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Distribution by Scientific Domains
Medical Sciences48%
Life Sciences15%
Engineering6%
Chemistry5%
Business, Economics, Finance and Accounting4%
Polymers and Materials Science4%
Mathematics and Statistics3%
Psychology3%
Earth and Environmental Science2%
Humanities and Social Sciences2%
4 Other Domains8%

Kinds of Test

  • Ame test
  • Chi-squar test
  • Coomb test
  • Fisher exact test
  • Keul test
  • Kruskal-Walli test
  • Walli test
  • abdominal constriction test
  • ability test
  • abnormal liver function test
  • abnormal liver test
  • abnormal pap test
  • abnormal test
  • absorption test
  • accuracy test
  • accurate diagnostic test
  • accurate test
  • achievement test
  • acid amplification test
  • acid breath test
  • acid test
  • acth stimulation test
  • acth test
  • activation test
  • activity test
  • actual test
  • acute toxicity test
  • adaptive test
  • additional test
  • adhesion test
  • admission test
  • agar diffusion test
  • ageing test
  • agglutination test
  • aggregation test
  • aging test
  • allergy test
  • alternative test
  • amplification test
  • analysis test
  • animal test
  • anova test
  • antibody test
  • antigen test
  • antiglobulin test
  • application test
  • appropriate test
  • aptitude test
  • armitage trend test
  • article test
  • assessment test
  • assignment test
  • association test
  • asthma control test
  • asymptotic test
  • atopy patch test
  • attitude test
  • autologous serum skin test
  • autonomic function test
  • autonomic test
  • available test
  • avoidance test
  • balance test
  • basophil activation test
  • batch test
  • bedside test
  • behavioral test
  • behavioural test
  • bench test
  • benchmark test
  • bend test
  • bending test
  • bengal test
  • benton visual retention test
  • biaxial test
  • biochemical test
  • biological test
  • biomarker test
  • blind test
  • blood test
  • blue exclusion test
  • bmd test
  • bond strength test
  • bonferroni post hoc test
  • bonferroni test
  • break test
  • breath test
  • brief screening test
  • bronchial provocation test
  • bronchoprovocation test
  • bulimic investigatory test
  • calcium stimulation test
  • california verbal learning test
  • calorimeter test
  • capacity test
  • card sorting test
  • cardiopulmonary exercise test
  • causality test
  • cell test
  • centrifuge test
  • challenge test
  • chemistry test
  • chi-square test
  • chi-squared test
  • choice test
  • classical test
  • clinical test
  • clock drawing test
  • coagulation test
  • cochran-armitage test
  • cognitive ability test
  • cognitive function test
  • cognitive test
  • cointegration test
  • cold pressor test
  • colorimetric test
  • colour vision test
  • column test
  • combination test
  • combustion test
  • commercial test
  • common test
  • comparative test
  • comparison test
  • competition test
  • complementation test
  • comprehension test
  • comprehensive test
  • compression test
  • compressive test
  • computational test
  • concordance test
  • cone calorimeter test
  • cone penetration test
  • confirmation test
  • confirmatory test
  • consistent test
  • constriction test
  • consumer test
  • contact test
  • continuous performance test
  • contrast test
  • control test
  • conventional test
  • convergence test
  • correlation test
  • corrosion test
  • creep test
  • critical test
  • cross-sectional test
  • cross-validation test
  • crossmatch test
  • crucial test
  • culture test
  • cycle test
  • cyclic test
  • cycling test
  • cytotoxicity test
  • d-dimer test
  • d15 test
  • damage test
  • data unit root test
  • decongestion test
  • definitive test
  • degradation test
  • der test
  • design test
  • detection test
  • developmental test
  • dexamethasone suppression test
  • diagnostic test
  • difference test
  • different test
  • diffusion test
  • digestibility test
  • digit symbol substitution test
  • dilution test
  • direct antiglobulin test
  • direct shear test
  • direct test
  • discrimination test
  • disequilibrium test
  • disorders identification test
    		•
  • dissolution test
  • dna test
  • drawing test
  • driving test
  • drop test
  • drug test
  • duncan multiple range test
  • dunn test
  • dunnett test
  • dynamic test
  • earning test
  • eating attitude test
  • effective test
  • efficiency test
  • electrophysiological test
  • elevated plus-maze test
  • elisa test
  • empirical test
  • endurance test
  • equilibration test
  • evaluation test
  • exact test
  • excellent test
  • exclusion test
  • executive function test
  • exercise stress test
  • exercise test
  • existing test
  • experimental test
  • extensive test
  • f test
  • faecal occult blood test
  • fagerström test
  • false-positive test
  • fatigue test
  • fecal occult blood test
  • fertility test
  • field test
  • figure test
  • fire test
  • first empirical test
  • first test
  • fischer exact test
  • fisher exact test
  • fisher plsd test
  • fisher test
  • fitness test
  • flexion test
  • flick test
  • fluency test
  • fluid test
  • fluorescent antibody test
  • follow-up test
  • forced swim test
  • forced swimming test
  • fork test
  • formal test
  • formalin test
  • free recall test
  • friction test
  • friedman test
  • fuller test
  • function test
  • functional test
  • future test
  • g oral glucose tolerance test
  • general test
  • generalized likelihood ratio test
  • genetic test
  • genotypic test
  • germ tube test
  • global test
  • glucose challenge test
  • glucose test
  • glucose tolerance test
  • gold standard test
  • good test
  • goodness-of-fit test
  • granger causality test
  • groupe test
  • growth test
  • h test
  • h. pylori test
  • haematological test
  • hardness test
  • head-up tilt test
  • heating test
  • hemolysis test
  • histamine release test
  • hiv test
  • ho test
  • hoc test
  • hoc tukey test
  • homogeneity test
  • hot-plate test
  • hpv test
  • hsd test
  • hut test
  • hypo-osmotic swelling test
  • hypothesis test
  • i test
  • identification test
  • imaging test
  • imitative test
  • immersion test
  • immobilization test
  • immunofluorescence test
  • immunological test
  • impact test
  • implicit association test
  • important test
  • incremental exercise test
  • incremental test
  • indentation test
  • independent test
  • index test
  • indirect test
  • individual test
  • infiltration test
  • informative test
  • infusion test
  • inhibition test
  • initial test
  • injection test
  • inoculation test
  • instrumental imitative test
  • instrumental test
  • insulin tolerance test
  • integrity test
  • intelligence test
  • interaction test
  • international comparison test
  • intradermal test
  • intravenous glucose tolerance test
  • invasive test
  • investigatory test
  • involvement screening test
  • iq test
  • irritation test
  • jackknife test
  • joint test
  • judgment test
  • knowledge test
  • kruskal Walli test
  • laboratory test
  • laboratory toxicity test
  • language test
  • latency test
  • latex agglutination test
  • leaching test
  • learning test
  • levene test
  • life test
  • likelihood ratio test
  • likelihood-ratio test
  • liver function test
  • liver test
  • load test
  • loading test
  • log rank test
  • log-rank test
  • long-term test
  • low-dose dexamethasone suppression test
  • lsd test
  • lung function test
  • lymphocyte transformation test
  • making test
  • mann-whitney test
  • mann-whitney u test
  • mantel test
  • mantel-haenszel test
  • marker test
  • maze test
