were selected by a random sampling…

A Case Study of Human Resource Development Professionals' Decision Making in Vendor Selection for Employee Development: A Degrees-of-Freedom Analysis

ERIC Educational Resources Information Center

Cathcart, Stephen Michael

2016-01-01

This mixed method study examines HRD professionals' decision-making processes when making an organizational purchase of training. The study uses a case approach with a degrees of freedom analysis. The data to analyze will examine how HRD professionals in manufacturing select outside vendors human resource development programs for training,…

An Evaluation of a Progressive High-Probability Instructional Sequence Combined with Low-Probability Demand Fading in the Treatment of Food Selectivity

ERIC Educational Resources Information Center

Penrod, Becky; Gardella, Laura; Fernand, Jonathan

2012-01-01

Few studies have examined the effects of the high-probability instructional sequence in the treatment of food selectivity, and results of these studies have been mixed (e.g., Dawson et al., 2003; Patel et al., 2007). The present study extended previous research on the high-probability instructional sequence by combining this procedure with…

Pharmacist intervention in patient selection of nonprescription and self-care products.

PubMed

Schimmelfing, John Taylor; Brookhart, Andrea L; Fountain, K Michele Brown; Goode, Jean-Venable Kelly R

To evaluate the potential outcomes of pharmacist intervention on patient selection of nonprescription and self-care products and to evaluate patient confidence and satisfaction with the assistance of the pharmacist. A prospective, convenience sample study was conducted at 3 locations of a national supermarket chain pharmacy in the Charlottesville, Virginia, area over 4 months. Patients were recruited for the study if they approached the pharmacy counter and requested assistance with nonprescription and self-care product selection or if the investigating pharmacists approached the patient in the self-care aisles. Men and nonpregnant women age 18 years and older were included in the study. Patients self-selected into the study by agreeing to participate in the study intervention and answering questions relating to their experience with the pharmacist consultation. The study intervention was the pharmacist consultation with the patient to assess the self-care complaint and to make an appropriate recommendation. Forty-two patients participated, the mean (±SD) age was 57 ± 20.8 years, and 62% of patients were female. Sixty percent of patients had used pharmacist help in the past in selecting nonprescription and self-care products. There were 87 total potential outcomes, and a mean of 2.1 potential outcomes per patient. The most potential common outcomes were reduced drug cost, avoided physician visit, corrected product use, and avoided a new prescription. Mean patient confidence (±SD) was 4.38 ± 0.96. Mean patient satisfaction was 4.98. Every patient (100%) stated that they would be more willing to ask for pharmacist help in the future with self-care product selection. The mean encounter time was 6 minutes. Pharmacists' active involvement in patient self-care consultation may help patients to select the most effective and safe product and improve patient outcomes. Patients are highly satisfied with pharmacists' help with the selection of nonprescription and self-care products and are more confident with future self-treatment. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Is sexual selection driving diversification of the bioluminescent ponyfishes (Teleostei: Leiognathidae)?

PubMed

Chakrabarty, Prosanta; Davis, Matthew P; Smith, W Leo; Baldwin, Zachary H; Sparks, John S

2011-07-01

Sexual selection may facilitate genetic isolation among populations and result in increased rates of diversification. As a mechanism driving diversification, sexual selection has been invoked and upheld in numerous empirical studies across disparate taxa, including birds, plants and spiders. In this study, we investigate the potential impact of sexual selection on the tempo and mode of ponyfish evolution. Ponyfishes (Leiognathidae) are bioluminescent marine fishes that exhibit sexually dimorphic features of their unique light-organ system (LOS). Although sexual selection is widely considered to be the driving force behind ponyfish speciation, this hypothesis has never been formally tested. Given that some leiognathid species have a sexually dimorphic LOS, whereas others do not, this family provides an excellent system within which to study the potential role of sexual selection in diversification and morphological differentiation. In this study, we estimate the phylogenetic relationships and divergence times for Leiognathidae, investigate the tempo and mode of ponyfish diversification, and explore morphological shape disparity among leiognathid clades. We recover strong support for a monophyletic Leiognathidae and estimate that all major ponyfish lineages evolved during the Paleogene. Our studies of ponyfish diversification demonstrate that there is no conclusive evidence that sexually dimorphic clades are significantly more species rich than nonsexually dimorphic lineages and that evidence is lacking to support any significant diversification rate increases within ponyfishes. Further, we detected a lineage-through-time signal indicating that ponyfishes have continuously diversified through time, which is in contrast to many recent diversification studies that identify lineage-through-time patterns that support mechanisms of density-dependent speciation. Additionally, there is no evidence of sexual selection hindering morphological diversity, as sexually dimorphic taxa are shown to be more disparate in overall shape morphology than nonsexually dimorphic taxa. Our results suggest that if sexual selection is occurring in ponyfish evolution, it is likely acting only as a genetic isolating mechanism that has allowed ponyfishes to continuously diversify over time, with no overall impact on increases in diversification rate or morphological disparity. © 2011 Blackwell Publishing Ltd.

Selective Attention Deficits in High Test Anxious Children: A Failure to Replicate.

ERIC Educational Resources Information Center

Ford, Carol E.; And Others

1985-01-01

Results of a study involving 5 high test-anxious poor readers failed to replicate an earlier study reporting selective attention deficits in the population. Further, there was a marginal tendency for older poor readers to be high test-anxious. (Author/CL)

How motivation affects academic performance: a structural equation modelling analysis.

PubMed

Kusurkar, R A; Ten Cate, Th J; Vos, C M P; Westers, P; Croiset, G

2013-03-01

Few studies in medical education have studied effect of quality of motivation on performance. Self-Determination Theory based on quality of motivation differentiates between Autonomous Motivation (AM) that originates within an individual and Controlled Motivation (CM) that originates from external sources. To determine whether Relative Autonomous Motivation (RAM, a measure of the balance between AM and CM) affects academic performance through good study strategy and higher study effort and compare this model between subgroups: males and females; students selected via two different systems namely qualitative and weighted lottery selection. Data on motivation, study strategy and effort was collected from 383 medical students of VU University Medical Center Amsterdam and their academic performance results were obtained from the student administration. Structural Equation Modelling analysis technique was used to test a hypothesized model in which high RAM would positively affect Good Study Strategy (GSS) and study effort, which in turn would positively affect academic performance in the form of grade point averages. This model fit well with the data, Chi square = 1.095, df = 3, p = 0.778, RMSEA model fit = 0.000. This model also fitted well for all tested subgroups of students. Differences were found in the strength of relationships between the variables for the different subgroups as expected. In conclusion, RAM positively correlated with academic performance through deep strategy towards study and higher study effort. This model seems valid in medical education in subgroups such as males, females, students selected by qualitative and weighted lottery selection.

Causation or selection - examining the relation between education and overweight/obesity in prospective observational studies: a meta-analysis.

PubMed

Kim, T J; Roesler, N M; von dem Knesebeck, O

2017-06-01

Numerous studies have investigated the association between education and overweight/obesity. Yet less is known about the relative importance of causation (i.e. the influence of education on risks of overweight/obesity) and selection (i.e. the influence of overweight/obesity on the likelihood to attain education) hypotheses. A systematic review was performed to assess the linkage between education and overweight/obesity in prospective studies in general populations. Studies were searched within five databases, and study quality was appraised with the Newcastle-Ottawa scale. In total, 31 studies were considered for meta-analysis. Regarding causation (24 studies), the lower educated had a higher likelihood (odds ratio: 1.33, 1.21-1.47) and greater risk (risk ratio: 1.34, 1.08-1.66) for overweight/obesity, when compared with the higher educated. However, these associations were no longer statistically significant when accounting for publication bias. Concerning selection (seven studies), overweight/obese individuals had a greater likelihood of lower education (odds ratio: 1.57, 1.10-2.25), when contrasted with the non-overweight or non-obese. Subgroup analyses were performed by stratifying meta-analyses upon different factors. Relationships between education and overweight/obesity were affected by study region, age groups, gender and observation period. In conclusion, it is necessary to consider both causation and selection processes in order to tackle educational inequalities in obesity appropriately. © 2017 World Obesity Federation.

The Hamburg Selection Procedure for Dental Students – Introduction of the HAM-Nat as subject-specific test for study aptitude

PubMed Central

Kothe, Christian; Hissbach, Johanna; Hampe, Wolfgang

2013-01-01

Introduction: The present study examines the question whether the selection of dental students should be based solely on average school-leaving grades (GPA) or whether it could be improved by using a subject-specific aptitude test. Methods: The HAM-Nat Natural Sciences Test was piloted with freshmen during their first study week in 2006 and 2007. In 2009 and 2010 it was used in the dental student selection process. The sample size in the regression models varies between 32 and 55 students. Results: Used as a supplement to the German GPA, the HAM-Nat test explained up to 12% of the variance in preclinical examination performance. We confirmed the prognostic validity of GPA reported in earlier studies in some, but not all of the individual preclinical examination results. Conclusion: The HAM-Nat test is a reliable selection tool for dental students. Use of the HAM-Nat yielded a significant improvement in prediction of preclinical academic success in dentistry. PMID:24282449

Microstructure of a black chrome solar selective absorber

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

Lampert, C.M.

1978-08-01

The structure of Harshaw Chemicals' CHROM-ONYX type of black chrome/metal selective absorber was studied to gain a better understanding of its influence upon the mechanism of wavelength selectivity. Spectral reflectance measurements were performed on seven samples. In this study, the best selectivity was found by these measurements to be 1.0 micron of black chrome on copper and 0.7 micron of black chrome on nickel. Both transmission and scanning electron microscopy were employed to study microstructure and chemical composition. As a result of the combined studies, some effects of black chrome thickness and the metallic substrate were determined. It was foundmore » that black chrome consisted of a very fine metallic distribution of particles of chromium, possibly suspended within a matrix of an oxide of chromium. This combination was, in turn, agglomerated into larger particles within the 0.05--0.3 micron size range. These larger particles formed a network which constituted the surface coating.« less

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

PubMed

Vasconcellos, Mauricio Teixeira Leite de; Silva, Pedro Luis do Nascimento; Szklo, Moyses; Kuschnir, Maria Cristina Caetano; Klein, Carlos Henrique; Abreu, Gabriela de Azevedo; Barufaldi, Laura Augusta; Bloch, Katia Vergetti

2015-05-01

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

Molecular Dynamics Simulation Study of the Selectivity of a Silica Polymer for Ibuprofen

PubMed Central

Concu, Riccardo; Cordeiro, M. Natalia D. S.

2016-01-01

In the past few years, the sol-gel polycondensation technique has been increasingly employed with great success as an alternative approach to the preparation of molecularly imprinted materials (MIMs). The main aim of this study was to study, through a series of molecular dynamics (MD) simulations, the selectivity of an imprinted silica xerogel towards a new template—the (±)-2-(P-Isobutylphenyl) propionic acid (Ibuprofen, IBU). We have previously demonstrated the affinity of this silica xerogel toward a similar molecule. In the present study, we simulated the imprinting process occurring in a sol-gel mixture using the Optimized Potentials for Liquid Simulations-All Atom (OPLS-AA) force field, in order to evaluate the selectivity of this xerogel for a template molecule. In addition, for the first time, we have developed and verified a new parameterisation for the Ibuprofen® based on the OPLS-AA framework. To evaluate the selectivity of the polymer, we have employed both the radial distribution functions, interaction energies and cluster analyses. PMID:27399685

Molecular Dynamics Simulation Study of the Selectivity of a Silica Polymer for Ibuprofen.

PubMed

Concu, Riccardo; Cordeiro, M Natalia D S

2016-07-07

In the past few years, the sol-gel polycondensation technique has been increasingly employed with great success as an alternative approach to the preparation of molecularly imprinted materials (MIMs). The main aim of this study was to study, through a series of molecular dynamics (MD) simulations, the selectivity of an imprinted silica xerogel towards a new template-the (±)-2-(P-Isobutylphenyl) propionic acid (Ibuprofen, IBU). We have previously demonstrated the affinity of this silica xerogel toward a similar molecule. In the present study, we simulated the imprinting process occurring in a sol-gel mixture using the Optimized Potentials for Liquid Simulations-All Atom (OPLS-AA) force field, in order to evaluate the selectivity of this xerogel for a template molecule. In addition, for the first time, we have developed and verified a new parameterisation for the Ibuprofen(®) based on the OPLS-AA framework. To evaluate the selectivity of the polymer, we have employed both the radial distribution functions, interaction energies and cluster analyses.

Evolution in population parameters: density-dependent selection or density-dependent fitness?

PubMed

Travis, Joseph; Leips, Jeff; Rodd, F Helen

2013-05-01

Density-dependent selection is one of earliest topics of joint interest to both ecologists and evolutionary biologists and thus occupies an important position in the histories of these disciplines. This joint interest is driven by the fact that density-dependent selection is the simplest form of feedback between an ecological effect of an organism's own making (crowding due to sustained population growth) and the selective response to the resulting conditions. This makes density-dependent selection perhaps the simplest process through which we see the full reciprocity between ecology and evolution. In this article, we begin by tracing the history of studying the reciprocity between ecology and evolution, which we see as combining the questions of evolutionary ecology with the assumptions and approaches of ecological genetics. In particular, density-dependent fitness and density-dependent selection were critical concepts underlying ideas about adaptation to biotic selection pressures and the coadaptation of interacting species. However, theory points to a critical distinction between density-dependent fitness and density-dependent selection in their influences on complex evolutionary and ecological interactions among coexisting species. Although density-dependent fitness is manifestly evident in empirical studies, evidence of density-dependent selection is much less common. This leads to the larger question of how prevalent and important density-dependent selection might really be. Life-history variation in the least killifish Heterandria formosa appears to reflect the action of density-dependent selection, and yet compelling evidence is elusive, even in this well-studied system, which suggests some important challenges for understanding density-driven feedbacks between ecology and evolution.

Rainbow Plasmonic Nanobubbles: Synergistic Activation of Gold Nanoparticle Clusters

PubMed Central

Lukianova-Hleb, Ekaterina Y; Oginsky, Alexander O; Shenefelt, Derek L; Drezek, Rebekah A; Hafner, Jason H; Farach-Carson, Mary C; Lapotko, Dmitri O

2011-01-01

The synergistic physical and biological effects of selective targeting and activation of plasmonic nanoparticles were studied for a transient vapor nanobubble mode. Simultaneous optical activation of two plasmon resonances in multi-nanoparticle clusters significantly improved the selectivity and efficacy of the nanobubble generation through and was termed “rainbow plasmonic nanobubbles.” The rainbow nanobubble mechanism has been studied in water and in living cells in vitro. This mechanism provided maximal selectivity of the nanobubble generation in both models and therefore, can the therapeutic selectivity and optical contrast of gold nanoparticles in a heterogeneous physiological microenvironment at cell level. PMID:21804947

Relations between 18-month-olds' gaze pattern and target action performance: a deferred imitation study with eye tracking.

PubMed

Óturai, Gabriella; Kolling, Thorsten; Knopf, Monika

2013-12-01

Deferred imitation studies are used to assess infants' declarative memory performance. These studies have found that deferred imitation performance improves with age, which is usually attributed to advancing memory capabilities. Imitation studies, however, are also used to assess infants' action understanding. In this second research program it has been observed that infants around the age of one year imitate selectively, i.e., they imitate certain kinds of target actions and omit others. In contrast to this, two-year-olds usually imitate the model's exact actions. 18-month-olds imitate more exactly than one-year-olds, but more selectively than two-year-olds, a fact which makes this age group especially interesting, since the processes underlying selective vs. exact imitation are largely debated. The question, for example, if selective attention to certain kinds of target actions accounts for preferential imitation of these actions in young infants is still open. Additionally, relations between memory capabilities and selective imitation processes, as well as their role in shaping 18-month-olds' neither completely selective, nor completely exact imitation have not been thoroughly investigated yet. The present study, therefore, assessed 18-month-olds' gaze toward two types of actions (functional vs. arbitrary target actions) and the model's face during target action demonstration, as well as infants' deferred imitation performance. Although infants' fixation times to functional target actions were not longer than to arbitrary target actions, they imitated the functional target actions more frequently than the arbitrary ones. This suggests that selective imitation does not rely on selective gaze toward functional target actions during the demonstration phase. In addition, a post hoc analysis of interindividual differences suggested that infants' attention to the model's social-communicative cues might play an important role in exact imitation, meaning the imitation of both functional and arbitrary target actions. Copyright © 2013 Elsevier Inc. All rights reserved.

Eyes wide open: enhanced pupil dilation when selectively studying important information.

PubMed

Ariel, Robert; Castel, Alan D

2014-01-01

Remembering important information is imperative for efficient memory performance, but it is unclear how we encode important information. The current experiment evaluated two non-exclusive hypotheses for how learners selectively encode important information at the expense of less important information (differential resource allocation and information reduction). To evaluate these hypotheses, we measured changes in learners' pupil diameter and fixation durations while participants performed a selectivity task that involved studying lists consisting of words associated with different point values. Participants were instructed to maximize their score on a free recall task that they completed after studying each list. Participants' pupils dilated more when studying high-valued than low-valued words, and these changes were associated with better memory for high-valued words. However, participants fixated equally on words regardless of their value, which is inconsistent with the information reduction hypothesis. Participants also increased their memory selectivity across lists, but changes in pupil diameter and differences in fixations could not account for this increased selectivity. The results suggest that learners allocate attention differently to items as a function of their value, and that multiple processes and operations contribute to value-directed remembering.

Eyes Wide Open: Enhanced Pupil Dilation When Selectively Studying Important Information

PubMed Central

Ariel, Robert; Castel, Alan D.

