Effect of Risk of Bias on the Effect Size of Meta-Analytic Estimates in Randomized Controlled Trials in Periodontology and Implant Dentistry.

PubMed

Faggion, Clovis Mariano; Wu, Yun-Chun; Scheidgen, Moritz; Tu, Yu-Kang

2015-01-01

Risk of bias (ROB) may threaten the internal validity of a clinical trial by distorting the magnitude of treatment effect estimates, although some conflicting information on this assumption exists. The objective of this study was evaluate the effect of ROB on the magnitude of treatment effect estimates in randomized controlled trials (RCTs) in periodontology and implant dentistry. A search for Cochrane systematic reviews (SRs), including meta-analyses of RCTs published in periodontology and implant dentistry fields, was performed in the Cochrane Library in September 2014. Random-effect meta-analyses were performed by grouping RCTs with different levels of ROBs in three domains (sequence generation, allocation concealment, and blinding of outcome assessment). To increase power and precision, only SRs with meta-analyses including at least 10 RCTs were included. Meta-regression was performed to investigate the association between ROB characteristics and the magnitudes of intervention effects in the meta-analyses. Of the 24 initially screened SRs, 21 SRs were excluded because they did not include at least 10 RCTs in the meta-analyses. Three SRs (two from periodontology field) generated information for conducting 27 meta-analyses. Meta-regression did not reveal significant differences in the relationship of the ROB level with the size of treatment effect estimates, although a trend for inflated estimates was observed in domains with unclear ROBs. In this sample of RCTs, high and (mainly) unclear risks of selection and detection biases did not seem to influence the size of treatment effect estimates, although several confounders might have influenced the strength of the association.

Standardized Regression Coefficients as Indices of Effect Sizes in Meta-Analysis

ERIC Educational Resources Information Center

Kim, Rae Seon

2011-01-01

When conducting a meta-analysis, it is common to find many collected studies that report regression analyses, because multiple regression analysis is widely used in many fields. Meta-analysis uses effect sizes drawn from individual studies as a means of synthesizing a collection of results. However, indices of effect size from regression analyses…

Class Size Effects on Reading Achievement Using PIRLS Data: Evidence from Greece

ERIC Educational Resources Information Center

Konstantopoulos, Spyros; Traynor, Anne

2014-01-01

Background/Context: The effects of class size on student achievement have gained considerable attention in education research and policy, especially over the last 30 years. Perhaps the best evidence about the effects of class size thus far has been produced from analyses of Project STAR data, a large-scale experiment where students and teachers…

β-alanine supplementation to improve exercise capacity and performance: a systematic review and meta-analysis.

PubMed

Saunders, Bryan; Elliott-Sale, Kirsty; Artioli, Guilherme G; Swinton, Paul A; Dolan, Eimear; Roschel, Hamilton; Sale, Craig; Gualano, Bruno

2017-04-01

To conduct a systematic review and meta-analysis of the evidence on the effects of β-alanine supplementation on exercise capacity and performance. This study was designed in accordance with PRISMA guidelines. A 3-level mixed effects model was employed to model effect sizes and account for dependencies within data. 3 databases (PubMed, Google Scholar, Web of Science) were searched using a number of terms ('β-alanine' and 'Beta-alanine' combined with 'supplementation', 'exercise', 'training', 'athlete', 'performance' and 'carnosine'). Inclusion/exclusion criteria limited articles to double-blinded, placebo-controlled studies investigating the effects of β-alanine supplementation on an exercise measure. All healthy participant populations were considered, while supplementation protocols were restricted to chronic ingestion. Cross-over designs were excluded due to the long washout period for skeletal muscle carnosine following supplementation. A single outcome measure was extracted for each exercise protocol and converted to effect sizes for meta-analyses. 40 individual studies employing 65 different exercise protocols and totalling 70 exercise measures in 1461 participants were included in the analyses. A significant overall effect size of 0.18 (95% CI 0.08 to 0.28) was shown. Meta-regression demonstrated that exercise duration significantly (p=0.004) moderated effect sizes. Subgroup analyses also identified the type of exercise as a significant (p=0.013) moderator of effect sizes within an exercise time frame of 0.5-10 min with greater effect sizes for exercise capacity (0.4998 (95% CI 0.246 to 0.753)) versus performance (0.1078 (95% CI -0.201 to 0.416)). There was no moderating effect of training status (p=0.559), intermittent or continuous exercise (p=0.436) or total amount of β-alanine ingested (p=0.438). Co-supplementation with sodium bicarbonate resulted in the largest effect size when compared with placebo (0.43 (95% CI 0.22 to 0.64)). β-alanine had a significant overall effect while subgroup analyses revealed a number of modifying factors. These data allow individuals to make informed decisions as to the likelihood of an ergogenic effect with β-alanine supplementation based on their chosen exercise modality. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Small sample sizes in the study of ontogenetic allometry; implications for palaeobiology

PubMed Central

Vavrek, Matthew J.

2015-01-01

Quantitative morphometric analyses, particularly ontogenetic allometry, are common methods used in quantifying shape, and changes therein, in both extinct and extant organisms. Due to incompleteness and the potential for restricted sample sizes in the fossil record, palaeobiological analyses of allometry may encounter higher rates of error. Differences in sample size between fossil and extant studies and any resulting effects on allometric analyses have not been thoroughly investigated, and a logical lower threshold to sample size is not clear. Here we show that studies based on fossil datasets have smaller sample sizes than those based on extant taxa. A similar pattern between vertebrates and invertebrates indicates this is not a problem unique to either group, but common to both. We investigate the relationship between sample size, ontogenetic allometric relationship and statistical power using an empirical dataset of skull measurements of modern Alligator mississippiensis. Across a variety of subsampling techniques, used to simulate different taphonomic and/or sampling effects, smaller sample sizes gave less reliable and more variable results, often with the result that allometric relationships will go undetected due to Type II error (failure to reject the null hypothesis). This may result in a false impression of fewer instances of positive/negative allometric growth in fossils compared to living organisms. These limitations are not restricted to fossil data and are equally applicable to allometric analyses of rare extant taxa. No mathematically derived minimum sample size for ontogenetic allometric studies is found; rather results of isometry (but not necessarily allometry) should not be viewed with confidence at small sample sizes. PMID:25780770

Ecstasy (MDMA) and memory function: a meta-analytic update.

PubMed

Laws, Keith R; Kokkalis, Joy

2007-08-01

A meta-analysis was conducted to examine the impact of recreational ecstasy use on short-term memory (STM), long-term memory (LTM), verbal and visual memory. We located 26 studies containing memory data for ecstasy and non-ecstasy users from which effect sizes could be derived. The analyses provided measures of STM and LTM in 610 and 439 ecstasy users and revealed moderate-to-large effect sizes (Cohen's d) of d = -0.63 and d = -0.87, respectively. The difference between STM versus LTM was non-significant. The effect size for verbal memory was large (d = -1.00) and significantly larger than the small effect size for visual memory (d = -0.27). Indeed, our analyses indicate that visual memory may be affected more by concurrent cannabis use. Finally, we found that the total lifetime number of ecstasy tablets consumed did not significantly predict memory performance. Copyright 2007 John Wiley & Sons, Ltd.

Effects of Aperture Size on Q factor and Shielding Effectiveness of a Cubic Resonator

NASA Astrophysics Data System (ADS)

Parr, Stefan; Chromy, Stephan; Dickmann, Stefan; Schaarschmidt, Martin

2017-09-01

The EMC properties of a cubic metallic shield are highly affected by its resonances. At the resonant frequencies, the shielding effectiveness (SE) collapses, which results in high field strengths inside the cavity. This can cause failure or even breakdown of electronic devices inside the shield. The resonant behaviour is mainly determined by the quality or Q factor of the shield. In this paper, the effects of the aperture size on the Q factor and the SE of an electrically large, cubic shield are analysed. At first, a method is developed in order to determine the Q factor based on the resonance behaviour of the shield in time domain. Only the first resonance of the shield is considered therefore. The results are evaluated for different aperture diameters and compared with theory for the Q factor. The dominant coupling mechanism of electromagnetic energy into the shield is thus identified. Then the effect of aperture size on the SE is analysed. The excitation of resonances is very probable if the interfering signal is an ultrawideband (UWB) pulse, which constitutes a typical intentional electromagnetic interference (IEMI) scenario. Therefore, the relation between aperture size and SE is analysed using the theory of the transient SE for a broadband signal with a constant spectral density distribution. The results show, that a worst case aperture size exists, where the SE has its minimum.

Effect of Risk of Bias on the Effect Size of Meta-Analytic Estimates in Randomized Controlled Trials in Periodontology and Implant Dentistry

PubMed Central

Faggion, Clovis Mariano; Wu, Yun-Chun; Scheidgen, Moritz; Tu, Yu-Kang

2015-01-01

Background Risk of bias (ROB) may threaten the internal validity of a clinical trial by distorting the magnitude of treatment effect estimates, although some conflicting information on this assumption exists. Objective The objective of this study was evaluate the effect of ROB on the magnitude of treatment effect estimates in randomized controlled trials (RCTs) in periodontology and implant dentistry. Methods A search for Cochrane systematic reviews (SRs), including meta-analyses of RCTs published in periodontology and implant dentistry fields, was performed in the Cochrane Library in September 2014. Random-effect meta-analyses were performed by grouping RCTs with different levels of ROBs in three domains (sequence generation, allocation concealment, and blinding of outcome assessment). To increase power and precision, only SRs with meta-analyses including at least 10 RCTs were included. Meta-regression was performed to investigate the association between ROB characteristics and the magnitudes of intervention effects in the meta-analyses. Results Of the 24 initially screened SRs, 21 SRs were excluded because they did not include at least 10 RCTs in the meta-analyses. Three SRs (two from periodontology field) generated information for conducting 27 meta-analyses. Meta-regression did not reveal significant differences in the relationship of the ROB level with the size of treatment effect estimates, although a trend for inflated estimates was observed in domains with unclear ROBs. Conclusion In this sample of RCTs, high and (mainly) unclear risks of selection and detection biases did not seem to influence the size of treatment effect estimates, although several confounders might have influenced the strength of the association. PMID:26422698

The Power of Low Back Pain Trials: A Systematic Review of Power, Sample Size, and Reporting of Sample Size Calculations Over Time, in Trials Published Between 1980 and 2012.

PubMed

Froud, Robert; Rajendran, Dévan; Patel, Shilpa; Bright, Philip; Bjørkli, Tom; Eldridge, Sandra; Buchbinder, Rachelle; Underwood, Martin

2017-06-01

A systematic review of nonspecific low back pain trials published between 1980 and 2012. To explore what proportion of trials have been powered to detect different bands of effect size; whether there is evidence that sample size in low back pain trials has been increasing; what proportion of trial reports include a sample size calculation; and whether likelihood of reporting sample size calculations has increased. Clinical trials should have a sample size sufficient to detect a minimally important difference for a given power and type I error rate. An underpowered trial is one within which probability of type II error is too high. Meta-analyses do not mitigate underpowered trials. Reviewers independently abstracted data on sample size at point of analysis, whether a sample size calculation was reported, and year of publication. Descriptive analyses were used to explore ability to detect effect sizes, and regression analyses to explore the relationship between sample size, or reporting sample size calculations, and time. We included 383 trials. One-third were powered to detect a standardized mean difference of less than 0.5, and 5% were powered to detect less than 0.3. The average sample size was 153 people, which increased only slightly (∼4 people/yr) from 1980 to 2000, and declined slightly (∼4.5 people/yr) from 2005 to 2011 (P < 0.00005). Sample size calculations were reported in 41% of trials. The odds of reporting a sample size calculation (compared to not reporting one) increased until 2005 and then declined (Equation is included in full-text article.). Sample sizes in back pain trials and the reporting of sample size calculations may need to be increased. It may be justifiable to power a trial to detect only large effects in the case of novel interventions. 3.

Assessing the effect of elevated carbon dioxide on soil carbon: a comparison of four meta-analyses.

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

Hungate, B. A.; van Groenigen, K.; Six, J.

2009-08-01

Soil is the largest reservoir of organic carbon (C) in the terrestrial biosphere and soil C has a relatively long mean residence time. Rising atmospheric carbon dioxide (CO{sub 2}) concentrations generally increase plant growth and C input to soil, suggesting that soil might help mitigate atmospheric CO{sub 2} rise and global warming. But to what extent mitigation will occur is unclear. The large size of the soil C pool not only makes it a potential buffer against rising atmospheric CO{sub 2}, but also makes it difficult to measure changes amid the existing background. Meta-analysis is one tool that can overcomemore » the limited power of single studies. Four recent meta-analyses addressed this issue but reached somewhat different conclusions about the effect of elevated CO{sub 2} on soil C accumulation, especially regarding the role of nitrogen (N) inputs. Here, we assess the extent of differences between these conclusions and propose a new analysis of the data. The four meta-analyses included different studies, derived different effect size estimates from common studies, used different weighting functions and metrics of effect size, and used different approaches to address nonindependence of effect sizes. Although all factors influenced the mean effect size estimates and subsequent inferences, the approach to independence had the largest influence. We recommend that meta-analysts critically assess and report choices about effect size metrics and weighting functions, and criteria for study selection and independence. Such decisions need to be justified carefully because they affect the basis for inference. Our new analysis, with a combined data set, confirms that the effect of elevated CO{sub 2} on net soil C accumulation increases with the addition of N fertilizers. Although the effect at low N inputs was not significant, statistical power to detect biogeochemically important effect sizes at low N is limited, even with meta-analysis, suggesting the continued need for long-term experiments.« less

Publication Bias in Special Education Meta-Analyses

ERIC Educational Resources Information Center

Gage, Nicholas A.; Cook, Bryan G.; Reichow, Brian

2017-01-01

Publication bias involves the disproportionate representation of studies with large and significant effects in the published research. Among other problems, publication bias results in inflated omnibus effect sizes in meta-analyses, giving the impression that interventions have stronger effects than they actually do. Although evidence suggests…

Analyses of scattering characteristics of chosen anthropogenic aerosols

NASA Astrophysics Data System (ADS)

Kaszczuk, Miroslawa; Mierczyk, Zygmunt; Muzal, Michal

2008-10-01

In the work, analyses of scattering profile of chosen anthropogenic aerosols for two wavelengths (λ1 = 1064 nm and λ2 = 532 nm) were made. As an example of anthropogenic aerosol three different pyrotechnic mixtures (DM11, M2, M16) were taken. Main parameters of smoke particles were firstly analyzed and well described, taking particle shape and size into special consideration. Shape of particles was analyzed on the basis of SEM pictures, and particle size was measured. Participation of particles in each fixed fraction characterized by range of sizes was analyzed and parameters of smoke particles of characteristic sizes and function describing aerosol size distribution (ASD) were determinated. Analyses of scattering profiles were carried out on the basis of both model of scattering on spherical and nonspherical particles. In the case of spherical particles Rayleigh-Mie model was used and for nonspherical particles analyses firstly model of spheroids was used, and then Rayleigh-Mie one. For each characteristic particle one calculated value of four parameters (effective scattering cross section σSCA, effective backscattering cross section σBSCA, scattering efficiency QSCA, backscattering efficiency QBSCA) and value of backscattering coefficient β for whole particles population. Obtained results were compared with the same parameters calculated for natural aerosol (cirrus cloud).

Orphan therapies: making best use of postmarket data.

PubMed

Maro, Judith C; Brown, Jeffrey S; Dal Pan, Gerald J; Li, Lingling

2014-08-01

Postmarket surveillance of the comparative safety and efficacy of orphan therapeutics is challenging, particularly when multiple therapeutics are licensed for the same orphan indication. To make best use of product-specific registry data collected to fulfill regulatory requirements, we propose the creation of a distributed electronic health data network among registries. Such a network could support sequential statistical analyses designed to detect early warnings of excess risks. We use a simulated example to explore the circumstances under which a distributed network may prove advantageous. We perform sample size calculations for sequential and non-sequential statistical studies aimed at comparing the incidence of hepatotoxicity following initiation of two newly licensed therapies for homozygous familial hypercholesterolemia. We calculate the sample size savings ratio, or the proportion of sample size saved if one conducted a sequential study as compared to a non-sequential study. Then, using models to describe the adoption and utilization of these therapies, we simulate when these sample sizes are attainable in calendar years. We then calculate the analytic calendar time savings ratio, analogous to the sample size savings ratio. We repeat these analyses for numerous scenarios. Sequential analyses detect effect sizes earlier or at the same time as non-sequential analyses. The most substantial potential savings occur when the market share is more imbalanced (i.e., 90% for therapy A) and the effect size is closest to the null hypothesis. However, due to low exposure prevalence, these savings are difficult to realize within the 30-year time frame of this simulation for scenarios in which the outcome of interest occurs at or more frequently than one event/100 person-years. We illustrate a process to assess whether sequential statistical analyses of registry data performed via distributed networks may prove a worthwhile infrastructure investment for pharmacovigilance.

A d-statistic for single-case designs that is equivalent to the usual between-groups d-statistic.

PubMed

Shadish, William R; Hedges, Larry V; Pustejovsky, James E; Boyajian, Jonathan G; Sullivan, Kristynn J; Andrade, Alma; Barrientos, Jeannette L

2014-01-01

We describe a standardised mean difference statistic (d) for single-case designs that is equivalent to the usual d in between-groups experiments. We show how it can be used to summarise treatment effects over cases within a study, to do power analyses in planning new studies and grant proposals, and to meta-analyse effects across studies of the same question. We discuss limitations of this d-statistic, and possible remedies to them. Even so, this d-statistic is better founded statistically than other effect size measures for single-case design, and unlike many general linear model approaches such as multilevel modelling or generalised additive models, it produces a standardised effect size that can be integrated over studies with different outcome measures. SPSS macros for both effect size computation and power analysis are available.

Class Size Reduction or Rapid Formative Assessment?: A Comparison of Cost-Effectiveness

ERIC Educational Resources Information Center

Yeh, Stuart S.

2009-01-01

The cost-effectiveness of class size reduction (CSR) was compared with the cost-effectiveness of rapid formative assessment, a promising alternative for raising student achievement. Drawing upon existing meta-analyses of the effects of student-teacher ratio, evaluations of CSR in Tennessee, California, and Wisconsin, and RAND cost estimates, CSR…

Non-invasive brain stimulation to investigate language production in healthy speakers: A meta-analysis.

PubMed

Klaus, Jana; Schutter, Dennis J L G

2018-06-01

Non-invasive brain stimulation (NIBS) has become a common method to study the interrelations between the brain and language functioning. This meta-analysis examined the efficacy of transcranial magnetic stimulation (TMS) and direct current stimulation (tDCS) in the study of language production in healthy volunteers. Forty-five effect sizes from 30 studies which investigated the effects of NIBS on picture naming or verbal fluency in healthy participants were meta-analysed. Further sub-analyses investigated potential influences of stimulation type, control, target site, task, online vs. offline application, and current density of the target electrode. Random effects modelling showed a small, but reliable effect of NIBS on language production. Subsequent analyses indicated larger weighted mean effect sizes for TMS as compared to tDCS studies. No statistical differences for the other sub-analyses were observed. We conclude that NIBS is a useful method for neuroscientific studies on language production in healthy volunteers. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Interventions to Improve Medication Adherence in Hypertensive Patients: Systematic Review and Meta-analysis.

PubMed

Conn, Vicki S; Ruppar, Todd M; Chase, Jo-Ana D; Enriquez, Maithe; Cooper, Pamela S

2015-12-01

This systematic review applied meta-analytic procedures to synthesize medication adherence interventions that focus on adults with hypertension. Comprehensive searching located trials with medication adherence behavior outcomes. Study sample, design, intervention characteristics, and outcomes were coded. Random-effects models were used in calculating standardized mean difference effect sizes. Moderator analyses were conducted using meta-analytic analogues of ANOVA and regression to explore associations between effect sizes and sample, design, and intervention characteristics. Effect sizes were calculated for 112 eligible treatment-vs.-control group outcome comparisons of 34,272 subjects. The overall standardized mean difference effect size between treatment and control subjects was 0.300. Exploratory moderator analyses revealed interventions were most effective among female, older, and moderate- or high-income participants. The most promising intervention components were those linking adherence behavior with habits, giving adherence feedback to patients, self-monitoring of blood pressure, using pill boxes and other special packaging, and motivational interviewing. The most effective interventions employed multiple components and were delivered over many days. Future research should strive for minimizing risks of bias common in this literature, especially avoiding self-report adherence measures.

The impact of sample size on the reproducibility of voxel-based lesion-deficit mappings.

PubMed

Lorca-Puls, Diego L; Gajardo-Vidal, Andrea; White, Jitrachote; Seghier, Mohamed L; Leff, Alexander P; Green, David W; Crinion, Jenny T; Ludersdorfer, Philipp; Hope, Thomas M H; Bowman, Howard; Price, Cathy J

2018-07-01

This study investigated how sample size affects the reproducibility of findings from univariate voxel-based lesion-deficit analyses (e.g., voxel-based lesion-symptom mapping and voxel-based morphometry). Our effect of interest was the strength of the mapping between brain damage and speech articulation difficulties, as measured in terms of the proportion of variance explained. First, we identified a region of interest by searching on a voxel-by-voxel basis for brain areas where greater lesion load was associated with poorer speech articulation using a large sample of 360 right-handed English-speaking stroke survivors. We then randomly drew thousands of bootstrap samples from this data set that included either 30, 60, 90, 120, 180, or 360 patients. For each resample, we recorded effect size estimates and p values after conducting exactly the same lesion-deficit analysis within the previously identified region of interest and holding all procedures constant. The results show (1) how often small effect sizes in a heterogeneous population fail to be detected; (2) how effect size and its statistical significance varies with sample size; (3) how low-powered studies (due to small sample sizes) can greatly over-estimate as well as under-estimate effect sizes; and (4) how large sample sizes (N ≥ 90) can yield highly significant p values even when effect sizes are so small that they become trivial in practical terms. The implications of these findings for interpreting the results from univariate voxel-based lesion-deficit analyses are discussed. Copyright © 2018 The Author(s). Published by Elsevier Ltd.. All rights reserved.

The albatross plot: A novel graphical tool for presenting results of diversely reported studies in a systematic review

PubMed Central

Jones, Hayley E.; Martin, Richard M.; Lewis, Sarah J.; Higgins, Julian P.T.

2017-01-01

Abstract Meta‐analyses combine the results of multiple studies of a common question. Approaches based on effect size estimates from each study are generally regarded as the most informative. However, these methods can only be used if comparable effect sizes can be computed from each study, and this may not be the case due to variation in how the studies were done or limitations in how their results were reported. Other methods, such as vote counting, are then used to summarize the results of these studies, but most of these methods are limited in that they do not provide any indication of the magnitude of effect. We propose a novel plot, the albatross plot, which requires only a 1‐sided P value and a total sample size from each study (or equivalently a 2‐sided P value, direction of effect and total sample size). The plot allows an approximate examination of underlying effect sizes and the potential to identify sources of heterogeneity across studies. This is achieved by drawing contours showing the range of effect sizes that might lead to each P value for given sample sizes, under simple study designs. We provide examples of albatross plots using data from previous meta‐analyses, allowing for comparison of results, and an example from when a meta‐analysis was not possible. PMID:28453179

Size, Book-to-Market Ratio and Relativity of Accounting Information Value: Empirical Research on the Chinese Listed Company

NASA Astrophysics Data System (ADS)

Yu, Jing; Cheng, Siwei; Xu, Bin

Recently there are many literatures studying the effect of factors such as size or book-market ratio on fluctuation of accounting earnings, stock price or earnings respectively, but so far their affection on accounting information value relativity has been scarcely addressed. This paper presents the detail analyses of their effect of the two factors to the relativity of accounting information value respectively by taking Shanghai and Shenzhen stock markets as sample. And the analyses supports the following two hypotheses, (1) The relativity of accounting information value of big size corporation is more than that of small size corporation. (2) The relativity of accounting information value of low B/M ratio corporation is more than that of low B/M ratio corporation.

Theoretical and experimental analyses to determine the effects of crystal orientation and grain size on the thermoelectric properties of oblique deposited bismuth telluride thin films

NASA Astrophysics Data System (ADS)

Morikawa, Satoshi; Satake, Yuji; Takashiri, Masayuki

2018-06-01

The effects of crystal orientation and grain size on the thermoelectric properties of Bi2Te3 thin films were investigated by conducting experimental and theoretical analyses. To vary the crystal orientation and grain size, we performed oblique deposition, followed by thermal annealing treatment. The crystal orientation decreased as the oblique angle was increased, while the grain size was not changed significantly. The thermoelectric properties were measured at room temperature. A theoretical analysis was performed using a first principles method based on density functional theory. Then the semi-classical Boltzmann transport equation was used in the relaxation time approximation, with the effect of grain size included. Furthermore, the effect of crystal orientation was included in the calculation based on a simple semi-experimental model. A maximum power factor of 11.6 µW/(cm·K2) was obtained at an oblique angle of 40°. The calculated thermoelectric properties were in very good agreement with the experimentally measured values.

Scale-dependent effect sizes of ecological drivers on biodiversity: why standardised sampling is not enough.

PubMed

Chase, Jonathan M; Knight, Tiffany M

2013-05-01

There is little consensus about how natural (e.g. productivity, disturbance) and anthropogenic (e.g. invasive species, habitat destruction) ecological drivers influence biodiversity. Here, we show that when sampling is standardised by area (species density) or individuals (rarefied species richness), the measured effect sizes depend critically on the spatial grain and extent of sampling, as well as the size of the species pool. This compromises comparisons of effects sizes within studies using standard statistics, as well as among studies using meta-analysis. To derive an unambiguous effect size, we advocate that comparisons need to be made on a scale-independent metric, such as Hurlbert's Probability of Interspecific Encounter. Analyses of this metric can be used to disentangle the relative influence of changes in the absolute and relative abundances of individuals, as well as their intraspecific aggregations, in driving differences in biodiversity among communities. This and related approaches are necessary to achieve generality in understanding how biodiversity responds to ecological drivers and will necessitate a change in the way many ecologists collect and analyse their data. © 2013 John Wiley & Sons Ltd/CNRS.

Media effects of experimental presentation of the ideal physique on eating disorder symptoms: a meta-analysis of laboratory studies.

PubMed

Hausenblas, Heather A; Campbell, Anna; Menzel, Jessie E; Doughty, Jessica; Levine, Michael; Thompson, J Kevin

2013-02-01

Older meta-analyses of the effects of the media's portrayal of the ideal physique have found small effects revealing that exposure to the ideal physique increases body image concerns. These meta-analyses also included correlational, quasi-experimental, and experimental studies, with limited examination of moderators and other relevant outcomes besides body image. We conducted a systematic literature search and identified 33 experimental (i.e., pre and post data for both experimental and control groups) laboratory studies examining the effects of acute exposure to the media's portrayal of the ideal physique on eating disorder symptoms (i.e., body image, positive affect, negative affect, self-esteem, anger, anxiety and depression) and the mechanisms that moderate this effect. Fourteen separate meta-analyses revealed a range of small to moderate effect sizes for change in outcomes from pre to post for both experimental and control groups. Exposure to images of the ideal physique resulted in small effect sizes for increased depression and anger and decreased self-esteem and positive affect. Moderator analyses revealed moderate effect sizes for increased depression and body dissatisfaction among high-risk participants. This meta-analysis makes it clear that media exposure of the ideal physique results in small changes in eating disorder symptoms, particularly with participants at high risk for developing an eating disorder. Further research is needed to examine the longitudinal effects of media exposure of eating disorder symptoms. Copyright © 2012 Elsevier Ltd. All rights reserved.

The effectiveness of booster sessions in CBT treatment for child and adolescent mood and anxiety disorders.

PubMed

Gearing, Robin E; Schwalbe, Craig S J; Lee, RaeHyuck; Hoagwood, Kimberly E

2013-09-01

To investigate the effects of booster sessions in cognitive behavioral therapy (CBT) for children and adolescents with mood or anxiety disorders, whereas controlling for youth demographics (e.g., gender, age), primary diagnosis, and intervention characteristics (e.g., treatment modality, number of sessions). Electronic databases were searched for CBT interventions for youth with mood and anxiety disorders. Fifty-three (k = 53) studies investigating 1,937 youth met criteria for inclusion. Booster sessions were examined using two case-controlled effect sizes: pre-post and pre-follow-up (6 months) effect sizes and employing weighted least squares (WLSs) regressions. Meta-analyses found pre-post studies with booster sessions had a larger effect size r = .58 (k = 15; 95% CI = 0.52-0.65; P < .01) than those without booster sessions r = .45 (k = 38; 95% CI = 0.41-0.49; P < .001). In the WLS regression analyses, controlling for demographic factors, primary diagnosis, and intervention characteristics, studies with booster sessions showed larger pre-post effect sizes than those without booster sessions (B = 0.13, P < .10). Similarly, pre-follow-up studies with booster sessions showed a larger effect size r = .64 (k = 10; 95% CI = 0.57-0.70; P < .10) than those without booster sessions r = .48 (k = 20; 95% CI = 0.42-0.53; P < .01). Also, in the WLS regression analyses, pre-follow-up studies showed larger effect sizes than those without booster sessions (B = 0.08, P < .01) after accounting for all control variables. Result suggests that CBT interventions with booster sessions are more effective and the effect is more sustainable for youth managing mood or anxiety disorders than CBT interventions without booster sessions. © 2013 Wiley Periodicals, Inc.

The Relationship of Class Size Effects and Teacher Salary

ERIC Educational Resources Information Center

Peevely, Gary; Hedges, Larry; Nye, Barbara A.

2005-01-01

The effects of class size on academic achievement have been studied for decades. Although the results of small-scale, randomized experiments and large-scale, econometric studies point to positive effects of small classes, some scholars see the evidence as ambiguous. Recent analyses from a 4-year, large-scale, randomized experiment on the effects…

Effect Size in Clinical Phonology

ERIC Educational Resources Information Center

Gierut, Judith A.; Morrisette, Michele L.

2011-01-01

The purpose of this article is to motivate the use of effect size (ES) for single-subject research in clinical phonology, with an eye towards meta-analyses of treatment effects for children with phonological disorders. Standard mean difference (SMD) is introduced and illustrated as one ES well suited to the multiple baseline (MBL) design and…

The Effect of Size Fraction in Analyses of Benthic Foraminifera Assemblages: A Case Study Comparing Assemblages from the >125 μm and >150 μm Size Fractions

NASA Astrophysics Data System (ADS)

Weinkauf, Manuel F. G.; Milker, Yvonne

2018-05-01

Benthic Foraminifera assemblages are employed for past environmental reconstructions, as well as for biomonitoring studies in recent environments. Despite their established status for such applications, and existing protocols for sample treatment, not all studies using benthic Foraminifera employ the same methodology. For instance, there is no broad practical consensus whether to use the >125 µm or >150 µm size fraction for benthic foraminiferal assemblage analyses. Here, we use early Pleistocene material from the Pefka E section on the Island of Rhodes (Greece), which has been counted in both size fractions, to investigate whether a 25 µm difference in the counted fraction is already sufficient to have an impact on ecological studies. We analysed the influence of the difference in size fraction on studies of biodiversity as well as multivariate assemblage analyses of the sample material. We found that for both types of studies, the general trends remain the same regardless of the chosen size fraction, but in detail significant differences emerge which are not consistently distributed between samples. Studies which require a high degree of precision can thus not compare results from analyses that used different size fractions, and the inconsistent distribution of differences makes it impossible to develop corrections for this issue. We therefore advocate the consistent use of the >125 µm size fraction for benthic foraminiferal studies in the future.

Class Size.

ERIC Educational Resources Information Center

Ellis, Thomas I.

1985-01-01

After a brief introduction identifying current issues and trends in research on class size, this brochure reviews five recent studies bearing on the relationship of class size to educational effectiveness. Part 1 is a review of two interrelated and highly controversial "meta-analyses" or statistical integrations of research findings on…

Stepping Stones Triple P-Positive Parenting Program for children with disability: a systematic review and meta-analysis.

PubMed

Tellegen, Cassandra L; Sanders, Matthew R

2013-05-01

This systematic review and meta-analysis evaluated the treatment effects of a behavioral family intervention, Stepping Stones Triple P (SSTP) for parents of children with disabilities. SSTP is a system of five intervention levels of increasing intensity and narrowing population reach. Twelve studies, including a total of 659 families, met eligibility criteria. Studies needed to have evaluated SSTP, be written in English or German, contribute original data, and have sufficient data for analyses. No restrictions were placed on study design. A series of meta-analyses were performed for seven different outcome categories. Analyses were conducted on the combination of all four levels of SSTP for which evidence exists (Levels 2-5), and were also conducted separately for each level of SSTP. Significant moderate effect sizes were found for all levels of SSTP for reducing child problems, the primary outcome of interest. On secondary outcomes, significant overall effect sizes were found for parenting styles, parenting satisfaction and efficacy, parental adjustment, parental relationship, and observed child behaviors. No significant treatment effects were found for observed parenting behaviors. Moderator analyses showed no significant differences in effect sizes across the levels of SSTP intervention, with the exception of child observations. Risk of bias within and across studies was assessed. Analyses suggested that publication bias and selective reporting bias were not likely to have heavily influenced the findings. The overall evidence base supported the effectiveness of SSTP as an intervention for improving child and parent outcomes in families of children with disabilities. Limitations and future research directions are discussed. Copyright © 2013 Elsevier Ltd. All rights reserved.

"Narrowing the transmission gap: A synthesis of three decades of research on intergenerational transmission of attachment": Correction.

PubMed

2018-04-01

Reports an error in "Narrowing the transmission gap: A synthesis of three decades of research on intergenerational transmission of attachment" by Marije L. Verhage, Carlo Schuengel, Sheri Madigan, R. M. Pasco Fearon, Mirjam Oosterman, Rosalinda Cassibba, Marian J. Bakermans-Kranenburg and Marinus H. van IJzendoorn ( Psychological Bulletin , 2016[Apr], Vol 142[4], 337-366). In the article, there are errors in Table 7. The percentages of the attachment classifications do not add up to 100%. The corrected version of Table 7 is provided in the erratum. (The following abstract of the original article appeared in record 2015-55801-001.) Twenty years ago, meta-analytic results (k = 19) confirmed the association between caregiver attachment representations and child-caregiver attachment (Van IJzendoorn, 1995). A test of caregiver sensitivity as the mechanism behind this intergenerational transmission showed an intriguing "transmission gap." Since then, the intergenerational transmission of attachment and the transmission gap have been studied extensively, and now extend to diverse populations from all over the globe. Two decades later, the current review revisited the effect sizes of intergenerational transmission, the heterogeneity of the transmission effects, and the size of the transmission gap. Analyses were carried out with a total of 95 samples (total N = 4,819). All analyses confirmed intergenerational transmission of attachment, with larger effect sizes for secure-autonomous transmission (r = .31) than for unresolved transmission (r = .21), albeit with significantly smaller effect sizes than 2 decades earlier (r = .47 and r = .31, respectively). Effect sizes were moderated by risk status of the sample, biological relatedness of child-caregiver dyads, and age of the children. Multivariate moderator analyses showed that unpublished and more recent studies had smaller effect sizes than published and older studies. Path analyses showed that the transmission could not be fully explained by caregiver sensitivity, with more recent studies narrowing but not bridging the "transmission gap." Implications for attachment theory as well as future directions for research are discussed. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Meta-Analysis of Effect Sizes Reported at Multiple Time Points Using General Linear Mixed Model.

PubMed

Musekiwa, Alfred; Manda, Samuel O M; Mwambi, Henry G; Chen, Ding-Geng

2016-01-01

Meta-analysis of longitudinal studies combines effect sizes measured at pre-determined time points. The most common approach involves performing separate univariate meta-analyses at individual time points. This simplistic approach ignores dependence between longitudinal effect sizes, which might result in less precise parameter estimates. In this paper, we show how to conduct a meta-analysis of longitudinal effect sizes where we contrast different covariance structures for dependence between effect sizes, both within and between studies. We propose new combinations of covariance structures for the dependence between effect size and utilize a practical example involving meta-analysis of 17 trials comparing postoperative treatments for a type of cancer, where survival is measured at 6, 12, 18 and 24 months post randomization. Although the results from this particular data set show the benefit of accounting for within-study serial correlation between effect sizes, simulations are required to confirm these results.

Size scale effect in cavitation erosion

NASA Technical Reports Server (NTRS)

Rao, P. V.; Rao, B. C.; Buckley, D. H.

1982-01-01

An overview and data analyses pertaining to cavitation erosion size scale effects are presented. The exponents n in the power law relationship are found to vary from 1.7 to 4.9 for venturi and rotating disk devices supporting the values reported in the literature. Suggestions for future studies were made to arrive at further true scale effects.

The albatross plot: A novel graphical tool for presenting results of diversely reported studies in a systematic review.

PubMed

Harrison, Sean; Jones, Hayley E; Martin, Richard M; Lewis, Sarah J; Higgins, Julian P T

2017-09-01

Meta-analyses combine the results of multiple studies of a common question. Approaches based on effect size estimates from each study are generally regarded as the most informative. However, these methods can only be used if comparable effect sizes can be computed from each study, and this may not be the case due to variation in how the studies were done or limitations in how their results were reported. Other methods, such as vote counting, are then used to summarize the results of these studies, but most of these methods are limited in that they do not provide any indication of the magnitude of effect. We propose a novel plot, the albatross plot, which requires only a 1-sided P value and a total sample size from each study (or equivalently a 2-sided P value, direction of effect and total sample size). The plot allows an approximate examination of underlying effect sizes and the potential to identify sources of heterogeneity across studies. This is achieved by drawing contours showing the range of effect sizes that might lead to each P value for given sample sizes, under simple study designs. We provide examples of albatross plots using data from previous meta-analyses, allowing for comparison of results, and an example from when a meta-analysis was not possible. Copyright © 2017 The Authors. Research Synthesis Methods Published by John Wiley & Sons Ltd.

The Number of Patients and Events Required to Limit the Risk of Overestimation of Intervention Effects in Meta-Analysis—A Simulation Study

PubMed Central

Thorlund, Kristian; Imberger, Georgina; Walsh, Michael; Chu, Rong; Gluud, Christian; Wetterslev, Jørn; Guyatt, Gordon; Devereaux, Philip J.; Thabane, Lehana

2011-01-01

Background Meta-analyses including a limited number of patients and events are prone to yield overestimated intervention effect estimates. While many assume bias is the cause of overestimation, theoretical considerations suggest that random error may be an equal or more frequent cause. The independent impact of random error on meta-analyzed intervention effects has not previously been explored. It has been suggested that surpassing the optimal information size (i.e., the required meta-analysis sample size) provides sufficient protection against overestimation due to random error, but this claim has not yet been validated. Methods We simulated a comprehensive array of meta-analysis scenarios where no intervention effect existed (i.e., relative risk reduction (RRR) = 0%) or where a small but possibly unimportant effect existed (RRR = 10%). We constructed different scenarios by varying the control group risk, the degree of heterogeneity, and the distribution of trial sample sizes. For each scenario, we calculated the probability of observing overestimates of RRR>20% and RRR>30% for each cumulative 500 patients and 50 events. We calculated the cumulative number of patients and events required to reduce the probability of overestimation of intervention effect to 10%, 5%, and 1%. We calculated the optimal information size for each of the simulated scenarios and explored whether meta-analyses that surpassed their optimal information size had sufficient protection against overestimation of intervention effects due to random error. Results The risk of overestimation of intervention effects was usually high when the number of patients and events was small and this risk decreased exponentially over time as the number of patients and events increased. The number of patients and events required to limit the risk of overestimation depended considerably on the underlying simulation settings. Surpassing the optimal information size generally provided sufficient protection against overestimation. Conclusions Random errors are a frequent cause of overestimation of intervention effects in meta-analyses. Surpassing the optimal information size will provide sufficient protection against overestimation. PMID:22028777

[A Review on the Use of Effect Size in Nursing Research].

PubMed

Kang, Hyuncheol; Yeon, Kyupil; Han, Sang Tae

2015-10-01

The purpose of this study was to introduce the main concepts of statistical testing and effect size and to provide researchers in nursing science with guidance on how to calculate the effect size for the statistical analysis methods mainly used in nursing. For t-test, analysis of variance, correlation analysis, regression analysis which are used frequently in nursing research, the generally accepted definitions of the effect size were explained. Some formulae for calculating the effect size are described with several examples in nursing research. Furthermore, the authors present the required minimum sample size for each example utilizing G*Power 3 software that is the most widely used program for calculating sample size. It is noted that statistical significance testing and effect size measurement serve different purposes, and the reliance on only one side may be misleading. Some practical guidelines are recommended for combining statistical significance testing and effect size measure in order to make more balanced decisions in quantitative analyses.

Grey literature in meta-analyses.

PubMed

Conn, Vicki S; Valentine, Jeffrey C; Cooper, Harris M; Rantz, Marilyn J

2003-01-01

In meta-analysis, researchers combine the results of individual studies to arrive at cumulative conclusions. Meta-analysts sometimes include "grey literature" in their evidential base, which includes unpublished studies and studies published outside widely available journals. Because grey literature is a source of data that might not employ peer review, critics have questioned the validity of its data and the results of meta-analyses that include it. To examine evidence regarding whether grey literature should be included in meta-analyses and strategies to manage grey literature in quantitative synthesis. This article reviews evidence on whether the results of studies published in peer-reviewed journals are representative of results from broader samplings of research on a topic as a rationale for inclusion of grey literature. Strategies to enhance access to grey literature are addressed. The most consistent and robust difference between published and grey literature is that published research is more likely to contain results that are statistically significant. Effect size estimates of published research are about one-third larger than those of unpublished studies. Unfunded and small sample studies are less likely to be published. Yet, importantly, methodological rigor does not differ between published and grey literature. Meta-analyses that exclude grey literature likely (a) over-represent studies with statistically significant findings, (b) inflate effect size estimates, and (c) provide less precise effect size estimates than meta-analyses including grey literature. Meta-analyses should include grey literature to fully reflect the existing evidential base and should assess the impact of methodological variations through moderator analysis.

Effects of prefrontal tDCS on executive function: Methodological considerations revealed by meta-analysis.

PubMed

Imburgio, Michael J; Orr, Joseph M

2018-05-01

A meta-analysis of studies using single-session transcranial direct current stimulation (tDCS) to target the dorsolateral prefrontal cortex (DLPFC) was undertaken to examine the effect of stimulation on executive function (EF) in healthy samples. 27 studies were included in analyses, yielding 71 effect sizes. The most relevant measure for each task was determined a priori and used to calculate Hedge's g. Methodological characteristics of each study were examined individually as potential moderators of effect size. Stimulation effects on three domains of EF (inhibition of prepotent responses, mental set shifting, and information updating and monitoring) were analyzed separately. In line with previous work, the current study found no significant effect of anodal unilateral tDCS, cathodal unilateral tDCS, or bilateral tDCS on EF. Further moderator and subgroup analyses were only carried out for anodal unilateral montages due to the small number of studies using other montages. Subgroup analyses revealed a significant effect of anodal unilateral tDCS on updating tasks, but not on inhibition or set-shifting tasks. Cathode location significantly moderated the effect of anodal unilateral tDCS. Extracranial cathodes yielded a significant effect on EF while cranial cathodes yielded no effect. Anode size also significantly moderated effect of anodal unilateral tDCS, with smaller anodes being more effective than larger anodes. In summary, anodal DLPFC stimulation is more effective at improving updating ability than inhibition and set-shifting ability, but anodal stimulation can significantly improve general executive function when extracranial cathodes or small anodes are used. Future meta-analyses may examine how stimulation's effects on specific behavioral tasks, rather than broader domains, might be affected by methodological moderators. Copyright © 2018 Elsevier Ltd. All rights reserved.

Structural effect of size on interracial friendship

PubMed Central

Cheng, Siwei; Xie, Yu

2013-01-01

Social contexts exert structural effects on individuals’ social relationships, including interracial friendships. In this study, we posit that, net of group composition, total context size has a distinct effect on interracial friendship. Under the assumptions of (i) maximization of preference in choosing a friend, (ii) multidimensionality of preference, and (iii) preference for same-race friends, we conducted analyses using microsimulation that yielded three main findings. First, increased context size decreases the likelihood of forming an interracial friendship. Second, the size effect increases with the number of preference dimensions. Third, the size effect is diluted by noise, i.e., the random component affecting friendship formation. Analysis of actual friendship data among 4,745 American high school students yielded results consistent with the main conclusion that increased context size promotes racial segregation and discourages interracial friendship. PMID:23589848

Appearance-related teasing, body dissatisfaction, and disordered eating: A meta-analysis.

PubMed

Menzel, Jessie E; Schaefer, Lauren M; Burke, Natasha L; Mayhew, Laura L; Brannick, Michael T; Thompson, J Kevin

2010-09-01

A meta-analysis was conducted to determine the relationship between appearance and weight-based teasing and three outcome measures: body dissatisfaction, restrictive eating, and bulimic behaviors. Four meta-analyses were conducted. Fifty effect sizes (N=10,618) resulted in a moderate effect size of .39 for the relationship between weight teasing and body dissatisfaction; 24 effect sizes (N=7190) resulted in an effect size of .32 for the relationship between appearance teasing and body dissatisfaction; 20 effect sizes (N=4792) resulted in an effect size of .35 for the relationship between weight teasing and dietary restraint; and 22 effect sizes (N=5091) resulted in an effect size of .36 for the relationship between weight teasing and bulimic behaviors. Significant moderators that emerged were teasing measure type, publication type, study type, age group, and gender. The findings offer further support for the inclusion of strategies in body image and eating disorders' prevention and intervention programs that focus on handling negative, appearance-related commentary. Copyright © 2010 Elsevier Ltd. All rights reserved.

Comparative analyses of basal rate of metabolism in mammals: data selection does matter.

PubMed

Genoud, Michel; Isler, Karin; Martin, Robert D

2018-02-01

Basal rate of metabolism (BMR) is a physiological parameter that should be measured under strictly defined experimental conditions. In comparative analyses among mammals BMR is widely used as an index of the intensity of the metabolic machinery or as a proxy for energy expenditure. Many databases with BMR values for mammals are available, but the criteria used to select metabolic data as BMR estimates have often varied and the potential effect of this variability has rarely been questioned. We provide a new, expanded BMR database reflecting compliance with standard criteria (resting, postabsorptive state; thermal neutrality; adult, non-reproductive status for females) and examine potential effects of differential selectivity on the results of comparative analyses. The database includes 1739 different entries for 817 species of mammals, compiled from the original sources. It provides information permitting assessment of the validity of each estimate and presents the value closest to a proper BMR for each entry. Using different selection criteria, several alternative data sets were extracted and used in comparative analyses of (i) the scaling of BMR to body mass and (ii) the relationship between brain mass and BMR. It was expected that results would be especially dependent on selection criteria with small sample sizes and with relatively weak relationships. Phylogenetically informed regression (phylogenetic generalized least squares, PGLS) was applied to the alternative data sets for several different clades (Mammalia, Eutheria, Metatheria, or individual orders). For Mammalia, a 'subsampling procedure' was also applied, in which random subsamples of different sample sizes were taken from each original data set and successively analysed. In each case, two data sets with identical sample size and species, but comprising BMR data with different degrees of reliability, were compared. Selection criteria had minor effects on scaling equations computed for large clades (Mammalia, Eutheria, Metatheria), although less-reliable estimates of BMR were generally about 12-20% larger than more-reliable ones. Larger effects were found with more-limited clades, such as sciuromorph rodents. For the relationship between BMR and brain mass the results of comparative analyses were found to depend strongly on the data set used, especially with more-limited, order-level clades. In fact, with small sample sizes (e.g. <100) results often appeared erratic. Subsampling revealed that sample size has a non-linear effect on the probability of a zero slope for a given relationship. Depending on the species included, results could differ dramatically, especially with small sample sizes. Overall, our findings indicate a need for due diligence when selecting BMR estimates and caution regarding results (even if seemingly significant) with small sample sizes. © 2017 Cambridge Philosophical Society.

Size and consistency of problem-solving consultation outcomes: an empirical analysis.

PubMed

Hurwitz, Jason T; Kratochwill, Thomas R; Serlin, Ronald C

2015-04-01

In this study, we analyzed extant data to evaluate the variability and magnitude of students' behavior change outcomes (academic, social, and behavioral) produced by consultants through problem-solving consultation with teachers. Research questions were twofold: (a) Do consultants produce consistent and sizeable positive student outcomes across their cases as measured through direct and frequent assessment? and (b) What proportion of variability in student outcomes is attributable to consultants? Analyses of extant data collected from problem-solving consultation outcome studies that used single-case, time-series AB designs with multiple participants were analyzed. Four such studies ultimately met the inclusion criteria for the extant data, comprising 124 consultants who worked with 302 school teachers regarding 453 individual students. Consultants constituted the independent variable, while the primary dependent variable was a descriptive effect size based on student behavior change as measured by (a) curriculum-based measures, (b) permanent products, or (c) direct observations. Primary analyses involved visual and statistical evaluation of effect size magnitude and variability observed within and between consultants and studies. Given the nested nature of the data, multilevel analyses were used to assess consultant effects on student outcomes. Results suggest that consultants consistently produced positive effect sizes on average across their cases, but outcomes varied between consultants. Findings also indicated that consultants, teachers, and the corresponding studies accounted for a significant proportion of variability in student outcomes. This investigation advances the use of multilevel and integrative data analyses to evaluate consultation outcomes and extends research on problem-solving consultation, consultant effects, and meta-analysis of case study AB designs. Practical implications for evaluating consultation service delivery in school settings are also discussed. Copyright © 2015 Society for the Study of School Psychology. Published by Elsevier Ltd. All rights reserved.

Maintenance of phenotypic variation: repeatibility, heritability, and size-dependent processes in a wild brook trout population

Treesearch

Benjamin H. Letcher; Jason A Coombs; Keith H. Nislow

2011-01-01

Phenotypic variation in body size can result from within-cohort variation in birth dates, among-individual growth variation and size-selective processes. We explore the relative effects of these processes on the maintenance of wide observed body size variation in stream-dwelling brook trout (Salvelinus fontinalis). Based on the analyses of multiple...

Predicted effect size of lisdexamfetamine treatment of attention deficit/hyperactivity disorder (ADHD) in European adults: Estimates based on indirect analysis using a systematic review and meta-regression analysis.

PubMed

Fridman, M; Hodgkins, P S; Kahle, J S; Erder, M H

2015-06-01

There are few approved therapies for adults with attention-deficit/hyperactivity disorder (ADHD) in Europe. Lisdexamfetamine (LDX) is an effective treatment for ADHD; however, no clinical trials examining the efficacy of LDX specifically in European adults have been conducted. Therefore, to estimate the efficacy of LDX in European adults we performed a meta-regression of existing clinical data. A systematic review identified US- and Europe-based randomized efficacy trials of LDX, atomoxetine (ATX), or osmotic-release oral system methylphenidate (OROS-MPH) in children/adolescents and adults. A meta-regression model was then fitted to the published/calculated effect sizes (Cohen's d) using medication, geographical location, and age group as predictors. The LDX effect size in European adults was extrapolated from the fitted model. Sensitivity analyses performed included using adult-only studies and adding studies with placebo designs other than a standard pill-placebo design. Twenty-two of 2832 identified articles met inclusion criteria. The model-estimated effect size of LDX for European adults was 1.070 (95% confidence interval: 0.738, 1.401), larger than the 0.8 threshold for large effect sizes. The overall model fit was adequate (80%) and stable in the sensitivity analyses. This model predicts that LDX may have a large treatment effect size in European adults with ADHD. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

A Meta-Analysis: School-Based Intervention Programs Targeting Psychosocial Factors for Gifted Racial/Ethnic Minority Students

ERIC Educational Resources Information Center

Woo, Hongryun; Bang, Na Mi; Cauley, Bridget; Choi, Namok

2017-01-01

This meta-analysis of five studies examined the effect of school-based intervention programs on psychosocial well-being of gifted racial/ethnic minority students in K-12 school settings. Analyses determined the overall effect sizes for various intervention programs and compared the effect sizes for subgroups by grade (i.e., elementary vs.…

The Limited Informativeness of Meta-Analyses of Media Effects.

PubMed

Valkenburg, Patti M

2015-09-01

In this issue of Perspectives on Psychological Science, Christopher Ferguson reports on a meta-analysis examining the relationship between children's video game use and several outcome variables, including aggression and attention deficit symptoms (Ferguson, 2015, this issue). In this commentary, I compare Ferguson's nonsignificant effects sizes with earlier meta-analyses on the same topics that yielded larger, significant effect sizes. I argue that Ferguson's choice for partial effects sizes is unjustified on both methodological and theoretical grounds. I then plead for a more constructive debate on the effects of violent video games on children and adolescents. Until now, this debate has been dominated by two camps with diametrically opposed views on the effects of violent media on children. However, even the earliest media effects studies tell us that children can react quite differently to the same media content. Thus, if researchers truly want to understand how media affect children, rather than fight for the presence or absence of effects, they need to adopt a perspective that takes differential susceptibility to media effects more seriously. © The Author(s) 2015.

Effectiveness of online mindfulness-based interventions in improving mental health: A review and meta-analysis of randomised controlled trials.

PubMed

Spijkerman, M P J; Pots, W T M; Bohlmeijer, E T

2016-04-01

Mindfulness-based interventions (MBIs) are increasingly being delivered through the Internet. Whereas numerous meta-analyses have investigated the effectiveness of face-to-face MBIs in the context of mental health and well-being, thus far a quantitative synthesis of the effectiveness of online MBIs is lacking. The aim of this meta-analysis was to estimate the overall effects of online MBIs on mental health. Fifteen randomised controlled trials were included in this study. A random effects model was used to compute pre-post between-group effect sizes, and the study quality of each of the included trials was rated. Results showed that online MBIs have a small but significant beneficial impact on depression (g=0.29), anxiety (g=0.22), well-being (g=0.23) and mindfulness (g=0.32). The largest effect was found for stress, with a moderate effect size (g=0.51). For stress and mindfulness, exploratory subgroup analyses demonstrated significantly higher effect sizes for guided online MBIs than for unguided online MBIs. In addition, meta-regression analysis showed that effect sizes for stress were significantly moderated by the number of intervention sessions. Effect sizes, however, were not significantly related to study quality. The findings indicate that online MBIs have potential to contribute to improving mental health outcomes, particularly stress. Limitations, directions for future research and practical implications are discussed. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Maternal work early in the lives of children and its distal associations with achievement and behavior problems: a meta-analysis.

PubMed

Lucas-Thompson, Rachel G; Goldberg, Wendy A; Prause, JoAnn

2010-11-01

This meta-analysis of 69 studies (1,483 effect sizes) used random effects models to examine maternal employment during infancy/early childhood in relation to 2 major domains of child functioning: achievement and behavior problems. Analyses of studies that spanned 5 decades indicated that, with a few exceptions, early employment was not significantly associated with later achievement or internalizing/externalizing behaviors. The exceptions were for teacher ratings of achievement and internalizing behaviors: Employment was associated with higher achievement and fewer internalizing behaviors. Substantial heterogeneity among the effect sizes prompted examination of moderators. Sample-level moderator analyses pointed to the importance of socioeconomic and contextual variables, with early employment most beneficial when families were challenged by single parenthood or welfare status. Maternal employment during Years 2 and 3 was associated with higher achievement. Some moderator analyses indicated negative effects of employment for middle-class and 2-parent families and for very early employment (child's first year). Associations also differed depending on whether effect sizes were adjusted for contextual variables. Only 1 study-level moderator (sex of first author) was significant after adjusting for other moderators. The small effect size and primarily nonsignificant results for main effects of early maternal employment should allay concerns about mothers working when children are young. However, negative findings associated with employment during the child's first year are compatible with calls for more generous maternal leave policies. Results highlight the importance of social context for identifying under which conditions and for which subgroups early maternal employment is associated with positive or negative child outcomes.

Methodological concerns for meta-analyses of meditation: Comment on Sedlmeier et al. (2012).

PubMed

Orme-Johnson, David W; Dillbeck, Michael C

2014-03-01

We commend Sedlmeier et al. (2012) for their significant undertaking of meta-analysis of all meditation types on all psychological variables, but additional analyses may modify some of their conclusions. Whereas they suggest from visual inspection of funnel diagrams that there may be publication bias of underreporting low-effect studies on the Transcendental Meditation (TM) technique, quantitative tests do not indicate the presence of bias for any type of meditation. We additionally found that there was no significant difference in effect sizes between studies originating from researchers affiliated with a TM organization and studies from other universities. We found that comparison of different types of meditation on their global index was confounded because their global index aggregated different sets of variables for the different groups. That is, using composite indices that only aggregated variables for which each group had at least 3 studies confirmed the authors' conclusion that effect sizes for different research designs were not different, but found that effect sizes for the TM technique were significantly larger than effect sizes for mindfulness meditation or other meditations. We also located 35 studies on the TM technique that appear to meet the authors' inclusion criteria that were missed by their meta-analysis, and several others on important psychosocial behavioral variables, such as job performance, substance abuse, and prison recidivism that were not reviewed. In addition, we suggest that future meta-analyses on psychological variables include cross-validating physiological studies.

Single-case synthesis tools II: Comparing quantitative outcome measures.

PubMed

Zimmerman, Kathleen N; Pustejovsky, James E; Ledford, Jennifer R; Barton, Erin E; Severini, Katherine E; Lloyd, Blair P

2018-03-07

Varying methods for evaluating the outcomes of single case research designs (SCD) are currently used in reviews and meta-analyses of interventions. Quantitative effect size measures are often presented alongside visual analysis conclusions. Six measures across two classes-overlap measures (percentage non-overlapping data, improvement rate difference, and Tau) and parametric within-case effect sizes (standardized mean difference and log response ratio [increasing and decreasing])-were compared to determine if choice of synthesis method within and across classes impacts conclusions regarding effectiveness. The effectiveness of sensory-based interventions (SBI), a commonly used class of treatments for young children, was evaluated. Separately from evaluations of rigor and quality, authors evaluated behavior change between baseline and SBI conditions. SBI were unlikely to result in positive behavior change across all measures except IRD. However, subgroup analyses resulted in variable conclusions, indicating that the choice of measures for SCD meta-analyses can impact conclusions. Suggestions for using the log response ratio in SCD meta-analyses and considerations for understanding variability in SCD meta-analysis conclusions are discussed. Copyright © 2018 Elsevier Ltd. All rights reserved.

Random-effects linear modeling and sample size tables for two special crossover designs of average bioequivalence studies: the four-period, two-sequence, two-formulation and six-period, three-sequence, three-formulation designs.

PubMed

Diaz, Francisco J; Berg, Michel J; Krebill, Ron; Welty, Timothy; Gidal, Barry E; Alloway, Rita; Privitera, Michael

2013-12-01

Due to concern and debate in the epilepsy medical community and to the current interest of the US Food and Drug Administration (FDA) in revising approaches to the approval of generic drugs, the FDA is currently supporting ongoing bioequivalence studies of antiepileptic drugs, the EQUIGEN studies. During the design of these crossover studies, the researchers could not find commercial or non-commercial statistical software that quickly allowed computation of sample sizes for their designs, particularly software implementing the FDA requirement of using random-effects linear models for the analyses of bioequivalence studies. This article presents tables for sample-size evaluations of average bioequivalence studies based on the two crossover designs used in the EQUIGEN studies: the four-period, two-sequence, two-formulation design, and the six-period, three-sequence, three-formulation design. Sample-size computations assume that random-effects linear models are used in bioequivalence analyses with crossover designs. Random-effects linear models have been traditionally viewed by many pharmacologists and clinical researchers as just mathematical devices to analyze repeated-measures data. In contrast, a modern view of these models attributes an important mathematical role in theoretical formulations in personalized medicine to them, because these models not only have parameters that represent average patients, but also have parameters that represent individual patients. Moreover, the notation and language of random-effects linear models have evolved over the years. Thus, another goal of this article is to provide a presentation of the statistical modeling of data from bioequivalence studies that highlights the modern view of these models, with special emphasis on power analyses and sample-size computations.

Intelligence, birth order, and family size.

PubMed

Kanazawa, Satoshi

2012-09-01

The analysis of the National Child Development Study in the United Kingdom (n = 17,419) replicates some earlier findings and shows that genuine within-family data are not necessary to make the apparent birth-order effect on intelligence disappear. Birth order is not associated with intelligence in between-family data once the number of siblings is statistically controlled. The analyses support the admixture hypothesis, which avers that the apparent birth-order effect on intelligence is an artifact of family size, and cast doubt on the confluence and resource dilution models, both of which claim that birth order has a causal influence on children's cognitive development. The analyses suggest that birth order has no genuine causal effect on general intelligence.

The Impact of APA and AERA Guidelines on Effect Size Reporting

ERIC Educational Resources Information Center

Peng, Chao-Ying Joanne; Chen, Li-Ting; Chiang, Hsu-Min; Chiang, Yi-Chen

2013-01-01

Given the long history of effect size (ES) indices (Olejnik and Algina, "Contemporary Educational Psychology," 25, 241-286 2000) and various attempts by APA and AERA to encourage the reporting and interpretation of ES to supplement findings from inferential statistical analyses, it is essential to document the impact of APA and AERA standards on…

Targeted On-Demand Team Performance App Development

DTIC Science & Technology

2016-10-01

from three sites; 6) Preliminary analysis indicates larger than estimate effect size and study is sufficiently powered for generalizable outcomes...statistical analyses, and examine any resulting qualitative data for trends or connections to statistical outcomes. On Schedule 21 Predictive...Preliminary analysis indicates larger than estimate effect size and study is sufficiently powered for generalizable outcomes.  What opportunities for

On the number of New World founders: a population genetic portrait of the peopling of the Americas.

PubMed

Hey, Jody

2005-06-01

The founding of New World populations by Asian peoples is the focus of considerable archaeological and genetic research, and there persist important questions on when and how these events occurred. Genetic data offer great potential for the study of human population history, but there are significant challenges in discerning distinct demographic processes. A new method for the study of diverging populations was applied to questions on the founding and history of Amerind-speaking Native American populations. The model permits estimation of founding population sizes, changes in population size, time of population formation, and gene flow. Analyses of data from nine loci are consistent with the general portrait that has emerged from archaeological and other kinds of evidence. The estimated effective size of the founding population for the New World is fewer than 80 individuals, approximately 1% of the effective size of the estimated ancestral Asian population. By adding a splitting parameter to population divergence models it becomes possible to develop detailed portraits of human demographic history. Analyses of Asian and New World data support a model of a recent founding of the New World by a population of quite small effective size.

Evaluation of Bias-Variance Trade-Off for Commonly Used Post-Summarizing Normalization Procedures in Large-Scale Gene Expression Studies

PubMed Central

Qiu, Xing; Hu, Rui; Wu, Zhixin

2014-01-01

Normalization procedures are widely used in high-throughput genomic data analyses to remove various technological noise and variations. They are known to have profound impact to the subsequent gene differential expression analysis. Although there has been some research in evaluating different normalization procedures, few attempts have been made to systematically evaluate the gene detection performances of normalization procedures from the bias-variance trade-off point of view, especially with strong gene differentiation effects and large sample size. In this paper, we conduct a thorough study to evaluate the effects of normalization procedures combined with several commonly used statistical tests and MTPs under different configurations of effect size and sample size. We conduct theoretical evaluation based on a random effect model, as well as simulation and biological data analyses to verify the results. Based on our findings, we provide some practical guidance for selecting a suitable normalization procedure under different scenarios. PMID:24941114

Why herd size matters - mitigating the effects of livestock crashes.

PubMed

Næss, Marius Warg; Bårdsen, Bård-Jørgen

2013-01-01

Analysing the effect of pastoral risk management strategies provides insights into a system of subsistence that have persevered in marginal areas for hundreds to thousands of years and may shed light into the future of around 200 million households in the face of climate change. This study investigated the efficiency of herd accumulation as a buffer strategy by analysing changes in livestock holdings during an environmental crisis in the Saami reindeer husbandry in Norway. We found a positive relationship between: (1) pre- and post-collapse herd size; and (2) pre-collapse herd size and the number of animals lost during the collapse, indicating that herd accumulation is an effective but costly strategy. Policies that fail to incorporate the risk-beneficial aspect of herd accumulation will have a limited effect and may indeed fail entirely. In the context of climate change, official policies that incorporate pastoral risk management strategies may be the only solution for ensuring their continued existence.

A Meta-Analytic Review of Gender Variations in Children's Language Use: Talkativeness, Affiliative Speech, and Assertive Speech

ERIC Educational Resources Information Center

Leaper, Campbell; Smith, Tara E.

2004-01-01

Three sets of meta-analyses examined gender effects on children's language use. Each set of analyses considered an aspect of speech that is considered to be gender typed: talkativeness, affiliative speech, and assertive speech. Statistically significant average effect sizes were obtained with all three language constructs. On average, girls were…

Meta-analyses including data from observational studies.

PubMed

O'Connor, Annette M; Sargeant, Jan M

2014-02-15

Observational studies represent a wide group of studies where the disease or condition of interest is naturally occurring and the investigator does not control allocation to interventions or exposures. Observational studies are used to test hypotheses about the efficacy of interventions or about exposure-disease relationships, to estimate incidence or prevalence of conditions, and to assess the sensitivity and specificity of diagnostic assays. Experimental-study designs and randomized controlled trials (RCTs) can also contribute to the body of evidence about such questions. Meta-analyses (either with or without systematic reviews) aim to combine information from primary research studies to better describe the entire body of work. The aim of meta-analyses may be to obtain a summary effect size, or to understand factors that affect effect sizes. In this paper, we discuss the role of observational studies in meta-analysis questions and some factors to consider when deciding whether a meta-analysis should include results from such studies. Our suggestion is that one should only include studies that are not at high risk of inherent bias when calculating a summary effect size. Study design however can be a meaningful variable in assessment of outcome heterogeneity. Copyright © 2013 Elsevier B.V. All rights reserved.

Quasi-experimental study designs series-paper 10: synthesizing evidence for effects collected from quasi-experimental studies presents surmountable challenges.

PubMed

Becker, Betsy Jane; Aloe, Ariel M; Duvendack, Maren; Stanley, T D; Valentine, Jeffrey C; Fretheim, Atle; Tugwell, Peter

2017-09-01

To outline issues of importance to analytic approaches to the synthesis of quasi-experiments (QEs) and to provide a statistical model for use in analysis. We drew on studies of statistics, epidemiology, and social-science methodology to outline methods for synthesis of QE studies. The design and conduct of QEs, effect sizes from QEs, and moderator variables for the analysis of those effect sizes were discussed. Biases, confounding, design complexities, and comparisons across designs offer serious challenges to syntheses of QEs. Key components of meta-analyses of QEs were identified, including the aspects of QE study design to be coded and analyzed. Of utmost importance are the design and statistical controls implemented in the QEs. Such controls and any potential sources of bias and confounding must be modeled in analyses, along with aspects of the interventions and populations studied. Because of such controls, effect sizes from QEs are more complex than those from randomized experiments. A statistical meta-regression model that incorporates important features of the QEs under review was presented. Meta-analyses of QEs provide particular challenges, but thorough coding of intervention characteristics and study methods, along with careful analysis, should allow for sound inferences. Copyright © 2017 Elsevier Inc. All rights reserved.

Smaller predator-prey body size ratios in longer food chains.

PubMed Central

Jennings, Simon; Warr, Karema J

2003-01-01

Maximum food-chain length has been correlated with resource availability, ecosystem size, environmental stability and colonization history. Some of these correlations may result from environmental effects on predator-prey body size ratios. We investigate relationships between maximum food-chain length, predator-prey mass ratios, primary production and environmental stability in marine food webs with a natural history of community assembly. Our analyses provide empirical evidence that smaller mean predator-prey body size ratios are characteristic of more stable environments and that food chains are longer when mean predator-prey body size ratios are small. We conclude that environmental effects on predator-prey body size ratios contribute to observed differences in maximum food-chain length. PMID:12965034

Size and modal analyses of fines and ultrafines from some Apollo 17 samples

NASA Technical Reports Server (NTRS)

Greene, G. M.; King, D. T., Jr.; Banholzer, G. S., Jr.; King, E. A.

1975-01-01

Scanning electron and optical microscopy techniques have been used to determine the grain-size frequency distributions and morphology-based modal analyses of fine and ultrafine fractions of some Apollo 17 regolith samples. There are significant and large differences between the grain-size frequency distributions of the less than 10-micron size fraction of Apollo 17 samples, but there are no clear relations to the local geologic setting from which individual samples have been collected. This may be due to effective lateral mixing of regolith particles in this size range by micrometeoroid impacts. None of the properties of the frequency distributions support the idea of selective transport of any fine grain-size fraction, as has been proposed by other workers. All of the particle types found in the coarser size fractions also occur in the less than 10-micron particles. In the size range from 105 to 10 microns there is a strong tendency for the percentage of regularly shaped glass to increase as the graphic mean grain size of the less than 1-mm size fraction decreases, both probably being controlled by exposure age.

Residual Stresses and Critical Initial Flaw Size Analyses of Welds

NASA Technical Reports Server (NTRS)

Brust, Frederick W.; Raju, Ivatury, S.; Dawocke, David S.; Cheston, Derrick

2009-01-01

An independent assessment was conducted to determine the critical initial flaw size (CIFS) for the flange-to-skin weld in the Ares I-X Upper Stage Simulator (USS). A series of weld analyses are performed to determine the residual stresses in a critical region of the USS. Weld residual stresses both increase constraint and mean stress thereby having an important effect on the fatigue life. The purpose of the weld analyses was to model the weld process using a variety of sequences to determine the 'best' sequence in terms of weld residual stresses and distortions. The many factors examined in this study include weld design (single-V, double-V groove), weld sequence, boundary conditions, and material properties, among others. The results of this weld analysis are included with service loads to perform a fatigue and critical initial flaw size evaluation.

The Effective Dynamic Ranges for Glaucomatous Visual Field Progression With Standard Automated Perimetry and Stimulus Sizes III and V.

PubMed

Wall, Michael; Zamba, Gideon K D; Artes, Paul H

2018-01-01

It has been shown that threshold estimates below approximately 20 dB have little effect on the ability to detect visual field progression in glaucoma. We aimed to compare stimulus size V to stimulus size III, in areas of visual damage, to confirm these findings by using (1) a different dataset, (2) different techniques of progression analysis, and (3) an analysis to evaluate the effect of censoring on mean deviation (MD). In the Iowa Variability in Perimetry Study, 120 glaucoma subjects were tested every 6 months for 4 years with size III SITA Standard and size V Full Threshold. Progression was determined with three complementary techniques: pointwise linear regression (PLR), permutation of PLR, and linear regression of the MD index. All analyses were repeated on "censored'' datasets in which threshold estimates below a given criterion value were set to equal the criterion value. Our analyses confirmed previous observations that threshold estimates below 20 dB contribute much less to visual field progression than estimates above this range. These findings were broadly similar with stimulus sizes III and V. Censoring of threshold values < 20 dB has relatively little impact on the rates of visual field progression in patients with mild to moderate glaucoma. Size V, which has lower retest variability, performs at least as well as size III for longitudinal glaucoma progression analysis and appears to have a larger useful dynamic range owing to the upper sensitivity limit being higher.

Race and diurnal blood pressure patterns. A review and meta-analysis.

PubMed

Profant, J; Dimsdale, J E

1999-05-01

Investigators have reported variable findings regarding the role of race in diurnal blood pressure patterns. We performed a review and meta-analysis of this literature to identify the overall effect of race on circadian blood pressure patterns. Eighteen studies involving 2852 participants were reviewed. Meta-analyses were conducted using effect sizes calculated from the data provided directly in the study reports. Separate meta-analyses were conducted on effect sizes for differences between blacks and whites in daytime and nighttime systolic and diastolic blood pressure and nocturnal dip in systolic and diastolic blood pressure. To evaluate discrepancies in findings from studies involving American versus non-American blacks, overall meta-analyses as well as within-subset meta-analyses of black/white differences were conducted for comparisons involving American and non-American blacks. Results of overall meta-analyses indicate that blacks experience higher levels of systolic and diastolic blood pressure, both at night and during the day. These differences were significantly greater at night than during the day (P<0.05). Results of within-subset analyses involving American blacks mirrored those for all black/white comparisons, except that the effect of race on nocturnal dip, ie, that American blacks experienced less of a dip in both systolic and diastolic blood pressure at night, was significant (P<0.05). In contrast, the effect of race on nocturnal dip was not significant for comparisons involving non-American blacks. These results suggest a consistent difference in the chronobiology of blood pressure, particularly in American blacks.

Confidence crisis of results in biomechanics research.

PubMed

Knudson, Duane

2017-11-01

Many biomechanics studies have small sample sizes and incorrect statistical analyses, so reporting of inaccurate inferences and inflated magnitude of effects are common in the field. This review examines these issues in biomechanics research and summarises potential solutions from research in other fields to increase the confidence in the experimental effects reported in biomechanics. Authors, reviewers and editors of biomechanics research reports are encouraged to improve sample sizes and the resulting statistical power, improve reporting transparency, improve the rigour of statistical analyses used, and increase the acceptance of replication studies to improve the validity of inferences from data in biomechanics research. The application of sports biomechanics research results would also improve if a larger percentage of unbiased effects and their uncertainty were reported in the literature.

Meditation programs for veterans with posttraumatic stress disorder: Aggregate findings from a multi-site evaluation.

PubMed

Heffner, Kathi L; Crean, Hugh F; Kemp, Jan E

2016-05-01

Interest in meditation to manage posttraumatic stress disorder (PTSD) symptoms is increasing. Few studies have examined the effectiveness of meditation programs offered to Veterans within Department of Veterans Affairs (VA) mental health services. The current study addresses this gap using data from a multisite VA demonstration project. Evaluation data collected at 6 VA sites (N = 391 Veterans) before and after a meditation program, and a treatment-as-usual (TAU) program, were examined here using random effects meta-analyses. Site-specific and aggregate between group effect sizes comparing meditation programs to TAU were determined for PTSD severity measured by clinical interview and self-report. Additional outcomes included experiential avoidance and mindfulness. In aggregate, analyses showed medium effect sizes for meditation programs compared to TAU for PTSD severity (clinical interview: effect size (ES) = -0.32; self-report: ES = -0.39). Similarly sized effects of meditation programs were found for overall mindfulness (ES = 0.41) and 1 specific aspect of mindfulness, nonreactivity to inner experience (ES = .37). Additional findings suggested meditation type and program completion differences each moderated program effects. VA-sponsored meditation programs show promise for reducing PTSD severity in Veterans receiving mental health services. Where meditation training fits within mental health services, and for whom programs will be of interest and effective, require further clarification. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Hospital level analysis to improve patient flow.

PubMed

Khanna, Sankalp; Boyle, Justin; Good, Norm; Bugden, Simon; Scott, Mark

2013-01-01

The complexity of hospital operations ensures that one-size-fits-all solutions seldom work. As hospitals turn to evidence based strategies to redesign flow, it is critical that they tailor the strategies to suit their individual service. This paper analyses the effect of hospital occupancy on inpatient and emergency department patient flow parameters at the Caboolture hospital in Queensland, Australia, and identifies critical levels, or choke points, that result in performance decline. The effect of weekdays and weekends on patient flow is also investigated. We compare these findings to a previous study that has analysed patient flow across Queensland hospitals grouped by size, and discover several differences in the interaction between rising occupancy and patient flow parameters including rates of patient flow, length of stay, and access block. We also identify significantly higher choke points for Caboolture hospital as compared to other similarly sized Queensland hospitals, which suggest that patient flow here can be redesigned to operate at higher levels of occupancy without degrading flow performance. The findings support arguments for hospitals to analyse patient flow at a service level to deliver optimum service improvement.

Effects of morphological Family Size for young readers.

PubMed

Perdijk, Kors; Schreuder, Robert; Baayen, R Harald; Verhoeven, Ludo

2012-09-01

Dutch children, from the second and fourth grade of primary school, were each given a visual lexical decision test on 210 Dutch monomorphemic words. After removing words not recognized by a majority of the younger group, (lexical) decisions were analysed by mixed-model regression methods to see whether morphological Family Size influenced decision times over and above several other covariates. The effect of morphological Family Size on decision time was mixed: larger families led to significantly faster decision times for the second graders but not for the fourth graders. Since facilitative effects on decision times had been found for adults, we offer a developmental account to explain the absence of an effect of Family Size on decision times for fourth graders. ©2011 The British Psychological Society.

A meta-analysis of perceptions of defeat and entrapment in depression, anxiety problems, posttraumatic stress disorder, and suicidality.

PubMed

Siddaway, Andy P; Taylor, Peter J; Wood, Alex M; Schulz, Joerg

2015-09-15

There is a burgeoning literature examining perceptions of being defeated or trapped in different psychiatric disorders. The disorders most frequently examined to date are depression, anxiety problems, posttraumatic stress disorder (PTSD), and suicidality. To quantify the size and consistency of perceptions of defeat and entrapment in depression, anxiety problems, PTSD and suicidality, test for differences across psychiatric disorders, and examine potential moderators and publication bias. Random-effects meta-analyses based on Pearson's correlation coefficient r. Forty studies were included in the meta-analysis (n = 10,072). Perceptions of defeat and entrapment were strong (around r = 0.60) and similar in size across all four psychiatric disorders. Perceptions of defeat were particularly strong in depression (r = 0.73). There was no between-study heterogeneity; therefore moderator analyses were conducted in an exploratory fashion. There was no evidence of publication bias. Analyses were cross-sectional, which precludes establishing temporal precedence or causality. Some of the meta-analyses were based on relatively small numbers of effect sizes, which may limit their generalisability. Perceptions of defeat and entrapment are clinically important in depression, anxiety problems, PTSD, and suicidality. Similar-sized, strong relationships across four different psychiatric disorders could suggest that perceptions of defeat and entrapment are transdiagnostic constructs. The results suggest that clinicians and researchers need to become more aware of perceptions of defeat and entrapment. Copyright © 2015 Elsevier B.V. All rights reserved.

Effects of Recombinant Human Growth Hormone for Osteoporosis: Systematic Review and Meta-Analysis.

PubMed

Atkinson, Hayden F; Moyer, Rebecca F; Yacoub, Daniel; Coughlin, Dexter; Birmingham, Trevor B

2017-03-01

Our objective was to evaluate the efficacy of recombinant human growth hormone (GH) on bone mineral density (BMD) in persons age 50 and older, with normal pituitary function, with or at risk for developing osteoporosis. We systematically reviewed randomized clinical trials (RCTs), searching six databases, and conducted meta-analyses to examine GH effects on BMD of the lumbar spine and femoral neck. Data for fracture incidence, bone metabolism biomarkers, and adverse events were also extracted and analysed. Thirteen RCTs met the eligibility criteria. Pooled effect sizes suggested no significant GH effect on BMD. Pooled effect sizes were largest, but nonsignificant, when compared to placebo. GH had a significant effect on several bone metabolism biomarkers. A significantly higher rate of adverse events was observed in the GH groups. Meta-analysis of RCTs suggests that GH treatment for persons with or at risk for developing osteoporosis results in very small, nonsignificant increases in BMD.

A Meta-Meta-Analysis: Empirical Review of Statistical Power, Type I Error Rates, Effect Sizes, and Model Selection of Meta-Analyses Published in Psychology

ERIC Educational Resources Information Center

Cafri, Guy; Kromrey, Jeffrey D.; Brannick, Michael T.

2010-01-01

This article uses meta-analyses published in "Psychological Bulletin" from 1995 to 2005 to describe meta-analyses in psychology, including examination of statistical power, Type I errors resulting from multiple comparisons, and model choice. Retrospective power estimates indicated that univariate categorical and continuous moderators, individual…

Effects of a web-based tailored multiple-lifestyle intervention for adults: a two-year randomized controlled trial comparing sequential and simultaneous delivery modes.