  • mcnemar test
  • meal test
  • meal tolerance test
  • mechanical test
  • memory test
  • mental test
  • methacholine challenge test
  • microbiological test
  • microhardness test
  • micronucleu test
    		•
  • microtensile bond strength test
  • model test
  • molecular test
  • monitoring test
  • morris water maze test
  • motor test
  • multiple choice test
  • multiple comparison test
  • multiple range test
  • multiple screening test
  • multiple sleep latency test
  • multiple test
  • multiple-choice test
  • multivariate test
  • mutagenicity test
  • naming test
  • nasal decongestion test
  • nasal provocation test
  • negative skin test
  • negative test
  • neurocognitive test
  • neurophysiological test
  • neuropsychological test
  • neutrality test
  • neutralization test
  • new diagnostic test
  • new test
  • no-choice test
  • non-invasive test
  • non-parametric test
  • non-stress test
  • noninvasive diagnostic test
  • noninvasive test
  • nonlinearity test
  • nonparametric statistical test
  • nonparametric test
  • normal test
  • novel test
  • nuclear test
  • nucleic acid amplification test
  • numerical test
  • objective test
  • occlusion test
  • occult blood test
  • oedema test
  • one test
  • open application test
  • open field test
  • open-field test
  • oral glucose tolerance test
  • oral provocation test
  • oscillatory shear test
  • other test
  • out-of-sample test
  • outcome test
  • oxidation test
  • p&g test
  • pad test
  • paired t test
  • panel data unit root test
  • panel test
  • panel unit root test
  • pap test
  • paper test
  • paper-and-pencil test
  • parametric test
  • partial mantel test
  • passive avoidance test
  • patch test
  • pathogenicity test
  • pcr test
  • peabody picture vocabulary test
  • pearson Chi-squar test
  • pearson chi-square test
  • pearson correlation test
  • pearson test
  • peel test
  • pegboard test
  • penetration test
  • performance test
  • peritoneal equilibration test
  • permeation test
  • permutation test
  • personality test
  • pharmacological test
  • phenotypic test
  • physical performance test
  • physiological test
  • picture vocabulary test
  • pilot test
  • platelet function test
  • plsd test
  • plus-maze test
  • positive direct antiglobulin test
  • positive patch test
  • positive pregnancy test
  • positive prick test
  • positive screening test
  • positive skin prick test
  • positive skin test
  • positive skin-prick test
  • positive test
  • post hoc test
  • post hoc tukey test
  • post test
  • post-hoc test
  • powerful test
  • practical test
  • predictive test
  • preference test
  • pregnancy test
  • preliminary test
  • pressor test
  • pressure test
  • previous test
  • prick test
  • primary screening test
  • primary test
  • probability test
  • proficiency test
  • progeny test
  • prognostic test
  • proliferation test
  • property test
  • proposed test
  • provocation test
  • provocative test
  • psa test
  • psychological test
  • psychometric test
  • pull test
  • pull-out test
  • pullout test
  • pulmonary function test
  • pumping test
  • punch test
  • puncture test
  • push-out test
  • pylori test
  • quality test
  • quantitative liver function test
  • quantitative test
  • radioallergosorbent test
  • randomization test
  • range test
  • rank correlation test
  • rank sum test
  • rank test
  • rank-sum test
  • rapid diagnostic test
  • rapid test
  • rapid urease test
  • ratio test
  • reading comprehension test
  • reading test
  • recall test
  • recognition test
  • recovery test
  • reduction test
  • reference test
  • regression test
  • relaxation test
  • release test
  • reliability test
  • reliable test
  • repeated test
  • resistance test
  • respiratory function test
  • response test
  • retention test
  • rheological test
  • rigorous test
  • robust test
  • robustness test
  • root test
  • rose bengal test
  • rotarod test
  • routine blood test
  • routine diagnostic test
  • routine laboratory test
  • rt-pcr test
  • salt spray test
  • same test
    		•
  • sample t test
  • sample test
  • scheffe test
  • scheffé test
  • schirmer test
  • science test
  • score test
  • scratch test
  • screening test
  • script concordance test
  • second test
  • selection test
  • sensation test
  • sensitive test
  • sensitivity test
  • sensory test
  • separate test
  • sequential test
  • serologic test
  • serological test
  • serum skin test
  • serum test
  • several test
  • shear test
  • short test
  • short-term test
  • sign rank test
  • sign test
  • signed rank test
  • signed-rank test
  • significance test
  • significant difference test
  • significant test
  • simple diagnostic test
  • simple test
  • simulation test
  • simultaneous test
  • single test
  • situational judgment test
  • skill test
  • skin prick test
  • skin test
  • skin-prick test
  • sleep latency test
  • slide test
  • slug test
  • smear test
  • smell identification test
  • smirnov test
  • social interaction test
  • soil test
  • solubility test
  • sorting test
  • spearman correlation test
  • spearman rank correlation test
  • spearman test
  • special test
  • specific test
  • specification test
  • speed test
  • spot test
  • spray test
  • square test
  • stability test
  • stand-alone test
  • standard laboratory test
  • standard test
  • standardised test
  • standardized test
  • stationarity test
  • statistical test
  • step test
  • stimulation test
  • stool antigen test
  • stool test
  • strength test
  • stress test
  • stringent test
  • stroop test
  • student t test
  • study test
  • subjective test
  • subsequent test
  • substance involvement screening test
  • substitution test
  • sum test
  • suppression test
  • susceptibility test
  • suspension test
  • sweat test
  • sweep test
  • swelling test
  • swim test
  • swimming test
  • symbol substitution test
  • systematic test
  • table test
  • tail flick test
  • tail suspension test
  • tapping test
  • taste test
  • tear test
  • tensile test
  • tension test
  • thermal test
  • thinprep pap test
  • third test
  • three-point bending test
  • threshold test
  • thyroid function test
  • tilt test
  • time test
  • to test
  • tolerance test
  • toxicity test
  • toxicology test
  • tracer test
  • trail making test
  • transformation test
  • transmission disequilibrium test
  • transmission test
  • transmission-disequilibrium test
  • treadmill exercise test
  • treadmill test
  • trend test
  • triangle test
  • triaxial test
  • triple test
  • trypan blue exclusion test
  • tube test
  • tuberculin skin test
  • tukey hsd test
  • tukey post hoc test
  • tukey test
  • two-tailed fisher exact test
  • u test
  • ul-94 test
  • unconditional test
  • uniaxial compression test
  • uniaxial tensile test
  • unit root test
  • univariate test
  • urea breath test
  • urease test
  • urine test
  • urodynamic test
  • used test
  • useful screening test
  • useful test
  • valid test
  • validation test
  • validity test
  • valuable test
  • various test
  • verbal fluency test
  • verbal learning test
  • vibration test
  • vision test
  • visual field test
  • visual retention test
  • vitro test
  • vivo test
  • vocabulary test
  • wada test
  • wakefulness test
  • wald test
  • walk test
  • walking test
  • water maze test
  • wear test
  • whitney test
  • whitney u test
  • wilcoxon rank sum test
  • wilcoxon rank-sum test
  • wilcoxon sign rank test
  • wilcoxon signed-rank test
  • wilcoxon test
  • wisconsin card sorting test
  • word association test
  • writhing test