2013-01-01

Remembering important information is imperative for efficient memory performance, but it is unclear how we encode important information. The current experiment evaluated two non-exclusive hypotheses for how learners selectively encode important information at the expense of less important information (differential resource allocation and information reduction). To evaluate these hypotheses, we measured changes in learners’ pupil diameter and fixation durations while participants performed a selectivity task that involved studying lists consisting of words associated with different point values. Participants were instructed to maximize their score on a free recall task that they completed after studying each list. Participants’ pupils dilated more when studying high-valued than low-valued words, and these changes were associated with better memory for high-valued words. However, participants fixated equally on words regardless of their value, which is inconsistent with the information reduction hypothesis. Participants also increased their memory selectivity across lists, but changes in pupil diameter and differences in fixations could not account for this increased selectivity. The results suggest that learners allocate attention differently to items as a function of their value, and that multiple processes and operations contribute to value-directed remembering. PMID:24162863

Gendered races: implications for interracial marriage, leadership selection, and athletic participation.

PubMed

Galinsky, Adam D; Hall, Erika V; Cuddy, Amy J C

2013-04-01

Six studies explored the overlap between racial and gender stereotypes, and the consequences of this overlap for interracial dating, leadership selection, and athletic participation. Two initial studies captured the explicit and implicit gender content of racial stereotypes: Compared with the White stereotype, the Asian stereotype was more feminine, whereas the Black stereotype was more masculine. Study 3 found that heterosexual White men had a romantic preference for Asians over Blacks and that heterosexual White women had a romantic preference for Blacks over Asians; preferences for masculinity versus femininity mediated participants' attraction to Blacks relative to Asians. The pattern of romantic preferences observed in Study 3 was replicated in Study 4, an analysis of the data on interracial marriages from the 2000 U.S. Census. Study 5 showed that Blacks were more likely and Asians less likely than Whites to be selected for a masculine leadership position. In Study 6, an analysis of college athletics showed that Blacks were more heavily represented in more masculine sports, relative to Asians. These studies demonstrate that the gender content of racial stereotypes has important real-world consequences.

Genome-wide scans for loci under selection in humans

PubMed Central

2005-01-01

Natural selection, which can be defined as the differential contribution of genetic variants to future generations, is the driving force of Darwinian evolution. Identifying regions of the human genome that have been targets of natural selection is an important step in clarifying human evolutionary history and understanding how genetic variation results in phenotypic diversity, it may also facilitate the search for complex disease genes. Technological advances in high-throughput DNA sequencing and single nucleotide polymorphism genotyping have enabled several genome-wide scans of natural selection to be undertaken. Here, some of the observations that are beginning to emerge from these studies will be reviewed, including evidence for geographically restricted selective pressures (ie local adaptation) and a relationship between genes subject to natural selection and human disease. In addition, the paper will highlight several important problems that need to be addressed in future genome-wide studies of natural selection. PMID:16004726

Mental health courts and their selection processes: modeling variation for consistency.

PubMed

Wolff, Nancy; Fabrikant, Nicole; Belenko, Steven

2011-10-01

Admission into mental health courts is based on a complicated and often variable decision-making process that involves multiple parties representing different expertise and interests. To the extent that eligibility criteria of mental health courts are more suggestive than deterministic, selection bias can be expected. Very little research has focused on the selection processes underpinning problem-solving courts even though such processes may dominate the performance of these interventions. This article describes a qualitative study designed to deconstruct the selection and admission processes of mental health courts. In this article, we describe a multi-stage, complex process for screening and admitting clients into mental health courts. The selection filtering model that is described has three eligibility screening stages: initial, assessment, and evaluation. The results of this study suggest that clients selected by mental health courts are shaped by the formal and informal selection criteria, as well as by the local treatment system.

Linear and nonlinear variable selection in competing risks data.

PubMed

Ren, Xiaowei; Li, Shanshan; Shen, Changyu; Yu, Zhangsheng

2018-06-15

Subdistribution hazard model for competing risks data has been applied extensively in clinical researches. Variable selection methods of linear effects for competing risks data have been studied in the past decade. There is no existing work on selection of potential nonlinear effects for subdistribution hazard model. We propose a two-stage procedure to select the linear and nonlinear covariate(s) simultaneously and estimate the selected covariate effect(s). We use spectral decomposition approach to distinguish the linear and nonlinear parts of each covariate and adaptive LASSO to select each of the 2 components. Extensive numerical studies are conducted to demonstrate that the proposed procedure can achieve good selection accuracy in the first stage and small estimation biases in the second stage. The proposed method is applied to analyze a cardiovascular disease data set with competing death causes. Copyright © 2018 John Wiley & Sons, Ltd.

Biologic therapies and bone loss in rheumatoid arthritis.

PubMed

Zerbini, C A F; Clark, P; Mendez-Sanchez, L; Pereira, R M R; Messina, O D; Uña, C R; Adachi, J D; Lems, W F; Cooper, C; Lane, N E

2017-02-01

Rheumatoid arthritis (RA) is a common systemic autoimmune disease of unknown cause, characterized by a chronic, symmetric, and progressive inflammatory polyarthritis. One of the most deleterious effects induced by the chronic inflammation of RA is bone loss. During the last 15 years, the better knowledge of the cytokine network involved in RA allowed the development of potent inhibitors of the inflammatory process classified as biological DMARDs. These new drugs are very effective in the inhibition of inflammation, but there are only few studies regarding their role in bone protection. The principal aim of this review was to show the evidence of the principal biologic therapies and bone loss in RA, focusing on their effects on bone mineral density, bone turnover markers, and fragility fractures. Using the PICOST methodology, two coauthors (PC, LM-S) conducted the search using the following MESH terms: rheumatoid arthritis, osteoporosis, clinical trials, TNF- antagonists, infliximab, adalimumab, etanercept, certolizumab, golimumab, IL-6 antagonists, IL-1 antagonists, abatacept, tocilizumab, rituximab, bone mineral density, bone markers, and fractures. The search was conducted electronically and manually from the following databases: Medline and Science Direct. The search period included articles from 2003 to 2015. The selection included only original adult human research written in English. Titles were retrieved and the same two authors independently selected the relevant studies for a full text. The retrieved selected studies were also reviewed completing the search for relevant articles. The first search included 904 titles from which 253 titles were selected. The agreement on the selection among researchers resulted in a Kappa statistic of 0.95 (p < 0.000). Only 248 abstracts evaluated were included in the acronym PICOST. The final selection included only 28 studies, derived from the systematic search. Additionally, a manual search in the bibliography of the selected articles was made and included into the text and into the section of "small molecules of new agents." Treatment with biologic drugs is associated with the decrease in bone loss. Studies with anti-TNF blocking agents show preservation or increase in spine and hip BMD and also a better profile of bone markers. Most of these studies were performed with infliximab. Only three epidemiological studies analyzed the effect on fractures after anti-TNF blocking agent's treatment. IL-6 blocking agents also showed improvement in localized bone loss not seen with anti-TNF agents. There are a few studies with rituximab and abatacept. Although several studies reported favorable actions of biologic therapies on bone protection, there are still unmet needs for studies regarding their actions on the risk of bone fractures.

Participation and Selection Effects of a Voluntary Selection Process

ERIC Educational Resources Information Center

Schripsema, Nienke R.; van Trigt, Anke M.; Lucieer, Susanna M.; Wouters, Anouk; Croiset, Gerda; Themmen, Axel P. N.; Borleffs, Jan C. C.; Cohen-Schotanus, Janke

2017-01-01

Many different medical school selection processes are used worldwide. In this paper, we examine the effect of (1) participation, and (2) selection in a voluntary selection process on study performance. We included data from two cohorts of medical students admitted to Erasmus MC, Rotterdam and VUmc, Amsterdam, The Netherlands and compared them to…

Bias Reduction in Quasi-Experiments with Little Selection Theory but Many Covariates

ERIC Educational Resources Information Center

Steiner, Peter M.; Cook, Thomas D.; Li, Wei; Clark, M. H.

2015-01-01

In observational studies, selection bias will be completely removed only if the selection mechanism is ignorable, namely, all confounders of treatment selection and potential outcomes are reliably measured. Ideally, well-grounded substantive theories about the selection process and outcome-generating model are used to generate the sample of…

Reciprocal selection causes a coevolutionary arms race between crossbills and lodgepole pine.

PubMed

Benkman, Craig W; Parchman, Thomas L; Favis, Amanda; Siepielski, Adam M

2003-08-01

Few studies have shown both reciprocal selection and reciprocal adaptations for a coevolving system in the wild. The goal of our study was to determine whether the patterns of selection on Rocky Mountain lodgepole pine (Pinus contorta spp. latifolia) and red crossbills (Loxia curvirostra complex) were concordant with earlier published evidence of reciprocal adaptations in lodgepole pine and crossbills on isolated mountain ranges in the absence of red squirrels (Tamiasciurus hudsonicus). We found that selection (directional) by crossbills on lodgepole pine where Tamiasciurus are absent was divergent from the selection (directional) exerted by Tamiasciurus on lodgepole pine. This resulted in divergent selection between areas with and without Tamiasciurus that was congruent with the geographic patterns of cone variation. In the South Hills, Idaho, where Tamiasciurus are absent and red crossbills are thought to be coevolving with lodgepole pine, crossbills experienced stabilizing selection on bill size, with cone structure as the agent of selection. These results show that crossbills and lodgepole pine exhibit reciprocal adaptations in response to reciprocal selection, and they provide insight into the traits mediating and responding to selection in a coevolutionary arms race.

The contributions of premating and postmating selection episodes to total selection in sex-role-reversed Gulf pipefish.

PubMed

Rose, Emily; Paczolt, Kimberly A; Jones, Adam G

2013-09-01

Empirical studies of sexual selection often focus on events occurring either before or after mating but rarely both and consequently may fail to discern the relative magnitudes and interactions of premating and postmating episodes of selection. Here, we simultaneously quantify premating and postmating selection in the sex-role-reversed Gulf pipefish by using a microsatellite-based analysis of parentage in experimental populations. Female pipefish exhibited an opportunity for selection (I) of 1.64, which was higher than that of males (0.35). Decompositions of I and the selection differential on body size showed that over 95% of the selection on females arose from the premating phase. We also found evidence for a trade-off between selection phases, where multiply mating females had significantly lower offspring survivorship compared to singly mated females. In males, variance in relative fitness arose mainly from the number of eggs received per copulation and a small number of males who failed to mate. Overall, our study exemplifies a general approach for the decomposition of total selection into premating and postmating phases to understand the interplay among components of natural and sexual selection that conspire to shape sexually selected traits.

EVOLUTION OF DIVERGENT FEMALE MATING PREFERENCE IN RESPONSE TO EXPERIMENTAL SEXUAL SELECTION

PubMed Central

Debelle, Allan; Ritchie, Michael G; Snook, Rhonda R

2014-01-01

Sexual selection is predicted to drive the coevolution of mating signals and preferences (mating traits) within populations, and could play a role in speciation if sexual isolation arises due to mating trait divergence between populations. However, few studies have demonstrated that differences in mating traits between populations result from sexual selection alone. Experimental evolution is a promising approach to directly examine the action of sexual selection on mating trait divergence among populations. We manipulated the opportunity for sexual selection (low vs. high) in populations of Drosophila pseudoobscura. Previous studies on these experimental populations have shown that sexual selection manipulation resulted in the divergence between sexual selection treatments of several courtship song parameters, including interpulse interval (IPI) which markedly influences male mating success. Here, we measure female preference for IPI using a playback design to test for preference divergence between the sexual selection treatments after 130 generations of experimental sexual selection. The results suggest that female preference has coevolved with male signal, in opposite directions between the sexual selection treatments, providing direct evidence of the ability of sexual selection to drive the divergent coevolution of mating traits between populations. We discuss the implications in the context sexual selection and speciation. PMID:24931497

Proceedings of the Conference on the Design of Experiments in Army Research Development and Testing (21st)

DTIC Science & Technology

1976-05-01

treatment groups are in the ctual treatment received. This requires comparability of patients as they are intered into study , managed when on study , and...at time of entry into study is to select patients for a control group according to certain characteristics, namely those which are known to influence...control group of B patients could be selected from the literature, chosen on a matched basis from previously or concurrently conducted clinical studies

Advanced turbocharger design study program

NASA Technical Reports Server (NTRS)

Culy, D. G.; Heldenbrand, R. W.; Richardson, N. R.

1984-01-01

The advanced Turbocharger Design Study consisted of: (1) the evaluation of three advanced engine designs to determine their turbocharging requirements, and of technologies applicable to advanced turbocharger designs; (2) trade-off studies to define a turbocharger conceptual design and select the engine with the most representative requirements for turbocharging; (3) the preparation of a turbocharger conceptual design for the Curtiss Wright RC2-32 engine selected in the trade-off studies; and (4) the assessment of market impact and the preparation of a technology demonstration plan for the advanced turbocharger.

Multiple-input multiple-output causal strategies for gene selection.

PubMed

Bontempi, Gianluca; Haibe-Kains, Benjamin; Desmedt, Christine; Sotiriou, Christos; Quackenbush, John

2011-11-25

Traditional strategies for selecting variables in high dimensional classification problems aim to find sets of maximally relevant variables able to explain the target variations. If these techniques may be effective in generalization accuracy they often do not reveal direct causes. The latter is essentially related to the fact that high correlation (or relevance) does not imply causation. In this study, we show how to efficiently incorporate causal information into gene selection by moving from a single-input single-output to a multiple-input multiple-output setting. We show in synthetic case study that a better prioritization of causal variables can be obtained by considering a relevance score which incorporates a causal term. In addition we show, in a meta-analysis study of six publicly available breast cancer microarray datasets, that the improvement occurs also in terms of accuracy. The biological interpretation of the results confirms the potential of a causal approach to gene selection. Integrating causal information into gene selection algorithms is effective both in terms of prediction accuracy and biological interpretation.

Implementation of Fuzzy Decision to Control Patient Room Facilities using Eye Blink

NASA Astrophysics Data System (ADS)

Zaeni, Ilham A. E.; Wibawa, Aji P.; Aripriharta; Sendari, Siti

2018-04-01

This study proposed the implementation of Fuzzy decision to control patient’s room facilities. In this study, four icons were sequentially displayed on the computer screen. The icons representing four option that can be selected by the patient is including switch the light on/off, switch the fan on/off, moving the bed’s backrest downward, and moving the bed’s backrest upward. The eye blink was extracted from subject’s electroencephalograph (EEG) signals which acquired from the FP1 region. The attention was also extracted from subject’s EEG signals to ensure that subject concentrate to the task. The eye blink and attention level were used for Fuzzy decision inputs, while the output is a decision that states the selection is valid or not. The selected option is the command that appears on the screen when the selection is valid. In this study, subjects were asked to choose each command several times and the accuracy was computed based on the number of correct selection.

The colour of fitness: plumage coloration and lifetime reproductive success in the tawny owl

PubMed Central

Brommer, Jon E; Ahola, Kari; Karstinen, Teuvo

2005-01-01

We studied variation in plumage colour and life history in a population of tawny owls (Strix aluco) in southern Finland, using 26 years of data on individually marked male and female owls. Colour was scored on a semi-continuous scale from pale grey to reddish brown. Colour scoring was repeatable and showed a bimodal distribution (grey and brown morph) in both sexes. During the study period, colour composition was stable in the study population in both sexes. The sexes did not mate assortatively with respect to their colour. Colour was a highly heritable trait and was under selection. Grey-coloured male and female owls had a higher lifetime production of fledglings, and grey-coloured male (but not female) owls produced more recruits during their lifetime than brown individuals. Selection on colour was mediated through viability selection and not through fecundity selection. Our results reveal remarkably strong selection on a genetically determined phenotypic trait. PMID:16024349

Natural selection on plant physiological traits in an urban environment

NASA Astrophysics Data System (ADS)

Lambrecht, Susan C.; Mahieu, Stephanie; Cheptou, Pierre-Olivier

2016-11-01

Current rates of urbanization are creating new opportunities for studying urban plant ecology, but our knowledge of urban plant physiology lags behind that of other ecosystems. Moreover, higher temperatures, elevated CO2, and increased inorganic nitrogen deposition along with altered moisture regimes of urban as compared to rural areas creates a compelling analog for studying adaptations of plants to climate change. We grew plants under common conditions in a greenhouse to determine whether populations of Crepis sancta (Asteraceae) differed in phenological, morphological, and physiological traits. We also used a field experiment to test for natural selection on these traits in urban Montpellier, France. Urban plants flowered and senesced later than rural plants, and natural selection favored later phenology in the urban habitat. Natural selection also favored larger plants with more leaves, and increased photosynthesis and leaf nitrogen concentration. Ours is the first study to document selection on plant functional traits in an urban habitat and, as such, advances our understanding of urban plant ecology and possible adaptations to climate change.

Neural representations of faces and body parts in macaque and human cortex: a comparative FMRI study.

PubMed

Pinsk, Mark A; Arcaro, Michael; Weiner, Kevin S; Kalkus, Jan F; Inati, Souheil J; Gross, Charles G; Kastner, Sabine

2009-05-01

Single-cell studies in the macaque have reported selective neural responses evoked by visual presentations of faces and bodies. Consistent with these findings, functional magnetic resonance imaging studies in humans and monkeys indicate that regions in temporal cortex respond preferentially to faces and bodies. However, it is not clear how these areas correspond across the two species. Here, we directly compared category-selective areas in macaques and humans using virtually identical techniques. In the macaque, several face- and body part-selective areas were found located along the superior temporal sulcus (STS) and middle temporal gyrus (MTG). In the human, similar to previous studies, face-selective areas were found in ventral occipital and temporal cortex and an additional face-selective area was found in the anterior temporal cortex. Face-selective areas were also found in lateral temporal cortex, including the previously reported posterior STS area. Body part-selective areas were identified in the human fusiform gyrus and lateral occipitotemporal cortex. In a first experiment, both monkey and human subjects were presented with pictures of faces, body parts, foods, scenes, and man-made objects, to examine the response profiles of each category-selective area to the five stimulus types. In a second experiment, face processing was examined by presenting upright and inverted faces. By comparing the responses and spatial relationships of the areas, we propose potential correspondences across species. Adjacent and overlapping areas in the macaque anterior STS/MTG responded strongly to both faces and body parts, similar to areas in the human fusiform gyrus and posterior STS. Furthermore, face-selective areas on the ventral bank of the STS/MTG discriminated both upright and inverted faces from objects, similar to areas in the human ventral temporal cortex. Overall, our findings demonstrate commonalities and differences in the wide-scale brain organization between the two species and provide an initial step toward establishing functionally homologous category-selective areas.