PubMed

Schulz, Daniela N; Kremers, Stef P J; Vandelanotte, Corneel; van Adrichem, Mathieu J G; Schneider, Francine; Candel, Math J J M; de Vries, Hein

2014-01-27

Web-based computer-tailored interventions for multiple health behaviors can have a significant public health impact. Yet, few randomized controlled trials have tested this assumption. The objective of this paper was to test the effects of a sequential and simultaneous Web-based tailored intervention on multiple lifestyle behaviors. A randomized controlled trial was conducted with 3 tailoring conditions (ie, sequential, simultaneous, and control conditions) in the Netherlands in 2009-2012. Follow-up measurements took place after 12 and 24 months. The intervention content was based on the I-Change model. In a health risk appraisal, all respondents (N=5055) received feedback on their lifestyle behaviors that indicated whether they complied with the Dutch guidelines for physical activity, vegetable consumption, fruit consumption, alcohol intake, and smoking. Participants in the sequential (n=1736) and simultaneous (n=1638) conditions received tailored motivational feedback to change unhealthy behaviors one at a time (sequential) or all at the same time (simultaneous). Mixed model analyses were performed as primary analyses; regression analyses were done as sensitivity analyses. An overall risk score was used as outcome measure, then effects on the 5 individual lifestyle behaviors were assessed and a process evaluation was performed regarding exposure to and appreciation of the intervention. Both tailoring strategies were associated with small self-reported behavioral changes. The sequential condition had the most significant effects compared to the control condition after 12 months (T1, effect size=0.28). After 24 months (T2), the simultaneous condition was most effective (effect size=0.18). All 5 individual lifestyle behaviors changed over time, but few effects differed significantly between the conditions. At both follow-ups, the sequential condition had significant changes in smoking abstinence compared to the simultaneous condition (T1 effect size=0.31; T2 effect size=0.41). The sequential condition was more effective in decreasing alcohol consumption than the control condition at 24 months (effect size=0.27). Change was predicted by the amount of exposure to the intervention (total visiting time: beta=-.06; P=.01; total number of visits: beta=-.11; P<.001). Both interventions were appreciated well by respondents without significant differences between conditions. Although evidence was found for the effectiveness of both programs, no simple conclusive finding could be drawn about which intervention mode was more effective. The best kind of intervention may depend on the behavior that is targeted or on personal preferences and motivation. Further research is needed to identify moderators of intervention effectiveness. The results need to be interpreted in view of the high and selective dropout rates, multiple comparisons, and modest effect sizes. However, a large number of people were reached at low cost and behavioral change was achieved after 2 years. Nederlands Trial Register: NTR 2168; http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=2168 (Archived by WebCite at http://www.webcitation.org/6MbUqttYB).

Fishing and temperature effects on the size structure of exploited fish stocks.

PubMed

Tu, Chen-Yi; Chen, Kuan-Ting; Hsieh, Chih-Hao

2018-05-08

Size structure of fish stock plays an important role in maintaining sustainability of the population. Size distribution of an exploited stock is predicted to shift toward small individuals caused by size-selective fishing and/or warming; however, their relative contribution remains relatively unexplored. In addition, existing analyses on size structure have focused on univariate size-based indicators (SBIs), such as mean length, evenness of size classes, or the upper 95-percentile of the length frequency distribution; these approaches may not capture full information of size structure. To bridge the gap, we used the variation partitioning approach to examine how the size structure (composition of size classes) responded to fishing, warming and the interaction. We analyzed 28 exploited stocks in the West US, Alaska and North Sea. Our result shows fishing has the most prominent effect on the size structure of the exploited stocks. In addition, the fish stocks experienced higher variability in fishing is more responsive to the temperature effect in their size structure, suggesting that fishing may elevate the sensitivity of exploited stocks in responding to environmental effects. The variation partitioning approach provides complementary information to univariate SBIs in analyzing size structure.

A meta-analysis of neuropsychological outcome after mild traumatic brain injury: re-analyses and reconsiderations of Binder et al. (1997), Frencham et al. (2005), and Pertab et al. (2009).

PubMed

Rohling, Martin L; Binder, Laurence M; Demakis, George J; Larrabee, Glenn J; Ploetz, Danielle M; Langhinrichsen-Rohling, Jennifer

2011-05-01

The meta-analytic findings of Binder et al. (1997) and Frencham et al. (2005) showed that the neuropsychological effect of mild traumatic brain injury (mTBI) was negligible in adults by 3 months post injury. Pertab et al. (2009) reported that verbal paired associates, coding tasks, and digit span yielded significant differences between mTBI and control groups. We re-analyzed data from the 25 studies used in the prior meta-analyses, correcting statistical and methodological limitations of previous efforts, and analyzed the chronicity data by discrete epochs. Three months post injury the effect size of -0.07 was not statistically different from zero and similar to that which has been found in several other meta-analyses (Belanger et al., 2005; Schretlen & Shapiro, 2003). The effect size 7 days post injury was -0.39. The effect of mTBI immediately post injury was largest on Verbal and Visual Memory domains. However, 3 months post injury all domains improved to show non-significant effect sizes. These findings indicate that mTBI has an initial small effect on neuropsychological functioning that dissipates quickly. The evidence of recovery in the present meta-analysis is consistent with previous conclusions of both Binder et al. and Frencham et al. Our findings may not apply to people with a history of multiple concussions or complicated mTBIs.

Physical capital and the embodied nature of income inequality: gender differences in the effect of body size on workers' incomes in Canada.

PubMed

Perks, Thomas

2012-02-01

This study assesses the effects of body size--measured using the body mass index--on the income attainment of female and male workers in Canada. Using data from a national representative sample of Canadians, multivariate analyses show that, for female workers, the body size-income relationship is negative. However, for male workers, the body size-income relationship is positive and nonlinear. Using Bourdieu's conceptualization of physical capital, and Shilling's extension of it, it is argued that these results are suggestive of the relative importance of body size to the production and continuation of gender income inequality in Canada.

Effect Size Analyses of Souvenaid in Patients with Alzheimer's Disease.

PubMed

Cummings, Jeffrey; Scheltens, Philip; McKeith, Ian; Blesa, Rafael; Harrison, John E; Bertolucci, Paulo H F; Rockwood, Kenneth; Wilkinson, David; Wijker, Wouter; Bennett, David A; Shah, Raj C

2017-01-01

Souvenaid® (uridine monophosphate, docosahexaenoic acid, eicosapentaenoic acid, choline, phospholipids, folic acid, vitamins B12, B6, C, and E, and selenium), was developed to support the formation and function of neuronal membranes. To determine effect sizes observed in clinical trials of Souvenaid and to calculate the number needed to treat to show benefit or harm. Data from all three reported randomized controlled trials of Souvenaid in Alzheimer's disease (AD) dementia (Souvenir I, Souvenir II, and S-Connect) and an open-label extension study were included in analyses of effect size for cognitive, functional, and behavioral outcomes. Effect size was determined by calculating Cohen's d statistic (or Cramér's V method for nominal data), number needed to treat and number needed to harm. Statistical calculations were performed for the intent-to-treat populations. In patients with mild AD, effect sizes were 0.21 (95% confidence intervals: -0.06, 0.49) for the primary outcome in Souvenir II (neuropsychological test battery memory z-score) and 0.20 (0.10, 0.34) for the co-primary outcome of Souvenir I (Wechsler memory scale delayed recall). No effect was shown on cognition in patients with mild-to-moderate AD (S-Connect). The number needed to treat (6 and 21 for Souvenir I and II, respectively) and high number needed to harm values indicate a favorable harm:benefit ratio for Souvenaid versus control in patients with mild AD. The favorable safety profile and impact on outcome measures converge to corroborate the putative mode of action and demonstrate that Souvenaid can achieve clinically detectable effects in patients with early AD.

Long-distance plant dispersal to North Atlantic islands: colonization routes and founder effect

PubMed Central

Alsos, Inger Greve; Ehrich, Dorothee; Eidesen, Pernille Bronken; Solstad, Heidi; Westergaard, Kristine Bakke; Schönswetter, Peter; Tribsch, Andreas; Birkeland, Siri; Elven, Reidar; Brochmann, Christian

2015-01-01

Long-distance dispersal (LDD) processes influence the founder effect on islands. We use genetic data for 25 Atlantic species and similarities among regional floras to analyse colonization, and test whether the genetic founder effect on five islands is associated with dispersal distance, island size and species traits. Most species colonized postglacially via multiple dispersal events from several source regions situated 280 to >3000 km away, and often not from the closest ones. A strong founder effect was observed for insect-pollinated mixed maters, and it increased with dispersal distance and decreased with island size in accordance with the theory of island biogeography. Only a minor founder effect was observed for wind-pollinated outcrossing species. Colonization patterns were largely congruent, indicating that despite the importance of stochasticity, LDD is mainly determined by common factors, probably dispersal vectors. Our findings caution against a priori assuming a single, close source region in biogeographic analyses. PMID:25876627

The Effective Dynamic Ranges for Glaucomatous Visual Field Progression With Standard Automated Perimetry and Stimulus Sizes III and V

PubMed Central

Zamba, Gideon K. D.; Artes, Paul H.

2018-01-01

Purpose It has been shown that threshold estimates below approximately 20 dB have little effect on the ability to detect visual field progression in glaucoma. We aimed to compare stimulus size V to stimulus size III, in areas of visual damage, to confirm these findings by using (1) a different dataset, (2) different techniques of progression analysis, and (3) an analysis to evaluate the effect of censoring on mean deviation (MD). Methods In the Iowa Variability in Perimetry Study, 120 glaucoma subjects were tested every 6 months for 4 years with size III SITA Standard and size V Full Threshold. Progression was determined with three complementary techniques: pointwise linear regression (PLR), permutation of PLR, and linear regression of the MD index. All analyses were repeated on “censored'' datasets in which threshold estimates below a given criterion value were set to equal the criterion value. Results Our analyses confirmed previous observations that threshold estimates below 20 dB contribute much less to visual field progression than estimates above this range. These findings were broadly similar with stimulus sizes III and V. Conclusions Censoring of threshold values < 20 dB has relatively little impact on the rates of visual field progression in patients with mild to moderate glaucoma. Size V, which has lower retest variability, performs at least as well as size III for longitudinal glaucoma progression analysis and appears to have a larger useful dynamic range owing to the upper sensitivity limit being higher. PMID:29356822

A systematic meta-review of evaluations of youth violence prevention programs: Common and divergent findings from 25 years of meta-analyses and systematic reviews☆

PubMed Central

Matjasko, Jennifer L.; Vivolo-Kantor, Alana M.; Massetti, Greta M.; Holland, Kristin M.; Holt, Melissa K.; Cruz, Jason Dela

2018-01-01

Violence among youth is a pervasive public health problem. In order to make progress in reducing the burden of injury and mortality that result from youth violence, it is imperative to identify evidence-based programs and strategies that have a significant impact on violence. There have been many rigorous evaluations of youth violence prevention programs. However, the literature is large, and it is difficult to draw conclusions about what works across evaluations from different disciplines, contexts, and types of programs. The current study reviews the meta-analyses and systematic reviews published prior to 2009 that synthesize evaluations of youth violence prevention programs. This meta-review reports the findings from 37 meta-analyses and 15 systematic reviews; the included reviews were coded on measures of the social ecology, prevention approach, program type, and study design. A majority of the meta-analyses and systematic reviews were found to demonstrate moderate program effects. Meta-analyses yielded marginally smaller effect sizes compared to systematic reviews, and those that included programs targeting family factors showed marginally larger effects than those that did not. In addition, there are a wide range of individual/family, program, and study moderators of program effect sizes. Implications of these findings and suggestions for future research are discussed. PMID:29503594

Packaging interventions to increase medication adherence: systematic review and meta-analysis

PubMed Central

Conn, Vicki S.; Ruppar, Todd M.; Chan, Keith C.; Dunbar-Jacob, Jacqueline; Pepper, Ginette A.; De Geest, Sabina

2015-01-01

Objective Inadequate medication adherence is a widespread problem that contributes to increase chronic disease complications and health care expenditures. Packaging interventions using pill boxes and blister packs have been widely recommended to address the medication adherence issue. This meta-analysis review determined the overall effect of packaging interventions on medication adherence and health outcomes. In addition, we tested whether effects vary depending on intervention, sample, and design characteristics. Research design and methods Extensive literature search strategies included examination of 13 computerized databases and 19 research registries, hand searches of 57 journal, and author and ancestry searches. Eligible studies included either pill-boxes or blister packaging interventions to increase medication adherence. Primary study characteristics and outcomes were reliably coded. Random-effects analyses were used to calculate overall effect sizes and conduct moderator analyses. Results Data were synthesized across 22,858 subjects from 52 reports. The overall mean weighted standardized difference effect size for two-group comparisons was 0.593 (favoring treatment over control), which is consistent with the mean of 71% adherence for treatment subjects compared to 63% among control subjects. We found using moderator analyses that interventions were most effective when they used blister packs and were delivered in pharmacies, while interventions were less effective when studies included older subjects and those with cognitive impairment. Methodological moderator analyses revealed significantly larger effect sizes in studies reporting continuous data outcomes instead of dichotomous results and in studies using pharmacy refill medication adherence measures as compared to studies with self-report measures. Conclusions Overall, meta-analysis findings support the use of packaging interventions to effectively increase medication adherence. Limitations of the study include the exclusion of packaging interventions other than pill boxes and blister packs, evidence of publication bias, and primary study sparse reporting of health outcomes and potentially interesting moderating variables such as the number of prescribed medications. PMID:25333709

Variables associated with achievement in higher education: A systematic review of meta-analyses.

PubMed

Schneider, Michael; Preckel, Franzis

2017-06-01

The last 2 decades witnessed a surge in empirical studies on the variables associated with achievement in higher education. A number of meta-analyses synthesized these findings. In our systematic literature review, we included 38 meta-analyses investigating 105 correlates of achievement, based on 3,330 effect sizes from almost 2 million students. We provide a list of the 105 variables, ordered by the effect size, and summary statistics for central research topics. The results highlight the close relation between social interaction in courses and achievement. Achievement is also strongly associated with the stimulation of meaningful learning by presenting information in a clear way, relating it to the students, and using conceptually demanding learning tasks. Instruction and communication technology has comparably weak effect sizes, which did not increase over time. Strong moderator effects are found for almost all instructional methods, indicating that how a method is implemented in detail strongly affects achievement. Teachers with high-achieving students invest time and effort in designing the microstructure of their courses, establish clear learning goals, and employ feedback practices. This emphasizes the importance of teacher training in higher education. Students with high achievement are characterized by high self-efficacy, high prior achievement and intelligence, conscientiousness, and the goal-directed use of learning strategies. Barring the paucity of controlled experiments and the lack of meta-analyses on recent educational innovations, the variables associated with achievement in higher education are generally well investigated and well understood. By using these findings, teachers, university administrators, and policymakers can increase the effectivity of higher education. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Role of grain-size in phyllonitisation: Insights from mineralogy, microstructures, strain analyses and numerical modeling

NASA Astrophysics Data System (ADS)

Bose, Narayan; Dutta, Dripta; Mukherjee, Soumyajit

2018-07-01

Brittle Y- and P-planes exist in an exposure of greywacke in the Garhwal Lesser Himalaya, India. Although, Y-planes are well developed throughout, the P-planes are prominent only in some parts (domain-A), and not elsewhere (domain-B). To investigate why the P-planes developed selectively, the following studies were undertaken: 1. Clay-separated XRD analyses: clinochlore and illite are present in both the domains. 2. Strain analyses by Rf-φ method: it deduces strain magnitudes of ∼1.8 for the ductile deformed quartz grains from both the domains A and B. 3. Grain size analyses of quartz clasts: domain-A is mostly composed of finer grains (area up to 40,000 μm2), whereas domain-B consists of a population of coarser grains (area >45,000 μm2). A 2D finite element modeling of linear elastic material was performed using COMSOL software to investigate the control of grain-size variation on the generation brittle shear planes. The results of numerical modeling corroborate the known fact that an increase in grain-size reduces the elastic strain energy density. A broader grain-size distribution increases the effects of diffusion creep and resists the onset of dislocation creep. Thus, rocks with coarser grain population (domain B) tend to resist the generation of shear fractures, unlike their fine-grained counterpart (domain A).

Using Meta-analyses for Comparative Effectiveness Research

PubMed Central

Ruppar, Todd M.; Phillips, Lorraine J.; Chase, Jo-Ana D.

2012-01-01

Comparative effectiveness research seeks to identify the most effective interventions for particular patient populations. Meta-analysis is an especially valuable form of comparative effectiveness research because it emphasizes the magnitude of intervention effects rather than relying on tests of statistical significance among primary studies. Overall effects can be calculated for diverse clinical and patient-centered variables to determine the outcome patterns. Moderator analyses compare intervention characteristics among primary studies by determining if effect sizes vary among studies with different intervention characteristics. Intervention effectiveness can be linked to patient characteristics to provide evidence for patient-centered care. Moderator analyses often answer questions never posed by primary studies because neither multiple intervention characteristics nor populations are compared in single primary studies. Thus meta-analyses provide unique contributions to knowledge. Although meta-analysis is a powerful comparative effectiveness strategy, methodological challenges and limitations in primary research must be acknowledged to interpret findings. PMID:22789450

Can statistic adjustment of OR minimize the potential confounding bias for meta-analysis of case-control study? A secondary data analysis.

PubMed

Liu, Tianyi; Nie, Xiaolu; Wu, Zehao; Zhang, Ying; Feng, Guoshuang; Cai, Siyu; Lv, Yaqi; Peng, Xiaoxia

2017-12-29

Different confounder adjustment strategies were used to estimate odds ratios (ORs) in case-control study, i.e. how many confounders original studies adjusted and what the variables are. This secondary data analysis is aimed to detect whether there are potential biases caused by difference of confounding factor adjustment strategies in case-control study, and whether such bias would impact the summary effect size of meta-analysis. We included all meta-analyses that focused on the association between breast cancer and passive smoking among non-smoking women, as well as each original case-control studies included in these meta-analyses. The relative deviations (RDs) of each original study were calculated to detect how magnitude the adjustment would impact the estimation of ORs, compared with crude ORs. At the same time, a scatter diagram was sketched to describe the distribution of adjusted ORs with different number of adjusted confounders. Substantial inconsistency existed in meta-analysis of case-control studies, which would influence the precision of the summary effect size. First, mixed unadjusted and adjusted ORs were used to combine individual OR in majority of meta-analysis. Second, original studies with different adjustment strategies of confounders were combined, i.e. the number of adjusted confounders and different factors being adjusted in each original study. Third, adjustment did not make the effect size of original studies trend to constringency, which suggested that model fitting might have failed to correct the systematic error caused by confounding. The heterogeneity of confounder adjustment strategies in case-control studies may lead to further bias for summary effect size in meta-analyses, especially for weak or medium associations so that the direction of causal inference would be even reversed. Therefore, further methodological researches are needed, referring to the assessment of confounder adjustment strategies, as well as how to take this kind of bias into consideration when drawing conclusion based on summary estimation of meta-analyses.

Parental divorce, sibship size, family resources, and children's academic performance.

PubMed

Sun, Yongmin; Li, Yuanzhang

2009-09-01

Using data from 19,839 adolescents from the National Education Longitudinal Study, this study investigates whether the effects of parental divorce on adolescents' academic test performance vary by sibship size. Analyses show that the negative effect of divorce on adolescent performance attenuates as sibship size increases. On the other side of the interaction, the inverse relationship between sibship size and test performance is weaker in disrupted than in two-biological-parent families. Trends of such interactions are evident when sibship size is examined either as a continuous or a categorical measure. Finally, the observed interactions on adolescents' academic performance are completely explained by variations in parental financial, human, cultural, and social resources. In sum, this study underlines the importance of treating the effect of parental divorce as a variable and calls for more research to identify child and family features that may change the magnitude of such an effect.

Further Improvement of the RITS Code for Pulsed Neutron Bragg-edge Transmission Imaging

NASA Astrophysics Data System (ADS)

Sato, H.; Watanabe, K.; Kiyokawa, K.; Kiyanagi, R.; Hara, K. Y.; Kamiyama, T.; Furusaka, M.; Shinohara, T.; Kiyanagi, Y.

The RITS code is a unique and powerful tool for a whole Bragg-edge transmission spectrum fitting analysis. However, it has had two major problems. Therefore, we have proposed methods to overcome these problems. The first issue is the difference in the crystallite size values between the diffraction and the Bragg-edge analyses. We found the reason was a different definition of the crystal structure factor. It affects the crystallite size because the crystallite size is deduced from the primary extinction effect which depends on the crystal structure factor. As a result of algorithm change, crystallite sizes obtained by RITS drastically approached to crystallite sizes obtained by Rietveld analyses of diffraction data; from 155% to 110%. The second issue is correction of the effect of background neutrons scattered from a specimen. Through neutron transport simulation studies, we found that the background components consist of forward Bragg scattering, double backward Bragg scattering, and thermal diffuse scattering. RITS with the background correction function which was developed through the simulation studies could well reconstruct various simulated and experimental transmission spectra, but refined crystalline microstructural parameters were often distorted. Finally, it was recommended to reduce the background by improving experimental conditions.

Effect of wheat flour characteristics on sponge cake quality.

PubMed

Moiraghi, Malena; de la Hera, Esther; Pérez, Gabriela T; Gómez, Manuel

2013-02-01

To select the flour parameters that relate strongly to cake-making performance, in this study the relationship between sponge cake quality, solvent retention capacity (SRC) profile and flour physicochemical characteristics was investigated using 38 soft wheat samples of different origins. Particle size average, protein, damaged starch, water-soluble pentosans, total pentosans, SRC and pasting properties were analysed. Sponge cake volume and crumb texture were measured to evaluate cake quality. Cluster analysis was applied to assess differences in flour quality parameters among wheat lines based on the SRC profile. Cluster 1 showed significantly higher sponge cake volume and crumb softness, finer particle size and lower SRC sucrose, SRC carbonate, SRC water, damaged starch and protein content. Particle size, damaged starch, protein, thickening capacity and SRC parameters correlated negatively with sponge cake volume, while total pentosans and pasting temperature showed the opposite effect. The negative correlations between cake volume and SRC parameters along with the cluster analysis results indicated that flours with smaller particle size, lower absorption capacity and higher pasting temperature had better cake-making performance. Some simple analyses, such as SRC, particle size distribution and pasting properties, may help to choose flours suitable for cake making. Copyright © 2012 Society of Chemical Industry.

Meta-Analysis With Complex Research Designs: Dealing With Dependence From Multiple Measures and Multiple Group Comparisons

PubMed Central

Scammacca, Nancy; Roberts, Greg; Stuebing, Karla K.

2013-01-01

Previous research has shown that treating dependent effect sizes as independent inflates the variance of the mean effect size and introduces bias by giving studies with more effect sizes more weight in the meta-analysis. This article summarizes the different approaches to handling dependence that have been advocated by methodologists, some of which are more feasible to implement with education research studies than others. A case study using effect sizes from a recent meta-analysis of reading interventions is presented to compare the results obtained from different approaches to dealing with dependence. Overall, mean effect sizes and variance estimates were found to be similar, but estimates of indexes of heterogeneity varied. Meta-analysts are advised to explore the effect of the method of handling dependence on the heterogeneity estimates before conducting moderator analyses and to choose the approach to dependence that is best suited to their research question and their data set. PMID:25309002

The effect of grinding on the mechanical behavior of Y-TZP ceramics: A systematic review and meta-analyses.

PubMed

Pereira, G K R; Fraga, S; Montagner, A F; Soares, F Z M; Kleverlaan, C J; Valandro, L F

2016-10-01

The aim of this study was to systematically review the literature to assess the effect of grinding on the mechanical properties, structural stability and superficial characteristics of Y-TZP ceramics. The MEDLINE via PubMed and Web of Science (ISI - Web of Knowledge) electronic databases were searched with included peer-reviewed publications in English language and with no publication year limit. From 342 potentially eligible studies, 73 were selected for full-text analysis, 30 were included in the systematic review with 20 considered in the meta-analysis. Two reviewers independently selected the studies, extracted the data, and assessed the risk of bias. Statistical analyses were performed using RevMan 5.1, with random effects model, at a significance level of 0.05. A descriptive analysis considering phase transformation, Y-TZP grain size, Vickers hardness, residual stress and aging of all included studies were executed. Four outcomes were considered in the meta-analyses (factor: grinding x as-sintered) in global and subgroups analyses (grinding tool, grit-size and cooling) for flexural strength and roughness (Ra) data. A significant difference (p<0.05) was observed in the global analysis for strength, favoring as-sintered; subgroup analyses revealed that different parameters lead to different effects on strength. In the global analysis for roughness, a significant difference (p<0.05) was observed between conditions, favoring grinding; subgroup analyses revealed that different parameters also lead to different effects on roughness. High heterogeneity was found in some comparisons. Generally grinding promotes decrease in strength and increase in roughness of Y-TZP ceramics. However, the use of a grinding tool that allows greater accuracy of the movement (i.e. contra angle hand-pieces coupled to slowspeed turbines), small grit size (<50μm) and the use of plenty coolant seem to be the main factors to decrease the defect introduction and allow the occurrence of the toughening transformation mechanism, decreasing the risk of deleterious impact on Y-TZP mechanical properties. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of Coulomb interaction on chemical potential of metal film

NASA Astrophysics Data System (ADS)

Kostrobij, P. P.; Markovych, B. M.

2018-07-01

The chemical potential of a metal film within the jellium model taking into account the Coulomb interaction between electrons is calculated. The surface potential is modelled as the infinite rectangular potential well. The behaviour of the chemical potential as a function of the film thickness is studied, the quantum size effect for this quantity is analysed. It is shown that taking into account the Coulomb interaction leads to a significant decrease of the chemical potential and to an enhancement of the quantum size effect.

Effects of Morphological Family Size for Young Readers

ERIC Educational Resources Information Center

Perdijk, Kors; Schreuder, Robert; Baayen, R. Harald; Verhoeven, Ludo

2012-01-01

Dutch children, from the second and fourth grade of primary school, were each given a visual lexical decision test on 210 Dutch monomorphemic words. After removing words not recognized by a majority of the younger group, (lexical) decisions were analysed by mixed-model regression methods to see whether morphological Family Size influenced decision…

Consonant Inventories in the Spontaneous Speech of Young Children: A Bootstrapping Procedure

ERIC Educational Resources Information Center

Van Severen, Lieve; Van Den Berg, Renate; Molemans, Inge; Gillis, Steven

2012-01-01

Consonant inventories are commonly drawn to assess the phonological acquisition of toddlers. However, the spontaneous speech data that are analysed often vary substantially in size and composition. Consequently, comparisons between children and across studies are fundamentally hampered. This study aims to examine the effect of sample size on the…

Development of a local size hierarchy causes regular spacing of trees in an even-aged Abies forest: analyses using spatial autocorrelation and the mark correlation function.

PubMed

Suzuki, Satoshi N; Kachi, Naoki; Suzuki, Jun-Ichirou

2008-09-01

During the development of an even-aged plant population, the spatial distribution of individuals often changes from a clumped pattern to a random or regular one. The development of local size hierarchies in an Abies forest was analysed for a period of 47 years following a large disturbance in 1959. In 1980 all trees in an 8 x 8 m plot were mapped and their height growth after the disturbance was estimated. Their mortality and growth were then recorded at 1- to 4-year intervals between 1980 and 2006. Spatial distribution patterns of trees were analysed by the pair correlation function. Spatial correlations between tree heights were analysed with a spatial autocorrelation function and the mark correlation function. The mark correlation function was able to detect a local size hierarchy that could not be detected by the spatial autocorrelation function alone. The small-scale spatial distribution pattern of trees changed from clumped to slightly regular during the 47 years. Mortality occurred in a density-dependent manner, which resulted in regular spacing between trees after 1980. The spatial autocorrelation and mark correlation functions revealed the existence of tree patches consisting of large trees at the initial stage. Development of a local size hierarchy was detected within the first decade after the disturbance, although the spatial autocorrelation was not negative. Local size hierarchies that developed persisted until 2006, and the spatial autocorrelation became negative at later stages (after about 40 years). This is the first study to detect local size hierarchies as a prelude to regular spacing using the mark correlation function. The results confirm that use of the mark correlation function together with the spatial autocorrelation function is an effective tool to analyse the development of a local size hierarchy of trees in a forest.

The influence of genetic and environmental factors in estimations of current body size, desired body size, and body dissatisfaction.

PubMed

Wade, T D; Bulik, C M; Heath, A C; Martin, N G; Eaves, L J

2001-08-01

The objective was to investigate the genetic epidemiology of figural stimuli. Standard figural stimuli were available from 5,325 complete twin pairs: 1,751 (32.9%) were monozygotic females, 1,068 (20.1%) were dizygotic females, 752 (14.1%) were monozygotic males, 495 (9.3%) were dizygotic males, and 1,259 (23.6%) were dizygotic male-female pairs. Univariate twin analyses were used to examine the influences on the individual variation in current body size and ideal body size. These data were analysed separately for men and women in each of five age groups. A factorial analysis of variance, with polychoric correlations between twin pairs as the dependent variable, and age, sex, zygosity, and the three interaction terms (age x sex, age x zygosity, sex x zygosity) as independent variables, was used to examine trends across the whole data set. Results showed genetic influences had the largest impact on the individual variation in current body size measures, whereas non-shared environmental influences were associated with the majority of individual variation in ideal body size. There was a significant main effect of zygosity (heritability) in predicting polychoric correlations for current body size and body dissatisfaction. There was a significant main effect of gender and zygosity in predicting ideal body size, with a gender x zygosity interaction. In common with BMI, heritability is important in influencing the estimation of current body size. Selection of desired body size for both men and women is more strongly influenced by environmental factors.

Effects of a Web-Based Tailored Multiple-Lifestyle Intervention for Adults: A Two-Year Randomized Controlled Trial Comparing Sequential and Simultaneous Delivery Modes

PubMed Central

Kremers, Stef PJ; Vandelanotte, Corneel; van Adrichem, Mathieu JG; Schneider, Francine; Candel, Math JJM; de Vries, Hein

2014-01-01

Background Web-based computer-tailored interventions for multiple health behaviors can have a significant public health impact. Yet, few randomized controlled trials have tested this assumption. Objective The objective of this paper was to test the effects of a sequential and simultaneous Web-based tailored intervention on multiple lifestyle behaviors. Methods A randomized controlled trial was conducted with 3 tailoring conditions (ie, sequential, simultaneous, and control conditions) in the Netherlands in 2009-2012. Follow-up measurements took place after 12 and 24 months. The intervention content was based on the I-Change model. In a health risk appraisal, all respondents (N=5055) received feedback on their lifestyle behaviors that indicated whether they complied with the Dutch guidelines for physical activity, vegetable consumption, fruit consumption, alcohol intake, and smoking. Participants in the sequential (n=1736) and simultaneous (n=1638) conditions received tailored motivational feedback to change unhealthy behaviors one at a time (sequential) or all at the same time (simultaneous). Mixed model analyses were performed as primary analyses; regression analyses were done as sensitivity analyses. An overall risk score was used as outcome measure, then effects on the 5 individual lifestyle behaviors were assessed and a process evaluation was performed regarding exposure to and appreciation of the intervention. Results Both tailoring strategies were associated with small self-reported behavioral changes. The sequential condition had the most significant effects compared to the control condition after 12 months (T1, effect size=0.28). After 24 months (T2), the simultaneous condition was most effective (effect size=0.18). All 5 individual lifestyle behaviors changed over time, but few effects differed significantly between the conditions. At both follow-ups, the sequential condition had significant changes in smoking abstinence compared to the simultaneous condition (T1 effect size=0.31; T2 effect size=0.41). The sequential condition was more effective in decreasing alcohol consumption than the control condition at 24 months (effect size=0.27). Change was predicted by the amount of exposure to the intervention (total visiting time: beta=–.06; P=.01; total number of visits: beta=–.11; P<.001). Both interventions were appreciated well by respondents without significant differences between conditions. Conclusions Although evidence was found for the effectiveness of both programs, no simple conclusive finding could be drawn about which intervention mode was more effective. The best kind of intervention may depend on the behavior that is targeted or on personal preferences and motivation. Further research is needed to identify moderators of intervention effectiveness. The results need to be interpreted in view of the high and selective dropout rates, multiple comparisons, and modest effect sizes. However, a large number of people were reached at low cost and behavioral change was achieved after 2 years. Trial Registration Nederlands Trial Register: NTR 2168; http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=2168 (Archived by WebCite at http://www.webcitation.org/6MbUqttYB). PMID:24472854

Reciprocity explains food sharing in humans and other primates independent of kin selection and tolerated scrounging: a phylogenetic meta-analysis.

PubMed

Jaeggi, Adrian V; Gurven, Michael

2013-10-07

Helping, i.e. behaviour increasing the fitness of others, can evolve when directed towards kin or reciprocating partners. These predictions have been tested in the context of food sharing both in human foragers and non-human primates. Here, we performed quantitative meta-analyses on 32 independent study populations to (i) test for overall effects of reciprocity on food sharing while controlling for alternative explanations, methodological biases, publication bias and phylogeny and (ii) compare the relative effects of reciprocity, kinship and tolerated scrounging, i.e. sharing owing to costs imposed by others. We found a significant overall weighted effect size for reciprocity of r = 0.20-0.48 for the most and least conservative measure, respectively. Effect sizes did not differ between humans and other primates, although there were species differences in in-kind reciprocity and trade. The relative effect of reciprocity in sharing was similar to those of kinship and tolerated scrounging. These results indicate a significant independent contribution of reciprocity to human and primate helping behaviour. Furthermore, similar effect sizes in humans and primates speak against cognitive constraints on reciprocity. This study is the first to use meta-analyses to quantify these effects on human helping and to directly compare humans and other primates.

Reciprocity explains food sharing in humans and other primates independent of kin selection and tolerated scrounging: a phylogenetic meta-analysis

PubMed Central

Jaeggi, Adrian V.; Gurven, Michael

2013-01-01

Helping, i.e. behaviour increasing the fitness of others, can evolve when directed towards kin or reciprocating partners. These predictions have been tested in the context of food sharing both in human foragers and non-human primates. Here, we performed quantitative meta-analyses on 32 independent study populations to (i) test for overall effects of reciprocity on food sharing while controlling for alternative explanations, methodological biases, publication bias and phylogeny and (ii) compare the relative effects of reciprocity, kinship and tolerated scrounging, i.e. sharing owing to costs imposed by others. We found a significant overall weighted effect size for reciprocity of r = 0.20–0.48 for the most and least conservative measure, respectively. Effect sizes did not differ between humans and other primates, although there were species differences in in-kind reciprocity and trade. The relative effect of reciprocity in sharing was similar to those of kinship and tolerated scrounging. These results indicate a significant independent contribution of reciprocity to human and primate helping behaviour. Furthermore, similar effect sizes in humans and primates speak against cognitive constraints on reciprocity. This study is the first to use meta-analyses to quantify these effects on human helping and to directly compare humans and other primates. PMID:23945693

Life-span development of self-esteem and its effects on important life outcomes.

PubMed

Orth, Ulrich; Robins, Richard W; Widaman, Keith F

2012-06-01

We examined the life-span development of self-esteem and tested whether self-esteem influences the development of important life outcomes, including relationship satisfaction, job satisfaction, occupational status, salary, positive and negative affect, depression, and physical health. Data came from the Longitudinal Study of Generations. Analyses were based on 5 assessments across a 12-year period of a sample of 1,824 individuals ages 16 to 97 years. First, growth curve analyses indicated that self-esteem increases from adolescence to middle adulthood, reaches a peak at about age 50 years, and then decreases in old age. Second, cross-lagged regression analyses indicated that self-esteem is best modeled as a cause rather than a consequence of life outcomes. Third, growth curve analyses, with self-esteem as a time-varying covariate, suggested that self-esteem has medium-sized effects on life-span trajectories of affect and depression, small to medium-sized effects on trajectories of relationship and job satisfaction, a very small effect on the trajectory of health, and no effect on the trajectory of occupational status. These findings replicated across 4 generations of participants--children, parents, grandparents, and their great-grandparents. Together, the results suggest that self-esteem has a significant prospective impact on real-world life experiences and that high and low self-esteem are not mere epiphenomena of success and failure in important life domains. 2012 APA, all rights reserved

The clinical impact of a brief transition programme for young people with juvenile idiopathic arthritis: results of the DON'T RETARD project.

PubMed

Hilderson, Deborah; Moons, Philip; Van der Elst, Kristien; Luyckx, Koen; Wouters, Carine; Westhovens, René

2016-01-01

To investigate the clinical impact of a brief transition programme for young people with JIA. The Devices for Optimization of Transfer and Transition of Adolescents with Rheumatic Disorders (DON'T RETARD) project is a mixed method project in which we first conducted a quasi-experimental study employing a one-group pre-test-post-test with a non-equivalent post-test-only comparison group design. In this quantitative study, we investigated clinical outcomes in patients with JIA and their parents who participated in the transition programme (longitudinal analyses). The post-test scores of this intervention group were compared with those of patients who received usual care (comparative analyses). Second, a qualitative study was conducted to explore the experiences of adolescents with JIA and their parents regarding their participation in the transition programme. The primary hypothesis of improved physical (effect size 0.11), psychosocial (effect size 0.46) and rheumatic-specific health status (effect size ranging from 0.21 to 0.33), was confirmed. With respect to the secondary outcomes, improved quality of life (effect size 0.51) and an optimized parenting climate (effect size ranging from 0.21 to 0.28) were observed. No effect was measured in medication adherence (odds ratio 1.46). Implementation of a transition programme as a brief intervention can improve the perceived health and quality of life of adolescents with JIA during the transition process, as well as the parenting behaviours of their parents. Based on the present study, a randomized controlled trial can be designed to evaluate the effectiveness of the transition programme. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Effect Size Analyses of Souvenaid in Patients with Alzheimer’s Disease

PubMed Central

Cummings, Jeffrey; Scheltens, Philip; McKeith, Ian; Blesa, Rafael; Harrison, John E.; Bertolucci, Paulo H.F.; Rockwood, Kenneth; Wilkinson, David; Wijker, Wouter; Bennett, David A.; Shah, Raj C.

2016-01-01

Background: Souvenaid® (uridine monophosphate, docosahexaenoic acid, eicosapentaenoic acid, choline, phospholipids, folic acid, vitamins B12, B6, C, and E, and selenium), was developed to support the formation and function of neuronal membranes. Objective: To determine effect sizes observed in clinical trials of Souvenaid and to calculate the number needed to treat to show benefit or harm. Methods: Data from all three reported randomized controlled trials of Souvenaid in Alzheimer’s disease (AD) dementia (Souvenir I, Souvenir II, and S-Connect) and an open-label extension study were included in analyses of effect size for cognitive, functional, and behavioral outcomes. Effect size was determined by calculating Cohen’s d statistic (or Cramér’s V method for nominal data), number needed to treat and number needed to harm. Statistical calculations were performed for the intent-to-treat populations. Results: In patients with mild AD, effect sizes were 0.21 (95% confidence intervals: –0.06, 0.49) for the primary outcome in Souvenir II (neuropsychological test battery memory z-score) and 0.20 (0.10, 0.34) for the co-primary outcome of Souvenir I (Wechsler memory scale delayed recall). No effect was shown on cognition in patients with mild-to-moderate AD (S-Connect). The number needed to treat (6 and 21 for Souvenir I and II, respectively) and high number needed to harm values indicate a favorable harm:benefit ratio for Souvenaid versus control in patients with mild AD. Conclusions: The favorable safety profile and impact on outcome measures converge to corroborate the putative mode of action and demonstrate that Souvenaid can achieve clinically detectable effects in patients with early AD. PMID:27767993

Temperature-dependent body size effects determine population responses to climate warming.

PubMed

Lindmark, Max; Huss, Magnus; Ohlberger, Jan; Gårdmark, Anna

2018-02-01

Current understanding of animal population responses to rising temperatures is based on the assumption that biological rates such as metabolism, which governs fundamental ecological processes, scale independently with body size and temperature, despite empirical evidence for interactive effects. Here, we investigate the consequences of interactive temperature- and size scaling of vital rates for the dynamics of populations experiencing warming using a stage-structured consumer-resource model. We show that interactive scaling alters population and stage-specific responses to rising temperatures, such that warming can induce shifts in population regulation and stage-structure, influence community structure and govern population responses to mortality. Analysing experimental data for 20 fish species, we found size-temperature interactions in intraspecific scaling of metabolic rate to be common. Given the evidence for size-temperature interactions and the ubiquity of size structure in animal populations, we argue that accounting for size-specific temperature effects is pivotal for understanding how warming affects animal populations and communities. © 2017 The Authors. Ecology Letters published by CNRS and John Wiley & Sons Ltd.

Impact of vaccine herd-protection effects in cost-effectiveness analyses of childhood vaccinations. A quantitative comparative analysis.

PubMed

Holubar, Marisa; Stavroulakis, Maria Christina; Maldonado, Yvonne; Ioannidis, John P A; Contopoulos-Ioannidis, Despina

2017-01-01

Inclusion of vaccine herd-protection effects in cost-effectiveness analyses (CEAs) can impact the CEAs-conclusions. However, empirical epidemiologic data on the size of herd-protection effects from original studies are limited. We performed a quantitative comparative analysis of the impact of herd-protection effects in CEAs for four childhood vaccinations (pneumococcal, meningococcal, rotavirus and influenza). We considered CEAs reporting incremental-cost-effectiveness-ratios (ICERs) (per quality-adjusted-life-years [QALY] gained; per life-years [LY] gained or per disability-adjusted-life-years [DALY] avoided), both with and without herd protection, while keeping all other model parameters stable. We calculated the size of the ICER-differences without vs with-herd-protection and estimated how often inclusion of herd-protection led to crossing of the cost-effectiveness threshold (of an assumed societal-willingness-to-pay) of $50,000 for more-developed countries or X3GDP/capita (WHO-threshold) for less-developed countries. We identified 35 CEA studies (20 pneumococcal, 4 meningococcal, 8 rotavirus and 3 influenza vaccines) with 99 ICER-analyses (55 per-QALY, 27 per-LY and 17 per-DALY). The median ICER-absolute differences per QALY, LY and DALY (without minus with herd-protection) were $15,620 (IQR: $877 to $48,376); $54,871 (IQR: $787 to $115,026) and $49 (IQR: $15 to $1,636) respectively. When the target-vaccination strategy was not cost-saving without herd-protection, inclusion of herd-protection always resulted in more favorable results. In CEAs that had ICERs above the cost-effectiveness threshold without herd-protection, inclusion of herd-protection led to crossing of that threshold in 45% of the cases. This impacted only CEAs for more developed countries, as all but one CEAs for less developed countries had ICERs below the WHO-cost-effectiveness threshold even without herd-protection. In several analyses, recommendation for the adoption of the target vaccination strategy depended on the inclusion of the herd protection effect. Inclusion of herd-protection effects in CEAs had a substantial impact in the estimated ICERs and made target-vaccination strategies more attractive options in almost half of the cases where ICERs were above the societal-willingness to pay threshold without herd-protection. More empirical epidemiologic data are needed to determine the size of herd-protection effects across diverse settings and also the size of negative vaccine effects, e.g. from serotype substitution.

Impact of vaccine herd-protection effects in cost-effectiveness analyses of childhood vaccinations. A quantitative comparative analysis

PubMed Central

Maldonado, Yvonne; Ioannidis, John P. A.; Contopoulos-Ioannidis, Despina

2017-01-01

Background Inclusion of vaccine herd-protection effects in cost-effectiveness analyses (CEAs) can impact the CEAs-conclusions. However, empirical epidemiologic data on the size of herd-protection effects from original studies are limited. Methods We performed a quantitative comparative analysis of the impact of herd-protection effects in CEAs for four childhood vaccinations (pneumococcal, meningococcal, rotavirus and influenza). We considered CEAs reporting incremental-cost-effectiveness-ratios (ICERs) (per quality-adjusted-life-years [QALY] gained; per life-years [LY] gained or per disability-adjusted-life-years [DALY] avoided), both with and without herd protection, while keeping all other model parameters stable. We calculated the size of the ICER-differences without vs with-herd-protection and estimated how often inclusion of herd-protection led to crossing of the cost-effectiveness threshold (of an assumed societal-willingness-to-pay) of $50,000 for more-developed countries or X3GDP/capita (WHO-threshold) for less-developed countries. Results We identified 35 CEA studies (20 pneumococcal, 4 meningococcal, 8 rotavirus and 3 influenza vaccines) with 99 ICER-analyses (55 per-QALY, 27 per-LY and 17 per-DALY). The median ICER-absolute differences per QALY, LY and DALY (without minus with herd-protection) were $15,620 (IQR: $877 to $48,376); $54,871 (IQR: $787 to $115,026) and $49 (IQR: $15 to $1,636) respectively. When the target-vaccination strategy was not cost-saving without herd-protection, inclusion of herd-protection always resulted in more favorable results. In CEAs that had ICERs above the cost-effectiveness threshold without herd-protection, inclusion of herd-protection led to crossing of that threshold in 45% of the cases. This impacted only CEAs for more developed countries, as all but one CEAs for less developed countries had ICERs below the WHO-cost-effectiveness threshold even without herd-protection. In several analyses, recommendation for the adoption of the target vaccination strategy depended on the inclusion of the herd protection effect. Conclusions Inclusion of herd-protection effects in CEAs had a substantial impact in the estimated ICERs and made target-vaccination strategies more attractive options in almost half of the cases where ICERs were above the societal-willingness to pay threshold without herd-protection. More empirical epidemiologic data are needed to determine the size of herd-protection effects across diverse settings and also the size of negative vaccine effects, e.g. from serotype substitution. PMID:28249046

Effect Size Calculations and Single Subject Designs

ERIC Educational Resources Information Center

Olive, Melissa L.; Smith, Benjamin W.

2005-01-01

This study compared visual analyses with five alternative methods for assessing the magnitude of effect with single subject designs. Each method was successful in detecting intervention effect. When rank ordered, each method was consistent in identifying the participants with the largest effect. We recommend the use of the standard mean difference…

The Validity of Conscientiousness Is Overestimated in the Prediction of Job Performance.

PubMed

Kepes, Sven; McDaniel, Michael A

2015-01-01

Sensitivity analyses refer to investigations of the degree to which the results of a meta-analysis remain stable when conditions of the data or the analysis change. To the extent that results remain stable, one can refer to them as robust. Sensitivity analyses are rarely conducted in the organizational science literature. Despite conscientiousness being a valued predictor in employment selection, sensitivity analyses have not been conducted with respect to meta-analytic estimates of the correlation (i.e., validity) between conscientiousness and job performance. To address this deficiency, we reanalyzed the largest collection of conscientiousness validity data in the personnel selection literature and conducted a variety of sensitivity analyses. Publication bias analyses demonstrated that the validity of conscientiousness is moderately overestimated (by around 30%; a correlation difference of about .06). The misestimation of the validity appears to be due primarily to suppression of small effects sizes in the journal literature. These inflated validity estimates result in an overestimate of the dollar utility of personnel selection by millions of dollars and should be of considerable concern for organizations. The fields of management and applied psychology seldom conduct sensitivity analyses. Through the use of sensitivity analyses, this paper documents that the existing literature overestimates the validity of conscientiousness in the prediction of job performance. Our data show that effect sizes from journal articles are largely responsible for this overestimation.

The Validity of Conscientiousness Is Overestimated in the Prediction of Job Performance

PubMed Central

2015-01-01

Introduction Sensitivity analyses refer to investigations of the degree to which the results of a meta-analysis remain stable when conditions of the data or the analysis change. To the extent that results remain stable, one can refer to them as robust. Sensitivity analyses are rarely conducted in the organizational science literature. Despite conscientiousness being a valued predictor in employment selection, sensitivity analyses have not been conducted with respect to meta-analytic estimates of the correlation (i.e., validity) between conscientiousness and job performance. Methods To address this deficiency, we reanalyzed the largest collection of conscientiousness validity data in the personnel selection literature and conducted a variety of sensitivity analyses. Results Publication bias analyses demonstrated that the validity of conscientiousness is moderately overestimated (by around 30%; a correlation difference of about .06). The misestimation of the validity appears to be due primarily to suppression of small effects sizes in the journal literature. These inflated validity estimates result in an overestimate of the dollar utility of personnel selection by millions of dollars and should be of considerable concern for organizations. Conclusion The fields of management and applied psychology seldom conduct sensitivity analyses. Through the use of sensitivity analyses, this paper documents that the existing literature overestimates the validity of conscientiousness in the prediction of job performance. Our data show that effect sizes from journal articles are largely responsible for this overestimation. PMID:26517553

Model-size reduction for the buckling and vibration analyses of anisotropic panels

NASA Technical Reports Server (NTRS)

Noor, A. K.; Whitworth, S. L.

1986-01-01

A computational procedure is presented for reducing the size of the model used in the buckling and vibration analyses of symmetric anisotropic panels to that of the corresponding orthotropic model. The key elements of the procedure are the application of an operator splitting technique through the decomposition of the material stiffness matrix of the panel into the sum of orthotropic and nonorthotropic (anisotropic) parts and the use of a reduction method through successive application of the finite element method and the classical Rayleigh-Ritz technique. The effectiveness of the procedure is demonstrated by numerical examples.

Assessing the internal consistency of the event-related potential: An example analysis.

PubMed

Thigpen, Nina N; Kappenman, Emily S; Keil, Andreas

2017-01-01

ERPs are widely and increasingly used to address questions in psychophysiological research. As discussed in this special issue, a renewed focus on questions of reliability and stability marks the need for intuitive, quantitative descriptors that allow researchers to communicate the robustness of ERP measures used in a given study. This report argues that well-established indices of internal consistency and effect size meet this need and can be easily extracted from most ERP datasets, as demonstrated with example analyses using a representative dataset from a feature-based visual selective attention task. We demonstrate how to measure the internal consistency of three aspects commonly considered in ERP studies: voltage measurements for specific time ranges at selected sensors, voltage dynamics across all time points of the ERP waveform, and the distribution of voltages across the scalp. We illustrate methods for quantifying the robustness of experimental condition differences, by calculating effect size for different indices derived from the ERP. The number of trials contributing to the ERP waveform was manipulated to examine the relationship between signal-to-noise ratio (SNR), internal consistency, and effect size. In the present example dataset, satisfactory consistency (Cronbach's alpha > 0.7) of individual voltage measurements was reached at lower trial counts than were required to reach satisfactory effect sizes for differences between experimental conditions. Comparing different metrics of robustness, we conclude that the internal consistency and effect size of ERP findings greatly depend on the quantification strategy, the comparisons and analyses performed, and the SNR. © 2016 Society for Psychophysiological Research.

Assessing the internal consistency of the event-related potential: An example analysis

PubMed Central

Thigpen, Nina; Kappenman, Emily; Keil, Andreas

2017-01-01

Event-related potentials (ERPs) are widely and increasingly used to address questions in Psychophysiological research. As discussed in this special issue, a renewed focus on questions of reliability and stability marks the need for intuitive, quantitative descriptors that allow researchers to communicate the robustness of ERP measures used in a given study. This report argues that well-established indices of internal consistency and effect size meet this need and can be easily extracted from most ERP data sets, as demonstrated with example analyses using a representative data set from a feature-based visual selective attention task. We demonstrate how to measure the internal consistency of three aspects commonly considered in ERP studies: Voltage measurements for specific time ranges at selected sensors, voltage dynamics across all time points of the ERP waveform, and the distribution of voltages across the scalp. We illustrate methods for quantifying the robustness of experimental condition differences, by calculating effect size for different indices derived from the ERP. The number of trials contributing to the ERP waveform was manipulated to examine the relationship between signal-to-noise ratio, internal consistency, and effect size. In the present example data set, satisfactory consistency (Cronbach’s alpha > 0.7) of individual voltage measurements was reached at lower trial counts than were required to reach satisfactory effect sizes for differences between experimental conditions. Comparing different metrics of robustness, we conclude that the SNR, internal consistency, and effect size of ERP findings greatly depend on the quantification strategy, the comparisons and analyses performed, and the signal-to-noise ratio. PMID:28000264

A Regression Framework for Effect Size Assessments in Longitudinal Modeling of Group Differences

PubMed Central

Feingold, Alan

2013-01-01

The use of growth modeling analysis (GMA)--particularly multilevel analysis and latent growth modeling--to test the significance of intervention effects has increased exponentially in prevention science, clinical psychology, and psychiatry over the past 15 years. Model-based effect sizes for differences in means between two independent groups in GMA can be expressed in the same metric (Cohen’s d) commonly used in classical analysis and meta-analysis. This article first reviews conceptual issues regarding calculation of d for findings from GMA and then introduces an integrative framework for effect size assessments that subsumes GMA. The new approach uses the structure of the linear regression model, from which effect sizes for findings from diverse cross-sectional and longitudinal analyses can be calculated with familiar statistics, such as the regression coefficient, the standard deviation of the dependent measure, and study duration. PMID:23956615

Individual differences in risk taking and endogeneous levels of testosterone, estradiol, and cortisol: A systematic literature search and three independent meta-analyses.

PubMed

Kurath, Jennifer; Mata, Rui

2018-05-03

Hormonal levels have been hypothesized to serve as proximal biological mechanisms underlying individual differences in risk taking. We conducted a systematic literature search and independent meta-analyses to assess the link between endogenous testosterone, estradiol, and cortisol levels and risk-taking related constructs (i.e., risk-taking propensity, impulsivity, sensation seeking, novelty seeking). We found small correlations between risk-taking constructs and testosterone (r = 0.12, 95% CI = 0.08, 0.16, 108 effect sizes, k = 49, N = 9112) as well as estradiol (r = 0.10, 95% CI = 0.02, 0.18, 48 effect sizes, k = 17, N = 2900), but not cortisol (r = -0.01, 95% CI = -0.11, 0.09, 60 effect sizes, k = 27, N = 3880). Overall, these results suggest a biological foundation for individual differences in risk taking. We point out some limitations of past studies and make recommendations for future work investigating the hormonal basis of individual differences in risk taking. Copyright © 2018 Elsevier Ltd. All rights reserved.

Meta-analyses of Theory use in Medication Adherence Intervention Research

PubMed Central

Conn, Vicki S.; Enriquez, Maithe; Ruppar, Todd M.; Chan, Keith C.

2016-01-01

Objective This systematic review applied meta-analytic procedures to integrate primary research that examined theory- or model-linked medication adherence interventions. Methods Extensive literature searching strategies were used to locate trials testing interventions with medication adherence behavior outcomes measured by electronic event monitoring, pharmacy refills, pill counts, and self-reports. Random-effects model analysis was used to calculate standardized mean difference effect sizes for medication adherence outcomes. Results Codable data were extracted from 146 comparisons with 19,348 participants. The most common theories and models were social cognitive theory and motivational interviewing. The overall weighted effect size for all interventions comparing treatment and control participants was 0.294. The effect size for interventions based on single-theories was 0.323 and for multiple-theory interventions was 0.214. Effect sizes for individual theories and models ranged from 0.041 to 0.447. The largest effect sizes were for interventions based on the health belief model (0.477) and adult learning theory (0.443). The smallest effect sizes were for interventions based on PRECEDE (0.041) and self-regulation (0.118). Conclusion These findings suggest that theory- and model-linked interventions have a significant but modest effect on medication adherence outcomes. PMID:26931748

Practical Effects of Classwide Mathematics Intervention

ERIC Educational Resources Information Center

VanDerHeyden, Amanda M.; Codding, Robin S.

2015-01-01

The current article presents additional analyses of a classwide mathematics intervention, from a previously reported randomized controlled trial, to offer new information about the treatment and to demonstrate the utility of different types of effect sizes. Multilevel modeling was used to examine treatment effects by race, sex, socioeconomic…

Heterogeneous effects of market integration on sub-adult body size and nutritional status among the Shuar of Amazonian Ecuador.

PubMed

Urlacher, Samuel S; Liebert, Melissa A; Josh Snodgrass, J; Blackwell, Aaron D; Cepon-Robins, Tara J; Gildner, Theresa E; Madimenos, Felicia C; Amir, Dorsa; Bribiescas, Richard G; Sugiyama, Lawrence S

2016-07-01

Market integration (MI)-increasing production for and consumption from a market-based economy-is drastically altering traditional ways of life and environmental conditions among indigenous Amazonian peoples. The effects of MI on the biology and health of Amazonian children and adolescents, however, remain unclear. This study examines the impact of MI on sub-adult body size and nutritional status at the population, regional and household levels among the Shuar of Amazonian Ecuador. Anthropometric data were collected between 2005-2014 from 2164 Shuar (aged 2-19 years) living in two geographic regions differing in general degree of MI. High-resolution household economic, lifestyle and dietary data were collected from a sub-sample of 631 participants. Analyses were performed to investigate relationships between body size and year of data collection, region and specific aspects of household MI. Results from temporal and regional analyses suggest that MI has a significant and overall positive impact on Shuar body size and nutritional status. However, household-level results exhibit nuanced and heterogeneous specific effects of MI underlying these overarching relationships. This study provides novel insight into the complex socio-ecological pathways linking MI, physical growth and health among the Shuar and other indigenous Amazonian populations.

Heterogeneous effects of market integration on subadult body size and nutritional status among the Shuar of Amazonian Ecuador

PubMed Central

Urlacher, Samuel S.; Liebert, Melissa A.; Snodgrass, J. Josh; Blackwell, Aaron D.; Cepon-Robins, Tara J.; Gildner, Theresa E.; Madimenos, Felicia C.; Amir, Dorsa; Bribiescas, Richard G.; Sugiyama, Lawrence S.

2016-01-01

Background Market integration (MI) – increasing production for and consumption from a market-based economy – is drastically altering traditional ways of life and environmental conditions among indigenous Amazonian peoples. The effects of MI on the biology and health of Amazonian children and adolescents, however, remain unclear. Aim This study examines the impact of MI on subadult body size and nutritional status at the population, regional, and household levels among the Shuar of Amazonian Ecuador. Subjects and Methods Anthropometric data were collected between 2005 and 2014 from 2,164 Shuar (age 2-19 years) living in two geographic regions differing in general degree of MI. High-resolution household economic, lifestyle, and dietary data were collected from a subsample of 631 participants. Analyses were performed to investigate relationships between body size and year of data collection, region, and specific aspects of household MI. Results Results from temporal and regional analyses suggest that MI has a significant and overall positive impact on Shuar body size and nutritional status. However, household-level results exhibit nuanced and heterogeneous specific effects of MI underlying these overarching relationships. Conclusion This study provides novel insight into the complex socio-ecological pathways linking MI, physical growth, and health among the Shuar and other indigenous Amazonian populations. PMID:27230632

Effect of anti-smoking health education on infant size at birth: a randomized controlled trial.

PubMed

MacArthur, C; Newton, J R; Knox, E G

1987-04-01

The effects of anti-smoking health education during pregnancy on smoking behaviour and the subsequent infant's size at birth were investigated in a controlled trial. It was found that the planned educational intervention was incompletely carried out and was given more effectively to primigravidae in whom subsequent reduction of smoking was more evident. The effects of educative intervention on size at birth were therefore analysed for first and later pregnancies separately. The differences in birthweight and length between the intervention and control groups were concentrated almost entirely among the first born infants who were 68 g heavier and 0.75 cm longer in the intervention group than the first born infants in the control group.

Long-distance plant dispersal to North Atlantic islands: colonization routes and founder effect.

PubMed

Alsos, Inger Greve; Ehrich, Dorothee; Eidesen, Pernille Bronken; Solstad, Heidi; Westergaard, Kristine Bakke; Schönswetter, Peter; Tribsch, Andreas; Birkeland, Siri; Elven, Reidar; Brochmann, Christian

2015-04-15

Long-distance dispersal (LDD) processes influence the founder effect on islands. We use genetic data for 25 Atlantic species and similarities among regional floras to analyse colonization, and test whether the genetic founder effect on five islands is associated with dispersal distance, island size and species traits. Most species colonized postglacially via multiple dispersal events from several source regions situated 280 to >3000 km away, and often not from the closest ones. A strong founder effect was observed for insect-pollinated mixed maters, and it increased with dispersal distance and decreased with island size in accordance with the theory of island biogeography. Only a minor founder effect was observed for wind-pollinated outcrossing species. Colonization patterns were largely congruent, indicating that despite the importance of stochasticity, LDD is mainly determined by common factors, probably dispersal vectors. Our findings caution against a priori assuming a single, close source region in biogeographic analyses. Published by Oxford University Press on behalf of the Annals of Botany Company.

Influence of control group on effect size in trials of acupuncture for chronic pain: a secondary analysis of an individual patient data meta-analysis.

PubMed

MacPherson, Hugh; Vertosick, Emily; Lewith, George; Linde, Klaus; Sherman, Karen J; Witt, Claudia M; Vickers, Andrew J

2014-01-01

In a recent individual patient data meta-analysis, acupuncture was found to be superior to both sham and non-sham controls in patients with chronic pain. In this paper we identify variations in types of sham and non-sham controls used and analyze their impact on the effect size of acupuncture. Based on literature searches of acupuncture trials involving patients with headache and migraine, osteoarthritis, and back, neck and shoulder pain, 29 trials met inclusion criteria, 20 involving sham controls (n = 5,230) and 18 non-sham controls (n = 14,597). For sham controls, we analysed non-needle sham, penetrating sham needles and non-penetrating sham needles. For non-sham controls, we analysed non-specified routine care and protocol-guided care. Using meta-regression we explored impact of choice of control on effect of acupuncture. Acupuncture was significantly superior to all categories of control group. For trials that used penetrating needles for sham control, acupuncture had smaller effect sizes than for trials with non-penetrating sham or sham control without needles. The difference in effect size was -0.45 (95% C.I. -0.78, -0.12; p = 0.007), or -0.19 (95% C.I. -0.39, 0.01; p = 0.058) after exclusion of outlying studies showing very large effects of acupuncture. In trials with non-sham controls, larger effect sizes associated with acupuncture vs. non-specified routine care than vs. protocol-guided care. Although the difference in effect size was large (0.26), it was not significant with a wide confidence interval (95% C.I. -0.05, 0.57, p = 0.1). Acupuncture is significantly superior to control irrespective of the subtype of control. While the choice of control should be driven by the study question, our findings can help inform study design in acupuncture, particularly with respect to sample size. Penetrating needles appear to have important physiologic activity. We recommend that this type of sham be avoided.

The relationship between persuasive technology principles, adherence and effect of web-Based interventions for mental health: A meta-analysis.

PubMed

Wildeboer, Gina; Kelders, Saskia M; van Gemert-Pijnen, Julia E W C

2016-12-01

Research has shown that web-based interventions concerning mental health can be effective, although there is a broad range in effect sizes. Why some interventions are more effective than others is not clear. Persuasive technology is one of the aspects which has a positive influence on changing attitude and/or behavior, and can contribute to better outcomes. According to the Persuasive Systems Design Model there are various principles that can be deployed. It is unknown whether the number and combinations of principles used in a web-based intervention affect the effectiveness. Another issue in web-based interventions is adherence. Little is known about the relationship of adherence on the effectiveness of web-based interventions. This study examines whether there is a relationship between the number and combinations of persuasive technology principles used in web-based interventions and the effectiveness. Also the influence of adherence on effectiveness of web-based interventions is investigated. This study elaborates on the systematic review by [37] and therefore the articles were derived from that study. Only web-based interventions were included that were intended to be used on more than one occasion and studies were excluded when no information on adherence was provided. 48 interventions targeted at mental health were selected for the current study. A within-group (WG) and between-group (BG) meta-analysis were performed and subsequently subgroup analyses regarding the relationship between the number and combinations of persuasive technology principles and effectiveness. The influence of adherence on the effectiveness was examined through a meta-regression analysis. For the WG meta-analysis 40 treatment groups were included. The BG meta-analysis included 19 studies. The mean pooled effect size in the WG meta-analysis was large and significant (Hedges' g=0.94), while for the BG meta-analysis this was moderate to large and significant (Hedges' g=0.78) in favor of the web-based interventions. With regard to the number of persuasive technology principles, the differences between the effect sizes in the subgroups were significant in the WG subgroup analyses for the total number of principles and for the number of principles in the three categories Primary Task Support, Dialogue Support, and Social Support. In the BG subgroup analyses only the difference in Primary Task Support was significant. An increase in the total number of principles and Dialogue Support principles yielded larger effect sizes in the WG subgroup analysis, indicating that more principles lead to better outcomes. The number of principles in the Primary Task Support (WG and BG) and Social Support (WG) did not show an upward trend but had varying effect sizes. We identified a number of combinations of principles that were more effective, but only in the WG analyses. The association between adherence and effectiveness was not significant. There is a relationship between the number of persuasive technology principles and the effectiveness of web-based interventions concerning mental health, however this does not always mean that implementing more principles leads to better outcomes. Regarding the combinations of principles, specific principles seemed to work well together (e.g. tunneling and tailoring; reminders and similarity; social learning and comparison), but adding another principle can diminish the effectiveness (e.g. tunneling, tailoring and reduction). In this study, an increase in adherence was not associated with larger effect sizes. The findings of this study can help developers to decide which persuasive principles to include to make web-based interventions more persuasive. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Religious Priming: A Meta-Analysis With a Focus on Prosociality.

PubMed

Shariff, Azim F; Willard, Aiyana K; Andersen, Teresa; Norenzayan, Ara

2016-02-01

Priming has emerged as a valuable tool within the psychological study of religion, allowing for tests of religion's causal effect on a number of psychological outcomes, such as prosocial behavior. As the literature has grown, questions about the reliability and boundary conditions of religious priming have arisen. We use a combination of traditional effect-size analyses, p-curve analyses, and adjustments for publication bias to evaluate the robustness of four types of religious priming (Analyses 1-3), review the empirical evidence for religion's effect specifically on prosocial behavior (Analyses 4-5), and test whether religious-priming effects generalize to individuals who report little or no religiosity (Analyses 6-7). Results across 93 studies and 11,653 participants show that religious priming has robust effects across a variety of outcome measures-prosocial measures included. Religious priming does not, however, reliably affect non-religious participants-suggesting that priming depends on the cognitive activation of culturally transmitted religious beliefs. © 2015 by the Society for Personality and Social Psychology, Inc.

Workplace health promotion: a meta-analysis of effectiveness.

PubMed

Rongen, Anne; Robroek, Suzan J W; van Lenthe, Frank J; Burdorf, Alex

2013-04-01

An unhealthy lifestyle may contribute to ill health, absence due to sickness, productivity loss at work, and reduced ability to work. Workplace health promotion programs (WHPPs) aim to improve lifestyle and consequently improve health, work ability, and work productivity. However, systematic reviews on intervention studies have reported small effects, and the overall evaluation of effectiveness of WHPPs is hampered by a large heterogeneity in interventions and study populations. This systematic review aims to investigate the influence of population, study and intervention characteristics, and study quality on the effectiveness of workplace health promotion programs. A systematic literature search was conducted identifying RCTs, published before June 2012, evaluating the effect of a WHPP aimed at smoking cessation, physical activity, healthy nutrition, and/or obesity on self-perceived health, work absence due to sickness, work productivity, or work ability. Studies were included in the meta-analyses if quantitative information was present to calculate an effect size (ES). A meta-analysis, stratified meta-analyses, and meta-regression analyses were performed in Spring 2012 using Comprehensive Meta-analysis software 2.0 and PAWS 17.0.2. In 18 studies describing 21 interventions, the overall effect of a WHPP was small (ES=0.24, 95% CI=0.14, 0.34). The effectiveness of a WHPP was larger in younger populations, in interventions with weekly contacts, and in studies in which the control group received no health promotion. A 2.6-fold lower effectiveness was observed for studies performing an intention-to-treat analysis and a 1.7-fold lower effectiveness for studies controlling for confounders. Studies of poor methodologic quality reported a 2.9-fold higher effect size of the WHPP. The effectiveness of a WHPP is partly determined by intervention characteristics and statistical analysis. High-quality RCTs reported lower effect sizes. It is important to determine the effectiveness of WHPPs in RCTs of high quality. Copyright © 2013 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

Failure to Report Effect Sizes: The Handling of Quantitative Results in Published Health Education and Behavior Research.

PubMed

Barry, Adam E; Szucs, Leigh E; Reyes, Jovanni V; Ji, Qian; Wilson, Kelly L; Thompson, Bruce

2016-10-01

Given the American Psychological Association's strong recommendation to always report effect sizes in research, scholars have a responsibility to provide complete information regarding their findings. The purposes of this study were to (a) determine the frequencies with which different effect sizes were reported in published, peer-reviewed articles in health education, promotion, and behavior journals and (b) discuss implications for reporting effect size in social science research. Across a 4-year time period (2010-2013), 1,950 peer-reviewed published articles were examined from the following six health education and behavior journals: American Journal of Health Behavior, American Journal of Health Promotion, Health Education & Behavior, Health Education Research, Journal of American College Health, and Journal of School Health Quantitative features from eligible manuscripts were documented using Qualtrics online survey software. Of the 1,245 articles in the final sample that reported quantitative data analyses, approximately 47.9% (n = 597) of the articles reported an effect size. While 16 unique types of effect size were reported across all included journals, many of the effect sizes were reported with little frequency across most journals. Overall, odds ratio/adjusted odds ratio (n = 340, 50.1%), Pearson r/r(2) (n = 162, 23.8%), and eta squared/partial eta squared (n = 46, 7.2%) accounted for the most frequently used effect size. Quality research practice requires both testing statistical significance and reporting effect size. However, our study shows that a substantial portion of published literature in health education and behavior lacks consistent reporting of effect size. © 2016 Society for Public Health Education.

Effects of sources of variability on sample sizes required for RCTs, applied to trials of lipid-altering therapies on carotid artery intima-media thickness.

PubMed

Gould, A Lawrence; Koglin, Joerg; Bain, Raymond P; Pinto, Cathy-Anne; Mitchel, Yale B; Pasternak, Richard C; Sapre, Aditi

2009-08-01

Studies measuring progression of carotid artery intima-media thickness (cIMT) have been used to estimate the effect of lipid-modifying therapies cardiovascular event risk. The likelihood that future cIMT clinical trials will detect a true treatment effect is estimated by leveraging results from prior studies. The present analyses assess the impact of between- and within-study variability based on currently published data from prior clinical studies on the likelihood that ongoing or future cIMT trials will detect the true treatment effect of lipid-modifying therapies. Published data from six contemporary cIMT studies (ASAP, ARBITER 2, RADIANCE 1, RADIANCE 2, ENHANCE, and METEOR) including data from a total of 3563 patients were examined. Bayesian and frequentist methods were used to assess the impact of between study variability on the likelihood of detecting true treatment effects on 1-year cIMT progression/regression and to provide a sample size estimate that would specifically compensate for the effect of between-study variability. In addition to the well-described within-study variability, there is considerable between-study variability associated with the measurement of annualized change in cIMT. Accounting for the additional between-study variability decreases the power for existing study designs. In order to account for the added between-study variability, it is likely that future cIMT studies would require a large increase in sample size in order to provide substantial probability (> or =90%) to have 90% power of detecting a true treatment effect.Limitation Analyses are based on study level data. Future meta-analyses incorporating patient-level data would be useful for confirmation. Due to substantial within- and between-study variability in the measure of 1-year change of cIMT, as well as uncertainty about progression rates in contemporary populations, future study designs evaluating the effect of new lipid-modifying therapies on atherosclerotic disease progression are likely to be challenged by large sample sizes in order to demonstrate a true treatment effect.

A meta-analysis of educational interventions designed to enhance cultural competence in professional nurses and nursing students.

PubMed

Gallagher, Ruth W; Polanin, Joshua R

2015-02-01

Increasing professional nurses' and nursing students cultural competence has been identified as one way to decrease the disparity of care for vulnerable and minority groups, but effectiveness of training programs to increase competence remains equivocal. The purpose of this project is to synthesize educational interventions designed to increase cultural competence in professional nurses and nursing students. A systematic review and meta-analysis was conducted to synthesize all existing studies on increasing cultural competence. A comprehensive search and screen procedures was conducted to locate all cultural competence interventions implemented with professional nurses and nursing students. Two independent researchers screened and coded the included studies. Effect sizes were calculated for each study and a random-effects meta-analysis was conducted. A total of 25 studies were included in the review. Two independent syntheses were conducted given the disparate nature of the effect size metrics. For the synthesis of treatment-control designed studies, the results revealed a non-statistically significant increase in cultural competence (g¯=.38, 95% CI: -.05, .79, p=.08). Moderator analyses indicated significant variation as a function of the measurements, participant types, and funding source. The pretest-posttest effect size synthesis revealed a significant increase in overall cultural competence (g¯=.45, 95% CI: .24, .66, p<.01). Moderator analyses indicated, however, that the effect sizes varied as functions of the measurement, funding source, and publication type. Interventions to increase cultural competence have shown varied effectiveness. Greater research is required to improve these interventions and promote cultural competence. Copyright © 2014 Elsevier Ltd. All rights reserved.

Interventions designed to reduce sedentary behaviours in young people: a review of reviews.

PubMed

Biddle, Stuart J H; Petrolini, Irene; Pearson, Natalie

2014-02-01

Leisure time is increasingly spent in sedentary pursuits such as screen-viewing (eg, television/DVD viewing and computer use), motorised travel, school/work and sitting-based socialising (eg, social media and chatting). Sedentary screen time, particularly TV, appears to play an important role in the aetiology of obesity due to its co-occurrence with other unhealthy behaviours such as snacking on energy-dense foods, low levels of physical activity and inadequate sleep. More information is needed on how to reduce sedentary behaviours. Most interventions have focused on young people and a number of systematic reviews exist on this topic. To synthesise systematic reviews and meta-analyses of interventions aimed at decreasing sedentary behaviours among children and adolescents. Papers were located from computerised and manual searches. Included articles were English language systematic reviews or meta-analyses of interventions aiming at reducing sedentary behaviour in children (<11 years) and adolescents (12-18 years). Ten papers met the inclusion criteria and were analysed. All reviews concluded some level of effectiveness in reducing time spent in sedentary behaviour. When an effect size was reported, there was a small but significant reduction in sedentary time (highest effect size=-0.29; CI -0.35 to -0.22). Moderator analyses showed a trend favouring interventions with children younger than 6 years. Effective strategies include the involvement of family, behavioural interventions and electronic TV monitoring devices. Results from systematic reviews and meta-analyses show that interventions to reduce children's sedentary behaviour have a small but significant effect. Future research should expand these findings examining interventions targeting different types of sedentary behaviours and the effectiveness of specific behaviour change techniques across different contexts and settings.

Maximizing sensitivity of the psychomotor vigilance test (PVT) to sleep loss.

PubMed

Basner, Mathias; Dinges, David F

2011-05-01

The psychomotor vigilance test (PVT) is among the most widely used measures of behavioral alertness, but there is large variation among published studies in PVT performance outcomes and test durations. To promote standardization of the PVT and increase its sensitivity and specificity to sleep loss, we determined PVT metrics and task durations that optimally discriminated sleep deprived subjects from alert subjects. Repeated-measures experiments involving 10-min PVT assessments every 2 h across both acute total sleep deprivation (TSD) and 5 days of chronic partial sleep deprivation (PSD). Controlled laboratory environment. 74 healthy subjects (34 female), aged 22-45 years. TSD experiment involving 33 h awake (N = 31 subjects) and a PSD experiment involving 5 nights of 4 h time in bed (N = 43 subjects). In a paired t-test paradigm and for both TSD and PSD, effect sizes of 10 different PVT performance outcomes were calculated. Effect sizes were high for both TSD (1.59-1.94) and PSD (0.88-1.21) for PVT metrics related to lapses and to measures of psychomotor speed, i.e., mean 1/RT (response time) and mean slowest 10% 1/RT. In contrast, PVT mean and median RT outcomes scored low to moderate effect sizes influenced by extreme values. Analyses facilitating only portions of the full 10-min PVT indicated that for some outcomes, high effect sizes could be achieved with PVT durations considerably shorter than 10 min, although metrics involving lapses seemed to profit from longer test durations in TSD. Due to their superior conceptual and statistical properties and high sensitivity to sleep deprivation, metrics involving response speed and lapses should be considered primary outcomes for the 10-min PVT. In contrast, PVT mean and median metrics, which are among the most widely used outcomes, should be avoided as primary measures of alertness. Our analyses also suggest that some shorter-duration PVT versions may be sensitive to sleep loss, depending on the outcome variable selected, although this will need to be confirmed in comparative analyses of separate duration versions of the PVT. Using both sensitive PVT metrics and optimal test durations maximizes the sensitivity of the PVT to sleep loss and therefore potentially decreases the sample size needed to detect the same neurobehavioral deficit. We propose criteria to better standardize the 10-min PVT and facilitate between-study comparisons and meta-analyses.

Fifty years of chasing lizards: new insights advance optimal escape theory.

PubMed

Samia, Diogo S M; Blumstein, Daniel T; Stankowich, Theodore; Cooper, William E

2016-05-01

Systematic reviews and meta-analyses often examine data from diverse taxa to identify general patterns of effect sizes. Meta-analyses that focus on identifying generalisations in a single taxon are also valuable because species in a taxon are more likely to share similar unique constraints. We conducted a comprehensive phylogenetic meta-analysis of flight initiation distance in lizards. Flight initiation distance (FID) is a common metric used to quantify risk-taking and has previously been shown to reflect adaptive decision-making. The past decade has seen an explosion of studies focused on quantifying FID in lizards, and, because lizards occur in a wide range of habitats, are ecologically diverse, and are typically smaller and differ physiologically from the better studied mammals and birds, they are worthy of detailed examination. We found that variables that reflect the costs or benefits of flight (being engaged in social interactions, having food available) as well as certain predator effects (predator size and approach speed) had large effects on FID in the directions predicted by optimal escape theory. Variables that were associated with morphology (with the exception of crypsis) and physiology had relatively small effects, whereas habitat selection factors typically had moderate to large effect sizes. Lizards, like other taxa, are very sensitive to the costs of flight. © 2015 Cambridge Philosophical Society.

Display size effects in visual search: analyses of reaction time distributions as mixtures.

PubMed

Reynolds, Ann; Miller, Jeff

2009-05-01

In a reanalysis of data from Cousineau and Shiffrin (2004) and two new visual search experiments, we used a likelihood ratio test to examine the full distributions of reaction time (RT) for evidence that the display size effect is a mixture-type effect that occurs on only a proportion of trials, leaving RT in the remaining trials unaffected, as is predicted by serial self-terminating search models. Experiment 1 was a reanalysis of Cousineau and Shiffrin's data, for which a mixture effect had previously been established by a bimodal distribution of RTs, and the results confirmed that the likelihood ratio test could also detect this mixture. Experiment 2 applied the likelihood ratio test within a more standard visual search task with a relatively easy target/distractor discrimination, and Experiment 3 applied it within a target identification search task within the same types of stimuli. Neither of these experiments provided any evidence for the mixture-type display size effect predicted by serial self-terminating search models. Overall, these results suggest that serial self-terminating search models may generally be applicable only with relatively difficult target/distractor discriminations, and then only for some participants. In addition, they further illustrate the utility of analysing full RT distributions in addition to mean RT.

Analysis and design of randomised clinical trials involving competing risks endpoints.

PubMed

Tai, Bee-Choo; Wee, Joseph; Machin, David

2011-05-19

In randomised clinical trials involving time-to-event outcomes, the failures concerned may be events of an entirely different nature and as such define a classical competing risks framework. In designing and analysing clinical trials involving such endpoints, it is important to account for the competing events, and evaluate how each contributes to the overall failure. An appropriate choice of statistical model is important for adequate determination of sample size. We describe how competing events may be summarised in such trials using cumulative incidence functions and Gray's test. The statistical modelling of competing events using proportional cause-specific and subdistribution hazard functions, and the corresponding procedures for sample size estimation are outlined. These are illustrated using data from a randomised clinical trial (SQNP01) of patients with advanced (non-metastatic) nasopharyngeal cancer. In this trial, treatment has no effect on the competing event of loco-regional recurrence. Thus the effects of treatment on the hazard of distant metastasis were similar via both the cause-specific (unadjusted csHR = 0.43, 95% CI 0.25 - 0.72) and subdistribution (unadjusted subHR 0.43; 95% CI 0.25 - 0.76) hazard analyses, in favour of concurrent chemo-radiotherapy followed by adjuvant chemotherapy. Adjusting for nodal status and tumour size did not alter the results. The results of the logrank test (p = 0.002) comparing the cause-specific hazards and the Gray's test (p = 0.003) comparing the cumulative incidences also led to the same conclusion. However, the subdistribution hazard analysis requires many more subjects than the cause-specific hazard analysis to detect the same magnitude of effect. The cause-specific hazard analysis is appropriate for analysing competing risks outcomes when treatment has no effect on the cause-specific hazard of the competing event. It requires fewer subjects than the subdistribution hazard analysis for a similar effect size. However, if the main and competing events are influenced in opposing directions by an intervention, a subdistribution hazard analysis may be warranted.

You Cannot Step Into the Same River Twice: When Power Analyses Are Optimistic.

PubMed

McShane, Blakeley B; Böckenholt, Ulf

2014-11-01

Statistical power depends on the size of the effect of interest. However, effect sizes are rarely fixed in psychological research: Study design choices, such as the operationalization of the dependent variable or the treatment manipulation, the social context, the subject pool, or the time of day, typically cause systematic variation in the effect size. Ignoring this between-study variation, as standard power formulae do, results in assessments of power that are too optimistic. Consequently, when researchers attempting replication set sample sizes using these formulae, their studies will be underpowered and will thus fail at a greater than expected rate. We illustrate this with both hypothetical examples and data on several well-studied phenomena in psychology. We provide formulae that account for between-study variation and suggest that researchers set sample sizes with respect to our generally more conservative formulae. Our formulae generalize to settings in which there are multiple effects of interest. We also introduce an easy-to-use website that implements our approach to setting sample sizes. Finally, we conclude with recommendations for quantifying between-study variation. © The Author(s) 2014.