    • Terms modified by Test

  • test abnormality
  • test accuracy
  • test agent
  • test alone
  • test analysis
  • test analyte
  • test animals
  • test anxiety
  • test apparatus
  • test application
  • test approach
  • test area
  • test article
  • test available
  • test bacteria
  • test battery
  • test body
  • test calculation
  • test case
  • test cell
  • test chamber
  • test characteristic
  • test chemical
  • test compound
  • test concentration
  • test condition
  • test content
  • test data
  • test data set
  • test dataset
  • test day
  • test design
  • test developers
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  • test device
  • test diet
  • test dose
  • test drug
  • test duration
    		•
  • test endpoint
  • test environment
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  • test evaluation
  • test example
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  • test for children
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  • test instructions
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  • test mixture
  • test model
  • test network
  • test object
  • test only
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  • test outcome
    		•
  • test p
  • test panel
  • test parameter
  • test particle
  • test patient
  • test pattern
  • test performance
  • test period
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    		•
  • test series
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  • test used
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    • Selected Abstracts

    SELF-CONTROL, SOCIAL BONDS, AND DESISTANCE: A TEST OF LIFE-COURSE INTERDEPENDENCE

    CRIMINOLOGY, Issue 4 2006
    Article first published online: 11 DEC 200, ELAINE EGGLESTON DOHERTY
    Theoretical debates and empirical tests on the explanation of stability and change in offending over time have been ongoing for over a decade pitting Gottfredson and Hirschi's (1990) criminal propensity model against Sampson and Laub's (1993) life-course model of informal social control. In 2001, Wright and his colleagues found evidence of a moderating relationship between criminal propensity, operationalized as self-control, and prosocial ties on crime, a relationship they term life-course interdependence. The current study extends their research by focusing on this moderating relationship and the developmental process of desistance from crime among serious juvenile delinquents. Contrary to the life-course interdependence hypothesis, the results indicate that whereas self-control and social bonds are strongly related to desistance from crime, there is no evidence of a moderating relationship between these two factors on desistance among this sample. The implications of this research for life-course theories of crime, future research, and policies regarding desistance are discussed. [source]

    SOCIAL SUPPORT, INEQUALITY, AND HOMICIDE: A CROSS-NATIONAL TEST OF AN INTEGRATED THEORETICAL MODEL,

    CRIMINOLOGY, Issue 3 2003
    TRAVIS C. PRATT
    Social support, institutional anomie, and macrolevel general strain perspectives have emerged as potentially important explanations of aggregate levels of crime. Drawing on insights from each of these perspectives in a cross-national context, the analyses show that 1) our measure of social support is inversely related to homicide rates, 2) economic inequality also maintains a direct relationship with homicide rates, and 3) social support significantly interacts with economic inequality to influence homicide rates. The implications of the analysis for ongoing discourse concerning the integration of these criminological theories and the implications for the development of effective crime control policies are discussed. [source]