Neural Representations of Faces and Body Parts in Macaque and Human Cortex: A Comparative fMRI Study

PubMed Central

Pinsk, Mark A.; Arcaro, Michael; Weiner, Kevin S.; Kalkus, Jan F.; Inati, Souheil J.; Gross, Charles G.; Kastner, Sabine

2009-01-01

Single-cell studies in the macaque have reported selective neural responses evoked by visual presentations of faces and bodies. Consistent with these findings, functional magnetic resonance imaging studies in humans and monkeys indicate that regions in temporal cortex respond preferentially to faces and bodies. However, it is not clear how these areas correspond across the two species. Here, we directly compared category-selective areas in macaques and humans using virtually identical techniques. In the macaque, several face- and body part–selective areas were found located along the superior temporal sulcus (STS) and middle temporal gyrus (MTG). In the human, similar to previous studies, face-selective areas were found in ventral occipital and temporal cortex and an additional face-selective area was found in the anterior temporal cortex. Face-selective areas were also found in lateral temporal cortex, including the previously reported posterior STS area. Body part–selective areas were identified in the human fusiform gyrus and lateral occipitotemporal cortex. In a first experiment, both monkey and human subjects were presented with pictures of faces, body parts, foods, scenes, and man-made objects, to examine the response profiles of each category-selective area to the five stimulus types. In a second experiment, face processing was examined by presenting upright and inverted faces. By comparing the responses and spatial relationships of the areas, we propose potential correspondences across species. Adjacent and overlapping areas in the macaque anterior STS/MTG responded strongly to both faces and body parts, similar to areas in the human fusiform gyrus and posterior STS. Furthermore, face-selective areas on the ventral bank of the STS/MTG discriminated both upright and inverted faces from objects, similar to areas in the human ventral temporal cortex. Overall, our findings demonstrate commonalities and differences in the wide-scale brain organization between the two species and provide an initial step toward establishing functionally homologous category-selective areas. PMID:19225169

Background selection as null hypothesis in population genomics: insights and challenges from Drosophila studies

PubMed Central

2017-01-01

The consequences of selection at linked sites are multiple and widespread across the genomes of most species. Here, I first review the main concepts behind models of selection and linkage in recombining genomes, present the difficulty in parametrizing these models simply as a reduction in effective population size (Ne) and discuss the predicted impact of recombination rates on levels of diversity across genomes. Arguments are then put forward in favour of using a model of selection and linkage with neutral and deleterious mutations (i.e. the background selection model, BGS) as a sensible null hypothesis for investigating the presence of other forms of selection, such as balancing or positive. I also describe and compare two studies that have generated high-resolution landscapes of the predicted consequences of selection at linked sites in Drosophila melanogaster. Both studies show that BGS can explain a very large fraction of the observed variation in diversity across the whole genome, thus supporting its use as null model. Finally, I identify and discuss a number of caveats and challenges in studies of genetic hitchhiking that have been often overlooked, with several of them sharing a potential bias towards overestimating the evidence supporting recent selective sweeps to the detriment of a BGS explanation. One potential source of bias is the analysis of non-equilibrium populations: it is precisely because models of selection and linkage predict variation in Ne across chromosomes that demographic dynamics are not expected to be equivalent chromosome- or genome-wide. Other challenges include the use of incomplete genome annotations, the assumption of temporally stable recombination landscapes, the presence of genes under balancing selection and the consequences of ignoring non-crossover (gene conversion) recombination events. This article is part of the themed issue ‘Evolutionary causes and consequences of recombination rate variation in sexual organisms’. PMID:29109230

The effect of morphometric atlas selection on multi-atlas-based automatic brachial plexus segmentation.

PubMed

Van de Velde, Joris; Wouters, Johan; Vercauteren, Tom; De Gersem, Werner; Achten, Eric; De Neve, Wilfried; Van Hoof, Tom

2015-12-23

The present study aimed to measure the effect of a morphometric atlas selection strategy on the accuracy of multi-atlas-based BP autosegmentation using the commercially available software package ADMIRE® and to determine the optimal number of selected atlases to use. Autosegmentation accuracy was measured by comparing all generated automatic BP segmentations with anatomically validated gold standard segmentations that were developed using cadavers. Twelve cadaver computed tomography (CT) atlases were included in the study. One atlas was selected as a patient in ADMIRE®, and multi-atlas-based BP autosegmentation was first performed with a group of morphometrically preselected atlases. In this group, the atlases were selected on the basis of similarity in the shoulder protraction position with the patient. The number of selected atlases used started at two and increased up to eight. Subsequently, a group of randomly chosen, non-selected atlases were taken. In this second group, every possible combination of 2 to 8 random atlases was used for multi-atlas-based BP autosegmentation. For both groups, the average Dice similarity coefficient (DSC), Jaccard index (JI) and Inclusion index (INI) were calculated, measuring the similarity of the generated automatic BP segmentations and the gold standard segmentation. Similarity indices of both groups were compared using an independent sample t-test, and the optimal number of selected atlases was investigated using an equivalence trial. For each number of atlases, average similarity indices of the morphometrically selected atlas group were significantly higher than the random group (p < 0,05). In this study, the highest similarity indices were achieved using multi-atlas autosegmentation with 6 selected atlases (average DSC = 0,598; average JI = 0,434; average INI = 0,733). Morphometric atlas selection on the basis of the protraction position of the patient significantly improves multi-atlas-based BP autosegmentation accuracy. In this study, the optimal number of selected atlases used was six, but for definitive conclusions about the optimal number of atlases and to improve the autosegmentation accuracy for clinical use, more atlases need to be included.

Pilot Study of Agricultural Literacy. Final Report.

ERIC Educational Resources Information Center

Birkenholz, Robert H.; And Others

A study assessed the knowledge and perceptions of U.S. citizens regarding agriculture, food, and natural resources. Data were collected from 2,005 respondents representing the following groups: purposely selected primarily white Indiana high school students and primarily black Michigan high school students, randomly selected rural Missouri adults…

Thriving Latino Males in Selective Predominantly White Institutions

ERIC Educational Resources Information Center

Pérez, David; Sáenz, Victor B.

2017-01-01

Researchers focus disproportionately on the underperformance of Latino males in higher education. In response to this research gap, this study explores how Latino males conceptualized and embodied success at selective, predominantly White institutions. Using qualitative data available from "The National Study on Latino Male Achievement in…

Changes in Landscape Greenness: Anthropogenic or Natural: Proof of Concept, Selected Study Areas

EPA Science Inventory

We selected four National Forest areas that span east to west of USA to conduct the study over the 25-year period from 1989 through 2013: GWJ (Virginia), Chatt-O (Georgia), Kisatchie (Louisiana), Hemlock Restoration (California). The Normalized Difference Vegetation Index (NDV...

Antidepressant use and risk of coronary heart disease: meta-analysis of observational studies

PubMed Central

Oh, Seung-Won; Kim, Joonseok; Myung, Seung-Kwon; Hwang, Seung-Sik; Yoon, Dae-Hyun

2014-01-01

Aims Our goal was to evaluate the association between antidepressant use and the risk of coronary heart disease (CHD) among subjects with no history of coronary heart disease. Methods A search of Medline, EMBASE, PsycINFO and the Cochrane Library was performed in January 2013. Two authors independently reviewed and selected eligible observational studies, based on predetermined selection criteria. Pooled relative risks (RRs) with confidence intervals (CIs) were calculated using random-effects or fixed-effects models. Results Sixteen observational studies (seven case–control studies and nine cohort studies) were included in the final analysis. There was no association between selective serotonin reuptake inhibitor use and the risk of CHD overall [odds ratio (OR), 0.93; 95% CI, 0.65–1.33] or in subgroup meta-analysis of case–control studies (OR, 0.91; 95% CI, 0.60–1.37) and cohort studies (RR, 0.96; 95% CI, 0.59–1.55). The use of tricyclic antidepressant was associated with an increased risk of CHD overall (OR, 1.51; 95% CI, 1.07–2.12), but it was observed only in case–control studies (OR, 1.56; 95% CI, 1.24–1.96) and low-quality studies (OR, 1.49; 95% CI, 1.20–1.85) in the subgroup meta-analyses. Conclusions This meta-analysis of observational studies in subjects with no history of CHD suggests that neither selective serotonin reuptake inhibitor nor tricyclic antidepressant use is associated with an increased risk of CHD. PMID:24646010

Evidence regarding the utility of multiple mini-interview (MMI) for selection to undergraduate health programs: A BEME systematic review: BEME Guide No. 37.

PubMed

Rees, Eliot L; Hawarden, Ashley W; Dent, Gordon; Hays, Richard; Bates, Joanna; Hassell, Andrew B

2016-05-01

In the 11 years since its development at McMaster University Medical School, the multiple mini-interview (MMI) has become a popular selection tool. We aimed to systematically explore, analyze and synthesize the evidence regarding MMIs for selection to undergraduate health programs. The review protocol was peer-reviewed and prospectively registered with the Best Evidence Medical Education (BEME) collaboration. Thirteen databases were searched through 34 terms and their Boolean combinations. Seven key journals were hand-searched since 2004. The reference sections of all included studies were screened. Studies meeting the inclusion criteria were coded independently by two reviewers using a modified BEME coding sheet. Extracted data were synthesized through narrative synthesis. A total of 4338 citations were identified and screened, resulting in 41 papers that met inclusion criteria. Thirty-two studies report data for selection to medicine, six for dentistry, three for veterinary medicine, one for pharmacy, one for nursing, one for rehabilitation, and one for health science. Five studies investigated selection to more than one profession. MMIs used for selection to undergraduate health programs appear to have reasonable feasibility, acceptability, validity, and reliability. Reliability is optimized by including 7-12 stations, each with one examiner. The evidence is stronger for face validity, with more research needed to explore content validity and predictive validity. In published studies, MMIs do not appear biased against applicants on the basis of age, gender, or socio-economic status. However, applicants of certain ethnic and social backgrounds did less well in a very small number of published studies. Performance on MMIs does not correlate strongly with other measures of noncognitive attributes, such as personality inventories and measures of emotional intelligence. MMI does not automatically mean a more reliable selection process but it can do, if carefully designed. Effective MMIs require careful identification of the noncognitive attributes sought by the program and institution. Attention needs to be given to the number of stations, the blueprint and examiner training. More work is required on MMIs as they may disadvantage groups of certain ethnic or social backgrounds. There is a compelling argument for multi-institutional studies to investigate areas such as the relationship of MMI content to curriculum domains, graduate outcomes, and social missions; relationships of applicants' performance on different MMIs; bias in selecting applicants of minority groups; and the long-term outcomes appropriate for studies of predictive validity.

Binding of indomethacin methyl ester to cyclooxygenase-2. A computational study.

PubMed

Sárosi, Menyhárt-Botond

2018-06-05

Inhibitors selective towards the second isoform of prostaglandin synthase (cyclooxygenase, COX-2) are promising nonsteroidal anti-inflammatory drugs and antitumor medications. Methylation of the carboxylate group in the relatively nonselective COX inhibitor indomethacin confers significant COX-2 selectivity. Several other modifications converting indomethacin into a COX-2 selective inhibitor have been reported. Earlier experimental and computational studies on neutral indomethacin derivatives suggest that the methyl ester derivative likely binds to COX-2 with a similar binding mode as that observed for the parent indomethacin. However, docking studies followed by molecular dynamics simulations revealed two possible binding modes in COX-2 for indomethacin methyl ester, which differs from the experimental binding mode found for indomethacin. Both alternative binding modes might explain the observed COX-2 selectivity of indomethacin methyl ester. Graphical abstract Binding of indomethacin methyl ester to cyclooxygenase-2.

The leadership characteristics of the preceptor in selected clinical practice settings in Botswana.

PubMed

Dube, A; Jooste, K

2006-08-01

A non-experimental, explorative, descriptive, quantitative study was undertaken. The purpose was to explore and describe the views of preceptors and preceptees regarding the fulfilment of the role of the preceptor in selected clinical nursing practice settings in the Botswana context. The study included 72 preceptors and 200 nursing students/preceptees who voluntary agreed voluntarily to participate in the study. A questionnaire was used to collect data, which was analyzed by using descriptive and inferential statistics. The findings of this study indicated that the preceptor lacked leadership characteristics in the accompaniment of the preceptee. These constraints included the lack of desirable characteristics such as intellectual, emotional, physical and other traits that are common to all good leaders. Recommendations were stated for improvements in selecting preceptors with certain leadership skills for the clinical practice settings. The limitations of this study were highlighted.

Tilted seat position for non-ambulant individuals with neurological and neuromuscular impairment: a systematic review.

PubMed

Michael, S M; Porter, D; Pountney, T E

2007-12-01

To determine the effects of tilt-in-space seating on outcomes for people with neurological or neuromuscular impairment who cannot walk. Search through electronic databases (MEDLINE, Embase, CINAHL, AMED). Discussions with researchers who are active in field. Selection criteria included interventional studies that investigated the effects of seat tilt on outcome or observational studies that identified outcomes for those who had used tilt-in-space seating in populations with neurological or neuromuscular impairments. Two reviewers independently selected trials for inclusion, assessed quality and extracted data. Nineteen studies were identified which fulfilled the selection criteria. Seventeen of these were essentially before-after studies investigating the immediate effects of tilting the seating. All studies looked at populations with neurological impairment, and most were on children with cerebral palsy (n=8) or adults with spinal cord injury (n=8). REVIEWER'S CONCLUSION: Posterior tilt can reduce pressures at the interface under the pelvis.

Mental health epidemiological research in South America: recent findings

PubMed Central

Silva de Lima, Maurício; Garcia de Oliveira Soares, Bernardo; de Jesus Mari, Jair

2004-01-01

This paper aims to review the recent mental health epidemiological research conducted in South America. The Latin American and the Caribbean (LILACS) database was searched from 1999 to 2003 using a specific strategy for identification of cohort, case-control and cross-sectional population-based studies in South America. The authors screened references and identified relevant studies. Further studies were obtained contacting local experts in epidemiology. 140 references were identified, and 12 studies were selected. Most selected studies explored the prevalence and risk factors for common mental disorders, and several of them used sophisticated methods of sample selection and analysis. There is a need for improving the quality of psychiatric journals in Latin America, and for increasing the distribution and access to research data. Regionally relevant problems such as violence and substance abuse should be considered in designing future investigations in this area. PMID:16633474

Continental-scale footprint of balancing and positive selection in a small rodent (Microtus arvalis).

PubMed

Fischer, Martin C; Foll, Matthieu; Heckel, Gerald; Excoffier, Laurent

2014-01-01

Genetic adaptation to different environmental conditions is expected to lead to large differences between populations at selected loci, thus providing a signature of positive selection. Whereas balancing selection can maintain polymorphisms over long evolutionary periods and even geographic scale, thus leads to low levels of divergence between populations at selected loci. However, little is known about the relative importance of these two selective forces in shaping genomic diversity, partly due to difficulties in recognizing balancing selection in species showing low levels of differentiation. Here we address this problem by studying genomic diversity in the European common vole (Microtus arvalis) presenting high levels of differentiation between populations (average F ST = 0.31). We studied 3,839 Amplified Fragment Length Polymorphism (AFLP) markers genotyped in 444 individuals from 21 populations distributed across the European continent and hence over different environmental conditions. Our statistical approach to detect markers under selection is based on a Bayesian method specifically developed for AFLP markers, which treats AFLPs as a nearly codominant marker system, and therefore has increased power to detect selection. The high number of screened populations allowed us to detect the signature of balancing selection across a large geographic area. We detected 33 markers potentially under balancing selection, hence strong evidence of stabilizing selection in 21 populations across Europe. However, our analyses identified four-times more markers (138) being under positive selection, and geographical patterns suggest that some of these markers are probably associated with alpine regions, which seem to have environmental conditions that favour adaptation. We conclude that despite favourable conditions in this study for the detection of balancing selection, this evolutionary force seems to play a relatively minor role in shaping the genomic diversity of the common vole, which is more influenced by positive selection and neutral processes like drift and demographic history.

Genome-Wide Landscapes of Human Local Adaptation in Asia

PubMed Central

Lu, Dongsheng; Xu, Shuhua

2013-01-01

Genetic studies of human local adaptation have been facilitated greatly by recent advances in high-throughput genotyping and sequencing technologies. However, few studies have investigated local adaptation in Asian populations on a genome-wide scale and with a high geographic resolution. In this study, taking advantage of the dense population coverage in Southeast Asia, which is the part of the world least studied in term of natural selection, we depicted genome-wide landscapes of local adaptations in 63 Asian populations representing the majority of linguistic and ethnic groups in Asia. Using genome-wide data analysis, we discovered many genes showing signs of local adaptation or natural selection. Notable examples, such as FOXQ1, MAST2, and CDH4, were found to play a role in hair follicle development and human cancer, signal transduction, and tumor repression, respectively. These showed strong indications of natural selection in Philippine Negritos, a group of aboriginal hunter-gatherers living in the Philippines. MTTP, which has associations with metabolic syndrome, body mass index, and insulin regulation, showed a strong signature of selection in Southeast Asians, including Indonesians. Functional annotation analysis revealed that genes and genetic variants underlying natural selections were generally enriched in the functional category of alternative splicing. Specifically, many genes showing significant difference with respect to allele frequency between northern and southern Asian populations were found to be associated with human height and growth and various immune pathways. In summary, this study contributes to the overall understanding of human local adaptation in Asia and has identified both known and novel signatures of natural selection in the human genome. PMID:23349834

Interface Pattern Selection Criterion for Cellular Structures in Directional Solidification

NASA Technical Reports Server (NTRS)

Trivedi, R.; Tewari, S. N.; Kurtze, D.