The Hartung-Knapp-Sidik-Jonkman method for random effects meta-analysis is straightforward and considerably outperforms the standard DerSimonian-Laird method

PubMed Central

2014-01-01

Background The DerSimonian and Laird approach (DL) is widely used for random effects meta-analysis, but this often results in inappropriate type I error rates. The method described by Hartung, Knapp, Sidik and Jonkman (HKSJ) is known to perform better when trials of similar size are combined. However evidence in realistic situations, where one trial might be much larger than the other trials, is lacking. We aimed to evaluate the relative performance of the DL and HKSJ methods when studies of different sizes are combined and to develop a simple method to convert DL results to HKSJ results. Methods We evaluated the performance of the HKSJ versus DL approach in simulated meta-analyses of 2–20 trials with varying sample sizes and between-study heterogeneity, and allowing trials to have various sizes, e.g. 25% of the trials being 10-times larger than the smaller trials. We also compared the number of “positive” (statistically significant at p < 0.05) findings using empirical data of recent meta-analyses with > = 3 studies of interventions from the Cochrane Database of Systematic Reviews. Results The simulations showed that the HKSJ method consistently resulted in more adequate error rates than the DL method. When the significance level was 5%, the HKSJ error rates at most doubled, whereas for DL they could be over 30%. DL, and, far less so, HKSJ had more inflated error rates when the combined studies had unequal sizes and between-study heterogeneity. The empirical data from 689 meta-analyses showed that 25.1% of the significant findings for the DL method were non-significant with the HKSJ method. DL results can be easily converted into HKSJ results. Conclusions Our simulations showed that the HKSJ method consistently results in more adequate error rates than the DL method, especially when the number of studies is small, and can easily be applied routinely in meta-analyses. Even with the HKSJ method, extra caution is needed when there are = <5 studies of very unequal sizes. PMID:24548571

Prepotent response inhibition and interference control in autism spectrum disorders: two meta-analyses.

PubMed

Geurts, Hilde M; van den Bergh, Sanne F W M; Ruzzano, Laura

2014-08-01

There is a substantial amount of data providing evidence for, but also against the hypothesis that individuals with autism spectrum disorders (ASD) encounter inhibitory control deficits. ASD is often associated with interference control deficits rather than prepotent response inhibition. Moreover, the developmental trajectory for these inhibitory control processes is hypothesized to differ in ASD as compared to typical development. In efforts to gain a more comprehensive perspective of inhibition in ASD, separate quantitative analysis for prepotent response inhibition studies and interference control studies were conducted. Together, these two meta-analyses included 41 studies with a combined sample size of 1,091 people with ASD (M age 14.8 years), and 1,306 typically developing (TD) controls (M age 13.8 years).The meta-analyses indicated that individuals with ASD show increased difficulties in prepotent response inhibition (effect size 0.55) and in interference control (effect size 0.31). In addition, age was a relevant moderator for prepotent response inhibition but not for interference control. Exploratory analyses revealed that when IQ was taken into account, heterogeneity considerably decreased among interference control studies but not among prepotent response inhibition. In contrast to the general belief, both prepotent response inhibition and interference control problems were observed in individuals with ASD. However, a large variation between studies was also found. Therefore, there remain factors beyond inhibition type, age, or IQ that significantly influence inhibitory control performance among individuals with ASD. © 2014 International Society for Autism Research, Wiley Periodicals, Inc.

Adjusting data to body size: a comparison of methods as applied to quantitative trait loci analysis of musculoskeletal phenotypes.

PubMed

Lang, Dean H; Sharkey, Neil A; Lionikas, Arimantas; Mack, Holly A; Larsson, Lars; Vogler, George P; Vandenbergh, David J; Blizard, David A; Stout, Joseph T; Stitt, Joseph P; McClearn, Gerald E

2005-05-01

The aim of this study was to compare three methods of adjusting skeletal data for body size and examine their use in QTL analyses. It was found that dividing skeletal phenotypes by body mass index induced erroneous QTL results. The preferred method of body size adjustment was multiple regression. Many skeletal studies have reported strong correlations between phenotypes for muscle, bone, and body size, and these correlations add to the difficulty in identifying genetic influence on skeletal traits that are not mediated through overall body size. Quantitative trait loci (QTL) identified for skeletal phenotypes often map to the same chromosome regions as QTLs for body size. The actions of a QTL identified as influencing BMD could therefore be mediated through the generalized actions of growth on body size or muscle mass. Three methods of adjusting skeletal phenotypes to body size were performed on morphologic, structural, and compositional measurements of the femur and tibia in 200-day-old C57BL/6J x DBA/2 (BXD) second generation (F(2)) mice (n = 400). A common method of removing the size effect has been through the use of ratios. This technique and two alternative techniques using simple and multiple regression were performed on muscle and skeletal data before QTL analyses, and the differences in QTL results were examined. The use of ratios to remove the size effect was shown to increase the size effect by inducing spurious correlations, thereby leading to inaccurate QTL results. Adjustments for body size using multiple regression eliminated these problems. Multiple regression should be used to remove the variance of co-factors related to skeletal phenotypes to allow for the study of genetic influence independent of correlated phenotypes. However, to better understand the genetic influence, adjusted and unadjusted skeletal QTL results should be compared. Additional insight can be gained by observing the difference in LOD score between the adjusted and nonadjusted phenotypes. Identifying QTLs that exert their effects on skeletal phenotypes through body size-related pathways as well as those having a more direct and independent influence on bone are equally important in deciphering the complex physiologic pathways responsible for the maintenance of bone health.

A descriptive study of effect-size reporting in research reviews.

PubMed

Floyd, Judith A

2017-06-01

To describe effect-size reporting in research reviews completed in support of evidence-based practice in nursing. Many research reviews report nurses' critical appraisal of level, quality and overall strength of evidence available to address clinical questions. Several studies of research-review quality suggest effect-size information would be useful to include in these reviews, but none focused on reviewers' attention to effect sizes. Descriptive. One hundred and four reviews indexed in CINAHL as systematic reviews and published from July 2012-February 2014 were examined. Papers were required to be peer-reviewed, written in English, contain an abstract and have at least one nurse author. Reviews were excluded if they did not use critical appraisal methods to address evidence of correlation, prediction or effectiveness. Data from remaining papers (N = 73) were extracted by three or more independent coders using a structured coding form and detailed codebook. Data were stored, viewed and analysed using Microsoft Office Excel ® spreadsheet functions. Sixteen percent (n = 12) of the sample contained effect-size information. Of the 12, six included all the effect-size information recommended by APA guidelines. Independent of completeness of reporting, seven contained discussion of effect sizes in the paper, but none included effect-size information in abstracts. Research reviews available to practicing nurses often fail to include information needed to accurately assess how much improvement may result from implementation of evidence-based policies, programs, protocols or practices. Manuscript reviewers are urged to hold authors to APA standards for reporting/discussing effect-size information in both primary research reports and research reviews. © 2016 John Wiley & Sons Ltd.

The Influence of Experimental Design on the Detection of Performance Differences

ERIC Educational Resources Information Center

Bates, B. T.; Dufek, J. S.; James, C. R.; Harry, J. R.; Eggleston, J. D.

2016-01-01

We demonstrate the effect of sample and trial size on statistical outcomes for single-subject analyses (SSA) and group analyses (GA) for a frequently studied performance activity and common intervention. Fifty strides of walking data collected in two blocks of 25 trials for two shoe conditions were analyzed for samples of five, eight, 10, and 12…

Treatment Effect on Recidivism for Juveniles Who Have Sexually Offended: a Multilevel Meta-Analysis.

PubMed

Ter Beek, Ellis; Spruit, Anouk; Kuiper, Chris H Z; van der Rijken, Rachel E A; Hendriks, Jan; Stams, Geert Jan J M

2018-04-01

The current study investigated the effect on recidivism of treatment aimed at juveniles who have sexually offended. It also assessed the potential moderating effect of type of recidivism, and several treatment, participant and study characteristics. In total, 14 published and unpublished primary studies, making use of a comparison group and reporting on official recidivism rates, were included in a multilevel meta-analysis. This resulted in the use of 77 effect sizes, and 1726 participants. A three-level meta-analytic model was used to calculate the combined effect sizes (Cohens d) and to perform moderator analyses. Study quality was assessed with the EPHPP Quality Assessment Tool for Quantitative Studies. A moderate effect size was found (d = 0.37), indicating that the treatment groups achieved an estimated relative reduction in recidivism of 20.5% as compared to comparison groups. However, after controlling for publication bias, a significant treatment effect was no longer found. Type of recidivism did not moderate the effect of treatment, indicating that treatment groups were equally effective for all types of recidivism. Also, no moderating effects of participant or treatment characteristics were found. Regarding study characteristics, a shorter follow up time showed a trend for larger effect sizes, and the effect size calculation based on proportions yielded larger effect sizes than calculation via mean frequency of offending. Implications for future research and clinical practice are discussed.

Evidence, models, conservation programs and limits to management

USGS Publications Warehouse

Nichols, J.D.

2012-01-01

Walsh et al. (2012) emphasized the importance of obtaining evidence to assess the effects of management actions on state variables relevant to objectives of conservation programs. They focused on malleefowl Leipoa ocellata, ground-dwelling Australian megapodes listed as vulnerable. They noted that although fox Vulpes vulpes baiting is the main management action used in malleefowl conservation throughout southern Australia, evidence of the effectiveness of this action is limited and currently debated. Walsh et al. (2012) then used data from 64 sites monitored for malleefowl and foxes over 23 years to assess key functional relationships relevant to fox control as a conservation action for malleefowl. In one set of analyses, Walsh et al. (2012) focused on two relationships: fox baiting investment versus fox presence, and fox presence versus malleefowl population size and rate of population change. Results led to the counterintuitive conclusion that increases in investments in fox control produced slight decreases in malleefowl population size and growth. In a second set of analyses, Walsh et al. (2012) directly assessed the relationship between investment in fox baiting and malleefowl population size and rate of population change. This set of analyses showed no significant relationship between investment in fox population control and malleefowl population growth. Both sets of analyses benefited from the incorporation of key environmental covariates hypothesized to influence these management relationships. Walsh et al. (2012) concluded that "in most situations, malleefowl conservation did not effectively benefit from fox baiting at current levels of investment." In this commentary, I discuss the work of Walsh et al. (2012) using the conceptual framework of structured decision making (SDM). In doing so, I accept their analytic results and associated conclusions as accurate and discuss basic ideas about evidence, conservation and limits to management.

The impact of multiple endpoint dependency on Q and I(2) in meta-analysis.

PubMed

Thompson, Christopher Glen; Becker, Betsy Jane

2014-09-01

A common assumption in meta-analysis is that effect sizes are independent. When correlated effect sizes are analyzed using traditional univariate techniques, this assumption is violated. This research assesses the impact of dependence arising from treatment-control studies with multiple endpoints on homogeneity measures Q and I(2) in scenarios using the unbiased standardized-mean-difference effect size. Univariate and multivariate meta-analysis methods are examined. Conditions included different overall outcome effects, study sample sizes, numbers of studies, between-outcomes correlations, dependency structures, and ways of computing the correlation. The univariate approach used typical fixed-effects analyses whereas the multivariate approach used generalized least-squares (GLS) estimates of a fixed-effects model, weighted by the inverse variance-covariance matrix. Increased dependence among effect sizes led to increased Type I error rates from univariate models. When effect sizes were strongly dependent, error rates were drastically higher than nominal levels regardless of study sample size and number of studies. In contrast, using GLS estimation to account for multiple-endpoint dependency maintained error rates within nominal levels. Conversely, mean I(2) values were not greatly affected by increased amounts of dependency. Last, we point out that the between-outcomes correlation should be estimated as a pooled within-groups correlation rather than using a full-sample estimator that does not consider treatment/control group membership. Copyright © 2014 John Wiley & Sons, Ltd.

Do Patients’ Symptoms and Interpersonal Problems Improve in Psychotherapeutic Hospital Treatment in Germany? - A Systematic Review and Meta-Analysis

PubMed Central

Liebherz, Sarah; Rabung, Sven

2014-01-01

Background In Germany, inpatient psychotherapy plays a unique role in the treatment of patients with common mental disorders of higher severity. In addition to psychiatric inpatient services, psychotherapeutic hospital treatment and psychosomatic rehabilitation are offered as independent inpatient treatment options. This meta-analysis aims to provide systematic evidence for psychotherapeutic hospital treatment in Germany regarding its effects on symptomatic and interpersonal impairment. Methodology Relevant papers were identified by electronic database search and hand search. Randomized controlled trials as well as naturalistic prospective studies (including post-therapy and follow-up assessments) evaluating psychotherapeutic hospital treatment of mentally ill adults in Germany were included. Outcomes were required to be quantified by either the Symptom-Checklist (SCL-90-R or short versions) or the Inventory of Interpersonal Problems (IIP-64 or short versions). Effect sizes (Hedges’ g) were combined using random effect models. Principal Findings Sixty-seven papers representing 59 studies fulfilled inclusion criteria. Meta-analysis yielded a medium within-group effect size for symptom change at discharge (g = 0.72; 95% CI 0.68–0.76), with a small reduction to follow-up (g = 0.61; 95% CI 0.55–0.68). Regarding interpersonal problems, a small effect size was found at discharge (g = 0.35; 95% CI 0.29–0.41), which increased to follow-up (g = 0.48; 95% CI 0.36–0.60). While higher impairment at intake was associated with a larger effect size in both measures, longer treatment duration was related to lower effect sizes in SCL GSI and to larger effect sizes in IIP Total. Conclusions Psychotherapeutic hospital treatment may be considered an effective treatment. In accordance with Howard’s phase model of psychotherapy outcome, the present study demonstrated that symptom distress changes more quickly and strongly than interpersonal problems. Preliminary analyses show impairment at intake and treatment duration to be the strongest outcome predictors. Further analyses regarding this relationship are required. PMID:25141289

On meta- and mega-analyses for gene–environment interactions

PubMed Central

Huang, Jing; Liu, Yulun; Vitale, Steve; Penning, Trevor M.; Whitehead, Alexander S.; Blair, Ian A.; Vachani, Anil; Clapper, Margie L.; Muscat, Joshua E.; Lazarus, Philip; Scheet, Paul; Moore, Jason H.; Chen, Yong

2017-01-01

Gene-by-environment (G × E) interactions are important in explaining the missing heritability and understanding the causation of complex diseases, but a single, moderately sized study often has limited statistical power to detect such interactions. With the increasing need for integrating data and reporting results from multiple collaborative studies or sites, debate over choice between mega- versus meta-analysis continues. In principle, data from different sites can be integrated at the individual level into a “mega” data set, which can be fit by a joint “mega-analysis.” Alternatively, analyses can be done at each site, and results across sites can be combined through a “meta-analysis” procedure without integrating individual level data across sites. Although mega-analysis has been advocated in several recent initiatives, meta-analysis has the advantages of simplicity and feasibility, and has recently led to several important findings in identifying main genetic effects. In this paper, we conducted empirical and simulation studies, using data from a G × E study of lung cancer, to compare the mega- and meta-analyses in four commonly used G × E analyses under the scenario that the number of studies is small and sample sizes of individual studies are relatively large. We compared the two data integration approaches in the context of fixed effect models and random effects models separately. Our investigations provide valuable insights in understanding the differences between mega- and meta-analyses in practice of combining small number of studies in identifying G × E interactions. PMID:29110346

On meta- and mega-analyses for gene-environment interactions.

PubMed

Huang, Jing; Liu, Yulun; Vitale, Steve; Penning, Trevor M; Whitehead, Alexander S; Blair, Ian A; Vachani, Anil; Clapper, Margie L; Muscat, Joshua E; Lazarus, Philip; Scheet, Paul; Moore, Jason H; Chen, Yong

2017-12-01

Gene-by-environment (G × E) interactions are important in explaining the missing heritability and understanding the causation of complex diseases, but a single, moderately sized study often has limited statistical power to detect such interactions. With the increasing need for integrating data and reporting results from multiple collaborative studies or sites, debate over choice between mega- versus meta-analysis continues. In principle, data from different sites can be integrated at the individual level into a "mega" data set, which can be fit by a joint "mega-analysis." Alternatively, analyses can be done at each site, and results across sites can be combined through a "meta-analysis" procedure without integrating individual level data across sites. Although mega-analysis has been advocated in several recent initiatives, meta-analysis has the advantages of simplicity and feasibility, and has recently led to several important findings in identifying main genetic effects. In this paper, we conducted empirical and simulation studies, using data from a G × E study of lung cancer, to compare the mega- and meta-analyses in four commonly used G × E analyses under the scenario that the number of studies is small and sample sizes of individual studies are relatively large. We compared the two data integration approaches in the context of fixed effect models and random effects models separately. Our investigations provide valuable insights in understanding the differences between mega- and meta-analyses in practice of combining small number of studies in identifying G × E interactions. © 2017 WILEY PERIODICALS, INC.

Predictors of persistent pain after total knee arthroplasty: a systematic review and meta-analysis.

PubMed

Lewis, G N; Rice, D A; McNair, P J; Kluger, M

2015-04-01

Several studies have identified clinical, psychosocial, patient characteristic, and perioperative variables that are associated with persistent postsurgical pain; however, the relative effect of these variables has yet to be quantified. The aim of the study was to provide a systematic review and meta-analysis of predictor variables associated with persistent pain after total knee arthroplasty (TKA). Included studies were required to measure predictor variables prior to or at the time of surgery, include a pain outcome measure at least 3 months post-TKA, and include a statistical analysis of the effect of the predictor variable(s) on the outcome measure. Counts were undertaken of the number of times each predictor was analysed and the number of times it was found to have a significant relationship with persistent pain. Separate meta-analyses were performed to determine the effect size of each predictor on persistent pain. Outcomes from studies implementing uni- and multivariable statistical models were analysed separately. Thirty-two studies involving almost 30 000 patients were included in the review. Preoperative pain was the predictor that most commonly demonstrated a significant relationship with persistent pain across uni- and multivariable analyses. In the meta-analyses of data from univariate models, the largest effect sizes were found for: other pain sites, catastrophizing, and depression. For data from multivariate models, significant effects were evident for: catastrophizing, preoperative pain, mental health, and comorbidities. Catastrophizing, mental health, preoperative knee pain, and pain at other sites are the strongest independent predictors of persistent pain after TKA. © The Author 2014. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Preliminary Empirical Model of Crucial Determinants of Best Practice for Peer Tutoring on Academic Achievement

ERIC Educational Resources Information Center

Leung, Kim Chau

2015-01-01

Previous meta-analyses of the effects of peer tutoring on academic achievement have been plagued with theoretical and methodological flaws. Specifically, these studies have not adopted both fixed and mixed effects models for analyzing the effect size; they have not evaluated the moderating effect of some commonly used parameters, such as comparing…

Relationships fade with time: a meta-analysis of temporal trends in publication in ecology and evolution.

PubMed Central

Jennions, Michael D; Møller, Anders P

2002-01-01

Both significant positive and negative relationships between the magnitude of research findings (their 'effect size') and their year of publication have been reported in a few areas of biology. These trends have been attributed to Kuhnian paradigm shifts, scientific fads and bias in the choice of study systems. Here we test whether or not these isolated cases reflect a more general trend. We examined the relationship using effect sizes extracted from 44 peer-reviewed meta-analyses covering a wide range of topics in ecological and evolutionary biology. On average, there was a small but significant decline in effect size with year of publication. For the original empirical studies there was also a significant decrease in effect size as sample size increased. However, the effect of year of publication remained even after we controlled for sampling effort. Although these results have several possible explanations, it is suggested that a publication bias against non-significant or weaker findings offers the most parsimonious explanation. As in the medical sciences, non-significant results may take longer to publish and studies with both small sample sizes and non-significant results may be less likely to be published. PMID:11788035

Sexual Assault Education Programs: A Meta-Analytic Examination of Their Effectiveness

ERIC Educational Resources Information Center

Anderson, Linda A.; Whiston, Susan C.

2005-01-01

Meta-analyses of the effectiveness of college sexual assault education programs on seven outcome measure categories were conducted using 69 studies that involved 102 treatment interventions and 18,172 participants. Five of the outcome categories had significant average effect sizes (i.e., rape attitudes, rape-related attitudes, rape knowledge,…

LOD score exclusion analyses for candidate genes using random population samples.

PubMed

Deng, H W; Li, J; Recker, R R

2001-05-01

While extensive analyses have been conducted to test for, no formal analyses have been conducted to test against, the importance of candidate genes with random population samples. We develop a LOD score approach for exclusion analyses of candidate genes with random population samples. Under this approach, specific genetic effects and inheritance models at candidate genes can be analysed and if a LOD score is < or = - 2.0, the locus can be excluded from having an effect larger than that specified. Computer simulations show that, with sample sizes often employed in association studies, this approach has high power to exclude a gene from having moderate genetic effects. In contrast to regular association analyses, population admixture will not affect the robustness of our analyses; in fact, it renders our analyses more conservative and thus any significant exclusion result is robust. Our exclusion analysis complements association analysis for candidate genes in random population samples and is parallel to the exclusion mapping analyses that may be conducted in linkage analyses with pedigrees or relative pairs. The usefulness of the approach is demonstrated by an application to test the importance of vitamin D receptor and estrogen receptor genes underlying the differential risk to osteoporotic fractures.

GWAS of 126,559 Individuals Identifies Genetic Variants Associated with Educational Attainment

PubMed Central

Rietveld, Cornelius A.; Medland, Sarah E.; Derringer, Jaime; Yang, Jian; Esko, Tõnu; Martin, Nicolas W.; Westra, Harm-Jan; Shakhbazov, Konstantin; Abdellaoui, Abdel; Agrawal, Arpana; Albrecht, Eva; Alizadeh, Behrooz Z.; Amin, Najaf; Barnard, John; Baumeister, Sebastian E.; Benke, Kelly S.; Bielak, Lawrence F.; Boatman, Jeffrey A.; Boyle, Patricia A.; Davies, Gail; de Leeuw, Christiaan; Eklund, Niina; Evans, Daniel S.; Ferhmann, Rudolf; Fischer, Krista; Gieger, Christian; Gjessing, Håkon K.; Hägg, Sara; Harris, Jennifer R.; Hayward, Caroline; Holzapfel, Christina; Ibrahim-Verbaas, Carla A.; Ingelsson, Erik; Jacobsson, Bo; Joshi, Peter K.; Jugessur, Astanand; Kaakinen, Marika; Kanoni, Stavroula; Karjalainen, Juha; Kolcic, Ivana; Kristiansson, Kati; Kutalik, Zoltán; Lahti, Jari; Lee, Sang H.; Lin, Peng; Lind, Penelope A.; Liu, Yongmei; Lohman, Kurt; Loitfelder, Marisa; McMahon, George; Vidal, Pedro Marques; Meirelles, Osorio; Milani, Lili; Myhre, Ronny; Nuotio, Marja-Liisa; Oldmeadow, Christopher J.; Petrovic, Katja E.; Peyrot, Wouter J.; Polašek, Ozren; Quaye, Lydia; Reinmaa, Eva; Rice, John P.; Rizzi, Thais S.; Schmidt, Helena; Schmidt, Reinhold; Smith, Albert V.; Smith, Jennifer A.; Tanaka, Toshiko; Terracciano, Antonio; van der Loos, Matthijs J.H.M.; Vitart, Veronique; Völzke, Henry; Wellmann, Jürgen; Yu, Lei; Zhao, Wei; Allik, Jüri; Attia, John R.; Bandinelli, Stefania; Bastardot, François; Beauchamp, Jonathan; Bennett, David A.; Berger, Klaus; Bierut, Laura J.; Boomsma, Dorret I.; Bültmann, Ute; Campbell, Harry; Chabris, Christopher F.; Cherkas, Lynn; Chung, Mina K.; Cucca, Francesco; de Andrade, Mariza; De Jager, Philip L.; De Neve, Jan-Emmanuel; Deary, Ian J.; Dedoussis, George V.; Deloukas, Panos; Dimitriou, Maria; Eiriksdottir, Gudny; Elderson, Martin F.; Eriksson, Johan G.; Evans, David M.; Faul, Jessica D.; Ferrucci, Luigi; Garcia, Melissa E.; Grönberg, Henrik; Gudnason, Vilmundur; Hall, Per; Harris, Juliette M.; Harris, Tamara B.; Hastie, Nicholas D.; Heath, Andrew C.; Hernandez, Dena G.; Hoffmann, Wolfgang; Hofman, Adriaan; Holle, Rolf; Holliday, Elizabeth G.; Hottenga, Jouke-Jan; Iacono, William G.; Illig, Thomas; Järvelin, Marjo-Riitta; Kähönen, Mika; Kaprio, Jaakko; Kirkpatrick, Robert M.; Kowgier, Matthew; Latvala, Antti; Launer, Lenore J.; Lawlor, Debbie A.; Lehtimäki, Terho; Li, Jingmei; Lichtenstein, Paul; Lichtner, Peter; Liewald, David C.; Madden, Pamela A.; Magnusson, Patrik K. E.; Mäkinen, Tomi E.; Masala, Marco; McGue, Matt; Metspalu, Andres; Mielck, Andreas; Miller, Michael B.; Montgomery, Grant W.; Mukherjee, Sutapa; Nyholt, Dale R.; Oostra, Ben A.; Palmer, Lyle J.; Palotie, Aarno; Penninx, Brenda; Perola, Markus; Peyser, Patricia A.; Preisig, Martin; Räikkönen, Katri; Raitakari, Olli T.; Realo, Anu; Ring, Susan M.; Ripatti, Samuli; Rivadeneira, Fernando; Rudan, Igor; Rustichini, Aldo; Salomaa, Veikko; Sarin, Antti-Pekka; Schlessinger, David; Scott, Rodney J.; Snieder, Harold; Pourcain, Beate St; Starr, John M.; Sul, Jae Hoon; Surakka, Ida; Svento, Rauli; Teumer, Alexander; Tiemeier, Henning; Rooij, Frank JAan; Van Wagoner, David R.; Vartiainen, Erkki; Viikari, Jorma; Vollenweider, Peter; Vonk, Judith M.; Waeber, Gérard; Weir, David R.; Wichmann, H.-Erich; Widen, Elisabeth; Willemsen, Gonneke; Wilson, James F.; Wright, Alan F.; Conley, Dalton; Davey-Smith, George; Franke, Lude; Groenen, Patrick J. F.; Hofman, Albert; Johannesson, Magnus; Kardia, Sharon L.R.; Krueger, Robert F.; Laibson, David; Martin, Nicholas G.; Meyer, Michelle N.; Posthuma, Danielle; Thurik, A. Roy; Timpson, Nicholas J.; Uitterlinden, André G.; van Duijn, Cornelia M.; Visscher, Peter M.; Benjamin, Daniel J.; Cesarini, David; Koellinger, Philipp D.

2013-01-01

A genome-wide association study of educational attainment was conducted in a discovery sample of 101,069 individuals and a replication sample of 25,490. Three independent SNPs are genome-wide significant (rs9320913, rs11584700, rs4851266), and all three replicate. Estimated effects sizes are small (R2 ≈ 0.02%), approximately 1 month of schooling per allele. A linear polygenic score from all measured SNPs accounts for ≈ 2% of the variance in both educational attainment and cognitive function. Genes in the region of the loci have previously been associated with health, cognitive, and central nervous system phenotypes, and bioinformatics analyses suggest the involvement of the anterior caudate nucleus. These findings provide promising candidate SNPs for follow-up work, and our effect size estimates can anchor power analyses in social-science genetics. PMID:23722424

Meta-analysis of the effects of repetitive transcranial magnetic stimulation (rTMS) on negative and positive symptoms in schizophrenia

PubMed Central

Freitas, Catarina; Fregni, Felipe; Pascual-Leone, Alvaro

2009-01-01

Background A growing body of evidence suggests that repetitive transcranial magnetic stimulation (rTMS) can alleviate negative and positive symptoms of refractory schizophrenia. However, trials to date have been small and results are mixed. Methods We performed meta-analyses of all prospective studies of the therapeutic application of rTMS in refractory schizophrenia assessing the effects of high-frequency rTMS to the left dorsolateral prefrontal cortex (DLPFC) to treat negative symptoms, and low-frequency rTMS to the left temporo-parietal cortex (TPC) to treat auditory hallucinations (AH) and overall positive symptoms. Results When analyzing controlled (active arms) and uncontrolled studies together, the effect sizes showed significant and moderate effects of rTMS on negative and positive symptoms (based on PANSS-N or SANS, and PANSS-P or SAPS, respectively). However, the analysis for the sham-controlled studies revealed a small non-significant effect size for negative (0.27, p=0.417) and for positive symptoms (0.17, p=0.129). When specifically analyzing AH (based on AHRS, HCS or SAH), the effect size for the sham-controlled studies was large and significant (1.04; p=0.002). Conclusions These meta-analyses support the need for further controlled, larger trials to assess the clinical efficacy of rTMS on negative and positive symptoms of schizophrenia, while suggesting the need for exploration for alternative stimulation protocols. PMID:19138833

Comparing peracetic acid and hypochlorite for disinfection of combined sewer overflows: Effects of suspended-solids and pH.

PubMed

McFadden, M; Loconsole, J; Schockling, A J; Nerenberg, R; Pavissich, J P

2017-12-01

Peracetic acid (PAA) is an alternative disinfectant that may be effective for combined sewer overflow (CSO) disinfection, but little is known about the effect of particle size on PAA disinfection efficiency. In this work, PAA and hypochlorite were compared as disinfectants, with a focus on the effect of wastewater particles. Inactivation experiments were conducted on suspended cultures of Escherichia coli and wastewater suspended solids. Tested size fractions included particle diameters <10μm, <100μm, and raw wastewater. Chlorine disinfection efficiency decreased with increasing solids size. However, solids size had little effect on PAA disinfection. The PAA disinfection efficiency decreased at pH values above 7.5. Live/dead staining revealed that PAA disinfection leaves most cells in a viable but non-culturable condition. Fourier transform infrared spectroscopy (FTIR) analyses suggests that PAA and hypochlorite may inactivate E. coli bacteria by similar mechanisms. Copyright © 2017 Elsevier B.V. All rights reserved.

Coevolution of female and male genital components to avoid genital size mismatches in sexually dimorphic spiders.

PubMed

Lupše, Nik; Cheng, Ren-Chung; Kuntner, Matjaž

2016-08-17

In most animal groups, it is unclear how body size variation relates to genital size differences between the sexes. While most morphological features tend to scale with total somatic size, this does not necessarily hold for genitalia because divergent evolution in somatic size between the sexes would cause genital size mismatches. Theory predicts that the interplay of female-biased sexual size dimorphism (SSD) and sexual genital size dimorphism (SGD) should adhere to the 'positive genital divergence', the 'constant genital divergence', or the 'negative genital divergence' model, but these models remain largely untested. We test their validity in the spider family Nephilidae known for the highest degrees of SSD among terrestrial animals. Through comparative analyses of sex-specific somatic and genital sizes, we first demonstrate that 99 of the 351 pairs of traits are phylogenetically correlated. Through factor analyses we then group these traits for MCMCglmm analyses that test broader correlation patterns, and these reveal significant correlations in 10 out of the 36 pairwise comparisons. Both types of analyses agree that female somatic and internal genital sizes evolve independently. While sizes of non-intromittent male genital parts coevolve with male body size, the size of the intromittent male genital parts is independent of the male somatic size. Instead, male intromittent genital size coevolves with female (external and, in part, internal) genital size. All analyses also agree that SGD and SSD evolve independently. Internal dimensions of female genitalia evolve independently of female body size in nephilid spiders, and similarly, male intromittent genital size evolves independently of the male body size. The size of the male intromittent organ (the embolus) and the sizes of female internal and external genital components thus seem to respond to selection against genital size mismatches. In accord with these interpretations, we reject the validity of the existing theoretical models of genital and somatic size dimorphism in spiders.

The Relationship Between Homework Compliance and Therapy Outcomes: An Updated Meta-Analysis.

PubMed

Mausbach, Brent T; Moore, Raeanne; Roesch, Scott; Cardenas, Veronica; Patterson, Thomas L

2010-10-01

The current study was an updated meta-analysis of manuscripts since the year 2000 examining the effects of homework compliance on treatment outcome. A total of 23 studies encompassing 2,183 subjects were included. Results indicated a significant relationship between homework compliance and treatment outcome suggesting a small to medium effect (r = .26; 95% CI = .19-.33). Moderator analyses were conducted to determine the differential effect size of homework on treatment outcome by target symptoms (e.g., depression; anxiety), source of homework rating (e.g., client; therapist), timing of homework rating (e.g., retroactive vs. contemporaneous), and type of homework rating (e.g., Likert; total homeworks completed). Results indicated that effect sizes were robust across target symptoms, but differed by source of homework rating, timing of homework rating, and type of homework rating. Specifically, studies utilizing combined client and therapist ratings of compliance had significantly higher mean effect size relative to those using therapist only assessments and those using objective assessments. Further, studies that rated the percentage of homeworks completed had a significantly lower mean effect size compared to studies using Likert ratings, and retroactive assessments had higher effect size than contemporaneous assessments.

The Relationship Between Homework Compliance and Therapy Outcomes: An Updated Meta-Analysis

PubMed Central

Moore, Raeanne; Roesch, Scott; Cardenas, Veronica; Patterson, Thomas L.

2010-01-01

The current study was an updated meta-analysis of manuscripts since the year 2000 examining the effects of homework compliance on treatment outcome. A total of 23 studies encompassing 2,183 subjects were included. Results indicated a significant relationship between homework compliance and treatment outcome suggesting a small to medium effect (r = .26; 95% CI = .19–.33). Moderator analyses were conducted to determine the differential effect size of homework on treatment outcome by target symptoms (e.g., depression; anxiety), source of homework rating (e.g., client; therapist), timing of homework rating (e.g., retroactive vs. contemporaneous), and type of homework rating (e.g., Likert; total homeworks completed). Results indicated that effect sizes were robust across target symptoms, but differed by source of homework rating, timing of homework rating, and type of homework rating. Specifically, studies utilizing combined client and therapist ratings of compliance had significantly higher mean effect size relative to those using therapist only assessments and those using objective assessments. Further, studies that rated the percentage of homeworks completed had a significantly lower mean effect size compared to studies using Likert ratings, and retroactive assessments had higher effect size than contemporaneous assessments. PMID:20930925

Variable percentage sampler

DOEpatents

Miller, Jr., William H.

1976-01-01

A remotely operable sampler is provided for obtaining variable percentage samples of nuclear fuel particles and the like for analyses. The sampler has a rotating cup for a sample collection chamber designed so that the effective size of the sample inlet opening to the cup varies with rotational speed. Samples of a desired size are withdrawn from a flowing stream of particles without a deterrent to the flow of remaining particles.

Post hoc analyses: after the facts.

PubMed

Srinivas, Titte R; Ho, Bing; Kang, Joseph; Kaplan, Bruce

2015-01-01

Prospective clinical trials are constructed with high levels of internal validity. Sample size and power considerations usually address primary endpoints. Primary endpoints have traditionally included events that are becoming increasingly less common and thus have led to growing use of composite endpoints and noninferiority trial designs in transplantation. This approach may mask real clinical benefit in one or the other domain with regard to either clinically relevant secondary endpoints or other unexpected findings. In addition, endpoints solely chosen based on power considerations are prone to misjudgment of actual treatment effect size as well as consistency of that effect. In the instances where treatment effects may have been underestimated, valuable information may be lost if buried within a composite endpoint. In all these cases, analyses and post hoc analyses of data become relevant in informing practitioners about clinical benefits or safety signals that may not be captured by the primary endpoint. On the other hand, there are many pitfalls in using post hoc determined endpoints. This short review is meant to allow readers to appreciate post hoc analysis not as an entity with a single approach, but rather as an analysis with unique limitations and strengths that often raise new questions to be addressed in further inquiries.

The Influence of Thermodynamic Phase on the Retrieval of Mixed-Phase Cloud Microphysical and Optical Properties in the Visible and Near Infrared Region

NASA Technical Reports Server (NTRS)

Lee, Joonsuk; Yang, Ping; Dessler, Andrew E.; Baum, Bryan A.; Platnick, Steven

2005-01-01

Cloud microphysical and optical properties are inferred from the bidirectional reflectances simulated for a single-layered cloud consisting of an external mixture of ice particles and liquid droplets. The reflectances are calculated with a rigorous discrete ordinates radiative transfer model and are functions of the cloud effective particle size, the cloud optical thickness, and the values of the ice fraction in the cloud (i.e., the ratio of ice water content to total water content). In the present light scattering and radiative transfer simulations, the ice fraction is assumed to be vertically homogeneous; the habit (shape) percentage as a function of ice particle size is consistent with that used for the Moderate Resolution Imaging Spectroradiometer (MODIS) operational (Collection 4 and earlier) cloud products; and the surface is assumed to be Lambertian with an albedo of 0.03. Furthermore, error analyses pertaining to the inference of the effective particle sizes and optical thicknesses of mixed-phase clouds are performed. Errors are calculated with respect to the assumption of a cloud containing solely liquid or ice phase particles. The analyses suggest that the effective particle size inferred for a mixed-phase cloud can be underestimated (or overestimated) if pure liquid phase (or pure ice phase) is assumed for the cloud, whereas the corresponding cloud optical thickness can be overestimated (or underestimated).

Sampling the structure and chemical order in assemblies of ferromagnetic nanoparticles by nuclear magnetic resonance

PubMed Central

Liu, Yuefeng; Luo, Jingjie; Shin, Yooleemi; Moldovan, Simona; Ersen, Ovidiu; Hébraud, Anne; Schlatter, Guy; Pham-Huu, Cuong; Meny, Christian

2016-01-01

Assemblies of nanoparticles are studied in many research fields from physics to medicine. However, as it is often difficult to produce mono-dispersed particles, investigating the key parameters enhancing their efficiency is blurred by wide size distributions. Indeed, near-field methods analyse a part of the sample that might not be representative of the full size distribution and macroscopic methods give average information including all particle sizes. Here, we introduce temperature differential ferromagnetic nuclear resonance spectra that allow sampling the crystallographic structure, the chemical composition and the chemical order of non-interacting ferromagnetic nanoparticles for specific size ranges within their size distribution. The method is applied to cobalt nanoparticles for catalysis and allows extracting the size effect from the crystallographic structure effect on their catalytic activity. It also allows sampling of the chemical composition and chemical order within the size distribution of alloyed nanoparticles and can thus be useful in many research fields. PMID:27156575

The predictors of chemistry achievement of 12th grade students in secondary schools in the United Arab Emirates

NASA Astrophysics Data System (ADS)

Khalaf, Ali Khalfan

2000-10-01

The purpose of this study is to explore variables related to chemistry achievement of 12th grade science students in the United Arab Emirates (UAE). The focus is to identify student, teacher, and school variables that predict chemistry achievement. The analysis sample included 204 males and 252 females in 66 classes in 60 schools from 10 districts or bureaus of education in the UAE. Thirty-two male and 33 female chemistry teachers and 60 school principals were included. The Khalaf Chemistry Achievement Test, GALT, the Student Questionnaire, Teacher Questionnaire, and School Information Questionnaire were administered. Descriptive statistics, correlations, analyses of variance, factor analysis, and stepwise multiple linear regression analyses were done. The results indicate that demographic, home environment, prior knowledge, scholastic ability, attitudes and perceptions related to chemistry and science, and student perception of instructional practices variables correlated with student chemistry achievement. The amount of help teachers received from the supervisor, class size, and courses in geology were teacher variables that correlated with class chemistry achievement. Nine school variables involving school, division, and class sizes correlated with school chemistry achievement. Analyses of variance revealed significant interaction effects: district by school size and district by student gender. In two districts, students in small schools achieved better than those in large schools. Generally female students achieved equal to or better than males. Three factors from the factor analysis: School Size, Prior Student Achievement, and Student Perception of Teacher Effectiveness, correlated with school chemistry achievement. The results of the multiple linear regression indicated that the factors of Prior Student Achievement, Student Perception of Teacher Effectiveness, and Teacher Experience and Expertise accounted for 45% of the variance in school chemistry achievement. Results indicate that the strongest predictors of chemistry achievement are prior achievement in science, Arabic language, and mathematics; student perception of teacher effectiveness; and teacher experience and expertise. Females tend to achieve better in chemistry than males. No nationality differences were found and the relationship of school size to chemistry achievement was inconclusive. Recommendations related to chemistry and science are presented. These include curriculum, school practice, teacher professional development, and future research.

Researchers’ Intuitions About Power in Psychological Research

PubMed Central

Bakker, Marjan; Hartgerink, Chris H. J.; Wicherts, Jelte M.; van der Maas, Han L. J.

2016-01-01

Many psychology studies are statistically underpowered. In part, this may be because many researchers rely on intuition, rules of thumb, and prior practice (along with practical considerations) to determine the number of subjects to test. In Study 1, we surveyed 291 published research psychologists and found large discrepancies between their reports of their preferred amount of power and the actual power of their studies (calculated from their reported typical cell size, typical effect size, and acceptable alpha). Furthermore, in Study 2, 89% of the 214 respondents overestimated the power of specific research designs with a small expected effect size, and 95% underestimated the sample size needed to obtain .80 power for detecting a small effect. Neither researchers’ experience nor their knowledge predicted the bias in their self-reported power intuitions. Because many respondents reported that they based their sample sizes on rules of thumb or common practice in the field, we recommend that researchers conduct and report formal power analyses for their studies. PMID:27354203

Researchers' Intuitions About Power in Psychological Research.

PubMed

Bakker, Marjan; Hartgerink, Chris H J; Wicherts, Jelte M; van der Maas, Han L J

2016-08-01

Many psychology studies are statistically underpowered. In part, this may be because many researchers rely on intuition, rules of thumb, and prior practice (along with practical considerations) to determine the number of subjects to test. In Study 1, we surveyed 291 published research psychologists and found large discrepancies between their reports of their preferred amount of power and the actual power of their studies (calculated from their reported typical cell size, typical effect size, and acceptable alpha). Furthermore, in Study 2, 89% of the 214 respondents overestimated the power of specific research designs with a small expected effect size, and 95% underestimated the sample size needed to obtain .80 power for detecting a small effect. Neither researchers' experience nor their knowledge predicted the bias in their self-reported power intuitions. Because many respondents reported that they based their sample sizes on rules of thumb or common practice in the field, we recommend that researchers conduct and report formal power analyses for their studies. © The Author(s) 2016.

Effectiveness of psychological and/or educational interventions to prevent the onset of episodes of depression: A systematic review of systematic reviews and meta-analyses.

PubMed

Bellón, Juan Ángel; Moreno-Peral, Patricia; Motrico, Emma; Rodríguez-Morejón, Alberto; Fernández, Ana; Serrano-Blanco, Antoni; Zabaleta-del-Olmo, Edurne; Conejo-Cerón, Sonia

2015-07-01

To determine the effectiveness of psychological and/or educational interventions to prevent the onset of episodes of depression. Systematic review of systematic reviews and meta-analyses (SR/MA). We searched PubMed, PsycINFO, Cochrane Database of Systematic Reviews, OpenGrey, and PROSPERO from their inception until February 2014. Two reviewers independently evaluated the eligibility criteria of all SR/MA, abstracted data, and determined bias risk (AMSTAR). Twelve SR/MA (156 non-repeated trials and 56,158 participants) were included. Of these, 142 (91%) were randomized-controlled, 13 (8.3%) controlled trials, and 1 (0.6%) had no control group. Five SR/MA focused on children and adolescents, four on specific populations (women after childbirth, of low socioeconomic status, or unfavorable circumstances; patients with severe traumatic physical injuries or stroke) and three addressed the general population. Nine (75%) SR/MA concluded that interventions to prevent depression were effective. Of the 156 trials, 137 (87.8%) reported some kind of effect size calculation. Effect sizes were small in 45 (32.8%), medium in 26 (19.1%), and large in 25 (18.2%) trials; 41 (29.9%) trials were not effective. Of the 141 trials for which follow-up periods were available, only 34 (24.1%) exceeded 12 months. Psychological and/or educational interventions to prevent onset of episodes of depression were effective, although most had small or medium effect sizes. Copyright © 2014. Published by Elsevier Inc.

SAS Code for Calculating Intraclass Correlation Coefficients and Effect Size Benchmarks for Site-Randomized Education Experiments

ERIC Educational Resources Information Center

Brandon, Paul R.; Harrison, George M.; Lawton, Brian E.

2013-01-01

When evaluators plan site-randomized experiments, they must conduct the appropriate statistical power analyses. These analyses are most likely to be valid when they are based on data from the jurisdictions in which the studies are to be conducted. In this method note, we provide software code, in the form of a SAS macro, for producing statistical…

A New Material Mapping Procedure for Quantitative Computed Tomography-Based, Continuum Finite Element Analyses of the Vertebra

PubMed Central

Unnikrishnan, Ginu U.; Morgan, Elise F.

2011-01-01

Inaccuracies in the estimation of material properties and errors in the assignment of these properties into finite element models limit the reliability, accuracy, and precision of quantitative computed tomography (QCT)-based finite element analyses of the vertebra. In this work, a new mesh-independent, material mapping procedure was developed to improve the quality of predictions of vertebral mechanical behavior from QCT-based finite element models. In this procedure, an intermediate step, called the material block model, was introduced to determine the distribution of material properties based on bone mineral density, and these properties were then mapped onto the finite element mesh. A sensitivity study was first conducted on a calibration phantom to understand the influence of the size of the material blocks on the computed bone mineral density. It was observed that varying the material block size produced only marginal changes in the predictions of mineral density. Finite element (FE) analyses were then conducted on a square column-shaped region of the vertebra and also on the entire vertebra in order to study the effect of material block size on the FE-derived outcomes. The predicted values of stiffness for the column and the vertebra decreased with decreasing block size. When these results were compared to those of a mesh convergence analysis, it was found that the influence of element size on vertebral stiffness was less than that of the material block size. This mapping procedure allows the material properties in a finite element study to be determined based on the block size required for an accurate representation of the material field, while the size of the finite elements can be selected independently and based on the required numerical accuracy of the finite element solution. The mesh-independent, material mapping procedure developed in this study could be particularly helpful in improving the accuracy of finite element analyses of vertebroplasty and spine metastases, as these analyses typically require mesh refinement at the interfaces between distinct materials. Moreover, the mapping procedure is not specific to the vertebra and could thus be applied to many other anatomic sites. PMID:21823740

Unemployment Impairs Mental Health: Meta-Analyses

ERIC Educational Resources Information Center

Paul, Karsten I.; Moser, Klaus

2009-01-01

The effect of unemployment on mental health was examined with meta-analytic methods across 237 cross-sectional and 87 longitudinal studies. The average overall effect size was d = 0.51 with unemployed persons showing more distress than employed persons. A significant difference was found for several indicator variables of mental health (mixed…

Meta-analysis of free-response studies, 1992-2008: assessing the noise reduction model in parapsychology.

PubMed

Storm, Lance; Tressoldi, Patrizio E; Di Risio, Lorenzo

2010-07-01

We report the results of meta-analyses on 3 types of free-response study: (a) ganzfeld (a technique that enhances a communication anomaly referred to as "psi"); (b) nonganzfeld noise reduction using alleged psi-enhancing techniques such as dream psi, meditation, relaxation, or hypnosis; and (c) standard free response (nonganzfeld, no noise reduction). For the period 1997-2008, a homogeneous data set of 29 ganzfeld studies yielded a mean effect size of 0.142 (Stouffer Z = 5.48, p = 2.13 x 10(-8)). A homogeneous nonganzfeld noise reduction data set of 16 studies yielded a mean effect size of 0.110 (Stouffer Z = 3.35, p = 2.08 x 10(-4)), and a homogeneous data set of 14 standard free-response studies produced a weak negative mean effect size of -0.029 (Stouffer Z = -2.29, p = .989). The mean effect size value of the ganzfeld database was significantly higher than the mean effect size of the standard free-response database but was not higher than the effect size of the nonganzfeld noise reduction database [corrected].We also found that selected participants (believers in the paranormal, meditators, etc.) had a performance advantage over unselected participants, but only if they were in the ganzfeld condition.

Effect Size for Token Economy Use in Contemporary Classroom Settings: A Meta-Analysis of Single-Case Research

ERIC Educational Resources Information Center

Soares, Denise A.; Harrison, Judith R.; Vannest, Kimberly J.; McClelland, Susan S.

2016-01-01

Recent meta-analyses of the effectiveness of token economies (TEs) report insufficient quality in the research or mixed effects in the results. This study examines the contemporary (post-Public Law 94-142) peer-reviewed published single-case research evaluating the effectiveness of TEs. The results are stratified across quality of demonstrated…

Understanding effects in reviews of implementation interventions using the Theoretical Domains Framework.

PubMed

Little, Elizabeth A; Presseau, Justin; Eccles, Martin P

2015-06-17

Behavioural theory can be used to better understand the effects of behaviour change interventions targeting healthcare professional behaviour to improve quality of care. However, the explicit use of theory is rarely reported despite interventions inevitably involving at least an implicit idea of what factors to target to implement change. There is a quality of care gap in the post-fracture investigation (bone mineral density (BMD) scanning) and management (bisphosphonate prescription) of patients at risk of osteoporosis. We aimed to use the Theoretical Domains Framework (TDF) within a systematic review of interventions to improve quality of care in post-fracture investigation. Our objectives were to explore which theoretical factors the interventions in the review may have been targeting and how this might be related to the size of the effect on rates of BMD scanning and osteoporosis treatment with bisphosphonate medication. A behavioural scientist and a clinician independently coded TDF domains in intervention and control groups. Quantitative analyses explored the relationship between intervention effect size and total number of domains targeted, and as number of different domains targeted. Nine randomised controlled trials (RCTs) (10 interventions) were analysed. The five theoretical domains most frequently coded as being targeted by the interventions in the review included "memory, attention and decision processes", "knowledge", "environmental context and resources", "social influences" and "beliefs about consequences". Each intervention targeted a combination of at least four of these five domains. Analyses identified an inverse relationship between both number of times and number of different domains coded and the effect size for BMD scanning but not for bisphosphonate prescription, suggesting that the more domains the intervention targeted, the lower the observed effect size. When explicit use of theory to inform interventions is absent, it is possible to retrospectively identify the likely targeted factors using theoretical frameworks such as the TDF. In osteoporosis management, this suggested that several likely determinants of healthcare professional behaviour appear not yet to have been considered in implementation interventions. This approach may serve as a useful basis for using theory-based frameworks such as the TDF to retrospectively identify targeted factors within systematic reviews of implementation interventions in other implementation contexts.

The Effects of School-Based Interventions for Attention Deficit Hyperactivity Disorder: A Meta-Analysis 1996-2010

ERIC Educational Resources Information Center

DuPaul, George J.; Eckert, Tanya L.; Vilardo, Brigid

2012-01-01

A meta-analysis evaluating the effects of school-based interventions for students with attention deficit hyperactivity disorder was conducted by examining 60 outcome studies between 1996 and 2010 that yielded 85 effect sizes. Separate analyses were performed for studies employing between-subjects, within- subjects, and single-subject experimental…

Reallocation in modal aerosol models: impacts on predicting aerosol radiative effects

NASA Astrophysics Data System (ADS)

Korhola, T.; Kokkola, H.; Korhonen, H.; Partanen, A.-I.; Laaksonen, A.; Lehtinen, K. E. J.; Romakkaniemi, S.

2013-08-01

In atmospheric modelling applications the aerosol particle size distribution is commonly represented by modal approach, in which particles in different size ranges are described with log-normal modes within predetermined size ranges. Such method includes numerical reallocation of particles from a mode to another for example during particle growth, leading to potentially artificial changes in the aerosol size distribution. In this study we analysed how this reallocation affects climatologically relevant parameters: cloud droplet number concentration, aerosol-cloud interaction coefficient and light extinction coefficient. We compared these parameters between a modal model with and without reallocation routines, and a high resolution sectional model that was considered as a reference model. We analysed the relative differences of the parameters in different experiments that were designed to cover a wide range of dynamic aerosol processes occurring in the atmosphere. According to our results, limiting the allowed size ranges of the modes and the following numerical remapping of the distribution by reallocation, leads on average to underestimation of cloud droplet number concentration (up to 100%) and overestimation of light extinction (up to 20%). The analysis of aerosol first indirect effect is more complicated as the ACI parameter can be either over- or underestimated by the reallocating model, depending on the conditions. However, for example in the case of atmospheric new particle formation events followed by rapid particle growth, the reallocation can cause around average 10% overestimation of the ACI parameter. Thus it is shown that the reallocation affects the ability of a model to estimate aerosol climate effects accurately, and this should be taken into account when using and developing aerosol models.

Methods to increase reproducibility in differential gene expression via meta-analysis

PubMed Central

Sweeney, Timothy E.; Haynes, Winston A.; Vallania, Francesco; Ioannidis, John P.; Khatri, Purvesh

2017-01-01

Findings from clinical and biological studies are often not reproducible when tested in independent cohorts. Due to the testing of a large number of hypotheses and relatively small sample sizes, results from whole-genome expression studies in particular are often not reproducible. Compared to single-study analysis, gene expression meta-analysis can improve reproducibility by integrating data from multiple studies. However, there are multiple choices in designing and carrying out a meta-analysis. Yet, clear guidelines on best practices are scarce. Here, we hypothesized that studying subsets of very large meta-analyses would allow for systematic identification of best practices to improve reproducibility. We therefore constructed three very large gene expression meta-analyses from clinical samples, and then examined meta-analyses of subsets of the datasets (all combinations of datasets with up to N/2 samples and K/2 datasets) compared to a ‘silver standard’ of differentially expressed genes found in the entire cohort. We tested three random-effects meta-analysis models using this procedure. We showed relatively greater reproducibility with more-stringent effect size thresholds with relaxed significance thresholds; relatively lower reproducibility when imposing extraneous constraints on residual heterogeneity; and an underestimation of actual false positive rate by Benjamini–Hochberg correction. In addition, multivariate regression showed that the accuracy of a meta-analysis increased significantly with more included datasets even when controlling for sample size. PMID:27634930

Tactile sensitivity of gloved hands in the cold operation.

PubMed

Geng, Q; Kuklane, K; Holmér, I

1997-11-01

In this study, tactile sensitivity of gloved hand in the cold operation has been investigated. The relations among physical properties of protective gloves and hand tactile sensitivity and cold protection were also analysed both objectively and subjectively. Subjects with various gloves participated in the experimental study during cold exposure at different ambient temperatures of -12 degrees C and -25 degrees C. Tactual performance was measured using an identification task with various sizes of objects over the percentage of misjudgment. Forearm, hand and finger skin temperatures were also recorded throughout. The experimental data were analysed using analysis of variance (ANOVA) model and the Tukey's multiple range test. The results obtained indicated that the tactual performance was affected both by gloves and by hands/fingers cooling. Effect of object size on the tactile discrimination was significant and the misjudgment increased when similar sizes of objects were identified, especially at -25 degrees C.

Strategies for Improving Power in School-Randomized Studies of Professional Development.

PubMed

Kelcey, Ben; Phelps, Geoffrey

2013-12-01

Group-randomized designs are well suited for studies of professional development because they can accommodate programs that are delivered to intact groups (e.g., schools), the collaborative nature of professional development, and extant teacher/school assignments. Though group designs may be theoretically favorable, prior evidence has suggested that they may be challenging to conduct in professional development studies because well-powered designs will typically require large sample sizes or expect large effect sizes. Using teacher knowledge outcomes in mathematics, we investigated when and the extent to which there is evidence that covariance adjustment on a pretest, teacher certification, or demographic covariates can reduce the sample size necessary to achieve reasonable power. Our analyses drew on multilevel models and outcomes in five different content areas for over 4,000 teachers and 2,000 schools. Using these estimates, we assessed the minimum detectable effect sizes for several school-randomized designs with and without covariance adjustment. The analyses suggested that teachers' knowledge is substantially clustered within schools in each of the five content areas and that covariance adjustment for a pretest or, to a lesser extent, teacher certification, has the potential to transform designs that are unreasonably large for professional development studies into viable studies. © The Author(s) 2014.

Demographic change and carbon dioxide emissions.

PubMed

O'Neill, Brian C; Liddle, Brant; Jiang, Leiwen; Smith, Kirk R; Pachauri, Shonali; Dalton, Michael; Fuchs, Regina

2012-07-14

Relations between demographic change and emissions of the major greenhouse gas carbon dioxide (CO(2)) have been studied from different perspectives, but most projections of future emissions only partly take demographic influences into account. We review two types of evidence for how CO(2) emissions from the use of fossil fuels are affected by demographic factors such as population growth or decline, ageing, urbanisation, and changes in household size. First, empirical analyses of historical trends tend to show that CO(2) emissions from energy use respond almost proportionately to changes in population size and that ageing and urbanisation have less than proportional but statistically significant effects. Second, scenario analyses show that alternative population growth paths could have substantial effects on global emissions of CO(2) several decades from now, and that ageing and urbanisation can have important effects in particular world regions. These results imply that policies that slow population growth would probably also have climate-related benefits. Copyright © 2012 Elsevier Ltd. All rights reserved.

Conducting Meta-Analyses Based on p Values

PubMed Central

van Aert, Robbie C. M.; Wicherts, Jelte M.; van Assen, Marcel A. L. M.

2016-01-01

Because of overwhelming evidence of publication bias in psychology, techniques to correct meta-analytic estimates for such bias are greatly needed. The methodology on which the p-uniform and p-curve methods are based has great promise for providing accurate meta-analytic estimates in the presence of publication bias. However, in this article, we show that in some situations, p-curve behaves erratically, whereas p-uniform may yield implausible estimates of negative effect size. Moreover, we show that (and explain why) p-curve and p-uniform result in overestimation of effect size under moderate-to-large heterogeneity and may yield unpredictable bias when researchers employ p-hacking. We offer hands-on recommendations on applying and interpreting results of meta-analyses in general and p-uniform and p-curve in particular. Both methods as well as traditional methods are applied to a meta-analysis on the effect of weight on judgments of importance. We offer guidance for applying p-uniform or p-curve using R and a user-friendly web application for applying p-uniform. PMID:27694466

The influence of the design matrix on treatment effect estimates in the quantitative analyses of single-subject experimental design research.

PubMed

Moeyaert, Mariola; Ugille, Maaike; Ferron, John M; Beretvas, S Natasha; Van den Noortgate, Wim

2014-09-01

The quantitative methods for analyzing single-subject experimental data have expanded during the last decade, including the use of regression models to statistically analyze the data, but still a lot of questions remain. One question is how to specify predictors in a regression model to account for the specifics of the design and estimate the effect size of interest. These quantitative effect sizes are used in retrospective analyses and allow synthesis of single-subject experimental study results which is informative for evidence-based decision making, research and theory building, and policy discussions. We discuss different design matrices that can be used for the most common single-subject experimental designs (SSEDs), namely, the multiple-baseline designs, reversal designs, and alternating treatment designs, and provide empirical illustrations. The purpose of this article is to guide single-subject experimental data analysts interested in analyzing and meta-analyzing SSED data. © The Author(s) 2014.

Maximizing Sensitivity of the Psychomotor Vigilance Test (PVT) to Sleep Loss

PubMed Central

Basner, Mathias; Dinges, David F.

2011-01-01

Study Objectives: The psychomotor vigilance test (PVT) is among the most widely used measures of behavioral alertness, but there is large variation among published studies in PVT performance outcomes and test durations. To promote standardization of the PVT and increase its sensitivity and specificity to sleep loss, we determined PVT metrics and task durations that optimally discriminated sleep deprived subjects from alert subjects. Design: Repeated-measures experiments involving 10-min PVT assessments every 2 h across both acute total sleep deprivation (TSD) and 5 days of chronic partial sleep deprivation (PSD). Setting: Controlled laboratory environment. Participants: 74 healthy subjects (34 female), aged 22–45 years. Interventions: TSD experiment involving 33 h awake (N = 31 subjects) and a PSD experiment involving 5 nights of 4 h time in bed (N = 43 subjects). Measurements and Results: In a paired t-test paradigm and for both TSD and PSD, effect sizes of 10 different PVT performance outcomes were calculated. Effect sizes were high for both TSD (1.59–1.94) and PSD (0.88–1.21) for PVT metrics related to lapses and to measures of psychomotor speed, i.e., mean 1/RT (response time) and mean slowest 10% 1/RT. In contrast, PVT mean and median RT outcomes scored low to moderate effect sizes influenced by extreme values. Analyses facilitating only portions of the full 10-min PVT indicated that for some outcomes, high effect sizes could be achieved with PVT durations considerably shorter than 10 min, although metrics involving lapses seemed to profit from longer test durations in TSD. Conclusions: Due to their superior conceptual and statistical properties and high sensitivity to sleep deprivation, metrics involving response speed and lapses should be considered primary outcomes for the 10-min PVT. In contrast, PVT mean and median metrics, which are among the most widely used outcomes, should be avoided as primary measures of alertness. Our analyses also suggest that some shorter-duration PVT versions may be sensitive to sleep loss, depending on the outcome variable selected, although this will need to be confirmed in comparative analyses of separate duration versions of the PVT. Using both sensitive PVT metrics and optimal test durations maximizes the sensitivity of the PVT to sleep loss and therefore potentially decreases the sample size needed to detect the same neurobehavioral deficit. We propose criteria to better standardize the 10-min PVT and facilitate between-study comparisons and meta-analyses. Citation: Basner M; Dinges DF. Maximizing sensitivity of the psychomotor vigilance test (PVT) to sleep loss. SLEEP 2011;34(5):581-591. PMID:21532951

Examining Ecological Constraints on the Intergenerational Transmission of Attachment Via Individual Participant Data Meta-analysis.

PubMed

Verhage, Marije L; Fearon, R M Pasco; Schuengel, Carlo; van IJzendoorn, Marinus H; Bakermans-Kranenburg, Marian J; Madigan, Sheri; Roisman, Glenn I; Oosterman, Mirjam; Behrens, Kazuko Y; Wong, Maria S; Mangelsdorf, Sarah; Priddis, Lynn E; Brisch, Karl-Heinz

2018-05-09

Parents' attachment representations and child-parent attachment have been shown to be associated, but these associations vary across populations (Verhage et al., 2016). The current study examined whether ecological factors may explain variability in the strength of intergenerational transmission of attachment, using individual participant data (IPD) meta-analysis. Analyses on 4,396 parent-child dyads (58 studies, child age 11-96 months) revealed a combined effect size of r = .29. IPD meta-analyses revealed that effect sizes for the transmission of autonomous-secure representations to secure attachments were weaker under risk conditions and weaker in adolescent parent-child dyads, whereas transmission was stronger for older children. Findings support the ecological constraints hypothesis on attachment transmission. Implications for attachment theory and the use of IPD meta-analysis are discussed. © 2018 The Authors. Child Development published by Wiley Periodicals, Inc. on behalf of Society for Research in Child Development.

Effect of element size on the solution accuracies of finite-element heat transfer and thermal stress analyses of space shuttle orbiter

NASA Technical Reports Server (NTRS)

Ko, William L.; Olona, Timothy

1987-01-01

The effect of element size on the solution accuracies of finite-element heat transfer and thermal stress analyses of space shuttle orbiter was investigated. Several structural performance and resizing (SPAR) thermal models and NASA structural analysis (NASTRAN) structural models were set up for the orbiter wing midspan bay 3. The thermal model was found to be the one that determines the limit of finite-element fineness because of the limitation of computational core space required for the radiation view factor calculations. The thermal stresses were found to be extremely sensitive to a slight variation of structural temperature distributions. The minimum degree of element fineness required for the thermal model to yield reasonably accurate solutions was established. The radiation view factor computation time was found to be insignificant compared with the total computer time required for the SPAR transient heat transfer analysis.

Deconvoluting effects of vine and soil properties on grape berry composition.

PubMed

Zerihun, Ayalsew; McClymont, Lexie; Lanyon, Dean; Goodwin, Ian; Gibberd, Mark

2015-01-01

Grape berry composition is influenced by several factors including grapevine and soil properties and their interactions. Understanding how these factors interact to determine berry composition is integral to producing berries with desired composition. Here we used extensive spatio-temporal data to identify significant vine and soil features that influence Shiraz berry composition. The concentrations of berry flavonoids (anthocyanins, tannin and total phenolics), total soluble solids and pH were typically negatively associated with canopy, crop and berry size factors whereas titratable acidity was positively associated. The strengths of the associations, however, were generally greater with the crop and berry size factors than with the canopy size factor. The analyses also resolved separate influences of berry and crop size on berry composition. Soil properties had significant influences on berry composition; however, when influences of soil factors on vine-attributes were accounted for, the apparent effects of soil factors on berry composition were largely non-existent. At each site, variations in berry composition were more strongly associated with crop and berry size than with canopy size factors. Apparent influences of soil properties on berry composition are indirect, being mediated via their effects on vine attributes (canopy, crop and berry sizes). © 2014 Society of Chemical Industry.

Sample size considerations when groups are the appropriate unit of analyses

PubMed Central

Sadler, Georgia Robins; Ko, Celine Marie; Alisangco, Jennifer; Rosbrook, Bradley P.; Miller, Eric; Fullerton, Judith

2007-01-01

This paper discusses issues to be considered by nurse researchers when groups should be used as a unit of randomization. Advantages and disadvantages are presented, with statistical calculations needed to determine effective sample size. Examples of these concepts are presented using data from the Black Cosmetologists Promoting Health Program. Different hypothetical scenarios and their impact on sample size are presented. Given the complexity of calculating sample size when using groups as a unit of randomization, it’s advantageous for researchers to work closely with statisticians when designing and implementing studies that anticipate the use of groups as the unit of randomization. PMID:17693219

Use of randomised controlled trials for producing cost-effectiveness evidence: potential impact of design choices on sample size and study duration.

PubMed

Backhouse, Martin E

2002-01-01

A number of approaches to conducting economic evaluations could be adopted. However, some decision makers have a preference for wholly stochastic cost-effectiveness analyses, particularly if the sampled data are derived from randomised controlled trials (RCTs). Formal requirements for cost-effectiveness evidence have heightened concerns in the pharmaceutical industry that development costs and times might be increased if formal requirements increase the number, duration or costs of RCTs. Whether this proves to be the case or not will depend upon the timing, nature and extent of the cost-effectiveness evidence required. To illustrate how different requirements for wholly stochastic cost-effectiveness evidence could have a significant impact on two of the major determinants of new drug development costs and times, namely RCT sample size and study duration. Using data collected prospectively in a clinical evaluation, sample sizes were calculated for a number of hypothetical cost-effectiveness study design scenarios. The results were compared with a baseline clinical trial design. The sample sizes required for the cost-effectiveness study scenarios were mostly larger than those for the baseline clinical trial design. Circumstances can be such that a wholly stochastic cost-effectiveness analysis might not be a practical proposition even though its clinical counterpart is. In such situations, alternative research methodologies would be required. For wholly stochastic cost-effectiveness analyses, the importance of prior specification of the different components of study design is emphasised. However, it is doubtful whether all the information necessary for doing this will typically be available when product registration trials are being designed. Formal requirements for wholly stochastic cost-effectiveness evidence based on the standard frequentist paradigm have the potential to increase the size, duration and number of RCTs significantly and hence the costs and timelines associated with new product development. Moreover, it is possible to envisage situations where such an approach would be impossible to adopt. Clearly, further research is required into the issue of how to appraise the economic consequences of alternative economic evaluation research strategies.

The Efficacy, Safety and Applications of Medical Hypnosis.

PubMed

Häuser, Winfried; Hagl, Maria; Schmierer, Albrecht; Hansen, Ernil

2016-04-29

The efficacy and safety of hypnotic techniques in somatic medicine, known as medical hypnosis, have not been supported to date by adequate scientific evidence. We systematically reviewed meta-analyses of randomized controlled trials (RCTs) of medical hypnosis. Relevant publications (January 2005 to June 2015) were sought in the Cochrane databases CDSR and DARE, and in PubMed. Meta-analyses involving at least 400 patients were included in the present analysis. Their methodological quality was assessed with AMSTAR (A Measurement Tool to Assess Systematic Reviews). An additional search was carried out in the CENTRAL and PubMed databases for RCTs of waking suggestion (therapeutic suggestion without formal trance induction) in somatic medicine. Out of the 391 publications retrieved, five were reports of metaanalyses that met our inclusion criteria. One of these meta-analyses was of high methodological quality; three were of moderate quality, and one was of poor quality. Hypnosis was superior to controls with respect to the reduction of pain and emotional stress during medical interventions (34 RCTs, 2597 patients) as well as the reduction of irritable bowel symptoms (8 RCTs, 464 patients). Two meta-analyses revealed no differences between hypnosis and control treatment with respect to the side effects and safety of treatment. The effect size of hypnosis on emotional stress during medical interventions was low in one meta-analysis, moderate in one, and high in one. The effect size on pain during medical interventions was low. Five RCTs indicated that waking suggestion is effective in medical procedures. Medical hypnosis is a safe and effective complementary technique for use in medical procedures and in the treatment of irritable bowel syndrome. Waking suggestions can be a component of effective doctor-patient communication in routine clinical situations.

Bias from historical control groups used in orthodontic research: a meta-epidemiological study.

PubMed

Papageorgiou, Spyridon N; Koretsi, Vasiliki; Jäger, Andreas

2017-02-01

The validity of meta-analysis is dependent upon the quality of included studies. Here, we investigated whether the design of untreated control groups (i.e. source and timing of data collection) influences the results of clinical trials in orthodontic research. This meta-epidemiological study used unrestricted literature searching for meta-analyses in orthodontics including clinical trials with untreated control groups. Differences in standardized mean differences (ΔSMD) and their 95% confidence intervals (CIs) were calculated according to the untreated control group through multivariable random-effects meta-regression controlling for nature of the interventional group and study sample size. Effects were pooled with random-effects synthesis, followed by mixed-effect subgroup and sensitivity analyses. Studies with historical control groups reported deflated treatment effects compared to studies with concurrent control groups (13 meta-analyses; ΔSMD = -0.31; 95% CI = -0.53, -0.10; P = 0.004). Significant differences were found according to the type of historical control group (based either on growth study or clinical archive; 11 meta-analyses; ΔSMD = 0.40; 95% CI = 0.21, 0.59; P < 0.001). The use of historical control groups in orthodontic clinical research was associated with deflation of treatment effects, which was independent from whether the interventional group was prospective or retrospective and from the study's sample size. Caution is warranted when interpreting clinical studies with historical untreated control groups or when interpreting systematic reviews that include such studies. PROSPERO (CRD42015024179). None. © The Author 2016. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com.

The effects of delay duration on visual working memory for orientation.

PubMed

Shin, Hongsup; Zou, Qijia; Ma, Wei Ji

2017-12-01

We used a delayed-estimation paradigm to characterize the joint effects of set size (one, two, four, or six) and delay duration (1, 2, 3, or 6 s) on visual working memory for orientation. We conducted two experiments: one with delay durations blocked, another with delay durations interleaved. As dependent variables, we examined four model-free metrics of dispersion as well as precision estimates in four simple models. We tested for effects of delay time using analyses of variance, linear regressions, and nested model comparisons. We found significant effects of set size and delay duration on both model-free and model-based measures of dispersion. However, the effect of delay duration was much weaker than that of set size, dependent on the analysis method, and apparent in only a minority of subjects. The highest forgetting slope found in either experiment at any set size was a modest 1.14°/s. As secondary results, we found a low rate of nontarget reports, and significant estimation biases towards oblique orientations (but no dependence of their magnitude on either set size or delay duration). Relative stability of working memory even at higher set sizes is consistent with earlier results for motion direction and spatial frequency. We compare with a recent study that performed a very similar experiment.

Effect of font size, italics, and colour count on web usability.

PubMed

Bhatia, Sanjiv K; Samal, Ashok; Rajan, Nithin; Kiviniemi, Marc T

2011-04-01

Web usability measures the ease of use of a website. This study attempts to find the effect of three factors - font size, italics, and colour count - on web usability. The study was performed using a set of tasks and developing a survey questionnaire. We performed the study using a set of human subjects, selected from the undergraduate students taking courses in psychology. The data computed from the tasks and survey questionnaire were statistically analysed to find if there was any effect of font size, italics, and colour count on the three web usability dimensions. We found that for the student population considered, there was no significant effect of font size on usability. However, the manipulation of italics and colour count did influence some aspects of usability. The subjects performed better for pages with no italics and high italics compared to moderate italics. The subjects rated the pages that contained only one colour higher than the web pages with four or six colours. This research will help web developers better understand the effect of font size, italics, and colour count on web usability in general, and for young adults, in particular.

Effect of font size, italics, and colour count on web usability

PubMed Central

Samal, Ashok; Rajan, Nithin; Kiviniemi, Marc T.

2013-01-01

Web usability measures the ease of use of a website. This study attempts to find the effect of three factors – font size, italics, and colour count – on web usability. The study was performed using a set of tasks and developing a survey questionnaire. We performed the study using a set of human subjects, selected from the undergraduate students taking courses in psychology. The data computed from the tasks and survey questionnaire were statistically analysed to find if there was any effect of font size, italics, and colour count on the three web usability dimensions. We found that for the student population considered, there was no significant effect of font size on usability. However, the manipulation of italics and colour count did influence some aspects of usability. The subjects performed better for pages with no italics and high italics compared to moderate italics. The subjects rated the pages that contained only one colour higher than the web pages with four or six colours. This research will help web developers better understand the effect of font size, italics, and colour count on web usability in general, and for young adults, in particular. PMID:24358055

Sample size requirements for indirect association studies of gene-environment interactions (G x E).

PubMed

Hein, Rebecca; Beckmann, Lars; Chang-Claude, Jenny

2008-04-01

Association studies accounting for gene-environment interactions (G x E) may be useful for detecting genetic effects. Although current technology enables very dense marker spacing in genetic association studies, the true disease variants may not be genotyped. Thus, causal genes are searched for by indirect association using genetic markers in linkage disequilibrium (LD) with the true disease variants. Sample sizes needed to detect G x E effects in indirect case-control association studies depend on the true genetic main effects, disease allele frequencies, whether marker and disease allele frequencies match, LD between loci, main effects and prevalence of environmental exposures, and the magnitude of interactions. We explored variables influencing sample sizes needed to detect G x E, compared these sample sizes with those required to detect genetic marginal effects, and provide an algorithm for power and sample size estimations. Required sample sizes may be heavily inflated if LD between marker and disease loci decreases. More than 10,000 case-control pairs may be required to detect G x E. However, given weak true genetic main effects, moderate prevalence of environmental exposures, as well as strong interactions, G x E effects may be detected with smaller sample sizes than those needed for the detection of genetic marginal effects. Moreover, in this scenario, rare disease variants may only be detectable when G x E is included in the analyses. Thus, the analysis of G x E appears to be an attractive option for the detection of weak genetic main effects of rare variants that may not be detectable in the analysis of genetic marginal effects only.

Effect of solvent and temperature on the size distribution of casein micelles measured by dynamic light scattering.

PubMed

Beliciu, C M; Moraru, C I

2009-05-01

The objectives of this study were to investigate the effect of the solvent on the accuracy of casein micelle particle size determination by dynamic light scattering (DLS) at different temperatures and to establish a clear protocol for these measurements. Dynamic light scattering analyses were performed at 6, 20, and 50 degrees C using a 90Plus Nanoparticle Size Analyzer (Brookhaven Instruments, Holtsville, NY). Raw and pasteurized skim milk were used as sources of casein micelles. Simulated milk ultrafiltrate, ultrafiltered water, and permeate obtained by ultrafiltration of skim milk using a 10-kDa cutoff membrane were used as solvents. The pH, ionic concentration, refractive index, and viscosity of all solvents were determined. The solvents were evaluated by DLS to ensure that they did not have a significant influence on the results of the particle size measurements. Experimental protocols were developed for accurate measurement of particle sizes in all solvents and experimental conditions. All measurements had good reproducibility, with coefficients of variation below 5%. Both the solvent and the temperature had a significant effect on the measured effective diameter of the casein micelles. When ultrafiltered permeate was used as a solvent, the particle size and polydispersity of casein micelles decreased as temperature increased. The effective diameter of casein micelles from raw skim milk diluted with ultrafiltered permeate was 176.4 +/- 5.3 nm at 6 degrees C, 177.4 +/- 1.9 nm at 20 degrees C, and 137.3 +/- 2.7 nm at 50 degrees C. This trend was justified by the increased strength of hydrophobic bonds with increasing temperature. Overall, the results of this study suggest that the most suitable solvent for the DLS analyses of casein micelles was casein-depleted ultrafiltered permeate. Dilution with water led to micelle dissociation, which significantly affected the DLS measurements, especially at 6 and 20 degrees C. Simulated milk ultrafiltrate seemed to give accurate results only at 20 degrees C. Results obtained in simulated milk ultrafiltrate at 6 degrees C could not be explained based on the known effects of temperature on the casein micelle, whereas at 50 degrees C, precipitation of amorphous calcium phosphate affected the DLS measurement.

Effect of brewing technique and particle size of the ground coffee on sensory profiling of brewed Dampit robusta coffee

NASA Astrophysics Data System (ADS)

Fibrianto, K.; Febryana, Y. R.; Wulandari, E. S.

2018-03-01

This study aimed to assess the effect of different brewing techniques with the use of appropriate particle size standard of Apresiocoffee cafe (Category 1) compared to the difference brewing techniques with the use of the same particle size (coarse) (Category 2) of the sensory attributes Dampit robusta coffee. Rate-All-That-Apply (RATA) method was applied in this study, and the data was analysed by ANOVA General Linier Model (GLM) on Minitab-16. The influence of brewing techniques (tubruk, French-press, drips, syphon) and type of particle size ground coffee (fine, medium, coarse) were sensorially observed. The result showed that only two attributes, including bitter taste, and astringent/rough-mouth-feel were affected by brewing techniques (p-value <0.05) as observed for brewed coarse coffee powder.

Meta-Analysis of Interventions for Basic Mathematics Computation in Single-Case Research

ERIC Educational Resources Information Center

Methe, Scott A.; Kilgus, Stephen P.; Neiman, Cheryl; Riley-Tillman, T. Chris

2012-01-01

This study examined interventions for addition and subtraction that were implemented through single-case design (SCD) research studies. We attempted to extend prior SCD meta-analyses by examining differences in effect sizes across several moderating variables and by including a novel index of effect, improvement rate difference (IRD). We also…

Safe and sensible preprocessing and baseline correction of pupil-size data.

PubMed

Mathôt, Sebastiaan; Fabius, Jasper; Van Heusden, Elle; Van der Stigchel, Stefan

2018-02-01

Measurement of pupil size (pupillometry) has recently gained renewed interest from psychologists, but there is little agreement on how pupil-size data is best analyzed. Here we focus on one aspect of pupillometric analyses: baseline correction, i.e., analyzing changes in pupil size relative to a baseline period. Baseline correction is useful in experiments that investigate the effect of some experimental manipulation on pupil size. In such experiments, baseline correction improves statistical power by taking into account random fluctuations in pupil size over time. However, we show that baseline correction can also distort data if unrealistically small pupil sizes are recorded during the baseline period, which can easily occur due to eye blinks, data loss, or other distortions. Divisive baseline correction (corrected pupil size = pupil size/baseline) is affected more strongly by such distortions than subtractive baseline correction (corrected pupil size = pupil size - baseline). We discuss the role of baseline correction as a part of preprocessing of pupillometric data, and make five recommendations: (1) before baseline correction, perform data preprocessing to mark missing and invalid data, but assume that some distortions will remain in the data; (2) use subtractive baseline correction; (3) visually compare your corrected and uncorrected data; (4) be wary of pupil-size effects that emerge faster than the latency of the pupillary response allows (within ±220 ms after the manipulation that induces the effect); and (5) remove trials on which baseline pupil size is unrealistically small (indicative of blinks and other distortions).

Retest effects in working memory capacity tests: A meta-analysis.

PubMed

Scharfen, Jana; Jansen, Katrin; Holling, Heinz

2018-06-15

The repeated administration of working memory capacity tests is common in clinical and research settings. For cognitive ability tests and different neuropsychological tests, meta-analyses have shown that they are prone to retest effects, which have to be accounted for when interpreting retest scores. Using a multilevel approach, this meta-analysis aims at showing the reproducibility of retest effects in working memory capacity tests for up to seven test administrations, and examines the impact of the length of the test-retest interval, test modality, equivalence of test forms and participant age on the size of retest effects. Furthermore, it is assessed whether the size of retest effects depends on the test paradigm. An extensive literature search revealed 234 effect sizes from 95 samples and 68 studies, in which healthy participants between 12 and 70 years repeatedly performed a working memory capacity test. Results yield a weighted average of g = 0.28 for retest effects from the first to the second test administration, and a significant increase in effect sizes was observed up to the fourth test administration. The length of the test-retest interval and publication year were found to moderate the size of retest effects. Retest effects differed between the paradigms of working memory capacity tests. These findings call for the development and use of appropriate experimental or statistical methods to address retest effects in working memory capacity tests.