    EXAMINING THE CONDITIONAL NATURE OF THE ILLICIT DRUG MARKET-HOMICIDE RELATIONSHIP: A PARTIAL TEST OF THE THEORY OF CONTINGENT CAUSATION

    CRIMINOLOGY, Issue 1 2002
    GRAHAM C. OUSEY
    Recently, Zimring and Hawkins (1997) have suggested that drug markets are a "contingent cause" of the increase in homicide rates. That is, where structural conditions known to produce violence are already in place, the drug distribution-homicide link may be exacerbated. This analysis uses hierarchical linear modeling to investigate two key research questions: (1) Is within-city variation in illicit drug market activity positively associated with within-city variation in homicide rates during the 1984,1997 period? (2) Is the illicit drug market-homicide association contingent on preexisting violence conducive socioeconomic conditions? Using three measures of drug market activity, analyses provide affirmative evidence on both questions. Theoretical and research implications of these findings are discussed. [source]

    MODELING MEDIATION IN THE ETIOLOGY OF VIOLENT BEHAVIOR IN ADOLESCENCE: A TEST OF THE SOCIAL DEVELOPMENT MODEL,

    CRIMINOLOGY, Issue 1 2001
    BU HUANG
    The social development model seeks to explain human behavior through specification of predictive and mediating developmental relationships. It incorporates the effects of empirical predictors ("risk factors" and "protective factors") for antisocial behavior and seeks to synthesize the most strongly supported propositions of control theory, social learning theory, and differential association theory. This article examines the fit of the social development model using constructs measured at ages 10, 13, 14, and 16 to predict violent behavior at age 18. The sample of 808 is from the longitudinal panel of the Seattle Social Development Project, which in 1985 surveyed fifth-grade students from schools serving high crime neighborhoods in Seattle, Washington. Structural equation modeling techniques were used to examine the fit of the model to the data. The model fit the data (CFI ,.90, RMSEA ,.05). We conclude that the social development model adequately predicts violence at age 18 and mediates much of the effect of prior violence. Implications for theory and for prevention are discussed. [source]

    MODIFIED ENDOSCOPIC CONGO RED TEST: A RAPID METHOD TO VISUALIZE GASTRIC ACID SECRETION

    DIGESTIVE ENDOSCOPY, Issue 1 2003
    Ervin Tóth
    Background:, The conventional endoscopic Congo red test (CRT) permits visualization of acid-producing mucosa. However, the CRT has not been disseminated into clinical endoscopy, which is partly due to the substantial prolongation of the gastroscopic examination. Methods:, Five healthy volunteers and 551 patients were included in a study designed to develop a more rapid approach based on the CRT. In this modified endoscopic Congo red test (MCRT), 0.2 µg/kg of pentagastrin was given intravenously to stimulate gastric acid production. The technical feasibility, tolerability, reproducibility, and inter- and intra-observer reliability of the MCRT were evaluated. Results:, The MCRT was as effective as the CRT (i.e. 6 µg/kg of pentagastrin was administered intramuscularly) in visualizing the extent of acid-producing gastric mucosa. Moreover, the MCRT significantly reduced the duration of examination by 63% (almost 8 min), compared to the CRT. Conclusions:, This MCRT is a simple, inexpensive, well-tolerated and reproducible method with low inter- and intra-observer variability and is well suited for endoscopy units with high workloads. [source]

    AN EXPERIMENTAL TEST ON RETIREMENT DECISIONS

    ECONOMIC INQUIRY, Issue 3 2007
    ENRIQUE FATAS
    As part of the current debate on the reform of pension systems, this paper presents an original experimental test where subjects face three different payoff sequences with identical expected value. Two central questions are analyzed. First, whether the distribution of retirement benefits across time influences the retirement decision. And second, whether actuarially fair pension systems distort the retirement decision. The results indicate both that a lump-sum payment rather than annuity benefits is far more effective in delaying the retirement decision and that recent reforms that encourage the link between lifetime contributions and pension benefits to delay the retirement decision should take into account timing considerations. (JEL C91, H55, J26) [source]

    A COMPARISON OF THE FAGERSTRÖM TEST FOR NICOTINE DEPENDENCE AND SMOKING PREVALENCE ACROSS COUNTRIES: UPDATED DATA FROM SPAIN

    ADDICTION, Issue 2 2009
    MARCELA FU
    No abstract is available for this article. [source]

    A TEST OF THE NEUTRAL MODEL OF EXPRESSION CHANGE IN NATURAL POPULATIONS OF HOUSE MOUSE SUBSPECIES

    EVOLUTION, Issue 2 2010
    Fabian Staubach
    Changes in expression of genes are thought to contribute significantly to evolutionary divergence. To study the relative role of selection and neutrality in shaping expression changes, we analyzed 24 genes in three different tissues of the house mouse (Mus musculus). Samples from two natural populations of the subspecies M. m. domesticus and M. m. musculus were investigated using quantitative PCR assays and sequencing of the upstream region. We have developed an approach to quantify expression polymorphism within such populations and to disentangle technical from biological variation in the data. We found a correlation between expression polymorphism within populations and divergence between populations. Furthermore, we found a correlation between expression polymorphism and sequence polymorphism of the respective genes. These data are most easily interpreted within a framework of a predominantly neutral model of gene expression change, where only a fraction of the changes may have been driven by positive selection. Although most genes investigated were expressed in all three tissues analyzed, significant changes of expression levels occurred predominantly in a single tissue only. This adds to the notion that enhancer-specific effects or transregulatory effects can modulate the evolution of gene expression in a tissue-specific way. [source]