1999-01-01

The aim of this investigation is to establish key scientific concepts that govern the selection of cellular and dendritic patterns during the directional solidification of alloys. We shall first address scientific concepts that are crucial in the selection of interface patterns. Next, the results of ground-based experimental studies in the Al-4.0 wt % Cu system will be described. Both experimental studies and theoretical calculations will be presented to establish the need for microgravity experiments.

Integrative Bayesian variable selection with gene-based informative priors for genome-wide association studies.

PubMed

Zhang, Xiaoshuai; Xue, Fuzhong; Liu, Hong; Zhu, Dianwen; Peng, Bin; Wiemels, Joseph L; Yang, Xiaowei

2014-12-10

Genome-wide Association Studies (GWAS) are typically designed to identify phenotype-associated single nucleotide polymorphisms (SNPs) individually using univariate analysis methods. Though providing valuable insights into genetic risks of common diseases, the genetic variants identified by GWAS generally account for only a small proportion of the total heritability for complex diseases. To solve this "missing heritability" problem, we implemented a strategy called integrative Bayesian Variable Selection (iBVS), which is based on a hierarchical model that incorporates an informative prior by considering the gene interrelationship as a network. It was applied here to both simulated and real data sets. Simulation studies indicated that the iBVS method was advantageous in its performance with highest AUC in both variable selection and outcome prediction, when compared to Stepwise and LASSO based strategies. In an analysis of a leprosy case-control study, iBVS selected 94 SNPs as predictors, while LASSO selected 100 SNPs. The Stepwise regression yielded a more parsimonious model with only 3 SNPs. The prediction results demonstrated that the iBVS method had comparable performance with that of LASSO, but better than Stepwise strategies. The proposed iBVS strategy is a novel and valid method for Genome-wide Association Studies, with the additional advantage in that it produces more interpretable posterior probabilities for each variable unlike LASSO and other penalized regression methods.

An evaluation of selected NASA scientific and technical information products: Results of a pilot study

NASA Technical Reports Server (NTRS)

Pinelli, Thomas E.; Glassman, Myron

1989-01-01

A pilot study was conducted to evaluate selected NASA scientific and technical information (STI) products. The study, which utilized survey research in the form of a self-administered mail questionnaire, had a two-fold purpose -- to gather baseline data regarding the use and perceived usefulness of selected NASA STI products and to develop/validate questions that could be used in a future study concerned with the role of the U.S. government technical report in aeronautics. The sample frame consisted of 25,000 members of the American Institute of Aeronautics and Astronautics in the U.S. with academic, government or industrial affiliation. Simple random sampling was used to select 2000 individuals to participate in the study. Three hundred fifty-three usable questionnaires (17 percent response rate) were received by the established cutoff date. The findings indicate that: (1) NASA STI is used and is generally perceived as being important; (2) the use rate for NASA-authored conference/meeting papers, journal articles, and technical reports is fairly uniform; (3) a considerable number of respondents are unfamiliar with STAR (Scientific and Technical Aerospace Reports), IAA (International Aerospace Abstracts), SCAN (Selected Current Aerospace Notices), and the RECON on-line retrieval system; (4) a considerable number of respondents who are familiar with these media do not use them; and (5) the perceived quality of NASA-authored journal articles and technical reports is very good.

A WISE Selection of MIR AGN in Different Environments

NASA Astrophysics Data System (ADS)

Cheeseboro, Belinda D.; Norman, Dara J.

2015-01-01

This study was undertaken to understand the role of large scale environment in the evolution of MIR-selected AGN. In this study we examine AGN candidates in two types of environments: 7 clusters and 6 blank fields. Two types of clusters were studied in this project: 3 virialized and 4 non-virialized. The redshift of the clusters ranged 0.22≤z≤0.28. We used the mid-infrared WISE All-Sky database to identify AGN, applying various methods to refine our AGN candidate selection. To ascertain if there is an excess or deficit of MIR AGN in galaxy clusters vs. blank fields, we compared the AGN candidate distributions in virialized vs. non-virialized clusters to the blank fields. After close examination and comparison of the results to X-ray selected AGN from the Gilmour et al. (2009) study, we concluded that we do not detect an excess or deficit of MIR AGN in our clusters whether the cluster was virialized or non-virialized. This contrasted the conclusion of the Gilmour et al. (2009) study where there was an excess of X-Ray selected AGN in clusters.We also note an interesting feature in our WISE color-color plots that might be used for further investigation.Cheeseboro was supported by the NOAO/KPNO ResearchExperiences for Undergraduates (REU) Program which is funded by theNational Science Foundation Research Experiences for UndergraduatesProgram (AST-1262829).

Five major controversial issues about fusion level selection in corrective surgery for adolescent idiopathic scoliosis: a narrative review.

PubMed

Lee, Choon Sung; Hwang, Chang Ju; Lee, Dong-Ho; Cho, Jae Hwan

2017-07-01

Shoulder imbalance, coronal decompensation, and adding-on phenomenon following corrective surgery in patients with adolescent idiopathic scoliosis are known to be related to the fusion level selected. Although many studies have assessed the appropriate selection of the proximal and distal fusion level, no definite conclusions have been drawn thus far. We aimed to assess the problems with fusion level selection for corrective surgery in patients with adolescent idiopathic scoliosis, and to enhance understanding about these problems. This study is a narrative review. We conducted a literature search of fusion level selection in corrective surgery for adolescent idiopathic scoliosis. Accordingly, we selected and reviewed five debatable topics related to fusion level selection: (1) selective thoracic fusion; (2) selective thoracolumbar-lumbar (TL-L) fusion; (3) adding-on phenomenon; (4) distal fusion level selection for major TL-L curves; and (5) proximal fusion level selection and shoulder imbalance. Selective fusion can be chosen in specific curve types, although there is a risk of coronal decompensation or adding-on phenomenon. Generally, wider indications for selective fusions are usually associated with more frequent complications. Despite the determination of several indications for selective fusion to avoid such complications, no clear guidelines have been established. Although authors have suggested various criteria to prevent the adding-on phenomenon, no consensus has been reached on the appropriate selection of lower instrumented vertebra. The fusion level selection for major TL-L curves primarily focuses on whether distal fusion can terminate at L3, a topic that remains unclear. Furthermore, because of the presence of several related factors and complications, proximal level selection and shoulder imbalance has been constantly debated and remains controversial from its etiology to its prevention. Although several difficult problems in the diagnosis and treatment of adolescent idiopathic scoliosis have been resolved by understanding its mechanism and via technical advancement, no definite guideline for fusion level selection has been established. A review of five major controversial issues about fusion level selection could provide better understanding of adolescent idiopathic scoliosis. We believe that a thorough validation study of the abovementioned controversial issues can help address them. Copyright © 2017 Elsevier Inc. All rights reserved.

Double level selection in a constitutional dynamic library of coordination driven supramolecular polygons.

PubMed

Rancan, Marzio; Tessarolo, Jacopo; Casarin, Maurizio; Zanonato, Pier Luigi; Quici, Silvio; Armelao, Lidia

2014-07-21

A constitutional dynamic library (CDL) of Cu(II) metallo-supramolecular polygons has been studied as a bench test to examine an interesting selection case based on molecular recognition. Sorting of the CDL polygons is achieved through a proper guest that is hosted into the triangular metallo-macrocycle constituent. Two selection mechanisms are observed, a guest induced path and a guest templated self-assembly (virtual library approach). Remarkably, the triangular host can accommodate several guests with a degree of selectivity ranging from ∼1 to ∼10(4) for all possible guest pairs. A double level selection operates: guests drive the CDL toward the triangular polygon, and, at the same time, this is able to pick a specific guest from a set of competitive molecules, according to a selectivity-affinity correlation. Association constants of the host-guest systems have been determined. Guest competition and exchange studies have been analyzed through variable temperature UV-Vis absorption spectroscopy and single crystal X-ray diffraction studies. Molecular structures and electronic properties of the triangular polygon and of the host-guest systems also have been studied by means of all electrons density functional theory (DFT) and time-dependent density functional theory (TDDFT) calculations including dispersive contributions. DFT outcomes ultimately indicate the dispersive nature of the host-guest interactions, while TDDFT results allow a thorough assignment of the host and host-guests spectral features.

A comparative analysis of experimental selection on the stickleback pelvis.

PubMed

Miller, S E; Barrueto, M; Schluter, D

2017-06-01

Mechanisms of natural selection can be identified using experimental approaches. However, such experiments often yield nonsignificant effects and imprecise estimates of selection due to low power and small sample sizes. Combining results from multiple experimental studies might produce an aggregate estimate of selection that is more revealing than individual studies. For example, bony pelvic armour varies conspicuously among stickleback populations, and predation by vertebrate and insect predators has been hypothesized to be the main driver of this variation. Yet experimental selection studies testing these hypotheses frequently fail to find a significant effect. We experimentally manipulated length of threespine stickleback (Gasterosteus aculeatus) pelvic spines in a mesocosm experiment to test whether prickly sculpin (Cottus asper), an intraguild predator of stickleback, favours longer spines. The probability of survival was greater for stickleback with unclipped pelvic spines, but this effect was noisy and not significant. We used meta-analysis to combine the results of our mesocosm experiment with previously published experimental studies of selection on pelvic armour. We found evidence that fish predation indeed favours increased pelvic armour, with a moderate effect size. The same approach found little evidence that insect predation favours reduced pelvic armour. The causes of reduced pelvic armour in many stickleback populations remain uncertain. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

Successful Decoding of Famous Faces in the Fusiform Face Area

PubMed Central

Axelrod, Vadim; Yovel, Galit

2015-01-01

What are the neural mechanisms of face recognition? It is believed that the network of face-selective areas, which spans the occipital, temporal, and frontal cortices, is important in face recognition. A number of previous studies indeed reported that face identity could be discriminated based on patterns of multivoxel activity in the fusiform face area and the anterior temporal lobe. However, given the difficulty in localizing the face-selective area in the anterior temporal lobe, its role in face recognition is still unknown. Furthermore, previous studies limited their analysis to occipito-temporal regions without testing identity decoding in more anterior face-selective regions, such as the amygdala and prefrontal cortex. In the current high-resolution functional Magnetic Resonance Imaging study, we systematically examined the decoding of the identity of famous faces in the temporo-frontal network of face-selective and adjacent non-face-selective regions. A special focus has been put on the face-area in the anterior temporal lobe, which was reliably localized using an optimized scanning protocol. We found that face-identity could be discriminated above chance level only in the fusiform face area. Our results corroborate the role of the fusiform face area in face recognition. Future studies are needed to further explore the role of the more recently discovered anterior face-selective areas in face recognition. PMID:25714434

The two faces of selective memory retrieval: Earlier decline of the beneficial than the detrimental effect with older age.

PubMed

Aslan, Alp; Schlichting, Andreas; John, Thomas; Bäuml, Karl-Heinz T

2015-12-01

Recent work with young adults has shown that, depending on study context access, selective memory retrieval can both impair and improve recall of other memories (Bäuml & Samenieh, 2010). Here, we investigated the 2 opposing effects of selective retrieval in older age. In Experiment 1, we examined 64 younger (20-35 years) and 64 older participants (above 60 years), and manipulated study context access using list-method directed forgetting. Whereas both age groups showed a detrimental effect of selective retrieval on to-be-remembered items, only younger but not older adults showed a beneficial effect on to-be-forgotten items. In Experiment 2, we examined 112 participants from a relatively wide age range (40-85 years), and manipulated study context access by varying the retention interval between study and test. Overall, a detrimental effect of selective retrieval arose when the retention interval was relatively short, but a beneficial effect when the retention interval was prolonged. Critically, the size of the beneficial but not the detrimental effect of retrieval decreased with age and this age-related decline was mediated by individuals' working memory capacity, as measured by the complex operation span task. Together, the results suggest an age-related dissociation in retrieval dynamics, indicating an earlier decline of the beneficial than the detrimental effect of selective retrieval with older age. (c) 2015 APA, all rights reserved).

Attention in the real world: toward understanding its neural basis

PubMed Central

Peelen, Marius V.; Kastner, Sabine

2016-01-01

The efficient selection of behaviorally relevant objects from cluttered environments supports our everyday goals. Attentional selection has typically been studied in search tasks involving artificial and simplified displays. Although these studies have revealed important basic principles of attention, they do not explain how the brain efficiently selects familiar objects in complex and meaningful real-world scenes. Findings from recent neuroimaging studies indicate that real-world search is mediated by ‘what’ and ‘where’ attentional templates that are implemented in high-level visual cortex. These templates represent target-diagnostic properties and likely target locations, respectively, and are shaped by object familiarity, scene context, and memory. We propose a framework for real-world search that incorporates these recent findings and specifies directions for future study. PMID:24630872

Selecting public relations personnel of hospitals by analytic network process.

PubMed

Liao, Sen-Kuei; Chang, Kuei-Lun

2009-01-01

This study describes the use of analytic network process (ANP) in the Taiwanese hospital public relations personnel selection process. Starting with interviewing 48 practitioners and executives in north Taiwan, we collected selection criteria. Then, we retained the 12 critical criteria that were mentioned above 40 times by theses respondents, including: interpersonal skill, experience, negotiation, language, ability to follow orders, cognitive ability, adaptation to environment, adaptation to company, emotion, loyalty, attitude, and Response. Finally, we discussed with the 20 executives to take these important criteria into three perspectives to structure the hierarchy for hospital public relations personnel selection. After discussing with practitioners and executives, we find that selecting criteria are interrelated. The ANP, which incorporates interdependence relationships, is a new approach for multi-criteria decision-making. Thus, we apply ANP to select the most optimal public relations personnel of hospitals. An empirical study of public relations personnel selection problems in Taiwan hospitals is conducted to illustrate how the selection procedure works.

Category-selective attention modulates unconscious processes in the middle occipital gyrus.

PubMed

Tu, Shen; Qiu, Jiang; Martens, Ulla; Zhang, Qinglin

2013-06-01

Many studies have revealed the top-down modulation (spatial attention, attentional load, etc.) on unconscious processing. However, there is little research about how category-selective attention could modulate the unconscious processing. In the present study, using functional magnetic resonance imaging (fMRI), the results showed that category-selective attention modulated unconscious face/tool processing in the middle occipital gyrus (MOG). Interestingly, MOG effects were of opposed direction for face and tool processes. During unconscious face processing, activation in MOG decreased under the face-selective attention compared with tool-selective attention. This result was in line with the predictive coding theory. During unconscious tool processing, however, activation in MOG increased under the tool-selective attention compared with face-selective attention. The different effects might be ascribed to an interaction between top-down category-selective processes and bottom-up processes in the partial awareness level as proposed by Kouider, De Gardelle, Sackur, and Dupoux (2010). Specifically, we suppose an "excessive activation" hypothesis. Copyright © 2013 Elsevier Inc. All rights reserved.

Using variable rate models to identify genes under selection in sequence pairs: their validity and limitations for EST sequences.

PubMed

Church, Sheri A; Livingstone, Kevin; Lai, Zhao; Kozik, Alexander; Knapp, Steven J; Michelmore, Richard W; Rieseberg, Loren H

2007-02-01

Using likelihood-based variable selection models, we determined if positive selection was acting on 523 EST sequence pairs from two lineages of sunflower and lettuce. Variable rate models are generally not used for comparisons of sequence pairs due to the limited information and the inaccuracy of estimates of specific substitution rates. However, previous studies have shown that the likelihood ratio test (LRT) is reliable for detecting positive selection, even with low numbers of sequences. These analyses identified 56 genes that show a signature of selection, of which 75% were not identified by simpler models that average selection across codons. Subsequent mapping studies in sunflower show four of five of the positively selected genes identified by these methods mapped to domestication QTLs. We discuss the validity and limitations of using variable rate models for comparisons of sequence pairs, as well as the limitations of using ESTs for identification of positively selected genes.

Selection of site specific vibration equation by using analytic hierarchy process in a quarry

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

Kalayci, Ulku, E-mail: ukalayci@istanbul.edu.tr; Ozer, Umit, E-mail: uozer@istanbul.edu.tr

This paper presents a new approach for the selection of the most accurate SSVA (Site Specific Vibration Attenuation) equation for blasting processes in a quarry located near settlements in Istanbul, Turkey. In this context, the SSVA equations obtained from the same study area in the literature were considered in terms of distance between the shot points and buildings and the amount of explosive charge. In this purpose, 11 different SSVA equations obtained from the study area in the past 12 years, forecasting capabilities according to designated new conditions, using 102 vibration records as test data obtained from the study areamore » was investigated. In this study, AHP (Analytic Hierarchy Process) was selected as an analysis method in order to determine the most accurate equation among 11 SSAV equations, and the parameters such as year, distance, charge, and r{sup 2} of the equations were used as criteria for AHP. Finally, the most appropriate equation was selected among the existing ones, and the process of selecting according to different target criteria was presented. Furthermore, it was noted that the forecasting results of the selected equation is more accurate than that formed using the test results. - Highlights: • The optimum Site Specific Vibration Attenuation equation for blasting in a quarry located near settlements was determined. • It is indicated that SSVA equations changing over the years don’t give always accurate estimates at changing conditions. • Selection of the blast induced SSVA equation was made using AHP. • Equation selection method was highlighted based on parameters such as charge, distance, and quarry geometry changes (year).« less

A Comparative Study of the Effectiveness of Two Strategies of Etymological Elaboration and Pictorial Elucidation on Idiom Learning: A Case of Young EFL Iranian Learners

ERIC Educational Resources Information Center

Haghshenas, Mahsa Sadat Mousavi; Hashemian, Mahmood

2016-01-01

This study examined the effect of etymological elaboration, pictorial elucidation, and integration of these 2 strategies on idiom learning by L2 learners. A total number of 80 homogeneous intermediate learners studying English at 3 language institutes in Isfahan, Iran, were selected. The intermediate participants were selected as the result of…

A Case Study of What Experiences Contribute to the Ideas of Energy Held by Primary School Students in Trinidad and Tobago

ERIC Educational Resources Information Center

Maharaj-Sharma, Rawatee; Sharma, Amrit

2014-01-01

This case study explored what experiences contribute to the ideas of energy held by 30 purposively selected primary school students from one primary school in Trinidad and Tobago. The 30 students were selected from across all levels of the primary system. The study used the Interview About Events (IAE) approach to explore students' ideas about…

An Examination of Graduate Theses Related with Guitar in Terms of Methodology and Content: A Case of Turkey

ERIC Educational Resources Information Center

Yöndem, Sadik

2015-01-01

The aim of this study is to examine post-graduate thesis completed on guitar in Turkey. For this purpose, a total of 89 theses were investigated in terms of selected research topics, study participants, and methods for analysis. For the selection of the thesis included in this study three criteria were used; first, theses from 1990 (beginning time…

Integrative Analysis of High-throughput Cancer Studies with Contrasted Penalization

PubMed Central

Shi, Xingjie; Liu, Jin; Huang, Jian; Zhou, Yong; Shia, BenChang; Ma, Shuangge

2015-01-01

In cancer studies with high-throughput genetic and genomic measurements, integrative analysis provides a way to effectively pool and analyze heterogeneous raw data from multiple independent studies and outperforms “classic” meta-analysis and single-dataset analysis. When marker selection is of interest, the genetic basis of multiple datasets can be described using the homogeneity model or the heterogeneity model. In this study, we consider marker selection under the heterogeneity model, which includes the homogeneity model as a special case and can be more flexible. Penalization methods have been developed in the literature for marker selection. This study advances from the published ones by introducing the contrast penalties, which can accommodate the within- and across-dataset structures of covariates/regression coefficients and, by doing so, further improve marker selection performance. Specifically, we develop a penalization method that accommodates the across-dataset structures by smoothing over regression coefficients. An effective iterative algorithm, which calls an inner coordinate descent iteration, is developed. Simulation shows that the proposed method outperforms the benchmark with more accurate marker identification. The analysis of breast cancer and lung cancer prognosis studies with gene expression measurements shows that the proposed method identifies genes different from those using the benchmark and has better prediction performance. PMID:24395534

Role of physicochemical properties in the activation of peroxisome proliferator-activated receptor δ.