In-situ micro bend testing of SiC and the effects of Ga+ ion damage

NASA Astrophysics Data System (ADS)

Robertson, S.; Doak, SS; Zhou, Z.; Wu, H.

2017-09-01

The Young’s modulus of 6H single crystal silicon carbide (SiC) was tested with micro cantilevers that had a range of cross-sectional dimensions with surfaces cleaned under different accelerating voltages of Ga+ beam. A clear size effect is seen with Young’s modulus decreasing as the cross-sectional area reduces. One of the possible reasons for such size effect is the Ga+ induced damage on all surfaces of the cantilever. Transmission electron microscopy (TEM) was used to analyse the degree of damage, and the measurements of damage is compared to predictions by SRIM irradiation simulation.

The Research of Tax Text Categorization based on Rough Set

NASA Astrophysics Data System (ADS)

Liu, Bin; Xu, Guang; Xu, Qian; Zhang, Nan

To solve the problem of effective of categorization of text data in taxation system, the paper analyses the text data and the size calculation of key issues first, then designs text categorization based on rough set model.

Size matters: a meta-analysis on the impact of hospital size on patient mortality.

PubMed

Fareed, Naleef

2012-06-01

This paper seeks to understand the relationship between hospital size and patient mortality. Patient mortality has been used by several studies in the health services research field as a proxy for measuring healthcare quality. A systematic review is conducted to identify studies that investigate the impact of hospital size on patient mortality. Using the findings of 21 effect sizes from 10 eligible studies, a meta-analysis is performed using a random effects model. Subgroup analyses using three factors--the measure used for hospital size, type of mortality measure used and whether mortality was adjusted or unadjusted--were utilised to investigate their moderating influence on the study's primary relationship. Results from this analysis indicate that big hospitals have lower odds of patient mortality versus small hospitals. Specifically, the probability of patient mortality in a big hospital, in reference to a small hospital, is 11% less. Subgroup analyses show that studies with unadjusted mortality rates have an even lower overall odds ratio of mortality versus studies with adjusted mortality rates. Aside from some limitations in data reporting, the findings of this paper support theoretical notions that big hospitals have lower mortality rates than small hospitals. Guidelines for better data reporting and future research are provided to further explore the phenomenon. Policy implications of this paper's findings are underscored and a sense of urgency is called for in an effort to help improve the state of a healthcare system that struggles with advancing healthcare quality. © 2012 The Author. International Journal of Evidence-Based Healthcare © 2012 The Joanna Briggs Institute.

Effects of deformation-induced martensite and grain size on ductile-to-brittle transition behavior of austenitic 18Cr-10Mn-N stainless steels

NASA Astrophysics Data System (ADS)

Hwang, Byoungchul; Lee, Tae-Ho; Kim, Sung-Joon

2010-12-01

Effects of deformation-induced martensite and grain size on ductile-to-brittle transition behavior of austenitic 18Cr-10Mn-(0.3˜0.6)N stainless steels with different alloying elements were investigated by means of Charpy impact tests and microstructural analyses. The steels all exhibited ductile-to-brittle transition behavior due to unusual brittle fracture at low temperatures despite having a face-centered cubic structure. The ductileto-brittle transition temperature (DBTT) obtained from Chapry impact tests did not coincide with that predicted by an empirical equation depending on N content in austenitic Cr-Mn-N stainless steels. Furthermore, a decrease of grain size was not effective in terms of lowering DBTT. Electron back-scattered diffraction and transmission electron microscopy analyses of the cross-sectional area of the fracture surface showed that some austenites with lower stability could be transformed to α'-martensite by localized plastic deformation near the fracture surface. Based on these results, it was suggested that when austenitic 18Cr-10Mn-N stainless steels have limited Ni, Mo, and N content, the deterioration of austenite stability promotes the formation of deformation-induced martensite and thus increases DBTT by substantially decreasing low-temperature toughness.

A General Framework for Power Analysis to Detect the Moderator Effects in Two- and Three-Level Cluster Randomized Trials

ERIC Educational Resources Information Center

Dong, Nianbo; Spybrook, Jessaca; Kelcey, Ben

2016-01-01

The purpose of this study is to propose a general framework for power analyses to detect the moderator effects in two- and three-level cluster randomized trials (CRTs). The study specifically aims to: (1) develop the statistical formulations for calculating statistical power, minimum detectable effect size (MDES) and its confidence interval to…

The effectiveness of air bags.

PubMed

Barry, S; Ginpil, S; O'Neill, T J

1999-11-01

Previous research has shown that the installation of air bags in vehicles significantly reduces crash related deaths, but these analyses have used statistical techniques which have not been capable of controlling for other major determinants of crash survival. This study analysed data from the US FARS database of fatal crashes using conditional logistic regression which is simultaneously able to estimate occupant protection effects for a range of variables. Results of the analysis provided a comparative quantification of both the effect of the air bag as well as other well known determinants of occupant crash survival (age, seat belt use, and gender). When potentially confounding variables were controlled, both the driver and passenger side air bag devices were shown to significantly reduce the probability of death in direct frontal collisions, but the effect size calculated was small compared to the effect of the seat belt. The effect size may also be very small in absolute terms depending on the severity of the crash involved. Given the limited benefit of the air bag, efforts to promote air bags seem particularly difficult to justify in countries such as the United States where the vastly superior occupant protection of the seat belt is under-utilised.

Is Ginkgo biloba a cognitive enhancer in healthy individuals? A meta-analysis.

PubMed

Laws, Keith R; Sweetnam, Hilary; Kondel, Tejinder K

2012-11-01

We conducted a meta-analysis to examine whether Ginkgo biloba (G. biloba) enhances cognitive function in healthy individuals. Scopus, Medline, Google Scholar databases and recent qualitative reviews were searched for studies examining the effects of G. biloba on cognitive function in healthy individuals. We identified randomised controlled trials containing data on memory (K = 13), executive function (K = 7) and attention (K = 8) from which effect sizes could be derived. The analyses provided measures of memory, executive function and attention in 1132, 534 and 910 participants, respectively. Effect sizes were non-significant and close to zero for memory (d = -0.04: 95%CI -0.17 to 0.07), executive function (d = -0.05: 95%CI -0.17 to 0.05) and attention (d = -0.08: 95%CI -0.21 to 0.02). Meta-regressions showed that effect sizes were not related to participant age, duration of the trial, daily dose, total dose or sample size. We report that G. biloba had no ascertainable positive effects on a range of targeted cognitive functions in healthy individuals. Copyright © 2012 John Wiley & Sons, Ltd.

Discrete hierarchy of sizes and performances in the exchange-traded fund universe

NASA Astrophysics Data System (ADS)

Vandermarliere, B.; Ryckebusch, J.; Schoors, K.; Cauwels, P.; Sornette, D.

2017-03-01

Using detailed statistical analyses of the size distribution of a universe of equity exchange-traded funds (ETFs), we discover a discrete hierarchy of sizes, which imprints a log-periodic structure on the probability distribution of ETF sizes that dominates the details of the asymptotic tail. This allows us to propose a classification of the studied universe of ETFs into seven size layers approximately organized according to a multiplicative ratio of 3.5 in their total market capitalization. Introducing a similarity metric generalizing the Herfindhal index, we find that the largest ETFs exhibit a significantly stronger intra-layer and inter-layer similarity compared with the smaller ETFs. Comparing the performance across the seven discerned ETF size layers, we find an inverse size effect, namely large ETFs perform significantly better than the small ones both in 2014 and 2015.

Fish movement and habitat use depends on water body size and shape

USGS Publications Warehouse

Woolnough, D.A.; Downing, J.A.; Newton, T.J.

2009-01-01

Home ranges are central to understanding habitat diversity, effects of fragmentation and conservation. The distance that an organism moves yields information on life history, genetics and interactions with other organisms. Present theory suggests that home range is set by body size of individuals. Here, we analyse estimates of home ranges in lakes and rivers to show that body size of fish and water body size and shape influence home range size. Using 71 studies including 66 fish species on five continents, we show that home range estimates increased with increasing water body size across water body shapes. This contrasts with past studies concluding that body size sets home range. We show that water body size was a consistently significant predictor of home range. In conjunction, body size and water body size can provide improved estimates of home range than just body size alone. As habitat patches are decreasing in size worldwide, our findings have implications for ecology, conservation and genetics of populations in fragmented ecosystems. ?? 2008 Blackwell Munksgaard.

Mass-specific scattering coefficient for natural minerogenic particle populations: particle size distribution effect and closure analyses.

PubMed

Peng, Feng; Effler, Steve W

2012-05-01

The relationship between the particulate scattering coefficient (b(p)) and the concentration of suspended particulate matter (SPM), as represented by the mass-specific scattering coefficient of particulates (b(p)*=b(p)/SPM), depends on particle size distribution (PSD). This dependence is quantified for minerogenic particle populations in this paper through calculations of b(p)* for common minerals as idealized populations (monodispersed spheres); contemporaneous measurements of b(p), SPM, and light-scattering attributes of mineral particles with scanning electron microscopy interfaced with automated image and x-ray analyses (SAX), for a connected stream-reservoir system where minerogenic particles dominate b(p); and estimates of b(p) and its size dependency (through SAX results-driven Mie theory calculations), particle volume concentration, and b(p)*. Modest changes in minerogenic PSDs are shown to result in substantial variations in b(p)*. Good closure of the SAX-based estimates of b(p) and particle volume concentration with bulk measurements is demonstrated. Converging relationships between b(p)* and particle size, developed from three approaches, were well described by power law expressions.

The Precision of Effect Size Estimation From Published Psychological Research: Surveying Confidence Intervals.

PubMed

Brand, Andrew; Bradley, Michael T

2016-02-01

Confidence interval ( CI) widths were calculated for reported Cohen's d standardized effect sizes and examined in two automated surveys of published psychological literature. The first survey reviewed 1,902 articles from Psychological Science. The second survey reviewed a total of 5,169 articles from across the following four APA journals: Journal of Abnormal Psychology, Journal of Applied Psychology, Journal of Experimental Psychology: Human Perception and Performance, and Developmental Psychology. The median CI width for d was greater than 1 in both surveys. Hence, CI widths were, as Cohen (1994) speculated, embarrassingly large. Additional exploratory analyses revealed that CI widths varied across psychological research areas and that CI widths were not discernably decreasing over time. The theoretical implications of these findings are discussed along with ways of reducing the CI widths and thus improving precision of effect size estimation.

An imbalance in cluster sizes does not lead to notable loss of power in cross-sectional, stepped-wedge cluster randomised trials with a continuous outcome.

PubMed

Kristunas, Caroline A; Smith, Karen L; Gray, Laura J

2017-03-07

The current methodology for sample size calculations for stepped-wedge cluster randomised trials (SW-CRTs) is based on the assumption of equal cluster sizes. However, as is often the case in cluster randomised trials (CRTs), the clusters in SW-CRTs are likely to vary in size, which in other designs of CRT leads to a reduction in power. The effect of an imbalance in cluster size on the power of SW-CRTs has not previously been reported, nor what an appropriate adjustment to the sample size calculation should be to allow for any imbalance. We aimed to assess the impact of an imbalance in cluster size on the power of a cross-sectional SW-CRT and recommend a method for calculating the sample size of a SW-CRT when there is an imbalance in cluster size. The effect of varying degrees of imbalance in cluster size on the power of SW-CRTs was investigated using simulations. The sample size was calculated using both the standard method and two proposed adjusted design effects (DEs), based on those suggested for CRTs with unequal cluster sizes. The data were analysed using generalised estimating equations with an exchangeable correlation matrix and robust standard errors. An imbalance in cluster size was not found to have a notable effect on the power of SW-CRTs. The two proposed adjusted DEs resulted in trials that were generally considerably over-powered. We recommend that the standard method of sample size calculation for SW-CRTs be used, provided that the assumptions of the method hold. However, it would be beneficial to investigate, through simulation, what effect the maximum likely amount of inequality in cluster sizes would be on the power of the trial and whether any inflation of the sample size would be required.

Dynamic size responses to climate change: prevailing effects of rising temperature drive long-term body size increases in a semi-arid passerine.

PubMed

Gardner, Janet L; Amano, Tatsuya; Mackey, Brendan G; Sutherland, William J; Clayton, Mark; Peters, Anne

2014-07-01

Changes in animal body size have been widely reported as a correlate of contemporary climate change. Body size affects metabolism and fitness, so changing size has implications for resilience, yet the climatic factors that drive size variation remain poorly understood. We test the role of mean and extreme temperature, rainfall, and remotely sensed primary productivity (NDVI) as drivers of body size in a sedentary, semi-arid Australian passerine, Ptilotula (Lichenostomus)penicillatus, over 23 years. To distinguish effects due to differential growth from changes in population composition, we analysed first-year birds and adults separately and considered climatic variation at three temporal scales (current, previous, and preceding 5 years). The strongest effects related to temperature: in both age classes, larger size was associated with warmer mean temperatures in the previous year, contrary to Bergmann's Rule. Moreover, adults were larger in warmer breeding seasons, while first years was larger after heat waves; these effects are more likely to be mediated through size-dependent mortality, highlighting the role of body size in determining vulnerability to extinction. In addition to temperature, larger adult size was associated with lower primary productivity, which may reflect a trade-off between vegetative growth and nectar production, on which adults rely. Finally, lower rainfall was associated with decreasing size in first year and adults, most likely related to decreased food availability. Overall,body size increased over 23 years, strongly in first-year birds (2.7%) compared with adults (1%), with size outcomes a balance between competing drivers. As rainfall declined over time and productivity remained fairly stable, the temporal increase in body size appears largely driven by rising mean temperature and temperature extremes. Body size responses to environmental change are thus complex and dynamic, driven by effects on growth as well as mortality.

Hydro-mechanically coupled finite-element analysis of the stability of a fractured-rock slope using the equivalent continuum approach: a case study of planned reservoir banks in Blaubeuren, Germany

NASA Astrophysics Data System (ADS)

Song, Jie; Dong, Mei; Koltuk, Serdar; Hu, Hui; Zhang, Luqing; Azzam, Rafig

2018-05-01

Construction works associated with the building of reservoirs in mountain areas can damage the stability of adjacent valley slopes. Seepage processes caused by the filling and drawdown operations of reservoirs also affect the stability of the reservoir banks over time. The presented study investigates the stability of a fractured-rock slope subjected to seepage forces in the lower basin of a planned pumped-storage hydropower (PSH) plant in Blaubeuren, Germany. The investigation uses a hydro-mechanically coupled finite-element analyses. For this purpose, an equivalent continuum model is developed by using a representative elementary volume (REV) approach. To determine the minimum required REV size, a large number of discrete fracture networks are generated using Monte Carlo simulations. These analyses give a REV size of 28 × 28 m, which is sufficient to represent the equivalent hydraulic and mechanical properties of the investigated fractured-rock mass. The hydro-mechanically coupled analyses performed using this REV size show that the reservoir operations in the examined PSH plant have negligible effect on the adjacent valley slope.

Particle Morphology Analysis of Biomass Material Based on Improved Image Processing Method

PubMed Central

Lu, Zhaolin

2017-01-01

Particle morphology, including size and shape, is an important factor that significantly influences the physical and chemical properties of biomass material. Based on image processing technology, a method was developed to process sample images, measure particle dimensions, and analyse the particle size and shape distributions of knife-milled wheat straw, which had been preclassified into five nominal size groups using mechanical sieving approach. Considering the great variation of particle size from micrometer to millimeter, the powders greater than 250 μm were photographed by a flatbed scanner without zoom function, and the others were photographed using a scanning electron microscopy (SEM) with high-image resolution. Actual imaging tests confirmed the excellent effect of backscattered electron (BSE) imaging mode of SEM. Particle aggregation is an important factor that affects the recognition accuracy of the image processing method. In sample preparation, the singulated arrangement and ultrasonic dispersion methods were used to separate powders into particles that were larger and smaller than the nominal size of 250 μm. In addition, an image segmentation algorithm based on particle geometrical information was proposed to recognise the finer clustered powders. Experimental results demonstrated that the improved image processing method was suitable to analyse the particle size and shape distributions of ground biomass materials and solve the size inconsistencies in sieving analysis. PMID:28298925

The effects of overwinter flowson the spring condition of rainbow and brown trout size classes in the Green River downstream of Flaming Gorge Dam, Utah.

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

Magnusson, A. K.; LaGory, K. E.; Hayse, J. W.

2010-06-25

Flaming Gorge Dam, a hydroelectric facility operated by the Bureau of Reclamation (Reclamation), is located on the Green River in Daggett County, northeastern Utah. Until recently, and since the early 1990s, single daily peak releases or steady flows have been the operational pattern of the dam during the winter period. However, releases from Flaming Gorge Reservoir followed a double-peak pattern (two daily flow peaks) during the winters of 2006-2007 and 2008-2009. Because there is little recent long-term history of double-peaking at Flaming Gorge Dam, the potential effects of double-peaking operations on trout body condition in the dam's tailwater are notmore » known. A study plan was developed that identified research activities to evaluate potential effects from winter double-peaking operations (Hayse et al. 2009). Along with other tasks, the study plan identified the need to conduct a statistical analysis of historical trout condition and macroinvertebrate abundance to evaluate the potential effects of hydropower operations. The results from analyses based on the combined size classes of trout (85-630 mm) were presented in Magnusson et al. (2008). The results of this earlier analysis suggested possible relationships between trout condition and flow, but concern that some of the relationships resulted from size-based effects (e.g., apparent changes in condition may have been related to concomitant changes in size distribution, because small trout may have responded differently to flow than large trout) prompted additional analysis of within-size class relationships. This report presents the results of analyses of three different size classes of trout (small: 200-299 mm, medium: 300-399 mm, and large: {ge}400 mm body length). We analyzed historical data to (1) describe temporal patterns and relationships among flows, benthic macroinvertebrate abundance, and condition of brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss) in the tailwaters of Flaming Gorge Dam, and to (2) evaluate the relative importance of the effects of flow (i.e., flow volumes and flow variability), trout abundance (catch per unit effort [CPUE]), and benthic macroinvertebrate abundance on trout condition for different size classes of trout.« less

Method and apparatus for analyzing particle-containing gaseous suspensions

DOEpatents

Solomon, Peter R.; Carangelo, Robert M.; Best, Philip E.

1987-01-01

The method and apparatus permit analyses, by optical means, of properties of gaseous suspensions of particles, by measuring radiation that is emitted, transmitted or scattered by the particles. Determinations of composition, size, temperature and spectral emittance can be performed either in-situ or by sampling, and Fourier-transform infrared spectrometric techniques are most effectively used. Apparatus specifically adapted for performing radiation scattering analyses, and for collecting radiation from different sources, are provided.

Method and apparatus for analyzing particle-containing gaseous suspensions

DOEpatents

Solomon, P.R.; Carangelo, R.M.; Best, P.E.

1987-03-24

The method and apparatus permit analyses, by optical means, of properties of gaseous suspensions of particles, by measuring radiation that is emitted, transmitted or scattered by the particles. Determinations of composition, size, temperature and spectral emittance can be performed either in-situ or by sampling, and Fourier-transform infrared spectrometric techniques are most effectively used. Apparatus specifically adapted for performing radiation scattering analyses, and for collecting radiation from different sources, are provided. 51 figs.

Non-cognate translation priming in masked priming lexical decision experiments: A meta-analysis.

PubMed

Wen, Yun; van Heuven, Walter J B

2017-06-01

The masked translation priming paradigm has been widely used in the last 25 years to investigate word processing in bilinguals. Motivated by studies reporting mixed findings, in particular for second language (L2) to first language (L1) translation priming, we conducted, for the first time in the literature, a meta-analysis of 64 masked priming lexical decision experiments across 24 studies to assess the effect sizes of L1-L2 and L2-L1 non-cognate translation priming effects in bilinguals. Our meta-analysis also investigated the influence of potential moderators of translation priming effects. The results provided clear evidence of significant translation priming effects for both directions, with L1-L2 translation priming significantly larger than L2-L1 translation priming (i.e., effect size of 0.86 vs. 0.31). The analyses also revealed that L1-L2 translation effect sizes were moderated by the interval between prime and target (ISI), whereas L2-L1 translation effect sizes were modulated by the number of items per cell. Theoretical and methodological implications of this meta-analysis are discussed and recommendations for future studies are provided.

Efficacy of cognitive-behavioral therapy for childhood anxiety and depression.

PubMed

Crowe, Katherine; McKay, Dean

2017-06-01

A review of meta-analyses of cognitive-behavioral therapy (CBT) for childhood anxiety and depression was conducted. A total of 36 meta-analyses were identified that met inclusion criteria for this review. In most cases, medium-to-large effect sizes for treatment reduction were observed when CBT was compared to non-active control conditions. Small-to-medium effects were observed when CBT was compared to active control treatments. The available meta-analyses generally did not examine, or data were not sufficient to evaluate, potential moderators of outcome, differential effects for parental involvement, or changes in quality of life or functional outcomes associated with treatment. Accordingly, while CBT should be broadly considered an effective treatment approach for childhood anxiety and depression, additional research is warranted in order to establish guidelines for service delivery for complicating factors in client presentation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Standardized mean differences cause funnel plot distortion in publication bias assessments.

PubMed

Zwetsloot, Peter-Paul; Van Der Naald, Mira; Sena, Emily S; Howells, David W; IntHout, Joanna; De Groot, Joris Ah; Chamuleau, Steven Aj; MacLeod, Malcolm R; Wever, Kimberley E

2017-09-08

Meta-analyses are increasingly used for synthesis of evidence from biomedical research, and often include an assessment of publication bias based on visual or analytical detection of asymmetry in funnel plots. We studied the influence of different normalisation approaches, sample size and intervention effects on funnel plot asymmetry, using empirical datasets and illustrative simulations. We found that funnel plots of the Standardized Mean Difference (SMD) plotted against the standard error (SE) are susceptible to distortion, leading to overestimation of the existence and extent of publication bias. Distortion was more severe when the primary studies had a small sample size and when an intervention effect was present. We show that using the Normalised Mean Difference measure as effect size (when possible), or plotting the SMD against a sample size-based precision estimate, are more reliable alternatives. We conclude that funnel plots using the SMD in combination with the SE are unsuitable for publication bias assessments and can lead to false-positive results.

Standardized mean differences cause funnel plot distortion in publication bias assessments

PubMed Central

Van Der Naald, Mira; Sena, Emily S; Howells, David W; IntHout, Joanna; De Groot, Joris AH; Chamuleau, Steven AJ; MacLeod, Malcolm R

2017-01-01

Meta-analyses are increasingly used for synthesis of evidence from biomedical research, and often include an assessment of publication bias based on visual or analytical detection of asymmetry in funnel plots. We studied the influence of different normalisation approaches, sample size and intervention effects on funnel plot asymmetry, using empirical datasets and illustrative simulations. We found that funnel plots of the Standardized Mean Difference (SMD) plotted against the standard error (SE) are susceptible to distortion, leading to overestimation of the existence and extent of publication bias. Distortion was more severe when the primary studies had a small sample size and when an intervention effect was present. We show that using the Normalised Mean Difference measure as effect size (when possible), or plotting the SMD against a sample size-based precision estimate, are more reliable alternatives. We conclude that funnel plots using the SMD in combination with the SE are unsuitable for publication bias assessments and can lead to false-positive results. PMID:28884685

Influence of particle size on physical and sensory attributes of mango pulp powder

NASA Astrophysics Data System (ADS)

Sharma, M.; Kadam, D. M.; Chadha, S.; Wilson, R. A.; Gupta, R. K.

2013-09-01

The present investigation was aimed to observe the effect of particle size on physical, sensory and thermal properties of foam-mat dried mango pulp powder. Mango pulp of Dussehri variety was foam-mat dried using 3% egg white at 65ºC. Dried foam-mats were pulverized and passed through a sieve shaker for obtaining three grades of powder with 50, 60, and 85 mesh size sieves. The particle size of these samples measured using laser diffraction particle size analyzer ranged from 191.26 to 296.19 μm. The data was analysed statistically using ANOVA of SAS. There was a linear increase in lightness (`L' value) with a decrease in particle size, however, `a' value decreased with a decrease in particle size, indicating the decrease in redness. An increase in bulk density and decrease in water solubility index and water absorption index % were observed with a decrease in particle size. Particle size had a significant effect on sensory parameters. Particle size in the range of 258.01 to 264.60μmwas found most acceptable with respect to sensory characteristics. This finding can be exploited for various commercial applicationswhere powder quality is dependent on the particle size and has foremost priority for end users.

Genomic data reveal a loss of diversity in two species of tuco-tucos (genus Ctenomys) following a volcanic eruption.

PubMed

Hsu, Jeremy L; Crawford, Jeremy Chase; Tammone, Mauro N; Ramakrishnan, Uma; Lacey, Eileen A; Hadly, Elizabeth A

2017-11-24

Marked reductions in population size can trigger corresponding declines in genetic variation. Understanding the precise genetic consequences of such reductions, however, is often challenging due to the absence of robust pre- and post-reduction datasets. Here, we use heterochronous genomic data from samples obtained before and immediately after the 2011 eruption of the Puyehue-Cordón Caulle volcanic complex in Patagonia to explore the genetic impacts of this event on two parapatric species of rodents, the colonial tuco-tuco (Ctenomys sociabilis) and the Patagonian tuco-tuco (C. haigi). Previous analyses using microsatellites revealed no post-eruption changes in genetic variation in C. haigi, but an unexpected increase in variation in C. sociabilis. To explore this outcome further, we used targeted gene capture to sequence over 2,000 putatively neutral regions for both species. Our data revealed that, contrary to the microsatellite analyses, the eruption was associated with a small but significant decrease in genetic variation in both species. We suggest that genome-level analyses provide greater power than traditional molecular markers to detect the genetic consequences of population size changes, particularly changes that are recent, short-term, or modest in size. Consequently, genomic analyses promise to generate important new insights into the effects of specific environmental events on demography and genetic variation.

Effects of chilled-then-frozen storage (up to 52weeks) on an indicator of protein oxidation and indices of protein degradation in lamb M. longissimus lumborum.

PubMed

Coombs, Cassius E O; Holman, Benjamin W B; Collins, Damian; Kerr, Matthew J; Friend, Michael A; Hopkins, David L

2018-01-01

This study investigated the protein oxidation properties of lamb following chilled-then-frozen storage. Experimental (n=360) M. longissimus lumborum (LL) were randomly sampled from the boning room of a commercial Australian abattoir, at 24h post mortem, and assigned to five chilled storage periods (0, 2, 4, 6 and 8weeks) and six subsequent frozen storage periods (0, 4, 8, 12, 24 and 52weeks). Upon completion of each storage treatment combination, corresponding LL were sub-sectioned and analysed for carbonyl content, protein solubility, nitrate/nitrite content, particle size analysis and estimated myoglobin fractions. The association between these protein measures and shear force was also explored. During chilled storage, particle size and sarcoplasmic protein solubility decreased which indicated protein degradation, while frozen storage only affected myoglobin oxidation. Tenderness was best explained by decreased particle size, decreased deoxymyoglobin and increased oxymyoglobin. No carbonyl effects were observed. It can be concluded that, according to these analyses, that in chilled-then-frozen lamb carbonyl formation was negligible. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Head circumference and brain size in autism spectrum disorder: A systematic review and meta-analysis.

PubMed

Sacco, Roberto; Gabriele, Stefano; Persico, Antonio M

2015-11-30

Macrocephaly and brain overgrowth have been associated with autism spectrum disorder. We performed a systematic review and meta-analysis to provide an overall estimate of effect size and statistical significance for both head circumference and total brain volume in autism. Our literature search strategy identified 261 and 391 records, respectively; 27 studies defining percentages of macrocephalic patients and 44 structural brain imaging studies providing total brain volumes for patients and controls were included in our meta-analyses. Head circumference was significantly larger in autistic compared to control individuals, with 822/5225 (15.7%) autistic individuals displaying macrocephaly. Structural brain imaging studies measuring brain volume estimated effect size. The effect size is higher in low functioning autistics compared to high functioning and ASD individuals. Brain overgrowth was recorded in 142/1558 (9.1%) autistic patients. Finally, we found a significant interaction between age and total brain volume, resulting in larger head circumference and brain size during early childhood. Our results provide conclusive effect sizes and prevalence rates for macrocephaly and brain overgrowth in autism, confirm the variation of abnormal brain growth with age, and support the inclusion of this endophenotype in multi-biomarker diagnostic panels for clinical use. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

[Particle Size Distribution and Pollutant Speciation Analyses of Stormwater Runoff in the Ancient Town of Suzhou].

PubMed

Li, Huai; Wu, Wei; Tian, Yong-jing; Huang, Tian-yin

2016-02-15

The particle size distribution (PSD) and its transformation processes in the stormwater runoffs in the ancient town of Suzhou were studied based on the particles size analyses, the water-quality monitoring data and the parameters of the rainfall-runoff models. The commercial districts, the modern residential area, the old residential area, the traffic area and the landscape tourist area were selected as the five functional example areas in the ancient town of Suzhou. The effects of antecedent dry period, the rainfall intensity and the amount of runoffs on the particle size distributions were studied, and the existing forms of the main pollutants in different functional areas and their possible relations were analyzed as well. The results showed that the particle size distribution, the migration processes and the output characteristics in the stormwater runoffs were greatly different in these five functional areas, which indicated different control measures for the pollution of the runoffs should be taken in the design process. The antecedent dry period, the rainfall intensity and the amount of runoffs showed significant correlations with the particle size distribution, showing these were the important factors. The output of the particles was greatly influenced by the flow scouring in the early period of the rainfall, and the correlations between the amount of runoffs and the particle migration ability presented significant difference in 30% (early period) and 70% (later period) of the runoff volume. The major existence form of the output pollutants was particle, and the correlation analyses of different diameter particles showed that the particles smaller than 150 microm were the dominant carrier of the pollutants via adsorption and accumulation processes.

Analyses of Diamond Wire Sawn Wafers: Effect of Various Cutting Parameters

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

Sopori, Bhushan; Basnyat, Prakash; Devayajanam, Srinivas

We have evaluated surface characteristics of diamond wire cut (DWC) wafers sawn under a variety of cutting parameters. These characteristics include surface roughness, spatial frequencies of surface profiles, phase changes, damage depth, and lateral non-uniformities in the surface damage. Various cutting parameters investigated are: wire size, diamond grit size, reciprocating frequency, feed rate, and wire usage. Spatial frequency components of surface topography/roughness are influenced by individual cutting parameters as manifested by distinct peaks in the Fourier transforms of the Dektak profiles. The depth of damage is strongly controlled by diamond grit size and wire usage and to a smaller degreemore » by the wire size.« less

The Examination of Teacher Burnout in Turkey: A Meta-Analysis

ERIC Educational Resources Information Center

Yorulmaz, Yilmaz Ilker; Altinkurt, Yahya

2018-01-01

The purpose of this study is to determine the effect of gender, marital status, subject matter, school type, educational status and seniority variables on teacher burnout. In this regard, a meta-analysis was conducted for the studies on teacher burnout in Turkey. The effect size analyses were performed with 100 studies for gender, 73 for marital…

Coherent Power Analysis in Multi-Level Studies Using Design Parameters from Surveys

ERIC Educational Resources Information Center

Rhoads, Christopher

2016-01-01

Current practice for conducting power analyses in hierarchical trials using survey based ICC and effect size estimates may be misestimating power because ICCs are not being adjusted to account for treatment effect heterogeneity. Results presented in Table 1 show that the necessary adjustments can be quite large or quite small. Furthermore, power…

Meta-Analysis that Conceals More than It Reveals: Comment on Storm Et Al. (2010)

ERIC Educational Resources Information Center

Hyman, Ray

2010-01-01

Storm, Tressoldi, and Di Risio (2010) rely on meta-analyses to justify their claim that the evidence for psi is consistent and reliable. They manufacture apparent homogeneity and consistency by eliminating many outliers and combining databases whose combined effect sizes are not significantly different--even though these combined effect sizes…

A Meta-Analytic Review of Obesity Prevention in the Schools: 1997-2008

ERIC Educational Resources Information Center

Cook-Cottone, Catherine; Casey, Carolyn M.; Feeley, Thomas Hugh; Baran, Jennifer

2009-01-01

A meta-analysis was conducted on school-based interventions to reduce obesity in children. Sixty-six (k = 66, N = 31,059) comparisons from 40 published studies from 1997 through 2008 were included in analyses. Results indicated a significant effect for school-based interventions with an overall weighted effect size of r = 0.05. Several moderating…

The evaluation of meta-analysis techniques for quantifying prescribed fire effects on fuel loadings.

Treesearch

Karen E. Kopper; Donald McKenzie; David L. Peterson

2009-01-01

Models and effect-size metrics for meta-analysis were compared in four separate meta-analyses quantifying surface fuels after prescribed fires in ponderosa pine (Pinus ponderosa Dougl. ex Laws.) forests of the Western United States. An aggregated data set was compiled from eight published reports that contained data from 65 fire treatment units....

Review and meta-analysis of genetic polymorphisms associated with exceptional human longevity.

PubMed

Revelas, Mary; Thalamuthu, Anbupalam; Oldmeadow, Christopher; Evans, Tiffany-Jane; Armstrong, Nicola J; Kwok, John B; Brodaty, Henry; Schofield, Peter R; Scott, Rodney J; Sachdev, Perminder S; Attia, John R; Mather, Karen A

2018-06-08

Many factors contribute to exceptional longevity, with genetics playing a significant role. However, to date, genetic studies examining exceptional longevity have been inconclusive. This comprehensive review seeks to determine the genetic variants associated with exceptional longevity by undertaking meta-analyses. Meta-analyses of genetic polymorphisms previously associated with exceptional longevity (85+) were undertaken. For each variant, meta-analyses were performed if there were data from at least three independent studies available, including two unpublished additional cohorts. Five polymorphisms, ACE rs4340, APOE ε2/3/4, FOXO3A rs2802292, KLOTHO KL-VS and IL6 rs1800795 were significantly associated with exceptional longevity, with the pooled effect sizes (odds ratios) ranging from 0.42 (APOE ε4) to 1.45 (FOXO3A males). In general, the observed modest effect sizes of the significant variants suggest many genes of small influence play a role in exceptional longevity, which is consistent with results for other polygenic traits. Our results also suggest that genes related to cardiovascular health may be implicated in exceptional longevity. Future studies should examine the roles of gender and ethnicity and carefully consider study design, including the selection of appropriate controls. Copyright © 2018. Published by Elsevier B.V.

Modulation of genetic associations with serum urate levels by body-mass-index in humans.

PubMed

Huffman, Jennifer E; Albrecht, Eva; Teumer, Alexander; Mangino, Massimo; Kapur, Karen; Johnson, Toby; Kutalik, Zoltán; Pirastu, Nicola; Pistis, Giorgio; Lopez, Lorna M; Haller, Toomas; Salo, Perttu; Goel, Anuj; Li, Man; Tanaka, Toshiko; Dehghan, Abbas; Ruggiero, Daniela; Malerba, Giovanni; Smith, Albert V; Nolte, Ilja M; Portas, Laura; Phipps-Green, Amanda; Boteva, Lora; Navarro, Pau; Johansson, Asa; Hicks, Andrew A; Polasek, Ozren; Esko, Tõnu; Peden, John F; Harris, Sarah E; Murgia, Federico; Wild, Sarah H; Tenesa, Albert; Tin, Adrienne; Mihailov, Evelin; Grotevendt, Anne; Gislason, Gauti K; Coresh, Josef; D'Adamo, Pio; Ulivi, Sheila; Vollenweider, Peter; Waeber, Gerard; Campbell, Susan; Kolcic, Ivana; Fisher, Krista; Viigimaa, Margus; Metter, Jeffrey E; Masciullo, Corrado; Trabetti, Elisabetta; Bombieri, Cristina; Sorice, Rossella; Döring, Angela; Reischl, Eva; Strauch, Konstantin; Hofman, Albert; Uitterlinden, Andre G; Waldenberger, Melanie; Wichmann, H-Erich; Davies, Gail; Gow, Alan J; Dalbeth, Nicola; Stamp, Lisa; Smit, Johannes H; Kirin, Mirna; Nagaraja, Ramaiah; Nauck, Matthias; Schurmann, Claudia; Budde, Kathrin; Farrington, Susan M; Theodoratou, Evropi; Jula, Antti; Salomaa, Veikko; Sala, Cinzia; Hengstenberg, Christian; Burnier, Michel; Mägi, Reedik; Klopp, Norman; Kloiber, Stefan; Schipf, Sabine; Ripatti, Samuli; Cabras, Stefano; Soranzo, Nicole; Homuth, Georg; Nutile, Teresa; Munroe, Patricia B; Hastie, Nicholas; Campbell, Harry; Rudan, Igor; Cabrera, Claudia; Haley, Chris; Franco, Oscar H; Merriman, Tony R; Gudnason, Vilmundur; Pirastu, Mario; Penninx, Brenda W; Snieder, Harold; Metspalu, Andres; Ciullo, Marina; Pramstaller, Peter P; van Duijn, Cornelia M; Ferrucci, Luigi; Gambaro, Giovanni; Deary, Ian J; Dunlop, Malcolm G; Wilson, James F; Gasparini, Paolo; Gyllensten, Ulf; Spector, Tim D; Wright, Alan F; Hayward, Caroline; Watkins, Hugh; Perola, Markus; Bochud, Murielle; Kao, W H Linda; Caulfield, Mark; Toniolo, Daniela; Völzke, Henry; Gieger, Christian; Köttgen, Anna; Vitart, Veronique

2015-01-01

We tested for interactions between body mass index (BMI) and common genetic variants affecting serum urate levels, genome-wide, in up to 42569 participants. Both stratified genome-wide association (GWAS) analyses, in lean, overweight and obese individuals, and regression-type analyses in a non BMI-stratified overall sample were performed. The former did not uncover any novel locus with a major main effect, but supported modulation of effects for some known and potentially new urate loci. The latter highlighted a SNP at RBFOX3 reaching genome-wide significant level (effect size 0.014, 95% CI 0.008-0.02, Pinter= 2.6 x 10-8). Two top loci in interaction term analyses, RBFOX3 and ERO1LB-EDARADD, also displayed suggestive differences in main effect size between the lean and obese strata. All top ranking loci for urate effect differences between BMI categories were novel and most had small magnitude but opposite direction effects between strata. They include the locus RBMS1-TANK (men, Pdifflean-overweight= 4.7 x 10-8), a region that has been associated with several obesity related traits, and TSPYL5 (men, Pdifflean-overweight= 9.1 x 10-8), regulating adipocytes-produced estradiol. The top-ranking known urate loci was ABCG2, the strongest known gout risk locus, with an effect halved in obese compared to lean men (Pdifflean-obese= 2 x 10-4). Finally, pathway analysis suggested a role for N-glycan biosynthesis as a prominent urate-associated pathway in the lean stratum. These results illustrate a potentially powerful way to monitor changes occurring in obesogenic environment.

Modulation of Genetic Associations with Serum Urate Levels by Body-Mass-Index in Humans

PubMed Central

Huffman, Jennifer E.; Albrecht, Eva; Teumer, Alexander; Mangino, Massimo; Kapur, Karen; Johnson, Toby; Kutalik, Zoltán; Pirastu, Nicola; Pistis, Giorgio; Lopez, Lorna M.; Haller, Toomas; Salo, Perttu; Goel, Anuj; Li, Man; Tanaka, Toshiko; Dehghan, Abbas; Ruggiero, Daniela; Malerba, Giovanni; Smith, Albert V.; Nolte, Ilja M.; Portas, Laura; Phipps-Green, Amanda; Boteva, Lora; Navarro, Pau; Johansson, Asa; Hicks, Andrew A.; Polasek, Ozren; Esko, Tõnu; Peden, John F.; Harris, Sarah E.; Murgia, Federico; Wild, Sarah H.; Tenesa, Albert; Tin, Adrienne; Mihailov, Evelin; Grotevendt, Anne; Gislason, Gauti K.; Coresh, Josef; D'Adamo, Pio; Ulivi, Sheila; Vollenweider, Peter; Waeber, Gerard; Campbell, Susan; Kolcic, Ivana; Fisher, Krista; Viigimaa, Margus; Metter, Jeffrey E.; Masciullo, Corrado; Trabetti, Elisabetta; Bombieri, Cristina; Sorice, Rossella; Döring, Angela; Reischl, Eva; Strauch, Konstantin; Hofman, Albert; Uitterlinden, Andre G.; Waldenberger, Melanie; Wichmann, H-Erich; Davies, Gail; Gow, Alan J.; Dalbeth, Nicola; Stamp, Lisa; Smit, Johannes H.; Kirin, Mirna; Nagaraja, Ramaiah; Nauck, Matthias; Schurmann, Claudia; Budde, Kathrin; Farrington, Susan M.; Theodoratou, Evropi; Jula, Antti; Salomaa, Veikko; Sala, Cinzia; Hengstenberg, Christian; Burnier, Michel; Mägi, Reedik; Klopp, Norman; Kloiber, Stefan; Schipf, Sabine; Ripatti, Samuli; Cabras, Stefano; Soranzo, Nicole; Homuth, Georg; Nutile, Teresa; Munroe, Patricia B.; Hastie, Nicholas; Campbell, Harry; Rudan, Igor; Cabrera, Claudia; Haley, Chris; Franco, Oscar H.; Merriman, Tony R.; Gudnason, Vilmundur; Pirastu, Mario; Penninx, Brenda W.; Snieder, Harold; Metspalu, Andres; Ciullo, Marina; Pramstaller, Peter P.; van Duijn, Cornelia M.; Ferrucci, Luigi; Gambaro, Giovanni; Deary, Ian J.; Dunlop, Malcolm G.; Wilson, James F.; Gasparini, Paolo; Gyllensten, Ulf; Spector, Tim D.; Wright, Alan F.; Hayward, Caroline; Watkins, Hugh; Perola, Markus; Bochud, Murielle; Kao, W. H. Linda; Caulfield, Mark; Toniolo, Daniela; Völzke, Henry; Gieger, Christian; Köttgen, Anna; Vitart, Veronique

2015-01-01

We tested for interactions between body mass index (BMI) and common genetic variants affecting serum urate levels, genome-wide, in up to 42569 participants. Both stratified genome-wide association (GWAS) analyses, in lean, overweight and obese individuals, and regression-type analyses in a non BMI-stratified overall sample were performed. The former did not uncover any novel locus with a major main effect, but supported modulation of effects for some known and potentially new urate loci. The latter highlighted a SNP at RBFOX3 reaching genome-wide significant level (effect size 0.014, 95% CI 0.008-0.02, Pinter= 2.6 x 10-8). Two top loci in interaction term analyses, RBFOX3 and ERO1LB-EDARADD, also displayed suggestive differences in main effect size between the lean and obese strata. All top ranking loci for urate effect differences between BMI categories were novel and most had small magnitude but opposite direction effects between strata. They include the locus RBMS1-TANK (men, Pdifflean-overweight= 4.7 x 10-8), a region that has been associated with several obesity related traits, and TSPYL5 (men, Pdifflean-overweight= 9.1 x 10-8), regulating adipocytes-produced estradiol. The top-ranking known urate loci was ABCG2, the strongest known gout risk locus, with an effect halved in obese compared to lean men (Pdifflean-obese= 2 x 10-4). Finally, pathway analysis suggested a role for N-glycan biosynthesis as a prominent urate-associated pathway in the lean stratum. These results illustrate a potentially powerful way to monitor changes occurring in obesogenic environment. PMID:25811787

Upward counterfactual thinking and depression: A meta-analysis.

PubMed

Broomhall, Anne Gene; Phillips, Wendy J; Hine, Donald W; Loi, Natasha M

2017-07-01

This meta-analysis examined the strength of association between upward counterfactual thinking and depressive symptoms. Forty-two effect sizes from a pooled sample of 13,168 respondents produced a weighted average effect size of r=.26, p<.001. Moderator analyses using an expanded set of 96 effect sizes indicated that upward counterfactuals and regret produced significant positive effects that were similar in strength. Effects also did not vary as a function of the theme of the counterfactual-inducing situation or study design (cross-sectional versus longitudinal). Significant effect size heterogeneity was observed across sample types, methods of assessing upward counterfactual thinking, and types of depression scale. Significant positive effects were found in studies that employed samples of bereaved individuals, older adults, terminally ill patients, or university students, but not adolescent mothers or mixed samples. Both number-based and Likert-based upward counterfactual thinking assessments produced significant positive effects, with the latter generating a larger effect. All depression scales produced significant positive effects, except for the Psychiatric Epidemiology Research Interview. Research and theoretical implications are discussed in relation to cognitive theories of depression and the functional theory of upward counterfactual thinking, and important gaps in the extant research literature are identified. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Effectiveness of Teamwork Training on Teamwork Behaviors and Team Performance: A Systematic Review and Meta-Analysis of Controlled Interventions

PubMed Central

McEwan, Desmond; Ruissen, Geralyn R.; Eys, Mark A.; Zumbo, Bruno D.; Beauchamp, Mark R.

2017-01-01

The objective of this study was to conduct a systematic review and meta-analysis of teamwork interventions that were carried out with the purpose of improving teamwork and team performance, using controlled experimental designs. A literature search returned 16,849 unique articles. The meta-analysis was ultimately conducted on 51 articles, comprising 72 (k) unique interventions, 194 effect sizes, and 8439 participants, using a random effects model. Positive and significant medium-sized effects were found for teamwork interventions on both teamwork and team performance. Moderator analyses were also conducted, which generally revealed positive and significant effects with respect to several sample, intervention, and measurement characteristics. Implications for effective teamwork interventions as well as considerations for future research are discussed. PMID:28085922

Survival analysis and classification methods for forest fire size

PubMed Central

2018-01-01

Factors affecting wildland-fire size distribution include weather, fuels, and fire suppression activities. We present a novel application of survival analysis to quantify the effects of these factors on a sample of sizes of lightning-caused fires from Alberta, Canada. Two events were observed for each fire: the size at initial assessment (by the first fire fighters to arrive at the scene) and the size at “being held” (a state when no further increase in size is expected). We developed a statistical classifier to try to predict cases where there will be a growth in fire size (i.e., the size at “being held” exceeds the size at initial assessment). Logistic regression was preferred over two alternative classifiers, with covariates consistent with similar past analyses. We conducted survival analysis on the group of fires exhibiting a size increase. A screening process selected three covariates: an index of fire weather at the day the fire started, the fuel type burning at initial assessment, and a factor for the type and capabilities of the method of initial attack. The Cox proportional hazards model performed better than three accelerated failure time alternatives. Both fire weather and fuel type were highly significant, with effects consistent with known fire behaviour. The effects of initial attack method were not statistically significant, but did suggest a reverse causality that could arise if fire management agencies were to dispatch resources based on a-priori assessment of fire growth potentials. We discuss how a more sophisticated analysis of larger data sets could produce unbiased estimates of fire suppression effect under such circumstances. PMID:29320497

Survival analysis and classification methods for forest fire size.

PubMed

Tremblay, Pier-Olivier; Duchesne, Thierry; Cumming, Steven G

2018-01-01

Factors affecting wildland-fire size distribution include weather, fuels, and fire suppression activities. We present a novel application of survival analysis to quantify the effects of these factors on a sample of sizes of lightning-caused fires from Alberta, Canada. Two events were observed for each fire: the size at initial assessment (by the first fire fighters to arrive at the scene) and the size at "being held" (a state when no further increase in size is expected). We developed a statistical classifier to try to predict cases where there will be a growth in fire size (i.e., the size at "being held" exceeds the size at initial assessment). Logistic regression was preferred over two alternative classifiers, with covariates consistent with similar past analyses. We conducted survival analysis on the group of fires exhibiting a size increase. A screening process selected three covariates: an index of fire weather at the day the fire started, the fuel type burning at initial assessment, and a factor for the type and capabilities of the method of initial attack. The Cox proportional hazards model performed better than three accelerated failure time alternatives. Both fire weather and fuel type were highly significant, with effects consistent with known fire behaviour. The effects of initial attack method were not statistically significant, but did suggest a reverse causality that could arise if fire management agencies were to dispatch resources based on a-priori assessment of fire growth potentials. We discuss how a more sophisticated analysis of larger data sets could produce unbiased estimates of fire suppression effect under such circumstances.

The Lilliput Effect in Colonial Organisms: Cheilostome Bryozoans at the Cretaceous–Paleogene Mass Extinction

PubMed Central

Sogot, Caroline E.; Harper, Elizabeth M.; Taylor, Paul D.

2014-01-01

Consistent trends towards decreasing body size in the aftermath of mass extinctions – Lilliput effects – imply a predictable response among unitary animals to these events. The occurrence of Lilliput effects has yet to be widely tested in colonial organisms, which are of particular interest as size change may potentially occur at the two hierarchical levels of the colony and the individual zooids. Bryozoans are particularly useful organisms in which to study colonial size response as they have well-defined zooids. Additionally, a number of analyses of present-day bryozoans have shown that zooid size reflects local environmental conditions, most notably seawater temperature and possibly also food supply. Following the hypothesised decline in primary productivity at the Cretaceous–Paleogene (K–Pg) mass extinction, it is predicted that bryozoan zooid size should decline in the early Paleogene, resulting in a Lilliput effect. To test this prediction, zooid size was compared across the K–Pg boundary at the assemblage level and also within 4 surviving genera. Analysis of 59 bryozoan species from assemblages on either side of the K–Pg boundary showed no significant change in zooid length. Zooid size was also measured in 98 Maastrichtian colonies and 162 Danian colonies belonging to four congeneric species. Only one of these genera showed a significant size decrease across the K–Pg boundary, the other three maintaining constant zooidal lengths, widths and areas. Additionally, the sizes of 210 Maastrichtian colonies and 163 Danian colonies did not show consistent size decrease across the K–Pg boundary in these same species, although maximum colony size did decline in three out of four genera. Furthermore, this lack of consistent size change is uniform between two distinct biogeographical regions, Denmark and the southeastern USA. PMID:24505275

Measuring Effectiveness in a Virtual Library

ERIC Educational Resources Information Center

Finch, Jannette L.

2010-01-01

Measuring quality of service in academic libraries traditionally includes quantifiable data such as collection size, staff counts, circulation numbers, reference service statistics, qualitative analyses of customer satisfaction, shelving accuracy, and building comfort. In the libraries of the third millennium, virtual worlds, Web content and…

A modified Wright-Fisher model that incorporates Ne: A variant of the standard model with increased biological realism and reduced computational complexity.

PubMed

Zhao, Lei; Gossmann, Toni I; Waxman, David

2016-03-21

The Wright-Fisher model is an important model in evolutionary biology and population genetics. It has been applied in numerous analyses of finite populations with discrete generations. It is recognised that real populations can behave, in some key aspects, as though their size that is not the census size, N, but rather a smaller size, namely the effective population size, Ne. However, in the Wright-Fisher model, there is no distinction between the effective and census population sizes. Equivalently, we can say that in this model, Ne coincides with N. The Wright-Fisher model therefore lacks an important aspect of biological realism. Here, we present a method that allows Ne to be directly incorporated into the Wright-Fisher model. The modified model involves matrices whose size is determined by Ne. Thus apart from increased biological realism, the modified model also has reduced computational complexity, particularly so when Ne⪡N. For complex problems, it may be hard or impossible to numerically analyse the most commonly-used approximation of the Wright-Fisher model that incorporates Ne, namely the diffusion approximation. An alternative approach is simulation. However, the simulations need to be sufficiently detailed that they yield an effective size that is different to the census size. Simulations may also be time consuming and have attendant statistical errors. The method presented in this work may then be the only alternative to simulations, when Ne differs from N. We illustrate the straightforward application of the method to some problems involving allele fixation and the determination of the equilibrium site frequency spectrum. We then apply the method to the problem of fixation when three alleles are segregating in a population. This latter problem is significantly more complex than a two allele problem and since the diffusion equation cannot be numerically solved, the only other way Ne can be incorporated into the analysis is by simulation. We have achieved good accuracy in all cases considered. In summary, the present work extends the realism and tractability of an important model of evolutionary biology and population genetics. Copyright © 2016 Elsevier Ltd. All rights reserved.

No category specificity in Alzheimer's disease: a normal aging effect.

PubMed

Moreno-Martínez, F Javier; Laws, Keith R

2008-07-01

The authors examined category effects on tasks of picture naming, naming to definition, and word-picture matching in 38 patients with Alzheimer's disease (AD) and 30 elderly controls. Each task was matched across category on all "nuisance" variables known to differ across domains. Standard analyses revealed significant category disadvantages for classifying living things in AD patients but also for elderly controls on each task. To overcome the ceiling effect in controls, the authors conducted 1,000 bootstrap analyses of covariance, with control performance as a difficulty index covariate. These covariate analyses eliminated the category effect in AD patients on all 3 tasks. Indeed, the authors report that control performance accounted for 64% (picture naming), 49% (naming to description), and 42% (word-picture matching) of variance in AD performance. This suggests that, although category effects in AD patients do not reflect intrinsic variables, the size and direction of the category effect are not different from those in elderly controls. PsycINFO Database Record (c) 2008 APA, all rights reserved.

The ACTIV study: acupuncture treatment in provoked vestibulodynia.

PubMed

Curran, Stephanie; Brotto, Lori A; Fisher, Harris; Knudson, Gail; Cohen, Trevor

2010-02-01

Provoked vestibulodynia (PVD) is a distressing genital pain condition affecting 12% of women. Treatment modalities vary and although vestibulectomy has the highest efficacy rates, it is usually not a first-line option. Acupuncture has a long history in the traditional Chinese medicine (TCM) system and operates on the premise that pain results from the blockage or imbalance of important channels. The main principle of treatment is to move Qi and blood to cease genital pain. To explore effect sizes and feasibility in a pilot study of acupuncture for women with PVD. Eight women with PVD (mean age 30 years) underwent 10 1-hour acupuncture sessions. Specific placement of the needles depended on the woman's individual TCM diagnosis. TCM practitioners made qualitative notes on participants' feedback after each session. Main Outcome Measures. Self-reported pain (investigator-developed), pain-associated cognitions (Pain Catastrophizing Scale [PCS], Pain Vigilance and Awareness Questionnaire), and sexual response (Female Sexual Function Index) were measured before and after treatment sessions 5 and 10. Qualitative analyses of TCM practitioner notes were performed along with one in-depth case report on the experience of a participant. A repeated measures analysis of variance revealed significant decreases in pain with manual genital stimulation and helplessness on the PCS. An examination of effect sizes also revealed strong (though nonsignificant) effects for improved ability to have intercourse and sexual desire. Qualitative analyses were overall more positive and revealed an improvement in perceived sexual health, reduced pain, and improved mental well-being in the majority of participants. Effect sizes and qualitative analyses of practitioner-initiated interviews showed overall positive effects of acupuncture, but there were statistically significant improvements only in pain with manual genital stimulation and helplessness. These findings require replication in a larger, controlled trial before any definitive conclusions on the efficacy of acupuncture for PVD can be made.

An assessment of the effects of cell size on AGNPS modeling of watershed runoff

USGS Publications Warehouse

Wu, S.-S.; Usery, E.L.; Finn, M.P.; Bosch, D.D.

2008-01-01

This study investigates the changes in simulated watershed runoff from the Agricultural NonPoint Source (AGNPS) pollution model as a function of model input cell size resolution for eight different cell sizes (30 m, 60 m, 120 m, 210 m, 240 m, 480 m, 960 m, and 1920 m) for the Little River Watershed (Georgia, USA). Overland cell runoff (area-weighted cell runoff), total runoff volume, clustering statistics, and hot spot patterns were examined for the different cell sizes and trends identified. Total runoff volumes decreased with increasing cell size. Using data sets of 210-m cell size or smaller in conjunction with a representative watershed boundary allows one to model the runoff volumes within 0.2 percent accuracy. The runoff clustering statistics decrease with increasing cell size; a cell size of 960 m or smaller is necessary to indicate significant high-runoff clustering. Runoff hot spot areas have a decreasing trend with increasing cell size; a cell size of 240 m or smaller is required to detect important hot spots. Conclusions regarding cell size effects on runoff estimation cannot be applied to local watershed areas due to the inconsistent changes of runoff volume with cell size; but, optimal cells sizes for clustering and hot spot analyses are applicable to local watershed areas due to the consistent trends.

High correlations between MRI brain volume measurements based on NeuroQuant® and FreeSurfer.

PubMed

Ross, David E; Ochs, Alfred L; Tate, David F; Tokac, Umit; Seabaugh, John; Abildskov, Tracy J; Bigler, Erin D

2018-05-30

NeuroQuant ® (NQ) and FreeSurfer (FS) are commonly used computer-automated programs for measuring MRI brain volume. Previously they were reported to have high intermethod reliabilities but often large intermethod effect size differences. We hypothesized that linear transformations could be used to reduce the large effect sizes. This study was an extension of our previously reported study. We performed NQ and FS brain volume measurements on 60 subjects (including normal controls, patients with traumatic brain injury, and patients with Alzheimer's disease). We used two statistical approaches in parallel to develop methods for transforming FS volumes into NQ volumes: traditional linear regression, and Bayesian linear regression. For both methods, we used regression analyses to develop linear transformations of the FS volumes to make them more similar to the NQ volumes. The FS-to-NQ transformations based on traditional linear regression resulted in effect sizes which were small to moderate. The transformations based on Bayesian linear regression resulted in all effect sizes being trivially small. To our knowledge, this is the first report describing a method for transforming FS to NQ data so as to achieve high reliability and low effect size differences. Machine learning methods like Bayesian regression may be more useful than traditional methods. Copyright © 2018 Elsevier B.V. All rights reserved.

Subcortical brain volume differences of participants with ADHD across the lifespan: an ENIGMA collaboration

PubMed Central

Hoogman, Martine; Bralten, Janita; Hibar, Derrek P.; Mennes, Maarten; Zwiers, Marcel P.; Schweren, Lizanne; van Hulzen, Kimm J.E.; Medland, Sarah E.; Shumskaya, Elena; Jahanshad, Neda; de Zeeuw, Patrick; Szekely, Eszter; Sudre, Gustavo; Wolfers, Thomas; Onnink, Alberdingk M.H.; Dammers, Janneke T.; Mostert, Jeanette C.; Vives-Gilabert, Yolanda; Kohls, Gregor; Oberwelland, Eileen; Seitz, Jochen; Schulte-Rüther, Martin; di Bruttopilo, Sara Ambrosino; Doyle, Alysa E.; Høvik, Marie F.; Dramsdahl, Margaretha; Tamm, Leanne; van Erp, Theo G.M.; Dale, Anders; Schork, Andrew; Conzelmann, Annette; Zierhut, Kathrin; Baur, Ramona; McCarthy, Hazel; Yoncheva, Yuliya N.; Cubillo, Ana; Chantiluke, Kaylita; Mehta, Mitul A.; Paloyelis, Yannis; Hohmann, Sarah; Baumeister, Sarah; Bramati, Ivanei; Mattos, Paulo; Tovar-Moll, Fernanda; Douglas, Pamela; Banaschewski, Tobias; Brandeis, Daniel; Kuntsi, Jonna; Asherson, Phil; Rubia, Katya; Kelly, Clare; Di Martino, Adriana; Milham, Michael P.; Castellanos, Francisco X.; Frodl, Thomas; Zentis, Mariam; Lesch, Klaus-Peter; Reif, Andreas; Pauli, Paul; Jernigan, Terry; Haavik, Jan; Plessen, Kerstin J.; Lundervold, Astri J.; Hugdahl, Kenneth; Seidman, Larry J.; Biederman, Joseph; Rommelse, Nanda; Heslenfeld, Dirk J.; Hartman, Catharina; Hoekstra, Pieter J.; Oosterlaan, Jaap; von Polier, Georg; Konrad, Kerstin; Vilarroya, Oscar; Ramos-Quiroga, Josep-Antoni; Soliva, Joan Carles; Durston, Sarah; Buitelaar, Jan K.; Faraone, Stephen V.; Shaw, Philip; Thompson, Paul; Franke, Barbara

2017-01-01

BACKGROUND Neuroimaging studies show structural alterations in several brain regions in children and adults with attention-deficit/hyperactivity disorder (ADHD). Through the formation of the worldwide ENIGMA ADHD Working Group, we addressed weaknesses of prior imaging studies and meta-analyses in sample size and methodological heterogeneity. METHODS Our sample comprised 1713 participants with ADHD and 1529 controls from 23 sites (age range: 4–63 years; 66% males). Individual sites analyzed magnetic resonance imaging brain scans with harmonized protocols. Case-control differences in subcortical structures and intracranial volume (ICV) were assessed through mega-and meta-analysis. FINDINGS The volumes of the accumbens (Cohen’s d=−0.15), amygdala (d=−0.19), caudate (d=−0.11), hippocampus (d=−0.11), putamen (d=−0.14), and ICV (d=−0.10) were found to be smaller in cases relative to controls. Effect sizes were highest in children, case-control differences were not present in adults. Explorative lifespan modeling suggested a delay of maturation and a delay of degeneration. Psychostimulant medication use or presence of comorbid psychiatric disorders did not influence results, nor did symptom scores correlate with brain volume. INTERPRETATION Using the largest data set to date, we extend the brain maturation delay theory for ADHD to include subcortical structures and refute medication effects on brain volume suggested by earlier meta-analyses. We add new knowledge about bilateral amygdala, accumbens, and hippocampus reductions in ADHD, and provide unprecedented precision in effect size estimates. Lifespan analyses suggest that, in the absence of well-powered longitudinal studies, the ENIGMA cross-sectional sample across six decades of life provides a means to generate hypotheses about lifespan trajectories in brain phenotypes. FUNDING National Institutes of Health PMID:28219628

Estimating the Effective Sample Size of Tree Topologies from Bayesian Phylogenetic Analyses

PubMed Central

Lanfear, Robert; Hua, Xia; Warren, Dan L.

2016-01-01

Bayesian phylogenetic analyses estimate posterior distributions of phylogenetic tree topologies and other parameters using Markov chain Monte Carlo (MCMC) methods. Before making inferences from these distributions, it is important to assess their adequacy. To this end, the effective sample size (ESS) estimates how many truly independent samples of a given parameter the output of the MCMC represents. The ESS of a parameter is frequently much lower than the number of samples taken from the MCMC because sequential samples from the chain can be non-independent due to autocorrelation. Typically, phylogeneticists use a rule of thumb that the ESS of all parameters should be greater than 200. However, we have no method to calculate an ESS of tree topology samples, despite the fact that the tree topology is often the parameter of primary interest and is almost always central to the estimation of other parameters. That is, we lack a method to determine whether we have adequately sampled one of the most important parameters in our analyses. In this study, we address this problem by developing methods to estimate the ESS for tree topologies. We combine these methods with two new diagnostic plots for assessing posterior samples of tree topologies, and compare their performance on simulated and empirical data sets. Combined, the methods we present provide new ways to assess the mixing and convergence of phylogenetic tree topologies in Bayesian MCMC analyses. PMID:27435794

Modelled Cost-Effectiveness of a Package Size Cap and a Kilojoule Reduction Intervention to Reduce Energy Intake from Sugar-Sweetened Beverages in Australia.

PubMed

Crino, Michelle; Herrera, Ana Maria Mantilla; Ananthapavan, Jaithri; Wu, Jason H Y; Neal, Bruce; Lee, Yong Yi; Zheng, Miaobing; Lal, Anita; Sacks, Gary

2017-09-06

Interventions targeting portion size and energy density of food and beverage products have been identified as a promising approach for obesity prevention. This study modelled the potential cost-effectiveness of: a package size cap on single-serve sugar sweetened beverages (SSBs) >375 mL ( package size cap ), and product reformulation to reduce energy content of packaged SSBs ( energy reduction ). The cost-effectiveness of each intervention was modelled for the 2010 Australia population using a multi-state life table Markov model with a lifetime time horizon. Long-term health outcomes were modelled from calculated changes in body mass index to their impact on Health-Adjusted Life Years (HALYs). Intervention costs were estimated from a limited societal perspective. Cost and health outcomes were discounted at 3%. Total intervention costs estimated in AUD 2010 were AUD 210 million. Both interventions resulted in reduced mean body weight ( package size cap : 0.12 kg; energy reduction : 0.23 kg); and HALYs gained ( package size cap : 73,883; energy reduction : 144,621). Cost offsets were estimated at AUD 750.8 million ( package size cap ) and AUD 1.4 billion ( energy reduction ). Cost-effectiveness analyses showed that both interventions were "dominant", and likely to result in long term cost savings and health benefits. A package size cap and kJ reduction of SSBs are likely to offer excellent "value for money" as obesity prevention measures in Australia.

Modelled Cost-Effectiveness of a Package Size Cap and a Kilojoule Reduction Intervention to Reduce Energy Intake from Sugar-Sweetened Beverages in Australia

PubMed Central

Mantilla Herrera, Ana Maria; Neal, Bruce; Zheng, Miaobing; Lal, Anita; Sacks, Gary

2017-01-01

Interventions targeting portion size and energy density of food and beverage products have been identified as a promising approach for obesity prevention. This study modelled the potential cost-effectiveness of: a package size cap on single-serve sugar sweetened beverages (SSBs) >375 mL (package size cap), and product reformulation to reduce energy content of packaged SSBs (energy reduction). The cost-effectiveness of each intervention was modelled for the 2010 Australia population using a multi-state life table Markov model with a lifetime time horizon. Long-term health outcomes were modelled from calculated changes in body mass index to their impact on Health-Adjusted Life Years (HALYs). Intervention costs were estimated from a limited societal perspective. Cost and health outcomes were discounted at 3%. Total intervention costs estimated in AUD 2010 were AUD 210 million. Both interventions resulted in reduced mean body weight (package size cap: 0.12 kg; energy reduction: 0.23 kg); and HALYs gained (package size cap: 73,883; energy reduction: 144,621). Cost offsets were estimated at AUD 750.8 million (package size cap) and AUD 1.4 billion (energy reduction). Cost-effectiveness analyses showed that both interventions were “dominant”, and likely to result in long term cost savings and health benefits. A package size cap and kJ reduction of SSBs are likely to offer excellent “value for money” as obesity prevention measures in Australia. PMID:28878175

Developmental plasticity in reptiles: Insights into thermal and maternal effects on chameleon phenotypes.

PubMed

Andrews, Robin M

2018-04-23

Embryonic environments affect a range of phenotypic traits including sex and reproductive success. I determined (1) how the interaction between incubation temperature and egg size affects sex allocation of Chamaeleo calyptratus and (2) how incubation temperature and maternal parent (clutch) affect water uptake by eggs and body size, growth, and climbing speed of hatchlings and juveniles. Eggs from five clutches were exposed to five temperature treatments with clutches replicated within and among treatments. Temperature affected sex, but only when egg size was included as a factor in analyses. At intermediate (28°C) temperatures, daughters were more likely to be produced from large eggs and sons more likely to be produced from small eggs, while at 25 and 30°C, the pattern of sex allocation was reversed. Temperature and clutch affected water uptake and body size. Nonetheless, the direction of temperature and clutch effects on water uptake by eggs and on the size of hatchlings were not the same and the direction of temperature effects on body sizes of hatchlings and juveniles differed as well. Clutch affected hatchling size but not juvenile size and growth rate. Clutch, but not incubation temperature, affected climbing speed, but the fastest hatchlings were not from the same clutches as the fastest juveniles. The independent effects of incubation temperature and clutch indicate that hatchling phenotypes are influenced largely by conditions experienced during incubation, while juvenile phenotypes are influenced largely by conditions experienced in the rearing environment. © 2018 Wiley Periodicals, Inc.

A Multilab Preregistered Replication of the Ego-Depletion Effect.

PubMed

Hagger, Martin S; Chatzisarantis, Nikos L D; Alberts, Hugo; Anggono, Calvin Octavianus; Batailler, Cédric; Birt, Angela R; Brand, Ralf; Brandt, Mark J; Brewer, Gene; Bruyneel, Sabrina; Calvillo, Dustin P; Campbell, W Keith; Cannon, Peter R; Carlucci, Marianna; Carruth, Nicholas P; Cheung, Tracy; Crowell, Adrienne; De Ridder, Denise T D; Dewitte, Siegfried; Elson, Malte; Evans, Jacqueline R; Fay, Benjamin A; Fennis, Bob M; Finley, Anna; Francis, Zoë; Heise, Elke; Hoemann, Henrik; Inzlicht, Michael; Koole, Sander L; Koppel, Lina; Kroese, Floor; Lange, Florian; Lau, Kevin; Lynch, Bridget P; Martijn, Carolien; Merckelbach, Harald; Mills, Nicole V; Michirev, Alexej; Miyake, Akira; Mosser, Alexandra E; Muise, Megan; Muller, Dominique; Muzi, Milena; Nalis, Dario; Nurwanti, Ratri; Otgaar, Henry; Philipp, Michael C; Primoceri, Pierpaolo; Rentzsch, Katrin; Ringos, Lara; Schlinkert, Caroline; Schmeichel, Brandon J; Schoch, Sarah F; Schrama, Michel; Schütz, Astrid; Stamos, Angelos; Tinghög, Gustav; Ullrich, Johannes; vanDellen, Michelle; Wimbarti, Supra; Wolff, Wanja; Yusainy, Cleoputri; Zerhouni, Oulmann; Zwienenberg, Maria

2016-07-01

Good self-control has been linked to adaptive outcomes such as better health, cohesive personal relationships, success in the workplace and at school, and less susceptibility to crime and addictions. In contrast, self-control failure is linked to maladaptive outcomes. Understanding the mechanisms by which self-control predicts behavior may assist in promoting better regulation and outcomes. A popular approach to understanding self-control is the strength or resource depletion model. Self-control is conceptualized as a limited resource that becomes depleted after a period of exertion resulting in self-control failure. The model has typically been tested using a sequential-task experimental paradigm, in which people completing an initial self-control task have reduced self-control capacity and poorer performance on a subsequent task, a state known as ego depletion Although a meta-analysis of ego-depletion experiments found a medium-sized effect, subsequent meta-analyses have questioned the size and existence of the effect and identified instances of possible bias. The analyses served as a catalyst for the current Registered Replication Report of the ego-depletion effect. Multiple laboratories (k = 23, total N = 2,141) conducted replications of a standardized ego-depletion protocol based on a sequential-task paradigm by Sripada et al. Meta-analysis of the studies revealed that the size of the ego-depletion effect was small with 95% confidence intervals (CIs) that encompassed zero (d = 0.04, 95% CI [-0.07, 0.15]. We discuss implications of the findings for the ego-depletion effect and the resource depletion model of self-control. © The Author(s) 2016.

The Small Nuclear Genomes of Selaginella Are Associated with a Low Rate of Genome Size Evolution.

PubMed

Baniaga, Anthony E; Arrigo, Nils; Barker, Michael S

2016-06-03

The haploid nuclear genome size (1C DNA) of vascular land plants varies over several orders of magnitude. Much of this observed diversity in genome size is due to the proliferation and deletion of transposable elements. To date, all vascular land plant lineages with extremely small nuclear genomes represent recently derived states, having ancestors with much larger genome sizes. The Selaginellaceae represent an ancient lineage with extremely small genomes. It is unclear how small nuclear genomes evolved in Selaginella We compared the rates of nuclear genome size evolution in Selaginella and major vascular plant clades in a comparative phylogenetic framework. For the analyses, we collected 29 new flow cytometry estimates of haploid genome size in Selaginella to augment publicly available data. Selaginella possess some of the smallest known haploid nuclear genome sizes, as well as the lowest rate of genome size evolution observed across all vascular land plants included in our analyses. Additionally, our analyses provide strong support for a history of haploid nuclear genome size stasis in Selaginella Our results indicate that Selaginella, similar to other early diverging lineages of vascular land plants, has relatively low rates of genome size evolution. Further, our analyses highlight that a rapid transition to a small genome size is only one route to an extremely small genome. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Population dynamics of American horseshoe crabs-historic climatic events and recent anthropogenic pressures

USGS Publications Warehouse

Faurby, S.; King, T.L.; Obst, M.; Hallerman, E.M.; Pertoldi, C.; Funch, P.

2010-01-01

Populations of the American horseshoe crab, Limulus polyphemus, have declined, but neither the causes nor the magnitude are fully understood. In order to evaluate historic demography, variation at 12 microsatellite DNA loci surveyed in 1218 L. polyphemus sampled from 28 localities was analysed with Bayesian coalescent-based methods. The analysis showed strong declines in population sizes throughout the species' distribution except in the geographically isolated southern-most population in Mexico, where a strong increase in population size was inferred. Analyses suggested that demographic changes in the core of the distribution occurred in association with the recolonization after the Ice Age and also by anthropogenic effects, such as the past overharvest of the species for fertilizer or the current use of the animals as bait for American eel (Anguilla rostrata) and whelk (Busycon spp.) fisheries. This study highlights the importance of considering both climatic changes and anthropogenic effects in efforts to understand population dynamics-a topic which is highly relevant in the ongoing assessments of the effects of climate change and overharvest. ?? 2010 Blackwell Publishing Ltd.

Population dynamics of American horseshoe crabs--historic climatic events and recent anthropogenic pressures.

PubMed

Faurby, Søren; King, Tim L; Obst, Matthias; Hallerman, Eric M; Pertoldi, Cino; Funch, Peter

2010-08-01

Populations of the American horseshoe crab, Limulus polyphemus, have declined, but neither the causes nor the magnitude are fully understood. In order to evaluate historic demography, variation at 12 microsatellite DNA loci surveyed in 1218 L. polyphemus sampled from 28 localities was analysed with Bayesian coalescent-based methods. The analysis showed strong declines in population sizes throughout the species' distribution except in the geographically isolated southern-most population in Mexico, where a strong increase in population size was inferred. Analyses suggested that demographic changes in the core of the distribution occurred in association with the recolonization after the Ice Age and also by anthropogenic effects, such as the past overharvest of the species for fertilizer or the current use of the animals as bait for American eel (Anguilla rostrata) and whelk (Busycon spp.) fisheries. This study highlights the importance of considering both climatic changes and anthropogenic effects in efforts to understand population dynamics--a topic which is highly relevant in the ongoing assessments of the effects of climate change and overharvest.

The more the heavier? Family size and childhood obesity in the U.S.

PubMed

Datar, Ashlesha

2017-05-01

Childhood obesity remains a top public health concern and understanding its drivers is important for combating this epidemic. Contemporaneous trends in declining family size and increasing childhood obesity in the U.S. suggest that family size may be a potential contributor, but limited evidence exists. Using data from a national sample of children in the U.S. this study examines whether family size, measured by the number of siblings a child has, is associated with child BMI and obesity, and the possible mechanisms at work. The potential endogeneity of family size is addressed by using several complementary approaches including sequentially introducing of a rich set of controls, subgroup analyses, and estimating school fixed-effects and child fixed-effects models. Results suggest that having more siblings is associated with significantly lower BMI and lower likelihood of obesity. Children with siblings have healthier diets and watch less television. Family mealtimes, less eating out, reduced maternal work, and increased adult supervision of children are potential mechanisms through which family size is protective of childhood obesity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of additive on Zeta potential and particle size of nickel nanoparticles

NASA Astrophysics Data System (ADS)

Sharma, Vikash; Tarachand, Chotia, Chandrabhan; Okram, G. S.

2017-05-01

Nickel nanoparticles (NPs) were prepared by thermal decomposition method using Oleylamine (OLY) as a solvent and Trioctylphosphine (TOP) as a surfactant. We have investigated the effect of pH and addition of Ethylenediamine tetraacetic acid (EDTA) on the stability and particle size of Ni NPs using zeta potential and particle size analyser. Coating of the surfactants on the surface of Ni NPs was confirmed by Fourier transform infrared (FTIR) spectroscopy. Autotitration study of zeta potential of these NPs in ethanol by dynamic light scattering (DLS) at different pH values confirmed an isoelectric point (IEP) at pH = 3.64 in ethanol and pH = 3.04 after addition of EDTA in ethanol. It was observed that addition of EDTA in nanosuspension enhances stability of Ni-NPs significantly.

Preparation and optical characteristics of ZnSe nanocrystals doped glass by sol gel in situ crystallization method

NASA Astrophysics Data System (ADS)

Hao, Haiyan; Yao, Xi; Wang, Minqiang

2007-01-01

Homogeneous ZnSe nanocrystals doped SiO 2 glass was successfully prepared by sol-gel in situ crystallization method. The structure of the doped ZnSe nanocrystals was studied by X-ray diffraction (XRD). ZnSe nanocrystals in silica were about 4-10 nm analysed by transmission electron microscopy (TEM), which was consistent with the results of XRD estimated using Scherrer's formular. The quantum size effect in ZnSe nanocrystals was evidenced from the blue-shifts of the optical absorption edge, and the average size of ZnSe nanocrystals was estimated by the magnitude of blue shift according to the L.E. Brus' effective mass model. The size of ZnSe nanocrystals depending on annealing time and temperature was further discussed using XRF.

Effects of augmentative and alternative communication on challenging behavior: a meta-analysis.

PubMed

Walker, Virginia L; Snell, Martha E

2013-06-01

The purposes of this review were to (a) use meta-analytic procedures to examine the effectiveness of single-case AAC intervention research on challenging behaviors exhibited by individuals with disabilities, (b) identify study characteristics that moderate intervention effects, and (c) evaluate the quality of research. The authors provided inferential and descriptive analyses of 54 studies representing 111 participants and estimated effect sizes using the Nonoverlap of All Pairs (NAP) method. Overall, AAC interventions were found to be equally effective across a broad spectrum of participants and interventions. AAC interventions were more effective with younger children than with adults. Interventions in which functional behavior assessments (FBA) were used had significantly larger effect sizes than those that did not use FBAs. Further, functional communication training interventions resulted in larger effect sizes than Picture Exchange Communication System interventions. Descriptive analysis revealed that (a) interventions often occurred in atypical environments (e.g., therapy room, experimental room) and with atypical interventionists (e.g., therapists, researchers), and (b) numerous studies did not exhibit quality characteristics of single-case research.

The effectiveness of element downsizing on a three-dimensional finite element model of bone trabeculae in implant biomechanics.

PubMed

Sato, Y; Wadamoto, M; Tsuga, K; Teixeira, E R

1999-04-01

More validity of finite element analysis in implant biomechanics requires element downsizing. However, excess downsizing needs computer memory and calculation time. To investigate the effectiveness of element downsizing on the construction of a three-dimensional finite element bone trabeculae model, with different element sizes (600, 300, 150 and 75 microm) models were constructed and stress induced by vertical 10 N loading was analysed. The difference in von Mises stress values between the models with 600 and 300 microm element sizes was larger than that between 300 and 150 microm. On the other hand, no clear difference of stress values was detected among the models with 300, 150 and 75 microm element sizes. Downsizing of elements from 600 to 300 microm is suggested to be effective in the construction of a three-dimensional finite element bone trabeculae model for possible saving of computer memory and calculation time in the laboratory.

Influence of spaceflight on rat skeletal muscle

NASA Technical Reports Server (NTRS)

Martin, Thomas P.; Edgerton, V. Reggie; Grindeland, Richard E.

1988-01-01

The effect of a 7-day spaceflight (aboard NASA's SL-3) on the size and the metabolism of single fibers from several rat muscles was investigated along with the specificity of these responses as related to the muscle type and the size of fibers. It was found that the loss of mass after flight was varied from 36 percent in the soleus to 15 percent in the extensor digitorum longus. Results of histochemical analyses showed that the succinate dehydrogenase (SDH) activity in muscles of flight-exposed rats was maintained at the control levels, whereas the alpha-glycerol phosphate dehydrogenase (GPD) activity was either maintained or increased. The analyses of the metabolic profiles of ATPase, SDH, and GPD indicated that, in some muscles, there was an increase in the poportion of fast oxidative-glycolytic fibers.

Simulating the Structural Response of a Preloaded Bolted Joint

NASA Technical Reports Server (NTRS)

Knight, Norman F., Jr.; Phillips, Dawn R.; Raju, Ivatury S.

2008-01-01

The present paper describes the structural analyses performed on a preloaded bolted-joint configuration. The joint modeled was comprised of two L-shaped structures connected together using a single bolt. Each L-shaped structure involved a vertical flat segment (or shell wall) welded to a horizontal segment (or flange). Parametric studies were performed using elasto-plastic, large-deformation nonlinear finite element analyses to determine the influence of several factors on the bolted-joint response. The factors considered included bolt preload, washer-surface-bearing size, edge boundary conditions, joint segment length, and loading history. Joint response is reported in terms of displacements, gap opening, and surface strains. Most of the factors studied were determined to have minimal effect on the bolted-joint response; however, the washer-bearing-surface size affected the response significantly.