    UNEXPLAINED SPLIT SEX RATIOS IN THE NEOTROPICAL PLANT-ANT, ALLOMERUS OCTOARTICULATUS VAR. DEMERARAE (MYRMICINAE): A TEST OF HYPOTHESES

    EVOLUTION, Issue 1 2010
    Gabriel D. G. Debout
    We investigated sex allocation in the Neotropical ant Allomerus octoarticulatus var. demerarae. Because Allomerus is a plant symbiont, we could make geographically extensive collections of complete colonies and of foundresses in saplings, allowing us to estimate not only population- and colony-level sex allocation but also colony resource levels and the relatednesses of competing ant foundresses. This species exhibits a strongly split sex ratio, with 80% of mature colonies producing ,90% of one sex or the other. Our genetic analyses (DNA microsatellites) reveal that Allomerus has a breeding system characterized by almost complete monogyny and a low frequency of polyandry. Contrary to theoretical explanations, we find no difference in worker relatedness asymmetries between female- and male-specialist colonies. Furthermore, no clear link was found between colony sex allocation and life history traits such as the number of mates per queen, or colony size, resource level, or fecundity. We also failed to find significant support for male production by workers, infection by Wolbachia, local resource competition, or local mate competition. We are left with the possibility that Allomerus exhibits split sex ratios because of the evolution of alternative biasing strategies in queens or workers, as recently proposed in the literature. [source]

    DENSITY DEPENDENCE AND COOPERATION: THEORY AND A TEST WITH BACTERIA

    EVOLUTION, Issue 9 2009
    Adin Ross-Gillespie
    Although cooperative systems can persist in nature despite the potential for exploitation by noncooperators, it is often observed that small changes in population demography can tip the balance of selective forces for or against cooperation. Here we consider the role of population density in the context of microbial cooperation. First, we account for conflicting results from recent studies by demonstrating theoretically that: (1) for public goods cooperation, higher densities are relatively unfavorable for cooperation; (2) in contrast, for self-restraint,type cooperation, higher densities can be either favorable or unfavorable for cooperation, depending on the details of the system. We then test our predictions concerning public goods cooperation using strains of the pathogenic bacterium Pseudomonas aeruginosa that produce variable levels of a public good,iron-scavenging siderophore molecules. As predicted, we found that the relative fitness of cheats (under-producers) was greatest at higher population densities. Furthermore, as assumed by theory, we show that this occurs because cheats are better able to exploit the cooperative siderophore production of other cells when they are physically closer to them. [source]

    A TEST AND REVIEW OF THE ROLE OF EFFECTIVE POPULATION SIZE ON EXPERIMENTAL SEXUAL SELECTION PATTERNS

    EVOLUTION, Issue 7 2009
    Rhonda R. Snook
    Experimental evolution, particularly experimental sexual selection in which sexual selection strength is manipulated by altering the mating system, is an increasingly popular method for testing evolutionary theory. Concerns have arisen regarding genetic diversity variation across experimental treatments: differences in the number and sex ratio of breeders (effective population size; Ne) and the potential for genetic hitchhiking, both of which may cause different levels of genetic variation between treatments. Such differences may affect the selection response and confound interpretation of results. Here we use both census-based estimators and molecular marker-based estimates to empirically test how experimental evolution of sexual selection in Drosophila pseudoobscura impacts Ne and autosomal genetic diversity. We also consider effects of treatment on X-linked Nes, which have previously been ignored. Molecular autosomal marker-based estimators indicate that neither Ne nor genetic diversity differs between treatments experiencing different sexual selection intensities; thus observed evolutionary responses reflect selection rather than any confounding effects of experimental design. Given the increasing number of studies on experimental sexual selection, we also review the census Nes of other experimental systems, calculate X-linked Ne, and compare how different studies have dealt with the issues of inbreeding, genetic drift, and genetic hitchhiking to help inform future designs. [source]

    PHENOTYPIC PLASTICITY OF HERMAPHRODITE SEX ALLOCATION PROMOTES THE EVOLUTION OF SEPARATE SEXES: AN EXPERIMENTAL TEST OF THE SEX-DIFFERENTIAL PLASTICITY HYPOTHESIS USING SAGITTARIA LATIFOLIA (ALISMATACEAE)

    EVOLUTION, Issue 4 2008
    Marcel E. Dorken
    Separate sexes can evolve under nuclear inheritance when unisexuals have more than twice the reproductive fitness of hermaphrodites through one sex function (e.g., when females have more than twice the seed fertility of hermaphrodites). Because separate sexes are thought to evolve most commonly via a gynodioecious intermediate (i.e., populations in which females and hermaphrodites cooccur), the conditions under which females can become established in populations of hermaphrodites are of considerable interest. It has been proposed that resource-poor conditions could promote the establishment of females if hermaphrodites are plastic in their sex allocation and allocate fewer resources to seed production under these conditions. If this occurs, the seed fertility of females could exceed the doubling required for the evolution of unisexuality under low-, but not high-resource conditions (the sex-differential plasticity hypothesis). We tested this hypothesis using replicate experimental arrays of the aquatic herb Sagittaria latifolia grown under two fertilizer treatments. The results supported the sex-differential plasticity hypothesis, with females having more than twice the seed fertility of hermaphrodites under low-, but not high-fertilizer conditions. Our findings are consistent with the idea that separate sexes are more likely to evolve under unfavorable conditions. [source]

