Unweighted regression models perform better than weighted regression techniques for respondent-driven sampling data: results from a simulation study

Background: It is unclear whether weighted or unweighted regression is preferred in the analysis of data derived from respondent driven sampling. Our objective was to evaluate the validity of various regression models, with and without weights and with various controls for clustering in the estimation of the risk of group membership from data collected using respondent-driven sampling (RDS). Methods: Twelve networked populations, with varying levels of homophily and prevalence, based on a known distribution of a continuous predictor were simulated using 1000 RDS samples from each population. Weighted and unweighted binomial and Poisson general linear models, with and without various clustering controls and standard error adjustments were modelled for each sample and evaluated with respect to validity, bias and coverage rate. Population prevalence was also estimated. Results: In the regression analysis, the unweighted log-link (Poisson) models maintained the nominal type-I error rate across all populations. Bias was substantial and type-I error rates unacceptably high for weighted binomial regression. Coverage rates for the estimation of prevalence were highest using RDS-weighted logistic regression, except at low prevalence (10%) where unweighted models are recommended. Conclusions: Caution is warranted when undertaking regression analysis of RDS data. Even when reported degree is accurate, low reported degree can unduly influence regression estimates. Unweighted Poisson regression is therefore recommended.York University Librarie

Architecture as a Medium of Exchange

The notion of universal order is ancient, but when the scientific method came into being four hundred years ago it led to theories that have proved revelatory in their uncovering of the hidden order in the universe - an order governed by a system of natural laws not able to be detected by the senses alone

Desert Time

Chase was sitting on Dante’s point on top of the Amargosa Mountain Range, which runs north and south defining the eastern edge of Death Valley, California. The “Big D” he calls it

Sixth Street Residence

Program: The reconstruction of an existing duplex to the specifications required of the new owner. Site: 60\u27 x 60\u27 parcel @ the corner of a typical residential street and an alley in Santa Monica, Calif

On-ice measures of external load in relation to match outcome in elite female ice hockey

The aim of this study is to investigate the differences between select on-ice measures using inertial movement sensors based on match outcome, and to determine changes in player movements across three periods of play. Data were collected during one season of competition in elite female ice hockey players (N = 20). Two-factor mixed effects ANOVAs for each skating position were performed to investigate the differences in match outcome, as well as differences in external load measures during the course of a match. For match outcome, there was a small difference for forwards in explosive ratio (p = 0.02, ES = 0.26) and percentage high force strides (p = 0.04, ES = 0.50). When viewed across three periods of a match, moderate differences were found in skating load (p = 0.01, ES = 0.75), explosive efforts (p = 0.04, ES = 0.63), and explosive ratio (p = 0.002, ES = 0.87) for forwards, and in PlayerLoad (p = 0.01, ES = 0.70), explosive efforts (p = 0.04, ES = 0.63), and explosive ratio (p = 0.01, ES = 0.70) for defense. When examining the relevance to match outcome, external load measures associated with intensity appear to be an important factor among forwards. These results may be helpful for coaches and sport scientists when making decisions pertaining to training and competition strategies.York University Librarie

The Influence of Urinary Concentrations of Organophosphate Metabolites on the Relationship between BMI and Cardiometabolic Health Risk

The objective was to determine whether detectable levels of OP metabolites influence the relationship between BMI and cardiometabolic health. This cross-sectional study was conducted using 2227 adults from the 1999–2008 NHANES datasets. Urinary concentrations of six dialkyl phosphate metabolites were dichotomized to above and below the detection limit. Weighted multiple regression analysis was performed adjusting for confounding variables. Independent of BMI, individuals with detectable metabolites had higher diastolic blood pressure (for dimethylphosphate, diethylphosphate, and diethyldithiophosphate; P<0.05), lower HDL (for diethyldithiophosphate; P=0.02), and higher triglyceride (for dimethyldithiophosphate; P=0.05) than those below detection. Contrarily, those with detectable dimethylthiophosphate had better LDL, HDL, and total cholesterol, independent of BMI. Individuals at a higher BMI range who had detectable diethylphosphate (interaction: P=0.03) and diethylthiophosphate (interaction: P=0.02) exhibited lower HDL, while little difference existed between OP metabolite detection statuses at lower BMIs. Similarly, individuals with high BMIs and detectable diethylphosphate had higher triglyceride than those without detectable levels, while minimal differences between diethylphosphate detection statuses were observed at lower BMIs (interaction: P=0.02). Thus, cardiometabolic health outcome differs depending on the specific OP metabolite being examined, with higher BMIs amplifying health risk