Sexual dimorphism in human cranial trait scores: effects of population, age, and body size.

PubMed

Garvin, Heather M; Sholts, Sabrina B; Mosca, Laurel A

2014-06-01

Sex estimation from the skull is commonly performed by physical and forensic anthropologists using a five-trait scoring system developed by Walker. Despite the popularity of this method, validation studies evaluating its accuracy across a variety of samples are lacking. Furthermore, it remains unclear what other intrinsic or extrinsic variables are related to the expression of these traits. In this study, cranial trait scores and postcranial measurements were collected from four diverse population groups (U.S. Whites, U.S. Blacks, medieval Nubians, and Arikara Native Americans) following Walker's protocols (total n = 499). Univariate and multivariate analyses were utilized to evaluate the accuracy of these traits in sex estimation, and to test for the effects of population, age, and body size on trait expressions. Results revealed significant effects of population on all trait scores. Sample-specific correct sex classification rates ranged from 74% to 94%, with an overall accuracy of 85% for the pooled sample. Classification performance varied among the traits (best for glabella and mastoid scores and worst for nuchal scores). Furthermore, correlations between traits were weak or nonsignificant, suggesting that different factors may influence individual traits. Some traits displayed correlations with age and/or postcranial size that were significant but weak, and within-population analyses did not reveal any consistent relationships between these traits across all groups. These results indicate that neither age nor body size plays a large role in trait expression, and thus does not need to be incorporated into sex estimation methods. Copyright © 2014 Wiley Periodicals, Inc.

Homoplasy and mutation model at microsatellite loci and their consequences for population genetics analysis.

PubMed

Estoup, Arnaud; Jarne, Philippe; Cornuet, Jean-Marie

2002-09-01

Homoplasy has recently attracted the attention of population geneticists, as a consequence of the popularity of highly variable stepwise mutating markers such as microsatellites. Microsatellite alleles generally refer to DNA fragments of different size (electromorphs). Electromorphs are identical in state (i.e. have identical size), but are not necessarily identical by descent due to convergent mutation(s). Homoplasy occurring at microsatellites is thus referred to as size homoplasy. Using new analytical developments and computer simulations, we first evaluate the effect of the mutation rate, the mutation model, the effective population size and the time of divergence between populations on size homoplasy at the within and between population levels. We then review the few experimental studies that used various molecular techniques to detect size homoplasious events at some microsatellite loci. The relationship between this molecularly accessible size homoplasy size and the actual amount of size homoplasy is not trivial, the former being considerably influenced by the molecular structure of microsatellite core sequences. In a third section, we show that homoplasy at microsatellite electromorphs does not represent a significant problem for many types of population genetics analyses realized by molecular ecologists, the large amount of variability at microsatellite loci often compensating for their homoplasious evolution. The situations where size homoplasy may be more problematic involve high mutation rates and large population sizes together with strong allele size constraints.

A Meta-Analysis of Resistance Training in Female Youth: Its Effect on Muscular Strength, and Shortcomings in the Literature.

PubMed

Moran, Jason; Sandercock, Gavin; Ramirez-Campillo, Rodrigo; Clark, Cain C T; Fernandes, John F T; Drury, Benjamin

2018-07-01

Resistance training is an effective way to enhance strength in female youth but, to date, no researcher has meta-analysed its effect on muscular strength in that population. This meta-analysis characterised female youths' adaptability to resistance training (RT). A second objective was to highlight the limitations of the body of literature with a view to informing future research. Google Scholar, PubMed, Web of Science. Resistance training interventions in healthy females with a mean age between 8 and 18 years. Programmes of between 4 and 16 weeks' duration that included a control group. The inverse-variance random effects model for meta-analyses was used because it allocates a proportionate weight to trials based on the size of their individual standard errors and facilitates analysis whilst accounting for heterogeneity across studies. Effect sizes, calculated from a measure of muscular strength, are represented by the standardised mean difference and are presented alongside 95% confidence intervals. The magnitude of the main effect was 'small' (0.54, 95% confidence interval: 0.23-0.85). Effect sizes were larger in older (> 15 years; ES = 0.72 [0.23-1.21] vs. 0.38 [- 0.02-0.79]), taller (> 163 cm; ES = 0.67 [0.20-1.13] vs. 0.55 [0.08-1.02]) and heavier (< 54 kg; ES = 0.67 [0.30-1.03] vs. 0.53 [- 0.00-1.06]) participants. Resistance training is effective in female youth. These findings can be used to inform the prescription of RT in female youth.

IN-STREAM AND WATERSHED PREDICTORS OF GENETIC DIVERSITY, EFFECTIVE POPULATION SIZE AND IMMIGRATION ACROSS RIVER-STREAM NETWORKS

EPA Science Inventory

The influence of spatial processes on population dynamics within river-stream networks is poorly understood. Utilizing spatially explicit analyses of temporal genetic variance, we examined whether persistence of Central Stonerollers (Campostoma anomalum) reflects differences in h...

Economic growth and marine biodiversity: influence of human social structure on decline of marine trophic levels.

PubMed

Clausen, Rebecca; York, Richard

2008-04-01

We assessed the effects of economic growth, urbanization, and human population size on marine biodiversity. We used the mean trophic level (MTL) of marine catch as an indicator of marine biodiversity and conducted cross-national time-series analyses (1960-2003) of 102 nations to investigate human social influences on fish catch and trends in MTL. We constructed path models to examine direct and indirect effects relating to marine catch and MTL. Nations' MTLs declined with increased economic growth, increased urbanization, and increased population size, in part because of associated increased catch. These findings contradict the environmental Kuznets curve hypothesis, which claims that economic modernization will reduce human impact on the environment. To make informed decisions on issues of marine resource management, policy makers, nonprofit entities, and professional societies must recognize the need to include social analyses in overall conservation-research strategies. The challenge is to utilize the socioeconomic and ecological research in the service of a comprehensive marine-conservation movement.

Coordinate based random effect size meta-analysis of neuroimaging studies.

PubMed

Tench, C R; Tanasescu, Radu; Constantinescu, C S; Auer, D P; Cottam, W J

2017-06-01

Low power in neuroimaging studies can make them difficult to interpret, and Coordinate based meta-analysis (CBMA) may go some way to mitigating this issue. CBMA has been used in many analyses to detect where published functional MRI or voxel-based morphometry studies testing similar hypotheses report significant summary results (coordinates) consistently. Only the reported coordinates and possibly t statistics are analysed, and statistical significance of clusters is determined by coordinate density. Here a method of performing coordinate based random effect size meta-analysis and meta-regression is introduced. The algorithm (ClusterZ) analyses both coordinates and reported t statistic or Z score, standardised by the number of subjects. Statistical significance is determined not by coordinate density, but by a random effects meta-analyses of reported effects performed cluster-wise using standard statistical methods and taking account of censoring inherent in the published summary results. Type 1 error control is achieved using the false cluster discovery rate (FCDR), which is based on the false discovery rate. This controls both the family wise error rate under the null hypothesis that coordinates are randomly drawn from a standard stereotaxic space, and the proportion of significant clusters that are expected under the null. Such control is necessary to avoid propagating and even amplifying the very issues motivating the meta-analysis in the first place. ClusterZ is demonstrated on both numerically simulated data and on real data from reports of grey matter loss in multiple sclerosis (MS) and syndromes suggestive of MS, and of painful stimulus in healthy controls. The software implementation is available to download and use freely. Copyright © 2017 Elsevier Inc. All rights reserved.

Dislocation, crystallite size distribution and lattice strain of magnesium oxide nanoparticles

NASA Astrophysics Data System (ADS)

Sutapa, I. W.; Wahid Wahab, Abdul; Taba, P.; Nafie, N. L.

2018-03-01

The oxide of magnesium nanoparticles synthesized using sol-gel method and analysis of the structural properties was conducted. The functional groups of nanoparticles has been analysed by Fourier Transform Infrared Spectroscopy (FT-IR). Dislocations, average size of crystal, strain, stress, the energy density of crystal, crystallite size distribution and morphologies of the crystals were determined based on X-ray diffraction profile analysis. The morphological of the crystal was analysed based on the image resulted from SEM analysis. The crystallite size distribution was calculated with the contention that the particle size has a normal logarithmic form. The most orientations of crystal were determined based on the textural crystal from diffraction data of X-ray diffraction profile analysis. FT-IR results showed the stretching vibration mode of the Mg-O-Mg in the range of 400.11-525 cm-1 as a broad band. The average size crystal of nanoparticles resulted is 9.21 mm with dislocation value of crystal is 0.012 nm-2. The strains, stress, the energy density of crystal are 1.5 x 10-4 37.31 MPa; 0.72 MPa respectively. The highest texture coefficient value of the crystal is 0.98. This result is supported by morphological analysis using SEM which shows most of the regular cubic-shaped crystals. The synthesis method is suitable for simple and cost-effective synthesis model of MgO nanoparticles.

Tests of size and growth effects on Arctic charr (Salvelinus alpinus) otolith δ18 O and δ13 C values.

PubMed

Burbank, J; Kelly, B; Nilsson, J; Power, M

2018-06-06

Otolith δ 18 O and δ 13 C values have been used extensively to reconstruct thermal and diet histories. Researchers have suggested that individual growth rate and size may have an effect on otolith isotope ratios and subsequently confound otolith based thermal and diet reconstructions. As few explicit tests of the effect of fish in freshwater environments exist, here we determine experimentally the potential for related growth rate and size effects on otolith δ 18 O and δ 13 C values. Fifty Arctic charr were raised in identical conditions for two years after which their otoliths were removed and analyzed for their δ 18 O and δ 13 C values. The potential effects of final length and the Thermal Growth Coefficient (TGC) on otolith isotope ratios were tested using correlation and regression analysis to determine if significant effects were present and to quantify effects when present. The analyses indicated that TGC and size had significant and similar positive non-linear relationships with δ 13 C values and explained 35% and 42% of the variability, respectively. Conversely, both TGC and size were found to have no significant correlation with otolith δ 18 O values. There was no significant correlation between δ 18 O and δ 13 C values. The investigation indicated the presence of linked growth rate and size effects on otolith δ 13 C values, the nature of which requires further study. Otolith δ 18 O values were unaffected by individual growth rate and size, confirming the applicability of applying these values to thermal reconstructions of fish habitat. This article is protected by copyright. All rights reserved.

Electrical Characteristics CuFe2O4 Thick Film Ceramics Made with Different Screen Size Utiizing Fe2O3 Nanopowder Derived from Yarosite for NTC Thermistor

NASA Astrophysics Data System (ADS)

Wiendartun, Syarif, Dani Gustaman

2010-10-01

Fabrication of CuFe2O4 thick film ceramics utilizing Fe2O3 derived from yarosite using screen printing technique for NTC thermistor has been carried out. Effect of thickness variation due to different size of screen (screen 225; 300 and 375 mesh) has been studied. X-ray diffraction analyses (XRD) was done to know crystal structure and phases formation. SEM analyses was carried out to know microstructure of the films. Electrical properties characterization was done through measurement of electrical resistance at various temperatures (room temperature to 100° C). The XRD data showed that the films crystalize in tetragonal spinel. The SEM images showed that the screen with the smaller of the hole size, made the grain size was bigger. Electrical data showed that the larger the screen different size thickness variation (mesh), the larger the resistance, thermistor constant and sensitivity. From the electrical characteristics data, it was known that the electrical characteristics of the CuFe2O4 thick film ceramics followed the NTC characteristic. The value of B and RRT of the produced CuFe2O4 ceramics namely B = 3241-3484 K and RRT = 25.6-87.0 M Ohm, fitted market requirement.

Lowering sample size in comparative analyses can indicate a correlation where there is none: example from Rensch's rule in primates.

PubMed

Lindenfors, P; Tullberg, B S

2006-07-01

The fact that characters may co-vary in organism groups because of shared ancestry and not always because of functional correlations was the initial rationale for developing phylogenetic comparative methods. Here we point out a case where similarity due to shared ancestry can produce an undesired effect when conducting an independent contrasts analysis. Under special circumstances, using a low sample size will produce results indicating an evolutionary correlation between characters where an analysis of the same pattern utilizing a larger sample size will show that this correlation does not exist. This is the opposite effect of increased sample size to that expected; normally an increased sample size increases the chance of finding a correlation. The situation where the problem occurs is when co-variation between the two continuous characters analysed is clumped in clades; e.g. when some phylogenetically conservative factors affect both characters simultaneously. In such a case, the correlation between the two characters becomes contingent on the number of clades sharing this conservative factor that are included in the analysis, in relation to the number of species contained within these clades. Removing species scattered evenly over the phylogeny will in this case remove the exact variation that diffuses the evolutionary correlation between the two characters - the variation contained within the clades sharing the conservative factor. We exemplify this problem by discussing a parallel in nature where the described problem may be of importance. This concerns the question of the presence or absence of Rensch's rule in primates.

Women and Men Together in Recruit Training.

PubMed

Orme, Geoffrey J; Kehoe, E James

2018-05-01

Although men and women recruits to the Australian Army have trained in mixed-gender platoons since 1995, restrictions on women joining the combat arms were only removed in 2016. As part of a longitudinal study starting with recruit training, this article examined recruit records collected before 2016 with the aims of delineating (1) the relative performance of women versus men in mixed-gender platoons and (2) the relative performance of men in mixed-gender platoons versus all-male platoons. De-identified instructor ratings for 630 females and 4,505 males who completed training between 2011 and 2015 were obtained. Recruits were distributed across 128 platoons (averaging 41.6 members, SD = 8.3) of which 75% contained females, in proportions from 5% to 45%. These analyses were conducted under defense ethics approval DPR-LREP 069-15. Factor analyses revealed that instructor ratings generally loaded onto a single factor, accounting 77.2% of the variance. Consequently, a composite recruit performance score (range 1-5) was computed for 16 of 19 competencies. Analyses of the scores revealed that the distributions of the scores for females and males overlapped considerably. Observed effects were negligible to small in size. The distributions were all centered between 3.0 and 3.5. In mixed-gender platoons, 51% of the females and 52% of the males fell in this band, and 44% of recruits in all-male platoons had scores in this band. The lower three bands (1.0-3.0) contained a slightly greater proportion of females (18%) than males in either mixed-gender platoons (12%) or all-male platoons (12%). Conversely, the upper three bands (3.5-5.0) contained a slightly smaller percentage of females (31%) than males in either mixed-gender platoons (36%) or all-male platoons (44%). Although scores for females were reliably lower than those of males in mixed-gender platoons, χ2 (4) = 16.01, p < 0.01, the effect size (V = 0.07) did not reach the criterion for even a small effect (0.10). For male recruits, those in mixed-gender platoons had scores that were reliably lower than in all-male platoons, χ2 (4) = 48.38, p < 0.001; its effect size (V = 0.11) just exceeded the criterion for a small effect (0.10). Further analyses revealed that male scores had a near-zero correlation (r = -0.033) with the proportion of females in platoons (0-45%). This large-scale secondary analysis of instructor ratings of female and male recruits provides a platform for monitoring the integration of women into the combat arms. The analyses revealed nearly complete overlap in the performance of female versus male recruits. The detected gender-related differences were negligible to small in size. These small differences must be viewed with considerable caution. They may be artifacts of rater bias or other uncontrolled features of the rating system, which was designed for reporting individual recruit performance rather than aggregate analyses. Even with these limitations, this baseline snapshot of recruit performance suggests that, at recruit training, women and men are already working well together, which bodes well for their subsequent integration into the combat arms.

Power and sample size for multivariate logistic modeling of unmatched case-control studies.

PubMed

Gail, Mitchell H; Haneuse, Sebastien

2017-01-01

Sample size calculations are needed to design and assess the feasibility of case-control studies. Although such calculations are readily available for simple case-control designs and univariate analyses, there is limited theory and software for multivariate unconditional logistic analysis of case-control data. Here we outline the theory needed to detect scalar exposure effects or scalar interactions while controlling for other covariates in logistic regression. Both analytical and simulation methods are presented, together with links to the corresponding software.

Effective population size dynamics reveal impacts of historic climatic events and recent anthropogenic pressure in African elephants.

PubMed

Okello, J B A; Wittemyer, G; Rasmussen, H B; Arctander, P; Nyakaana, S; Douglas-Hamilton, I; Siegismund, H R

2008-09-01

Two hundred years of elephant hunting for ivory, peaking in 1970-1980s, caused local extirpations and massive population declines across Africa. The resulting genetic impacts on surviving populations have not been studied, despite the importance of understanding the evolutionary repercussions of such human-mediated events on this keystone species. Using Bayesian coalescent-based genetic methods to evaluate time-specific changes in effective population size, we analysed genetic variation in 20 highly polymorphic microsatellite loci from 400 elephants inhabiting the greater Samburu-Laikipia region of northern Kenya. This area experienced a decline of between 80% and 90% in the last few decades when ivory harvesting was rampant. The most significant change in effective population size, however, occurred approximately 2500 years ago during a mid-Holocene period of climatic drying in tropical Africa. Contrary to expectations, detailed analyses of four contemporary age-based cohorts showed that the peak poaching epidemic in the 1970s caused detectable temporary genetic impacts, with genetic diversity rebounding as juveniles surviving the poaching era became reproductively mature. This study demonstrates the importance of climatic history in shaping the distribution and genetic history of a keystone species and highlights the utility of coalescent-based demographic approaches in unravelling ancestral demographic events despite a lack of ancient samples. Unique insights into the genetic signature of mid-Holocene climatic change in Africa and effects of recent poaching pressure on elephants are discussed.

Copper Decoration of Carbon Nanotubes and High Resolution Electron Microscopy

NASA Astrophysics Data System (ADS)

Probst, Camille

A new process of decorating carbon nanotubes with copper was developed for the fabrication of nanocomposite aluminum-nanotubes. The process consists of three stages: oxidation, activation and electroless copper plating on the nanotubes. The oxidation step was required to create chemical function on the nanotubes, essential for the activation step. Then, catalytic nanoparticles of tin-palladium were deposited on the tubes. Finally, during the electroless copper plating, copper particles with a size between 20 and 60 nm were uniformly deposited on the nanotubes surface. The reproducibility of the process was shown by using another type of carbon nanotube. The fabrication of nanocomposites aluminum-nanotubes was tested by aluminum vacuum infiltration. Although the infiltration of carbon nanotubes did not produce the expected results, an interesting electron microscopy sample was discovered during the process development: the activated carbon nanotubes. Secondly, scanning transmitted electron microscopy (STEM) imaging in SEM was analysed. The images were obtained with a new detector on the field emission scanning electron microscope (Hitachi S-4700). Various parameters were analysed with the use of two different samples: the activated carbon nanotubes (previously obtained) and gold-palladium nanodeposits. Influences of working distance, accelerating voltage or sample used on the spatial resolution of images obtained with SMART (Scanning Microscope Assessment and Resolution Testing) were analysed. An optimum working distance for the best spatial resolution related to the sample analysed was found for the imaging in STEM mode. Finally, relation between probe size and spatial resolution of backscattered electrons (BSE) images was studied. An image synthesis method was developed to generate the BSE images from backscattered electrons coefficients obtained with CASINO software. Spatial resolution of images was determined using SMART. The analysis shown that using a probe size smaller than the size of the observed object (sample features) does not improve the spatial resolution. In addition, the effects of the accelerating voltage, the current intensity and the sample geometry and composition were analysed.

Effects of accelerated ageing on viability, leachate exudation, and fatty acid content of Dalbergia sissoo Roxb

Treesearch

R.C. Thapliyal; K.F. Connor

1997-01-01

Accelerated ageing of seeds of Dalbergia sissoo Roxb., a multi-purpose tropical legume tree, was effective as a vigour test only at temperatures in excess of 43 deg C for 72 h. Increased leakage of solutes accompanied the decrease in viability, but there was no relationship between seed size and conductivity. Analyses of D. sissoo...

Exercise improves depressive symptoms in older adults: An umbrella review of systematic reviews and meta-analyses.

PubMed

Catalan-Matamoros, Daniel; Gomez-Conesa, Antonia; Stubbs, Brendon; Vancampfort, Davy

2016-10-30

Late-life depression is a growing public health concern. Exercise may be of added value but the literature remains equivocal. We conducted a systematic overview of meta-analyses and an exploratory pooled analysis of previous meta-analyses to determine the effect of exercise on depression in older adults. Two independent researchers searched Pubmed, CINAHL, Cochrane Plus, PsycArticles, and PsycInfo for meta-analyses on exercise in late-life depression. Methodological quality was assessed using the Assessment of Multiple Systematic Reviews (AMSTAR) Instrument. We pooled effect sizes from previous meta-analyses of randomized controlled trials to determine the effect of exercise on depression in older adults. The systematic review yielded 3 meta-analyses. In total, 16 unique cohorts of 1487 participants were included. The quality of the three included meta-analyses was considered as "moderate" according to AMSTAR scores. No serious adverse events were reported. Compared to controls (n=583), those exercising (n=541) significantly reduced depressive symptoms. Our umbrella review indicates that exercise is safe and efficacious in reducing depressive symptoms in older people. Since exercise has many other known health benefits, it should be considered as a core intervention in the multidisciplinary treatment of older adults experiencing depression. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Systematic review of quality of life and functional outcomes in randomized placebo-controlled studies of medications for attention-deficit/hyperactivity disorder.

PubMed

Coghill, David R; Banaschewski, Tobias; Soutullo, César; Cottingham, Matthew G; Zuddas, Alessandro

2017-11-01

Children, adolescents and adults with attention-deficit/hyperactivity disorder (ADHD) experience functional impairment and poor health-related quality of life (HRQoL) in addition to symptoms of inattention/hyperactivity-impulsivity. To synthesize qualitatively the published evidence from randomized, double-blind, placebo-controlled trials of the effectiveness of pharmacotherapy on functional impairment or HRQoL in patients with ADHD, a systematic PubMed searching and screening strategy was designed to identify journal articles meeting pre-specified criteria. Post hoc analyses and meta-analyses were excluded. HRQoL outcomes, functional outcomes and the principal ADHD symptom-based outcome were extracted from included studies. An effect size of 0.5 versus placebo was used as a threshold for potential clinical relevance (unreported effect sizes were calculated when possible). Of 291 records screened, 35 articles describing 34 studies were included. HRQoL/functioning was usually self-rated in adults and proxy-rated in children/adolescents. Baseline data indicated substantial HRQoL deficits in children/adolescents. Placebo-adjusted effects of medication on ADHD symptoms, HRQoL and functioning, respectively, were statistically or nominally significant in 18/18, 10/12 and 7/9 studies in children/adolescents and 14/16, 9/11 and 9/10 studies in adults. Effect sizes were ≥0.5 versus placebo for symptoms, HRQoL and functioning, respectively, in 14/16, 7/9 and 4/8 studies in children/adolescents; and 6/12, 1/6 and 1/8 studies in adults. Effect sizes were typically larger for stimulants than for non-stimulants, for symptoms than for HRQoL/functioning, and for children/adolescents than for adults. The efficacy of ADHD medication extends beyond symptom control and may help reduce the related but distinct functional impairments and HRQoL deficits in patients with ADHD.

Exosomes secreted by placental stem cells selectively inhibit growth of aggressive prostate cancer cells.

PubMed

Peak, Taylor C; Praharaj, Prakash P; Panigrahi, Gati K; Doyle, Michael; Su, Yixin; Schlaepfer, Isabel R; Singh, Ravi; Vander Griend, Donald J; Alickson, Julie; Hemal, Ashok; Atala, Anthony; Deep, Gagan

2018-05-23

The current paradigm in the development of new cancer therapies is the ability to target tumor cells while avoiding harm to noncancerous cells. Furthermore, there is a need to develop novel therapeutic options against drug-resistant cancer cells. Herein, we characterized the placental-derived stem cell (PLSC) exosomes (PLSC Exo ) and evaluated their anti-cancer efficacy in prostate cancer (PCa) cell lines. Nanoparticle tracking analyses revealed the size distribution (average size 131.4 ± 0.9 nm) and concentration of exosomes (5.23 × 10 10 ±1.99 × 10 9 per ml) secreted by PLSC. PLSC Exo treatment strongly inhibited the viability of enzalutamide-sensitive and -resistant PCa cell lines (C4-2B, CWR-R1, and LNCaP cells). Interestingly, PLSC Exo treatment had no effect on the viability of a non-neoplastic human prostate cell line (PREC-1). Mass spectrometry (MS) analyses showed that PLSC Exo are loaded with 241 proteins and mainly with saturated fatty acids. Further, Ingenuity Pathway Analysis analyses of proteins loaded in PLSC Exo suggested the role of retinoic acid receptor/liver x receptor pathways in their biological effects. Together, these results suggest the novel selective anti-cancer effects of PLSC Exo against aggressive PCa cells. Copyright © 2018 Elsevier Inc. All rights reserved.

The effects of 'ecstasy' (MDMA) on visuospatial memory performance: findings from a systematic review with meta-analyses.

PubMed

Murphy, Philip N; Bruno, Raimondo; Ryland, Ida; Wareing, Michele; Fisk, John E; Montgomery, Catharine; Hilton, Joanne

2012-03-01

To review, with meta-analyses where appropriate, performance differences between ecstasy (3,4-methylenedioxymethamphetamine) users and non-users on a wider range of visuospatial tasks than previously reviewed. Such tasks have been shown to draw upon working memory executive resources. Abstract databases were searched using the United Kingdom National Health Service Evidence Health Information Resource. Inclusion criteria were publication in English language peer-reviewed journals and the reporting of new findings regarding human ecstasy-users' performance on visuospatial tasks. Data extracted included specific task requirements to provide a basis for meta-analyses for categories of tasks with similar requirements. Fifty-two studies were identified for review, although not all were suitable for meta-analysis. Significant weighted mean effect sizes indicating poorer performance by ecstasy users compared with matched controls were found for tasks requiring recall of spatial stimulus elements, recognition of figures and production/reproduction of figures. There was no evidence of a linear relationship between estimated ecstasy consumption and effect sizes. Given the networked nature of processing for spatial and non-spatial visual information, future scanning and imaging studies should focus on brain activation differences between ecstasy users and non-users in the context of specific tasks to facilitate identification of loci of potentially compromised activity in users. Copyright © 2012 John Wiley & Sons, Ltd.

Confounding compression: the effects of posture, sizing and garment type on measured interface pressure in sports compression clothing.

PubMed

Brophy-Williams, Ned; Driller, Matthew William; Shing, Cecilia Mary; Fell, James William; Halson, Shona Leigh; Halson, Shona Louise

2015-01-01

The purpose of this investigation was to measure the interface pressure exerted by lower body sports compression garments, in order to assess the effect of garment type, size and posture in athletes. Twelve national-level boxers were fitted with sports compression garments (tights and leggings), each in three different sizes (undersized, recommended size and oversized). Interface pressure was assessed across six landmarks on the lower limb (ranging from medial malleolus to upper thigh) as athletes assumed sitting, standing and supine postures. Sports compression leggings exerted a significantly higher mean pressure than sports compression tights (P < 0.001). Oversized tights applied significantly less pressure than manufacturer-recommended size or undersized tights (P < 0.001), yet no significant differences were apparent between different-sized leggings. Standing posture resulted in significantly higher mean pressure application than a seated posture for both tights and leggings (P < 0.001 and P = 0.002, respectively). Pressure was different across landmarks, with analyses revealing a pressure profile that was neither strictly graduated nor progressive in nature. The pressure applied by sports compression garments is significantly affected by garment type, size and posture assumed by the wearer.

Revisiting sample size: are big trials the answer?

PubMed

Lurati Buse, Giovanna A L; Botto, Fernando; Devereaux, P J

2012-07-18

The superiority of the evidence generated in randomized controlled trials over observational data is not only conditional to randomization. Randomized controlled trials require proper design and implementation to provide a reliable effect estimate. Adequate random sequence generation, allocation implementation, analyses based on the intention-to-treat principle, and sufficient power are crucial to the quality of a randomized controlled trial. Power, or the probability of the trial to detect a difference when a real difference between treatments exists, strongly depends on sample size. The quality of orthopaedic randomized controlled trials is frequently threatened by a limited sample size. This paper reviews basic concepts and pitfalls in sample-size estimation and focuses on the importance of large trials in the generation of valid evidence.

50 years of rational‐emotive and cognitive‐behavioral therapy: A systematic review and meta‐analysis

PubMed Central

Cotet, Carmen; Matu, Silviu; Mogoase, Cristina; Stefan, Simona

2017-01-01

Objective Rational emotive behavior therapy (REBT), introduced by Albert Ellis in the late 1950s, is one of the main pillars of cognitive‐behavioral therapy. Existing reviews on REBT are overdue by 10 years or more. We aimed to summarize the effectiveness and efficacy of REBT since its beginnings and investigate the alleged mechanisms of change. Method Systematic search identified 84 articles, out of which 68 provided data for between‐group analyses and 39 for within‐group analyses. Results We found a medium effect size of REBT compared to other interventions on outcomes (d = 0.58) and on irrational beliefs (d = 0.70), at posttest. For the within‐group analyses, we obtained medium effects for both outcomes (d = 0.56) and irrational beliefs (d = 0.61). Several significant moderators emerged. Conclusion REBT is a sound psychological intervention. Directions for future studies are outlined, stemming from the limitations of existing ones. PMID:28898411

Comparative Efficacy of Seven Psychotherapeutic Interventions for Patients with Depression: A Network Meta-Analysis

PubMed Central

Gerger, Heike; Nüesch, Eveline; Trelle, Sven; Znoj, Hansjörg; Jüni, Peter; Cuijpers, Pim

2013-01-01

Background Previous meta-analyses comparing the efficacy of psychotherapeutic interventions for depression were clouded by a limited number of within-study treatment comparisons. This study used network meta-analysis, a novel methodological approach that integrates direct and indirect evidence from randomised controlled studies, to re-examine the comparative efficacy of seven psychotherapeutic interventions for adult depression. Methods and Findings We conducted systematic literature searches in PubMed, PsycINFO, and Embase up to November 2012, and identified additional studies through earlier meta-analyses and the references of included studies. We identified 198 studies, including 15,118 adult patients with depression, and coded moderator variables. Each of the seven psychotherapeutic interventions was superior to a waitlist control condition with moderate to large effects (range d = −0.62 to d = −0.92). Relative effects of different psychotherapeutic interventions on depressive symptoms were absent to small (range d = 0.01 to d = −0.30). Interpersonal therapy was significantly more effective than supportive therapy (d = −0.30, 95% credibility interval [CrI] [−0.54 to −0.05]). Moderator analysis showed that patient characteristics had no influence on treatment effects, but identified aspects of study quality and sample size as effect modifiers. Smaller effects were found in studies of at least moderate (Δd = 0.29 [−0.01 to 0.58]; p = 0.063) and large size (Δd = 0.33 [0.08 to 0.61]; p = 0.012) and those that had adequate outcome assessment (Δd = 0.38 [−0.06 to 0.87]; p = 0.100). Stepwise restriction of analyses by sample size showed robust effects for cognitive-behavioural therapy, interpersonal therapy, and problem-solving therapy (all d>0.46) compared to waitlist. Empirical evidence from large studies was unavailable or limited for other psychotherapeutic interventions. Conclusions Overall our results are consistent with the notion that different psychotherapeutic interventions for depression have comparable benefits. However, the robustness of the evidence varies considerably between different psychotherapeutic treatments. Please see later in the article for the Editors' Summary PMID:23723742

The effect of texture and grain size on improving the mechanical properties of Mg-Al-Zn alloys by friction stir processing.

PubMed

Peng, Jinhua; Zhang, Zhen; Liu, Zhao; Li, Yaozu; Guo, Peng; Zhou, Wei; Wu, Yucheng

2018-03-08

Friction stir processing (FSP) was used to achieve grain refinement on Mg-Al-Zn alloys, which also brought in significant texture modification. The different micro-texture characteristics were found to cause irregular micro-hardness distribution in FSPed region. The effects of texture and grain size were investigated by comparative analyses with strongly textured rolling sheet. Grain refinement improved both strength and elongation in condition of a basal texture while such led to an increment in yield stress and a drop in elongation and ultimate stress when the basal texture was modified by FSP.

An umbrella review of meta-analyses of interventions to improve maternal outcomes for teen mothers.

PubMed

SmithBattle, Lee; Loman, Deborah G; Chantamit-O-Pas, Chutima; Schneider, Joanne Kraenzle

2017-08-01

The purpose of this study was to perform an umbrella review of meta-analyses of intervention studies designed to improve outcomes of pregnant or parenting teenagers. An extensive search retrieved nine reports which provided 21 meta-analyses analyses. Data were extracted by two reviewers. Methodological quality was assessed using the AMSTAR Instrument. Most effect sizes were small but high quality studies showed significant outcomes for reduced low birth weight (RR = 0.60), repeat pregnancies/births (OR = 0.47-0.62), maternal education (OR = 1.21-1.83), and maternal employment (OR = 1.26). Several parenting outcomes (parent-child teaching interaction post-intervention [SMD = -0.91] and at follow-up [SMD = -1.07], and parent-child relationship post-intervention [SMD = -0.71] and at follow-up [SMD = -0.90]) were significant, but sample sizes were very small. Many reports did not include moderator analyses. Behavioral interventions offer limited resources and occur too late to mitigate the educational and social disparities that precede teen pregnancy. Future intervention research and policies that redress the social determinants of early childbearing are recommended. Copyright © 2017 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Fossils and living taxa agree on patterns of body mass evolution: a case study with Afrotheria.

PubMed

Puttick, Mark N; Thomas, Gavin H

2015-12-22

Most of life is extinct, so incorporating some fossil evidence into analyses of macroevolution is typically seen as necessary to understand the diversification of life and patterns of morphological evolution. Here we test the effects of inclusion of fossils in a study of the body size evolution of afrotherian mammals, a clade that includes the elephants, sea cows and elephant shrews. We find that the inclusion of fossil tips has little impact on analyses of body mass evolution; from a small ancestral size (approx. 100 g), there is a shift in rate and an increase in mass leading to the larger-bodied Paenungulata and Tubulidentata, regardless of whether fossils are included or excluded from analyses. For Afrotheria, the inclusion of fossils and morphological character data affect phylogenetic topology, but these differences have little impact upon patterns of body mass evolution and these body mass evolutionary patterns are consistent with the fossil record. The largest differences between our analyses result from the evolutionary model, not the addition of fossils. For some clades, extant-only analyses may be reliable to reconstruct body mass evolution, but the addition of fossils and careful model selection is likely to increase confidence and accuracy of reconstructed macroevolutionary patterns. © 2015 The Authors.

Fossils and living taxa agree on patterns of body mass evolution: a case study with Afrotheria

PubMed Central

Puttick, Mark N.; Thomas, Gavin H.

2015-01-01

Most of life is extinct, so incorporating some fossil evidence into analyses of macroevolution is typically seen as necessary to understand the diversification of life and patterns of morphological evolution. Here we test the effects of inclusion of fossils in a study of the body size evolution of afrotherian mammals, a clade that includes the elephants, sea cows and elephant shrews. We find that the inclusion of fossil tips has little impact on analyses of body mass evolution; from a small ancestral size (approx. 100 g), there is a shift in rate and an increase in mass leading to the larger-bodied Paenungulata and Tubulidentata, regardless of whether fossils are included or excluded from analyses. For Afrotheria, the inclusion of fossils and morphological character data affect phylogenetic topology, but these differences have little impact upon patterns of body mass evolution and these body mass evolutionary patterns are consistent with the fossil record. The largest differences between our analyses result from the evolutionary model, not the addition of fossils. For some clades, extant-only analyses may be reliable to reconstruct body mass evolution, but the addition of fossils and careful model selection is likely to increase confidence and accuracy of reconstructed macroevolutionary patterns. PMID:26674947

The Primacy of Cognition in Schizophrenia

ERIC Educational Resources Information Center

Heinrichs, R. Walter

2005-01-01

Cognitive tasks and concepts are used increasingly in schizophrenia science and treatment. Recent meta-analyses show that across a spectrum of research domains only cognitive measures distinguish a majority of schizophrenia patients from healthy people. Average effect sizes derived from common clinical tests of attention, memory, language, and…

Electrocatalytic performance of Pt nanoparticles sputter-deposited on indium tin oxide toward methanol oxidation reaction: The particle size effect

NASA Astrophysics Data System (ADS)

Ting, Chao-Cheng; Chao, Chih-Hsuan; Tsai, Cheng Yu; Cheng, I.-Kai; Pan, Fu-Ming

2017-09-01

We sputter-deposited Pt nanoparticles with an average size ranging from 2.0 nm to 8.5 nm on the indium-tin oxide (ITO) glass substrate, and studied the effect of the size of Pt nanoparticles on electrocatalytic activity of the Pt/ITO electrode toward methanol oxidation reaction (MOR) in acidic solution. X-ray photoelectron spectroscopy (XPS) reveals an interfacial oxidized Pt layer present between Pt nanoparticles and the ITO substrate, which may modify the surface electronic structure of Pt nanoparticles and thus influences the electrocatalytic properties of the Pt catalyst toward MOR. According to electrochemical analyses, smaller Pt nanoparticles exhibit slower kinetics for CO electrooxidation and MOR. However, a smaller particle size enables better CO tolerance because the bifunctional mechanism is more effective on smaller Pt nanoparticles. The electrocatalytic activity decays rapidly for Pt nanoparticles with a size smaller than 3 nm and larger than 8 nm. The rapid activity decay is attributed to Pt dissolution for smaller nanoparticles and to CO poisoning for larger ones. Pt nanoparticles of 5-6 nm in size loaded on ITO demonstrate a greatly improved electrocatalytic activity and stability compared with those deposited on different substrates in our previous studies.

The Effectiveness of Psychoeducational Interventions Focused on Sexuality in Cancer.

PubMed

Kim, Jung-Hee; Yang, Younghee; Hwang, Eun-Suk

2015-01-01

Although sexual health is a common concern for oncology patients, no practical guidelines to sexual intervention exist, perhaps because of a lack of systematic reviews or meta-analyses. The objectives of this study were to determine the effect size for psychoeducational intervention focused on sexuality and to compare effect sizes according to intervention outcomes and characteristic. We explored quantitative evidence for the effects of sexual intervention for cancer patients or partners by using the electronic databases. Among them, we considered 15 eligible articles. The meta-analysis provided 133 effect sizes from 15 primary studies. The analysis revealed significant improvements after intervention, with a random-effects standardized mean difference of 0.75. Psychoeducational interventions focused on sexuality after cancer diagnosis were effective for compliance (2.40), cognitive aspect (1.29), and psychological aspect (0.83). Individual-based interventions (0.85) were more effective in improving outcomes than group approach and group combined with individual intervention. With regard to intervention providers, registered nurse only (2.22) and team approach including the registered nurse (2.38) had the highest effect size. Face-to-face intervention combined with telephone or the Internet (1.04) demonstrated a higher effect size than face-to-face (0.62) and telephone (0.58) independently. We conducted an analysis of data from various subgroups of preexisting studies, obtained an overall estimate of the effectiveness of the intervention, and compared its effectiveness across variables that affect intervention outcomes. These results provide empirical data for evidence-based practice and inform the development of useful intervention programs through a comprehensive review and meta-analysis of the results.

The Influence of Study-Level Inference Models and Study Set Size on Coordinate-Based fMRI Meta-Analyses

PubMed Central

Bossier, Han; Seurinck, Ruth; Kühn, Simone; Banaschewski, Tobias; Barker, Gareth J.; Bokde, Arun L. W.; Martinot, Jean-Luc; Lemaitre, Herve; Paus, Tomáš; Millenet, Sabina; Moerkerke, Beatrijs

2018-01-01

Given the increasing amount of neuroimaging studies, there is a growing need to summarize published results. Coordinate-based meta-analyses use the locations of statistically significant local maxima with possibly the associated effect sizes to aggregate studies. In this paper, we investigate the influence of key characteristics of a coordinate-based meta-analysis on (1) the balance between false and true positives and (2) the activation reliability of the outcome from a coordinate-based meta-analysis. More particularly, we consider the influence of the chosen group level model at the study level [fixed effects, ordinary least squares (OLS), or mixed effects models], the type of coordinate-based meta-analysis [Activation Likelihood Estimation (ALE) that only uses peak locations, fixed effects, and random effects meta-analysis that take into account both peak location and height] and the amount of studies included in the analysis (from 10 to 35). To do this, we apply a resampling scheme on a large dataset (N = 1,400) to create a test condition and compare this with an independent evaluation condition. The test condition corresponds to subsampling participants into studies and combine these using meta-analyses. The evaluation condition corresponds to a high-powered group analysis. We observe the best performance when using mixed effects models in individual studies combined with a random effects meta-analysis. Moreover the performance increases with the number of studies included in the meta-analysis. When peak height is not taken into consideration, we show that the popular ALE procedure is a good alternative in terms of the balance between type I and II errors. However, it requires more studies compared to other procedures in terms of activation reliability. Finally, we discuss the differences, interpretations, and limitations of our results. PMID:29403344

Simulation-based power calculation for designing interrupted time series analyses of health policy interventions.

PubMed

Zhang, Fang; Wagner, Anita K; Ross-Degnan, Dennis

2011-11-01

Interrupted time series is a strong quasi-experimental research design to evaluate the impacts of health policy interventions. Using simulation methods, we estimated the power requirements for interrupted time series studies under various scenarios. Simulations were conducted to estimate the power of segmented autoregressive (AR) error models when autocorrelation ranged from -0.9 to 0.9 and effect size was 0.5, 1.0, and 2.0, investigating balanced and unbalanced numbers of time periods before and after an intervention. Simple scenarios of autoregressive conditional heteroskedasticity (ARCH) models were also explored. For AR models, power increased when sample size or effect size increased, and tended to decrease when autocorrelation increased. Compared with a balanced number of study periods before and after an intervention, designs with unbalanced numbers of periods had less power, although that was not the case for ARCH models. The power to detect effect size 1.0 appeared to be reasonable for many practical applications with a moderate or large number of time points in the study equally divided around the intervention. Investigators should be cautious when the expected effect size is small or the number of time points is small. We recommend conducting various simulations before investigation. Copyright © 2011 Elsevier Inc. All rights reserved.

The extent and consequences of p-hacking in science.

PubMed

Head, Megan L; Holman, Luke; Lanfear, Rob; Kahn, Andrew T; Jennions, Michael D

2015-03-01

A focus on novel, confirmatory, and statistically significant results leads to substantial bias in the scientific literature. One type of bias, known as "p-hacking," occurs when researchers collect or select data or statistical analyses until nonsignificant results become significant. Here, we use text-mining to demonstrate that p-hacking is widespread throughout science. We then illustrate how one can test for p-hacking when performing a meta-analysis and show that, while p-hacking is probably common, its effect seems to be weak relative to the real effect sizes being measured. This result suggests that p-hacking probably does not drastically alter scientific consensuses drawn from meta-analyses.

Ethnic and gender differences in ideal body size and related attitudes among Asians, Native Hawaiians, and Whites.

PubMed

Townsend, Claire; Takishima-Lacasa, Julie Y; Latner, Janet D; Grandinetti, Andrew; Keawe'aimoku Kaholokula, Joseph

2014-08-01

Often overlooked explanations for the varied obesity rates across ethno-cultural groups include differences in attitudes toward excess weight, with certain populations assumed to have larger ideal body sizes (IBS). Past studies found ethnic and gender difference in IBS across and within different groups. This study examined the effects of ethnicity and gender, and their interaction, in accounting for differences in IBS and attitudes toward those ideals. Multiple regression analyses were used to better understand the effects of ethnicity and gender in accounting for differences in perceived IBS according to ethnic-specific and Western ideals and attitudes in 1,124 people of Native Hawaiian, Filipino, Japanese, and White ancestry. The analyses controlled for socio-demographics, body mass index, health-related behaviors, and psychosocial variables. The results indicated that Native Hawaiians selected larger ethnic IBS, Filipinos selected smaller ethnic IBS, and Native Hawaiians selected slightly smaller Western IBS than other ethnic groups. Overall, males selected larger IBS compared to females. Interaction analyses indicated that the relationship between ethnic IBS and attitude toward that IBS varied as a function of ethnicity, such that Native Hawaiians who selected a larger ethnic IBS held less favorable attitudes toward that IBS. The discrepancy between Native Hawaiians' selection of larger ethnic IBS as ideal and their less positive attitude toward that selection warrants more investigation. However, it does suggest that Native Hawaiians, on a personal level, do not prefer larger body sizes, which contradicts their perceptions of social norms. These findings have important implications for obesity interventions among Native Hawaiians.

Ethnic and Gender Differences in Ideal Body Size and Related Attitudes among Asians, Native Hawaiians, and Whites

PubMed Central

Takishima-Lacasa, Julie Y; Latner, Janet D; Grandinetti, Andrew; Keawe‘aimoku Kaholokula, Joseph

2014-01-01

Often overlooked explanations for the varied obesity rates across ethno-cultural groups include differences in attitudes toward excess weight, with certain populations assumed to have larger ideal body sizes (IBS). Past studies found ethnic and gender difference in IBS across and within different groups. This study examined the effects of ethnicity and gender, and their interaction, in accounting for differences in IBS and attitudes toward those ideals. Multiple regression analyses were used to better understand the effects of ethnicity and gender in accounting for differences in perceived IBS according to ethnic-specific and Western ideals and attitudes in 1,124 people of Native Hawaiian, Filipino, Japanese, and White ancestry. The analyses controlled for socio-demographics, body mass index, health-related behaviors, and psychosocial variables. The results indicated that Native Hawaiians selected larger ethnic IBS, Filipinos selected smaller ethnic IBS, and Native Hawaiians selected slightly smaller Western IBS than other ethnic groups. Overall, males selected larger IBS compared to females. Interaction analyses indicated that the relationship between ethnic IBS and attitude toward that IBS varied as a function of ethnicity, such that Native Hawaiians who selected a larger ethnic IBS held less favorable attitudes toward that IBS. The discrepancy between Native Hawaiians' selection of larger ethnic IBS as ideal and their less positive attitude toward that selection warrants more investigation. However, it does suggest that Native Hawaiians, on a personal level, do not prefer larger body sizes, which contradicts their perceptions of social norms. These findings have important implications for obesity interventions among Native Hawaiians. PMID:25157324

Effectiveness of internet-based affect induction procedures: A systematic review and meta-analysis.

PubMed

Ferrer, Rebecca A; Grenen, Emily G; Taber, Jennifer M

2015-12-01

Procedures used to induce affect in a laboratory are effective and well-validated. Given recent methodological and technological advances in Internet research, it is important to determine whether affect can be effectively induced using Internet methodology. We conducted a meta-analysis and systematic review of prior research that has used Internet-based affect induction procedures, and examined potential moderators of the effectiveness of affect induction procedures. Twenty-six studies were included in final analyses, with 89 independent effect sizes. Affect induction procedures effectively induced general positive affect, general negative affect, fear, disgust, anger, sadness, and guilt, but did not significantly induce happiness. Contamination of other nontarget affect did not appear to be a major concern. Video inductions resulted in greater effect sizes. Overall, results indicate that affect can be effectively induced in Internet studies, suggesting an important venue for the acceleration of affective science. (PsycINFO Database Record (c) 2015 APA, all rights reserved).

Founder representation and effective population size in old versus young breeds-genetic diversity of Finnish and Nordic Spitz.

PubMed

Kumpulainen, M; Anderson, H; Svevar, T; Kangasvuo, I; Donner, J; Pohjoismäki, J

2017-10-01

Finnish Spitz is 130-year-old breed and has been highly popular in Finland throughout its history. Nordic Spitz is very similar to Finnish Spitz by origin and use, but is a relatively recent breed with much smaller population size. To see how breed age and breeding history have influenced the current population, we performed comprehensive population genetic analysis using pedigree data of 28,119 Finnish and 9,009 Nordic Spitzes combined with genomewide single nucleotide polymorphism (SNP) data from 135 Finnish and 110 Nordic Spitzes. We found that the Finnish Spitz has undergone repeated male bottlenecks resulting in dramatic loss of genetic diversity, reflected by 20 effective founders (f a ) and mean heterozygosity (Hz) of 0.313. The realized effective population size in the breed based on pedigree analysis (N¯ec) is 168, whereas the genetic effective population size (N eg ) computed the decay of linkage disequilibrium (r 2 ) is only 57 individuals. Nordic Spitz, although once been near extinction, has not been exposed to similar repeated bottlenecks than Finnish Spitz and had f a of 27 individuals. However, due to the smaller total population size, the breed has also smaller effective population size than Finnish Spitz (N¯ec = 98 and N eg  = 49). Interestingly, the r 2 data show that the effective population size has contracted dramatically since the establishment of the breed, emphasizing the role of breed standards as constrains for the breeding population. Despite the small population size, Nordic Spitz still maintains SNP heterozygosity levels similar to mixed breed dogs (mean Hz = 0.409). Our study demonstrates that although pedigree analyses cannot provide estimates of the present diversity within a breed, the effective population sizes inferred from them correlate with the genotyping results. The genetic relationships of the northern Spitz breeds and the benefits of the open breed registry are discussed. © 2017 Blackwell Verlag GmbH.

Ataxia Telangiectasia–Mutated Gene Polymorphisms and Acute Normal Tissue Injuries in Cancer Patients After Radiation Therapy: A Systematic Review and Meta-analysis

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

Dong, Lihua; Cui, Jingkun; Tang, Fengjiao

Purpose: Studies of the association between ataxia telangiectasia–mutated (ATM) gene polymorphisms and acute radiation injuries are often small in sample size, and the results are inconsistent. We conducted the first meta-analysis to provide a systematic review of published findings. Methods and Materials: Publications were identified by searching PubMed up to April 25, 2014. Primary meta-analysis was performed for all acute radiation injuries, and subgroup meta-analyses were based on clinical endpoint. The influence of sample size and radiation injury incidence on genetic effects was estimated in sensitivity analyses. Power calculations were also conducted. Results: The meta-analysis was conducted on the ATMmore » polymorphism rs1801516, including 5 studies with 1588 participants. For all studies, the cut-off for differentiating cases from controls was grade 2 acute radiation injuries. The primary meta-analysis showed a significant association with overall acute radiation injuries (allelic model: odds ratio = 1.33, 95% confidence interval: 1.04-1.71). Subgroup analyses detected an association between the rs1801516 polymorphism and a significant increase in urinary and lower gastrointestinal injuries and an increase in skin injury that was not statistically significant. There was no between-study heterogeneity in any meta-analyses. In the sensitivity analyses, small studies did not show larger effects than large studies. In addition, studies with high incidence of acute radiation injuries showed larger effects than studies with low incidence. Power calculations revealed that the statistical power of the primary meta-analysis was borderline, whereas there was adequate power for the subgroup analysis of studies with high incidence of acute radiation injuries. Conclusions: Our meta-analysis showed a consistency of the results from the overall and subgroup analyses. We also showed that the genetic effect of the rs1801516 polymorphism on acute radiation injuries was dependent on the incidence of the injury. These support the evidence of an association between the rs1801516 polymorphism and acute radiation injuries, encouraging further research of this topic.« less

Interpretation of correlations in clinical research.

PubMed

Hung, Man; Bounsanga, Jerry; Voss, Maren Wright

2017-11-01

Critically analyzing research is a key skill in evidence-based practice and requires knowledge of research methods, results interpretation, and applications, all of which rely on a foundation based in statistics. Evidence-based practice makes high demands on trained medical professionals to interpret an ever-expanding array of research evidence. As clinical training emphasizes medical care rather than statistics, it is useful to review the basics of statistical methods and what they mean for interpreting clinical studies. We reviewed the basic concepts of correlational associations, violations of normality, unobserved variable bias, sample size, and alpha inflation. The foundations of causal inference were discussed and sound statistical analyses were examined. We discuss four ways in which correlational analysis is misused, including causal inference overreach, over-reliance on significance, alpha inflation, and sample size bias. Recent published studies in the medical field provide evidence of causal assertion overreach drawn from correlational findings. The findings present a primer on the assumptions and nature of correlational methods of analysis and urge clinicians to exercise appropriate caution as they critically analyze the evidence before them and evaluate evidence that supports practice. Critically analyzing new evidence requires statistical knowledge in addition to clinical knowledge. Studies can overstate relationships, expressing causal assertions when only correlational evidence is available. Failure to account for the effect of sample size in the analyses tends to overstate the importance of predictive variables. It is important not to overemphasize the statistical significance without consideration of effect size and whether differences could be considered clinically meaningful.

Mixed-grass prairie passerines exhibit weak and variable responses to patch size

USGS Publications Warehouse

Davis, S.K.; Brigham, R.M.; Shaffer, T.L.; James, P.C.

2006-01-01

Much of our current understanding of the demographic effects of habitat fragmentation on bird populations is derived from studies of passerines in forests and tallgrass prairie surrounded by woody vegetation. We quantified grassland bird density, nest survival, and productivity in 41 native mixed-grass prairie pastures during 1997-2000 in southern Saskatchewan, Canada. Pastures ranged in size from 18 ha to 11,600 ha and were typically surrounded by agriculture (i.e., ranching and annual cropping). Grassland passerines did not respond strongly or uniformly to patch size. Sprague's Pipit (Anthus spragueii) was the only species whose density increased with pasture size. Patch size had minimal influence on nest survival of Sprague's Pipit or Clay-colored Sparrow (Spizella pallida); whereas nest survival increased with patch size for Savannah Sparrow (Passerculus sandwichensis) and declined for Baird's Sparrow (Ammodramus bairdii), Chestnut-collared Longspur (Calcarius ornatus), and Western Meadowlark (Sturnella neglecta). Time-specific factors (i.e., nest age, date, and year) were more important predictors of nest survival than patch size. Exploratory analyses indicated that effects of edge distance, pasture shape, or landscape on nest survival were just as likely as patch-size effects. However, effects of edge on Chestnut-collared Longspurs may be governed by landscape-level factors, because nest survival decreased with distance to edge in landscapes with increased amounts of cropland. Our results indicate that mixed-grass prairie parcels ≥18 ha play a role in the conservation of several grassland passerine species currently in decline, but the conservation of Sprague's Pipit likely depends on maintaining larger tracts of native prairie.

Trial Sequential Analysis in systematic reviews with meta-analysis.

PubMed

Wetterslev, Jørn; Jakobsen, Janus Christian; Gluud, Christian

2017-03-06

Most meta-analyses in systematic reviews, including Cochrane ones, do not have sufficient statistical power to detect or refute even large intervention effects. This is why a meta-analysis ought to be regarded as an interim analysis on its way towards a required information size. The results of the meta-analyses should relate the total number of randomised participants to the estimated required meta-analytic information size accounting for statistical diversity. When the number of participants and the corresponding number of trials in a meta-analysis are insufficient, the use of the traditional 95% confidence interval or the 5% statistical significance threshold will lead to too many false positive conclusions (type I errors) and too many false negative conclusions (type II errors). We developed a methodology for interpreting meta-analysis results, using generally accepted, valid evidence on how to adjust thresholds for significance in randomised clinical trials when the required sample size has not been reached. The Lan-DeMets trial sequential monitoring boundaries in Trial Sequential Analysis offer adjusted confidence intervals and restricted thresholds for statistical significance when the diversity-adjusted required information size and the corresponding number of required trials for the meta-analysis have not been reached. Trial Sequential Analysis provides a frequentistic approach to control both type I and type II errors. We define the required information size and the corresponding number of required trials in a meta-analysis and the diversity (D 2 ) measure of heterogeneity. We explain the reasons for using Trial Sequential Analysis of meta-analysis when the actual information size fails to reach the required information size. We present examples drawn from traditional meta-analyses using unadjusted naïve 95% confidence intervals and 5% thresholds for statistical significance. Spurious conclusions in systematic reviews with traditional meta-analyses can be reduced using Trial Sequential Analysis. Several empirical studies have demonstrated that the Trial Sequential Analysis provides better control of type I errors and of type II errors than the traditional naïve meta-analysis. Trial Sequential Analysis represents analysis of meta-analytic data, with transparent assumptions, and better control of type I and type II errors than the traditional meta-analysis using naïve unadjusted confidence intervals.

Determining Sample Sizes for Precise Contrast Analysis with Heterogeneous Variances

ERIC Educational Resources Information Center

Jan, Show-Li; Shieh, Gwowen

2014-01-01

The analysis of variance (ANOVA) is one of the most frequently used statistical analyses in practical applications. Accordingly, the single and multiple comparison procedures are frequently applied to assess the differences among mean effects. However, the underlying assumption of homogeneous variances may not always be tenable. This study…

A Meta-Analysis: The Relationship Between Parental Involvement and Latino Student Outcomes

ERIC Educational Resources Information Center

Jeynes, William H.

2017-01-01

This meta-analysis of 28 studies examines the relationship between parental involvement and the academic achievement and school behavior of Latino pre-kindergarten-college-age children. Analyses determined the effect sizes for parental involvement overall and specific categories of involvement. Results indicate a significant relationship between…

The Effectiveness of Self-Regulated Learning Scaffolds on Academic Performance in Computer-Based Learning Environments: A Meta-Analysis

ERIC Educational Resources Information Center

Zheng, Lanqin

2016-01-01

This meta-analysis examined research on the effects of self-regulated learning scaffolds on academic performance in computer-based learning environments from 2004 to 2015. A total of 29 articles met inclusion criteria and were included in the final analysis with a total sample size of 2,648 students. Moderator analyses were performed using a…

Maternal Work Early in the Lives of Children and Its Distal Associations with Achievement and Behavior Problems: A Meta-Analysis

ERIC Educational Resources Information Center

Lucas-Thompson, Rachel G.; Goldberg, Wendy A.; Prause, JoAnn

2010-01-01

This meta-analysis of 69 studies (1,483 effect sizes) used random effects models to examine maternal employment during infancy/early childhood in relation to 2 major domains of child functioning: achievement and behavior problems. Analyses of studies that spanned 5 decades indicated that, with a few exceptions, early employment was not…

What Makes a Word Easy to Acquire? The Effects of Word Class, Frequency, Imageability and Phonological Neighbourhood Density on Lexical Development

ERIC Educational Resources Information Center

Hansen, Pernille

2017-01-01

This article analyses how a set of psycholinguistic factors may account for children's lexical development. Age of acquisition is compared to a measure of lexical development based on vocabulary size rather than age, and robust regression models are used to assess the individual and joint effects of word class, frequency, imageability and…

A Meta-Analytic Review of Stand-Alone Interventions to Improve Body Image

PubMed Central

Alleva, Jessica M.; Sheeran, Paschal; Webb, Thomas L.; Martijn, Carolien; Miles, Eleanor

2015-01-01

Objective Numerous stand-alone interventions to improve body image have been developed. The present review used meta-analysis to estimate the effectiveness of such interventions, and to identify the specific change techniques that lead to improvement in body image. Methods The inclusion criteria were that (a) the intervention was stand-alone (i.e., solely focused on improving body image), (b) a control group was used, (c) participants were randomly assigned to conditions, and (d) at least one pretest and one posttest measure of body image was taken. Effect sizes were meta-analysed and moderator analyses were conducted. A taxonomy of 48 change techniques used in interventions targeted at body image was developed; all interventions were coded using this taxonomy. Results The literature search identified 62 tests of interventions (N = 3,846). Interventions produced a small-to-medium improvement in body image (d + = 0.38), a small-to-medium reduction in beauty ideal internalisation (d + = -0.37), and a large reduction in social comparison tendencies (d + = -0.72). However, the effect size for body image was inflated by bias both within and across studies, and was reliable but of small magnitude once corrections for bias were applied. Effect sizes for the other outcomes were no longer reliable once corrections for bias were applied. Several features of the sample, intervention, and methodology moderated intervention effects. Twelve change techniques were associated with improvements in body image, and three techniques were contra-indicated. Conclusions The findings show that interventions engender only small improvements in body image, and underline the need for large-scale, high-quality trials in this area. The review identifies effective techniques that could be deployed in future interventions. PMID:26418470

Risky Sexual Behavior and Substance Use among Adolescents: A Meta-analysis

PubMed Central

Ritchwood, Tiarney D.; Ford, Haley; DeCoster, Jamie; Sutton, Marnie; Lochman, John E.

2015-01-01

This study presents the results of a meta-analysis of the association between substance use and risky sexual behavior among adolescents. 87 studies fit the inclusion criteria, containing a total of 104 independent effect sizes that incorporated more than 120,000 participants. The overall effect size for the relationship between substance use and risky sexual behavior was in the small to moderate range (r = .22, CI = .18, .26). Further analyses indicated that the effect sizes did not substantially vary across the type of substance use, but did substantially vary across the type of risky sexual behavior being assessed. Specifically, mean effect sizes were smallest for studies examining unprotected sex (r = .15, CI = .10, .20), followed by studies examining number of sexual partners (r = .25, CI = .21, .30), those examining composite measures of risky sexual behavior (r = .38, CI = .27, .48), and those examining sex with an intravenous drug user (r = .53, CI = .45, .60). Furthermore, our results revealed that the relationship between drug use and risky sexual behavior is moderated by several variables, including sex, ethnicity, sexuality, age, sample type, and level of measurement. Implications and future directions are discussed. PMID:25825550

Influences of population size and density on birthplace effects.

PubMed

Hancock, David J; Coutinho, Patrícia; Côté, Jean; Mesquita, Isabel

2018-01-01

Contextual influences on talent development (e.g., birthplace effects) have become a topic of interest for sport scientists. Birthplace effects occur when being born in a certain city size leads to participation or performance advantages, typically for those born in smaller or mid-sized cities. The purpose of this study was to investigate birthplace effects in Portuguese volleyball players by analysing city size, as well as population density - an important but infrequently used variable. Participants included 4062 volleyball players (M age  = 33), 53.2% of whom were men. Using Portuguese national census data from 1981, we compared participants (within each sex) across five population categories. In addition, we used ANOVAs to study expertise and population density. Results indicated that men and women athletes born in districts of 200,000-399,999 were 2.4 times more likely to attain elite volleyball status, while all other districts decreased the odds of expert development. For men, being born in high-density areas resulted in less chance of achieving expertise, whereas there were no differences for women. The results suggest that athletes' infrastructure and social structure play an important role in talent development, and that these structures are influenced by total population and population density, respectively.

Exercise interventions for the improvement of falls-related outcomes among older adults with diabetes mellitus: A systematic review and meta-analyses.

PubMed

Chapman, Anna; Meyer, Claudia; Renehan, Emma; Hill, Keith D; Browning, Colette J

2017-03-01

Falls as a complication of diabetes mellitus (DM) can have a major impact on the health of older adults. Previous reviews have demonstrated that certain exercise interventions are effective at reducing falls in older people; however, no studies have quantified the effectiveness of exercise interventions on falls-related outcomes among older adults with DM. A systematic search for all years to September 2015 identified available literature. Eligibility criteria included: appropriate exercise intervention/s; assessed falls-related outcomes; older adults with DM. Effect sizes were pooled using a random effects model. Positive effect sizes favoured the intervention. Ten RCTs were eligible for the meta-analyses. Exercise interventions were more effective than the control condition for static balance (0.53, 95% CI: 0.13 to 0.93), lower-limb strength (0.63, 95% CI: 0.09 to 1.18), and gait (0.59, 95% CI: 0.22 to 0.96). No RCTs assessed falls-risk; one RCT reported 12month falls-rate, with no differential treatment effect observed. Exercise interventions can improve certain falls-related outcomes among older adults with DM. Substantial heterogeneity and limited numbers of studies should be considered when interpreting results. Among older adults, where DM burden is increasing, exercise interventions may provide promising approaches to assist the improvement of falls-related outcomes. Copyright © 2016 Elsevier Inc. All rights reserved.

Ostwald ripening of clays and metamorphic minerals

USGS Publications Warehouse

Eberl, D.D.; Srodon, J.; Kralik, M.; Taylor, B.E.; Peterman, Z.E.

1990-01-01

Analyses of particle size distributions indicate that clay minerals and other diagenetic and metamorphic minerals commonly undergo recrystallization by Ostwald ripening. The shapes of their particle size distributions can yield the rate law for this process. One consequence of Ostwald ripening is that a record of the recrystallization process is preserved in the various particle sizes. Therefore, one can determine the detailed geologic history of clays and other recrystallized minerals by separating, from a single sample, the various particle sizes for independent chemical, structural, and isotopic analyses.

Anorexia nervosa and bulimia nervosa: A meta-analysis of executive functioning.

PubMed

Hirst, Rayna B; Beard, Charlotte L; Colby, Katrina A; Quittner, Zoe; Mills, Brent M; Lavender, Jason M

2017-12-01

Research investigating the link between eating disorder (ED) diagnosis and executive dysfunction has had conflicting results, yet no meta-analyses have examined the overall association of ED pathology with executive functioning (EF). Effect sizes were extracted from 32 studies comparing ED groups (27 of anorexia nervosa, 9 of bulimia nervosa) with controls to determine the grand mean effect on EF. Analyses included effects for individual EF measures, as well as an age-based subgroup analysis. There was a medium effect of ED diagnosis on executive functioning, with bulimia nervosa demonstrating a larger effect (Hedges's g=-0.70) than anorexia nervosa (g=-0.41). Within anorexia nervosa studies, subgroup analyses were conducted for age and diagnostic subtype. The effect of anorexia nervosa on EF was largest in adults; however, subgroup differences for age were not significant. Anorexia and bulimia nervosa are associated with EF deficits, which are particularly notable for individuals with bulimia nervosa. The present analysis includes recommendations for future studies regarding study design and EF measurement. Copyright © 2017 Elsevier Ltd. All rights reserved.

The effect of food portion sizes on the obesity prevention using system dynamics modelling

NASA Astrophysics Data System (ADS)

Abidin, Norhaslinda Zainal; Zulkepli, Jafri Hj; Zaibidi, Nerda Zura

2014-09-01

The rise in income and population growth have increased the demand for food and induced changes in food habits, food purchasing and consumption patterns in Malaysia. With this transition, one of the plausible causes of weight gain and obesity is the frequent consumption of outside food which is synonymous with bigger portion size. Therefore, the aim of this paper is to develop a system dynamics model to analyse the effect of reducing food portion size on weight and obesity prevention. This study combines the different strands of knowledge comprise of nutrition, physical activity and body metabolism. These elements are synthesized into a system dynamics model called SIMULObese. Findings from this study suggested that changes in eating behavior should not emphasize only on limiting the food portion size consumption. The efforts should also consider other eating events such as controlling the meal frequency and limiting intake of high-calorie food in developing guidelines to prevent obesity.

The Efficacy of Mindfulness-Based Interventions in Primary Care: A Meta-Analytic Review.

PubMed

Demarzo, Marcelo M P; Montero-Marin, Jesús; Cuijpers, Pim; Zabaleta-del-Olmo, Edurne; Mahtani, Kamal R; Vellinga, Akke; Vicens, Caterina; López-del-Hoyo, Yolanda; García-Campayo, Javier

2015-11-01

Positive effects have been reported after mindfulness-based interventions (MBIs) in diverse clinical and nonclinical populations. Primary care is a key health care setting for addressing common chronic conditions, and an effective MBI designed for this setting could benefit countless people worldwide. Meta-analyses of MBIs have become popular, but little is known about their efficacy in primary care. Our aim was to investigate the application and efficacy of MBIs that address primary care patients. We performed a meta-analytic review of randomized controlled trials addressing the effect of MBIs in adult patients recruited from primary care settings. The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) and Cochrane guidelines were followed. Effect sizes were calculated with the Hedges g in random effects models. The meta-analyses were based on 6 trials having a total of 553 patients. The overall effect size of MBI compared with a control condition for improving general health was moderate (g = 0.48; P = .002), with moderate heterogeneity (I(2) = 59; P <.05). We found no indication of publication bias in the overall estimates. MBIs were efficacious for improving mental health (g = 0.56; P = .007), with a high heterogeneity (I(2) = 78; P <.01), and for improving quality of life (g = 0.29; P = .002), with a low heterogeneity (I(2) = 0; P >.05). Although the number of randomized controlled trials applying MBIs in primary care is still limited, our results suggest that these interventions are promising for the mental health and quality of life of primary care patients. We discuss innovative approaches for implementing MBIs, such as complex intervention and stepped care. © 2015 Annals of Family Medicine, Inc.

The Efficacy of Mindfulness-Based Interventions in Primary Care: A Meta-Analytic Review

PubMed Central

Demarzo, Marcelo M.P.; Montero-Marin, Jesús; Cuijpers, Pim; Zabaleta-del-Olmo, Edurne; Mahtani, Kamal R.; Vellinga, Akke; Vicens, Caterina; López-del-Hoyo, Yolanda; García-Campayo, Javier

2015-01-01

PURPOSE Positive effects have been reported after mindfulness-based interventions (MBIs) in diverse clinical and nonclinical populations. Primary care is a key health care setting for addressing common chronic conditions, and an effective MBI designed for this setting could benefit countless people worldwide. Meta-analyses of MBIs have become popular, but little is known about their efficacy in primary care. Our aim was to investigate the application and efficacy of MBIs that address primary care patients. METHODS We performed a meta-analytic review of randomized controlled trials addressing the effect of MBIs in adult patients recruited from primary care settings. The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) and Cochrane guidelines were followed. Effect sizes were calculated with the Hedges g in random effects models. RESULTS The meta-analyses were based on 6 trials having a total of 553 patients. The overall effect size of MBI compared with a control condition for improving general health was moderate (g = 0.48; P = .002), with moderate heterogeneity (I2 = 59; P <.05). We found no indication of publication bias in the overall estimates. MBIs were efficacious for improving mental health (g = 0.56; P = .007), with a high heterogeneity (I2 = 78; P <.01), and for improving quality of life (g = 0.29; P = .002), with a low heterogeneity (I2 = 0; P >.05). CONCLUSIONS Although the number of randomized controlled trials applying MBIs in primary care is still limited, our results suggest that these interventions are promising for the mental health and quality of life of primary care patients. We discuss innovative approaches for implementing MBIs, such as complex intervention and stepped care. PMID:26553897

Cognitive Behavior Therapy for Schizophrenia: Effect Sizes, Clinical Models, and Methodological Rigor

PubMed Central

Wykes, Til; Steel, Craig; Everitt, Brian; Tarrier, Nicholas

2008-01-01

Background: Guidance in the United States and United Kingdom has included cognitive behavior therapy for psychosis (CBTp) as a preferred therapy. But recent advances have widened the CBTp targets to other symptoms and have different methods of provision, eg, in groups. Aim: To explore the effect sizes of current CBTp trials including targeted and nontargeted symptoms, modes of action, and effect of methodological rigor. Method: Thirty-four CBTp trials with data in the public domain were used as source data for a meta-analysis and investigation of the effects of trial methodology using the Clinical Trial Assessment Measure (CTAM). Results: There were overall beneficial effects for the target symptom (33 studies; effect size = 0.400 [95% confidence interval {CI} = 0.252, 0.548]) as well as significant effects for positive symptoms (32 studies), negative symptoms (23 studies), functioning (15 studies), mood (13 studies), and social anxiety (2 studies) with effects ranging from 0.35 to 0.44. However, there was no effect on hopelessness. Improvements in one domain were correlated with improvements in others. Trials in which raters were aware of group allocation had an inflated effect size of approximately 50%–100%. But rigorous CBTp studies showed benefit (estimated effect size = 0.223; 95% CI = 0.017, 0.428) although the lower end of the CI should be noted. Secondary outcomes (eg, negative symptoms) were also affected such that in the group of methodologically adequate studies the effect sizes were not significant. Conclusions: As in other meta-analyses, CBTp had beneficial effect on positive symptoms. However, psychological treatment trials that make no attempt to mask the group allocation are likely to have inflated effect sizes. Evidence considered for psychological treatment guidance should take into account specific methodological detail. PMID:17962231

The Effect of Hypnosis on Anxiety in Patients With Cancer: A Meta-Analysis.

PubMed

Chen, Pei-Ying; Liu, Ying-Mei; Chen, Mei-Ling

2017-06-01

Anxiety is a common form of psychological distress in patients with cancer. One recognized nonpharmacological intervention to reduce anxiety for various populations is hypnotherapy or hypnosis. However, its effect in reducing anxiety in cancer patients has not been systematically evaluated. This meta-analysis was designed to synthesize the immediate and sustained effects of hypnosis on anxiety of cancer patients and to identify moderators for these hypnosis effects. Qualified studies including randomized controlled trials (RCT) and pre-post design studies were identified by searching seven electronic databases: Scopus, Medline Ovidsp, PubMed, PsycInfo-Ovid, Academic Search Premier, CINAHL Plus with FT-EBSCO, and SDOL. Effect size (Hedges' g) was computed for each study. Random-effect modeling was used to combine effect sizes across studies. All statistical analyses were conducted with Comprehensive Meta-Analysis, version 2 (Biostat, Inc., Englewood, NJ, USA). Our meta-analysis of 20 studies found that hypnosis had a significant immediate effect on anxiety in cancer patients (Hedges' g: 0.70-1.41, p < .01) and the effect was sustained (Hedges' g: 0.61-2.77, p < .01). The adjusted mean effect size (determined by Duvan and Tweedie's trim-and-fill method) was 0.46. RCTs had a significantly higher effect size than non-RCT studies. Higher mean effect sizes were also found with pediatric study samples, hematological malignancy, studies on procedure-related stressors, and with mixed-gender samples. Hypnosis delivered by a therapist was significantly more effective than self-hypnosis. Hypnosis can reduce anxiety of cancer patients, especially for pediatric cancer patients who experience procedure-related stress. We recommend therapist-delivered hypnosis should be preferred until more effective self-hypnosis strategies are developed. © 2017 Sigma Theta Tau International.

Quantifying invertebrate resistance to floods: a global-scale meta-analysis.

PubMed

McMullen, Laura E; Lytle, David A

2012-12-01

Floods are a key component of the ecology and management of riverine ecosystems around the globe, but it is not clear whether floods have predictable effects on organisms that can allow us to generalize across regions and continents. To address this, we conducted a global-scale meta-analysis to investigate effects of natural and managed floods on invertebrate resistance, the ability of invertebrates to survive flood events. We considered 994 studies for inclusion in the analysis, and after evaluation based on a priori criteria, narrowed our analysis to 41 studies spanning six of the seven continents. We used the natural-log-ratio of invertebrate abundance before and within 10 days after flood events because this measure of effect size can be directly converted to estimates of percent survival. We conducted categorical and continuous analyses that examined the contribution of environmental and study design variables to effect size heterogeneity, and examined differences in effect size among taxonomic groups. We found that invertebrate abundance was lowered by at least one-half after flood events. While natural vs. managed floods were similar in their effect, effect size differed among habitat and substrate types, with pools, sand, and boulders experiencing the strongest effect. Although sample sizes were not sufficient to examine all taxonomic groups, floods had a significant, negative effect on densities of Coleoptera, Eumalacostraca, Annelida, Ephemeroptera, Diptera, Plecoptera, and Trichoptera. Results from this study provide guidance for river flow regime prescriptions that will be applicable across continents and climate types, as well as baseline expectations for future empirical studies of freshwater disturbance.

Gestational age and newborn size according to parental social mobility: an intergenerational cohort study.

PubMed

Gigante, Denise P; Horta, Bernardo L; Matijasevich, Alicia; Mola, Christian Loret de; Barros, Aluisio J D; Santos, Ina S; Barros, Fernando C; Victora, Cesar G

2015-10-01

We examined the associations between socioeconomic trajectories from birth to adulthood and gestational age and birth size in the next generation, using linked data from two population-based birth cohorts carried out in a Brazilian city. By comparing socioeconomic trajectories of mothers and fathers, we attempted to identify-specific effects of maternal and paternal socioeconomic trajectory on offspring birth weight, birth length, head circumference and gestational age at birth. 2 population-based birth cohort studies were carried out in 1982 and 2004 in Pelotas (Brazil); 156 mothers and 110 fathers from the earlier cohort had children in 2004. Gestational age and birth length, weight and head circumference were measured. Analyses were carried out separately for mothers and fathers. Mediation analyses assessed the role of birth weight and adult body mass index (BMI). Among mothers, but not for fathers, childhood poverty was strongly associated with smaller size in the next generation (about 400 g in weight and 1.5 cm in height) and shorter gestations (about 2 weeks). Adult poverty did not play a role. For mothers, the associations with gestational age, birth length and weight-but not with head circumference-persisted after adjusting for maternal birth weight and for the height and weight of the grandmother. Maternal birth weight did not mediate the observed associations, but high maternal BMI in adulthood was partly responsible for the association with gestational age. Strong effects of early poverty on gestational age and birth size in the next generation were observed among mothers, but not among fathers. These findings suggest a specific maternal effect of socioeconomic trajectory, and in particular of early poverty on offspring size and duration of pregnancy. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Insecure Adult Attachment and Child Maltreatment: A Meta-Analysis.

PubMed

Lo, Camilla K M; Chan, Ko Ling; Ip, Patrick

2017-01-01

Extant evidence has shown that insecure adult attachment is related to dysfunctional parenting styles that heighten parents' risk of child maltreatment. However, there is a lack of studies appraising the evidence for the association between insecure adult attachment and child maltreatment. This meta-analytic study examined the relationship between parents' adult attachment and child maltreatment perpetration/child abuse potential. Studies examining the relationship between parents' adult attachment and child maltreatment/child abuse potential published before February 2017 were identified through a systematic search of online databases. In total, 16 studies ( N = 1,830) were selected. Meta-analysis based on random-effects models shows a significant positive association between insecure attachment and child maltreatment (pooled effect size: odds ratio [ OR] = 2.93, p = .000). Subgroup analyses show insecure attachment was more strongly associated with failure to thrive ( OR = 8.04, p = .000) and filicide ( OR = 5.00, p < .05). Medium effect sizes were found for subgroup analyses on insecure romantic attachment ( OR = 3.76, p = .000), general attachment ( OR = 3.38, p = .000), attachment to own child ( OR = 3.13, p = .001), and to own parents ( OR = 2.63, p = .000) in relation to child maltreatment.

Are leader stereotypes masculine? A meta-analysis of three research paradigms.

PubMed

Koenig, Anne M; Eagly, Alice H; Mitchell, Abigail A; Ristikari, Tiina

2011-07-01

This meta-analysis examined the extent to which stereotypes of leaders are culturally masculine. The primary studies fit into 1 of 3 paradigms: (a) In Schein's (1973) think manager-think male paradigm, 40 studies with 51 effect sizes compared the similarity of male and leader stereotypes and the similarity of female and leader stereotypes; (b) in Powell and Butterfield's (1979) agency-communion paradigm, 22 studies with 47 effect sizes compared stereotypes of leaders' agency and communion; and (c) in Shinar's (1975) masculinity-femininity paradigm, 7 studies with 101 effect sizes represented stereotypes of leadership-related occupations on a single masculinity-femininity dimension. Analyses implemented appropriate random and mixed effects models. All 3 paradigms demonstrated overall masculinity of leader stereotypes: (a) In the think manager-think male paradigm, intraclass correlation = .25 for the women-leaders similarity and intraclass correlation = .62 for the men-leaders similarity; (b) in the agency-communion paradigm, g = 1.55, indicating greater agency than communion; and (c) in the masculinity-femininity paradigm, g = 0.92, indicating greater masculinity than the androgynous scale midpoint. Subgroup and meta-regression analyses indicated that this masculine construal of leadership has decreased over time and was greater for male than female research participants. In addition, stereotypes portrayed leaders as less masculine in educational organizations than in other domains and in moderate- than in high-status leader roles. This article considers the relation of these findings to Eagly and Karau's (2002) role congruity theory, which proposed contextual influences on the incongruity between stereotypes of women and leaders. The implications for prejudice against women leaders are also considered.

Outcomes associated with virtual reality in psychological interventions: where are we now?

PubMed

Turner, Wesley A; Casey, Leanne M

2014-12-01

The impending commercial release of affordable VR systems is likely to accelerate both the opportunity and demand for VR applications that specifically target psychological conditions. The aim of this study was to conduct a meta-analysis of outcomes associated with VR psychological interventions and to examine the methodological rigour used in these interventions. Literature search was conducted via Ovid, ProQuest Psychology Journals and ScienceDirect (Psychology) databases. Interventions were required to: be published between 1980 to 2014; use a randomised controlled trial design; be published in a scholarly journal; focused primarily on psychological/behavioural intervention; include validated measures; include reported means and standard deviations of outcome measures; and include one group with clinical/subclinical disorders, syndromes or distressing behaviours. Thirty eligible studies were identified. Random effects meta-analysis found an overall moderate effect size for VR interventions. Individual meta-analyses found an overall large effect size against non-intervention wait-lists and an overall moderate effect size against active interventions. No correlation was found between treatment outcomes and methodological rigour. Limitations may include limited study numbers, the use of a single coder, a need for more in-depth analyses of variation in form VR intervention, and omission of presence as a moderating factor. The current review supports VR interventions as efficacious, promising forms of psychological treatment. Use of reporting guidelines such as the CONSORT and CONSORT-EHEALTH statements should promote greater emphasis on methodological rigour, providing a firm foundation for the further development of clinical VR applications. Copyright © 2014 Elsevier Ltd. All rights reserved.