PubMed

Maltarollo, Vinícius G; Homem-de-Mello, Paula; Honorio, Káthia M

2011-10-01

Current researches on treatments for metabolic diseases involve a class of biological receptors called peroxisome proliferator-activated receptors (PPARs), which control the metabolism of carbohydrates and lipids. A subclass of these receptors, PPARδ, regulates several metabolic processes, and the substances that activate them are being studied as new drug candidates for the treatment of diabetes mellitus and metabolic syndrome. In this study, several PPARδ agonists with experimental biological activity were selected for a structural and chemical study. Electronic, stereochemical, lipophilic and topological descriptors were calculated for the selected compounds using various theoretical methods, such as density functional theory (DFT). Fisher's weight and principal components analysis (PCA) methods were employed to select the most relevant variables for this study. The partial least squares (PLS) method was used to construct the multivariate statistical model, and the best model obtained had 4 PCs, q ( 2 ) = 0.80 and r ( 2 ) = 0.90, indicating a good internal consistency. The prediction residues calculated for the compounds in the test set had low values, indicating the good predictive capability of our PLS model. The model obtained in this study is reliable and can be used to predict the biological activity of new untested compounds. Docking studies have also confirmed the importance of the molecular descriptors selected for this system.

Developing the Alphabetic Principle to Aid Text-Based Augmentative and Alternative Communication Use by Adults With Low Speech Intelligibility and Intellectual Disabilities

PubMed Central

Schmidt-Naylor, Anna C.; Brady, Nancy C.

2017-01-01

Purpose We explored alphabet supplementation as an augmentative and alternative communication strategy for adults with minimal literacy. Study 1's goal was to teach onset-letter selection with spoken words and assess generalization to untaught words, demonstrating the alphabetic principle. Study 2 incorporated alphabet supplementation within a naming task and then assessed effects on speech intelligibility. Method Three men with intellectual disabilities (ID) and low speech intelligibility participated. Study 1 used a multiple-probe design, across three 20-word sets, to show that our computer-based training improved onset-letter selection. We also probed generalization to untrained words. Study 2 taught onset-letter selection for 30 new words chosen for functionality. Five listeners transcribed speech samples of the 30 words in 2 conditions: speech only and speech with alphabet supplementation. Results Across studies 1 and 2, participants demonstrated onset-letter selection for at least 90 words. Study 1 showed evidence of the alphabetic principle for some but not all word sets. In study 2, participants readily used alphabet supplementation, enabling listeners to understand twice as many words. Conclusions This is the first demonstration of alphabet supplementation in individuals with ID and minimal literacy. The large number of words learned holds promise both for improving communication and providing a foundation for improved literacy. PMID:28474087

Choosing a Surgeon: An Exploratory Study of Factors Influencing Selection of a Gender Affirmation Surgeon.

PubMed

Ettner, Randi; Ettner, Frederic; White, Tonya

2016-01-01

Purpose: Selecting a healthcare provider is often a complicated process. Many factors appear to govern the decision as to how to select the provider in the patient-provider relationship. While the possibility of changing primary care physicians or specialists exists, decisions regarding surgeons are immutable once surgery has been performed. This study is an attempt to assess the importance attached to various factors involved in selecting a surgeon to perform gender affirmation surgery (GAS). It was hypothesized that owing to the intimate nature of the surgery, the expense typically involved, the emotional meaning attached to the surgery, and other variables, decisions regarding choice of surgeon for this procedure would involve factors other than those that inform more typical healthcare provider selection or surgeon selection for other plastic/reconstructive procedures. Methods: Questionnaires were distributed to individuals who had undergone GAS and individuals who had undergone elective plastic surgery to assess decision-making. Results: The results generally confirm previous findings regarding how patients select providers. Conclusion: Choosing a surgeon to perform gender-affirming surgery is a challenging process, but patients are quite rational in their decision-making. Unlike prior studies, we did not find a preference for gender-concordant surgeons, even though the surgery involves the genital area. Providing strategies and resources for surgical selection can improve patient satisfaction.

Artificial selection on ant female caste ratio uncovers a link between female-biased sex ratios and infection by Wolbachia endosymbionts.

PubMed

Pontieri, L; Schmidt, A M; Singh, R; Pedersen, J S; Linksvayer, T A

2017-02-01

Social insect sex and caste ratios are well-studied targets of evolutionary conflicts, but the heritable factors affecting these traits remain unknown. To elucidate these factors, we carried out a short-term artificial selection study on female caste ratio in the ant Monomorium pharaonis. Across three generations of bidirectional selection, we observed no response for caste ratio, but sex ratios rapidly became more female-biased in the two replicate high selection lines and less female-biased in the two replicate low selection lines. We hypothesized that this rapid divergence for sex ratio was caused by changes in the frequency of infection by the heritable bacterial endosymbiont Wolbachia, because the initial breeding stock varied for Wolbachia infection, and Wolbachia is known to cause female-biased sex ratios in other insects. Consistent with this hypothesis, the proportions of Wolbachia-infected colonies in the selection lines changed rapidly, mirroring the sex ratio changes. Moreover, the estimated effect of Wolbachia on sex ratio (~13% female bias) was similar in colonies before and during artificial selection, indicating that this Wolbachia effect is likely independent of the effects of artificial selection on other heritable factors. Our study provides evidence for the first case of endosymbiont sex ratio manipulation in a social insect. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

Perylene Diimide Based Fluorescent Dyes for Selective Sensing of Nitroaromatic Compounds: Selective Sensing in Aqueous Medium Across Wide pH Range.

PubMed

Hariharan, P S; Pitchaimani, J; Madhu, Vedichi; Anthony, Savarimuthu Philip

2016-03-01

Water soluble perylenediimide based fluorophore salt, N,N'-bis(ethelenetrimethyl ammoniumiodide)-perylene-3,4,9,10-tetracarboxylicbisimide (PDI-1), has been used for selective fluorescence sensing of picric acid (PA) and 4-nitroaniline (4-NA) in organic as well as aqueous medium across wide pH range (1.0 to 10.0). PDI-1 showed strong fluorescence in dimethylformamide (DMF) (Φf = 0.26 (DMF) and moderate fluorescence in water. Addition of picric acid (PA) and 4-nitroaniline (4-NA) into PDI-1 in DMF/aqueous solution selectively quenches the fluorescence. The concentration dependent studies showed decrease of fluorescence linearly with increase of PA and 4-NA concentration. The interference studies demonstrate high selectivity for PA and 4-NA. Interestingly, PDI-1 showed selective fluorescence sensing of PA and 4-NA across wide pH range (1.0 to 10.0). Selective fluorescence sensing of PA and 4-NA has also been observed with trifluoroacetate (PDI-2), sulfate (PDI-3) salt of PDI-1 as well as octyl chain substituted PDI (PDI-4) without amine functionality. These studies suggest that PA and 4-NA might be having preferential interaction with PDI aromatic core and quenches the fluorescence. Thus PDI based dyes have been used for selective fluorescent sensing of explosive NACs for the first time to the best our knowledge.

Beyond sex allocation: the role of mating systems in sexual selection in parasitoid wasps

PubMed Central

Boulton, Rebecca A; Collins, Laura A; Shuker, David M

2015-01-01

Despite the diverse array of mating systems and life histories which characterise the parasitic Hymenoptera, sexual selection and sexual conflict in this taxon have been somewhat overlooked. For instance, parasitoid mating systems have typically been studied in terms of how mating structure affects sex allocation. In the past decade, however, some studies have sought to address sexual selection in the parasitoid wasps more explicitly and found that, despite the lack of obvious secondary sexual traits, sexual selection has the potential to shape a range of aspects of parasitoid reproductive behaviour and ecology. Moreover, various characteristics fundamental to the parasitoid way of life may provide innovative new ways to investigate different processes of sexual selection. The overall aim of this review therefore is to re-examine parasitoid biology with sexual selection in mind, for both parasitoid biologists and also researchers interested in sexual selection and the evolution of mating systems more generally. We will consider aspects of particular relevance that have already been well studied including local mating structure, sex allocation and sperm depletion. We go on to review what we already know about sexual selection in the parasitoid wasps and highlight areas which may prove fruitful for further investigation. In particular, sperm depletion and the costs of inbreeding under chromosomal sex determination provide novel opportunities for testing the role of direct and indirect benefits for the evolution of mate choice. PMID:24981603

Case-Control Study Examining the Association between Selective Serotonin Reuptake Inhibitors Use and Hepatocellular Carcinoma.

PubMed

Lai, Shih-Wei; Liao, Kuan-Fu; Lin, Cheng-Li; Lin, Hsien-Feng

2017-01-01

Objectives: The purpose of the study was to assess the relationship between selective serotonin reuptake inhibitors use and hepatocellular carcinoma in Taiwan. Methods: Using the database of the Taiwan National Health Insurance Program, we conducted a case-control study to identify 4901 subjects aged 20 years and more with newly diagnosed hepatocellular carcinoma in 2000-2013 as the cases. We randomly selected 19604 subjects aged 20 years and more without hepatocellular carcinoma as the controls. Both cases and controls were matched with sex and age. Ever use of selective serotonin reuptake inhibitors was defined as a subject who had at least a prescription for selective serotonin reuptake inhibitors before index date. Never use was defined as a subject who never had a prescription for selective serotonin reuptake inhibitors before index date. The odds ratio (OR) and 95% confidence interval (CI) for hepatocellular carcinoma associated with selective serotonin reuptake inhibitors use was estimated by the multivariable logistic regression model. Results: Among subjects with any one of the comorbid conditions associated with hepatocellular carcinoma, the adjusted OR of hepatocellular carcinoma was 0.89 (95% CI 0.75, 1.06) for subjects with ever use of selective serotonin reuptake inhibitors, comparing with never use. Conclusion: The findings indicate that among subjects with any one of the comorbid conditions associated with hepatocellular carcinoma, no significant association can be detected between selective serotonin reuptake inhibitors use and hepatocellular carcinoma.

Perceived Effectiveness among College Students of Selected Statistical Measures in Motivating Exercise Behavior

ERIC Educational Resources Information Center

Merrill, Ray M.; Chatterley, Amanda; Shields, Eric C.

2005-01-01

This study explored the effectiveness of selected statistical measures at motivating or maintaining regular exercise among college students. The study also considered whether ease in understanding these statistical measures was associated with perceived effectiveness at motivating or maintaining regular exercise. Analyses were based on a…

Does Marital Status Influence the Parenting Styles Employed by Parents?

ERIC Educational Resources Information Center

Ashiono, Benard Litali; Mwoma, Teresa B.

2015-01-01

The current study sought to establish whether parents' marital status, influence their use of specific parenting styles in Kisauni District, Kenya. A correlational research design was employed to carry out this study. Stratified sampling technique was used to select preschools while purposive sampling technique was used to select preschool…

Simulation Games: Practical References, Potential Use, Selected Bibliography.

ERIC Educational Resources Information Center

Kidder, Steven J.

Several recently published books on simulation and games are briefly discussed. Selected research studies and demonstration projects are examined to show the potential of simulation and gaming for teaching and training and for the study of social and psychological processes. The bibliography lists 113 publications which should lead the reader to…

An Attentional Application of Socioemotional Selectivity Theory in College Students

ERIC Educational Resources Information Center

Pruzan, Katherine; Isaacowitz, Derek M.

2006-01-01

Socioemotional selectivity theory posits that emotions become increasingly salient as individuals approach endings. Recent findings have linked the theory with biases in information processing in the context of aging. However, these studies all confounded advancing age and the motivational impact of endings. This study represented an attempt to…

Partner Power: A Study of Two Distance Education Consortia

ERIC Educational Resources Information Center

Pidduck, Anne Banks; Carey, Tom

2006-01-01

This research reports findings from a study which explored the process and criteria of partner selection--how and why partners are chosen--for two distance education consortia. The researchers reviewed recent literature on partnerships and partner selection. Two Canada-wide distance education consortia were identified as large-scale case studies…

Narrative Skills in Children with Selective Mutism: An Exploratory Study

ERIC Educational Resources Information Center

McInnes, Alison; Fung, Daniel; Manassis, Katharina; Fiksenbaum, Lisa; Tannock, Rosemary

2004-01-01

Selective mutism (SM) is a rare and complex disorder associated with anxiety symptoms and speech-language deficits; however, the nature of these language deficits has not been studied systematically. A novel cross-disciplinary assessment protocol was used to assess anxiety and nonverbal cognitive, receptive language, and expressive narrative…

The Acceptance of Universalism: The Importance of Selected Aspects of School Structure.

ERIC Educational Resources Information Center

Martin, Robert A.

This report describes a study that investigated empirically the relationships between selected aspects of the organizational structure of elementary schools and the extent to which students endorsed the norm of universalism. Four aspects of structure were studied: degree of departmentalization, school enrollment, student-teacher ratio, and extent…

AN EXPLORATORY STUDY OF PREDICTORS OF PHYSICIAN PERFORMANCE.

ERIC Educational Resources Information Center

JACOBSEN, TONY L.; AND OTHERS

AN ATTEMPT WAS MADE TO DETERMINE THE PREDICTIVE ACCURACY OF THREE MEDICAL SCHOOL SELECTION DEVICES--PREMEDICAL GRADES, THE MEDICAL COLLEGE ADMISSION TEST (MCAT), AND THE BIOGRAPHICAL INVENTORY FOR MEDICINE (BIM). THE BIM REPRESENTS A NEWLY DEVISED SELECTION INSTRUMENT FOR THE MEDICAL SCHOOL. IN THE STUDY, EACH INSTRUMENT WAS VALIDATED AGAINST…

Gender Research in Classrooms: Scientific or Political?

ERIC Educational Resources Information Center

Clarke, John A.; Dart, Barry C.

This paper examines selected Australian studies and studies produced in other countries on gender research of classroom interaction between students and their teachers. The results, deficiencies in methodology, selective reporting of data, and the policies based on the research are highlighted. To substantiate a request for more complex and…

The Chronic and Acute Effects of Exercise Upon Selected Blood Measures.

ERIC Educational Resources Information Center

Roitman, J. L.; Brewer, J. P.

This study investigated the effects of chronic and acute exercise upon selected blood measures and indices. Nine male cross-country runners were studied. Red blood count, hemoglobin, and hematocrit were measured using standard laboratory techniques; mean corpuscular volume (MCV), mean corpuscular hemoglobin, and mean corpuscular hemoglobin…

Studies in Environment--Volume I: Summary Report.

ERIC Educational Resources Information Center

Selden, Maury; Llewellyn, Lynn G.

Twenty-five students who participated as Environmental Protection Agency summer fellows in 1972 were selected from among eight hundred applicants responding to a national recruitment program. The students chosen majored in a wide range of environmentally related studies on university and college campuses across the United States. Selected research…

Differentiating Low Performance of the Gifted Learner: Achieving, Underachieving, and Selective Consuming Students

ERIC Educational Resources Information Center

Figg, Stephanie D.; Rogers, Karen B.; McCormick, John; Low, Renae

2012-01-01

The study aimed to empirically verify findings from qualitative studies that showed selective consumers could be distinguished from underachievers with regard to academic self-perception and thinking style preference. Participants, gifted males from an independent secondary boys' school in Sydney, Australia, were categorized as achieving,…

Inertial Fusion Energy reactor design studies: Prometheus-L, Prometheus-H. Volume 2, Final report

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

Waganer, L.M.; Driemeyer, D.E.; Lee, V.D.

1992-03-01

This report contains a review of design studies for Inertial Confinement reactor. This second of three volumes discussions is some detail the following: Objectives, requirements, and assumptions; rationale for design option selection; key technical issues and R&D requirements; and conceptual design selection and description.

Selected Bibliography for Chicano Studies. Third Edition, 1975.

