Estimation of Zero-Inflated Population Mean: A Bootstrapping Approach

A mixture model was adopted from the maximum pseudo-likelihood approach under complex sampling designs to estimate the mean of zero-inflated population. To overcome the complexity and assumptions of asymptotic distribution, the maximum pseudo-likelihood function was used, but a bootstrapping procedure was proposed as an alternative. Bootstrap confidence intervals consistently capture the true means of zero-inflated populations of the simulation studies

Regularizing threshold priors with sparse response patterns in Bayesian factor analysis with categorical indicators

Using instruments comprising ordered responses to items are ubiquitous for studying many constructs of interest. However, using such an item response format may lead to items with response categories infrequently endorsed or unendorsed completely. In maximum likelihood estimation, this results in non-existing estimates for thresholds. This work focuses on a Bayesian estimation approach to counter this issue. The issue changes from the existence of an estimate to how to effectively construct threshold priors. The proposed prior specification reconceptualizes the threshold prior as prior on the probability of each response category. A metric that is easier to manipulate while maintaining the necessary ordering constraints on the thresholds. The resulting induced-prior is more communicable, and we demonstrate comparable statistical efficiency that existing threshold priors. Evidence is provided using a simulated data set, a Monte Carlo simulation study, and an example multi-group item-factor model analysis. All analyses demonstrate how at least a relatively informative threshold prior is necessary to avoid inefficient posterior sampling and increase confidence in the coverage rates of posterior credible intervals

Developmental Changes in Graduate Student Supervisory Needs and Expectations: A Longitudinal Investigation

Supervision of graduate students in the field of speech-language pathology during their pre-service training is critical to their professional development. The present study followed a cohort of graduate students (N=31) over the course of their clinical training to track changes in their self-reported needs and expectations regarding clinical supervision practices. Over the course of one year, graduate students’ self-reported supervisory needs and expectations decreased significantly with the exception of those variables associated with supervisor-controlled behaviors such as serving as a teacher rather than a colleague. Implications for incorporating supervisee perceptions into effective supervision practices and directions for future research are discussed

Mental Health Best Practices in NCAA: The Bidirectional Relationship between Mental Toughness and Self-Compassion

Based on National Collegiate Athletic Association (NCAA) reports, student-athletes’ well-being is compromised by sub-clinical issues of mental health (MH) disorders, such as depression and anxiety. Preliminary data have shown a positive relationship between mental toughness (MT) and MH, self-compassion (SC) and MH, and SC and MT. To date, possible indirect causal relationships between these three constructs have not been investigated. PURPOSE: To confirm the three aforementioned relationships in NCAA athletes and explore the mediation role of MT and SC on the SC-MH and MT-MH relationships, respectively. Hypotheses: (1) MT will correlate positively with MH, (2) SC will correlate positively with MH, (3) MT will correlate positively with SC, (4) MT will mediate the SC-MH relationship, and (5) SC will mediate the MT-MH relationship. METHODS: The Mental Toughness Index, the Self-Compassion Scale, and the Mental Health Continuum-Short Form were uploaded on Qualtrics. NCAA athletes were invited to participate via email. The sample (n=466) was predominantly Division III, White, female, freshmen, soccer players, and in-season (Mage=19.8, SD=1.8). The analysis consisted of two parts. In the first, bivariate correlations were computed among MT, SC, and MH. In the second, a structural equation model was constructed to test the bidirectional relationship between MT and SC, where MT and SC also had direct effects on MH. All analyses were completed in R. RESULTS: The findings showed a positive relationship between MT and MH (r=0.371, pr=0.461, pr=0.533, pCONCLUSION: Our positive correlation results are in accordance with Gucciardi, Hanton, and Fleming (2017), Neff, Rude, and Kirkpatrick (2007), Wilson, Bennett, Mosewich, Faulkner, and Crocker (2018), and Ales, Kurzum, Deal, and Stamatis (2018). The full bidirectional model analysis revealed that MT is associated with increases in SC and increases in both MT and SC are associated with increases in MH. Therefore and concerning updating mental health best practices, both MT and SC psychological skill training can potentially increase MH levels. However, to most appropriately increase athletes’ MH, stakeholders should prioritize MT, over and above SC, but not to its detriment. Possible limitations include self-assessment and athletes representing three institutions only. Similar, larger-scale research projects are needed in the future

Body image and antiretroviral therapy adherence among people living with HIV: a protocol for a systematic review and meta-analysis.