Temporal analysis of genetic structure to assess population dynamics of reintroduced swift foxes.

PubMed

Cullingham, Catherine I; Moehrenschlager, Axel

2013-12-01

Reintroductions are increasingly used to reestablish species, but a paucity of long-term postrelease monitoring has limited understanding of whether and when viable populations subsequently persist. We conducted temporal genetic analyses of reintroduced populations of swift foxes (Vulpes velox) in Canada (Alberta and Saskatchewan) and the United States (Montana). We used samples collected 4 years apart, 17 years from the initiation of the reintroduction, and 3 years after the conclusion of releases. To assess program success, we genotyped 304 hair samples, subsampled from the known range in 2000 and 2001, and 2005 and 2006, at 7 microsatellite loci. We compared diversity, effective population size, and genetic connectivity over time in each population. Diversity remained stable over time and there was evidence of increasing effective population size. We determined population structure in both periods after correcting for differences in sample sizes. The geographic distribution of these populations roughly corresponded with the original release locations, which suggests the release sites had residual effects on the population structure. However, given that both reintroduction sites had similar source populations, habitat fragmentation, due to cropland, may be associated with the population structure we found. Although our results indicate growing, stable populations, future connectivity analyses are warranted to ensure both populations are not subject to negative small-population effects. Our results demonstrate the importance of multiple sampling years to fully capture population dynamics of reintroduced populations. Análisis Temporal de la Estructura Genética para Evaluar la Dinámica Poblacional de Zorros (Vulpes velox) Reintroducidos. © 2013 Society for Conservation Biology.

Dynamic fatigue of a machinable glass-ceramic

NASA Technical Reports Server (NTRS)

Smyth, K. K.; Magida, M. B.

1982-01-01

To assess the stress corrosion susceptibility of a machinable glass-ceramic, its dynamic fatigue behavior was investigated by measuring its strength as a function of stress rate. Fracture mechanics techniques were used to analyse the results for the purpose of making lifetime predictions for components of this material. This material was concluded to have only moderate resistance to stress in ambient conditions. The effects of specimen size on strength were assessed for the material used in this study: it was concluded that the Weibull edge-flaw scaling law adequately describes the observed strength-size relationship.

Endotoxins in cotton: washing effects and size distribution

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

Olenchock, S.A.; Mull, J.C.; Jones, W.G.

1983-01-01

Endotoxin contamination was measured in washed and unwashed cottons from three distinct growing areas, California, Mississippi, and Texas. The data show differences in endotoxin contamination based upon the geographic source of the cotton. It is also shown that washing bulk cotton before the carding process results in lower endotoxin in the cotton dust. Washing conditions can affect the endotoxin levels, and all size fractions of the airborne dust contain quantifiable endotoxin contamination. Endotoxin analyses provide a simple and reliable method for monitoring the cleanliness of cotton or airborne cotton dusts.

Analysis on ultrashort-pulse laser ablation for nanoscale film of ceramics

NASA Astrophysics Data System (ADS)

Ho, C. Y.; Tsai, Y. H.; Chiou, Y. J.

2017-06-01

This paper uses the dual-phase-lag model to study the ablation characteristics of femtosecond laser processing for nanometer-sized ceramic films. In ultrafast process and ultrasmall size where the two lags occur, a dual-phase-lag can be applied to analyse the ablation characteristics of femtosecond laser processing for materials. In this work, the ablation rates of nanometer-sized lead zirconate titanate (PZT) ceramics are investigated using a dual-phase-lag and the model is solved by Laplace transform method. The results obtained from this work are validated by the available experimental data. The effects of material thermal properties on the ablation characteristics of femtosecond laser processing for ceramics are also discussed.

Birth order, family configuration, and verbal achievement.

PubMed

Breland, H M

1974-12-01

Two samples of National Merit Scholarship participants test in 1962 and the entire population of almost 800,000 participants tested in 1965 were examined. Consistent effects in all 3 groups were observed with respect to both birth order and family size (1st born and those of smaller families scored higher). Control of both socioeconomic variables and maternal age, by analysis of variance as well as by analysis of covariance, failed to alter the relationships. Stepdown analyses suggested that the effects were due to a verbal component and that no differences were attributable to nonverbal factors. Mean test scores were computed for detailed sibship configurations based on birth order, family size, sibling spacing, and sibling sex.

An open trial of mindfulness-based stress reduction for young adults with social anxiety disorder.

PubMed

Hjeltnes, Aslak; Molde, Helge; Schanche, Elisabeth; Vøllestad, Jon; Lillebostad Svendsen, Julie; Moltu, Christian; Binder, Per-Einar

2017-02-01

The present study investigated mindfulness-based stress reduction (MBSR) for young adults with a social anxiety disorder (SAD) in an open trial. Fifty-three young adults in a higher education setting underwent a standard eight-week MBSR program. Eight participants (15%) did not complete the program. Participants reported significant reductions in SAD symptoms and global psychological distress, as well as increases in mindfulness, self-compassion, and self-esteem. Using intention-to-treat (ITT) analyses, effect sizes ranged from large to moderate for SAD symptoms (Cohen's d = 0.80) and global psychological distress (d = 0.61). Completer analyses yielded large effect sizes for SAD symptoms (d = 0.96) and global psychological distress (d = 0.81). The largest effect sizes were found for self-compassion (d = 1.49) and mindfulness (d = 1.35). Two thirds of the participants who were in the clinical range at pretreatment reported either clinically significant change (37%) or reliable improvement (31%) on SAD symptoms after completing the MBSR program, and almost two thirds reported either clinically significant change (37%) or reliable improvement (26%) on global psychological distress. MBSR may be a beneficial intervention for young adults in higher education with SAD, and there is a need for more research on mindfulness and acceptance-based interventions for SAD. © 2016 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

Sample size calculations for randomized clinical trials published in anesthesiology journals: a comparison of 2010 versus 2016.

PubMed

Chow, Jeffrey T Y; Turkstra, Timothy P; Yim, Edmund; Jones, Philip M

2018-06-01

Although every randomized clinical trial (RCT) needs participants, determining the ideal number of participants that balances limited resources and the ability to detect a real effect is difficult. Focussing on two-arm, parallel group, superiority RCTs published in six general anesthesiology journals, the objective of this study was to compare the quality of sample size calculations for RCTs published in 2010 vs 2016. Each RCT's full text was searched for the presence of a sample size calculation, and the assumptions made by the investigators were compared with the actual values observed in the results. Analyses were only performed for sample size calculations that were amenable to replication, defined as using a clearly identified outcome that was continuous or binary in a standard sample size calculation procedure. The percentage of RCTs reporting all sample size calculation assumptions increased from 51% in 2010 to 84% in 2016. The difference between the values observed in the study and the expected values used for the sample size calculation for most RCTs was usually > 10% of the expected value, with negligible improvement from 2010 to 2016. While the reporting of sample size calculations improved from 2010 to 2016, the expected values in these sample size calculations often assumed effect sizes larger than those actually observed in the study. Since overly optimistic assumptions may systematically lead to underpowered RCTs, improvements in how to calculate and report sample sizes in anesthesiology research are needed.

Effect of grain size on optical transmittance of birefringent polycrystalline ceramics

NASA Astrophysics Data System (ADS)

Wen, Tzu-Chien

Polycrystalline ceramics are increasingly used for fabricating windows and domes for the mid infra-red regime (3-5 mum) due to their superior durability as compared to glass and the lower cost of their fabrication and finishing relative to single crystals without significant compromise in optical properties. Due to the noncubic structure, MgF2 and Al2O3 are birefringent ceramics. Birefringence causes scatter of light at the grain boundaries and diminishes in-line transmittance and optical performance. This dissertation presents experimental results and analyses of the grain-size and wavelength dependence of the in-line transmittance of polycrystalline MgF2 and Al2O3. Chapter 2 presents experimental results and analyses of light transmission in polycrystalline MgF2 as a function of the mean grain size at different wavelengths. The scattering coefficient of polycrystalline MgF 2 increased linearly with the mean grain size and inversely with the square of the wavelength of light. These trends are consistent with theoretical models based on both a limiting form of the Raleigh-Gans-Debye theory of particle scattering and light retardation theories that take refractive-index variations along the light path. Chapter 3 investigates the applicability of particle light scattering theories to light attenuation in birefringent polycrystalline ceramics by measuring light transmittance in a model two-phase system. The system consisted of microspheres of silica dispersed in a solution of glycerol in water. It was found that RGD theory showed the systematic deviation for higher particle volume fraction (φ > 0.2) and larger particle size (d p > 1 mum). This result suggested that light scattering models based on single particle scattering are unlikely to provide viable physical explanation for the effect of grain size on light transmittance in birefringent polycrystalline ceramics due to the high volume fraction in dense polycrystalline ceramics. Chapter 4 analyses light transmission properties of polycrystalline Al 2O3 using theories of wave propagation in random media. Fully dense polycrystalline Al2O3 was fabricated using a pressure filtration method. By obtaining the Delta n2 measured from EBSD, the wave retardation theories of Raman and Viswanathan and Kahan et al. provided upper and lower bounds for the theoretical predictions of light transmittance as a function of mean intercept length.

Declining body size: a third universal response to warming?

PubMed

Gardner, Janet L; Peters, Anne; Kearney, Michael R; Joseph, Leo; Heinsohn, Robert

2011-06-01

A recently documented correlate of anthropogenic climate change involves reductions in body size, the nature and scale of the pattern leading to suggestions of a third universal response to climate warming. Because body size affects thermoregulation and energetics, changing body size has implications for resilience in the face of climate change. A review of recent studies shows heterogeneity in the magnitude and direction of size responses, exposing a need for large-scale phylogenetically controlled comparative analyses of temporal size change. Integrative analyses of museum data combined with new theoretical models of size-dependent thermoregulatory and metabolic responses will increase both understanding of the underlying mechanisms and physiological consequences of size shifts and, therefore, the ability to predict the sensitivities of species to climate change. Copyright © 2011 Elsevier Ltd. All rights reserved.

Influence of test capacitor features on piezoelectric and dielectric measurement of ferroelectric films.

PubMed

Wang, Zhihong; Lau, Gih Keong; Zhu, Weiguang; Chao, Chen

2006-01-01

This paper presents both theoretical and numerical analyses of the piezoelectric and dielectric responses of a highly idealized film-on-substrate system, namely, a polarized ferroelectric film perfectly bonded to an elastic silicon substrate. It shows that both effective dielectric and piezoelectric properties of the films change with the size and configuration of the test capacitor. There exists a critical electrode size that is smaller than the diameter of the commonly used substrate. The effective film properties converge to their respective constrained values as capacitor size increases to the critical size. If capacitor size is smaller than the critical size, the surface displacement at the top electrode deviates from the net thickness change in response to an applied voltage because the film is deformable at the film/substrate interface. The constrained properties of the films depend only on those of bulk ferroelectrics but are independent of film thickness and substrate properties. The finding of the critical capacitor size together with analytical expressions of the constrained properties makes it possible to realize consistent measurement of piezoelectric and dielectric properties of films. A surface scanning technique is recommended to measure the profile of piezoresponses of the film so that the constrained properties of the film can be identified accurately.

Cryoprotectant choice and analyses of freeze-drying drug suspension of nanoparticles with functional stabilisers.

PubMed

Wang, Lulu; Ma, Yingying; Gu, Yu; Liu, Yangyang; Zhao, Juan; Yan, Beibei; Wang, Yancai

2018-04-19

Freeze-drying is an effective way to improve long-term physical stability of nanosuspension in drug delivery applications. Nanosuspension also known as suspension of nanoparticles. In this study, the effect of freeze-drying with different cryoprotectants on the physicochemical characteristics of resveratrol (RSV) nanosuspension and quercetin (QUE) nanosuspension was evaluated. D-α-tocopheryl polyethylene glycol succinate (TPGS) and folate-modified distearoylphosphatidyl ethanolamine-polyethylene glycol (DSPE-PEG-FA) were selected as functional stabilisers formulated nanosuspension which were prepared by anti-solvent precipitation method. RSV nanoparticle size and QUE nanoparticle size were about 210 and 110 nm, respectively. The AFM and TEM results of nanosuspension showed uniform and irregular shape particles. After freeze-drying, the optimal concentration of four cryoprotectants was determined by the particle size of re-dispersed nanoparticles. The dissolution profile of drug nanoparticle significantly showed approximately at a 6-8-fold increase dissolution rate. Moreover, TPGS and DSPE-PEG-FA stabilised RSV nanosuspension and QUE nanosuspension samples showed better effect on long-term physical stability.

The effectiveness of a new algorithm on a three-dimensional finite element model construction of bone trabeculae in implant biomechanics.

PubMed

Sato, Y; Teixeira, E R; Tsuga, K; Shindoi, N

1999-08-01

More validity of finite element analysis (FEA) in implant biomechanics requires element downsizing. However, excess downsizing needs computer memory and calculation time. To evaluate the effectiveness of a new algorithm established for more valid FEA model construction without downsizing, three-dimensional FEA bone trabeculae models with different element sizes (300, 150 and 75 micron) were constructed. Four algorithms of stepwise (1 to 4 ranks) assignment of Young's modulus accorded with bone volume in the individual cubic element was used and then stress distribution against vertical loading was analysed. The model with 300 micron element size, with 4 ranks of Young's moduli accorded with bone volume in each element presented similar stress distribution to the model with the 75 micron element size. These results show that the new algorithm was effective, and the use of the 300 micron element for bone trabeculae representation was proposed, without critical changes in stress values and for possible savings on computer memory and calculation time in the laboratory.

Iodine and mental development of children 5 years old and under: a systematic review and meta-analysis.

PubMed

Bougma, Karim; Aboud, Frances E; Harding, Kimberly B; Marquis, Grace S

2013-04-22

Several reviews and meta-analyses have examined the effects of iodine on mental development. None focused on young children, so they were incomplete in summarizing the effects on this important age group. The current systematic review therefore examined the relationship between iodine and mental development of children 5 years old and under. A systematic review of articles using Medline (1980-November 2011) was carried out. We organized studies according to four designs: (1) randomized controlled trial with iodine supplementation of mothers; (2) non-randomized trial with iodine supplementation of mothers and/or infants; (3) prospective cohort study stratified by pregnant women's iodine status; (4) prospective cohort study stratified by newborn iodine status. Average effect sizes for these four designs were 0.68 (2 RCT studies), 0.46 (8 non-RCT studies), 0.52 (9 cohort stratified by mothers' iodine status), and 0.54 (4 cohort stratified by infants' iodine status). This translates into 6.9 to 10.2 IQ points lower in iodine deficient children compared with iodine replete children. Thus, regardless of study design, iodine deficiency had a substantial impact on mental development. Methodological concerns included weak study designs, the omission of important confounders, small sample sizes, the lack of cluster analyses, and the lack of separate analyses of verbal and non-verbal subtests. Quantifying more precisely the contribution of iodine deficiency to delayed mental development in young children requires more well-designed randomized controlled trials, including ones on the role of iodized salt.

Anxiety Outcomes after Physical Activity Interventions: Meta-Analysis Findings

PubMed Central

Conn, Vicki S.

2011-01-01

Background Although numerous primary studies have documented the mental health benefits of physical activity (PA), no previous quantitative synthesis has examined anxiety outcomes of interventions to increase PA. Objectives This meta-analysis integrates extant research about anxiety outcomes from interventions to increase PA among healthy adults. Method Extensive literature searching located published and unpublished PA intervention studies with anxiety outcomes. Eligible studies reported findings from interventions designed to increase PA delivered to healthy adults without anxiety disorders. Data were coded from primary studies. Random-effects meta-analytic procedures were completed. Exploratory moderator analyses using meta-analysis ANOVA and regression analogues were conducted to determine if report, methods, sample, or intervention characteristics were associated with differences in anxiety outcomes. Results Data were synthesized across 3,289 subjects from 19 eligible reports. The overall mean anxiety effect size (d-index) for two-group comparisons was 0.22 with significant heterogeneity (Q = 32.15). Exploratory moderator analyses found larger anxiety improvement effect sizes among studies that included larger samples, used random allocation of subjects to treatment and control conditions, targeted only PA behavior instead of multiple health behaviors, included supervised exercise (vs. home-based PA), used moderate or high-intensity instead of low-intensity PA, and suggested subjects exercise at a fitness facility (vs. home) following interventions. Discussion These findings document that some interventions can decrease anxiety symptoms among healthy adults. Exploratory moderator analyses suggest possible directions for future primary research to compare interventions in randomized trials to confirm causal relationships. PMID:20410849

PSYCHOLOGICAL TREATMENT OF DEPRESSION IN COLLEGE STUDENTS: A METAANALYSIS

PubMed Central

Cuijpers, Pim; Cristea, Ioana A.; Ebert, David D.; Koot, Hans M.; Auerbach, Randy P.; Bruffaerts, Ronny; Kessler, Ronald C.

2015-01-01

Background Expanded efforts to detect and treat depression among college students, a peak period of onset, have the potential to bear high human capital value from a societal perspective because depression increases college withdrawal rates. However, it is not clear whether evidence-based depression therapies are as effective in college students as in other adult populations. The higher levels of cognitive functioning and IQ and higher proportions of first-onset cases might lead to treatment effects being different among college students relative to the larger adult population. Methods We conducted a metaanalysis of randomized trials comparing psychological treatments of depressed college students relative to control groups and compared effect sizes in these studies to those in trials carried out in unselected populations of depressed adults. Results The 15 trials on college students satisfying study inclusion criteria included 997 participants. The pooled effect size of therapy versus control was g = 0.89 (95% CI: 0.66~1.11; NNT = 2.13) with moderate heterogeneity (I2 = 57; 95% CI: 23~72). None of these trials had low risk of bias. Effect sizes were significantly larger when students were not remunerated (e.g. money, credit), received individual versus group therapy, and were in trials that included a waiting list control group. No significant difference emerged in comparing effect sizes among college students versus adults either in simple mean comparisons or in multivariate metaregression analyses. Conclusions This metaanalysis of trials examining psychological treatments of depression in college students suggests that these therapies are effective and have effect sizes comparable to trials carried out among depressed adults. PMID:26682536

Large-scale replication study reveals a limit on probabilistic prediction in language comprehension.

PubMed

Nieuwland, Mante S; Politzer-Ahles, Stephen; Heyselaar, Evelien; Segaert, Katrien; Darley, Emily; Kazanina, Nina; Von Grebmer Zu Wolfsthurn, Sarah; Bartolozzi, Federica; Kogan, Vita; Ito, Aine; Mézière, Diane; Barr, Dale J; Rousselet, Guillaume A; Ferguson, Heather J; Busch-Moreno, Simon; Fu, Xiao; Tuomainen, Jyrki; Kulakova, Eugenia; Husband, E Matthew; Donaldson, David I; Kohút, Zdenko; Rueschemeyer, Shirley-Ann; Huettig, Falk

2018-04-03

Do people routinely pre-activate the meaning and even the phonological form of upcoming words? The most acclaimed evidence for phonological prediction comes from a 2005 Nature Neuroscience publication by DeLong, Urbach and Kutas, who observed a graded modulation of electrical brain potentials (N400) to nouns and preceding articles by the probability that people use a word to continue the sentence fragment ('cloze'). In our direct replication study spanning 9 laboratories ( N =334), pre-registered replication-analyses and exploratory Bayes factor analyses successfully replicated the noun-results but, crucially, not the article-results. Pre-registered single-trial analyses also yielded a statistically significant effect for the nouns but not the articles. Exploratory Bayesian single-trial analyses showed that the article-effect may be non-zero but is likely far smaller than originally reported and too small to observe without very large sample sizes. Our results do not support the view that readers routinely pre-activate the phonological form of predictable words. © 2018, Nieuwland et al.

Large-scale replication study reveals a limit on probabilistic prediction in language comprehension

PubMed Central

Politzer-Ahles, Stephen; Heyselaar, Evelien; Segaert, Katrien; Darley, Emily; Kazanina, Nina; Von Grebmer Zu Wolfsthurn, Sarah; Bartolozzi, Federica; Kogan, Vita; Ito, Aine; Mézière, Diane; Barr, Dale J; Rousselet, Guillaume A; Ferguson, Heather J; Busch-Moreno, Simon; Fu, Xiao; Tuomainen, Jyrki; Kulakova, Eugenia; Husband, E Matthew; Donaldson, David I; Kohút, Zdenko; Rueschemeyer, Shirley-Ann; Huettig, Falk

2018-01-01

Do people routinely pre-activate the meaning and even the phonological form of upcoming words? The most acclaimed evidence for phonological prediction comes from a 2005 Nature Neuroscience publication by DeLong, Urbach and Kutas, who observed a graded modulation of electrical brain potentials (N400) to nouns and preceding articles by the probability that people use a word to continue the sentence fragment (‘cloze’). In our direct replication study spanning 9 laboratories (N=334), pre-registered replication-analyses and exploratory Bayes factor analyses successfully replicated the noun-results but, crucially, not the article-results. Pre-registered single-trial analyses also yielded a statistically significant effect for the nouns but not the articles. Exploratory Bayesian single-trial analyses showed that the article-effect may be non-zero but is likely far smaller than originally reported and too small to observe without very large sample sizes. Our results do not support the view that readers routinely pre-activate the phonological form of predictable words. PMID:29631695

Effects of Pore Distributions on Ductility of Thin-Walled High Pressure Die-Cast Magnesium

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

Choi, Kyoo Sil; Li, Dongsheng; Sun, Xin

2013-06-01

In this paper, a microstructure-based three-dimensional (3D) finite element modeling method is adopted to investigate the effects of porosity in thin-walled high pressure die-cast (HPDC) Magnesium alloys on their ductility. For this purpose, the cross-sections of AM60 casting samples are first examined using optical microscope and X-ray tomography to obtain the general information on the pore distribution features. The experimentally observed pore distribution features are then used to generate a series of synthetic microstructure-based 3D finite element models with different pore volume fractions and pore distribution features. Shear and ductile damage models are adopted in the finite element analyses tomore » induce the fracture by element removal, leading to the prediction of ductility. The results in this study show that the ductility monotonically decreases as the pore volume fraction increases and that the effect of ‘skin region’ on the ductility is noticeable under the condition of same local pore volume fraction in the center region of the sample and its existence can be beneficial for the improvement of ductility. The further synthetic microstructure-based 3D finite element analyses are planned to investigate the effects of pore size and pore size distribution.« less

Effects of caffeine and aspirin on light resistance training performance, perceived exertion, and pain perception.

PubMed

Hudson, Geoffrey M; Green, J Matt; Bishop, Phillip A; Richardson, Mark T

2008-11-01

This study compared independent effects of caffeine and aspirin on muscular endurance (repetitions), heart rate (HR), perceived exertion (RPE), and perceived pain index (PPI) during light resistance training bouts performed to volitional failure. It was hypothesized that the hypoalgesic properties of these ergogenic aids would decrease pain perception and potentially result in enhanced performance. College-aged men (n = 15) participated in a within-subjects, double-blind study with three independent, counterbalanced sessions wherein aspirin (10 mg x kg(-1)), caffeine (6 mg x kg(-1)), or matched placebo were ingested 1 hour before exercise, and RPE, HR, PPI, and repetitions (per set and total per exercise) were recorded at 100% of individual, predetermined, 12-repetition maximum for leg extensions (LE) and seated arm curls (AC). Repeated-measures analyses of variance were used for between-trial comparisons. Caffeine resulted in significantly greater (p < 0.05) HR (LE and AC), total repetitions (LE), and repetitions in set 1 (LE and AC) compared with aspirin and placebo. Aspirin resulted in significantly higher PPI in set 1 (LE). In LE, 47% of participants' performance exceeded the predetermined effect size (>or= 5 repetitions) for total repetitions, with 53% exceeding the effect size (>or= 2 repetitions) for repetitions in set 1 with caffeine (vs. placebo). In AC, 53% (total repetitions) and 47% (set 1 repetitions) of participants exceeded effect sizes with caffeine (vs. placebo), with only 13% experiencing decrements in performance (total repetitions). Aspirin also produced a higher PPI and RPE overall and in set 1 (vs. placebo). This study demonstrates that caffeine significantly enhanced resistance training performance in LE and AC, whereas aspirin did not. Athletes may improve their resistance training performance by acute ingestion of caffeine. As with most ergogenic aids, our analyses indicate that individual responses vary greatly.

Cost-effectiveness analysis of telephone-based support for the management of pressure ulcers in people with spinal cord injury in India and Bangladesh.

PubMed

Arora, M; Harvey, L A; Glinsky, J V; Chhabra, H S; Hossain, M S; Arumugam, N; Bedi, P K; Cameron, I D; Hayes, A J

2017-08-15

To determine from a societal perspective the cost-effectiveness and cost-utility of telephone-based support for management of pressure ulcers. Cost-effectiveness and cost-utility analysis of a randomised clinical trial. Tertiary centre in India and Bangladesh. An economic evaluation was conducted alongside a randomised clinical trial comparing 12 weeks of telephone-based support (intervention group) with usual care (control group). The analyses evaluated costs and health outcomes in terms of cm 2 reduction of pressure ulcers size and quality-adjusted life years (QALYs) gained. All costs were in Indian Rupees (INR) and then converted to US dollars (USD). The mean (95% confidence interval) between-group difference for the reduction in size of pressure ulcers was 0.53 (-3.12 to 4.32) cm 2 , favouring the intervention group. The corresponding QALYs were 0.027 (0.004-0.051), favouring the intervention group. The mean total cost per participant in the intervention group was INR 43 781 (USD 2460) compared to INR 42 561 (USD 2391) for the control group. The per participant cost of delivering the intervention was INR 2110 (USD 119). The incremental cost-effectiveness ratio was INR 2306 (USD 130) per additional cm 2 reduction in the size of the pressure ulcer and INR 44 915 (USD 2523) per QALY gained. In terms of QALYs, telephone-based support to help people manage pressure ulcers at home provides good value for money and has an 87% probability of being cost-effective, based on 3 times gross domestic product. Sensitivity analyses were performed using the overall cost data with and without productivity costs, and did not alter this conclusion.Spinal Cord advance online publication, 15 August 2017; doi:10.1038/sc.2017.87.

Effect of Exergames on Depression: A Systematic Review and Meta-Analysis.

PubMed

Li, Jinhui; Theng, Yin-Leng; Foo, Schubert

2016-01-01

Depression is a major public health concern in current society. In recent years many studies began to investigate the potential benefits of exergames on depression. The current study aimed to provide a systematic review to synthesize the existing studies and discover the overall effect size of exergames on treating depression. A comprehensive literature search was conducted among major bibliographic databases in computer technology, psychology, and medical science. Key study characteristics of participants, interventions, and experiment were extracted in the systematic review. Both studies using independent groups and matched groups were included in meta-analysis. Overall effect size of Hedges' g was calculated, followed by subgroup analyses. Nine studies included in the review, while eight studies applying exergames of Nintendo's Wii or Wii Fit. A random effects meta-analysis on eight studies resulted an overall significant effect size of g = 0.21. Demographic factors, depression severity, number of session, and game type were found to be significant moderators for the effectiveness. The study has not only supported the positive effect of exergames on alleviating depression, but also provided many theoretical and practical implications for health professionals and police makers. More rigorous experimental controlled studies are needed in this new research field.

A meta-analytic review on social relationships and suicidal ideation among older adults.

PubMed

Chang, Qingsong; Chan, Chee Hon; Yip, Paul S F

2017-10-01

Social relationships play an important role in mental health as well as suicidal ideation in later life. In contrast with the other well-established risk factors, despite an increasing number of related studies, no meta-analyses focusing on social relationships and late-life suicidal ideation have been published. Synthesis of data across the studies using different measurements of social relationships would allow for comparison of the effects on late-life suicidal ideation that have not been studied before. Therefore, we conducted a meta-analysis on the studies published between January 1, 2000 and November 31, 2016 extracted from 7 medical and social science databases. 31 studies with 83 estimates of Odds Ratios ("ORs") on the associations between social relationships and late-life suicidal ideation were identified to compute effect sizes using a random-effect model. Sensitivity analyses were also performed to evaluate their heterogeneity and bias. Moderator analyses were further conducted to determine moderating factors of the associations. Eventually, across the 31 studies (203,152 participants), the overall random effect size was OR = 1.57(95% CI [1.40, 1.76]), indicating a 57% likelihood increase of suicidal ideation for elderly participants with discordant social relationships. The functional measures (OR = 1.77; 95%CI [1.48, 2.10]) of social relationships, however, were more predictive than structural measures (OR = 1.37; 95%CI [1.25, 1.51]). Among all the measures of social relationships, elderly mistreatment (OR = 2.31; 95%CI [1.81, 2.94]) had the strongest effect size, followed by perceived loneliness (OR = 2.24; 95%CI [1.73, 2.90]) and poorly perceived social support (OR = 1.59; 95% CI [1.37, 1.83]). The associations between social relationships and late-life suicidal ideation were moderated by country income levels, social-cultural context, study types, and various measurements of social relationships. More importantly, our study is the first meta-analysis to provide significant evidence for improving social relationships, especially in perceived bonds, is a promising strategy in reducing late-life suicide risks. Copyright © 2017 Elsevier Ltd. All rights reserved.

Martial arts as a mental health intervention for children? Evidence from the ECLS-K

PubMed Central

Strayhorn, Joseph M; Strayhorn, Jillian C

2009-01-01

Background Martial arts studios for children market their services as providing mental health outcomes such as self-esteem, self-confidence, concentration, and self-discipline. It appears that many parents enroll their children in martial arts in hopes of obtaining such outcomes. The current study used the data from the Early Childhood Longitudinal Study, Kindergarten class of 1998-1999, to assess the effects of martial arts upon such outcomes as rated by classroom teachers. Methods The Early Childhood Longitudinal Study used a multistage probability sampling design to gather a sample representative of U.S. children attending kindergarten beginning 1998. We made use of data collected in the kindergarten, 3rd grade, and 5th grade years. Classroom behavior was measured by a rating scale completed by teachers; participation in martial arts was assessed as part of a parent interview. The four possible combinations of participation and nonparticipation in martial arts at time 1 and time 2 for each analysis were coded into three dichotomous variables; the set of three variables constituted the measure of participation studied through regression. Multiple regression was used to estimate the association between martial arts participation and change in classroom behavior from one measurement occasion to the next. The change from kindergarten to third grade was studied as a function of martial arts participation, and the analysis was replicated studying behavior change from third grade to fifth grade. Cohen's f2 effect sizes were derived from these regressions. Results The martial arts variable failed to show a statistically significant effect on behavior, in either of the regression analyses; in fact, the f2 effect size for martial arts was 0.000 for both analyses. The 95% confidence intervals for regression coefficients for martial arts variables have upper and lower bounds that are all close to zero. The analyses not only fail to reject the null hypothesis, but also render unlikely a population effect size that differs greatly from zero. Conclusion The data from the ECLS-K fail to support enrolling children in martial arts to improve mental health outcomes as measured by classroom teachers. PMID:19828027

Martial arts as a mental health intervention for children? Evidence from the ECLS-K.

PubMed

Strayhorn, Joseph M; Strayhorn, Jillian C

2009-10-14

Martial arts studios for children market their services as providing mental health outcomes such as self-esteem, self-confidence, concentration, and self-discipline. It appears that many parents enroll their children in martial arts in hopes of obtaining such outcomes. The current study used the data from the Early Childhood Longitudinal Study, Kindergarten class of 1998-1999, to assess the effects of martial arts upon such outcomes as rated by classroom teachers. The Early Childhood Longitudinal Study used a multistage probability sampling design to gather a sample representative of U.S. children attending kindergarten beginning 1998. We made use of data collected in the kindergarten, 3rd grade, and 5th grade years. Classroom behavior was measured by a rating scale completed by teachers; participation in martial arts was assessed as part of a parent interview. The four possible combinations of participation and nonparticipation in martial arts at time 1 and time 2 for each analysis were coded into three dichotomous variables; the set of three variables constituted the measure of participation studied through regression. Multiple regression was used to estimate the association between martial arts participation and change in classroom behavior from one measurement occasion to the next. The change from kindergarten to third grade was studied as a function of martial arts participation, and the analysis was replicated studying behavior change from third grade to fifth grade. Cohen's f2 effect sizes were derived from these regressions. The martial arts variable failed to show a statistically significant effect on behavior, in either of the regression analyses; in fact, the f2 effect size for martial arts was 0.000 for both analyses. The 95% confidence intervals for regression coefficients for martial arts variables have upper and lower bounds that are all close to zero. The analyses not only fail to reject the null hypothesis, but also render unlikely a population effect size that differs greatly from zero. The data from the ECLS-K fail to support enrolling children in martial arts to improve mental health outcomes as measured by classroom teachers.

Do Nondomestic Undergraduates Choose a Major Field in Order to Maximize Grade Point Averages?

ERIC Educational Resources Information Center

Bergman, Matthew E.; Fass-Holmes, Barry

2016-01-01

The authors investigated whether undergraduates attending an American West Coast public university who were not U.S. citizens (nondomestic) maximized their grade point averages (GPA) through their choice of major field. Multiple regression hierarchical linear modeling analyses showed that major field's effect size was small for these…

Estimating the Difference between Published and Unpublished Effect Sizes: A Meta-Review

ERIC Educational Resources Information Center

Polanin, Joshua R.; Tanner-Smith, Emily E.; Hennessy, Emily A.

2016-01-01

Practitioners and policymakers rely on meta-analyses to inform decision making around the allocation of resources to individuals and organizations. It is therefore paramount to consider the validity of these results. A well-documented threat to the validity of research synthesis results is the presence of publication bias, a phenomenon where…

Estimating the Difference between Published and Unpublished Effect Sizes: A Meta-Review

ERIC Educational Resources Information Center

Polanin, Joshua R.; Tanner-Smith, Emily E.; Hennessy, Emily A.

2016-01-01

Practitioners and policymakers rely on meta-analyses to inform decision-making around the allocation of resources to individuals and organizations. It is therefore paramount to consider the validity of these results. A well-documented threat to the validity of research synthesis results is the presence of publication bias, a phenomenon where…

Use of "t"-Test and ANOVA in Career-Technical Education Research

ERIC Educational Resources Information Center

Rojewski, Jay W.; Lee, In Heok; Gemici, Sinan

2012-01-01

Use of t-tests and analysis of variance (ANOVA) procedures in published research from three scholarly journals in career and technical education (CTE) during a recent 5-year period was examined. Information on post hoc analyses, reporting of effect size, alpha adjustments to account for multiple tests, power, and examination of assumptions…

On measuring bird habitat: influence of observer variability and sample size

Treesearch

William M. Block; Kimberly A. With; Michael L. Morrison

1987-01-01

We studied the effects of observer variability when estimating vegetation characteristics at 75 0.04-ha bird plots. Observer estimates were significantly different for 31 of 49 variables. Multivariate analyses showed significant interobserver differences for five of the seven classes of variables studied. Variable classes included the height, number, and diameter of...

Meta-Analysis of Explicit Memory Studies in Populations with Intellectual Disability

ERIC Educational Resources Information Center

Lifshitz, Hefziba; Shtein, Sarit; Weiss, Izhak; Vakil, Eli

2011-01-01

This meta-analysis combines the effect size (ES) of 40 explicit memory experiments in populations with intellectual disability (ID). Eight meta-analyses were performed, as well as contrast tests between ES. The explicit memory of participants with ID was inferior to that of participants with typical development (TD). Relatively preserved explicit…

Effect Size Indices for Analyses of Measurement Equivalence: Understanding the Practical Importance of Differences between Groups

ERIC Educational Resources Information Center

Nye, Christopher D.; Drasgow, Fritz

2011-01-01

Because of the practical, theoretical, and legal implications of differential item functioning (DIF) for organizational assessments, studies of measurement equivalence are a necessary first step before scores can be compared across individuals from different groups. However, commonly recommended criteria for evaluating results from these analyses…

Technology, safety, and costs of decommissioning reference nuclear research and test reactors: sensitivity of decommissioning radiation exposure and costs to selected parameters

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

Konzek, G.J.

1983-07-01

Additional analyses of decommissioning at the reference research and test (R and T) reactors and analyses of five recent reactor decommissionings are made that examine some parameters not covered in the initial study report (NUREG/CR-1756). The parameters examined for decommissioning are: (1) the effect on costs and radiation exposure of plant size and/or type; (2) the effects on costs of increasing disposal charges and of unavailability of waste disposal capacity at licensed waste disposal facilities; and (3) the costs of and the available alternatives for the disposal of nuclear R and T reactor fuel assemblies.

The Extent and Consequences of P-Hacking in Science

PubMed Central

Head, Megan L.; Holman, Luke; Lanfear, Rob; Kahn, Andrew T.; Jennions, Michael D.

2015-01-01

A focus on novel, confirmatory, and statistically significant results leads to substantial bias in the scientific literature. One type of bias, known as “p-hacking,” occurs when researchers collect or select data or statistical analyses until nonsignificant results become significant. Here, we use text-mining to demonstrate that p-hacking is widespread throughout science. We then illustrate how one can test for p-hacking when performing a meta-analysis and show that, while p-hacking is probably common, its effect seems to be weak relative to the real effect sizes being measured. This result suggests that p-hacking probably does not drastically alter scientific consensuses drawn from meta-analyses. PMID:25768323

The history of effective population size and genetic diversity in the Yellowstone grizzly (Ursus arctos): implications for conservation.

PubMed

Miller, Craig R; Waits, Lisette P

2003-04-01

Protein, mtDNA, and nuclear microsatellite DNA analyses have demonstrated that the Yellowstone grizzly bear has low levels of genetic variability compared with other Ursus arctos populations. Researchers have attributed this difference to inbreeding during a century of anthropogenic isolation and population size reduction. We test this hypothesis and assess the seriousness of genetic threats by generating microsatellite data for 110 museum specimens collected between 1912 and 1981. A loss of variability is detected, but it is much less severe than hypothesized. Variance in allele frequencies over time is used to estimate an effective population size of approximately 80 across the 20th century and >100 currently. The viability of the population is unlikely to be substantially reduced by genetic factors in the next several generations. However, gene flow from outside populations will be beneficial in avoiding inbreeding and the erosion of genetic diversity in the future.

Closure and ratio correlation analysis of lunar chemical and grain size data

NASA Technical Reports Server (NTRS)

Butler, J. C.

1976-01-01

Major element and major element plus trace element analyses were selected from the lunar data base for Apollo 11, 12 and 15 basalt and regolith samples. Summary statistics for each of the six data sets were compiled, and the effects of closure on the Pearson product moment correlation coefficient were investigated using the Chayes and Kruskal approximation procedure. In general, there are two types of closure effects evident in these data sets: negative correlations of intermediate size which are solely the result of closure, and correlations of small absolute value which depart significantly from their expected closure correlations which are of intermediate size. It is shown that a positive closure correlation will arise only when the product of the coefficients of variation is very small (less than 0.01 for most data sets) and, in general, trace elements in the lunar data sets exhibit relatively large coefficients of variation.

Modulated grayscale UV pattern for uniform photopolymerization based on a digital micromirror device system

NASA Astrophysics Data System (ADS)

Yoon, Jinsik; Kim, Kibeom; Park, Wook

2017-07-01

We present an essential method for generating microparticles uniformly in a single ultraviolet (UV) light exposure area for optofluidic maskless lithography. In the optofluidic maskless lithography process, the productivity of monodisperse microparticles depends on the size of the UV exposure area. An effective fabrication area is determined by the size of the UV intensity profile map, satisfying the required uniformity of UV intensity. To increase the productivity of monodisperse microparticles in optofluidic maskless lithography, we expanded the effective UV exposure area by modulating the intensity of the desired UV light pattern based on the premeasured UV intensity profile map. We verified the improvement of the uniformity of the microparticles generated by the proposed modulation technique, providing histogram analyses of the conjugated fluorescent intensities and the sizes of the microparticles. Additionally, we demonstrated the generation of DNA uniformly encapsulated in microparticles.

Methods for estimating confidence intervals in interrupted time series analyses of health interventions.

PubMed

Zhang, Fang; Wagner, Anita K; Soumerai, Stephen B; Ross-Degnan, Dennis

2009-02-01

Interrupted time series (ITS) is a strong quasi-experimental research design, which is increasingly applied to estimate the effects of health services and policy interventions. We describe and illustrate two methods for estimating confidence intervals (CIs) around absolute and relative changes in outcomes calculated from segmented regression parameter estimates. We used multivariate delta and bootstrapping methods (BMs) to construct CIs around relative changes in level and trend, and around absolute changes in outcome based on segmented linear regression analyses of time series data corrected for autocorrelated errors. Using previously published time series data, we estimated CIs around the effect of prescription alerts for interacting medications with warfarin on the rate of prescriptions per 10,000 warfarin users per month. Both the multivariate delta method (MDM) and the BM produced similar results. BM is preferred for calculating CIs of relative changes in outcomes of time series studies, because it does not require large sample sizes when parameter estimates are obtained correctly from the model. Caution is needed when sample size is small.

Reporting Practices and Use of Quantitative Methods in Canadian Journal Articles in Psychology.

PubMed

Counsell, Alyssa; Harlow, Lisa L

2017-05-01

With recent focus on the state of research in psychology, it is essential to assess the nature of the statistical methods and analyses used and reported by psychological researchers. To that end, we investigated the prevalence of different statistical procedures and the nature of statistical reporting practices in recent articles from the four major Canadian psychology journals. The majority of authors evaluated their research hypotheses through the use of analysis of variance (ANOVA), t -tests, and multiple regression. Multivariate approaches were less common. Null hypothesis significance testing remains a popular strategy, but the majority of authors reported a standardized or unstandardized effect size measure alongside their significance test results. Confidence intervals on effect sizes were infrequently employed. Many authors provided minimal details about their statistical analyses and less than a third of the articles presented on data complications such as missing data and violations of statistical assumptions. Strengths of and areas needing improvement for reporting quantitative results are highlighted. The paper concludes with recommendations for how researchers and reviewers can improve comprehension and transparency in statistical reporting.

Climate alters intraspecific variation in copepod effect traits through pond food webs.

PubMed

Charette, Cristina; Derry, Alison M

2016-05-01

Essential fatty acids (EFAs) are primarily generated by phytoplankton in aquatic ecosystems, and can limit the growth, development, and reproduction of higher consumers. Among the most critical of the EFAs are highly unsaturated fatty acids (HUFAs), which are only produced by certain groups of phytoplankton. Changing environmental conditions can alter phytoplankton community and fatty acid composition and affect the HUFA content of higher trophic levels. Almost no research has addressed intraspecific variation in HUFAs in zooplankton, nor intraspecific relationships of HUFAs with body size and fecundity. This is despite that intraspecific variation in HUFAs can exceed interspecific variation and that intraspecific trait variation in body size and fecundity is increasingly recognized to have an important role in food web ecology (effect traits). Our study addressed the relative influences of abiotic selection and food web effects associated with climate change on intraspecific differences and interrelationships between HUFA content, body size, and fecundity of freshwater copepods. We applied structural equation modeling and regression analyses to intraspecific variation in a dominant calanoid copepod, Leptodiatomus minutus, among a series of shallow north-temperate ponds. Climate-driven diurnal temperature fluctuations favored the coexistence of diversity of phytoplankton groups with different temperature optima and nutritive quality. This resulted in unexpected positive relationships between temperature, copepod DHA content and body size. Temperature correlated positively with diatom biovolume, and mediated relationships between copepod HUFA content and body size, and between copepod body size and fecundity. The presence of brook trout further accentuated these positive effects in warm ponds, likely through nutrient cycling and stimulation of phytoplankton resources. Climate change may have previously unrecognized positive effects on freshwater copepod DHA content, body size, and fecundity in the small, shallow bodies of inland waters that are commonly found in north-temperate landscapes.

A Methodological Review of US Budget-Impact Models for New Drugs.

PubMed

Mauskopf, Josephine; Earnshaw, Stephanie

2016-11-01

A budget-impact analysis is required by many jurisdictions when adding a new drug to the formulary. However, previous reviews have indicated that adherence to methodological guidelines is variable. In this methodological review, we assess the extent to which US budget-impact analyses for new drugs use recommended practices. We describe recommended practice for seven key elements in the design of a budget-impact analysis. Targeted literature searches for US studies reporting estimates of the budget impact of a new drug were performed and we prepared a summary of how each study addressed the seven key elements. The primary finding from this review is that recommended practice is not followed in many budget-impact analyses. For example, we found that growth in the treated population size and/or changes in disease-related costs expected during the model time horizon for more effective treatments was not included in several analyses for chronic conditions. In addition, all drug-related costs were not captured in the majority of the models. Finally, for most studies, one-way sensitivity and scenario analyses were very limited, and the ranges used in one-way sensitivity analyses were frequently arbitrary percentages rather than being data driven. The conclusions from our review are that changes in population size, disease severity mix, and/or disease-related costs should be properly accounted for to avoid over- or underestimating the budget impact. Since each budget holder might have different perspectives and different values for many of the input parameters, it is also critical for published budget-impact analyses to include extensive sensitivity and scenario analyses based on realistic input values.

Effect of Mg2+ on acidic calcium phosphate phases grown by electrodeposition

NASA Astrophysics Data System (ADS)

Correia, Matheus Bento; Júnior, José Pedro Gualberto; Macedo, Michelle Cardinale S. S.; Resende, Cristiane Xavier; dos Santos, Euler Araujo

2017-10-01

In this work, the effect of Mg2+ ions on the electrodeposition of dicalcium phosphate dihydrate (DCPD), octacalcium phosphate (OCP) and calcium-deficient hydroxyapatite (CDHA) crystals on a commercially pure titanium (cp-Ti) substrate was evaluated. We demonstrated that Mg2+ ions could change the morphology of the coatings by inhibiting the growth rate of the OCP and CDHA crystals and diminishing the crystallite size of DCPD. The inhibition effect on OCP and CDHA was most likely due to a surface adsorption mechanism since no evidence of a doping process was observed using Rietveld refinement and electron diffraction analyses. Conversely, the presence of Mg2+ ions generated a favorable condition for the nucleation of a new Mg2+-rich DCPD crystal population, presenting smaller crystallite sizes.

Meta-analyses of mood stabilizers, antidepressants and antipsychotics in the treatment of borderline personality disorder: effectiveness for depression and anger symptoms.

PubMed

Mercer, Deanna; Douglass, Alan B; Links, Paul S

2009-04-01

The objective of our study was to complete separate meta-analyses of randomized controlled trials of mood stabilizers, antidepressants and antipsychotics to determine whether these medications are efficacious for depression and anger symptoms in borderline personality disorder (BPD). Studies were obtained from OVID Medline, Cochrane Central Register of Controlled Trials, and PsychInfo. References of all original papers and reviews were searched for additional studies. Index terms included: BPD, randomized controlled trials, drug therapy, medication, and treatment. Studies were included if they were randomized double-blind placebo-controlled trials, published in a peer reviewed journal, had a majority of patients with BPD or included patients with BPD where anger was a target of treatment. Preference was given to studies using outcome measures that were well known, validated, objective, and based on intent-to-treat data. Where available, measures of anger that incorporated verbal and other indirect forms of aggression were utilized. The StatsDirect meta-analysis program was used to calculate an effect size and 95% confidence interval for each study. Mood stabilizers, with the exception of divalproic acid, were found to have a large pooled effect size (-1.75, 95% CI = -2.77 to -0.74) for anger. Divalproic acid and carbamazepine had a moderate effect on depression. Antidepressants had a moderate effect on anger reduction, but a small effect on depression. Antipsychotics had a moderate effect on anger; however aripiprazole had a much larger effect-size than other antipsychotics. Antipsychotics did not have an effect for depression. Sources of variation between studies included length of treatment (5-24 weeks), drop out rates (5% to 65%), proportion of patients in psychotherapy (0-100%) and with comorbid mood disorders (0-100%). Unfortunately most studies excluded patients with alcohol and substance abuse, suicidality, and self-harm behaviors. This may limit the ability to generalize our findings to usual clinical practice.

A meta-analytic review of collaborative inhibition and postcollaborative memory: Testing the predictions of the retrieval strategy disruption hypothesis.

PubMed

Marion, Stéphanie B; Thorley, Craig

2016-11-01

The retrieval strategy disruption hypothesis (Basden, Basden, Bryner, & Thomas, 1997) is the most widely cited theoretical explanation for why the memory performance of collaborative groups is inferior to the pooled performance of individual group members remembering alone (i.e., collaborative inhibition). This theory also predicts that several variables will moderate collaborative inhibition. This meta-analysis tests the veracity of the theory by systematically examining whether or not these variables do moderate the presence and strength of collaborative inhibition. A total of 75 effect sizes from 64 studies were included in the analysis. Collaborative inhibition was found to be a robust effect. Moreover, it was enhanced when remembering took place in larger groups, when uncategorized content items were retrieved, when group members followed free-flowing and free-order procedures, and when group members did not know one another. These findings support the retrieval strategy disruption hypothesis as a general theoretical explanation for the collaborative inhibition effect. Several additional analyses were also conducted to elucidate the potential contributions of other cognitive mechanisms to collaborative inhibition. Some results suggest that a contribution of retrieval inhibition is possible, but we failed to find any evidence to suggest retrieval blocking and encoding specificity impact upon collaborative inhibition effects. In a separate analysis (27 effect sizes), moderating factors of postcollaborative memory performance were examined. Generally, collaborative remembering tends to benefit later individual retrieval. Moderator analyses suggest that reexposure to study material may be partly responsible for this postcollaborative memory enhancement. Some applied implications of the meta-analyses are discussed. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Integrating fragmented evidence by network meta-analysis: relative effectiveness of psychological interventions for adults with post-traumatic stress disorder.

PubMed

Gerger, H; Munder, T; Gemperli, A; Nüesch, E; Trelle, S; Jüni, P; Barth, J

2014-11-01

To summarize the available evidence on the effectiveness of psychological interventions for patients with post-traumatic stress disorder (PTSD). We searched bibliographic databases and reference lists of relevant systematic reviews and meta-analyses for randomized controlled trials that compared specific psychological interventions for adults with PTSD symptoms either head-to-head or against control interventions using non-specific intervention components, or against wait-list control. Two investigators independently extracted the data and assessed trial characteristics. The analyses included 4190 patients in 66 trials. An initial network meta-analysis showed large effect sizes (ESs) for all specific psychological interventions (ESs between -1.10 and -1.37) and moderate effects of psychological interventions that were used to control for non-specific intervention effects (ESs -0.58 and -0.62). ES differences between various types of specific psychological interventions were absent to small (ES differences between 0.00 and 0.27). Considerable between-trial heterogeneity occurred (τ²= 0.30). Stratified analyses revealed that trials that adhered to DSM-III/IV criteria for PTSD were associated with larger ESs. However, considerable heterogeneity remained. Heterogeneity was reduced in trials with adequate concealment of allocation and in large-sized trials. We found evidence for small-study bias. Our findings show that patients with a formal diagnosis of PTSD and those with subclinical PTSD symptoms benefit from different psychological interventions. We did not identify any intervention that was consistently superior to other specific psychological interventions. However, the robustness of evidence varies considerably between different psychological interventions for PTSD, with most robust evidence for cognitive behavioral and exposure therapies.

Cognitive-behavioral therapy for hypochondriasis/health anxiety: a meta-analysis of treatment outcome and moderators.

PubMed

Olatunji, Bunmi O; Kauffman, Brooke Y; Meltzer, Sari; Davis, Michelle L; Smits, Jasper A J; Powers, Mark B

2014-07-01

The present investigation employed meta-analysis to examine the efficacy of cognitive-behavioral therapy (CBT) for hypochondriasis/health anxiety as well as potential moderators that may be associated with outcome. A literature search revealed 15 comparisons among 13 randomized-controlled trials (RCTs) with a total sample size of 1081 participants that met inclusion criteria. Results indicated that CBT outperformed control conditions on primary outcome measures at post-treatment (Hedges's g = 0.95) and at follow-up (Hedges's g = 0.34). CBT also outperformed control conditions on measures of depression at post-treatment (Hedges's g = 0.64) and at follow-up (Hedges's g = 0.35). Moderator analyses revealed that higher pre-treatment severity of hypochondriasis/health anxiety was associated with greater effect sizes at follow-up visits and depression symptom severity was significantly associated with a lower in effect sizes at post-treatment. Although effect size did not vary as a function of blind assessment, smaller effect sizes were observed for CBT vs. treatment as usual control conditions than for CBT vs. waitlist control. A dose response relationship was also observed, such that a greater number of CBT sessions was associated with larger effect sizes at post-treatment. This review indicates that CBT is efficacious in the treatment of hypochondriasis/health anxiety and identifies potential moderators that are associated with outcome. The implications of these findings for further delineating prognostic and prescriptive indicators of CBT for hypochondriasis/health anxiety are discussed. Copyright © 2014 Elsevier Ltd. All rights reserved.

Cleavage fracture in pearlitic eutectoid steel

NASA Astrophysics Data System (ADS)

Alexander, D. J.; Bernstein, I. M.

1989-11-01

The effect of microstructure on flow and fracture properties of fully pearlitic steel has been studied by independently varying the prior austenite grain size and the pearlite interlamellar spacing through appropriate heat treatments. The yield strength is independent of the prior austenite grain size but increases as the interlamellar spacing or the temperature decreases. The microstructural dependence can be explained by using a model which assumes that yielding is controlled by dislocation motion in the ferrite lamellae. The critical tensile stress for cleavage fracture is found to be independent of prior austenite grain size, increasing as the interlamellar spacing decreases. The cleavage fracture stress is independent of temperature for fine pearlite but increases as the temperature decreases for coarse pearlite. The associated fracture in blunt notch specimens initiates at inclusions beneath notch surface near the location of maximum tensile stress. From the size of such inclusions, the effective surface energy for cleavage fracture can be directly calculated and is found to be independent of temperature and prior austenite grain size but to increase as the interlamellar spacing decreases, from about 5 to 13 J/m2 for the range of microstructures and temperatures used in this study. Additional measurements of the effective surface energy and further theoretical analyses of the cleavage process are needed.

Design of Fiber Reinforced Foam Sandwich Panels for Large Ares V Structural Applications

NASA Technical Reports Server (NTRS)

Bednarcyk, Brett A.; Arnold, Steven M.; Hopkins, Dale A.

2010-01-01

The preliminary design of three major structural components within NASA's Ares V heavy lift vehicle using a novel fiber reinforced foam composite sandwich panel concept is presented. The Ares V payload shroud, interstage, and core intertank are designed for minimum mass using this panel concept, which consists of integral composite webs separated by structural foam between two composite facesheets. The HyperSizer structural sizing software, in conjunction with NASTRAN finite element analyses, is used. However, since HyperSizer does not currently include a panel concept for fiber reinforced foam, the sizing was performed using two separate approaches. In the first, the panel core is treated as an effective (homogenized) material, whose properties are provided by the vendor. In the second approach, the panel is treated as a blade stiffened sandwich panel, with the mass of the foam added after completion of the panel sizing. Details of the sizing for each of the three Ares V components are given, and it is demonstrated that the two panel sizing approaches are in reasonable agreement for thinner panel designs, but as the panel thickness increases, the blade stiffened sandwich panel approach yields heavier panel designs. This is due to the effects of local buckling, which are not considered in the effective core property approach.

Effect of Porous Titanium Granules on Bone Regeneration and Primary Stability in Maxillary Sinus: A Human Clinical, Histomorphometric, and Microcomputed Tomography Analyses.

PubMed

Dursun, Ceyda Kanli; Dursun, Erhan; Eratalay, Kenan; Orhan, Kaan; Tatar, Ilkan; Baris, Emre; Tözüm, Tolga Fikret

2016-03-01

The aim of this randomized controlled study was to comparatively analyze the new bone (NB), residual bone, and graft-bone association in bone biopsies retrieved from augmented maxillary sinus sites by histomorphometry and microcomputed tomography (MicroCT) in a split-mouth model to test the efficacy of porous titanium granules (PTG) in maxillary sinus augmentation. Fifteen patients were included in the study and each patient was treated with bilateral sinus augmentation procedure using xenograft (equine origine, granule size 1000-2000 μm) and xenograft (1 g) + PTG (granule size 700-1000 μm, pore size >50 μm) (1 g), respectively. After a mean of 8.4 months, 30 bone biopsies were retrieved from the implant sites for three-dimensional MicroCT and two-dimensional histomorphometric analyses. Bone volume and vital NB percentages were calculated. Immediate after core biopsy, implants having standard dimensions were placed and implant stability quotient values were recorded at baseline and 3 months follow-up. There were no significant differences between groups according to residual bone height, residual bone width, implant dimensions, and implant stability quotient values (baseline and 3 months). According to MicroCT and two-dimensional histomorphometric analyses, the volume of newly formed bone was 57.05% and 52.67%, and 56.5% and 55.08% for xenograft + PTG and xenograft groups, respectively. No statistically significant differences found between groups according to NB percentages and higher Hounsfield unit values were found for xenograft + PTG group. The findings of the current study supports that PTG, which is a porous, permanent nonresorbable bone substitute, may have a beneficial osteoconductive effect on mechanical strength of NB in augmented maxillary sinus.

The building-up of social relationships: behavioural types, social networks and cooperative breeding in a cichlid

PubMed Central

Schürch, Roger; Rothenberger, Susan; Heg, Dik

2010-01-01

Consistent individual differences in behavioural types may not only cause variation in life-history decisions, but may also affect the choice of social partners and sociality in general. Here, we tested whether and how behavioural type influences the establishment of social ties using the cooperatively breeding cichlid, Neolamprologus pulcher. In a habitat saturation experiment with individuals pre-tested for behavioural type, we first analysed whether behavioural type affected the likelihood of settlement (i.e. social status), group sizes, and the types of dominant and subordinate individuals accepted as group members. Corrected for effects of body size and sex, the behavioural type did not affect settlement. However, bold dominant males only accepted smaller females, and grouped with bold subordinates, while shy dominant males accepted larger females than themselves, and grouped with shy subordinates. Second, we analysed the relationships between behavioural type and the aggressiveness or affiliation social network. Behavioural type significantly affected the number and quality of connections within the two networks. We show that behavioural types affect group composition, social networks and status achieved, in interaction with body size. Thus, the interactions within groups may depend not only on age, size and sex, but also on the behavioural type of the individuals involved. PMID:21078660

A critical appraisal of the reporting quality of published randomized controlled trials in the fall injuries.

PubMed

Asghari Jafarabadi, Mohammad; Sadeghi-Bazrgani, Homayoun; Dianat, Iman

2018-06-01

To evaluate the quality of reporting in published randomized controlled trials (RTCs) in the field of fall injuries. The 188 RTCs published between 2001 and 2011, indexed in EMBASE and Medline databases were extracted through searching by appropriate keywords and EMTree classification terms. The evaluation trustworthiness was assured through parallel evaluations of two experts in epidemiology and biostatistics. About 40%-75% of papers had problems in reporting random allocation method, allocation concealment, random allocation implementation, blinding and similarity among groups, intention to treat and balancing benefits and harms. Moreover, at least 10% of papers inappropriately/not reported the design, protocol violations, sample size justification, subgroup/adjusted analyses, presenting flow diagram, drop outs, recruitment time, baseline data, suitable effect size on outcome, ancillary analyses, limitations and generalizability. Considering the shortcomings found and due to the importance of the RCTs for fall injury prevention programmes, their reporting quality should be improved.

Intrinsic dependence of the magnetic properties of CoFe2O4 nanoparticles prepared via chemical methods with addition of chelating agents

NASA Astrophysics Data System (ADS)

Mendonça, E. C.; Tenório, Mayara A.; Mecena, S. G.; Zucolotto, B.; Silva, L. S.; Jesus, C. B. R.; Meneses, C. T.; Duque, J. G. S.

2015-12-01

In this work, the effect of addition of different chelating agents on the magnetic properties of cobalt ferrite nanoparticles produced by the combining of both co-precipitation and hydrothermal methods is reported. The Rietveld analyses of X-ray diffraction patterns reveal that our samples are single phase (space group: Fd-3m) with small average sizes. The weight losses observed in the thermogravimetric measurements together with the M×H curves show that the organic contamination coming from chelating agent decomposition can give rise to misinterpretation of the magnetization measurements. Besides, analyses of the zero-field-cooled (ZFC) and field-cooled (FC) magnetization measurements and the M×H curves measured at room temperature allows us to state that both the average blocking temperature and particles size distribution are sensitive to the kind of chelating agent.

Effects of group-size-floor space allowance during the nursery phase of production on growth, physiology, and hematology in replacement gilts.

PubMed

Callahan, S R; Cross, A J; DeDecker, A E; Lindemann, M D; Estienne, M J

2017-01-01

The objective was to determine effects of nursery group-size-floor space allowance on growth, physiology, and hematology of replacement gilts. A 3 × 3 factorial arrangement of treatments was used wherein gilts classified as large, medium, or small ( = 2537; BW = 5.6 ± 0.6 kg) from 13 groups of weaned pigs were placed in pens of 14, 11, or 8 pigs resulting in floor space allowances of 0.15, 0.19, or 0.27 m/pig, respectively. Pigs were weighed on d 0 (weaning) and d 46 (exit from nursery). The ADG was affected by group-size-floor space allowance × pig size ( = 0.04). Large- and medium-size gilts allowed the most floor space had greater ( < 0.05) ADG than similar size gilts allowed the least floor space but for small size gilts there was no effect ( > 0.05) of group size-floor space allowance. Mortality in the nursery was not affected ( > 0.05) by treatment, size, or treatment × size and overall was approximately 2.1%. Complete blood counts and blood chemistry analyses were performed on samples collected at d 6 and 43 from a subsample of gilts ( = 18/group-size-floor space allowance) within a single group. The concentration ( < 0.01) and percentage ( = 0.03) of reticulocytes was the least and red blood cell distribution width the greatest ( < 0.01) in gilts allowed 0.15 m floor space (effects of treatment). Blood calcium was affected by treatment ( = 0.02) and concentrations for gilts allowed the greatest and intermediate amounts of floor space were greater ( < 0.05) than for gilts allowed the least floor space. Serum concentrations of cortisol were not affected by treatment × day ( = 0.27). Cortisol concentrations increased from d 6 to d 43 in all groups and were affected by day ( < 0.01) but not treatment ( = 0.53). Greater space allowance achieved by placing fewer pigs per pen in the nursery affected blood parameters and resulted in large- and medium-size replacement gilts displaying increased ADG. Further study will determine if these effects influence lifetime reproductive capacity and sow longevity.

Fraternal Birth Order, Family Size, and Male Homosexuality: Meta-Analysis of Studies Spanning 25 Years.

PubMed

Blanchard, Ray

2018-01-01

The fraternal birth order effect is the tendency for older brothers to increase the odds of homosexuality in later-born males. This study compared the strength of the effect in subjects from small versus large families and in homosexual subjects with masculine versus feminine gender identities. Meta-analyses were conducted on 30 homosexual and 30 heterosexual groups from 26 studies, totaling 7140 homosexual and 12,837 heterosexual males. The magnitude of the fraternal birth order effect was measured with a novel variable, the Older Brothers Odds Ratio, computed as (homosexuals' older brothers ÷ homosexuals' other siblings) ÷ (heterosexuals' older brothers ÷ heterosexuals' other siblings), where other siblings = older sisters + younger brothers + younger sisters. An Older Brothers Odds Ratio of 1.00 represents no effect of sexual orientation; values over 1.00 are positive evidence for the fraternal birth order effect. Evidence for the reliability of the effect was consistent. The Older Brothers Odds Ratio was significantly >1.00 in 20 instances, >1.00 although not significantly in nine instances, and nonsignificantly <1.00 in 1 instance. The pooled Older Brothers Odds Ratio for all samples was 1.47, p < .00001. Subgroups analyses showed that the magnitude of the effect was significantly greater in the 12 feminine or transgender homosexual groups than in the other 18 homosexual groups. There was no evidence that the magnitude of the effect differs according to family size.

Locomotor activity measures in the diagnosis of Attention Deficit Hyperactivity Disorder: Meta-analyses and new findings

PubMed Central

Murillo, Lourdes García; Cortese, Samuele; Anderson, David; Martino, Adriana Di; Castellanos, Francisco Xavier

2015-01-01

Introduction Our aim was to assess differences in movement measures in Attention-Deficit/Hyperactivity Disorder (ADHD) vs. typically developing (TD) controls. Methods We performed meta-analyses of published studies on motion measures contrasting ADHD with controls. We also conducted a case-control study with children/adolescents (n=61 TD, n=62 ADHD) and adults (n=30 TD, n=19 ADHD) using the McLean Motion Activity Test, semi-structured diagnostic interviews and the Behavior Rating Inventory of Executive Function and Conners (Parent, Teacher; Self) Rating Scales. Results Meta-analyses revealed medium-to-large effect sizes for actigraph (standardized mean difference [SMD]: 0.64, 95% Confidence interval (CI): 0.43, 0.85) and motion tracking systems (SDM: 0.92, 95% CI: 0.65, 1.20) measures in differentiating individuals with ADHD from controls. Effects sizes were similar in studies of children/adolescents ([SMD]:0.75, 95% CI: 0.50, 1.01) and of adults ([SMD]: 0.73, 95% CI: 0.46, 1.00). In our sample, ADHD groups differed significantly in number of Head Movements (p=0.02 in children; p=0.002 in adults), Displacement (p=0.009/p<0.001), Head Area (p=0.03/p<0.001), Spatial Complexity (p=0.06/p=0.02) and Temporal Scaling (p=0.05/p=0.04). Mean effect sizes were non-significantly larger (d=0.83, 95% CI: 0.20, 1.45) in adults vs. children/adolescents with ADHD (d=0.45, 95% CI: 0.08, 0.82). In the concurrent go/no-go task, reaction time variability was significantly greater in ADHD (p<0.05 in both age groups) than controls. Conclusions Locomotor hyperactivity remains core to the construct of ADHD even in adults. Our results suggest that objective locomotion measures may be particularly useful in evaluating adults with possible ADHD. PMID:25770940

50 years of rational-emotive and cognitive-behavioral therapy: A systematic review and meta-analysis.

PubMed

David, Daniel; Cotet, Carmen; Matu, Silviu; Mogoase, Cristina; Stefan, Simona

2018-03-01

Rational emotive behavior therapy (REBT), introduced by Albert Ellis in the late 1950s, is one of the main pillars of cognitive-behavioral therapy. Existing reviews on REBT are overdue by 10 years or more. We aimed to summarize the effectiveness and efficacy of REBT since its beginnings and investigate the alleged mechanisms of change. Systematic search identified 84 articles, out of which 68 provided data for between-group analyses and 39 for within-group analyses. We found a medium effect size of REBT compared to other interventions on outcomes (d = 0.58) and on irrational beliefs (d = 0.70), at posttest. For the within-group analyses, we obtained medium effects for both outcomes (d = 0.56) and irrational beliefs (d = 0.61). Several significant moderators emerged. REBT is a sound psychological intervention. Directions for future studies are outlined, stemming from the limitations of existing ones. © 2017 The Authors. Journal of Clinical Psychology published by Wiley Periodicals, Inc.

Thermal modeling and analysis of structurally complex spacecraft using the IDEAS system

NASA Technical Reports Server (NTRS)

Garrett, L. B.

1983-01-01

Large antenna satellites of unprecedented sizes are needed for a number of applications. Antenna diameters on the order of 50 meters and upward are required. Such antennas involve the use of large expanses of lattice structures with hundreds or thousands of individual connecting members. In connection with the design of such structures, the consideration of thermal effects represents a crucial factor. Software capabilities have emerged which are coded to include major first order thermal effects and to purposely ignore, in the interest of computational efficiency, the secondary effects. The Interactive Design and Evaluation of Advanced Spacecraft (IDEAS) is one such system. It has been developed for an employment in connection with thermal-structural interaction analyses related to the design of large structurally complex classes of future spacecraft. An IDEAS overview is presented. Attention is given to a typical antenna analysis using IDEAS, the thermal and loading analyses of a tetrahedral truss spacecraft, and ecliptic and polar orbit analyses.

Effects of artificial settlement plate materials and methods of deployment on the sessile epibenthic community development in a tropical environment

NASA Astrophysics Data System (ADS)

Field, S. N.; Glassom, D.; Bythell, J.

2007-06-01

The choice of substrata and the methods of deployment in analyses of settlement in benthic communities are often driven by the cost of materials and their local availability, and comparisons are often made between studies using different methodologies. The effects of varying artificial substratum, size of replicates and method of deployment were determined on a shallow reef in Eilat, Israel, while the effect of size of replicates was also investigated on a shallow reef in Sharm El Sheikh, Egypt. When statistical power was high enough, that is, when sufficient numbers of settlers were recorded, significant differences were found between materials used, tile size and methods of deployment. Significant differences were detected in total coral settlement rates and for the two dominant taxonomic groups, acroporids and pocilloporids. Standardisation of tile materials, dimensions, and method of deployment is needed for comparison between coral and other epibiont settlement studies. However, a greater understanding of the effects of these experimental variables on settlement processes may enable retrospective comparisons between studies utilising a range of materials and methods.

A general theory of effect size, and its consequences for defining the benchmark response (BMR) for continuous endpoints.

PubMed

Slob, Wout

2017-04-01

A general theory on effect size for continuous data predicts a relationship between maximum response and within-group variation of biological parameters, which is empirically confirmed by results from dose-response analyses of 27 different biological parameters. The theory shows how effect sizes observed in distinct biological parameters can be compared and provides a basis for a generic definition of small, intermediate and large effects. While the theory is useful for experimental science in general, it has specific consequences for risk assessment: it solves the current debate on the appropriate metric for the Benchmark response in continuous data. The theory shows that scaling the BMR expressed as a percent change in means to the maximum response (in the way specified) automatically takes "natural variability" into account. Thus, the theory supports the underlying rationale of the BMR 1 SD. For various reasons, it is, however, recommended to use a BMR in terms of a percent change that is scaled to maximum response and/or within group variation (averaged over studies), as a single harmonized approach.

MicroCT and microMRI imaging of a prenatal mouse model of increased brain size

NASA Astrophysics Data System (ADS)

López, Elisabeth K. N.; Stock, Stuart R.; Taketo, Makoto M.; Chenn, Anjen; Ravosa, Matthew J.

2008-08-01

There are surprisingly few experimental models of neural growth and cranial integration. This and the dearth of information regarding fetal brain development detract from a mechanistic understanding of cranial integration and its relevance to the patterning of skull form, specifically the role of encephalization on basicranial flexion. To address this shortcoming, our research uses transgenic mice expressing a stabilized form of β-catenin to isolate the effects of relative brain size on craniofacial development. These mice develop highly enlarged brains due to an increase in neural precursors, and differences between transgenic and wild-type mice are predicted to result solely from variation in brain size. Comparisons of wild-type and transgenic mice at several prenatal ages were performed using microCT (Scanco Medical MicroCT 40) and microMRI (Avance 600 WB MR spectrometer). Statistical analyses show that the larger brain of the transgenic mice is associated with a larger neurocranium and an altered basicranial morphology. However, body size and postcranial ossification do not seem to be affected by the transgene. Comparisons of the rate of postcranial and cranial ossification using microCT also point to an unexpected effect of neural growth on skull development: increased fetal encephalization may result in a compensatory decrease in the level of cranial ossification. Therefore, if other life history factors are held constant, the ontogeny of a metabolically costly structure such as a brain may occur at the expense of other cranial structures. These analyses indicate the benefits of a multifactorial approach to cranial integration using a mouse model.

Estimated abundance of wild burros surveyed on Bureau of Land Management Lands in 2014

USGS Publications Warehouse

Griffin, Paul C.

2015-01-01

The Bureau of Land Management (BLM) requires accurate estimates of the numbers of wild horses (Equus ferus caballus) and burros (Equus asinus) living on the lands it manages. For over ten years, BLM in Arizona has used the simultaneous double-observer method of recording wild burros during aerial surveys and has reported population estimates for those surveys that come from two formulations of a Lincoln-Petersen type of analysis (Graham and Bell, 1989). In this report, I provide those same two types of burro population analysis for 2014 aerial survey data from six herd management areas (HMAs) in Arizona, California, Nevada, and Utah. I also provide burro population estimates based on a different form of simultaneous double-observer analysis, now in widespread use for wild horse surveys that takes into account the potential effects on detection probability of sighting covariates including group size, distance, vegetative cover, and other factors (Huggins, 1989, 1991). The true number of burros present in the six areas surveyed was not known, so population estimates made with these three types of analyses cannot be directly tested for accuracy in this report. I discuss theoretical reasons why the Huggins (1989, 1991) type of analysis should provide less biased estimates of population size than the Lincoln-Petersen analyses and why estimates from all forms of double-observer analyses are likely to be lower than the true number of animals present in the surveyed areas. I note reasons why I suggest using burro observations made at all available distances in analyses, not only those within 200 meters of the flight path. For all analytical methods, small sample sizes of observed groups can be problematic, but that sample size can be increased over time for Huggins (1989, 1991) analyses by pooling observations. I note ways by which burro population estimates could be tested for accuracy when there are radio-collared animals in the population or when there are simultaneous double-observer surveys before and after a burro gather and removal.

Magnitude of cognitive dysfunction in adults with type 2 diabetes: a meta-analysis of six cognitive domains and the most frequently reported neuropsychological tests within domains.

PubMed

Palta, Priya; Schneider, Andrea L C; Biessels, Geert Jan; Touradji, Pegah; Hill-Briggs, Felicia

2014-03-01

The objectives were to conduct a meta-analysis in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) standards to determine effect sizes (Cohen's d) for cognitive dysfunction in adults with type 2 diabetes, relative to nondiabetic controls, and to obtain effect sizes for the most commonly reported neuropsychological tests within domains. Twenty-four studies, totaling 26,137 patients (n = 3351 with diabetes), met study inclusion criteria. Small to moderate effect sizes were obtained for five of six domains: motor function (3 studies, n = 2374; d = -0.36), executive function (12 studies, n = 1784; d = -0.33), processing speed (16 studies, n = 3076; d = -0.33), verbal memory (15 studies, n = 4,608; d = -0.28), and visual memory (6 studies, n = 1754; d = -0.26). Effect size was smallest for attention/concentration (14 studies, n = 23,143; d = -0.19). The following tests demonstrated the most notable performance decrements in diabetes samples: Grooved Pegboard (dominant hand) (d = -0.60), Rey Auditory Verbal Learning Test (immediate) (d = -0.40), Trails B (d = -0.39), Rey-Osterreith Complex Figure (delayed) (d = -0.38), Trails A (d = -0.34), and Stroop Part I (d = -0.28). This study provides effect sizes to power future epidemiological and clinical diabetes research studies examining cognitive function and to help inform the selection of neuropsychological tests.

Limited genomic consequences of mixed mating in the recently derived sister species pair, Collinsia concolor and Collinsia parryi.

PubMed

Salcedo, A; Kalisz, S; Wright, S I

2014-07-01

Highly selfing species often show reduced effective population sizes and reduced selection efficacy. Whether mixed mating species, which produce both self and outcross progeny, show similar patterns of diversity and selection remains less clear. Examination of patterns of molecular evolution and levels of diversity in species with mixed mating systems can be particularly useful for investigating the relative importance of linked selection and demographic effects on diversity and the efficacy of selection, as the effects of linked selection should be minimal in mixed mating populations, although severe bottlenecks tied to founder events could still be frequent. To begin to address this gap, we assembled and analysed the transcriptomes of individuals from a recently diverged mixed mating sister species pair in the self-compatible genus, Collinsia. The de novo assembly of 52 and 37 Mbp C. concolor and C. parryi transcriptomes resulted in ~40 000 and ~55 000 contigs, respectively, both with an average contig size ~945. We observed a high ratio of shared polymorphisms to fixed differences in the species pair and minimal differences between species in the ratio of synonymous to replacement substitutions or codon usage bias implying comparable effective population sizes throughout species divergence. Our results suggest that differences in effective population size and selection efficacy in mixed mating taxa shortly after their divergence may be minimal and are likely influenced by fluctuating mating systems and population sizes. © 2014 The Authors. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.

Celebrity suicides and their differential influence on suicides in the general population: a national population-based study in Korea.

PubMed

Myung, Woojae; Won, Hong-Hee; Fava, Maurizio; Mischoulon, David; Yeung, Albert; Lee, Dongsoo; Kim, Doh Kwan; Jeon, Hong Jin

2015-04-01

Although evidence suggests that there is an increase in suicide rates in the general population following celebrity suicide, the rates are heterogeneous across celebrities and countries. It is unclear which is the more vulnerable population according to the effect sizes of celebrity suicides to general population. All suicide victims in the general population verified by the Korea National Statistical Office and suicides of celebrity in South Korea were included for 7 years from 2005 to 2011. Effect sizes were estimated by comparing rates of suicide in the population one month before and after each celebrity suicide. The associations between suicide victims and celebrities were examined. Among 94,845 suicide victims, 17,209 completed suicide within one month after 13 celebrity suicides. Multivariate logistic regression analyses revealed that suicide victims who died after celebrity suicide were significantly likely to be of age 20-39, female, and to die by hanging. These qualities were more strongly associated among those who followed celebrity suicide with intermediate and high effect sizes than lower. Younger suicide victims were significantly associated with higher effect size, female gender, white collar employment, unmarried status, higher education, death by hanging, and night-time death. Characteristics of celebrities were significantly associated with those of general population in hanging method and gender. Individuals who commit suicide after a celebrity suicide are likely to be younger, female, and prefer hanging as method of suicide, which are more strongly associated in higher effect sizes of celebrity suicide.

Calibrating the Ordovician Radiation of marine life: implications for Phanerozoic diversity trends

NASA Technical Reports Server (NTRS)

Miller, A. I.; Foote, M.

1996-01-01

It has long been suspected that trends in global marine biodiversity calibrated for the Phanerozoic may be affected by sampling problems. However, this possibility has not been evaluated definitively, and raw diversity trends are generally accepted at face value in macroevolutionary investigations. Here, we analyze a global-scale sample of fossil occurrences that allows us to determine directly the effects of sample size on the calibration of what is generally thought to be among the most significant global biodiversity increases in the history of life: the Ordovician Radiation. Utilizing a composite database that includes trilobites, brachiopods, and three classes of molluscs, we conduct rarefaction analyses to demonstrate that the diversification trajectory for the Radiation was considerably different than suggested by raw diversity time-series. Our analyses suggest that a substantial portion of the increase recognized in raw diversity depictions for the last three Ordovician epochs (the Llandeilian, Caradocian, and Ashgillian) is a consequence of increased sample size of the preserved and catalogued fossil record. We also use biometric data for a global sample of Ordovician trilobites, along with methods of measuring morphological diversity that are not biased by sample size, to show that morphological diversification in this major clade had leveled off by the Llanvirnian. The discordance between raw diversity depictions and more robust taxonomic and morphological diversity metrics suggests that sampling effects may strongly influence our perception of biodiversity trends throughout the Phanerozoic.

Morphological change to birds over 120 years is not explained by thermal adaptation to climate change.

PubMed

Salewski, Volker; Siebenrock, Karl-Heinz; Hochachka, Wesley M; Woog, Friederike; Fiedler, Wolfgang

2014-01-01

Changes in morphology have been postulated as one of the responses of animals to global warming, with increasing ambient temperatures leading to decreasing body size. However, the results of previous studies are inconsistent. Problems related to the analyses of trends in body size may be related to the short-term nature of data sets, to the selection of surrogates for body size, to the appropriate models for data analyses, and to the interpretation as morphology may change in response to ecological drivers other than climate and irrespective of size. Using generalized additive models, we analysed trends in three morphological traits of 4529 specimens of eleven bird species collected between 1889 and 2010 in southern Germany and adjacent areas. Changes and trends in morphology over time were not consistent when all species and traits were considered. Six of the eleven species displayed a significant association of tarsus length with time but the direction of the association varied. Wing length decreased in the majority of species but there were few significant trends in wing pointedness. Few of the traits were significantly associated with mean ambient temperatures. We argue that although there are significant changes in morphology over time there is no consistent trend for decreasing body size and therefore no support for the hypothesis of decreasing body size because of climate change. Non-consistent trends of change in surrogates for size within species indicate that fluctuations are influenced by factors other than temperature, and that not all surrogates may represent size appropriately. Future analyses should carefully select measures of body size and consider alternative hypotheses for change.

The relationship of cranial, orbital and nasal cavity size with the morphology of the supraorbital region in modern Homo sapiens.