    AN INTERSPECIFIC TEST OF ALLEN'S RULE: EVOLUTIONARY IMPLICATIONS FOR ENDOTHERMIC SPECIES

    EVOLUTION, Issue 12 2007
    R. L. Nudds
    Ecogeographical rules provide potential to describe how organisms are morphologically constrained to climatic conditions. Allen's rule (relatively shorter appendages in colder environments) remains largely unsupported and there remains much controversy whether reduced surface area of appendages provides energetic savings sufficient to make this morphological trend truly adaptive. By showing for the first time that Allen's rule holds for closely related endothermic species, we provide persuasive support of the adaptive significance of this trend for multiple species. Our results indicate that reduction of thermoregulatory cost during the coldest part of the breeding season is the most likely mechanism driving Allen's rule for these species. Because for 54% of seabird species examined, rise in seasonal maximum temperature over 100 years will exceed that for minimum temperatures, an evolutionary mismatch will arise between selection for limb length reduction and ability to accommodate heat stress. [source]

    EVOLUTION OF BIRD SONG AFFECTS SIGNAL EFFICACY: AN EXPERIMENTAL TEST USING HISTORICAL AND CURRENT SIGNALS

    EVOLUTION, Issue 8 2007
    Elizabeth P. Derryberry
    Mating signals act as behavioral barriers to gene flow in many animal taxa, yet little is known about how signal evolution within populations contributes to the formation of these barriers. Although variation in mating signals among populations is known to affect mating behavior, there is no direct evidence that the evolution of mating signals changes signal effectiveness within a natural population. Making use of historical recordings of bird song, I found that both male and female white-crowned sparrows (Zonotrichia leucophrys) respond more strongly to current than to historical songs, indicating that historical songs are less effective as signals in the current contexts of both mate choice and male,male competition. Finding that historical signals are less effective suggests that signal evolution within populations may ultimately contribute to the formation of behavioral barriers to gene flow between populations. [source]

    MICRO- AND MACROEVOLUTIONARY DECOUPLING OF CICHLID JAWS: A TEST OF LIEM'S KEY INNOVATION HYPOTHESIS

    EVOLUTION, Issue 10 2006
    C. D. Hulsey
    Abstract The extent to which elements of functional systems can change independently (modularity) likely influences the diversification of lineages. Major innovations in organismal design, like the pharyngeal jaw in cichlid fishes, may be key to a group's success when they relax constraints on diversification by increasing phenotypic modularity. In cichlid fishes, pharyngeal jaw modifications that enhanced the ability to breakdown prey may have freed their oral jaws from serving their ancestral dual role as a site of both prey capture and prey processing. This functional decoupling that allowed the oral jaws to become devoted solely to prey capture has been hypothesized to have permitted the two sets of cichlid jaws to evolve independently. We tested the hypothesis that oral and pharyngeal jaw mechanics are evolutionarily decoupled both within and among Neotropical Heroine cichlids. In the trophically polymorphic species Herichthys minckleyi, molariforms that exhibit enlarged molarlike pharyngeal jaw teeth were found to have approximately 400% greater lower jaw mass compared to H. minckleyi with the alternative papilliform pharyngeal morphology. However, oral jaw gape, lower jaw velocity ratios, anterior jaw linkage mechanics, and jaw protrusion did not differ between the morphotypes. In 40 other Heroine species, there was a weak correlation between oral jaw mechanics and pharyngeal jaw mass when phylogenetic history was ignored. Yet, after expansion of the cytochrome b phylogeny for Heroines, change in oral jaw mechanics was found to be independent of evolutionary change in pharyngeal jaw mass based on independent contrasts. Evolutionary decoupling of oral and pharyngeal jaw mechanics has likely played a critical role in the unparalleled trophic diversification of cichlid fishes. [source]

    A TEST OF WORKER POLICING THEORY IN AN ADVANCED EUSOCIAL WASP, VESPULA RUFA

    EVOLUTION, Issue 6 2005
    T. Wenseleers
    Abstract Mutual policing is an important mechanism for maintaining social harmony in group-living organisms. In some ants, bees, and wasps, workers police male eggs laid by other workers in order to maintain the reproductive primacy of the queen. Kin selection theory predicts that multiple mating by the queen is one factor that can selectively favor worker policing. This is because when the queen is mated to multiple males, workers are more closely related to queen's sons than to the sons of other workers. Here we provide an additional test of worker policing theory in Vespinae wasps. We show that the yellowjacket Vespula rufa is characterized by low mating frequency, and that a significant percentage of the males are workers' sons. This supports theoretical predictions for paternities below 2, and contrasts with other Vespula species, in which paternities are higher and few or no adult males are worker produced, probably due to worker policing, which has been shown in one species, Vespula vulgaris. Behavioral observations support the hypothesis that V. rufa has much reduced worker policing compared to other Vespula. In addition, a significant proportion of worker-laid eggs were policed by the queen. [source]

    A STATISTICAL TEST OF UNBIASED EVOLUTION OF BODY SIZE IN BIRDS

    EVOLUTION, Issue 12 2002
    Folmer Bokma
    Abstract., Of the approximately 9500 bird species, the vast majority is small-bodied. That is a general feature of evolutionary lineages, also observed for instance in mammals and plants. The avian interspecific body size distribution is right-skewed even on a logarithmic scale. That has previously been interpreted as evidence that body size evolution has been biased. However, a procedure to test for unbiased evolution from the shape of body size distributions was lacking. In the present paper unbiased body size evolution is defined precisely, and a statistical test is developed based on Monte Carlo simulation of unbiased evolution. Application of the test to birds suggests that it is highly unlikely that avian body size evolution has been unbiased as defined. Several possible explanations for this result are discussed. A plausible explanation is that the general model of unbiased evolution assumes that population size and generation time do not affect the evolutionary variability of body size; that is, that micro- and macroevolution are decoupled, which theory suggests is not likely to be the case. [source]