ERIC Educational Resources Information Center

Gomez-Quinones, Juan; Camarillo, Albert

Reflecting the accelerating growth and diversity of writings on the Chicano since 1970, this selected bibliography gives critical attention to Chicano Studies materials in Spanish and English and emphasizes recent writings in the field. Approximately 900 books and articles, published between 1925 and 1975, are cited. Divided into 25 sections which…

A Comparison of Item Selection Techniques for Testlets

ERIC Educational Resources Information Center

Murphy, Daniel L.; Dodd, Barbara G.; Vaughn, Brandon K.

2010-01-01

This study examined the performance of the maximum Fisher's information, the maximum posterior weighted information, and the minimum expected posterior variance methods for selecting items in a computerized adaptive testing system when the items were grouped in testlets. A simulation study compared the efficiency of ability estimation among the…

An Analysis of Teacher Selection Tools in Pennsylvania

ERIC Educational Resources Information Center

Vitale, Tracy L.

2009-01-01

The purpose of this study was to examine teacher screening and selection tools currently being utilized by public school districts in Pennsylvania and to compare these tools to the research on qualities of effective teachers. The researcher developed four research questions that guided her study. The Pennsylvania Association of School Personnel…

Genetic evidence for natural selection in humans in the contemporary United States.

PubMed

Beauchamp, Jonathan P

2016-07-12

Recent findings from molecular genetics now make it possible to test directly for natural selection by analyzing whether genetic variants associated with various phenotypes have been under selection. I leverage these findings to construct polygenic scores that use individuals' genotypes to predict their body mass index, educational attainment (EA), glucose concentration, height, schizophrenia, total cholesterol, and (in females) age at menarche. I then examine associations between these scores and fitness to test whether natural selection has been occurring. My study sample includes individuals of European ancestry born between 1931 and 1953 who participated in the Health and Retirement Study, a representative study of the US population. My results imply that natural selection has been slowly favoring lower EA in both females and males, and are suggestive that natural selection may have favored a higher age at menarche in females. For EA, my estimates imply a rate of selection of about -1.5 mo of education per generation (which pales in comparison with the increases in EA observed in contemporary times). Although they cannot be projected over more than one generation, my results provide additional evidence that humans are still evolving-albeit slowly, especially compared with the rapid changes that have occurred over the past few generations due to cultural and environmental factors.

Determining Selection across Heterogeneous Landscapes: A Perturbation-Based Method and Its Application to Modeling Evolution in Space.

PubMed

Wickman, Jonas; Diehl, Sebastian; Blasius, Bernd; Klausmeier, Christopher A; Ryabov, Alexey B; Brännström, Åke

2017-04-01

Spatial structure can decisively influence the way evolutionary processes unfold. To date, several methods have been used to study evolution in spatial systems, including population genetics, quantitative genetics, moment-closure approximations, and individual-based models. Here we extend the study of spatial evolutionary dynamics to eco-evolutionary models based on reaction-diffusion equations and adaptive dynamics. Specifically, we derive expressions for the strength of directional and stabilizing/disruptive selection that apply both in continuous space and to metacommunities with symmetrical dispersal between patches. For directional selection on a quantitative trait, this yields a way to integrate local directional selection across space and determine whether the trait value will increase or decrease. The robustness of this prediction is validated against quantitative genetics. For stabilizing/disruptive selection, we show that spatial heterogeneity always contributes to disruptive selection and hence always promotes evolutionary branching. The expression for directional selection is numerically very efficient and hence lends itself to simulation studies of evolutionary community assembly. We illustrate the application and utility of the expressions for this purpose with two examples of the evolution of resource utilization. Finally, we outline the domain of applicability of reaction-diffusion equations as a modeling framework and discuss their limitations.

Theoretical studies on the selective mechanisms of GSK3β and CDK2 by molecular dynamics simulations and free energy calculations.

PubMed

Zhao, Sufang; Zhu, Jingyu; Xu, Lei; Jin, Jian

2017-06-01

Glycogen synthase kinase 3 (GSK3) is a serine/threonine protein kinase which is widely involved in cell signaling and controls a broad number of cellular functions. GSK3 contains α and β isoforms, and GSK3β has received more attention and becomes an attractive drug target for the treatment of several diseases. The binding pocket of cyclin-dependent kinase 2 (CDK2) shares high sequence identity to that of GSK3β, and therefore, the design of highly selective inhibitors toward GSK3β remains a big challenge. In this study, a computational strategy, which combines molecular docking, molecular dynamics simulations, free energy calculations, and umbrella sampling simulations, was employed to explore the binding mechanisms of two selective inhibitors to GSK3β and CDK2. The simulation results highlighted the key residues critical for GSK3β selectivity. It was observed that although GSK3β and CDK2 share the conserved ATP-binding pockets, some different residues have significant contributions to protein selectivity. This study provides valuable information for understanding the GSK3β-selective binding mechanisms and the rational design of selective GSK3β inhibitors. © 2016 John Wiley & Sons A/S.

Genetic evidence for natural selection in humans in the contemporary United States

PubMed Central

Beauchamp, Jonathan P.

2016-01-01

Recent findings from molecular genetics now make it possible to test directly for natural selection by analyzing whether genetic variants associated with various phenotypes have been under selection. I leverage these findings to construct polygenic scores that use individuals’ genotypes to predict their body mass index, educational attainment (EA), glucose concentration, height, schizophrenia, total cholesterol, and (in females) age at menarche. I then examine associations between these scores and fitness to test whether natural selection has been occurring. My study sample includes individuals of European ancestry born between 1931 and 1953 who participated in the Health and Retirement Study, a representative study of the US population. My results imply that natural selection has been slowly favoring lower EA in both females and males, and are suggestive that natural selection may have favored a higher age at menarche in females. For EA, my estimates imply a rate of selection of about −1.5 mo of education per generation (which pales in comparison with the increases in EA observed in contemporary times). Although they cannot be projected over more than one generation, my results provide additional evidence that humans are still evolving—albeit slowly, especially compared with the rapid changes that have occurred over the past few generations due to cultural and environmental factors. PMID:27402742

Selection of multiple cued items is possible during visual short-term memory maintenance.

PubMed

Matsukura, Michi; Vecera, Shaun P

2015-07-01

Recent neuroimaging studies suggest that maintenance of a selected object feature held in visual short-term/working memory (VSTM/VWM) is supported by the same neural mechanisms that encode the sensory information. If VSTM operates by retaining "reasonable copies" of scenes constructed during sensory processing (Serences, Ester, Vogel, & Awh, 2009, p. 207, the sensory recruitment hypothesis), then attention should be able to select multiple items represented in VSTM as long as the number of these attended items does not exceed the typical VSTM capacity. It is well known that attention can select at least two noncontiguous locations at the same time during sensory processing. However, empirical reports from the studies that examined this possibility are inconsistent. In the present study, we demonstrate that (1) attention can indeed select more than a single item during VSTM maintenance when observers are asked to recognize a set of items in the manner that these items were originally attended, and (2) attention can select multiple cued items regardless of whether these items are perceptually organized into a single group (contiguous locations) or not (noncontiguous locations). The results also replicate and extend the recent finding that selective attention that operates during VSTM maintenance is sensitive to the observers' goal and motivation to use the cueing information.

Effects of Mode of Target Task Selection on Learning about Plants in a Mobile Learning Environment: Effortful Manual Selection versus Effortless QR-Code Selection

ERIC Educational Resources Information Center

Gao, Yuan; Liu, Tzu-Chien; Paas, Fred

2016-01-01

This study compared the effects of effortless selection of target plants using quick respond (QR) code technology to effortful manual search and selection of target plants on learning about plants in a mobile device supported learning environment. In addition, it was investigated whether the effectiveness of the 2 selection methods was…

Signatures of selection in tilapia revealed by whole genome resequencing

PubMed Central

Hong Xia, Jun; Bai, Zhiyi; Meng, Zining; Zhang, Yong; Wang, Le; Liu, Feng; Jing, Wu; Yi Wan, Zi; Li, Jiale; Lin, Haoran; Hua Yue, Gen

2015-01-01

Natural selection and selective breeding for genetic improvement have left detectable signatures within the genome of a species. Identification of selection signatures is important in evolutionary biology and for detecting genes that facilitate to accelerate genetic improvement. However, selection signatures, including artificial selection and natural selection, have only been identified at the whole genome level in several genetically improved fish species. Tilapia is one of the most important genetically improved fish species in the world. Using next-generation sequencing, we sequenced the genomes of 47 tilapia individuals. We identified a total of 1.43 million high-quality SNPs and found that the LD block sizes ranged from 10–100 kb in tilapia. We detected over a hundred putative selective sweep regions in each line of tilapia. Most selection signatures were located in non-coding regions of the tilapia genome. The Wnt signaling, gonadotropin-releasing hormone receptor and integrin signaling pathways were under positive selection in all improved tilapia lines. Our study provides a genome-wide map of genetic variation and selection footprints in tilapia, which could be important for genetic studies and accelerating genetic improvement of tilapia. PMID:26373374

Exploring the views and experiences of HIV positive patients treated for cancer: a systematic review of the literature.

PubMed

Hainsworth, Emma G; Shahmanesh, Maryam; Stevenson, Fiona

2018-05-01

A systematic review of the literature was conducted to find out what is known about patients' experiences of a dual diagnosis of HIV and cancer. We systematically searched the following databases; MEDLINE (Ovid Version); CINAHL Plus; PsycINFO and EMBASE from inception to June 2016 for studies that included patients with a dual diagnosis of cancer and HIV and focused on patient experiences. Studies with a focus on one illness rather than a dual diagnosis, those that focused on treatment strategies and medical management, epidemiology and pathology studies and comparison studies were all excluded. The full text of the included studies were reviewed. Information on location, sample size, study design and a narrative summary of findings were extracted using a standardised format. Studies were combined thematically. 1777 records were screened by title and abstract using the selection criteria described in the methods. Eight records were reviewed in depth in full text and seven selected as eligible. The selected studies suggest that a dual diagnosis of HIV and cancer has a powerful impact on individuals' behaviour. The experience of stigma was a consistent factor in all patient accounts and the strategy of selective disclosure to access support reveals how patient agency can interplay with stigma. This is an area largely unexplored in the published literature; further research into patients' experiences of a dual diagnosis of HIV and cancer will provide relevant knowledge in order to tailor and improve services.

Effectiveness of hip muscle strengthening in patellofemoral pain syndrome patients: a systematic review.

PubMed

Santos, Thiago R T; Oliveira, Bárbara A; Ocarino, Juliana M; Holt, Kenneth G; Fonseca, Sérgio T

2015-01-01

Patellofemoral pain syndrome (PFPS) is characterized by anterior knee pain, which may limit the performance of functional activities. The influence of hip joint motion on the development of this syndrome has already been documented in the literature. In this regard, studies have investigated the effectiveness of hip muscle strengthening in patients with PFPS. The aims of this systematic review were (1) to summarize the literature related to the effects of hip muscle strengthening on pain intensity, muscle strength, and function in individuals with PFPS and (2) to evaluate the methodological quality of the selected studies. A search for randomized controlled clinical trials was conducted using the following databases: Google Scholar, MEDLINE, PEDro, LILACS, and SciELO. The selected studies had to distinguish the effects of hip muscle strengthening in a group of patients with PFPS, as compared to non-intervention or other kinds of intervention, and had to investigate the following outcomes: pain, muscle strength, and function. The methodological quality of the selected studies was analyzed by means of the PEDro scale. Seven studies were selected. These studies demonstrated that hip muscle strengthening was effective in reducing pain. However, the studies disagreed regarding the treatments' ability to improve muscle strength. Improvement in functional capabilities after hip muscle strengthening was found in five studies. Hip muscle strengthening is effective in reducing the intensity of pain and improving functional capabilities in patients with PFPS, despite the lack of evidence for its ability to increase muscle strength.

[Selection of risk and diagnosis in diabetic polyneuropathy. Validation of method of new systems].

PubMed

Jurado, Jerónimo; Caula, Jacinto; Pou i Torelló, Josep Maria

2006-06-30

In a previous study we developed a specific algorithm, the polyneuropathy selection method (PSM) with 4 parameters (age, HDL-C, HbA1c, and retinopathy), to select patients at risk of diabetic polyneuropathy (DPN). We also developed a simplified method for DPN diagnosis: outpatient polyneuropathy diagnosis (OPD), with 4 variables (symptoms and 3 objective tests). To confirm the validity of conventional tests for DPN diagnosis; to validate the discriminatory power of the PSM and the diagnostic value of OPD by evaluating their relationship to electrodiagnosis studies and objective clinical neurological assessment; and to evaluate the correlation of DPN and pro-inflammatory status. Cross-sectional, crossed association for PSM validation. Paired samples for OPD validation. Primary care in 3 counties. Random sample of 75 subjects from the type-2 diabetes census for PSM evaluation. Thirty DPN patients and 30 non-DPN patients (from 2 DM2 sub-groups in our earlier study) for OPD evaluation. The gold standard for DPN diagnosis will be studied by means of a clinical neurological study (symptoms, physical examination, and sensitivity tests) and electrodiagnosis studies (sensitivity and motor EMG). Risks of neuropathy, macroangiopathy and pro-inflammatory status (PCR, TNF soluble fraction and total TGF-beta1) will be studied in every subject. Electrodiagnosis studies should confirm the validity of conventional tests for DPN diagnosis. PSM and OPD will be valid methods for selecting patients at risk and diagnosing DPN. There will be a significant relationship between DPN and pro-inflammatory tests.

Self-selection and bias in a large prospective pregnancy cohort in Norway.

PubMed

Nilsen, Roy M; Vollset, Stein Emil; Gjessing, Håkon K; Skjaerven, Rolv; Melve, Kari K; Schreuder, Patricia; Alsaker, Elin R; Haug, Kjell; Daltveit, Anne Kjersti; Magnus, Per

2009-11-01

Self-selection in epidemiological studies may introduce selection bias and influence the validity of study results. To evaluate potential bias due to self-selection in a large prospective pregnancy cohort in Norway, the authors studied differences in prevalence estimates and association measures between study participants and all women giving birth in Norway. Women who agreed to participate in the Norwegian Mother and Child Cohort Study (43.5% of invited; n = 73 579) were compared with all women giving birth in Norway (n = 398 849) using data from the population-based Medical Birth Registry of Norway in 2000-2006. Bias in the prevalence of 23 exposure and outcome variables was measured as the ratio of relative frequencies, whereas bias in exposure-outcome associations of eight relationships was measured as the ratio of odds ratios. Statistically significant relative differences in prevalence estimates between the cohort participants and the total population were found for all variables, except for maternal epilepsy, chronic hypertension and pre-eclampsia. There was a strong under-representation of the youngest women (<25 years), those living alone, mothers with more than two previous births and with previous stillbirths (relative deviation 30-45%). In addition, smokers, women with stillbirths and neonatal death were markedly under-represented in the cohort (relative deviation 22-43%), while multivitamin and folic acid supplement users were over-represented (relative deviation 31-43%). Despite this, no statistically relative differences in association measures were found between participants and the total population regarding the eight exposure-outcome associations. Using data from the Medical Birth Registry of Norway, this study suggests that prevalence estimates of exposures and outcomes, but not estimates of exposure-outcome associations are biased due to self-selection in the Norwegian Mother and Child Cohort Study.

Stimulus-response compatibility and psychological refractory period effects: implications for response selection

NASA Technical Reports Server (NTRS)

Lien, Mei-Ching; Proctor, Robert W.

2002-01-01

The purpose of this paper was to provide insight into the nature of response selection by reviewing the literature on stimulus-response compatibility (SRC) effects and the psychological refractory period (PRP) effect individually and jointly. The empirical findings and theoretical explanations of SRC effects that have been studied within a single-task context suggest that there are two response-selection routes-automatic activation and intentional translation. In contrast, all major PRP models reviewed in this paper have treated response selection as a single processing stage. In particular, the response-selection bottleneck (RSB) model assumes that the processing of Task 1 and Task 2 comprises two separate streams and that the PRP effect is due to a bottleneck located at response selection. Yet, considerable evidence from studies of SRC in the PRP paradigm shows that the processing of the two tasks is more interactive than is suggested by the RSB model and by most other models of the PRP effect. The major implication drawn from the studies of SRC effects in the PRP context is that response activation is a distinct process from final response selection. Response activation is based on both long-term and short-term task-defined S-R associations and occurs automatically and in parallel for the two tasks. The final response selection is an intentional act required even for highly compatible and practiced tasks and is restricted to processing one task at a time. Investigations of SRC effects and response-selection variables in dual-task contexts should be conducted more systematically because they provide significant insight into the nature of response-selection mechanisms.

Selective mutism.

PubMed

Hua, Alexandra; Major, Nili

2016-02-01

Selective mutism is a disorder in which an individual fails to speak in certain social situations though speaks normally in other settings. Most commonly, this disorder initially manifests when children fail to speak in school. Selective mutism results in significant social and academic impairment in those affected by it. This review will summarize the current understanding of selective mutism with regard to diagnosis, epidemiology, cause, prognosis, and treatment. Studies over the past 20 years have consistently demonstrated a strong relationship between selective mutism and anxiety, most notably social phobia. These findings have led to the recent reclassification of selective mutism as an anxiety disorder in the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition. In addition to anxiety, several other factors have been implicated in the development of selective mutism, including communication delays and immigration/bilingualism, adding to the complexity of the disorder. In the past few years, several randomized studies have supported the efficacy of psychosocial interventions based on a graduated exposure to situations requiring verbal communication. Less data are available regarding the use of pharmacologic treatment, though there are some studies that suggest a potential benefit. Selective mutism is a disorder that typically emerges in early childhood and is currently conceptualized as an anxiety disorder. The development of selective mutism appears to result from the interplay of a variety of genetic, temperamental, environmental, and developmental factors. Although little has been published about selective mutism in the general pediatric literature, pediatric clinicians are in a position to play an important role in the early diagnosis and treatment of this debilitating condition.