PubMed

Nowaczewska, Wioletta; Łapicka, Urszula; Cieślik, Agata; Biecek, Przemysław

2017-09-01

Morphological variation of the supraorbital region (SR) in human crania has been investigated and its potential sources suggested, along with the importance of the size of the facial skeleton, neurocranium, and orbit for the formation of this region. However, previous studies have not indicated whether facial size exhibits a stronger association with SR robusticity than neurocranial size or sex; moreover, the association between orbital volume and SR robusticity has been analysed only in non-human primate skulls. In this study we investigate whether the size of the facial skeleton, neurocranium, two measures of relative orbital size (orbital volume and estimated orbital aperture area), the relative size of the nasal cavity, and the relative estimated area of the anterior nasal cavity opening are related to SR robusticity; we also examine which of these analysed relationships is strongest, as well as independent of the influence of the other traits, in a geographically diverse modern human cranial sample. The results of Spearman's rank and partial rank correlations (encompassing models including or excluding sex and geographic origin) show a relationship between most of the above-mentioned variables and SR robusticity, with the exception of the estimated relative area of the orbital opening (in the case of the results of Spearman's rank correlations) and the traits of the nasal cavity. Of all the analysed traits, sex appears to be the most important for the formation of SR robusticity and, of two measures of cranial size, neurocranial size was the most significant. The strong relationship between SR robusticity and relative orbital volume was observed in models without the geographic origin factor. The results concerning analysed models suggest the influence of this factor on this relationship; however, to explain this influence, further studies are needed.

Research review: the role of diet in the treatment of attention-deficit/hyperactivity disorder--an appraisal of the evidence on efficacy and recommendations on the design of future studies.

PubMed

Stevenson, Jim; Buitelaar, Jan; Cortese, Samuele; Ferrin, Maite; Konofal, Eric; Lecendreux, Michel; Simonoff, Emily; Wong, Ian C K; Sonuga-Barke, Edmund

2014-05-01

The efficacy of three dietary treatments for ADHD has been repeatedly tested in randomized controlled trials (RCTs). These interventions are restricted elimination diets (RED), artificial food colour elimination (AFCE) and supplementation with free fatty acids (SFFA). There have been three systematic reviews and associated meta-analyses of the RCTs for each of these treatments. The aim of this review is to critically appraise the studies on the dietary treatments of ADHD, to compare the various meta-analyses of their efficacy that have been published and to identify where the design of such RCTs could be improved and where further investigations are needed. The meta-analyses differ in the inclusion and exclusion criteria applied to potentially eligible studies. The range of average effect sizes in standard deviation units is RED (0.29-1.2), AFCE (0.18-0.42) and SFFA (0.17-0.31). The methodology of many of the trials on which the meta-analyses are based is weak. Nevertheless, there is evidence from well-conducted studies for a small effect of SFFA. Restricted elimination diets may be beneficial, but large-scale studies are needed on unselected children, using blind assessment and including assessment of long-term outcome. Artificial food colour elimination is a potentially valuable treatment but its effect size remains uncertain, as does the type of child for whom it is likely to be efficacious. There are additional dietary supplements that have been used with children with ADHD. A systematic search identified 11 RCTs that investigated the effects of these food supplements. Despite positive results for some individual trials, more studies are required before conclusions can be reached on the value in reducing ADHD symptoms of any of these additional supplements. © 2014 The Authors. Journal of Child Psychology and Psychiatry. © 2014 Association for Child and Adolescent Mental Health.

Meta-analysis of organizational skills interventions for children and adolescents with Attention-Deficit/Hyperactivity Disorder.

PubMed

Bikic, Aida; Reichow, Brian; McCauley, Spencer A; Ibrahim, Karim; Sukhodolsky, Denis G

2017-03-01

In addition to problems with attention and hyperactivity, children with ADHD present with poor organizational skills required for managing time and materials in academic projects. Organizational skills training (OST) has been increasingly used to address these deficits. We conducted a systematic review and meta-analysis of OST in children with ADHD. The objective of this study was to systematically review the evidence of the effects of OST for children with ADHD for organizational skills, attention, and academic performance. We searched 3 electronic databases to locate randomized controlled trials published in English in peer-reviewed journals comparing OST with parent education, treatment-as-usual, or waitlist control conditions. Standardized mean difference effect sizes from the studies were statistically combined using a random-effects meta-analyses across six outcomes: teacher- and parent-rated organizational skills, teacher- and parent-rated inattention, teacher-rated academic performance, and Grade Point Average (GPA). Risk of bias was assessed for randomization, allocation concealment, blinding of participants and treatment personnel, blinding of outcome assessors, incomplete outcome data, and selective outcome reporting. Twelve studies involving 1054 children (576 treatment, 478 control) were included in the meta-analyses. Weighted mean effect sizes for teacher- and parent-rated outcome measures of organizational skills were g=0.54 (95% CI 0.17 to 0.91) and g=0.83 (95% CI 0.32 to 1.34), respectively. Weighted mean effect sizes of teacher- and parent-rated symptoms of inattention were g=0.26 (95% CI 0.01 to 0.52) and g=0.56 (95% CI 0.38 to 0.74), respectively. Weighted standardized mean effect size for teacher-rated academic performance and GPA were g=0.33 (95% CI 0.14 to 0.51) and g=0.29 (95% CI 0.07 to 0.51), respectively. OST leads to moderate improvements in organizational skills of children with ADHD as rated by teachers and large improvements as rated by parents. More modest improvements were observed on the ratings of symptoms of inattention and academic performance. PROSPERO (CRD42015019261). Copyright © 2016 Elsevier Ltd. All rights reserved.

Cognitive Behavioral Therapy for Management of Dyspnea: A Pilot Study.

PubMed

Williams, Marie T; Cafarella, Paul; Paquet, Catherine; Frith, Peter

2015-09-01

In patients with COPD, psychological interventions usually target generalized anxiety and depression rather than the sensation of breathlessness. The objectives of this pilot study were to develop and implement a cognitive behavioral therapy (CBT) program specific to the perceptual experience of breathlessness, identify practical issues in the study protocol, and estimate beneficial effects of combining the CBT program with comprehensive pulmonary rehabilitation. The CBT program for the sensation of breathlessness (Breathing: Recognize sensations, Explore thoughts and beliefs, Validate thoughts as useful or harmful, Evolve and change behavior [BREVE]) was developed as a sequential series of 8 modules enabling it to be embedded within an 8-week comprehensive pulmonary rehabilitation program. When appropriate, outcomes from the pilot group (comprehensive pulmonary rehabilitation program + BREVE) were compared with those from a retrospective control group (comprehensive pulmonary rehabilitation program only). Outcomes included feedback provided by pilot study subjects, sensation of breathlessness (volunteered and endorsed descriptors of breathlessness), 6-min walk distance (6MWD), and St George Respiratory Questionnaire (SGRQ) total score. Within-group analyses were undertaken for descriptors of breathlessness (the McNemar test), whereas between-group analyses (repeated-measures analysis of variance, effect-size comparison) were conducted for the 6MWD and SGRQ total score. Pilot (n = 11) and control (n = 58) groups were not significantly different at baseline. Feedback indicated that the program structure and content were positively received. No significant changes were evident for the sensation of breathlessness or the SGRQ score (< 4 points). The 6MWD improved significantly in both groups, with the pilot group demonstrating greater gains compared with the control group (mean change of 57 m and effect size of 0.73 vs mean change of 27 m and effect size of 0.23; between groups, P = .03, effect size of 0.69). The CBT program for the perceptual experience of breathlessness was feasible and well accepted by subjects, although the protocol raised a number of methodological limitations warranting modification. A larger randomized controlled trial is needed to determine the effectiveness and longer-term outcomes. Copyright © 2015 by Daedalus Enterprises.

The consequences of perceived discrimination for psychological well-being: a meta-analytic review.

PubMed

Schmitt, Michael T; Branscombe, Nyla R; Postmes, Tom; Garcia, Amber

2014-07-01

In 2 meta-analyses, we examined the relationship between perceived discrimination and psychological well-being and tested a number of moderators of that relationship. In Meta-Analysis 1 (328 independent effect sizes, N = 144,246), we examined correlational data measuring both perceived discrimination and psychological well-being (e.g., self-esteem, depression, anxiety, psychological distress, life satisfaction). Using a random-effects model, the mean weighted effect size was significantly negative, indicating harm (r = -.23). Effect sizes were larger for disadvantaged groups (r = -.24) compared to advantaged groups (r = -.10), larger for children compared to adults, larger for perceptions of personal discrimination compared to group discrimination, and weaker for racism and sexism compared to other stigmas. The negative relationship was significant across different operationalizations of well-being but was somewhat weaker for positive outcomes (e.g., self-esteem, positive affect) than for negative outcomes (e.g., depression, anxiety, negative affect). Importantly, the effect size was significantly negative even in longitudinal studies that controlled for prior levels of well-being (r = -.15). In Meta-Analysis 2 (54 independent effect sizes, N = 2,640), we examined experimental data from studies manipulating perceptions of discrimination and measuring well-being. We found that the effect of discrimination on well-being was significantly negative for studies that manipulated general perceptions of discrimination (d = -.25), but effects did not differ from 0 when attributions to discrimination for a specific negative event were compared to personal attributions (d = .06). Overall, results support the idea that the pervasiveness of perceived discrimination is fundamental to its harmful effects on psychological well-being. PsycINFO Database Record (c) 2014 APA, all rights reserved.

The Influence of Age and Sex on Genetic Associations with Adult Body Size and Shape: A Large-Scale Genome-Wide Interaction Study.

PubMed

Winkler, Thomas W; Justice, Anne E; Graff, Mariaelisa; Barata, Llilda; Feitosa, Mary F; Chu, Su; Czajkowski, Jacek; Esko, Tõnu; Fall, Tove; Kilpeläinen, Tuomas O; Lu, Yingchang; Mägi, Reedik; Mihailov, Evelin; Pers, Tune H; Rüeger, Sina; Teumer, Alexander; Ehret, Georg B; Ferreira, Teresa; Heard-Costa, Nancy L; Karjalainen, Juha; Lagou, Vasiliki; Mahajan, Anubha; Neinast, Michael D; Prokopenko, Inga; Simino, Jeannette; Teslovich, Tanya M; Jansen, Rick; Westra, Harm-Jan; White, Charles C; Absher, Devin; Ahluwalia, Tarunveer S; Ahmad, Shafqat; Albrecht, Eva; Alves, Alexessander Couto; Bragg-Gresham, Jennifer L; de Craen, Anton J M; Bis, Joshua C; Bonnefond, Amélie; Boucher, Gabrielle; Cadby, Gemma; Cheng, Yu-Ching; Chiang, Charleston W K; Delgado, Graciela; Demirkan, Ayse; Dueker, Nicole; Eklund, Niina; Eiriksdottir, Gudny; Eriksson, Joel; Feenstra, Bjarke; Fischer, Krista; Frau, Francesca; Galesloot, Tessel E; Geller, Frank; Goel, Anuj; Gorski, Mathias; Grammer, Tanja B; Gustafsson, Stefan; Haitjema, Saskia; Hottenga, Jouke-Jan; Huffman, Jennifer E; Jackson, Anne U; Jacobs, Kevin B; Johansson, Åsa; Kaakinen, Marika; Kleber, Marcus E; Lahti, Jari; Mateo Leach, Irene; Lehne, Benjamin; Liu, Youfang; Lo, Ken Sin; Lorentzon, Mattias; Luan, Jian'an; Madden, Pamela A F; Mangino, Massimo; McKnight, Barbara; Medina-Gomez, Carolina; Monda, Keri L; Montasser, May E; Müller, Gabriele; Müller-Nurasyid, Martina; Nolte, Ilja M; Panoutsopoulou, Kalliope; Pascoe, Laura; Paternoster, Lavinia; Rayner, Nigel W; Renström, Frida; Rizzi, Federica; Rose, Lynda M; Ryan, Kathy A; Salo, Perttu; Sanna, Serena; Scharnagl, Hubert; Shi, Jianxin; Smith, Albert Vernon; Southam, Lorraine; Stančáková, Alena; Steinthorsdottir, Valgerdur; Strawbridge, Rona J; Sung, Yun Ju; Tachmazidou, Ioanna; Tanaka, Toshiko; Thorleifsson, Gudmar; Trompet, Stella; Pervjakova, Natalia; Tyrer, Jonathan P; Vandenput, Liesbeth; van der Laan, Sander W; van der Velde, Nathalie; van Setten, Jessica; van Vliet-Ostaptchouk, Jana V; Verweij, Niek; Vlachopoulou, Efthymia; Waite, Lindsay L; Wang, Sophie R; Wang, Zhaoming; Wild, Sarah H; Willenborg, Christina; Wilson, James F; Wong, Andrew; Yang, Jian; Yengo, Loïc; Yerges-Armstrong, Laura M; Yu, Lei; Zhang, Weihua; Zhao, Jing Hua; Andersson, Ehm A; Bakker, Stephan J L; Baldassarre, Damiano; Banasik, Karina; Barcella, Matteo; Barlassina, Cristina; Bellis, Claire; Benaglio, Paola; Blangero, John; Blüher, Matthias; Bonnet, Fabrice; Bonnycastle, Lori L; Boyd, Heather A; Bruinenberg, Marcel; Buchman, Aron S; Campbell, Harry; Chen, Yii-Der Ida; Chines, Peter S; Claudi-Boehm, Simone; Cole, John; Collins, Francis S; de Geus, Eco J C; de Groot, Lisette C P G M; Dimitriou, Maria; Duan, Jubao; Enroth, Stefan; Eury, Elodie; Farmaki, Aliki-Eleni; Forouhi, Nita G; Friedrich, Nele; Gejman, Pablo V; Gigante, Bruna; Glorioso, Nicola; Go, Alan S; Gottesman, Omri; Gräßler, Jürgen; Grallert, Harald; Grarup, Niels; Gu, Yu-Mei; Broer, Linda; Ham, Annelies C; Hansen, Torben; Harris, Tamara B; Hartman, Catharina A; Hassinen, Maija; Hastie, Nicholas; Hattersley, Andrew T; Heath, Andrew C; Henders, Anjali K; Hernandez, Dena; Hillege, Hans; Holmen, Oddgeir; Hovingh, Kees G; Hui, Jennie; Husemoen, Lise L; Hutri-Kähönen, Nina; Hysi, Pirro G; Illig, Thomas; De Jager, Philip L; Jalilzadeh, Shapour; Jørgensen, Torben; Jukema, J Wouter; Juonala, Markus; Kanoni, Stavroula; Karaleftheri, Maria; Khaw, Kay Tee; Kinnunen, Leena; Kittner, Steven J; Koenig, Wolfgang; Kolcic, Ivana; Kovacs, Peter; Krarup, Nikolaj T; Kratzer, Wolfgang; Krüger, Janine; Kuh, Diana; Kumari, Meena; Kyriakou, Theodosios; Langenberg, Claudia; Lannfelt, Lars; Lanzani, Chiara; Lotay, Vaneet; Launer, Lenore J; Leander, Karin; Lindström, Jaana; Linneberg, Allan; Liu, Yan-Ping; Lobbens, Stéphane; Luben, Robert; Lyssenko, Valeriya; Männistö, Satu; Magnusson, Patrik K; McArdle, Wendy L; Menni, Cristina; Merger, Sigrun; Milani, Lili; Montgomery, Grant W; Morris, Andrew P; Narisu, Narisu; Nelis, Mari; Ong, Ken K; Palotie, Aarno; Pérusse, Louis; Pichler, Irene; Pilia, Maria G; Pouta, Anneli; Rheinberger, Myriam; Ribel-Madsen, Rasmus; Richards, Marcus; Rice, Kenneth M; Rice, Treva K; Rivolta, Carlo; Salomaa, Veikko; Sanders, Alan R; Sarzynski, Mark A; Scholtens, Salome; Scott, Robert A; Scott, William R; Sebert, Sylvain; Sengupta, Sebanti; Sennblad, Bengt; Seufferlein, Thomas; Silveira, Angela; Slagboom, P Eline; Smit, Jan H; Sparsø, Thomas H; Stirrups, Kathleen; Stolk, Ronald P; Stringham, Heather M; Swertz, Morris A; Swift, Amy J; Syvänen, Ann-Christine; Tan, Sian-Tsung; Thorand, Barbara; Tönjes, Anke; Tremblay, Angelo; Tsafantakis, Emmanouil; van der Most, Peter J; Völker, Uwe; Vohl, Marie-Claude; Vonk, Judith M; Waldenberger, Melanie; Walker, Ryan W; Wennauer, Roman; Widén, Elisabeth; Willemsen, Gonneke; Wilsgaard, Tom; Wright, Alan F; Zillikens, M Carola; van Dijk, Suzanne C; van Schoor, Natasja M; Asselbergs, Folkert W; de Bakker, Paul I W; Beckmann, Jacques S; Beilby, John; Bennett, David A; Bergman, Richard N; Bergmann, Sven; Böger, Carsten A; Boehm, Bernhard O; Boerwinkle, Eric; Boomsma, Dorret I; Bornstein, Stefan R; Bottinger, Erwin P; Bouchard, Claude; Chambers, John C; Chanock, Stephen J; Chasman, Daniel I; Cucca, Francesco; Cusi, Daniele; Dedoussis, George; Erdmann, Jeanette; Eriksson, Johan G; Evans, Denis A; de Faire, Ulf; Farrall, Martin; Ferrucci, Luigi; Ford, Ian; Franke, Lude; Franks, Paul W; Froguel, Philippe; Gansevoort, Ron T; Gieger, Christian; Grönberg, Henrik; Gudnason, Vilmundur; Gyllensten, Ulf; Hall, Per; Hamsten, Anders; van der Harst, Pim; Hayward, Caroline; Heliövaara, Markku; Hengstenberg, Christian; Hicks, Andrew A; Hingorani, Aroon; Hofman, Albert; Hu, Frank; Huikuri, Heikki V; Hveem, Kristian; James, Alan L; Jordan, Joanne M; Jula, Antti; Kähönen, Mika; Kajantie, Eero; Kathiresan, Sekar; Kiemeney, Lambertus A L M; Kivimaki, Mika; Knekt, Paul B; Koistinen, Heikki A; Kooner, Jaspal S; Koskinen, Seppo; Kuusisto, Johanna; Maerz, Winfried; Martin, Nicholas G; Laakso, Markku; Lakka, Timo A; Lehtimäki, Terho; Lettre, Guillaume; Levinson, Douglas F; Lind, Lars; Lokki, Marja-Liisa; Mäntyselkä, Pekka; Melbye, Mads; Metspalu, Andres; Mitchell, Braxton D; Moll, Frans L; Murray, Jeffrey C; Musk, Arthur W; Nieminen, Markku S; Njølstad, Inger; Ohlsson, Claes; Oldehinkel, Albertine J; Oostra, Ben A; Palmer, Lyle J; Pankow, James S; Pasterkamp, Gerard; Pedersen, Nancy L; Pedersen, Oluf; Penninx, Brenda W; Perola, Markus; Peters, Annette; Polašek, Ozren; Pramstaller, Peter P; Psaty, Bruce M; Qi, Lu; Quertermous, Thomas; Raitakari, Olli T; Rankinen, Tuomo; Rauramaa, Rainer; Ridker, Paul M; Rioux, John D; Rivadeneira, Fernando; Rotter, Jerome I; Rudan, Igor; den Ruijter, Hester M; Saltevo, Juha; Sattar, Naveed; Schunkert, Heribert; Schwarz, Peter E H; Shuldiner, Alan R; Sinisalo, Juha; Snieder, Harold; Sørensen, Thorkild I A; Spector, Tim D; Staessen, Jan A; Stefania, Bandinelli; Thorsteinsdottir, Unnur; Stumvoll, Michael; Tardif, Jean-Claude; Tremoli, Elena; Tuomilehto, Jaakko; Uitterlinden, André G; Uusitupa, Matti; Verbeek, André L M; Vermeulen, Sita H; Viikari, Jorma S; Vitart, Veronique; Völzke, Henry; Vollenweider, Peter; Waeber, Gérard; Walker, Mark; Wallaschofski, Henri; Wareham, Nicholas J; Watkins, Hugh; Zeggini, Eleftheria; Chakravarti, Aravinda; Clegg, Deborah J; Cupples, L Adrienne; Gordon-Larsen, Penny; Jaquish, Cashell E; Rao, D C; Abecasis, Goncalo R; Assimes, Themistocles L; Barroso, Inês; Berndt, Sonja I; Boehnke, Michael; Deloukas, Panos; Fox, Caroline S; Groop, Leif C; Hunter, David J; Ingelsson, Erik; Kaplan, Robert C; McCarthy, Mark I; Mohlke, Karen L; O'Connell, Jeffrey R; Schlessinger, David; Strachan, David P; Stefansson, Kari; van Duijn, Cornelia M; Hirschhorn, Joel N; Lindgren, Cecilia M; Heid, Iris M; North, Kari E; Borecki, Ingrid B; Kutalik, Zoltán; Loos, Ruth J F

2015-10-01

Genome-wide association studies (GWAS) have identified more than 100 genetic variants contributing to BMI, a measure of body size, or waist-to-hip ratio (adjusted for BMI, WHRadjBMI), a measure of body shape. Body size and shape change as people grow older and these changes differ substantially between men and women. To systematically screen for age- and/or sex-specific effects of genetic variants on BMI and WHRadjBMI, we performed meta-analyses of 114 studies (up to 320,485 individuals of European descent) with genome-wide chip and/or Metabochip data by the Genetic Investigation of Anthropometric Traits (GIANT) Consortium. Each study tested the association of up to ~2.8M SNPs with BMI and WHRadjBMI in four strata (men ≤50y, men >50y, women ≤50y, women >50y) and summary statistics were combined in stratum-specific meta-analyses. We then screened for variants that showed age-specific effects (G x AGE), sex-specific effects (G x SEX) or age-specific effects that differed between men and women (G x AGE x SEX). For BMI, we identified 15 loci (11 previously established for main effects, four novel) that showed significant (FDR<5%) age-specific effects, of which 11 had larger effects in younger (<50y) than in older adults (≥50y). No sex-dependent effects were identified for BMI. For WHRadjBMI, we identified 44 loci (27 previously established for main effects, 17 novel) with sex-specific effects, of which 28 showed larger effects in women than in men, five showed larger effects in men than in women, and 11 showed opposite effects between sexes. No age-dependent effects were identified for WHRadjBMI. This is the first genome-wide interaction meta-analysis to report convincing evidence of age-dependent genetic effects on BMI. In addition, we confirm the sex-specificity of genetic effects on WHRadjBMI. These results may provide further insights into the biology that underlies weight change with age or the sexually dimorphism of body shape.

The Influence of Age and Sex on Genetic Associations with Adult Body Size and Shape: A Large-Scale Genome-Wide Interaction Study

PubMed Central

Feitosa, Mary F.; Chu, Su; Czajkowski, Jacek; Esko, Tõnu; Fall, Tove; Kilpeläinen, Tuomas O.; Lu, Yingchang; Mägi, Reedik; Mihailov, Evelin; Pers, Tune H.; Rüeger, Sina; Teumer, Alexander; Ehret, Georg B.; Ferreira, Teresa; Heard-Costa, Nancy L.; Karjalainen, Juha; Lagou, Vasiliki; Mahajan, Anubha; Neinast, Michael D.; Prokopenko, Inga; Simino, Jeannette; Teslovich, Tanya M.; Jansen, Rick; Westra, Harm-Jan; White, Charles C.; Absher, Devin; Ahluwalia, Tarunveer S.; Ahmad, Shafqat; Albrecht, Eva; Alves, Alexessander Couto; Bragg-Gresham, Jennifer L.; de Craen, Anton J. M.; Bis, Joshua C.; Bonnefond, Amélie; Boucher, Gabrielle; Cadby, Gemma; Cheng, Yu-Ching; Chiang, Charleston W. K.; Delgado, Graciela; Demirkan, Ayse; Dueker, Nicole; Eklund, Niina; Eiriksdottir, Gudny; Eriksson, Joel; Feenstra, Bjarke; Fischer, Krista; Frau, Francesca; Galesloot, Tessel E.; Geller, Frank; Goel, Anuj; Gorski, Mathias; Grammer, Tanja B.; Gustafsson, Stefan; Haitjema, Saskia; Hottenga, Jouke-Jan; Huffman, Jennifer E.; Jackson, Anne U.; Jacobs, Kevin B.; Johansson, Åsa; Kaakinen, Marika; Kleber, Marcus E.; Lahti, Jari; Leach, Irene Mateo; Lehne, Benjamin; Liu, Youfang; Lo, Ken Sin; Lorentzon, Mattias; Luan, Jian'an; Madden, Pamela A. F.; Mangino, Massimo; McKnight, Barbara; Medina-Gomez, Carolina; Monda, Keri L.; Montasser, May E.; Müller, Gabriele; Müller-Nurasyid, Martina; Nolte, Ilja M.; Panoutsopoulou, Kalliope; Pascoe, Laura; Paternoster, Lavinia; Rayner, Nigel W.; Renström, Frida; Rizzi, Federica; Rose, Lynda M.; Ryan, Kathy A.; Salo, Perttu; Sanna, Serena; Scharnagl, Hubert; Shi, Jianxin; Smith, Albert Vernon; Southam, Lorraine; Stančáková, Alena; Steinthorsdottir, Valgerdur; Strawbridge, Rona J.; Sung, Yun Ju; Tachmazidou, Ioanna; Tanaka, Toshiko; Thorleifsson, Gudmar; Trompet, Stella; Pervjakova, Natalia; Tyrer, Jonathan P.; Vandenput, Liesbeth; van der Laan, Sander W; van der Velde, Nathalie; van Setten, Jessica; van Vliet-Ostaptchouk, Jana V.; Verweij, Niek; Vlachopoulou, Efthymia; Waite, Lindsay L.; Wang, Sophie R.; Wang, Zhaoming; Wild, Sarah H.; Willenborg, Christina; Wilson, James F.; Wong, Andrew; Yang, Jian; Yengo, Loïc; Yerges-Armstrong, Laura M.; Yu, Lei; Zhang, Weihua; Zhao, Jing Hua; Andersson, Ehm A.; Bakker, Stephan J. L.; Baldassarre, Damiano; Banasik, Karina; Barcella, Matteo; Barlassina, Cristina; Bellis, Claire; Benaglio, Paola; Blangero, John; Blüher, Matthias; Bonnet, Fabrice; Bonnycastle, Lori L.; Boyd, Heather A.; Bruinenberg, Marcel; Buchman, Aron S; Campbell, Harry; Chen, Yii-Der Ida; Chines, Peter S.; Claudi-Boehm, Simone; Cole, John; Collins, Francis S.; de Geus, Eco J. C.; de Groot, Lisette C. P. G. M.; Dimitriou, Maria; Duan, Jubao; Enroth, Stefan; Eury, Elodie; Farmaki, Aliki-Eleni; Forouhi, Nita G.; Friedrich, Nele; Gejman, Pablo V.; Gigante, Bruna; Glorioso, Nicola; Go, Alan S.; Gottesman, Omri; Gräßler, Jürgen; Grallert, Harald; Grarup, Niels; Gu, Yu-Mei; Broer, Linda; Ham, Annelies C.; Hansen, Torben; Harris, Tamara B.; Hartman, Catharina A.; Hassinen, Maija; Hastie, Nicholas; Hattersley, Andrew T.; Heath, Andrew C.; Henders, Anjali K.; Hernandez, Dena; Hillege, Hans; Holmen, Oddgeir; Hovingh, Kees G; Hui, Jennie; Husemoen, Lise L.; Hutri-Kähönen, Nina; Hysi, Pirro G.; Illig, Thomas; De Jager, Philip L.; Jalilzadeh, Shapour; Jørgensen, Torben; Jukema, J. Wouter; Juonala, Markus; Kanoni, Stavroula; Karaleftheri, Maria; Khaw, Kay Tee; Kinnunen, Leena; Kittner, Steven J.; Koenig, Wolfgang; Kolcic, Ivana; Kovacs, Peter; Krarup, Nikolaj T.; Kratzer, Wolfgang; Krüger, Janine; Kuh, Diana; Kumari, Meena; Kyriakou, Theodosios; Langenberg, Claudia; Lannfelt, Lars; Lanzani, Chiara; Lotay, Vaneet; Launer, Lenore J.; Leander, Karin; Lindström, Jaana; Linneberg, Allan; Liu, Yan-Ping; Lobbens, Stéphane; Luben, Robert; Lyssenko, Valeriya; Männistö, Satu; Magnusson, Patrik K.; McArdle, Wendy L.; Menni, Cristina; Merger, Sigrun; Milani, Lili; Montgomery, Grant W.; Morris, Andrew P.; Narisu, Narisu; Nelis, Mari; Ong, Ken K.; Palotie, Aarno; Pérusse, Louis; Pichler, Irene; Pilia, Maria G.; Pouta, Anneli; Rheinberger, Myriam; Ribel-Madsen, Rasmus; Richards, Marcus; Rice, Kenneth M.; Rice, Treva K.; Rivolta, Carlo; Salomaa, Veikko; Sanders, Alan R.; Sarzynski, Mark A.; Scholtens, Salome; Scott, Robert A.; Scott, William R.; Sebert, Sylvain; Sengupta, Sebanti; Sennblad, Bengt; Seufferlein, Thomas; Silveira, Angela; Slagboom, P. Eline; Smit, Jan H.; Sparsø, Thomas H.; Stirrups, Kathleen; Stolk, Ronald P.; Stringham, Heather M.; Swertz, Morris A; Swift, Amy J.; Syvänen, Ann-Christine; Tan, Sian-Tsung; Thorand, Barbara; Tönjes, Anke; Tremblay, Angelo; Tsafantakis, Emmanouil; van der Most, Peter J.; Völker, Uwe; Vohl, Marie-Claude; Vonk, Judith M.; Waldenberger, Melanie; Walker, Ryan W.; Wennauer, Roman; Widén, Elisabeth; Willemsen, Gonneke; Wilsgaard, Tom; Wright, Alan F.; Zillikens, M. Carola; van Dijk, Suzanne C.; van Schoor, Natasja M.; Asselbergs, Folkert W.; de Bakker, Paul I. W.; Beckmann, Jacques S.; Beilby, John; Bennett, David A.; Bergman, Richard N.; Bergmann, Sven; Böger, Carsten A.; Boehm, Bernhard O.; Boerwinkle, Eric; Boomsma, Dorret I.; Bornstein, Stefan R.; Bottinger, Erwin P.; Bouchard, Claude; Chambers, John C.; Chanock, Stephen J.; Chasman, Daniel I.; Cucca, Francesco; Cusi, Daniele; Dedoussis, George; Erdmann, Jeanette; Eriksson, Johan G.; Evans, Denis A.; de Faire, Ulf; Farrall, Martin; Ferrucci, Luigi; Ford, Ian; Franke, Lude; Franks, Paul W.; Froguel, Philippe; Gansevoort, Ron T.; Gieger, Christian; Grönberg, Henrik; Gudnason, Vilmundur; Gyllensten, Ulf; Hall, Per; Hamsten, Anders; van der Harst, Pim; Hayward, Caroline; Heliövaara, Markku; Hengstenberg, Christian; Hicks, Andrew A; Hingorani, Aroon; Hofman, Albert; Hu, Frank; Huikuri, Heikki V.; Hveem, Kristian; James, Alan L.; Jordan, Joanne M.; Jula, Antti; Kähönen, Mika; Kajantie, Eero; Kathiresan, Sekar; Kiemeney, Lambertus A. L. M.; Kivimaki, Mika; Knekt, Paul B.; Koistinen, Heikki A.; Kooner, Jaspal S.; Koskinen, Seppo; Kuusisto, Johanna; Maerz, Winfried; Martin, Nicholas G; Laakso, Markku; Lakka, Timo A.; Lehtimäki, Terho; Lettre, Guillaume; Levinson, Douglas F.; Lind, Lars; Lokki, Marja-Liisa; Mäntyselkä, Pekka; Melbye, Mads; Metspalu, Andres; Mitchell, Braxton D.; Moll, Frans L.; Murray, Jeffrey C.; Musk, Arthur W.; Nieminen, Markku S.; Njølstad, Inger; Ohlsson, Claes; Oldehinkel, Albertine J.; Oostra, Ben A.; Palmer, Lyle J; Pankow, James S.; Pasterkamp, Gerard; Pedersen, Nancy L.; Pedersen, Oluf; Penninx, Brenda W.; Perola, Markus; Peters, Annette; Polašek, Ozren; Pramstaller, Peter P.; Psaty, Bruce M.; Qi, Lu; Quertermous, Thomas; Raitakari, Olli T.; Rankinen, Tuomo; Rauramaa, Rainer; Ridker, Paul M.; Rioux, John D.; Rivadeneira, Fernando; Rotter, Jerome I.; Rudan, Igor; den Ruijter, Hester M.; Saltevo, Juha; Sattar, Naveed; Schunkert, Heribert; Schwarz, Peter E. H.; Shuldiner, Alan R.; Sinisalo, Juha; Snieder, Harold; Sørensen, Thorkild I. A.; Spector, Tim D.; Staessen, Jan A.; Stefania, Bandinelli; Thorsteinsdottir, Unnur; Stumvoll, Michael; Tardif, Jean-Claude; Tremoli, Elena; Tuomilehto, Jaakko; Uitterlinden, André G.; Uusitupa, Matti; Verbeek, André L. M.; Vermeulen, Sita H.; Viikari, Jorma S.; Vitart, Veronique; Völzke, Henry; Vollenweider, Peter; Waeber, Gérard; Walker, Mark; Wallaschofski, Henri; Wareham, Nicholas J.; Watkins, Hugh; Zeggini, Eleftheria; Chakravarti, Aravinda; Clegg, Deborah J.; Cupples, L. Adrienne; Gordon-Larsen, Penny; Jaquish, Cashell E.; Rao, D. C.; Abecasis, Goncalo R.; Assimes, Themistocles L.; Barroso, Inês; Berndt, Sonja I.; Boehnke, Michael; Deloukas, Panos; Fox, Caroline S.; Groop, Leif C.; Hunter, David J.; Ingelsson, Erik; Kaplan, Robert C.; McCarthy, Mark I.; Mohlke, Karen L.; O'Connell, Jeffrey R.; Schlessinger, David; Strachan, David P.; Stefansson, Kari; van Duijn, Cornelia M.; Hirschhorn, Joel N.; Lindgren, Cecilia M.; Heid, Iris M.; North, Kari E.; Borecki, Ingrid B.; Kutalik, Zoltán; Loos, Ruth J. F.

2015-01-01

Genome-wide association studies (GWAS) have identified more than 100 genetic variants contributing to BMI, a measure of body size, or waist-to-hip ratio (adjusted for BMI, WHRadjBMI), a measure of body shape. Body size and shape change as people grow older and these changes differ substantially between men and women. To systematically screen for age- and/or sex-specific effects of genetic variants on BMI and WHRadjBMI, we performed meta-analyses of 114 studies (up to 320,485 individuals of European descent) with genome-wide chip and/or Metabochip data by the Genetic Investigation of Anthropometric Traits (GIANT) Consortium. Each study tested the association of up to ~2.8M SNPs with BMI and WHRadjBMI in four strata (men ≤50y, men >50y, women ≤50y, women >50y) and summary statistics were combined in stratum-specific meta-analyses. We then screened for variants that showed age-specific effects (G x AGE), sex-specific effects (G x SEX) or age-specific effects that differed between men and women (G x AGE x SEX). For BMI, we identified 15 loci (11 previously established for main effects, four novel) that showed significant (FDR<5%) age-specific effects, of which 11 had larger effects in younger (<50y) than in older adults (≥50y). No sex-dependent effects were identified for BMI. For WHRadjBMI, we identified 44 loci (27 previously established for main effects, 17 novel) with sex-specific effects, of which 28 showed larger effects in women than in men, five showed larger effects in men than in women, and 11 showed opposite effects between sexes. No age-dependent effects were identified for WHRadjBMI. This is the first genome-wide interaction meta-analysis to report convincing evidence of age-dependent genetic effects on BMI. In addition, we confirm the sex-specificity of genetic effects on WHRadjBMI. These results may provide further insights into the biology that underlies weight change with age or the sexually dimorphism of body shape. PMID:26426971

Effectiveness and harms of seasonal and pandemic influenza vaccines in children, adults and elderly

PubMed Central

Manzoli, Lamberto; Ioannidis, John P.A.; Flacco, Maria Elena; De Vito, Corrado; Villari, Paolo

2012-01-01

Fifteen meta-analyses have been published between 1995 and 2011 to evaluate the efficacy/effectiveness and harms of diverse influenza vaccines—seasonal, H5N1 and 2009(H1N1) —in various age-classes (healthy children, adults or elderly). These meta-analyses have often adopted different analyses and study selection criteria. Because it is difficult to have a clear picture of vaccine benefits and harms examining single systematic reviews, we compiled the main findings and evaluated which could be the most reasonable explanations for some differences in findings (or their interpretation) across previously published meta-analyses. For each age group, we performed analyses that included all trials that had been included in at least one relevant meta-analysis, also exploring whether effect sizes changed over time. Although we identified several discrepancies among the meta-analyses on seasonal vaccines for children and elderly, overall most seasonal influenza vaccines showed statistically significant efficacy/effectiveness, which was acceptable or high for laboratory-confirmed cases and of modest magnitude for clinically-confirmed cases. The available evidence on parenteral inactivated vaccines for children aged < 2 y remains scarce. Pre-pandemic “avian” H5N1 and pandemic 2009 (H1N1) vaccines can achieve satisfactory immunogenicity, but no meta-analysis has addressed H1N1 vaccination impact on clinical outcomes. Data on harms are overall reassuring, but their value is diminished by inconsistent reporting. PMID:22777099

Overlooking the obvious: a meta-analytic comparison of digit symbol coding tasks and other cognitive measures in schizophrenia.

PubMed

Dickinson, Dwight; Ramsey, Mary E; Gold, James M

2007-05-01

In focusing on potentially localizable cognitive impairments, the schizophrenia meta-analytic literature has overlooked the largest single impairment: on digit symbol coding tasks. To compare the magnitude of the schizophrenia impairment on coding tasks with impairments on other traditional neuropsychological instruments. MEDLINE and PsycINFO electronic databases and reference lists from identified articles. English-language studies from 1990 to present, comparing performance of patients with schizophrenia and healthy controls on coding tasks and cognitive measures representing at least 2 other cognitive domains. Of 182 studies identified, 40 met all criteria for inclusion in the meta-analysis. Means, standard deviations, and sample sizes were extracted for digit symbol coding and 36 other cognitive variables. In addition, we recorded potential clinical moderator variables, including chronicity/severity, medication status, age, and education, and potential study design moderators, including coding task variant, matching, and study publication date. Main analyses synthesized data from 37 studies comprising 1961 patients with schizophrenia and 1444 comparison subjects. Combination of mean effect sizes across studies by means of a random effects model yielded a weighted mean effect for digit symbol coding of g = -1.57 (95% confidence interval, -1.66 to -1.48). This effect compared with a grand mean effect of g = -0.98 and was significantly larger than effects for widely used measures of episodic memory, executive functioning, and working memory. Moderator variable analyses indicated that clinical and study design differences between studies had little effect on the coding task effect. Comparison with previous meta-analyses suggested that current results were representative of the broader literature. Subsidiary analysis of data from relatives of patients with schizophrenia also suggested prominent coding task impairments in this group. The 5-minute digit symbol coding task, reliable and easy to administer, taps an information processing inefficiency that is a central feature of the cognitive deficit in schizophrenia and deserves systematic investigation.

Effectiveness of traditional meditation retreats: A systematic review and meta-analysis.

PubMed

Khoury, Bassam; Knäuper, Bärbel; Schlosser, Marco; Carrière, Kimberly; Chiesa, Alberto

2017-01-01

An increasing number of studies are investigating traditional meditation retreats. Very little, however, is known about their effectiveness. To evaluate the effectiveness of meditation retreats on improving psychological outcomes in general population. A systematic review of studies published in journals or as dissertations in PSYCINFO, PUBMED, CINAHL or Web of Science from the first available date until October 22, 2016. A total of 20 papers (21 studies, N=2912) were included. Effect-size estimates of outcomes combined suggested that traditional meditation retreats are moderately effective in pre-post analyses (n=19; Hedge's g=0.45; 95% CI [0.35, 0.54], p<0.00001) and in analyses comparing retreats to controls (n=14; Hedge's g=0.49; 95% CI [0.36, 0.61], p<0.00001). Results were maintained at follow-up. No differences were observed between meditation styles. Results suggested large effects on measures of anxiety, depression and stress, and moderate effects on measures of emotional regulation and quality of life. As to potential mechanisms of actions, results showed large effects on measures of mindfulness and compassion, and moderate effects on measures of acceptance. In addition, changes in mindfulness levels strongly moderated clinical effect sizes. However, heterogeneity was significant among trials, probably due to differences in study designs, types and duration of the retreats and assessed outcomes, limiting therefore the implications of the results. Meditation retreats are moderately to largely effective in reducing depression, anxiety, stress and in ameliorating the quality of life of participants. Copyright © 2016 Elsevier Inc. All rights reserved.

Size Effects in Impact Damage of Composite Sandwich Panels

NASA Technical Reports Server (NTRS)

Dobyns, Alan; Jackson, Wade

2003-01-01

Panel size has a large effect on the impact response and resultant damage level of honeycomb sandwich panels. It has been observed during impact testing that panels of the same design but different panel sizes will show large differences in damage when impacted with the same impact energy. To study this effect, a test program was conducted with instrumented impact testing of three different sizes of sandwich panels to obtain data on panel response and residual damage. In concert with the test program. a closed form analysis method was developed that incorporates the effects of damage on the impact response. This analysis method will predict both the impact response and the residual damage of a simply-supported sandwich panel impacted at any position on the panel. The damage is incorporated by the use of an experimental load-indentation curve obtained for the face-sheet/honeycomb and indentor combination under study. This curve inherently includes the damage response and can be obtained quasi-statically from a rigidly-backed specimen or a specimen with any support conditions. Good correlation has been obtained between the test data and the analysis results for the maximum force and residual indentation. The predictions can be improved by using a dynamic indentation curve. Analyses have also been done using the MSC/DYTRAN finite element code.

Judging arrival times of incoming traffic vehicles is not a prerequisite for safely crossing an intersection: Differential effects of vehicle size and type in passive judgment and active driving tasks.

PubMed

Mathieu, Julie; Bootsma, Reinoud J; Berthelon, Catherine; Montagne, Gilles

2017-02-01

Using a fixed-base driving simulator we compared the effects of the size and type of traffic vehicles (i.e., normal-sized or double-sized cars or motorcycles) approaching an intersection in two different tasks. In the perceptual judgment task, passively moving participants estimated when a traffic vehicle would reach the intersection for actual arrival times (ATs) of 1, 2, or 3s. In line with earlier findings, ATs were generally underestimated, the more so the longer the actual AT. Results revealed that vehicle size affected judgments in particular for the larger actual ATs (2 and 3s), with double-sized vehicles then being judged as arriving earlier than normal-sized vehicles. Vehicle type, on the other hand, affected judgments at the smaller actual ATs (1 and 2s), with cars then being judged as arriving earlier than motorcycles. In the behavioral task participants actively drove the simulator to cross the intersection by passing through a gap in a train of traffic. Analyses of the speed variations observed during the active intersection-crossing task revealed that the size and type of vehicles in the traffic train did not affect driving behavior in the same way as in the AT judgment task. First, effects were considerably smaller, affecting driving behavior only marginally. Second, effects were opposite to expectations based on AT judgments: driver approach speeds were smaller (rather than larger) when confronted with double-sized vehicles as compared to their normal-sized counterparts and when confronted with cars as compared to motorcycles. Finally, the temporality of the effects was different on the two tasks: vehicle size affected driver approach speed in the final stages of approach rather than early on, while vehicle type affected driver approach speed early on rather than later. Overall, we conclude that the active control of approach to the intersection is not based on successive judgments of traffic vehicle arrival times. These results thereby question the general belief that arrival time estimates are crucial for safe interaction with traffic. Copyright © 2016 Elsevier B.V. All rights reserved.

Effect of High-Frequency Transcranial Magnetic Stimulation on Craving in Substance Use Disorder: A Meta-Analysis.

PubMed

Maiti, Rituparna; Mishra, Biswa Ranjan; Hota, Debasish

2017-01-01

Repetitive transcranial magnetic stimulation (rTMS), a noninvasive, neuromodulatory tool, has been used to reduce craving in different substance use disorders. There are some studies that have reported conflicting and inconclusive results; therefore, this meta-analysis was conducted to evaluate the effect of high-frequency rTMS on craving in substance use disorder and to investigate the reasons behind the inconsistency across the studies. The authors searched clinical trials from MEDLINE, Cochrane databases, and International Clinical Trials Registry Platform. The PRISMA guidelines, as well as recommended meta-analysis practices, were followed in the selection process, analysis, and reporting of the findings. The effect estimate used was the standardized mean difference (Hedge's g), and heterogeneity across the considered studies was explored using subgroup analyses. The quality assessment was done using the Cochrane risk of bias tool, and sensitivity analysis was performed to check the influences on effect size by statistical models. After screening and assessment of eligibility, finally 10 studies were included for meta-analysis, which includes six studies on alcohol and four studies on nicotine use disorder. The random-model analysis revealed a pooled effect size of 0.75 (95% CI=0.29 to 1.21, p=0.001), whereas the fixed-model analysis showed a large effect size of 0.87 (95% CI=0.63 to 1.12, p<0.00001). Subgroup analysis for alcohol use disorder showed an effect size of -0.06 (95% CI=-0.89 to 0.77, p=0.88). In the case of nicotine use disorder, random-model analysis revealed an effect size of 1.00 (95% CI=0.48 to 1.55, p=0.0001), whereas fixed-model analysis also showed a large effect size of 0.96 (95% CI=0.71 to 1.22). The present meta-analysis identified a beneficial effect of high-frequency rTMS on craving associated with nicotine use disorder but not alcohol use disorder.

Intra-specific variation in genome size in maize: cytological and phenotypic correlates

PubMed Central

Realini, María Florencia; Poggio, Lidia; Cámara-Hernández, Julián; González, Graciela Esther

2016-01-01

Genome size variation accompanies the diversification and evolution of many plant species. Relationships between DNA amount and phenotypic and cytological characteristics form the basis of most hypotheses that ascribe a biological role to genome size. The goal of the present research was to investigate the intra-specific variation in the DNA content in maize populations from Northeastern Argentina and further explore the relationship between genome size and the phenotypic traits seed weight and length of the vegetative cycle. Moreover, cytological parameters such as the percentage of heterochromatin as well as the number, position and sequence composition of knobs were analysed and their relationships with 2C DNA values were explored. The populations analysed presented significant differences in 2C DNA amount, from 4.62 to 6.29 pg, representing 36.15 % of the inter-populational variation. Moreover, intra-populational genome size variation was found, varying from 1.08 to 1.63-fold. The variation in the percentage of knob heterochromatin as well as in the number, chromosome position and sequence composition of the knobs was detected among and within the populations. Although a positive relationship between genome size and the percentage of heterochromatin was observed, a significant correlation was not found. This confirms that other non-coding repetitive DNA sequences are contributing to the genome size variation. A positive relationship between DNA amount and the seed weight has been reported in a large number of species, this relationship was not found in the populations studied here. The length of the vegetative cycle showed a positive correlation with the percentage of heterochromatin. This result allowed attributing an adaptive effect to heterochromatin since the length of this cycle would be optimized via selection for an appropriate percentage of heterochromatin. PMID:26644343

Statistical analyses support power law distributions found in neuronal avalanches.

PubMed

Klaus, Andreas; Yu, Shan; Plenz, Dietmar

2011-01-01

The size distribution of neuronal avalanches in cortical networks has been reported to follow a power law distribution with exponent close to -1.5, which is a reflection of long-range spatial correlations in spontaneous neuronal activity. However, identifying power law scaling in empirical data can be difficult and sometimes controversial. In the present study, we tested the power law hypothesis for neuronal avalanches by using more stringent statistical analyses. In particular, we performed the following steps: (i) analysis of finite-size scaling to identify scale-free dynamics in neuronal avalanches, (ii) model parameter estimation to determine the specific exponent of the power law, and (iii) comparison of the power law to alternative model distributions. Consistent with critical state dynamics, avalanche size distributions exhibited robust scaling behavior in which the maximum avalanche size was limited only by the spatial extent of sampling ("finite size" effect). This scale-free dynamics suggests the power law as a model for the distribution of avalanche sizes. Using both the Kolmogorov-Smirnov statistic and a maximum likelihood approach, we found the slope to be close to -1.5, which is in line with previous reports. Finally, the power law model for neuronal avalanches was compared to the exponential and to various heavy-tail distributions based on the Kolmogorov-Smirnov distance and by using a log-likelihood ratio test. Both the power law distribution without and with exponential cut-off provided significantly better fits to the cluster size distributions in neuronal avalanches than the exponential, the lognormal and the gamma distribution. In summary, our findings strongly support the power law scaling in neuronal avalanches, providing further evidence for critical state dynamics in superficial layers of cortex.

Modeling of Particle Agglomeration in Nanofluids

NASA Astrophysics Data System (ADS)

Kanagala, Hari Krishna

Nanofluids are colloidal dispersions of nano sized particles (<100nm in diameter) in dispersion mediums. They are of great interest in industrial applications as heat transfer fluids owing to their enhanced thermal conductivities. Stability of nanofluids is a major problem hindering their industrial application. Agglomeration and then sedimentation are some reasons, which drastically decrease the shelf life of these nanofluids. Current research addresses the agglomeration effect and how it can affect the shelf life of a nanofluid. The reasons for agglomeration in nanofluids are attributable to the interparticle interactions which are quantified by the various theories. By altering the governing properties like volume fraction, pH and electrolyte concentration different nanofluids with instant agglomeration, slow agglomeration and no agglomeration can be produced. A numerical model is created based on the discretized population balance equations which analyses the particle size distribution at different times. Agglomeration effects have been analyzed for alumina nanoparticles with average particle size of 150nm dispersed in de-ionized water. As the pH was moved towards the isoelectric point of alumina nanofluids, the particle size distribution became broader and moved to bigger sizes rapidly with time. Particle size distributions became broader and moved to bigger sizes more quickly with time with increase in the electrolyte concentration. The two effects together can be used to create different temporal trends in the particle size distributions. Faster agglomeration is attributed to the decrease in the electrostatic double layer repulsion forces which is due to decrease in the induced charge and the double layer thickness around the particle. Bigger particle clusters show lesser agglomeration due to reaching the equilibrium size. The procedures and processes described in this work can be used to generate more stable nanofluids.

Cross-seasonal effects on waterfowl productivity: Implications under climate change

USGS Publications Warehouse

Osnas, Erik; Zhao, Qing; Runge, Michael C.; Boomer, G Scott

2016-01-01

Previous efforts to relate winter-ground precipitation to subsequent reproductive success as measured by the ratio of juveniles to adults in the autumn failed to account for increased vulnerability of juvenile ducks to hunting and uncertainty in the estimated age ratio. Neglecting increased juvenile vulnerability will positively bias the mean productivity estimate, and neglecting increased vulnerability and estimation uncertainty will positively bias the year-to-year variance in productivity because raw age ratios are the product of sampling variation, the year-specific vulnerability, and year-specific reproductive success. Therefore, we estimated the effects of cumulative winter precipitation in the California Central Valley and the Mississippi Alluvial Valley on pintail (Anas acuta) and mallard (Anas platyrhnchos) reproduction, respectively, using hierarchical Bayesian methods to correct for sampling bias in productivity estimates and observation error in covariates. We applied the model to a hunter-collected parts survey implemented by the United States Fish and Wildlife Service and band recoveries reported to the United States Geological Survey Bird Banding Laboratory using data from 1961 to 2013. We compared our results to previous estimates that used simple linear regression on uncorrected age ratios from a smaller subset of years in pintail (1961–1985). Like previous analyses, we found large and consistent effects of population size and wetland conditions in prairie Canada on mallard productivity, and large effects of population size and mean latitude of the observed breeding population on pintail productivity. Unlike previous analyses, we report a large amount of uncertainty in the estimated effects of wintering-ground precipitation on pintail and mallard productivity, with considerable uncertainty in the sign of the estimated main effect, although the posterior medians of precipitation effects were consistent with past studies. We found more consistent estimates in the sign of an interaction effect between population size and precipitation, suggesting that wintering-ground precipitation has a larger effect in years of high population size, especially for pintail. When we used the estimated effects in a population model to derive a sustainable harvest and population size projection (i.e., a yield curve), there was considerable uncertainty in the effect of increased or decreased wintering-ground precipitation on sustainable harvest potential and population size. These results suggest that the mechanism of cross-seasonal effects between winter habitat and reproduction in ducks occurs through a reduction in the strength of density dependence in years of above-average wintering-ground precipitation. We suggest additional investigation of the underlying mechanisms and that habitat managers and decision-makers consider the level of uncertainty in these estimates when attempting to integrate habitat management and harvest management decisions. Collection of annual data on the status of wintering-ground habitat in a rigorous sampling framework would likely be the most direct way to improve understanding of mechanisms and inform management.

Combining the role of convenience and consideration set size in explaining fish consumption in Norway.

PubMed

Rortveit, Asbjorn Warvik; Olsen, Svein Ottar

2009-04-01

The purpose of this study is to explore how convenience orientation, perceived product inconvenience and consideration set size are related to attitudes towards fish and fish consumption. The authors present a structural equation model (SEM) based on the integration of two previous studies. The results of a SEM analysis using Lisrel 8.72 on data from a Norwegian consumer survey (n=1630) suggest that convenience orientation and perceived product inconvenience have a negative effect on both consideration set size and consumption frequency. Attitude towards fish has the greatest impact on consumption frequency. The results also indicate that perceived product inconvenience is a key variable since it has a significant impact on attitude, and on consideration set size and consumption frequency. Further, the analyses confirm earlier findings suggesting that the effect of convenience orientation on consumption is partially mediated through perceived product inconvenience. The study also confirms earlier findings suggesting that the consideration set size affects consumption frequency. Practical implications drawn from this research are that the seafood industry would benefit from developing and positioning products that change beliefs about fish as an inconvenient product. Future research for other food categories should be done to enhance the external validity.

Pulsed Tm:YAG laser ablation of knee joint tissues

NASA Astrophysics Data System (ADS)

Shi, Wei-Qiang; Vari, Sandor G.; Duffy, J. T.; Miller, J. M.; Weiss, Andrew B.; Fishbein, Michael C.; Grundfest, Warren S.

1992-06-01

We investigated the effect of a free-running 2.01 micron pulsed Tm:YAG laser on bovine knee joint tissues. Ablation rates of fresh fibrocartilage, hyaline cartilage, and bone were measured in saline as a function of laser fluence (160 - 640 J/cm2) and fiber core size (400 and 600 microns). All tissues could be effectively ablated and the ablation rate increased linearly with the increasing fluence. Use of fibers of different core sizes, while maintaining constant energy fluence, did not result in significant difference in ablation rate. Histology analyses of the ablated tissue samples reveal average Tm:YAG radiation induced thermal damage (denatunalization) zones ranging between 130 and 540 microns, depending on the laser parameters and the tissue type.

Are K-12 learners motivated in physical education? A meta-analysis.

PubMed

Chen, Senlin; Chen, Ang; Zhu, Xihe

2012-03-01

Previous studies devoted to K-12 learner motivation in physical education share a general assumption that students may lack motivation. This meta-analytic study examined published original studies (n = 79) to determine students' motivation level and the association between motivation and outcomes. Original means of motivation measures were converted and aggregated to determine motivation levels. Correlation effect sizes were calculated to determine the association between motivation and outcome measures. The analyses revealed that K-12 students are motivated regardless of the theoretical constructs used in the studies (M > 50). The correlation effect sizes (r = .20-.30, p < .05) indicate a weak association between motivation and outcome. The findings suggest a need to involve meaningful learning and pedagogy variables in motivation research.

The Efficacy of Violence Prediction: A Meta-Analytic Comparison of Nine Risk Assessment Tools

ERIC Educational Resources Information Center

Yang, Min; Wong, Stephen C. P.; Coid, Jeremy

2010-01-01

Actuarial risk assessment tools are used extensively to predict future violence, but previous studies comparing their predictive accuracies have produced inconsistent findings as a result of various methodological issues. We conducted meta-analyses of the effect sizes of 9 commonly used risk assessment tools and their subscales to compare their…

The Relative Benefits of Meta-Analysis Conducted with Individual Participant Data versus Aggregated Data

ERIC Educational Resources Information Center

Cooper, Harris; Patall, Erika A.

2009-01-01

The authors describe the relative benefits of conducting meta-analyses with (a) individual participant data (IPD) gathered from the constituent studies and (b) aggregated data (AD), or the group-level statistics (in particular, effect sizes) that appear in reports of a study's results. Given that both IPD and AD are equally available,…

Consequences of Not Accounting for One-Group Clustering in Meta-Analysis

ERIC Educational Resources Information Center

Citkowicz, Martyna; Polanin, Joshua R.

2014-01-01

Meta-analyses are syntheses of effect-size estimates obtained from a collection of studies to summarize a particular field or topic (Hedges, 1992; Lipsey & Wilson, 2001). These reviews are used to integrate knowledge that can inform both scientific inquiry and public policy, therefore it is important to ensure that the estimates of the effect…

Using Generalized Additive Models to Analyze Single-Case Designs

ERIC Educational Resources Information Center

Shadish, William; Sullivan, Kristynn

2013-01-01

Many analyses for single-case designs (SCDs)--including nearly all the effect size indicators-- currently assume no trend in the data. Regression and multilevel models allow for trend, but usually test only linear trend and have no principled way of knowing if higher order trends should be represented in the model. This paper shows how Generalized…

Multilocus analyses reveal little evidence for lineage-wide adaptive evolution within major clades of soft pines (Pinus subgenus Strobus)

Treesearch

Andrew J. Eckert; Andrew D. Bower; Kathleen D. Jermstad; Jill L. Wegrzyn; Brian J. Knaus; John V. Syring; David B. Neale

2013-01-01

Estimates from molecular data for the fraction of new nonsynonymous mutations that are adaptive vary strongly across plant species. Much of this variation is due to differences in life history strategies as they influence the effective population size (Ne). Ample variation for these estimates, however, remains even when...

Regional forest fragmentation effects on bottomland hardwood community types and resource values

Treesearch

Victor A. Rudis

1995-01-01

In human-dominated regions, forest vegetation removal impacts remaining ecosystems but regional-scale biological consequences and resource value changes are not well known. Using forest resource survey data, I examined current bottomland hardwood community types and a range of fragment size classes in the south central United States. Analyses examined resource value...

The Impact of Baseline Trend Control on Visual Analysis of Single-Case Data

ERIC Educational Resources Information Center

Mercer, Sterett H.; Sterling, Heather E.

2012-01-01

The impact of baseline trend control on visual analyses of AB intervention graphs was examined with simulated data at various values of baseline trend, autocorrelation, and effect size. Participants included 202 undergraduate students with minimal training in visual analysis and 10 graduate students and faculty with more training and experience in…

Brokerage and SME Innovation: An Analysis of the Technology Transfer Service at Area Science Park, Italy

ERIC Educational Resources Information Center

Cattapan, Paolo; Passarelli, Mariacarmela; Petrone, Michele

2012-01-01

This paper contributes to the literature on innovation brokerage by analysing the effects of brokerage activities on the innovation and growth of small and medium-sized enterprises (SMEs). The authors provide a detailed description of the Technology Transfer Service (TTS), credited as a European best-practice innovation broker, at Area Science…

The effect of particle size on the dehydration/rehydration behaviour of lactose.

PubMed

Crisp, J L; Dann, S E; Edgar, M; Blatchford, C G

2010-05-31

Ethanolic suspensions of spray dried and micronized alpha lactose monohydrate (L(alpha)xH(2)O) with average particle size between 3 and 200 microm, have been prepared and their dehydration behaviour was investigated by (13)C CP-MASNMR spectroscopy. Sub-micron lactose suspension prepared by a novel high pressure homogenisation method has been compared with the standard ethanolic suspensions of (L(alpha).H(2)O prepared by reflux or static room temperature methods. In all cases, suspensions were shown to contain the stable anhydrous form of lactose ((L(alpha)(S)). Several approaches were employed to remove ethanol from these suspensions and the resulting dry lactose powders were then analysed by FT-IR, PXRD and SEM to evaluate the effect of drying procedure on type and distribution of lactose polymorphs and particle size. For samples with mean particle size greater than 1 microm, the stable anhydrous polymorphic form of lactose was retained on removal of the ethanol, although differences in the morphology and particle size of the crystals were apparent depending on method of suspension formation. Sub-micron (L(alpha)(S), while stable in dry conditions, has been shown to be less stable to atmospheric water vapour than (L(alpha)(S) with particle size between 3 and 200 microm. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Statistical power and effect sizes of depression research in Japan.

PubMed

Okumura, Yasuyuki; Sakamoto, Shinji

2011-06-01

Few studies have been conducted on the rationales for using interpretive guidelines for effect size, and most of the previous statistical power surveys have covered broad research domains. The present study aimed to estimate the statistical power and to obtain realistic target effect sizes of depression research in Japan. We systematically reviewed 18 leading journals of psychiatry and psychology in Japan and identified 974 depression studies that were mentioned in 935 articles published between 1990 and 2006. In 392 studies, logistic regression analyses revealed that using clinical populations was independently associated with being a statistical power of <0.80 (odds ratio 5.9, 95% confidence interval 2.9-12.0) and of <0.50 (odds ratio 4.9, 95% confidence interval 2.3-10.5). Of the studies using clinical populations, 80% did not achieve a power of 0.80 or more, and 44% did not achieve a power of 0.50 or more to detect the medium population effect sizes. A predictive model for the proportion of variance explained was developed using a linear mixed-effects model. The model was then used to obtain realistic target effect sizes in defined study characteristics. In the face of a real difference or correlation in population, many depression researchers are less likely to give a valid result than simply tossing a coin. It is important to educate depression researchers in order to enable them to conduct an a priori power analysis. © 2011 The Authors. Psychiatry and Clinical Neurosciences © 2011 Japanese Society of Psychiatry and Neurology.

Associations of Quality of Life with Service Satisfaction in Psychotic Patients: A Meta-Analysis

PubMed Central

Petkari, Eleni; Pietschnig, Jakob

2015-01-01

Background Quality of life (QoL) has gained increasing attention as a desired outcome of psychosocial treatments targeting psychotic patients. Yet, the relationship between the patients’ satisfaction with services and QoL has not been clearly established, perhaps due to the multidimensionality of the QoL concept and the variability in its assessment. Aim This is the first systematic meta-analysis of all available evidence assessing the relationship between QoL and service satisfaction. Methods: In all, 19 studies reporting data of 21 independent samples (N = 5,337) were included in the present meta-analysis. In moderator analyses, effects of age, sex, diagnoses (schizophrenia vs. other psychoses), treatment context (inpatients vs. outpatients), study design (cross-sectional vs. longitudinal), and QoL domain (subjective vs. health-related) were examined. Results Analyses revealed a highly significant medium-sized effect (r = .30, p < .001) for the associations of QoL and service satisfaction. Effect sizes were significantly stronger for subjective than health-related quality of life (r = .35 vs. r = .14, respectively). Moreover, associations with subjective QoL remained largely robust when accounting for moderating variables, although there was a trend of stronger associations for outpatients compared to inpatients. In contrast, effect sizes for health-related QoL were small and only observable for samples with longitudinal designs. Conclusion Associations between QoL and service satisfaction appear to be robust but are differentiated in regard to QoL domain. Our findings suggest that agents responsible for service design and implementation need to take the patients’ perception of the service adequacy for achieving QoL enhancement into account. PMID:26275139

Correction to storm, Tressoldi, and di Risio (2010).

PubMed

2015-03-01

Reports an error in "Meta-analysis of free-response studies, 1992-2008: Assessing the noise reduction model in parapsychology" by Lance Storm, Patrizio E. Tressoldi and Lorenzo Di Risio (Psychological Bulletin, 2010[Jul], Vol 136[4], 471-485). In the article, the sentence giving the formula in the second paragraph on p. 479 was stated incorrectly. The corrected sentence is included. (The following abstract of the original article appeared in record 2010-12718-001.) [Correction Notice: An erratum for this article was reported in Vol 136(5) of Psychological Bulletin (see record 2010-17510-009). In the article, the second to last sentence of the abstract (p. 471) was stated incorrectly. The sentence should read as follows: "The mean effect size value of the ganzfeld database was significantly higher than the mean effect size of the standard free-response database but was not higher than the effect size of the nonganzfeld noise reduction database."] We report the results of meta-analyses on 3 types of free-response study: (a) ganzfeld (a technique that enhances a communication anomaly referred to as "psi"); (b) nonganzfeld noise reduction using alleged psi-enhancing techniques such as dream psi, meditation, relaxation, or hypnosis; and (c) standard free response (nonganzfeld, no noise reduction). For the period 1997-2008, a homogeneous data set of 29 ganzfeld studies yielded a mean effect size of 0.142 (Stouffer Z = 5.48, p = 2.13 × 10-8). A homogeneous nonganzfeld noise reduction data set of 16 studies yielded a mean effect size of 0.110 (Stouffer Z = 3.35, p = 2.08 × 10-4), and a homogeneous data set of 14 standard free-response studies produced a weak negative mean effect size of -0.029 (Stouffer Z = -2.29, p = .989). The mean effect size value of the ganzfeld database were significantly higher than the mean effect size of the nonganzfeld noise reduction and the standard free-response databases. We also found that selected participants (believers in the paranormal, meditators, etc.) had a performance advantage over unselected participants, but only if they were in the ganzfeld condition. PsycINFO Database Record (c) 2015 APA, all rights reserved.

Evaluation of type 2 diabetes genetic risk variants in Chinese adults: findings from 93,000 individuals from the China Kadoorie Biobank.

PubMed

Gan, Wei; Walters, Robin G; Holmes, Michael V; Bragg, Fiona; Millwood, Iona Y; Banasik, Karina; Chen, Yiping; Du, Huaidong; Iona, Andri; Mahajan, Anubha; Yang, Ling; Bian, Zheng; Guo, Yu; Clarke, Robert J; Li, Liming; McCarthy, Mark I; Chen, Zhengming

2016-07-01

Genome-wide association studies (GWAS) have discovered many risk variants for type 2 diabetes. However, estimates of the contributions of risk variants to type 2 diabetes predisposition are often based on highly selected case-control samples, and reliable estimates of population-level effect sizes are missing, especially in non-European populations. The individual and cumulative effects of 59 established type 2 diabetes risk loci were measured in a population-based China Kadoorie Biobank (CKB) study of 93,000 Chinese adults, including >7,100 diabetes cases. Association signals were directionally consistent between CKB and the original discovery GWAS: of 56 variants passing quality control, 48 showed the same direction of effect (binomial test, p = 2.3 × 10(-8)). We observed a consistent overall trend towards lower risk variant effect sizes in CKB than in case-control samples of GWAS meta-analyses (mean 19-22% decrease in log odds, p ≤ 0.0048), likely to reflect correction of both 'winner's curse' and spectrum bias effects. The association with risk of diabetes of a genetic risk score, based on lead variants at 25 loci considered to act through beta cell function, demonstrated significant interactions with several measures of adiposity (BMI, waist circumference [WC], WHR and percentage body fat [PBF]; all p interaction < 1 × 10(-4)), with a greater effect being observed in leaner adults. Our study provides further evidence of shared genetic architecture for type 2 diabetes between Europeans and East Asians. It also indicates that even very large GWAS meta-analyses may be vulnerable to substantial inflation of effect size estimates, compared with those observed in large-scale population-based cohort studies. Details of how to access China Kadoorie Biobank data and details of the data release schedule are available from www.ckbiobank.org/site/Data+Access .

Effect of sodium azide addition and aging storage on casein micelle size

NASA Astrophysics Data System (ADS)

Sinaga, H.; Deeth, H.; Bhandari, B.

2018-02-01

Casein micelles affected most of milk properties, therefore the use sodium azide as milk preservation is not expected to alter milk properties during storage, including the casein micelle size. The aim of this study was to analyse casein micelle size after the addition of sodium azide during storage. The experiment was performed as a complete block randomised design with three replications. The addition of 0.02-0.10% Na-azide do not lead to any noticeable differences in average casein size at the same day and show similar trend after 14 day-storage. At concentration of 0.02% sodium azide (Na-azide), the size of pasteurised milk did not change up to 12 days, while the size of raw skim milk slightly increased by ageing time at day 5. The treated concentration did not affect the size distribution, except for milk with 0.02% Na-azide which had narrower distribution compared to other treated and control milk. The finding from this study suggests that the role of Na-azide in this experiments during storage at 4°C is only for preventing the microbial growth.

Electrical Characteristics CuFe{sub 2}O{sub 4} Thick Film Ceramics Made with Different Screen Size Utilizing Fe{sub 2}O{sub 3} Nanopowder Derived from Yarosite for NTC Thermistor

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

Wiendartun,; Syarif, Dani Gustaman

2010-10-24

Fabrication of CuFe{sub 2}O{sub 4} thick film ceramics utilizing Fe{sub 2}O{sub 3} derived from yarosite using screen printing technique for NTC thermistor has been carried out. Effect of thickness variation due to different size of screen (screen 225; 300 and 375 mesh) has been studied. X-ray diffraction analyses (XRD) was done to know crystal structure and phases formation. SEM analyses was carried out to know microstructure of the films. Electrical properties characterization was done through measurement of electrical resistance at various temperatures (room temperature to 100 deg. C). The XRD data showed that the films crystalize in tetragonal spinel. Themore » SEM images showed that the screen with the smaller of the hole size, made the grain size was bigger. Electrical data showed that the larger the screen different size thickness variation (mesh), the larger the resistance, thermistor constant and sensitivity. From the electrical characteristics data, it was known that the electrical characteristics of the CuFe{sub 2}O{sub 4} thick film ceramics followed the NTC characteristic. The value of B and R{sub RT} of the produced CuFe{sub 2}O{sub 4} ceramics namely B = 3241-3484 K and R{sub RT} = 25.6-87.0 M Ohm, fitted market requirement.« less

Optimizing use of the structural chemical analyser (variable pressure FESEM-EDX Raman spectroscopy) on micro-size complex historical paintings characterization.

PubMed

Guerra, I; Cardell, C

2015-10-01

The novel Structural Chemical Analyser (hyphenated Raman spectroscopy and scanning electron microscopy equipped with an X-ray detector) is gaining popularity since it allows 3-D morphological studies and elemental, molecular, structural and electronic analyses of a single complex micro-sized sample without transfer between instruments. However, its full potential remains unexploited in painting heritage where simultaneous identification of inorganic and organic materials in paintings is critically yet unresolved. Despite benefits and drawbacks shown in literature, new challenges have to be faced analysing multifaceted paint specimens. SEM-Structural Chemical Analyser systems differ since they are fabricated ad hoc by request. As configuration influences the procedure to optimize analyses, likewise analytical protocols have to be designed ad hoc. This paper deals with the optimization of the analytical procedure of a Variable Pressure Field Emission scanning electron microscopy equipped with an X-ray detector Raman spectroscopy system to analyse historical paint samples. We address essential parameters, technical challenges and limitations raised from analysing paint stratigraphies, archaeological samples and loose pigments. We show that accurate data interpretation requires comprehensive knowledge of factors affecting Raman spectra. We tackled: (i) the in-FESEM-Raman spectroscopy analytical sequence, (ii) correlations between FESEM and Structural Chemical Analyser/laser analytical position, (iii) Raman signal intensity under different VP-FESEM vacuum modes, (iv) carbon deposition on samples under FESEM low-vacuum mode, (v) crystal nature and morphology, (vi) depth of focus and (vii) surface-enhanced Raman scattering effect. We recommend careful planning of analysis strategies prior to research which, although time consuming, guarantees reliable results. The ultimate goal of this paper is to help to guide future users of a FESEM-Structural Chemical Analyser system in order to increase applications. © 2015 The Authors Journal of Microscopy © 2015 Royal Microscopical Society.

How well can body size represent effects of the environment on demographic rates? Disentangling correlated explanatory variables.

PubMed

Brooks, Mollie E; Mugabo, Marianne; Rodgers, Gwendolen M; Benton, Timothy G; Ozgul, Arpat

2016-03-01

Demographic rates are shaped by the interaction of past and current environments that individuals in a population experience. Past environments shape individual states via selection and plasticity, and fitness-related traits (e.g. individual size) are commonly used in demographic analyses to represent the effect of past environments on demographic rates. We quantified how well the size of individuals captures the effects of a population's past and current environments on demographic rates in a well-studied experimental system of soil mites. We decomposed these interrelated sources of variation with a novel method of multiple regression that is useful for understanding nonlinear relationships between responses and multicollinear explanatory variables. We graphically present the results using area-proportional Venn diagrams. Our novel method was developed by combining existing methods and expanding upon them. We showed that the strength of size as a proxy for the past environment varied widely among vital rates. For instance, in this organism with an income breeding life history, the environment had more effect on reproduction than individual size, but with substantial overlap indicating that size encompassed some of the effects of the past environment on fecundity. This demonstrates that the strength of size as a proxy for the past environment can vary widely among life-history processes within a species, and this variation should be taken into consideration in trait-based demographic or individual-based approaches that focus on phenotypic traits as state variables. Furthermore, the strength of a proxy will depend on what state variable(s) and what demographic rate is being examined; that is, different measures of body size (e.g. length, volume, mass, fat stores) will be better or worse proxies for various life-history processes. © 2016 The Authors. Journal of Animal Ecology © 2016 British Ecological Society.

Sample Size Requirements for Studies of Treatment Effects on Beta-Cell Function in Newly Diagnosed Type 1 Diabetes

PubMed Central

Lachin, John M.; McGee, Paula L.; Greenbaum, Carla J.; Palmer, Jerry; Gottlieb, Peter; Skyler, Jay

2011-01-01

Preservation of -cell function as measured by stimulated C-peptide has recently been accepted as a therapeutic target for subjects with newly diagnosed type 1 diabetes. In recently completed studies conducted by the Type 1 Diabetes Trial Network (TrialNet), repeated 2-hour Mixed Meal Tolerance Tests (MMTT) were obtained for up to 24 months from 156 subjects with up to 3 months duration of type 1 diabetes at the time of study enrollment. These data provide the information needed to more accurately determine the sample size needed for future studies of the effects of new agents on the 2-hour area under the curve (AUC) of the C-peptide values. The natural log(), log(+1) and square-root transformations of the AUC were assessed. In general, a transformation of the data is needed to better satisfy the normality assumptions for commonly used statistical tests. Statistical analysis of the raw and transformed data are provided to estimate the mean levels over time and the residual variation in untreated subjects that allow sample size calculations for future studies at either 12 or 24 months of follow-up and among children 8–12 years of age, adolescents (13–17 years) and adults (18+ years). The sample size needed to detect a given relative (percentage) difference with treatment versus control is greater at 24 months than at 12 months of follow-up, and differs among age categories. Owing to greater residual variation among those 13–17 years of age, a larger sample size is required for this age group. Methods are also described for assessment of sample size for mixtures of subjects among the age categories. Statistical expressions are presented for the presentation of analyses of log(+1) and transformed values in terms of the original units of measurement (pmol/ml). Analyses using different transformations are described for the TrialNet study of masked anti-CD20 (rituximab) versus masked placebo. These results provide the information needed to accurately evaluate the sample size for studies of new agents to preserve C-peptide levels in newly diagnosed type 1 diabetes. PMID:22102862

Sample size requirements for studies of treatment effects on beta-cell function in newly diagnosed type 1 diabetes.

PubMed

Lachin, John M; McGee, Paula L; Greenbaum, Carla J; Palmer, Jerry; Pescovitz, Mark D; Gottlieb, Peter; Skyler, Jay

2011-01-01

Preservation of β-cell function as measured by stimulated C-peptide has recently been accepted as a therapeutic target for subjects with newly diagnosed type 1 diabetes. In recently completed studies conducted by the Type 1 Diabetes Trial Network (TrialNet), repeated 2-hour Mixed Meal Tolerance Tests (MMTT) were obtained for up to 24 months from 156 subjects with up to 3 months duration of type 1 diabetes at the time of study enrollment. These data provide the information needed to more accurately determine the sample size needed for future studies of the effects of new agents on the 2-hour area under the curve (AUC) of the C-peptide values. The natural log(x), log(x+1) and square-root (√x) transformations of the AUC were assessed. In general, a transformation of the data is needed to better satisfy the normality assumptions for commonly used statistical tests. Statistical analysis of the raw and transformed data are provided to estimate the mean levels over time and the residual variation in untreated subjects that allow sample size calculations for future studies at either 12 or 24 months of follow-up and among children 8-12 years of age, adolescents (13-17 years) and adults (18+ years). The sample size needed to detect a given relative (percentage) difference with treatment versus control is greater at 24 months than at 12 months of follow-up, and differs among age categories. Owing to greater residual variation among those 13-17 years of age, a larger sample size is required for this age group. Methods are also described for assessment of sample size for mixtures of subjects among the age categories. Statistical expressions are presented for the presentation of analyses of log(x+1) and √x transformed values in terms of the original units of measurement (pmol/ml). Analyses using different transformations are described for the TrialNet study of masked anti-CD20 (rituximab) versus masked placebo. These results provide the information needed to accurately evaluate the sample size for studies of new agents to preserve C-peptide levels in newly diagnosed type 1 diabetes.

Efficacy and Safety of Augmenting the Preclose Technique with a Collagen-Based Closure Device for Percutaneous Endovascular Aneurysm Repair

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

Patel, Rafiuddin, E-mail: rafiuddin.patel@ouh.nhs.uk; Juszczak, Maciej T.; Bratby, Mark J.

PurposeTo report our experience of selectively augmenting the preclose technique for percutaneous endovascular aneurysm repair (p-EVAR) with an Angio-Seal device as a haemostatic adjunct in cases of significant bleeding after tensioning the sutures of the suture-mediated closure devices.Materials and MethodsProspectively collected data for p-EVAR patients at our institute were analysed. Outcomes included technical success and access site complications. A logistic regression model was used to analyse the effects of sheath size, CFA features and stent graft type on primary failure of the preclose technique necessitating augmentation and also on the development of complications.Resultsp-EVAR was attempted via 122 CFA access sitesmore » with a median sheath size of 18-French (range 12- to 28-French). Primary success of the preclose technique was 75.4 % (92/122). Angio-Seal augmentation was utilised as an adjunct to the preclose technique in 20.5 % (25/122). The overall p-EVAR success rate was 95.1 % (116/122). There was a statistically significant relationship (p = 0.0093) between depth of CFA and primary failure of preclose technique. CFA diameter, calcification, type of stent graft and sheath size did not have significant effects on primary preclose technique failure. Overall 4.9 % (6/122) required surgical conversion but otherwise there were no major complications.ConclusionAugmentation with an Angio-Seal device is a safe and effective adjunct to increase the success rate of the preclose technique in p-EVAR.« less

How self-reported hot flashes may relate to affect, cognitive performance and sleep.

PubMed

Regestein, Quentin; Friebely, Joan; Schiff, Isaac

2015-08-01

To explain the controversy about whether midlife women who self-report hot flashes have relatively increased affective symptoms, poor cognitive performance or worse sleep. Retrospective data from 88 women seeking relief from bothersome day and night hot flashes were submitted to mixed linear regression modeling to find if estimated hot flashes, as measured by Women's Health Questionnaire (WHQ) items, or diary-documented hot flashes recorded daily, were associated with each other, or with affective, cognitive or sleep measures. Subjects averaged 6.3 daytime diary-documented hot flashes and 2.4 nighttime diary-documented hot flashes per 24h. Confounder-controlled diary-documented hot flashes but not estimated hot flashes were associated with increased Leeds anxiety scores (F=4.9; t=2.8; p=0.01) and Leeds depression scores (3.4; 2.5; 0.02), decreased Stroop Color-Word test performance (9.4; 3.5; 0.001), increased subjective sleep disturbance (effect size=0.83) and increased objective sleep disturbance (effect size=0.35). Hot flash effects were small to moderate in size. Univariate but not multivariate analyses revealed that all hot flash measures were associated with all affect measures. Different measures of hot flashes associated differently with affect, cognition and sleep. Only nighttime diary-document hot flash consistently correlated with any affect measures in multivariate analyses. The use of differing measures for hot flashes, affect, cognition and sleep may account for the continually reported inconsistencies in menopause study outcomes. This problem impedes forging a consensus on whether hot flashes correlate with neuropsychological symptoms. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Reduction of a metapopulation genetic model to an effective one-island model

NASA Astrophysics Data System (ADS)

Parra-Rojas, César; McKane, Alan J.