    ADAPTIVE CONSTRAINTS AND THE PHYLOGENETIC COMPARATIVE METHOD: A COMPUTER SIMULATION TEST

    EVOLUTION, Issue 1 2002
    Emilia P. Martins
    Abstract Recently, the utility of modern phylogenetic comparative methods (PCMs) has been questioned because of the seemingly restrictive assumptions required by these methods. Although most comparative analyses involve traits thought to be undergoing natural or sexual selection, most PCMs require an assumption that the traits be evolving by less directed random processes, such as Brownian motion (BM). In this study, we use computer simulation to generate data under more realistic evolutionary scenarios and consider the statistical abilities of a variety of PCMs to estimate correlation coefficients from these data. We found that correlations estimated without taking phylogeny into account were often quite poor and never substantially better than those produced by the other tested methods. In contrast, most PCMs performed quite well even when their assumptions were violated. Felsenstein's independent contrasts (FIC) method gave the best performance in many cases, even when weak constraints had been acting throughout phenotypic evolution. When strong constraints acted in opposition to variance-generating (i.e., BM) forces, however, FIC correlation coefficients were biased in the direction of those BM forces. In most cases, all other PCMs tested (phylogenetic generalized least squares, phylogenetic mixed model, spatial autoregression, and phylogenetic eigenvector regression) yielded good statistical performance, regardless of the details of the evolutionary model used to generate the data. Actual parameter estimates given by different PCMs for each dataset, however, were occasionally very different from one another, suggesting that the choice among them should depend on the types of traits and evolutionary processes being considered. [source]

    EXPERIMENTAL AIDED PERFORMANCE EVALUATION METHODS FOR WAFER PROBE TEST

    EXPERIMENTAL TECHNIQUES, Issue 5 2006
    D.S. Liu
    First page of article [source]

    FIVE TIMES SIT TO STAND TEST IS A PREDICTOR OF RECURRENT FALLS IN HEALTHY COMMUNITY-LIVING SUBJECTS AGED 65 AND OLDER

    JOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 8 2008
    Severine Buatois PhD
    No abstract is available for this article. [source]

    USE OF THE AUTOMATIC CLOCK DRAWING TEST TO RAPIDLY SCREEN FOR COGNITIVE IMPAIRMENT IN OLDER ADULTS, DRIVERS, AND THE PHYSICALLY CHALLENGED

    JOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 2 2007
    Sandy Helene Straus MS
    No abstract is available for this article. [source]

    WEAR RESISTANCE OF PACKABLE RESIN COMPOSITES AFTER SIMULATED TOOTHBRUSHING TEST

    JOURNAL OF ESTHETIC AND RESTORATIVE DENTISTRY, Issue 5 2004
    Thomas J. Hilton DMD
    [source]

    DRYING EFFECTS OF TWO AIR-DRYING SHELTERS IN A PILOT TEST ON SULTANA GRAPES

    JOURNAL OF FOOD PROCESS ENGINEERING, Issue 1 2010
    LINGLING LI
    ABSTRACT The drying effects of sultana grapes in two different air-drying shelters were tested and analyzed. Ten different thin-layer drying mathematical models were compared according to their coefficients of determination and,2test. The Wang and Singh model was found to be the most suitable for describing the air-drying curves of sultana grapes. As compared with the local traditional shelter, the reformed shelter with a greenhouse can reduce about 12,18% of air-drying time, increase about 23% in green-grade rate of raisins and increase 33% in the effective moisture diffusivity of sultana grapes. PRACTICAL APPLICATIONS Grapes are one of the most popular and palatable fruits in the world. The preservation of grapes by drying is a major industry in many parts of the world where grapes are grown. Drying grapes, either by open sun drying, shade drying or mechanical drying, produces raisins. Air-drying of solar energy has been demonstrated to be cost-effective and could be an effective alternative to traditional and mechanical drying systems, especially in locations with good sunshine during the harvest season. The traditional air-drying shelter of grapes has been used for thousands of years in Asia and other places around the world. However, less investigation was done about the drying characteristics and the optimization of the shelter. The work of this manuscript provides interesting information that is useful for design of the drying shelter of raisins and for the improvement of raisin quality, especially using air-drying of solar energy. [source]

    SCALE-UP and FIELD TEST of the VACUUM/STEAM/VACUUM SURFACE INTERVENTION PROCESS FOR POULTRY,

    JOURNAL OF FOOD PROCESS ENGINEERING, Issue 5 2003
    MICHAEL KOZEMPEL
    ABSTRACT The Vacuum/Steam/Vacuum surface intervention pilot plant processor was scaled up to a mobile unit that can be transported to close proximity of chicken processing plants. After several modifications to the mandrel that supports the broiler carcass in the treatment chamber to minimize mechanical damage, the unit was capable of 1.1 log cfu/mL kill of inoculated Listeria innocua and 1.4 log cfu/mL kill of inoculated E. coli K-12. Field tests achieved 1.4 log kill of E. coli and 1.2 log kill of Campylobacter on freshly processed chicken using 3 cycles and 138C saturated steam. But, there was extensive mechanical damage. the mandrel was modified in the Eastern Regional Research Center pilot plant to eliminate the mechanical damage. With mechanical damage eliminated, the bacteria kill was 1.1,1.5 log of inoculated E. coli K-12 with a total process time of 1.1 s. [source]

    VIRULENCE LEVELS OF BIOFILM-GROWN LISTERIA MONOCYTOGENES LO28 ARE LOWER THAN THOSE OF PLANKTONIC CELLS IN AN ORAL INOCULATION TEST ON MICE

    JOURNAL OF FOOD SAFETY, Issue 1 2007
    ETIENNE ZUNDEL
    ABSTRACT The aim of this study was to produce Listeria monocytogenes biofilms suitable for virulence assays and to determine whether the released bacteria had the same virulence potential as their planktonic counterparts. Biofilms of Listeria monocytogenes LO28 strain, with or without Sphingomonas paucimobilis CCL10 strain, containing up to 7 log10 cfu/cm2 were produced in polypropylene syringes. The virulence of strain LO28 was analyzed in mice after intravenous, subcutaneous and oral inoculation. Its virulence level in binary cultures was not significantly different from that of monocultures. L. monocytogenes LO28 virulence in biofilms was lower than that of their planktonic counterparts after oral inoculation. Our results suggest that biofilms pose no greater health risk to the consumer than planktonic bacteria. [source]