Comparative analysis of transverse intrafascicular multichannel, longitudinal intrafascicular and multipolar cuff electrodes for the selective stimulation of nerve fascicles

NASA Astrophysics Data System (ADS)

Badia, Jordi; Boretius, Tim; Andreu, David; Azevedo-Coste, Christine; Stieglitz, Thomas; Navarro, Xavier

2011-06-01

The selection of a suitable nerve electrode for neuroprosthetic applications implies a trade-off between invasiveness and selectivity, wherein the ultimate goal is achieving the highest selectivity for a high number of nerve fascicles by the least invasiveness and potential damage to the nerve. The transverse intrafascicular multichannel electrode (TIME) is intended to be transversally inserted into the peripheral nerve and to be useful to selectively activate subsets of axons in different fascicles within the same nerve. We present a comparative study of TIME, LIFE and multipolar cuff electrodes for the selective stimulation of small nerves. The electrodes were implanted on the rat sciatic nerve, and the activation of gastrocnemius, plantar and tibialis anterior muscles was recorded by EMG signals. Thus, the study allowed us to ascertain the selectivity of stimulation at the interfascicular and also at the intrafascicular level. The results of this study indicate that (1) intrafascicular electrodes (LIFE and TIME) provide excitation circumscribed to the implanted fascicle, whereas extraneural electrodes (cuffs) predominantly excite nerve fascicles located superficially; (2) the minimum threshold for muscle activation with TIME and LIFE was significantly lower than with cuff electrodes; (3) TIME allowed us to selectively activate the three tested muscles when stimulating through different active sites of one device, both at inter- and intrafascicular levels, whereas selective activation using multipolar cuff (with a longitudinal tripolar stimulation configuration) was only possible for two muscles, at the interfascicular level, and LIFE did not activate selectively more than one muscle in the implanted nerve fascicle.

Natural and sexual selection in a monogamous historical human population.

PubMed

Courtiol, Alexandre; Pettay, Jenni E; Jokela, Markus; Rotkirch, Anna; Lummaa, Virpi

2012-05-22

Whether and how human populations exposed to the agricultural revolution are still affected by Darwinian selection remains controversial among social scientists, biologists, and the general public. Although methods of studying selection in natural populations are well established, our understanding of selection in humans has been limited by the availability of suitable datasets. Here, we present a study comparing the maximum strengths of natural and sexual selection in humans that includes the effects of sex and wealth on different episodes of selection. Our dataset was compiled from church records of preindustrial Finnish populations characterized by socially imposed monogamy, and it contains a complete distribution of survival, mating, and reproductive success for 5,923 individuals born 1760-1849. Individual differences in early survival and fertility (natural selection) were responsible for most variation in fitness, even among wealthier individuals. Variance in mating success explained most of the higher variance in reproductive success in males compared with females, but mating success also influenced reproductive success in females, allowing for sexual selection to operate in both sexes. The detected opportunity for selection is in line with measurements for other species but higher than most previous reports for human samples. This disparity results from biological, demographic, economic, and social differences across populations as well as from failures by most previous studies to account for variation in fitness introduced by nonreproductive individuals. Our results emphasize that the demographic, cultural, and technological changes of the last 10,000 y did not preclude the potential for natural and sexual selection in our species.

Natural and sexual selection in a monogamous historical human population

PubMed Central

Courtiol, Alexandre; Pettay, Jenni E.; Jokela, Markus; Rotkirch, Anna; Lummaa, Virpi

2012-01-01

Whether and how human populations exposed to the agricultural revolution are still affected by Darwinian selection remains controversial among social scientists, biologists, and the general public. Although methods of studying selection in natural populations are well established, our understanding of selection in humans has been limited by the availability of suitable datasets. Here, we present a study comparing the maximum strengths of natural and sexual selection in humans that includes the effects of sex and wealth on different episodes of selection. Our dataset was compiled from church records of preindustrial Finnish populations characterized by socially imposed monogamy, and it contains a complete distribution of survival, mating, and reproductive success for 5,923 individuals born 1760–1849. Individual differences in early survival and fertility (natural selection) were responsible for most variation in fitness, even among wealthier individuals. Variance in mating success explained most of the higher variance in reproductive success in males compared with females, but mating success also influenced reproductive success in females, allowing for sexual selection to operate in both sexes. The detected opportunity for selection is in line with measurements for other species but higher than most previous reports for human samples. This disparity results from biological, demographic, economic, and social differences across populations as well as from failures by most previous studies to account for variation in fitness introduced by nonreproductive individuals. Our results emphasize that the demographic, cultural, and technological changes of the last 10,000 y did not preclude the potential for natural and sexual selection in our species. PMID:22547810

[Can Psychometric Tests Predict Success in the Selection Interview for Medical School? A Cross-Sectional Study at One German Medical School].

PubMed

Kötter, T; Obst, K U; Brüheim, L; Eisemann, N; Voltmer, E; Katalinic, A

2017-07-01

Background The final exam grade is the main selection criterion for medical school application in Germany. For academic success, it seems to be a reliable predictor. Its use as the only selection criterion is, however, criticised. At some universities, personal interviews are part of the selection process. However, these are very time consuming and are of doubtful validity. The (additional) use of appropriate psychometric instruments could reduce the cost and increase the validity. This study investigates the extent to which psychometric instruments can predict the outcome of a personal selection interview. Methods This is a cross-sectional study on the correlation of the results of psychometric instruments with those of the personal selection interview as part of the application process. As the outcome, the score of the selection interview was used. The NEO - Five Factor Inventory, the Hospital Anxiety and Depression Scale (HADS) and the questionnaire to identify work-related behaviour and experience patterns (AVEM) were used as psychometric interviews. Results There was a statistically significant correlation with the results of the personal selection interview for the sum score of the depression scale from the HADS and the sum score for the dimension of life satisfaction of the AVEM. In addition, those participants who did not previously complete an application training achieved a better result in the selection interview. Conclusion The instruments used measure different aspects than the interviews and cannot replace them. It remains to be seen whether the selected parameters are able to predict academic success. © Georg Thieme Verlag KG Stuttgart · New York.

Beef Cattle: Selection and Evaluation.

ERIC Educational Resources Information Center

Clemson Univ., SC. Vocational Education Media Center.

Designed for secondary vocational agriculture students, this text provides an overview of selecting and evaluating beef cattle in Future Farmers of America livestock judging events. The first of four major sections addresses topics such as the ideal beef animal, selecting steers, selecting breeding animals, studying the animal systematically, and…

Effectiveness comparison of cardio-selective to non-selective β-blockers and their association with mortality and morbidity in end-stage renal disease: a retrospective cohort study.

PubMed

Shireman, Theresa I; Mahnken, Jonathan D; Phadnis, Milind A; Ellerbeck, Edward F

2016-03-25

Within-class comparative effectiveness studies of β-blockers have not been performed in the chronic dialysis setting. With widespread cardiac disease in these patients and potential mechanistic differences within the class, we examined whether mortality and morbidity outcomes varied between cardio-selective and non-selective β-blockers. Retrospective observational study of within class β-blocker exposure among a national cohort of new chronic dialysis patients (N = 52,922) with hypertension and dual eligibility (Medicare-Medicaid). New β-blocker users were classified according to their exclusive use of one of the subclasses. Outcomes were all-cause mortality (ACM) and cardiovascular morbidity and mortality (CVMM). The associations of cardio-selective and non-selective agents on outcomes were adjusted for baseline characteristics using Cox proportional hazards. There were 4938 new β-blocker users included in the ACM model and 4537 in the CVMM model: 77 % on cardio-selective β-blockers. Exposure to cardio-selective and non-selective agents during the follow-up period was comparable, as measured by proportion of days covered (0.56 vs. 0.53 in the ACM model; 0.56 vs 0.54 in the CVMM model). Use of cardio-selective β-blockers was associated with lower risk for mortality (AHR = 0.84; 99 % CI = 0.72-0.97, p = 0.0026) and lower risk for CVMM events (AHR = 0.86; 99 % CI = 0.75-0.99, p = 0.0042). Among new β-blockers users on chronic dialysis, cardio-selective agents were associated with a statistically significant 16 % reduction in mortality and 14 % in cardiovascular morbidity and mortality relative to non-selective β-blocker users. A randomized clinical trial would be appropriate to more definitively answer whether cardio-selective β-blockers are superior to non-selective β-blockers in the setting of chronic dialysis.

Prioritizing comparative effectiveness research for cancer diagnostics using a regional stakeholder approach.

PubMed

Klein, Gregory; Gold, Laura S; Sullivan, Sean D; Buist, Diana S M; Ramsey, Scott; Kreizenbeck, Karma; Snell, Kyle; Loggers, Elizabeth Trice; Gifford, Joseph; Watkins, John B; Kessler, Larry

2012-05-01

This paper describes our process to engage regional stakeholders for prioritizing comparative effectiveness research (CER) in cancer diagnostics. We also describe a novel methodology for incorporating stakeholder data and input to inform the objectives of selected CER studies. As an integrated component to establishing the infrastructure for community-based CER on diagnostic technologies, we have assembled a regional stakeholder group composed of local payers, clinicians and state healthcare representatives to not only identify and prioritize CER topics most important to the western Washington State region, but also to inform the study design of selected research areas. A landscape analysis process combining literature searches, expert consultations and stakeholder discussions was used to identify possible CER topics in cancer diagnostics. Stakeholders prioritized the top topics using a modified Delphi/group-nominal method and a standardized evaluation criteria framework to determine a final selected CER study area. Implementation of the selected study was immediate due to a unique American Recovery and Reinvestment Act funding structure involving the same researchers and stakeholders in both the prioritization and execution phases of the project. Stakeholder engagement was enhanced after study selection via a rapid analysis of a subset of payers' internal claims, coordinated by the research team, to obtain summary data of imaging patterns of use. Results of this preliminary analysis, which we termed an 'internal analysis,' were used to determine with the stakeholders the most important and feasible study objectives. Stakeholders identified PET and MRI in cancers including breast, lung, lymphoma and colorectal as top priorities. In an internal analysis of breast cancer imaging, summary data from three payers demonstrated utilization rates of advanced imaging increased between 2002 and 2009 in the study population, with a great deal of variability in use between different health plans. Assessing whether breast MRI affects treatment decisions was the top breast cancer study objective selected by the stakeholders. There were other high-priority research areas including whether MRI use improved survival that were not deemed feasible with the length of follow-up time following MRI adoption. Continuous stakeholder engagement greatly enhanced their enthusiasm for the project. We believe CER implementation will be more successful when undertaken by regional stakeholders.

A grand canonical Monte Carlo study of SO2 capture using functionalized bilayer graphene nanoribbons.

PubMed

Maurya, Manish; Singh, Jayant K

2017-01-28

Grand canonical Monte Carlo (GCMC) simulation is used to study the adsorption of pure SO 2 using a functionalized bilayer graphene nanoribbon (GNR) at 303 K. The functional groups considered in this work are OH, COOH, NH 2 , NO 2 , and CH 3 . The mole percent of functionalization considered in this work is in the range of 3.125%-6.25%. GCMC simulation is further used to study the selective adsorption of SO 2 from binary and ternary mixtures of SO 2 , CO 2 , and N 2 , of variable composition using the functionalized bilayer graphene nanoribbon at 303 K. This study shows that the adsorption and selectivity of SO 2 increase after the functionalization of the nanoribbon compared to the hydrogen terminated nanoribbon. The order of adsorption capacity and selectivity of the functionalized nanoribbon is found to follow the order COOH > NO 2 > NH 2 > CH 3 > OH > H. The selectivity of SO 2 is found to be maximum at a pressure less than 0.2 bar. Furthermore, SO 2 selectivity and adsorption capacity decrease with increase in the molar ratio of SO 2 /N 2 mixture from 1:1 to 1:9. In the case of ternary mixture of SO 2 , CO 2 , N 2 , having compositions of 0.05, 0.15, 0.8, the selectivity of SO 2 over N 2 is higher than that of CO 2 over N 2 . The maximum selectivity of SO 2 over CO 2 is observed for the COOH functionalized GNR followed by NO 2 and other functionalized GNRs.

Clinical trial allocation in multinational pharmaceutical companies - a qualitative study on influential factors.

PubMed

Dombernowsky, Tilde; Haedersdal, Merete; Lassen, Ulrik; Thomsen, Simon F

2017-06-01

Clinical trial allocation in multinational pharmaceutical companies includes country selection and site selection. With emphasis on site selection, the overall aim of this study was to examine which factors pharmaceutical companies value most when allocating clinical trials. The specific aims were (1) to identify key decision makers during country and site selection, respectively, (2) to evaluate by which parameters subsidiaries are primarily assessed by headquarters with regard to conducting clinical trials, and (3) to evaluate which site-related qualities companies value most when selecting trial sites. Eleven semistructured interviews were conducted among employees engaged in trial allocation at 11 pharmaceutical companies. The interviews were analyzed by deductive content analysis, which included coding of data to a categorization matrix containing categories of site-related qualities. The results suggest that headquarters and regional departments are key decision makers during country selection, whereas subsidiaries decide on site selection. Study participants argued that headquarters primarily value timely patient recruitment and quality of data when assessing subsidiaries. The site-related qualities most commonly emphasized during interviews were study population availability, timely patient recruitment, resources at the site, and site personnel's interest and commitment. Costs of running the trials were described as less important. Site personnel experience in conducting trials was described as valuable but not imperative. In conclusion, multinational pharmaceutical companies consider recruitment-related factors as crucial when allocating clinical trials. Quality of data and site personnel's interest and commitment are also essential, whereas costs seem less important. While valued, site personnel experience in conducting clinical trials is not imperative.

Bim-mediated apoptosis is not necessary for thymic negative selection to ubiquitous self-antigens.

PubMed

Hu, Qian; Sader, Alyssa; Parkman, Julia C; Baldwin, Troy A

2009-12-15

T cell education in the thymus is critical for establishing a functional, yet self-tolerant, T cell repertoire. Negative selection is a key process in enforcing self-tolerance. There are many questions that surround the mechanism of negative selection, but it is currently held that apoptosis initiated by Bim and/or Nur77 is critical for negative selection. Recent studies, however, have questioned the necessity of Bim in maintaining both central and peripheral T cell tolerance. To reconcile these apparently contradictory findings, we examined the role of Bim in negative selection in the well-characterized, physiological HY(cd4) mouse model. We found that while Bim expression was required for CD4(+)CD8(+) double-positive thymocyte apoptosis, it was not required for negative selection. Furthermore, Bim deficiency did not alter the frequency or affinity of male reactive cells that escape negative selection in an oligoclonal repertoire. Collectively, these studies indicate that negative selection occurs efficiently in the absence of apoptosis and suggest that the current paradigm of negative selection requiring apoptosis be revisited.

Roosting habitat use and selection by northern spotted owls during natal dispersal

USGS Publications Warehouse

Sovern, Stan G.; Forsman, Eric D.; Dugger, Catherine M.; Taylor, Margaret

2015-01-01

We studied habitat selection by northern spotted owls (Strix occidentalis caurina) during natal dispersal in Washington State, USA, at both the roost site and landscape scales. We used logistic regression to obtain parameters for an exponential resource selection function based on vegetation attributes in roost and random plots in 76 forest stands that were used for roosting. We used a similar analysis to evaluate selection of landscape habitat attributes based on 301 radio-telemetry relocations and random points within our study area. We found no evidence of within-stand selection for any of the variables examined, but 78% of roosts were in stands with at least some large (>50 cm dbh) trees. At the landscape scale, owls selected for stands with high canopy cover (>70%). Dispersing owls selected vegetation types that were more similar to habitat selected by adult owls than habitat that would result from following guidelines previously proposed to maintain dispersal habitat. Our analysis indicates that juvenile owls select stands for roosting that have greater canopy cover than is recommended in current agency guidelines.

Active season microhabitat and vegetation selection by giant gartersnakes associated with a restored marsh in California

USGS Publications Warehouse

Halstead, Brian J.; Valcarcel, Patricia; Wylie, Glenn D.; Coates, Peter S.; Casazza, Michael L.; Rosenberg, Daniel K.

2016-01-01

Studies of habitat selection can reveal important patterns to guide habitat restoration and management for species of conservation concern. Giant gartersnakes Thamnophis gigas are endemic to the Central Valley of California, where >90% of their historical wetland habitat has been converted to agricultural and other uses. Information about the selection of habitats by individual giant gartersnakes would guide habitat restoration by indicating which habitat features and vegetation types are likely to be selected by these rare snakes. We examined activity patterns and selection of microhabitats and vegetation types by adult female giant gartersnakes with radiotelemetry at a site composed of rice agriculture and restored wetlands using a paired case-control study design. Adult female giant gartersnakes were 14.7 (95% credible interval [CRI] = 9.4–23.7) times more likely to be active (foraging, mating, or moving) when located in aquatic habitats than when located in terrestrial habitats. Microhabitats associated with cover—particularly emergent vegetation, terrestrial vegetation, and litter—were positively selected by giant gartersnakes. Individual giant gartersnakes varied greatly in their selection of rice and rock habitats, but varied little in their selection of open water. Tules Schoenoplectus acutus were the most strongly selected vegetation type, and duckweed Lemna spp., water-primrose Ludwigia spp., forbs, and grasses also were positively selected at the levels of availability observed at our study site. Management practices that promote the interface of water with emergent aquatic and herbaceous terrestrial vegetation will likely benefit giant gartersnakes. Given their strong selection of tules, restoration of native tule marshes will likely provide the greatest benefit to these threatened aquatic snakes.

Successful selection of rainbow trout (Oncorhynchus mykiss) on their ability to grow with a diet completely devoid of fishmeal and fish oil, and correlated changes in nutritional traits.