2018-04-01

We explore a model of metapopulation genetics which is based on a more ecologically motivated approach than is frequently used in population genetics. The size of the population is regulated by competition between individuals, rather than by artificially imposing a fixed population size. The increased complexity of the model is managed by employing techniques often used in the physical sciences, namely exploiting time-scale separation to eliminate fast variables and then constructing an effective model from the slow modes. We analyse this effective model and show that the predictions for the probability of fixation of the alleles and the mean time to fixation agree well with those found from numerical simulations of the original model. Contribution to the Focus Issue Evolutionary Modeling and Experimental Evolution edited by José Cuesta, Joachim Krug and Susanna Manrubia.

The intellectual profile of abused and neglected children in the Philippines: An analysis of SB5 IQ scores of sexually abused, physically abused and neglected children.

PubMed

Bengwasan, Peejay D

2018-05-24

Child abuse and neglect have been associated with cognitive deficits, among other effects on child development. This study explores the prediction that child abuse and neglect has an impact on Stanford-Binet Intelligence Scales 5th Edition (SB5) IQ scores, in relation to gender, age and type of abuse experienced. 300 children with experiences of abuse and neglect were included in the study, comprising 100 sexually abused, 100 physically abused and 100 neglected children. Overall, all scores on the SB5 were found to be significantly lower than the minimum average scores on the test. Verbal IQ (VIQ) scores were likewise found to be significantly lower than Nonverbal IQ (NVIQ) scores. Full Scale IQ (FSIQ) scores did not reveal heterogeneity when gender was factored in. Age and type of abuse (with a moderate effect size) on the other hand, showed significant differences among groups. Statistical analyses of SB5 Factor Index Scores revealed that abused children, in general, have significantly higher Visual-Spatial Processing (VS) and Quantitative Reasoning (QR) scores and lower scores in Knowledge (KN). There was a large effect size found in such an analysis. Age (with a large effect size), gender and type of abuse (with moderate effect sizes) give significant variations to this obtained profile. Copyright © 2018 Elsevier Ltd. All rights reserved.

Discovering human germ cell mutagens with whole genome sequencing: Insights from power calculations reveal the importance of controlling for between-family variability.

PubMed

Webster, R J; Williams, A; Marchetti, F; Yauk, C L

2018-07-01

Mutations in germ cells pose potential genetic risks to offspring. However, de novo mutations are rare events that are spread across the genome and are difficult to detect. Thus, studies in this area have generally been under-powered, and no human germ cell mutagen has been identified. Whole Genome Sequencing (WGS) of human pedigrees has been proposed as an approach to overcome these technical and statistical challenges. WGS enables analysis of a much wider breadth of the genome than traditional approaches. Here, we performed power analyses to determine the feasibility of using WGS in human families to identify germ cell mutagens. Different statistical models were compared in the power analyses (ANOVA and multiple regression for one-child families, and mixed effect model sampling between two to four siblings per family). Assumptions were made based on parameters from the existing literature, such as the mutation-by-paternal age effect. We explored two scenarios: a constant effect due to an exposure that occurred in the past, and an accumulating effect where the exposure is continuing. Our analysis revealed the importance of modeling inter-family variability of the mutation-by-paternal age effect. Statistical power was improved by models accounting for the family-to-family variability. Our power analyses suggest that sufficient statistical power can be attained with 4-28 four-sibling families per treatment group, when the increase in mutations ranges from 40 to 10% respectively. Modeling family variability using mixed effect models provided a reduction in sample size compared to a multiple regression approach. Much larger sample sizes were required to detect an interaction effect between environmental exposures and paternal age. These findings inform study design and statistical modeling approaches to improve power and reduce sequencing costs for future studies in this area. Crown Copyright © 2018. Published by Elsevier B.V. All rights reserved.

Computational Modelling and Optimal Control of Ebola Virus Disease with non-Linear Incidence Rate

NASA Astrophysics Data System (ADS)

Takaidza, I.; Makinde, O. D.; Okosun, O. K.

2017-03-01

The 2014 Ebola outbreak in West Africa has exposed the need to connect modellers and those with relevant data as pivotal to better understanding of how the disease spreads and quantifying the effects of possible interventions. In this paper, we model and analyse the Ebola virus disease with non-linear incidence rate. The epidemic model created is used to describe how the Ebola virus could potentially evolve in a population. We perform an uncertainty analysis of the basic reproductive number R 0 to quantify its sensitivity to other disease-related parameters. We also analyse the sensitivity of the final epidemic size to the time control interventions (education, vaccination, quarantine and safe handling) and provide the cost effective combination of the interventions.

Effect of sulfate and carbonate minerals on particle-size distributions in arid soils

USGS Publications Warehouse

Goossens, Dirk; Buck, Brenda J.; Teng, Yuazxin; Robins, Colin; Goldstein, Harland L.

2014-01-01

Arid soils pose unique problems during measurement and interpretation of particle-size distributions (PSDs) because they often contain high concentrations of water-soluble salts. This study investigates the effects of sulfate and carbonate minerals on grain-size analysis by comparing analyses in water, in which the minerals dissolve, and isopropanol (IPA), in which they do not. The presence of gypsum, in particular, substantially affects particle-size analysis once the concentration of gypsum in the sample exceeds the mineral’s solubility threshold. For smaller concentrations particle-size results are unaffected. This is because at concentrations above the solubility threshold fine particles cement together or bind to coarser particles or aggregates already present in the sample, or soluble mineral coatings enlarge grains. Formation of discrete crystallites exacerbates the problem. When soluble minerals are dissolved the original, insoluble grains will become partly or entirely liberated. Thus, removing soluble minerals will result in an increase in measured fine particles. Distortion of particle-size analysis is larger for sulfate minerals than for carbonate minerals because of the much higher solubility in water of the former. When possible, arid soils should be analyzed using a liquid in which the mineral grains do not dissolve, such as IPA, because the results will more accurately reflect the PSD under most arid soil field conditions. This is especially important when interpreting soil and environmental processes affected by particle size.

Meta-analysis of workplace physical activity interventions.

PubMed

Conn, Vicki S; Hafdahl, Adam R; Cooper, Pamela S; Brown, Lori M; Lusk, Sally L

2009-10-01

Most adults do not achieve adequate physical activity levels. Despite the potential benefits of worksite health promotion, no previous comprehensive meta-analysis has summarized health and physical activity behavior outcomes from such programs. This comprehensive meta-analysis integrated the extant wide range of worksite physical activity intervention research. Extensive searching located published and unpublished intervention studies reported from 1969 through 2007. Results were coded from primary studies. Random-effects meta-analytic procedures, including moderator analyses, were completed in 2008. Effects on most variables were substantially heterogeneous because diverse studies were included. Standardized mean difference (d) effect sizes were synthesized across approximately 38,231 subjects. Significantly positive effects were observed for physical activity behavior (0.21); fitness (0.57); lipids (0.13); anthropometric measures (0.08); work attendance (0.19); and job stress (0.33). The significant effect size for diabetes risk (0.98) is less robust given small sample sizes. The mean effect size for fitness corresponds to a difference between treatment minus control subjects' means on VO2max of 3.5 mL/kg/min; for lipids, -0.2 on the ratio of total cholesterol to high-density lipoprotein; and for diabetes risk, -12.6 mg/dL on fasting glucose. These findings document that some workplace physical activity interventions can improve both health and important worksite outcomes. Effects were variable for most outcomes, reflecting the diversity of primary studies. Future primary research should compare interventions to confirm causal relationships and further explore heterogeneity.

The efficacy of cognitive behavioral therapy for Chinese people: A meta-analysis.

PubMed

Ng, Ting Kin; Wong, Daniel Fu Keung

2018-07-01

Over the past decade, cognitive behavioral therapy has been applied to an increasingly wider range of disorders and problems in Chinese societies. However, no meta-analysis has been conducted to synthesize the studies on cognitive behavioral therapy for Chinese clients. The purpose of this meta-analytic study was to examine the overall efficacy of cognitive behavioral therapy for Chinese people. A literature search was conducted using electronic databases, including Web of Science, PsycINFO and PubMed. Pooled mean effect sizes were calculated using the random-effects model. The literature search identified 55 studies with 6763 Chinese participants. The overall short-term effect of cognitive behavioral therapy on the primary outcome was medium in size. Effect sizes were medium for anxiety, depression/well-being and caregiving stress and small for psychotic symptoms and addictive behaviors. The effects of cognitive behavioral therapy on process variables, dysfunctional thoughts and coping, were in the small range. The overall longer-term effect of cognitive behavioral therapy on the primary outcome was medium in size. Moderator analyses showed that the short-term effect was stronger for culturally adapted cognitive behavioral therapy than for unadapted cognitive behavioral therapy. Type of primary outcome, type of control group, recruitment method, study design, the format of delivery and region were found to moderate the efficacy of cognitive behavioral therapy. The findings of this study provide evidence for the overall efficacy of cognitive behavioral therapy for Chinese people and the benefit of cultural adaptation of cognitive behavioral therapy to Chinese culture.

A multigenerational effect of parental age on offspring size but not fitness in common duckweed (Lemna minor).

PubMed

Barks, P M; Laird, R A

2016-04-01

Classic theories on the evolution of senescence make the simplifying assumption that all offspring are of equal quality, so that demographic senescence only manifests through declining rates of survival or fecundity. However, there is now evidence that, in addition to declining rates of survival and fecundity, many organisms are subject to age-related declines in the quality of offspring produced (i.e. parental age effects). Recent modelling approaches allow for the incorporation of parental age effects into classic demographic analyses, assuming that such effects are limited to a single generation. Does this 'single-generation' assumption hold? To find out, we conducted a laboratory study with the aquatic plant Lemna minor, a species for which parental age effects have been demonstrated previously. We compared the size and fitness of 423 laboratory-cultured plants (asexually derived ramets) representing various birth orders, and ancestral 'birth-order genealogies'. We found that offspring size and fitness both declined with increasing 'immediate' birth order (i.e. birth order with respect to the immediate parent), but only offspring size was affected by ancestral birth order. Thus, the assumption that parental age effects on offspring fitness are limited to a single generation does in fact hold for L. minor. This result will guide theorists aiming to refine and generalize modelling approaches that incorporate parental age effects into evolutionary theory on senescence. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

A Meta-Analysis on Antecedents and Outcomes of Detachment from Work.

PubMed

Wendsche, Johannes; Lohmann-Haislah, Andrea

2016-01-01

Detachment from work has been proposed as an important non-work experience helping employees to recover from work demands. This meta-analysis (86 publications, k = 91 independent study samples, N = 38,124 employees) examined core antecedents and outcomes of detachment in employee samples. With regard to outcomes, results indicated average positive correlations between detachment and self-reported mental (i.e., less exhaustion, higher life satisfaction, more well-being, better sleep) and physical (i.e., lower physical discomfort) health, state well-being (i.e., less fatigue, higher positive affect, more intensive state of recovery), and task performance (small to medium sized effects). However, average relationships between detachment and physiological stress indicators and work motivation were not significant while associations with contextual performance and creativity were significant, but negative. Concerning work characteristics, as expected, job demands were negatively related and job resources were positively related to detachment (small sized effects). Further, analyses revealed that person characteristics such as negative affectivity/neuroticism (small sized effect) and heavy work investment (medium sized effect) were negatively related to detachment whereas detachment and demographic variables (i.e., age and gender) were not related. Moreover, we found a medium sized average negative relationship between engagement in work-related activities during non-work time and detachment. For most of the examined relationships heterogeneity of effect sizes was moderate to high. We identified study design, samples' gender distribution, and affective valence of work-related thoughts as moderators for some of these aforementioned relationships. The results of this meta-analysis point to detachment as a non-work (recovery) experience that is influenced by work-related and personal characteristics which in turn is relevant for a range of employee outcomes.

A Meta-Analysis on Antecedents and Outcomes of Detachment from Work

PubMed Central

Wendsche, Johannes; Lohmann-Haislah, Andrea

2017-01-01

Detachment from work has been proposed as an important non-work experience helping employees to recover from work demands. This meta-analysis (86 publications, k = 91 independent study samples, N = 38,124 employees) examined core antecedents and outcomes of detachment in employee samples. With regard to outcomes, results indicated average positive correlations between detachment and self-reported mental (i.e., less exhaustion, higher life satisfaction, more well-being, better sleep) and physical (i.e., lower physical discomfort) health, state well-being (i.e., less fatigue, higher positive affect, more intensive state of recovery), and task performance (small to medium sized effects). However, average relationships between detachment and physiological stress indicators and work motivation were not significant while associations with contextual performance and creativity were significant, but negative. Concerning work characteristics, as expected, job demands were negatively related and job resources were positively related to detachment (small sized effects). Further, analyses revealed that person characteristics such as negative affectivity/neuroticism (small sized effect) and heavy work investment (medium sized effect) were negatively related to detachment whereas detachment and demographic variables (i.e., age and gender) were not related. Moreover, we found a medium sized average negative relationship between engagement in work-related activities during non-work time and detachment. For most of the examined relationships heterogeneity of effect sizes was moderate to high. We identified study design, samples' gender distribution, and affective valence of work-related thoughts as moderators for some of these aforementioned relationships. The results of this meta-analysis point to detachment as a non-work (recovery) experience that is influenced by work-related and personal characteristics which in turn is relevant for a range of employee outcomes. PMID:28133454

Maintenance of phenotypic variation: Repeatability, heritability and size-dependent processes in a wild brook trout population

USGS Publications Warehouse

Letcher, B.H.; Coombs, J.A.; Nislow, K.H.

2011-01-01

Phenotypic variation in body size can result from within-cohort variation in birth dates, among-individual growth variation and size-selective processes. We explore the relative effects of these processes on the maintenance of wide observed body size variation in stream-dwelling brook trout (Salvelinus fontinalis). Based on the analyses of multiple recaptures of individual fish, it appears that size distributions are largely determined by the maintenance of early size variation. We found no evidence for size-dependent compensatory growth (which would reduce size variation) and found no indication that size-dependent survival substantially influenced body size distributions. Depensatory growth (faster growth by larger individuals) reinforced early size variation, but was relatively strong only during the first sampling interval (age-0, fall). Maternal decisions on the timing and location of spawning could have a major influence on early, and as our results suggest, later (>age-0) size distributions. If this is the case, our estimates of heritability of body size (body length=0.25) will be dominated by processes that generate and maintain early size differences. As a result, evolutionary responses to environmental change that are mediated by body size may be largely expressed via changes in the timing and location of reproduction. Published 2011. This article is a US Government work and is in the public domain in the USA.

Using e-mail recruitment and an online questionnaire to establish effect size: A worked example.

PubMed

Kirkby, Helen M; Wilson, Sue; Calvert, Melanie; Draper, Heather

2011-06-09

Sample size calculations require effect size estimations. Sometimes, effect size estimations and standard deviation may not be readily available, particularly if efficacy is unknown because the intervention is new or developing, or the trial targets a new population. In such cases, one way to estimate the effect size is to gather expert opinion. This paper reports the use of a simple strategy to gather expert opinion to estimate a suitable effect size to use in a sample size calculation. Researchers involved in the design and analysis of clinical trials were identified at the University of Birmingham and via the MRC Hubs for Trials Methodology Research. An email invited them to participate.An online questionnaire was developed using the free online tool 'Survey Monkey©'. The questionnaire described an intervention, an electronic participant information sheet (e-PIS), which may increase recruitment rates to a trial. Respondents were asked how much they would need to see recruitment rates increased by, based on 90%. 70%, 50% and 30% baseline rates, (in a hypothetical study) before they would consider using an e-PIS in their research.Analyses comprised simple descriptive statistics. The invitation to participate was sent to 122 people; 7 responded to say they were not involved in trial design and could not complete the questionnaire, 64 attempted it, 26 failed to complete it. Thirty-eight people completed the questionnaire and were included in the analysis (response rate 33%; 38/115). Of those who completed the questionnaire 44.7% (17/38) were at the academic grade of research fellow 26.3% (10/38) senior research fellow, and 28.9% (11/38) professor. Dependent upon the baseline recruitment rates presented in the questionnaire, participants wanted recruitment rate to increase from 6.9% to 28.9% before they would consider using the intervention. This paper has shown that in situations where effect size estimations cannot be collected from previous research, opinions from researchers and trialists can be quickly and easily collected by conducting a simple study using email recruitment and an online questionnaire. The results collected from the survey were successfully used in sample size calculations for a PhD research study protocol.

Effectiveness of regional DTI measures in distinguishing Alzheimer's disease, MCI, and normal aging☆

PubMed Central

Nir, Talia M.; Jahanshad, Neda; Villalon-Reina, Julio E.; Toga, Arthur W.; Jack, Clifford R.; Weiner, Michael W.; Thompson, Paul M.

2013-01-01

The Alzheimer's Disease Neuroimaging Initiative (ADNI) recently added diffusion tensor imaging (DTI), among several other new imaging modalities, in an effort to identify sensitive biomarkers of Alzheimer's disease (AD). While anatomical MRI is the main structural neuroimaging method used in most AD studies and clinical trials, DTI is sensitive to microscopic white matter (WM) changes not detectable with standard MRI, offering additional markers of neurodegeneration. Prior DTI studies of AD report lower fractional anisotropy (FA), and increased mean, axial, and radial diffusivity (MD, AxD, RD) throughout WM. Here we assessed which DTI measures may best identify differences among AD, mild cognitive impairment (MCI), and cognitively healthy elderly control (NC) groups, in region of interest (ROI) and voxel-based analyses of 155 ADNI participants (mean age: 73.5 ± 7.4; 90 M/65 F; 44 NC, 88 MCI, 23 AD). Both VBA and ROI analyses revealed widespread group differences in FA and all diffusivity measures. DTI maps were strongly correlated with widely-used clinical ratings (MMSE, CDR-sob, and ADAS-cog). When effect sizes were ranked, FA analyses were least sensitive for picking up group differences. Diffusivity measures could detect more subtle MCI differences, where FA could not. ROIs showing strongest group differentiation (lowest p-values) included tracts that pass through the temporal lobe, and posterior brain regions. The left hippocampal component of the cingulum showed consistently high effect sizes for distinguishing groups, across all diffusivity and anisotropy measures, and in correlations with cognitive scores. PMID:24179862

The global effect of maternal education on complete childhood vaccination: a systematic review and meta-analysis.

PubMed

Forshaw, Jennifer; Gerver, Sarah M; Gill, Moneet; Cooper, Emily; Manikam, Logan; Ward, Helen

2017-12-28

There is an established correlation between maternal education and reduction in childhood mortality. One proposed link is that an increase in maternal education will lead to an increase in health care access and vaccine uptake. Vaccinations are a central preventative child health tool, therefore demonstrating the importance of understanding factors that can improve coverage. This review aims to establish if there is a correlation between increasing maternal education and vaccine uptake and if this varies between continents, setting and time. An electronic database search was conducted using Medline Ovid, Embase and The Cochrane Library using a combination of keywords and appropriate MeSH terms for maternal education and child vaccination. Bibliographies were also hand searched. Data was extracted and entered onto a Microsoft Excel spreadsheet and analysed using STATA 13.0 software. The primary outcome of effect size of maternal education on completion of childhood vaccinations was analysed at different levels. Secondary outcomes were explored using subgroup analyses of differences between continents, rural or urban settings, and dates. The online search yielded 3430 papers, 37 were included in this study. The analysis showed increasing child vaccination uptake with increasing maternal education. Overall, analysis showed that the odds of full childhood vaccination were 2.3 times greater in children whose mother received secondary or higher education when compared to children whose mother had no education. There was large variability in the effect size between the studies included. Improving maternal education is important for increasing childhood vaccination uptake and coverage. Further research is needed in higher income countries. PROSPERO Registration No: CRD42016042409 .

The effect of machine learning regression algorithms and sample size on individualized behavioral prediction with functional connectivity features.

PubMed

Cui, Zaixu; Gong, Gaolang

2018-06-02

Individualized behavioral/cognitive prediction using machine learning (ML) regression approaches is becoming increasingly applied. The specific ML regression algorithm and sample size are two key factors that non-trivially influence prediction accuracies. However, the effects of the ML regression algorithm and sample size on individualized behavioral/cognitive prediction performance have not been comprehensively assessed. To address this issue, the present study included six commonly used ML regression algorithms: ordinary least squares (OLS) regression, least absolute shrinkage and selection operator (LASSO) regression, ridge regression, elastic-net regression, linear support vector regression (LSVR), and relevance vector regression (RVR), to perform specific behavioral/cognitive predictions based on different sample sizes. Specifically, the publicly available resting-state functional MRI (rs-fMRI) dataset from the Human Connectome Project (HCP) was used, and whole-brain resting-state functional connectivity (rsFC) or rsFC strength (rsFCS) were extracted as prediction features. Twenty-five sample sizes (ranged from 20 to 700) were studied by sub-sampling from the entire HCP cohort. The analyses showed that rsFC-based LASSO regression performed remarkably worse than the other algorithms, and rsFCS-based OLS regression performed markedly worse than the other algorithms. Regardless of the algorithm and feature type, both the prediction accuracy and its stability exponentially increased with increasing sample size. The specific patterns of the observed algorithm and sample size effects were well replicated in the prediction using re-testing fMRI data, data processed by different imaging preprocessing schemes, and different behavioral/cognitive scores, thus indicating excellent robustness/generalization of the effects. The current findings provide critical insight into how the selected ML regression algorithm and sample size influence individualized predictions of behavior/cognition and offer important guidance for choosing the ML regression algorithm or sample size in relevant investigations. Copyright © 2018 Elsevier Inc. All rights reserved.

A critical look at spatial scale choices in satellite-based aerosol indirect effect studies

NASA Astrophysics Data System (ADS)

Grandey, B. S.; Stier, P.

2010-06-01

Analysing satellite datasets over large regions may introduce spurious relationships between aerosol and cloud properties due to spatial variations in aerosol type, cloud regime and synoptic regime climatologies. Using MODerate resolution Imaging Spectroradiometer data, we calculate relationships between aerosol optical depth τa, derived liquid cloud droplet effective number concentration Ne and liquid cloud droplet effective radius re at different spatial scales. Generally, positive values of dlnNe dlnτa are found for ocean regions, whilst negative values occur for many land regions. The spatial distribution of dlnre dlnτa shows approximately the opposite pattern, with generally postive values for land regions and negative values for ocean regions. We find that for region sizes larger than 4°×4°, spurious spatial variations in retrieved cloud and aerosol properties can introduce widespread significant errors to calculations of dlnNe dlnτa and dlnre dlnτa . For regions on the scale of 60°×60°, these methodological errors may lead to an overestimate in global cloud albedo effect radiative forcing of order 80%.

Placebo Response in Repetitive Transcranial Magnetic Stimulation Trials of Treatment of Auditory Hallucinations in Schizophrenia: A Meta-Analysis

PubMed Central

Dollfus, Sonia; Lecardeur, Laurent; Morello, Rémy; Etard, Olivier

2016-01-01

Several meta-analyses have assessed the response of patients with schizophrenia with auditory verbal hallucinations (AVH) to treatment with repetitive transcranial magnetic stimulation (rTMS); however, the placebo response has never been explored. Typically observed in a therapeutic trial, the placebo effect may have a major influence on the effectiveness of rTMS. The purpose of this meta-analysis is to evaluate the magnitude of the placebo effect observed in controlled studies of rTMS treatment of AVH, and to determine factors that can impact the magnitude of this placebo effect, such as study design considerations and the type of sham used. The study included twenty-one articles concerning 303 patients treated by sham rTMS. A meta-analytic method was applied to obtain a combined, weighted effect size, Hedges’s g. The mean weighted effect size of the placebo effect across these 21 studies was 0.29 (P < .001). Comparison of the parallel and crossover studies revealed distinct results for each study design; placebo has a significant effect size in the 13 parallel studies (g = 0.44, P < 10−4), but not in the 8 crossover studies (g = 0.06, P = .52). In meta-analysis of the 13 parallel studies, the 45° position coil showed the highest effect size. Our results demonstrate that placebo effect should be considered a major source of bias in the assessment of rTMS efficacy. These results fundamentally inform the design of further controlled studies, particularly with respect to studies of rTMS treatment in psychiatry. PMID:26089351

Effects of size and surface of zinc oxide and aluminum-doped zinc oxide nanoparticles on cell viability inferred by proteomic analyses.

PubMed

Pan, Chih-Hong; Liu, Wen-Te; Bien, Mauo-Ying; Lin, I-Chan; Hsiao, Ta-Chih; Ma, Chih-Ming; Lai, Ching-Huang; Chen, Mei-Chieh; Chuang, Kai-Jen; Chuang, Hsiao-Chi

2014-01-01

Although the health effects of zinc oxide nanoparticles (ZnONPs) on the respiratory system have been reported, the fate, potential toxicity, and mechanisms in biological cells of these particles, as related to particle size and surface characteristics, have not been well elucidated. To determine the physicochemical properties of ZnONPs that govern cytotoxicity, we investigated the effects of size, electronic properties, zinc concentration, and pH on cell viability using human alveolar-basal epithelial A549 cells as a model. We observed that a 2-hour or longer exposure to ZnONPs induced changes in cell viability. The alteration in cell viability was associated with the zeta potentials and pH values of the ZnONPs. Proteomic profiling of A549 exposed to ZnONPs for 2 and 4 hours was used to determine the biological mechanisms of ZnONP toxicity. p53-pathway activation was the core mechanism regulating cell viability in response to particle size. Activation of the Wnt and TGFβ signaling pathways was also important in the cellular response to ZnONPs of different sizes. The cadherin and Wnt signaling pathways were important cellular mechanisms triggered by surface differences. These results suggested that the size and surface characteristics of ZnONPs might play an important role in their observed cytotoxicity. This approach facilitates the design of more comprehensive systems for the evaluation of nanoparticles.

Does body size affect a bird's sensitivity to patch size and landscape structure?

USGS Publications Warehouse

Winter, Maiken; Johnson, Douglas H.; Shaffer, Jill A.

2006-01-01

Larger birds are generally more strongly affected by habitat loss and fragmentation than are smaller ones because they require more resources and thus larger habitat patches. Consequently, conservation actions often favor the creation or protection of larger over smaller patches. However, in grassland systems the boundaries between a patch and the surrounding landscape, and thus the perceived size of a patch, can be indistinct. We investigated whether eight grassland bird species with different body sizes perceived variation in patch size and landscape structure in a consistent manner. Data were collected from surveys conducted in 44 patches of northern tallgrass prairie during 1998–2001. The response to patch size was very similar among species regardless of body size (density was little affected by patch size), except in the Greater Prairie-Chicken (Tympanuchus cupido), which showed a threshold effect and was not found in patches smaller than 140 ha. In landscapes containing 0%–30% woody vegetation, smaller species responded more negatively to increases in the percentage of woody vegetation than larger species, but above an apparent threshold of 30%, larger species were not detected. Further analyses revealed that the observed variation in responses to patch size and landscape structure among species was not solely due to body size per se, but to other differences among species. These results indicate that a stringent application of concepts requiring larger habitat patches for larger species appears to limit the number of grassland habitats that can be protected and may not always be the most effective conservation strategy.

On the absence of a correlation between population size and 'toolkit size' in ethnographic hunter-gatherers.

PubMed

Aoki, Kenichi

2018-04-05

In apparent contradiction to the theoretically predicted effect of population size on the quality/quantity of material culture, statistical analyses on ethnographic hunter-gatherers have shown an absence of correlation between population size and toolkit size. This has sparked a heated, if sometimes tangential, debate as to the usefulness of the theoretical models and as to what modes of cultural transmission humans are capable of and hunter-gatherers rely on. I review the directly relevant theoretical literature and argue that much of the confusion is caused by a mismatch between the theoretical variable and the empirical observable. I then confirm that a model incorporating the appropriate variable does predict a positive association between population size and toolkit size for random oblique, vertical, best-of- K , conformist, anticonformist, success bias and one-to-many cultural transmission, with the caveat that for all populations sampled, the population size has remained constant and toolkit size has reached the equilibrium for this population size. Finally, I suggest three theoretical scenarios, two of them involving variable population size, that would attenuate or eliminate this association and hence help to explain the empirical absence of correlation.This article is part of the theme issue 'Bridging cultural gaps: interdisciplinary studies in human cultural evolution'. © 2018 The Author(s).

Effect of grain size distribution on stress-strain behavior of lunar soil simulants

NASA Astrophysics Data System (ADS)

Monkul, Mehmet Murat; Dacic, Amina

2017-08-01

Geotechnical behavior of the lunar soils is important for engineering analyses regarding various aspects of the future extraterrestrial settlement plans including lunar exploration and construction. Many lunar soil simulants had been produced so far, in order to resemble lunar soils and conduct such analyses. The goal of this study is to investigate how and to what extent the variations in the grain size distribution of different lunar soil simulants affect their shear strength and volume change behaviors, both of which are quite important for constitutive modeling and geotechnical design. Static simple shear tests were conducted on four lunar soil simulants that were reproduced in terms of original gradation characteristics. The results indicate that various gradational parameters, such as mean grain size, coefficient of uniformity and fines content influence the shear strength, the amount of volumetric dilatancy, and the rate of dilatancy of simulant specimens in different levels when they were compared at the same density or void ratio. The possible reasons behind such different levels of influence were also discussed by focusing on the initial fabric of specimens achieved before shearing and the interaction between silt and sand matrices in the simulants.

Ultrasonic-assisted synthesis of nano lead(II) coordination polymer as precursors for preparation of lead(II) oxide nano-structures: Thermal, optical properties and XRD studies.

PubMed

Ghavidelaghdam, Elham; Shahverdizadeh, Gholam Hossein; Motameni Tabatabai, Javad; Mirtamizdoust, Babak

2018-04-01

Nano structure of a lead (II) coordination polymer [Pb 2 (C 2 Cl 3 O 2 ) 2 (NO 3 ) 2 (C l2 H 8 N 2 ) 2 ] n (1), has been synthesized by a sonochemical method in different concentrations. The nano particles were characterized by scanning electron microscopy (SEM) X-ray powder diffraction (XRD), FT-IR spectroscopy and elemental analyses. The thermal stability of nano structure is closely investigated via thermal gravimetric (TGA), and compared with crystalline structure. The compounds are then heated to 600 °C to produce PbO nano particles. The resulting PbO is characterized through XRD and SEM analyses. Concentration of initial reagents effects on size and morphology of nano-structured compound 1 have been studied and show that low concentrations of initial reagents decreased particles size and leaded to uniform nano particles morphology. The photoluminescence properties of the prepared compound, as crystalline and as nanoparticles, have been investigated. The result showed a good correlation between the size and emission wavelength. Copyright © 2017. Published by Elsevier B.V.

A meta-analysis of the effects of measuring theory of planned behaviour constructs on behaviour within prospective studies.

PubMed

Mankarious, Evon; Kothe, Emily

2015-01-01

Measurement reactivity effects, such as the mere measurement effect, have been proposed as a reason for behavioural changes in a number of theory of planned behaviour intervention studies. However, it is unclear whether such changes are the result of the mere measurement effect or of other artefacts of intervention study design. The aim of this study is to determine the size and direction of changes in health behaviours from baseline to follow-up in prospective studies using the theory of planned behaviour. Electronic databases were searched for the theory of planned behaviour studies which measured health behaviours at two or more time points. Change in behaviour was calculated for all studies. Sixty-six studies were included. Mean effect sizes across all studies were small and negative (d = -.03). Effect size was moderated by behaviour, behaviour type and follow-up length. Subgroup analyses showed significant decreases in socially undesirable behaviour (d = -.28), binge drinking (d = -.17), risk driving (d = -.20), sugar snack consumption (d = -.43) and sun-protective behaviour (d = -.18). Measurement of intention at baseline resulted in significant decreases in undesirable behaviour. Changes in undesirable behaviours reported in other studies may be the result of the mere measurement effect.

Self-referral psychological treatment centre for young adults: a 2-year observational evaluation of routine practice before and after treatment

PubMed Central

Halje, Karin; Timpka, Toomas; Tylestedt, Petra; Adler, Anna-Karin; Fröberg, Lena; Schyman, Tommy; Johansson, Kristoffer; Dahl, Katarina

2015-01-01

Objectives To examine a self-referral psychological service provided to young adults with regard to effects on anxiety, depression and psychological distress and to explore client factors predicting non-adherence and non-response. Design Observational study over a 2-year period. Setting Young Adults Centre providing psychological services by self-referral (preprimary care) to Linköping, Åtvidaberg, and Kinda municipalities (combined population 145 000) in Östergötland county, Sweden. Participants 607 young adults (16–25 years of age); 71% females (n=429). Intervention Individually scheduled cognitive behavioural therapy delivered in up to six 45 min sessions structured according to an assessment of the client's mental health problems: anxiety, depression, anxiety and depression combined, or decreased distress without specific anxiety or depression. Primary outcome measures Pre–post intervention changes in psychological distress (General Health Questionnaire-12, GHQ-12), Hospital Anxiety and Depression Scale Anxiety/Depression (HADS-A/D). Results 192 clients (32.5%) discontinued the intervention on their own initiative and 39 clients (6.6%) were referred to a psychiatric clinic during the course of the intervention. Intention-to-treat analyses including all clients showed a medium treatment effect size (d=0.64) with regard to psychological distress, and small effect sizes were observed with regard to anxiety (d=0.58) and depression (d=0.57). Restricting the analyses to clients who adhered to the agreed programme, a large effect size (d=1.26) was observed with regard to psychological distress, and medium effect sizes were observed with regard to anxiety (d=1.18) and depression (d=1.19). Lower age and a high initial HADS-A score were the strongest risk factors for non-adherence, and inability to concentrate and thinking of oneself as a worthless person increased the risk for discontinuation. Conclusions We conclude that provision of psychological services to young people through a self-referral centre has potential to improve long-term mental health in communities, but management of non-adherence remains a central challenge. PMID:26283666

The Influence of Judgment Calls on Meta-Analytic Findings.

PubMed

Tarrahi, Farid; Eisend, Martin

2016-01-01

Previous research has suggested that judgment calls (i.e., methodological choices made in the process of conducting a meta-analysis) have a strong influence on meta-analytic findings and question their robustness. However, prior research applies case study comparison or reanalysis of a few meta-analyses with a focus on a few selected judgment calls. These studies neglect the fact that different judgment calls are related to each other and simultaneously influence the outcomes of a meta-analysis, and that meta-analytic findings can vary due to non-judgment call differences between meta-analyses (e.g., variations of effects over time). The current study analyzes the influence of 13 judgment calls in 176 meta-analyses in marketing research by applying a multivariate, multilevel meta-meta-analysis. The analysis considers simultaneous influences from different judgment calls on meta-analytic effect sizes and controls for alternative explanations based on non-judgment call differences between meta-analyses. The findings suggest that judgment calls have only a minor influence on meta-analytic findings, whereas non-judgment call differences between meta-analyses are more likely to explain differences in meta-analytic findings. The findings support the robustness of meta-analytic results and conclusions.

Combining moderators to identify clinical profiles of patients who will, and will not, benefit from aripiprazole augmentation for treatment resistant late-life major depressive disorder.

PubMed

Smagula, Stephen F; Wallace, Meredith L; Anderson, Stewart J; Karp, Jordan F; Lenze, Eric J; Mulsant, Benoit H; Butters, Meryl A; Blumberger, Daniel M; Diniz, Breno S; Lotrich, Francis E; Dew, Mary Amanda; Reynolds, Charles F

2016-10-01

Personalizing treatment for late-life depression requires identifying and integrating information from multiple factors that influence treatment efficacy (moderators). We performed exploratory moderator analyses using data from a multi-site, randomized, placebo-controlled, double-blind trial of aripiprazole augmentation. Patients (n = 159) aged ≥60 years had major depressive disorder that failed to remit with venlafaxine monotherapy. We examined effect sizes of 39 potential moderators of aripiprazole (vs. placebo) augmentation efficacy using the outcome of percentage reduction in depressive symptom after 12 weeks. We then incorporated information from the individually relevant variables in combined moderators. A larger aripiprazole treatment effect was related to: white race, better physical function, better performance on Trail-Making, attention, immediate, and delayed memory tests, greater psychomotor agitation and suicidality symptoms, and a history of adequate antidepressant pharmacotherapy. A smaller aripiprazole treatment effect was observed in patients with: more pain and more work/activity impairment and libido symptoms. Combining information from race and Trail-Making test performance (base combined moderator (Mb*)) produced a larger effect size (Spearman effect size = 0.29 (95% confidence interval (CI): 0.15, 0.42)) than any individual moderator. Adding other individually relevant moderators in the full combined moderator (Mf*) further improved effect size (Spearman effect size = 0.39 (95% CI: 0.25, 0.52)) and identified a sub-group benefiting more from placebo plus continuation venlafaxine monotherapy than adjunctive aripiprazole. Combining moderators can help clinicians personalize depression treatment. We found the majority of our patients benefited from adjunctive aripiprazole, but a smaller subgroup that is identifiable using clinical measures appeared to benefit more from continuation venlafaxine plus placebo. Copyright © 2016 Elsevier Ltd. All rights reserved.

Combining moderators to identify clinical profiles of patients who will, and will not, benefit from aripiprazole augmentation for treatment resistant late-life major depressive disorder

PubMed Central

Smagula, Stephen F.; Wallace, Meredith L.; Anderson, Stewart J.; Karp, Jordan F.; Lenze, Eric J.; Mulsant, Benoit H.; Butters, Meryl A.; Blumberger, Daniel M.; Diniz, Breno S.; Lotrich, Francis; Dew, Mary Amanda; Reynolds, Charles F.

2016-01-01

Personalizing treatment for late-life depression requires identifying and integrating information from multiple factors that influence treatment efficacy (moderators). We performed exploratory moderator analyses using data from a multi-site, randomized, placebo-controlled, double-blind trial of aripiprazole augmentation. Patients (n=159) aged ≥60 years had major depressive disorder that failed to remit with venlafaxine monotherapy. We examined effect sizes of 39 potential moderators of aripiprazole (vs. placebo) augmentation efficacy using the outcome of percentage reduction in depressive symptom after 12 weeks. We then incorporated information from the individually relevant variables in combined moderators. A larger aripiprazole treatment effect was related to: white race, better physical function, better performance on Trail-Making, attention, immediate, and delayed memory tests, greater psychomotor agitation and suicidality symptoms, and a history of adequate antidepressant pharmacotherapy. A smaller aripiprazole treatment effect was observed in patients with: more pain and more work/activity impairment and libido symptoms. Combining information from race and Trail-Making test performance (base combined moderator (Mb*)) produced a larger effect size (Spearman effect size=0.29 (95% confidence interval (CI): 0.15, 0.42)) than any individual moderator. Adding other individually relevant moderators in the full combined moderator (Mf*) further improved effect size (Spearman effect size=0.39 (95% CI: 0.25, 0.52)) and identified a sub-group benefiting more from placebo plus continuation venlafaxine monotherapy than adjunctive aripiprazole. Combining moderators can help clinicians personalize depression treatment. We found the majority of our patients benefited from adjunctive aripiprazole, but a smaller subgroup that is identifiable using clinical measures appeared to benefit more from continuation venlafaxine plus placebo. PMID:27438687

The size of an ethno-cultural community as a social determinant of health for Chinese seniors.

PubMed

Chau, Shirley; Lai, Daniel W L

2011-12-01

The present study investigated the link between the sizes of the Chinese community to the health of Chinese seniors in Canada. A secondary data analysis of survey data from a representative sample of 2,272 Chinese older adults aged 55 and over was conducted. Hierarchical regression analyses were performed to assess the effects of the size of Chinese communities in Chinese seniors' health. Chinese seniors residing in the community with a small Chinese population reported better physical and mental health than the Chinese seniors residing in communities with a larger Chinese population. The findings were contrary to expectations that health of Chinese seniors should be higher in cities with large Chinese communities. These findings raise new questions for future investigations into the dynamics and impact of ethnic community size, and the importance of studying intragroup differences within ethno-cultural groups to better understand health disparities in ethnic groups.

On the repeated measures designs and sample sizes for randomized controlled trials.

PubMed

Tango, Toshiro

2016-04-01

For the analysis of longitudinal or repeated measures data, generalized linear mixed-effects models provide a flexible and powerful tool to deal with heterogeneity among subject response profiles. However, the typical statistical design adopted in usual randomized controlled trials is an analysis of covariance type analysis using a pre-defined pair of "pre-post" data, in which pre-(baseline) data are used as a covariate for adjustment together with other covariates. Then, the major design issue is to calculate the sample size or the number of subjects allocated to each treatment group. In this paper, we propose a new repeated measures design and sample size calculations combined with generalized linear mixed-effects models that depend not only on the number of subjects but on the number of repeated measures before and after randomization per subject used for the analysis. The main advantages of the proposed design combined with the generalized linear mixed-effects models are (1) it can easily handle missing data by applying the likelihood-based ignorable analyses under the missing at random assumption and (2) it may lead to a reduction in sample size, compared with the simple pre-post design. The proposed designs and the sample size calculations are illustrated with real data arising from randomized controlled trials. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Rule reversal: Ecogeographical patterns of body size variation in the common treeshrew (Mammalia, Scandentia)

USGS Publications Warehouse

Sargis, Eric J.; Millien, Virginie; Woodman, Neal; Olson, Link E.

2018-01-01

There are a number of ecogeographical “rules” that describe patterns of geographical variation among organisms. The island rule predicts that populations of larger mammals on islands evolve smaller mean body size than their mainland counterparts, whereas smaller‐bodied mammals evolve larger size. Bergmann's rule predicts that populations of a species in colder climates (generally at higher latitudes) have larger mean body sizes than conspecifics in warmer climates (at lower latitudes). These two rules are rarely tested together and neither has been rigorously tested in treeshrews, a clade of small‐bodied mammals in their own order (Scandentia) broadly distributed in mainland Southeast Asia and on islands throughout much of the Sunda Shelf. The common treeshrew, Tupaia glis, is an excellent candidate for study and was used to test these two rules simultaneously for the first time in treeshrews. This species is distributed on the Malay Peninsula and several offshore islands east, west, and south of the mainland. Using craniodental dimensions as a proxy for body size, we investigated how island size, distance from the mainland, and maximum sea depth between the mainland and the islands relate to body size of 13 insular T. glis populations while also controlling for latitude and correlation among variables. We found a strong negative effect of latitude on body size in the common treeshrew, indicating the inverse of Bergmann's rule. We did not detect any overall difference in body size between the island and mainland populations. However, there was an effect of island area and maximum sea depth on body size among island populations. Although there is a strong latitudinal effect on body size, neither Bergmann's rule nor the island rule applies to the common treeshrew. The results of our analyses demonstrate the necessity of assessing multiple variables simultaneously in studies of ecogeographical rules.

Physical activity within a CBT intervention improves coping with pain in traumatized refugees: results of a randomized controlled design.

PubMed

Liedl, Alexandra; Müller, Julia; Morina, Naser; Karl, Anke; Denke, Claudia; Knaevelsrud, Christine

2011-02-01

Many traumatized refugees experience both posttraumatic stress disorder and chronic pain. Based on Mutual Maintenance Theory and the Perpetual Avoidance Model, this study examined the additional effect of physical activity within a biofeedback-based cognitive behavioral therapy (CBT-BF) for traumatized refugees. In a controlled design, 36 patients were randomized into one of three conditions (CBT-BF, CBT-BF with physical activity [CBT-BF+active], and a waiting list control group [WL]). Thirty patients (n=10 in each group) completed the treatment and a follow-up assessment 3 months later. Participants' coping strategies, pain and mental health status, and physiological reactivity were assessed before and after the intervention and at 3-month follow-up. Treatment effects were analyzed using analyses of variance with baseline scores as covariates (ANCOVAs) and the Reliable Change Index. The CBT-BF and CBT-BF+active groups showed improvements in all outcome measures relative to the WL group. The effect sizes for the main outcome measures were higher in the CBT-BF+active group than in the CBT-BF group. Repeated measures analyses of covariance showed significant group effects for coping strategies--in particular, for the "cognitive restructuring" and "counter-activities" subscales as well as a marginally significant group effect for "perceived self-competence"--with the CBT-BF+active group showing more favorable outcomes than the CBT-BF group. Moreover, 60% of participants in the CBT-BF+active group showed clinically reliable intraindividual change in at least one subscale of the pain coping strategies questionnaire, compared with just 30% of participants in the CBT-BF group. Findings of improved coping strategies, larger effect sizes, and higher rates of clinical improvement in the CBT-BF+active group suggest that physical activity adds value to pain management interventions for traumatized refugees. Given the small sample size, however, these preliminary results need replication in a larger trial. Wiley Periodicals, Inc.

Exploring reasons for the observed inconsistent trial reports on intra-articular injections with hyaluronic acid in the treatment of osteoarthritis: Meta-regression analyses of randomized trials.

PubMed

Johansen, Mette; Bahrt, Henriette; Altman, Roy D; Bartels, Else M; Juhl, Carsten B; Bliddal, Henning; Lund, Hans; Christensen, Robin

2016-08-01

The aim was to identify factors explaining inconsistent observations concerning the efficacy of intra-articular hyaluronic acid compared to intra-articular sham/control, or non-intervention control, in patients with symptomatic osteoarthritis, based on randomized clinical trials (RCTs). A systematic review and meta-regression analyses of available randomized trials were conducted. The outcome, pain, was assessed according to a pre-specified hierarchy of potentially available outcomes. Hedges׳s standardized mean difference [SMD (95% CI)] served as effect size. REstricted Maximum Likelihood (REML) mixed-effects models were used to combine study results, and heterogeneity was calculated and interpreted as Tau-squared and I-squared, respectively. Overall, 99 studies (14,804 patients) met the inclusion criteria: Of these, only 71 studies (72%), including 85 comparisons (11,216 patients), had adequate data available for inclusion in the primary meta-analysis. Overall, compared with placebo, intra-articular hyaluronic acid reduced pain with an effect size of -0.39 [-0.47 to -0.31; P < 0.001], combining very heterogeneous trial findings (I(2) = 73%). The three most important covariates in reducing heterogeneity were overall risk of bias, blinding of personnel and trial size, reducing heterogeneity with 26%, 26%, and 25%, respectively (Interaction: P ≤ 0.001). Adjusting for publication/selective outcome reporting bias (by imputing "null effects") in 24 of the comparisons with no data available reduced the combined estimate to -0.30 [-0.36 to -0.23; P < 0.001] still in favor of hyaluronic acid. Based on available trial data, intra-articular hyaluronic acid showed a better effect than intra-articular saline on pain reduction in osteoarthritis. Publication bias and the risk of selective outcome reporting suggest only small clinical effect compared to saline. Copyright © 2016 Elsevier Inc. All rights reserved.

Aggregate size and structure determination of nanomaterials in physiological media: importance of dynamic evolution

NASA Astrophysics Data System (ADS)

Afrooz, A. R. M. Nabiul; Hussain, Saber M.; Saleh, Navid B.

2014-12-01

Most in vitro nanotoxicological assays are performed after 24 h exposure. However, in determining size and shape effect of nanoparticles in toxicity assays, initial characterization data are generally used to describe experimental outcome. The dynamic size and structure of aggregates are typically ignored in these studies. This brief communication reports dynamic evolution of aggregation characteristics of gold nanoparticles. The study finds that gradual increase in aggregate size of gold nanospheres (AuNS) occurs up to 6 h duration; beyond this time period, the aggregation process deviates from gradual to a more abrupt behavior as large networks are formed. Results of the study also show that aggregated clusters possess unique structural conformation depending on nominal diameter of the nanoparticles. The differences in fractal dimensions of the AuNS samples likely occurred due to geometric differences, causing larger packing propensities for smaller sized particles. Both such observations can have profound influence on dosimetry for in vitro nanotoxicity analyses.

Missing heritability in the tails of quantitative traits? A simulation study on the impact of slightly altered true genetic models.

PubMed

Pütter, Carolin; Pechlivanis, Sonali; Nöthen, Markus M; Jöckel, Karl-Heinz; Wichmann, Heinz-Erich; Scherag, André

2011-01-01

Genome-wide association studies have identified robust associations between single nucleotide polymorphisms and complex traits. As the proportion of phenotypic variance explained is still limited for most of the traits, larger and larger meta-analyses are being conducted to detect additional associations. Here we investigate the impact of the study design and the underlying assumption about the true genetic effect in a bimodal mixture situation on the power to detect associations. We performed simulations of quantitative phenotypes analysed by standard linear regression and dichotomized case-control data sets from the extremes of the quantitative trait analysed by standard logistic regression. Using linear regression, markers with an effect in the extremes of the traits were almost undetectable, whereas analysing extremes by case-control design had superior power even for much smaller sample sizes. Two real data examples are provided to support our theoretical findings and to explore our mixture and parameter assumption. Our findings support the idea to re-analyse the available meta-analysis data sets to detect new loci in the extremes. Moreover, our investigation offers an explanation for discrepant findings when analysing quantitative traits in the general population and in the extremes. Copyright © 2011 S. Karger AG, Basel.

Vocabulary Knowledge of Children With Cochlear Implants: A Meta-Analysis

PubMed Central

2016-01-01

This article employs meta-analysis procedures to evaluate whether children with cochlear implants demonstrate lower spoken-language vocabulary knowledge than peers with normal hearing. Of the 754 articles screened and 52 articles coded, 12 articles met predetermined inclusion criteria (with an additional 5 included for one analysis). Effect sizes were calculated for relevant studies and forest plots were used to compare differences between groups of children with normal hearing and children with cochlear implants. Weighted effect size averages for expressive vocabulary measures (g = −11.99; p < .001) and for receptive vocabulary measures (g = −20.33; p < .001) indicated that children with cochlear implants demonstrate lower vocabulary knowledge than children with normal hearing. Additional analyses confirmed the value of comparing vocabulary knowledge of children with hearing loss to a tightly matched (e.g., socioeconomic status-matched) sample. Age of implantation, duration of implantation, and chronological age at testing were not significantly related to magnitude of weighted effect size. Findings from this analysis represent a first step toward resolving discrepancies in the vocabulary knowledge literature. PMID:26712811

Feeding strategy and cannibalism of the Argentine hake Merluccius hubbsi.

PubMed

Ocampo Reinaldo, M; González, R; Romero, M A

2011-12-01

The diet composition and feeding strategy of the Argentine hake Merluccius hubbsi in the San Matías Gulf were analysed in order to use this information for the sustainable management of the fishery. Merluccius hubbsi behaved as an opportunistic predator. Small M. hubbsi consumed planktonic crustaceans, whereas medium and large fish ate numerous prey taxa with low frequency of occurrence and variable specific abundance. Intra- and intercohort cannibalism were detected in all size groups and were particularly significant in large M. hubbsi. Medium-sized M. hubbsi consumed small conspecifics and large-sized M. hubbsi consumed both small and medium M. hubbsi. These results indicate that the removal of large M. hubbsi by fishing may increase the risk of overfishing by two combined effects: a direct effect of recruitment-overfishing and an indirect effect of growth-overfishing through an enhanced cannibalism of medium M. hubbsi on small M. hubbsi. Intra- and intercohort cannibalism and other trophic relationships in the M. hubbsi should therefore be considered explicitly in stock assessment models. © 2011 The Authors. Journal of Fish Biology © 2011 The Fisheries Society of the British Isles.

Publication bias in obesity treatment trials?

PubMed

Allison, D B; Faith, M S; Gorman, B S

1996-10-01

The present investigation examined the extent of publication bias (namely the tendency to publish significant findings and file away non-significant findings) within the obesity treatment literature. Quantitative literature synthesis of four published meta-analyses from the obesity treatment literature. Interventions in these studies included pharmacological, educational, child, and couples treatments. To assess publication bias, several regression procedures (for example weighted least-squares, random-effects multi-level modeling, and robust regression methods) were used to regress effect sizes onto their standard errors, or proxies thereof, within each of the four meta-analysis. A significant positive beta weight in these analyses signified publication bias. There was evidence for publication bias within two of the four published meta-analyses, such that reviews of published studies were likely to overestimate clinical efficacy. The lack of evidence for publication bias within the two other meta-analyses might have been due to insufficient statistical power rather than the absence of selection bias. As in other disciplines, publication bias appears to exist in the obesity treatment literature. Suggestions are offered for managing publication bias once identified or reducing its likelihood in the first place.

A possible explanation for the population size discrepancy in tuna (genus Thunnus) estimated from mitochondrial DNA and microsatellite data.

PubMed

Qiu, Fan; Kitchen, Andrew; Beerli, Peter; Miyamoto, Michael M

2013-02-01

A recent study using both mitochondrial DNA (mtDNA) and microsatellite data reported on a population size discrepancy in the eastern tiger salamander where the effective population size (N(e)) estimate of the former exceeded that of the latter. That study suggested, among other hypotheses, that homoplasy of microsatellite alleles is responsible for the discrepancy. In this investigation, we report 10 new cases of a similar discrepancy in five species of tuna. These cases derive from our Bayesian inferences using data from Pacific Bluefin Tuna (Thunnus orientalis) and Yellowfin Tuna (Thunnus albacares), as well as from published estimates of genetic diversity for additional populations of Yellowfin Tuna and three other tuna species. Phylogenetic character analyses of inferred genealogies of Pacific Bluefin and Yellowfin Tuna reveal similar reduced levels of mtDNA and microsatellite homoplasy. Thus, the discrepancy between inferred population sizes from mtDNA and microsatellite data in tuna is most likely not an artifact of the chosen mutation models used in the microsatellite analyses, but may reflect behavioral differences between the sexes such as female-biased philopatry and male-biased dispersal. This explanation now warrants critical testing with more local populations of tuna and with other animal and plant groups that have different life histories. Copyright © 2012 Elsevier Inc. All rights reserved.

Analyses of microstructural and elastic properties of porous SOFC cathodes based on focused ion beam tomography

NASA Astrophysics Data System (ADS)

Chen, Zhangwei; Wang, Xin; Giuliani, Finn; Atkinson, Alan

2015-01-01

Mechanical properties of porous SOFC electrodes are largely determined by their microstructures. Measurements of the elastic properties and microstructural parameters can be achieved by modelling of the digitally reconstructed 3D volumes based on the real electrode microstructures. However, the reliability of such measurements is greatly dependent on the processing of raw images acquired for reconstruction. In this work, the actual microstructures of La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) cathodes sintered at an elevated temperature were reconstructed based on dual-beam FIB/SEM tomography. Key microstructural and elastic parameters were estimated and correlated. Analyses of their sensitivity to the grayscale threshold value applied in the image segmentation were performed. The important microstructural parameters included porosity, tortuosity, specific surface area, particle and pore size distributions, and inter-particle neck size distribution, which may have varying extent of effect on the elastic properties simulated from the microstructures using FEM. Results showed that different threshold value range would result in different degree of sensitivity for a specific parameter. The estimated porosity and tortuosity were more sensitive than surface area to volume ratio. Pore and neck size were found to be less sensitive than particle size. Results also showed that the modulus was essentially sensitive to the porosity which was largely controlled by the threshold value.

Neuropsychological basic deficits in preschoolers at risk for ADHD: a meta-analysis.

PubMed

Pauli-Pott, Ursula; Becker, Katja

2011-06-01

Widely accepted neuropsychological theories on attention deficit hyperactivity disorder (ADHD) assume that the complex symptoms of the disease arise from developmentally preceding neuropsychological basic deficits. These deficits in executive functions and delay aversion are presumed to emerge in the preschool period. The corresponding normative developmental processes include phases of relative stability and rapid change. These non-linear developmental processes might have implications for concurrent and predictive associations between basic deficits and ADHD symptoms. To derive a description of the nature and strength of these associations, a meta-analysis was conducted. It is assumed that weighted mean effect sizes differ between basic deficits and depend on age. The meta-analysis included 25 articles (n=3005 children) in which associations between assessments of basic deficits (i.e. response inhibition, interference control, delay aversion, working memory, flexibility, and vigilance/arousal) in the preschool period and concurrent or subsequent ADHD symptoms or diagnosis of ADHD had been analyzed. For response inhibition and delay aversion, mean effect sizes were of medium to large magnitude while the mean effect size for working memory was small. Meta-regression analyses revealed that effect sizes of delay aversion tasks significantly decreased with increasing age while effect sizes of interference control tasks and Continuous Performance Tests (CPTs) significantly increased. Depending on the normative maturational course of each skill, time windows might exist that allow for a more or less valid assessment of a specific deficit. In future research these time windows might help to describe early developing forms of ADHD and to identify children at risk. Copyright © 2011 Elsevier Ltd. All rights reserved.

Celebrity Suicides and Their Differential Influence on Suicides in the General Population: A National Population-Based Study in Korea

PubMed Central

Myung, Woojae; Won, Hong-Hee; Fava, Maurizio; Mischoulon, David; Yeung, Albert; Lee, Dongsoo; Kim, Doh Kwan

2015-01-01

Objective Although evidence suggests that there is an increase in suicide rates in the general population following celebrity suicide, the rates are heterogeneous across celebrities and countries. It is unclear which is the more vulnerable population according to the effect sizes of celebrity suicides to general population. Methods All suicide victims in the general population verified by the Korea National Statistical Office and suicides of celebrity in South Korea were included for 7 years from 2005 to 2011. Effect sizes were estimated by comparing rates of suicide in the population one month before and after each celebrity suicide. The associations between suicide victims and celebrities were examined. Results Among 94,845 suicide victims, 17,209 completed suicide within one month after 13 celebrity suicides. Multivariate logistic regression analyses revealed that suicide victims who died after celebrity suicide were significantly likely to be of age 20-39, female, and to die by hanging. These qualities were more strongly associated among those who followed celebrity suicide with intermediate and high effect sizes than lower. Younger suicide victims were significantly associated with higher effect size, female gender, white collar employment, unmarried status, higher education, death by hanging, and night-time death. Characteristics of celebrities were significantly associated with those of general population in hanging method and gender. Conclusion Individuals who commit suicide after a celebrity suicide are likely to be younger, female, and prefer hanging as method of suicide, which are more strongly associated in higher effect sizes of celebrity suicide. PMID:25866521

Optimisation of sewage sludge anaerobic digestion through co-digestion with OFMSW: Effect of collection system and particle size.

PubMed

Silvestre, Gracia; Bonmatí, August; Fernández, Belén

2015-09-01

The effect of organic fraction of municipal solid waste (OFMSW) loading rate and particulate size on the sewage sludge (SS) mesophilic anaerobic co-digestion was assessed in continuous stirred tank reactor at hydraulic retention time of 20days. The SS-OFMSW mixture composed by 54% of the volatile solids fed (inlet-VS), at OLR of 3.1kgCODm(-3)d(-1) (1.9kgVSm(-3)d(-1)), showed the highest increment on the volumetric methane production and yield of +200% and +59% respectively, under stable conditions. The effect of particulate size was assessed with the same mixture and same operational conditions but reducing the OFMSW particulate size from 20mm to 8mm with the aim to improve the hydrolysis step, but the results showed any influence in the OFMSW particulate size range analysed. In addition, specific biomass activity was assessed at the end of each co-digestion period. Results showed that OFMSW promoted β-oxidation syntrophic acetogens and the acetoclastic methanogens activity; although the last increase of the OFMSW percentage (from 47% to 54% inlet-VS) affected negatively the specific substrate activity, but not inhibitory effect was observed. Therefore, the results obtained in the continuous experiment could be related with some inhibitory or toxic effect and not due to hydrolysis limitation. The specific biomass activity test was demonstrated to be an interesting tool to evaluate and control the co-digestion process, especially when conventional parameters did not explain the behaviour of the biological system. Copyright © 2015 Elsevier Ltd. All rights reserved.

Outlier Removal and the Relation with Reporting Errors and Quality of Psychological Research

PubMed Central

Bakker, Marjan; Wicherts, Jelte M.

2014-01-01

Background The removal of outliers to acquire a significant result is a questionable research practice that appears to be commonly used in psychology. In this study, we investigated whether the removal of outliers in psychology papers is related to weaker evidence (against the null hypothesis of no effect), a higher prevalence of reporting errors, and smaller sample sizes in these papers compared to papers in the same journals that did not report the exclusion of outliers from the analyses. Methods and Findings We retrieved a total of 2667 statistical results of null hypothesis significance tests from 153 articles in main psychology journals, and compared results from articles in which outliers were removed (N = 92) with results from articles that reported no exclusion of outliers (N = 61). We preregistered our hypotheses and methods and analyzed the data at the level of articles. Results show no significant difference between the two types of articles in median p value, sample sizes, or prevalence of all reporting errors, large reporting errors, and reporting errors that concerned the statistical significance. However, we did find a discrepancy between the reported degrees of freedom of t tests and the reported sample size in 41% of articles that did not report removal of any data values. This suggests common failure to report data exclusions (or missingness) in psychological articles. Conclusions We failed to find that the removal of outliers from the analysis in psychological articles was related to weaker evidence (against the null hypothesis of no effect), sample size, or the prevalence of errors. However, our control sample might be contaminated due to nondisclosure of excluded values in articles that did not report exclusion of outliers. Results therefore highlight the importance of more transparent reporting of statistical analyses. PMID:25072606

Lung size mismatch and primary graft dysfunction after bilateral lung transplantation *

PubMed Central

Eberlein, Michael; Reed, Robert M.; Bolukbas, Servet; Wille, Keith M.; Orens, Jonathan B.; Brower, Roy G.; Christie, Jason D.

2014-01-01

BACKGROUND Donor to recipient lung size matching at lung transplantation (LTx) can be estimated by the predicted total lung capacity (pTLC)ratio (donor pTLC/recipient pTLC). We aimed to determine whether the pTLC-ratio is associated with the risk of primary graft dysfunction (PGD) after bilateral LTx (BLT). METHODS We calculated the pTLC-ratio for 812 adult BLTs from the Lung Transplant Outcomes Group between 3/2002-12/2010. Patients were stratified by pTLC-ratio>1.0 (“oversized”) and pTLC-ratio≤1.0 (“undersized”). PGD was defined as any ISHLT grade 3 PGD within 72 hours of reperfusion (PGD 3). We analyzed the association between risk factors and PGD using multivariable conditional logistic regression. As transplant diagnoses can influence the size matching decisions and also modulate the risk for PGD, we performed pre-specified analyses by assessing the impact of lung size mismatch within diagnostic categories. RESULTS In univariate analyses oversizing was associated with a 39% lower odds of PGD3 (OR 0.61, 95% CI, p=0.003). In a multivariate model accounting for center effects and known PGD risks, oversizing remained independently associated with a decreased odds of PGD3 (OR 0.58, 95% CI 0.38-0.88, p=0.01). The risk adjusted point estimate was similar for the non-COPD diagnoses groups (OR 0.52, 95%CI 0.32-0.86, p=0.01); however there was no detected association within the COPD group (OR 0.72, 95% CI 0.29-1.78, p=0.5). CONCLUSION Oversized allografts are associated with a decreased risk of PGD3 after BLT; this effect appears most apparent in non-COPD patients. PMID:25447586

Grain-Scale Analyses of Curiosity Data at Marias Pass, Gale Crater, Mars: Methods Comparison and Depositional Interpretation

NASA Astrophysics Data System (ADS)

Sacks, L. E.; Edgar, L. A.; Edwards, C. S.; Anderson, R. B.

2016-12-01

Images acquired by the Mars Hand Lens Imager (MAHLI) and the ChemCam Remote Micro Imager (RMI) onboard the Mars Science Laboratory (MSL) Curiosity rover provide grain-scale data that are critical for interpreting sedimentary deposits. At the location informally known as Marias Pass, Curiosity used both cameras to image the nine rock targets used in this study. We used manual point-counts to measure grain size distributions from those images to compare the abilities of the two cameras. The manually derived results were compared to automated grain size data obtained using pyDGS (Digital Grain Size), an open-source python program. Grain size analyses were used to test the lacustrine and aeolian depositional hypotheses for the Murray and Stimson formations at Marias Pass. Results indicate that the MAHLI and RMI instruments, despite their different fields of view and properties, provide comparable grain size measurements. Additionally, pyDGS does not account for grains smaller than a few pixels and thus does not report representative grain size data and should not be used on images with a large fraction of unresolved grains. Finally, the data collected at Marias Pass are consistent with the existing interpretations of the Murray and Stimson formations. The fine-grained results of the Murray formation analyses support lacustrine deposition, while the mean grain size of the Stimson formation is fine to medium sized sand, consistent with aeolian deposition. However, directly above the contact with the Murray formation, larger rip-up clasts of the Murray formation are present in the Stimson formation. It is possible that water was involved at this stage of erosion and re-deposition, prior to aeolian deposition. Additionally, the grain-scale analyses conducted in this study show that the Dust Removal Tool on Curiosity should be used prior to capturing images for grain-scale analysis. Two images of the target informally named Ronan, taken before and after brushing, resulted in dramatically different grain size results, suggesting that the common, thin layer of dust obscured the true grain size distribution. These grain-scale analyses at Marias Pass have important implications for the collection and processing of image data, as well as the depositional environments recorded in Gale crater. Funded by NSF Grant AST-1461200

Characteristics of meta-analyses and their component studies in the Cochrane Database of Systematic Reviews: a cross-sectional, descriptive analysis

PubMed Central

2011-01-01

Background Cochrane systematic reviews collate and summarise studies of the effects of healthcare interventions. The characteristics of these reviews and the meta-analyses and individual studies they contain provide insights into the nature of healthcare research and important context for the development of relevant statistical and other methods. Methods We classified every meta-analysis with at least two studies in every review in the January 2008 issue of the Cochrane Database of Systematic Reviews (CDSR) according to the medical specialty, the types of interventions being compared and the type of outcome. We provide descriptive statistics for numbers of meta-analyses, numbers of component studies and sample sizes of component studies, broken down by these categories. Results We included 2321 reviews containing 22,453 meta-analyses, which themselves consist of data from 112,600 individual studies (which may appear in more than one meta-analysis). Meta-analyses in the areas of gynaecology, pregnancy and childbirth (21%), mental health (13%) and respiratory diseases (13%) are well represented in the CDSR. Most meta-analyses address drugs, either with a control or placebo group (37%) or in a comparison with another drug (25%). The median number of meta-analyses per review is six (inter-quartile range 3 to 12). The median number of studies included in the meta-analyses with at least two studies is three (inter-quartile range 2 to 6). Sample sizes of individual studies range from 2 to 1,242,071, with a median of 91 participants. Discussion It is clear that the numbers of studies eligible for meta-analyses are typically very small for all medical areas, outcomes and interventions covered by Cochrane reviews. This highlights the particular importance of suitable methods for the meta-analysis of small data sets. There was little variation in number of studies per meta-analysis across medical areas, across outcome data types or across types of interventions being compared. PMID:22114982

Improving diet and physical activity to reduce population prevalence of overweight and obesity: an overview of current evidence.

PubMed

Stephens, Samantha K; Cobiac, Linda J; Veerman, J Lennert

2014-05-01

The aim of this study is to provide an overview of interventions to reduce or prevent overweight or obesity and improve diet or physical activity. A review of meta-analyses and/or systematic reviews of these interventions in any setting or age group were conducted. Narrative systematic reviews were included for intervention categories with limited meta-analyses available. Summary measures including weighted mean difference, standardised mean difference, and I-squared, were examined. A total of 60 meta-analyses and 23 systematic reviews met the inclusion criteria. Dietary interventions and multi-component interventions targeting overweight and obesity appeared to have the greatest effects, particularly in comparison with workplace or technology or internet-based interventions. Pharmaceutical and surgical interventions produced favourable results for specific population sub-groups (i.e. morbidly obese). Population-wide strategies such as policy interventions have not been widely analysed. The effectiveness of the interventions to assist in maintaining behaviour or weight change remains unclear. Various individually targeted interventions were shown to reduce body weight, although effect sizes were typically modest, and the durability of effects has been questioned. New approaches to evaluating population-based interventions, such as taxes and regulation, are recommended. Future research modelling the long-term effects of interventions across the lifespan would also be beneficial. Copyright © 2014 Elsevier Inc. All rights reserved.

Threatening communication: a critical re-analysis and a revised meta-analytic test of fear appeal theory.

PubMed

Peters, Gjalt-Jorn Ygram; Ruiter, Robert A C; Kok, Gerjo

2013-05-01

Despite decades of research, consensus regarding the dynamics of fear appeals remains elusive. A meta-analysis was conducted that was designed to resolve this controversy. Publications that were included in previous meta-analyses were re-analysed, and a number of additional publications were located. The inclusion criteria were full factorial orthogonal manipulations of threat and efficacy, and measurement of behaviour as an outcome. Fixed and random effects models were used to compute mean effect size estimates. Meta-analysis of the six studies that satisfied the inclusion criteria clearly showed a significant interaction between threat and efficacy, such that threat only had an effect under high efficacy (d = 0.31), and efficacy only had an effect under high threat (d = 0.71). Inconsistency in results regarding the effectiveness of threatening communication can likely be attributed to flawed methodology. Proper tests of fear appeal theory yielded the theoretically hypothesised interaction effect. Threatening communication should exclusively be used when pilot studies indicate that an intervention successfully enhances efficacy.

Threatening communication: a critical re-analysis and a revised meta-analytic test of fear appeal theory

PubMed Central

Peters, Gjalt-Jorn Ygram; Ruiter, Robert A.C.; Kok, Gerjo

2013-01-01

Despite decades of research, consensus regarding the dynamics of fear appeals remains elusive. A meta-analysis was conducted that was designed to resolve this controversy. Publications that were included in previous meta-analyses were re-analysed, and a number of additional publications were located. The inclusion criteria were full factorial orthogonal manipulations of threat and efficacy, and measurement of behaviour as an outcome. Fixed and random effects models were used to compute mean effect size estimates. Meta-analysis of the six studies that satisfied the inclusion criteria clearly showed a significant interaction between threat and efficacy, such that threat only had an effect under high efficacy (d = 0.31), and efficacy only had an effect under high threat (d = 0.71). Inconsistency in results regarding the effectiveness of threatening communication can likely be attributed to flawed methodology. Proper tests of fear appeal theory yielded the theoretically hypothesised interaction effect. Threatening communication should exclusively be used when pilot studies indicate that an intervention successfully enhances efficacy. PMID:23772231

A meta-analysis of priming effects on impression formation supporting a general model of informational biases.

PubMed

DeCoster, Jamie; Claypool, Heather M

2004-01-01

Priming researchers have long investigated how providing information about traits in one context can influence the impressions people form of social targets in another. The literature has demonstrated that this can have 3 different effects: Sometimes primes become incorporated in the impression of the target (assimilation), sometimes they are used as standards of comparison (anchoring), and sometimes they cause people to consciously alter their judgments (correction). In this article, we present meta-analyses of these 3 effects. The mean effect size was significant in each case, such that assimilation resulted in impressions biased toward the primes, whereas anchoring and correction resulted in impressions biased away from the primes. Additionally, moderator analyses uncovered a number of variables that influence the strength of these effects, such as applicability, processing capacity, and the type of response measure. Based on these results, we propose a general model of how irrelevant information can bias judgments, detailing when and why assimilation and contrast effects result from default and corrective processes.

The Effect of Task Instructions on Students' Use of Repetition in Argumentative Discourse

ERIC Educational Resources Information Center

Gilabert, Sandra; Garcia-Mila, Merce; Felton, Mark K.

2013-01-01

The reasoning belief of "argumentum ad nauseam" assumes that when someone repeats something often enough, he or she becomes more convincing. The present paper analyses the use of this strategy by seventh-grade students in an argumentation task. Sixty-five students (mean age: 12.2, SD?=?0.4) from a public school in a mid-sized urban…

The Relationship between Visual Analysis and Five Statistical Analyses in a Simple AB Single-Case Research Design

ERIC Educational Resources Information Center

Brossart, Daniel F.; Parker, Richard I.; Olson, Elizabeth A.; Mahadevan, Lakshmi

2006-01-01

This study explored some practical issues for single-case researchers who rely on visual analysis of graphed data, but who also may consider supplemental use of promising statistical analysis techniques. The study sought to answer three major questions: (a) What is a typical range of effect sizes from these analytic techniques for data from…

"Are cognitive interventions effective in Alzheimer's disease? A controlled meta- analysis of the effects of bias": Correction to Oltra-Cucarella et al. (2016).

PubMed

2016-07-01

Reports an error in "Are Cognitive Interventions Effective in Alzheimer's Disease? A Controlled Meta-Analysis of the Effects of Bias" by Javier Oltra-Cucarella, Rubén Pérez-Elvira, Raul Espert and Anita Sohn McCormick (Neuropsychology, Advanced Online Publication, Apr 7, 2016, np). In the article the first sentence of the third paragraph of the Source of bias subsection in the Statistical Analysis subsection of the Correlational Meta-Analysis section should read "For the control condition bias, three comparison groups were differentiated: (a) a structured cognitive intervention, (b) a placebo control condition, and (c) a pharma control condition without cognitive intervention or no treatment at all." (The following abstract of the original article appeared in record 2016-16656-001.) There is limited evidence about the efficacy of cognitive interventions for Alzheimer's disease (AD). However, aside from the methodological quality of the studies analyzed, the methodology used in previous meta-analyses is itself a risk of bias as different types of effect sizes (ESs) were calculated and combined. This study aimed at examining the results of nonpharmacological interventions for AD with an adequate control of statistical methods and to demonstrate a different approach to meta-analysis. ESs were calculated with the independent groups pre/post design. Average ESs for separate outcomes were calculated and moderator analyses were performed so as to offer an overview of the effects of bias. Eighty-seven outcomes from 19 studies (n = 812) were meta-analyzed. ESs were small on average for cognitive and functional outcomes after intervention. Moderator analyses showed no effect of control of bias, although ESs were different from zero only in some circumstances (e.g., memory outcomes in randomized studies). Cognitive interventions showed no more efficacy than placebo interventions, and functional ESs were consistently low across conditions. cognitive interventions delivered may not be effective in AD probably due to the fact that the assumptions behind the cognitive interventions might be inadequate. Future directions include a change in the type of intervention as well as the use of outcomes other than standardized tests. Additional studies with larger sample sizes and different designs are needed to increase the power of both primary studies and meta-analyses. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Accounting for standard errors of vision-specific latent trait in regression models.

PubMed

Wong, Wan Ling; Li, Xiang; Li, Jialiang; Wong, Tien Yin; Cheng, Ching-Yu; Lamoureux, Ecosse L

2014-07-11

To demonstrate the effectiveness of Hierarchical Bayesian (HB) approach in a modeling framework for association effects that accounts for SEs of vision-specific latent traits assessed using Rasch analysis. A systematic literature review was conducted in four major ophthalmic journals to evaluate Rasch analysis performed on vision-specific instruments. The HB approach was used to synthesize the Rasch model and multiple linear regression model for the assessment of the association effects related to vision-specific latent traits. The effectiveness of this novel HB one-stage "joint-analysis" approach allows all model parameters to be estimated simultaneously and was compared with the frequently used two-stage "separate-analysis" approach in our simulation study (Rasch analysis followed by traditional statistical analyses without adjustment for SE of latent trait). Sixty-six reviewed articles performed evaluation and validation of vision-specific instruments using Rasch analysis, and 86.4% (n = 57) performed further statistical analyses on the Rasch-scaled data using traditional statistical methods; none took into consideration SEs of the estimated Rasch-scaled scores. The two models on real data differed for effect size estimations and the identification of "independent risk factors." Simulation results showed that our proposed HB one-stage "joint-analysis" approach produces greater accuracy (average of 5-fold decrease in bias) with comparable power and precision in estimation of associations when compared with the frequently used two-stage "separate-analysis" procedure despite accounting for greater uncertainty due to the latent trait. Patient-reported data, using Rasch analysis techniques, do not take into account the SE of latent trait in association analyses. The HB one-stage "joint-analysis" is a better approach, producing accurate effect size estimations and information about the independent association of exposure variables with vision-specific latent traits. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

Design of trials for interrupting the transmission of endemic pathogens.

PubMed

Silkey, Mariabeth; Homan, Tobias; Maire, Nicolas; Hiscox, Alexandra; Mukabana, Richard; Takken, Willem; Smith, Thomas A

2016-06-06

Many interventions against infectious diseases have geographically diffuse effects. This leads to contamination between arms in cluster-randomized trials (CRTs). Pathogen elimination is the goal of many intervention programs against infectious agents, but contamination means that standard CRT designs and analyses do not provide inferences about the potential of interventions to interrupt pathogen transmission at maximum scale-up. A generic model of disease transmission was used to simulate infections in stepped wedge cluster-randomized trials (SWCRTs) of a transmission-reducing intervention, where the intervention has spatially diffuse effects. Simulations of such trials were then used to examine the potential of such designs for providing generalizable causal inferences about the impact of such interventions, including measurements of the contamination effects. The simulations were applied to the geography of Rusinga Island, Lake Victoria, Kenya, the site of the SolarMal trial on the use of odor-baited mosquito traps to eliminate Plasmodium falciparum malaria. These were used to compare variants in the proposed SWCRT designs for the SolarMal trial. Measures of contamination effects were found that could be assessed in the simulated trials. Inspired by analyses of trials of insecticide-treated nets against malaria when applied to the geography of the SolarMal trial, these measures were found to be robust to different variants of SWCRT design. Analyses of the likely extent of contamination effects supported the choice of cluster size for the trial. The SWCRT is an appropriate design for trials that assess the feasibility of local elimination of a pathogen. The effects of incomplete coverage can be estimated by analyzing the extent of contamination between arms in such trials, and the estimates also support inferences about causality. The SolarMal example illustrates how generic transmission models incorporating spatial smoothing can be used to simulate such trials for a power calculation and optimization of cluster size and randomization strategies. The approach is applicable to a range of infectious diseases transmitted via environmental reservoirs or via arthropod vectors.

Changes in variation at the MHC class II DQA locus during the final demise of the woolly mammoth

NASA Astrophysics Data System (ADS)

Pečnerová, Patrícia; Díez-Del-Molino, David; Vartanyan, Sergey; Dalén, Love

2016-05-01

According to the nearly-neutral theory of evolution, the relative strengths of selection and drift shift in favour of drift at small population sizes. Numerous studies have analysed the effect of bottlenecks and small population sizes on genetic diversity in the MHC, which plays a central role in pathogen recognition and immune defense and is thus considered a model example for the study of adaptive evolution. However, to understand changes in genetic diversity at loci under selection, it is necessary to compare the genetic diversity of a population before and after the bottleneck. In this study, we analyse three fragments of the MHC DQA gene in woolly mammoth samples radiocarbon dated to before and after a well-documented bottleneck that took place about ten thousand years ago. Our results indicate a decrease in observed heterozygosity and number of alleles, suggesting that genetic drift had an impact on the variation on MHC. Based on coalescent simulations, we found no evidence of balancing selection maintaining MHC diversity during the Holocene. However, strong trans-species polymorphism among mammoths and elephants points to historical effects of balancing selection on the woolly mammoth lineage.

A vertical-energy-thresholding procedure for data reduction with multiple complex curves.

PubMed

Jung, Uk; Jeong, Myong K; Lu, Jye-Chyi

2006-10-01

Due to the development of sensing and computer technology, measurements of many process variables are available in current manufacturing processes. It is very challenging, however, to process a large amount of information in a limited time in order to make decisions about the health of the processes and products. This paper develops a "preprocessing" procedure for multiple sets of complicated functional data in order to reduce the data size for supporting timely decision analyses. The data type studied has been used for fault detection, root-cause analysis, and quality improvement in such engineering applications as automobile and semiconductor manufacturing and nanomachining processes. The proposed vertical-energy-thresholding (VET) procedure balances the reconstruction error against data-reduction efficiency so that it is effective in capturing key patterns in the multiple data signals. The selected wavelet coefficients are treated as the "reduced-size" data in subsequent analyses for decision making. This enhances the ability of the existing statistical and machine-learning procedures to handle high-dimensional functional data. A few real-life examples demonstrate the effectiveness of our proposed procedure compared to several ad hoc techniques extended from single-curve-based data modeling and denoising procedures.

Socioeconomic status and antisocial behaviour among children and adolescents: a systematic review and meta-analysis.

PubMed

Piotrowska, Patrycja J; Stride, Christopher B; Croft, Simone E; Rowe, Richard

2015-02-01

Previous research on the association between socioeconomic status (SES) and child and adolescent antisocial behaviour has produced mixed findings showing variation in the strength of association. This systematic review and meta-analysis aimed to summarise evidence on the relationship between socioeconomic status and broadly conceptualised antisocial behaviour, investigating variation across a range of antisocial subtypes and other potential moderators, including age, sex and informant. We identified 133 studies containing data suitable for effect size calculation, and 139 independent effect sizes were analysed (total N=339868). The global meta-analysis showed that lower family socioeconomic status was associated with higher levels of antisocial behaviour. Moderation analyses revealed this relationship was stronger where callous-unemotional traits were the outcome, and where antisocial behaviour was reported by parents or teachers rather than self-reported. The relationship between family SES and antisocial behaviour, however, was independent of higher-level constructs such as national income inequality. These results indicate that SES can be considered a robust correlate of broadly conceptualised antisocial behaviour but the strength of this relationship may depend on the antisocial subtype under investigation and the design of the study. Copyright © 2014. Published by Elsevier Ltd.