    DETERMINATION OF COOLNESS AND DAMPNESS SENSATIONS CREATED BY FABRICS BY FOREARM TEST AND FABRIC MEASUREMENTS

    JOURNAL OF SENSORY STUDIES, Issue 4 2009
    SIBEL KAPLAN
    ABSTRACT Clothing is continuously in an interaction with the body both thermally and mechanically. Different sensations constituting the comfort status of a person arise as a result of this interaction. Coolness sensation perceived during skin-fabric contact is one of these sensations arising from the transient heat flow from skin to the fabric as skin is usually warmer than clothing. In this study, coolness to touch and dampness sensations created by knitted fabrics having different compositions and physical surface characteristics were investigated by forearm test conducted on seven males. Besides physical properties (weight, yarn count, thickness, density), surface roughness and friction properties of the inner surfaces of the fabrics touching the skin were also determined. Microscopic photographs were taken to have an idea about hairiness properties of the inner surfaces and optical porosity values were calculated by analysis of the microscopic images by using MATLAB software. It was found out that coolness and dampness sensations arise during skin,fabric contact are mostly related to the permeability and surface roughness characteristics of fabrics, and the effect of fabric material is more on dampness sensation than coolness sensation. PRACTICAL APPLICATIONS In the recent years, consumers pay attention more to the mechanical, thermal and visual sensations stimulated by the dynamic body,clothing interactions besides the aesthetic properties of their clothing. They take into consideration feelings they have during first touch with the clothing into their purchase decisions. Coolness to touch sensation perceived during first contact with the fabric and dampness sensation , which is very important during wear conditions including sweating , are two of them and they are related to the thermophysiological aspect of clothing comfort. For producing garments giving desirable feelings, it is very important to determine fabric properties influencing these sensations. A subjective evaluation method , the forearm test , was used to find out the relationships between coolness and dampness sensations and fabric properties. Results of this study are thought to be beneficial data for fabric manufacturers aiming to produce clothing for specific end users. [source]

    APPLICATION OF A COMPRESSION-RELAXATION TEST FOR THE CHARACTERIZATION OF BURLAT SWEET CHERRY

    JOURNAL OF TEXTURE STUDIES, Issue 1 2001
    PEDRO L. MARQUINA
    Mechanical parameters of Burlat sweet cherries (Prunus avium) were studied as a function of ripening during three consecutive years by using a penetration test, a compression test between two plates, and a compression-relaxation test. The latter yields the "apparent secant modulus," i. e. the ratio of the initial maximum compression force over the applied strain. This modulus is one of the most useful mechanical parameters to discriminate between batches because its value is clearly related to the variety and degree of ripeness. Thus, the compression-relaxation test consistently allowed the differentiation of cherries in five degrees of ripeness. [source]

    EVALUATION OF A STREAM AQUIFER ANALYSIS TEST USING ANALYTICAL SOLUTIONS AND FIELD DATA,

    JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 3 2004
    Garey A. Fox
    ABSTRACT: Considerable advancements have been made in the development of analytical solutions for predicting the effects of pumping wells on adjacent streams and rivers. However, these solutions have not been sufficiently evaluated against field data. The objective of this research is to evaluate the predictive performance of recently proposed analytical solutions for unsteady stream depletion using field data collected during a stream/aquifer analysis test at the Tamarack State Wildlife Area in eastern Colorado. Two primary stream/aquifer interactions exist at the Tamarack site: (1) between the South Platte River and the alluvial aquifer and (2) between a backwater stream and the alluvial aquifer. A pumping test is performed next to the backwater stream channel. Drawdown measured in observation wells is matched to predictions by recently proposed analytical solutions to derive estimates of aquifer and streambed parameters. These estimates are compared to documented aquifer properties and field measured streambed conductivity. The analytical solutions are capable of estimating reasonable values of both aquifer and streambed parameters with one solution capable of simultaneously estimating delayed aquifer yield and stream flow recharge. However, for long term water management, it is reasonable to use simplified analytical solutions not concerned with early-time delayed yield effects. For this site, changes in the water level in the stream during the test and a varying water level profile at the beginning of the pumping test influence the application of the analytical solutions. [source]

    RENIN STIMULATION TEST: A SIMPLE DIAGNOSTIC TEST FOR HYPERALDOSTERONISM

    NEPHROLOGY, Issue 3 2000
    Penny Mj
    [source]

    TEST OF A MULTISTAGE MODEL OF DISTAL AND PROXIMAL ANTECEDENTS OF LEADER PERFORMANCE

    PERSONNEL PSYCHOLOGY, Issue 3 2009
    CHAD H. VAN IDDEKINGE
    The authors developed and tested a multistage model of distal and proximal predictors of leader performance in an effort to shed greater light on the intermediate linkages between broad leader traits and performance. Predictor and criterion data were obtained from 471 noncommissioned officers in the U.S. Army. A model with cognitive ability and 3 of the Big 5 personality factors as distal antecedents, leadership experiences and motivation to lead as semidistal antecedents, and the knowledge, skills, and ability (KSAs) to lead as proximal antecedents of leader performance provided a good fit to the data. More specifically, the effects of the distal and semidistal antecedents on leader performance were partially mediated by more proximal variables, whereas leader KSAs demonstrated a relatively strong, direct influence on performance. The 1 exception was that Conscientiousness,a hypothesized distal antecedent,had a notable direct effect on leader performance. The implications of these findings for leadership research and practice are discussed. [source]