HEARD, 2021.Introduction Adherence to antiretroviral therapy (ART) remains a key challenge to achieving the fast-track goal of ending the HIV epidemic by 2030. To provide a more comprehensive indication of whether interventions designed to promote ART adherence might benefit from targeting body image perceptions, we aim to conduct a systematic review to synthesise existing evidence on the association between body image and ART adherence. Methods and analysis A systematic review of peer-reviewed observational studies and randomised controlled trials that have investigated the association between body image and adherence to ART will be performed. JSTOR, PsycARTICLES, PsycINFO, PubMed, ScienceDirect and Web of Science databases will be searched from 1 January 2000 to 31 March 2021. Eligible records will consider body image as either an independent variable or a mediator, whereas ART adherence will be assessed as an outcome variable. Study selection will follow the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and study quality will be assessed using relevant tools developed by the National Institute of Health. If sufficient data are available, a meta-analysis will be conducted. Effect size estimates will be aggregated using a random effects meta-analysis approach. Publication bias and its impact will be evaluated through the use of a funnel plot and the trim-and-fill method. The Grading of Recommendations Assessment, Development and Evaluation approach will be used to report on the overall quality of evidence

Interaction between the microbiome and TP53 in human lung cancer.

BACKGROUND: Lung cancer is the leading cancer diagnosis worldwide and the number one cause of cancer deaths. Exposure to cigarette smoke, the primary risk factor in lung cancer, reduces epithelial barrier integrity and increases susceptibility to infections. Herein, we hypothesize that somatic mutations together with cigarette smoke generate a dysbiotic microbiota that is associated with lung carcinogenesis. Using lung tissue from 33 controls and 143 cancer cases, we conduct 16S ribosomal RNA (rRNA) bacterial gene sequencing, with RNA-sequencing data from lung cancer cases in The Cancer Genome Atlas serving as the validation cohort. RESULTS: Overall, we demonstrate a lower alpha diversity in normal lung as compared to non-tumor adjacent or tumor tissue. In squamous cell carcinoma specifically, a separate group of taxa are identified, in which Acidovorax is enriched in smokers. Acidovorax temporans is identified within tumor sections by fluorescent in situ hybridization and confirmed by two separate 16S rRNA strategies. Further, these taxa, including Acidovorax, exhibit higher abundance among the subset of squamous cell carcinoma cases with TP53 mutations, an association not seen in adenocarcinomas. CONCLUSIONS: The results of this comprehensive study show both microbiome-gene and microbiome-exposure interactions in squamous cell carcinoma lung cancer tissue. Specifically, tumors harboring TP53 mutations, which can impair epithelial function, have a unique bacterial consortium that is higher in relative abundance in smoking-associated tumors of this type. Given the significant need for clinical diagnostic tools in lung cancer, this study may provide novel biomarkers for early detection

Assessing local fit by approximating probabilities

Validity evidence for factor structures underlying a set of items can come from how well a proposed model reconstructs, or fits, the observed relationships. Global model fit is limited in that some components of the proposed model fit better than other components. This limitation has lead to the recommendation of examining fit locally within model components. We describe a new probabilistic approach to assessing local fit using a Bayesian approximation and illustrate use with a simulated dataset. We show how the posterior approximation closely approximated the sampling distribution of the true parameter. We discuss potential limitations and possible generalizations

Assessing Local Fit in Confirmatory Factor Models by Approximating Probabilities

Validity evidence for factor structures underlying a set of items can come from how well a proposed model reconstructs, or fits, the observed relationships. Global model fit is limited in that some components of the proposed model fit better than other components. This limitation has led to the recommendation of examining fit locally within model components. A new probabilistic approach to assessing local fit using a Bayesian approximation will be described and illustrated with the use of a simulated dataset. I will show how the posterior approximation closely approximated the sampling distribution of the true parameter. Potential limitations and possible generalizations will be discussed

Cross wave measurement invariance

https://noah-padgett.github.io/reliability-and-longitudinal-invariance/longitudinal-invariance.htm