Mindfulness as an Alternative for Supporting University Student Mental Health: Cognitive-Emotional and Depressive Self-Criticism Measures

Increases in university-based mental health problems require alternative mental health programs, applicable to students with elevated psychological risks due to personality traits. This study examined the cognitive-emotional outcomes of a university mindfulness meditation (MM) program and their relationship with Self-Criticism (SC), a personality factor linked to depressive vulnerability. University students (n = 71) were assessed at baseline with the Depressive Experiences Questionnaire (DEQ), a measure of depressive personality traits, and two outcome measures: Profile of Mood States (POMS) and Anxiety Sensitivity Index (ASI). Students attending the MM program were reassessed for outcomes at 3 follow up assessments over 2 semesters. Repeated measures analyses of variance revealed improved within-subjects effects with large or very large effect sizes for the subsample that completed the MM program (n = 18) on the POMS Tension-Anxiety, POMS Depression, POMS Fatigue, and Anxiety Sensitivity Index. Multiple linear regression using self-criticism as a predictor of change in depressed mood revealed that higher self-criticism predicted greater reductions in POMS Depression. This study provides evidence for MM-related cognitive-emotional benefits, suggesting that students with elevated self-critical traits may derive exceptional benefits evident in greater reductions of depressed mood

Mindfulness as an Alternative for Supporting University Student Mental Health: Cognitive-Emotional and Depressive Self-Criticism Measures

Increases in university-based mental health problems require alternative mental health programs, applicable to students with elevated psychological risks due to personality traits. This study examined the cognitive-emotional outcomes of a university mindfulness meditation (MM) program and their relationship with Self-Criticism (SC), a personality factor linked to depressive vulnerability. University students (n = 71) were assessed at baseline with the Depressive Experiences Questionnaire (DEQ), a measure of depressive personality traits, and two outcome measures: Profile of Mood States (POMS) and Anxiety Sensitivity Index (ASI). Students attending the MM program were reassessed for outcomes at 3 follow up assessments over 2 semesters. Repeated measures analyses of variance revealed improved within-subjects effects with large or very large effect sizes for the subsample that completed the MM program (n = 18) on the POMS Tension-Anxiety, POMS Depression, POMS Fatigue, and Anxiety Sensitivity Index. Multiple linear regression using self-criticism as a predictor of change in depressed mood revealed that higher self-criticism predicted greater reductions in POMS Depression. This study provides evidence for MM-related cognitive-emotional benefits, suggesting that students with elevated self-critical traits may derive exceptional benefits evident in greater reductions of depressed mood

\u3cem\u3eBorrelia burgdorferi\u3c/em\u3e EbfC Defines a Newly-Identified, Widespread Family of Bacterial DNA-Binding Proteins

The Lyme disease spirochete, Borrelia burgdorferi, encodes a novel type of DNA-binding protein named EbfC. Orthologs of EbfC are encoded by a wide range of bacterial species, so characterization of the borrelial protein has implications that span the eubacterial kingdom. The present work defines the DNA sequence required for high-affinity binding by EbfC to be the 4 bp broken palindrome GTnAC, where ‘n’ can be any nucleotide. Two high-affinity EbfC-binding sites are located immediately 5′ of B. burgdorferi erp transcriptional promoters, and binding of EbfC was found to alter the conformation of erp promoter DNA. Consensus EbfC-binding sites are abundantly distributed throughout the B. burgdorferi genome, occurring approximately once every 1 kb. These and other features of EbfC suggest that this small protein and its orthologs may represent a distinctive type of bacterial nucleoid-associated protein. EbfC was shown to bind DNA as a homodimer, and site-directed mutagenesis studies indicated that EbfC and its orthologs appear to bind DNA via a novel α-helical ‘tweezer’-like structure