PubMed

Callet, Thérèse; Médale, Françoise; Larroquet, Laurence; Surget, Anne; Aguirre, Pierre; Kerneis, Thierry; Labbé, Laurent; Quillet, Edwige; Geurden, Inge; Skiba-Cassy, Sandrine; Dupont-Nivet, Mathilde

2017-01-01

In the context of limited marine resources, the exponential growth of aquaculture requires the substitution of fish oil and fishmeal, the traditional components of fish feeds by terrestrial plant ingredients. High levels of such substitution are known to negatively impact fish performance such as growth and survival in rainbow trout (Oncorhynchus mykiss) as in other salmonids. In this respect, genetic selection is a key enabler for improving those performances and hence for the further sustainable development of aquaculture. We selected a rainbow trout line over three generations for its ability to survive and grow on a 100% plant-based diet devoid of both fish oil and fishmeal (V diet) from the very first meal. In the present study, we compared the control line and the selected line after 3 generations of selection, both fed either the V diet or a marine resources-based diet (M diet). The objective of the study was to assess the efficiency of selection and the consequences on various correlated nutritional traits: feed intake, feed efficiency, digestibility, composition of whole fish, nutrient retention and fatty acid (FA) profile. We demonstrated that the genetic variability present in our rainbow trout population can be selected to improve survival and growth. The major result of the study is that after only three generations of selection, selected fish fed the V diet grew at the same rate as the control line fed the M diet, whilst the relative reduction of body weight was 36.8% before the selection. This enhanced performance on the V diet seems to be mostly linked to a higher feed intake for the selected fish.

The predictive validity of selection for entry into postgraduate training in general practice: evidence from three longitudinal studies

PubMed Central

Patterson, Fiona; Lievens, Filip; Kerrin, Máire; Munro, Neil; Irish, Bill

2013-01-01

Background The selection methodology for UK general practice is designed to accommodate several thousand applicants per year and targets six core attributes identified in a multi-method job-analysis study Aim To evaluate the predictive validity of selection methods for entry into postgraduate training, comprising a clinical problem-solving test, a situational judgement test, and a selection centre. Design and setting A three-part longitudinal predictive validity study of selection into training for UK general practice. Method In sample 1, participants were junior doctors applying for training in general practice (n = 6824). In sample 2, participants were GP registrars 1 year into training (n = 196). In sample 3, participants were GP registrars sitting the licensing examination after 3 years, at the end of training (n = 2292). The outcome measures include: assessor ratings of performance in a selection centre comprising job simulation exercises (sample 1); supervisor ratings of trainee job performance 1 year into training (sample 2); and licensing examination results, including an applied knowledge examination and a 12-station clinical skills objective structured clinical examination (OSCE; sample 3). Results Performance ratings at selection predicted subsequent supervisor ratings of job performance 1 year later. Selection results also significantly predicted performance on both the clinical skills OSCE and applied knowledge examination for licensing at the end of training. Conclusion In combination, these longitudinal findings provide good evidence of the predictive validity of the selection methods, and are the first reported for entry into postgraduate training. Results show that the best predictor of work performance and training outcomes is a combination of a clinical problem-solving test, a situational judgement test, and a selection centre. Implications for selection methods for all postgraduate specialties are considered. PMID:24267856

The predictive validity of selection for entry into postgraduate training in general practice: evidence from three longitudinal studies.

PubMed

Patterson, Fiona; Lievens, Filip; Kerrin, Máire; Munro, Neil; Irish, Bill

2013-11-01

The selection methodology for UK general practice is designed to accommodate several thousand applicants per year and targets six core attributes identified in a multi-method job-analysis study To evaluate the predictive validity of selection methods for entry into postgraduate training, comprising a clinical problem-solving test, a situational judgement test, and a selection centre. A three-part longitudinal predictive validity study of selection into training for UK general practice. In sample 1, participants were junior doctors applying for training in general practice (n = 6824). In sample 2, participants were GP registrars 1 year into training (n = 196). In sample 3, participants were GP registrars sitting the licensing examination after 3 years, at the end of training (n = 2292). The outcome measures include: assessor ratings of performance in a selection centre comprising job simulation exercises (sample 1); supervisor ratings of trainee job performance 1 year into training (sample 2); and licensing examination results, including an applied knowledge examination and a 12-station clinical skills objective structured clinical examination (OSCE; sample 3). Performance ratings at selection predicted subsequent supervisor ratings of job performance 1 year later. Selection results also significantly predicted performance on both the clinical skills OSCE and applied knowledge examination for licensing at the end of training. In combination, these longitudinal findings provide good evidence of the predictive validity of the selection methods, and are the first reported for entry into postgraduate training. Results show that the best predictor of work performance and training outcomes is a combination of a clinical problem-solving test, a situational judgement test, and a selection centre. Implications for selection methods for all postgraduate specialties are considered.

Successful selection of rainbow trout (Oncorhynchus mykiss) on their ability to grow with a diet completely devoid of fishmeal and fish oil, and correlated changes in nutritional traits

PubMed Central

Médale, Françoise; Larroquet, Laurence; Surget, Anne; Aguirre, Pierre; Kerneis, Thierry; Labbé, Laurent; Quillet, Edwige; Geurden, Inge; Skiba-Cassy, Sandrine; Dupont-Nivet, Mathilde

2017-01-01

In the context of limited marine resources, the exponential growth of aquaculture requires the substitution of fish oil and fishmeal, the traditional components of fish feeds by terrestrial plant ingredients. High levels of such substitution are known to negatively impact fish performance such as growth and survival in rainbow trout (Oncorhynchus mykiss) as in other salmonids. In this respect, genetic selection is a key enabler for improving those performances and hence for the further sustainable development of aquaculture. We selected a rainbow trout line over three generations for its ability to survive and grow on a 100% plant-based diet devoid of both fish oil and fishmeal (V diet) from the very first meal. In the present study, we compared the control line and the selected line after 3 generations of selection, both fed either the V diet or a marine resources-based diet (M diet). The objective of the study was to assess the efficiency of selection and the consequences on various correlated nutritional traits: feed intake, feed efficiency, digestibility, composition of whole fish, nutrient retention and fatty acid (FA) profile. We demonstrated that the genetic variability present in our rainbow trout population can be selected to improve survival and growth. The major result of the study is that after only three generations of selection, selected fish fed the V diet grew at the same rate as the control line fed the M diet, whilst the relative reduction of body weight was 36.8% before the selection. This enhanced performance on the V diet seems to be mostly linked to a higher feed intake for the selected fish. PMID:29059226

Psychological and Physiological Selection of Military Special Operations Forces Personnel (Selection psychologique et physiologique des militaires des forces d’operations speciales)

DTIC Science & Technology

2012-10-01

in the selection literature today is the Five Factor Model ( FFM ) or “Big 5” model of personality. This model includes: 1) Openness; 2...Conscientiousness; 3) Extraversion; 4) Agreeableness; and 5) Emotional Stability. Meta-analytic studies have found the FFM of personality to be predictive...is a self-report measure of the FFM that has demonstrated reliability and validity in numerous studies [18]. Another FFM measure, the Trait Self

Development of anion-selective membranes. [for energy storage

NASA Technical Reports Server (NTRS)

Lacey, R. E.; Cowsar, D. R.

1975-01-01

Methods were studied of preparing anion-exchange membranes that would have low resistance, high selectivity, and physical and chemical stability when used in acidic media in a redox energy storage system. Of the twelve systems selected for study, only the system that was based on crosslinked poly-4-vinylpyridinium chloride produced physically strong membranes when equilibrated in l M HCl. The resistivity of the best membrane was 12 ohm-cm, and the transference number for chloride ions was 0.81.

Input variable selection and calibration data selection for storm water quality regression models.

PubMed

Sun, Siao; Bertrand-Krajewski, Jean-Luc

2013-01-01

Storm water quality models are useful tools in storm water management. Interest has been growing in analyzing existing data for developing models for urban storm water quality evaluations. It is important to select appropriate model inputs when many candidate explanatory variables are available. Model calibration and verification are essential steps in any storm water quality modeling. This study investigates input variable selection and calibration data selection in storm water quality regression models. The two selection problems are mutually interacted. A procedure is developed in order to fulfil the two selection tasks in order. The procedure firstly selects model input variables using a cross validation method. An appropriate number of variables are identified as model inputs to ensure that a model is neither overfitted nor underfitted. Based on the model input selection results, calibration data selection is studied. Uncertainty of model performances due to calibration data selection is investigated with a random selection method. An approach using the cluster method is applied in order to enhance model calibration practice based on the principle of selecting representative data for calibration. The comparison between results from the cluster selection method and random selection shows that the former can significantly improve performances of calibrated models. It is found that the information content in calibration data is important in addition to the size of calibration data.

Development and Validation of the Motivations for Selection of Medical Study (MSMS) Questionnaire in India.

PubMed

Goel, Sonu; Angeli, Federica; Singla, Neetu; Ruwaard, Dirk

2016-01-01

Understanding medical students' motivation to select medical studies is particularly salient to inform practice and policymaking in countries-such as India-where shortage of medical personnel poses crucial and chronical challenges to healthcare systems. This study aims to develop and validate a questionnaire to assess the motivation of medical students to select medical studies. A Motivation for Selection of Medical Study (MSMS) questionnaire was developed using extensive literature review followed by Delphi technique. The scale consisted of 12 items, 5 measuring intrinsic dimensions of motivations and 7 measuring extrinsic dimensions. Exploratory factor analysis (EFA), confirmatory factor analysis (CFA), validity, reliability and data quality checks were conducted on a sample of 636 medical students from six medical colleges of three North Indian states. The MSMS questionnaire consisted of 3 factors (subscales) and 8 items. The three principal factors that emerged after EFA were the scientific factor (e.g. research opportunities and the ability to use new cutting edge technologies), the societal factor (e.g. job security) and the humanitarian factor (e.g. desire to help others). The CFA conducted showed goodness-of-fit indices supporting the 3-factor model. The three extracted factors cut across the traditional dichotomy between intrinsic and extrinsic motivation and uncover a novel three-faceted motivation construct based on scientific factors, societal expectations and humanitarian needs. This validated instrument can be used to evaluate the motivational factors of medical students to choose medical study in India and similar settings and constitutes a powerful tool for policymakers to design measures able to increase selection of medical curricula.

Selection is stronger in early-versus-late stages of divergence in a Neotropical livebearing fish.

PubMed

Ingley, Spencer J; Johnson, Jerald B

2016-03-01

How selection acts to drive trait evolution at different stages of divergence is of fundamental importance in our understanding of the origins of biodiversity. Yet, most studies have focused on a single point along an evolutionary trajectory. Here, we provide a case study evaluating the strength of divergent selection acting on life-history traits at early-versus-late stages of divergence in Brachyrhaphis fishes. We find that the difference in selection is stronger in the early-diverged population than the late-diverged population, and that trait differences acquired early are maintained over time. © 2016 The Author(s).

Propulsion for the lunar mission

NASA Technical Reports Server (NTRS)

Jones, Lee W.; Champion, Robert H., Jr.

1990-01-01

The paper describes the selection process utilized by NASA during the conduct of the 90-day study of the mission set that is known as the Space Exploration Initiative (SEI). It is directed specifically toward propulsion system definition and selection, with emphasis on the proposed Lunar Transfer Vehicle and the Lunar Exploration Vehicle. Results of trade studies show that selection cannot be readily made on the basis of engine performance alone, because the cost of launching hardware elements and the required propellant are very high. A decision must be made to use either life-cycle costs or annual program costs as the economic figure of merit, because they drive the selection in opposite directions.

Satellite Power Systems (SPS) concept definition study. Volume 2: SPS system requirements

NASA Technical Reports Server (NTRS)

Hanley, G.

1978-01-01

Collected data reflected the level of definition resulting from the evaluation of a broad spectrum of SPS (satellite power systems) concepts. As the various concepts matured, these requirements were updated to reflect the requirements identified for the projected satellite system/subsystem point design(s). The study established several candidate concepts which were presented to provide a basis for the selection of one or two approaches that would be given a more comprehensive examination. The two selected concepts were expanded and constitute the selected system point designs. The identified system/subsystem requirements was emphasized and information on the selected point design was provided.

Simulation and Experimental Studies on Grain Selection and Structure Design of the Spiral Selector for Casting Single Crystal Ni-Based Superalloy.

PubMed

Zhang, Hang; Xu, Qingyan

2017-10-27

Grain selection is an important process in single crystal turbine blades manufacturing. Selector structure is a control factor of grain selection, as well as directional solidification (DS). In this study, the grain selection and structure design of the spiral selector were investigated through experimentation and simulation. A heat transfer model and a 3D microstructure growth model were established based on the Cellular automaton-Finite difference (CA-FD) method for the grain selector. Consequently, the temperature field, the microstructure and the grain orientation distribution were simulated and further verified. The average error of the temperature result was less than 1.5%. The grain selection mechanisms were further analyzed and validated through simulations. The structural design specifications of the selector were suggested based on the two grain selection effects. The structural parameters of the spiral selector, namely, the spiral tunnel diameter ( d w ), the spiral pitch ( h b ) and the spiral diameter ( h s ), were studied and the design criteria of these parameters were proposed. The experimental and simulation results demonstrated that the improved selector could accurately and efficiently produce a single crystal structure.

Simulation and Experimental Studies on Grain Selection and Structure Design of the Spiral Selector for Casting Single Crystal Ni-Based Superalloy

PubMed Central

Zhang, Hang; Xu, Qingyan

2017-01-01

Grain selection is an important process in single crystal turbine blades manufacturing. Selector structure is a control factor of grain selection, as well as directional solidification (DS). In this study, the grain selection and structure design of the spiral selector were investigated through experimentation and simulation. A heat transfer model and a 3D microstructure growth model were established based on the Cellular automaton-Finite difference (CA-FD) method for the grain selector. Consequently, the temperature field, the microstructure and the grain orientation distribution were simulated and further verified. The average error of the temperature result was less than 1.5%. The grain selection mechanisms were further analyzed and validated through simulations. The structural design specifications of the selector were suggested based on the two grain selection effects. The structural parameters of the spiral selector, namely, the spiral tunnel diameter (dw), the spiral pitch (hb) and the spiral diameter (hs), were studied and the design criteria of these parameters were proposed. The experimental and simulation results demonstrated that the improved selector could accurately and efficiently produce a single crystal structure. PMID:29077067

Comparison of Mono-, Bi-, and Tripolar Configurations for Stimulation and Recording With an Interfascicular Interface.

PubMed

Nielsen, Thomas N; Sevcencu, Cristian; Struijk, Johannes J

2014-01-01

Previous studies have indicated that electrodes placed between fascicles can provide nerve recruitment with high topological selectivity if the areas of interest in the nerve are separated with passive elements. In this study, we investigated if this separation of fascicles also can provide topologically selective nerve recordings and compared the performance of mono-, bi-, and tripolar configurations for stimulation and recording with an intra-neural interface. The interface was implanted in the sciatic nerve of 10 rabbits and achieved a median selectivity of Ŝ=0.98-0.99 for all stimulation configurations, while recording selectivity configurations was in the range of Ŝ=0.70-0.80 with the monopolar configuration providing the lowest and the average reference configuration the highest recording selectivity. Interfascicular electrodes could provide an interesting addition to the bulk of peripheral nerve interfaces available for neural prosthetic devices. The separation of the nerve into chambers by the passive elements of the electrode could ensure a higher selectivity than comparable cuff electrodes and the intra-neural location could provide an option of targeting mainly central fascicles. Further studies are, however, still required to develop biocompatible electrodes and test their stability and safety in chronic experiments.

Cannabinoid receptor type 2 (CB2)-selective N-aryl-oxadiazolyl-propionamides: synthesis, radiolabelling, molecular modelling and biological evaluation

PubMed Central

2012-01-01

Background The endocannabinoid system is involved in many physiological and pathological processes. Two receptors (cannabinoid receptor type 1 (CB1) and type 2 (CB2)) are known so far. Many unwanted psychotic side effects of inhibitors of this system can be addressed to the interaction with CB1. While CB1 is one of the most abundant neuroreceptors, CB2 is expressed in the brain only at very low levels. Thus, highly potent and selective compounds for CB2 are desired. N-aryl-((hetero)aromatic)-oxadiazolyl-propionamides represent a promising class of such selective ligands for the human CB2. Here, a library of various derivatives is studied for suitable routes for labelling with 18F. Such 18F-labelled compounds can then be employed as CB2-selective radiotracers for molecular imaging studies employing positron emission tomography (PET). Results By varying the N-arylamide substructure, we explored the binding pocket of the human CB2 receptor and identified 9-ethyl-9H-carbazole amide as the group with optimal size. Radioligand replacement experiments revealed that the modification of the (hetero)aromatic moiety in 3-position of the 1,2,4-oxadiazoles shows only moderate impact on affinity to CB2 but high impact on selectivity towards CB2 with respect to CB1. Further, we could show by autoradiography studies that the most promising compounds bind selectively on CB2 receptors in mouse spleen tissue. Molecular docking studies based on a novel three-dimensional structural model of the human CB2 receptor in its activated form indicate that the compounds bind with the N-arylamide substructure in the binding pocket. 18F labelling at the (hetero)aromatic moiety at the opposite site of the compounds via radiochemistry was carried out. Conclusions The synthesized CB2-selective compounds have high affinity towards CB2 and good selectivity against CB1. The introduction of labelling groups at the (hetero)aromatic moiety shows only moderate impact on CB2 affinity, indicating the introduction of potential labelling groups at this position as a promising approach to develop CB2-selective ligands suitable for molecular imaging with PET. The high affinity for human CB2 and selectivity against human CB1 of the herein presented compounds renders them as suitable candidates for molecular imaging studies. PMID:23067874

34 CFR 650.20 - What are the selection procedures?

Code of Federal Regulations, 2011 CFR

2011-07-01

... selection of fellows. (b) Each year the Fellowship Board selects specific fields of study, and the number of fellows in each field (within the humanities, arts and social sciences), for which fellowships will be...

34 CFR 650.20 - What are the selection procedures?

Code of Federal Regulations, 2013 CFR

2013-07-01

... selection of fellows. (b) Each year the Fellowship Board selects specific fields of study, and the number of fellows in each field (within the humanities, arts and social sciences), for which fellowships will be...

34 CFR 650.20 - What are the selection procedures?

Code of Federal Regulations, 2010 CFR

2010-07-01

... selection of fellows. (b) Each year the Fellowship Board selects specific fields of study, and the number of fellows in each field (within the humanities, arts and social sciences), for which fellowships will be...