Search

Marginal maximum likelihood, a common estimation method for item response theory models, is not inherently a Bayesian procedure. However, due to estimation difficulties, Bayesian priors are often applied to the likelihood when estimating 3PL models, especially with small samples. Little focus has been placed on choosing the priors for marginal maximum estimation. In this study, using sample sizes of 1,000 or smaller, not using priors often led to extreme, implausible parameter estimates. Applying prior distributions to the c -parameters alleviated the estimation problems with samples of 500 or more; for the samples of 100, priors on both the a -parameters and c -parameters were needed. Estimates were biased when the mode of the prior did not match the true parameter value, but the degree of the bias did not depend on the strength of the prior unless it was extremely informative. The root mean squared error (RMSE) of the a -parameters and b -parameters did not depend greatly on either the mode or the strength of the prior unless it was extremely informative. The RMSE of the c -parameters, like the bias, depended on the mode of the prior for c ., Competing Interests: The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2023.)

Introduction: The emergence of the novel severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) rapidly evolved into a worldwide pandemic of Coronavirus Disease 2019 (COVID-19). The pandemic had a major operational impact upon the US military, requiring interventions to mitigate transmission risk resulting in DoD-wide disruption of daily operations, restriction of movement, and delays in training. Development of a rapid mobile COVID-19 testing strategy was pursued as a means to allow service members to complete critical missions in select settings. In this report, we describe the first of its kind mobile medical laboratory (MML) that allowed for testing of approximately 4,000 soldiers of the 1/34th Armored Brigade Combat Team (1/34th ABCT), 34th Infantry Division, prior to deployment for validation exercises to the National Training Center, Fort Irwin, CA. We describe the utilizing of the MML, COVID-19 testing workflow, clinical symptom data/cycle threshold (Ct) data from positive patients, and outcomes from this testing mission.

Background: Tetraploid cotton plants serve as prime natural fiber source for the textile industry. Although various omics studies have revealed molecular basis for fiber development, a better understanding of transcriptional regulation mechanism regulating lint fiber initiation is necessary to meet global natural fiber demand., Results: Here, we aimed to perform transcriptome sequencing to identify DEGs (differentially expressed genes) in ovules of the cotton variety Xu142 and its fibreless mutant Xu142fl during early lint fiber initiation period. Totally, 5516 DEGs including 1840 upregulated and 3676 downregulated were identified. GO enrichment analysis revealed that the downregulated DEGs were mainly associated with biological processes such as transcription related biosynthesis and metabolism, organic cyclic compound biosynthesis and metabolism, photosynthesis, and plant cell wall organization, with molecular functions involving transcription related binding, organic cyclic compound binding, and dioxygenase activity, while the upregulated DEGs were associated with DNA replication and phospholipid biosynthetic related processes. Among the 490 DEGs annotated as transcription factor genes, 86.5% were downregulated in the mutant including the Malvaceae-specific MMLs, expression patterns of which were confirmed during the central period of lint fiber initiation. Investigation of the 16 genes enriched in the cell wall organization revealed that 15 were EXPA coding genes., Conclusions: Overall, our data indicate that lint fiber initiation is a complicated process involving cooperation of multiple transcription factor families, which might ultimately lead to the reorganization of the cell wall and terminated cell division of the differentiating fiber initials., (© 2021. The Author(s).)

Lightweight composite materials have recently been recognized as appropriate materials have been adopted in many industrial applications because of their versatility. The present research recognizes the inclusion of ceramics such as Gr and B 4 C in manufacturing AMMCs through stir casting. Prepared composites were tested for hardness and wear behaviour. The tests' findings revealed that the reinforced matrix was harder (60%) than the un-reinforced alloy because of the increased ceramic phase. The rising content of B 4 C and Gr particles led to continuous improvements in wear resistance. The microstructure and worn surface were observed through SEM (Scanning electron microscope) and revealed the formation of mechanically mixed layers of both B 4 C and Gr, which served as the effective insulation surface and protected the test sample surface from the steel disc. With the rise in the content of B 4 C and Gr, the weight loss declined, and significant wear resistance was achieved at 15 wt.% B 4 C and 10 wt.% Gr. A response surface analysis for the weight loss was carried out to obtain the optimal objective function. Artificial neural network methodology was adopted to identify the significance of the experimental results and the importance of the wear parameters. The error between the experimental and ANN results was found to be within 1%.

In the United States, policies regarding the medical and nonmedical use of cannabis are changing rapidly. In 2021, a total of 34 US states have legalized cannabis for adult medical use, and 15 of these states have legalized adult non-medical use. These changing policies have raised questions about increasing prevalences of cannabis use, changing perceptions regarding frequent use, and potentially related outcomes such as comorbid psychiatric illness or driving under the influence of cannabis. Research regarding the correlates of any and frequent cannabis use is also developing quickly. This article reviews recent empirical studies concerning (1) adult trends in cannabis use, (2) state cannabis laws and related outcomes, and (3) emerging evidence regarding how the global coronavirus 19 pandemic may impact cannabis use patterns. We summarize recent findings and conclude with suggestions to address unanticipated effects of rapidly changing cannabis laws and policies., Competing Interests: Conflict of interest statement Nothing declared., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Heterogeneity of tinnitus imposes a challenge for its treatment. Identifying tinnitus subtypes might help to establish individualized diagnosis and therapies. The minimum masking level (MML) is a clinical tool defined as the minimum intensity of a masking sound required to cover tinnitus. Understanding the differences among masking patterns in patients could facilitate the task of subtyping tinnitus. Here, we studied the variability of hearing thresholds and MMLs among patients with tinnitus to identify tinnitus subgroups. A population of 366 consecutive patients from a specialized tinnitus clinic were included in the analysis. Hearing thresholds and MMLs were determined for octave frequencies from 0.25 to 8kHz, as well as for 3 and 6kHz. Subjects were divided into two groups according to whether their tinnitus was maskable (M, 329 subjects) or non-maskable (NM, 37 subjects). Hearing thresholds and tinnitus loudness did not differ significantly between both groups. The dimensionality of the data was reduced by means of principal component analysis (PCA), and the largest resulting components were used for clustering the data. The cluster analysis resulted in five clusters with differences in tinnitus pitch, lateralization, hearing thresholds and MML, as well as on age and gender. Clusters differed in contours of hearing thresholds and MML, describing patterns of low or high thresholds in combination with low or high MML. The clustering solution presented a low silhouette value (0.45), implying that the clustering is weak and could be artificial. The analysis pointed out the diversity across tinnitus patients. Our results suggest that there might be a continuum of patients' characteristics rather than discrete subgroups., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Medical Markup Language (MML) is a standard format for exchange of healthcare data among healthcare providers. Following the last major update (version 3), we developed new modules and discussed the requirements for the next major updates. Subsequently, in 2016 we released MML version 4 and used it to obtain clinical data from healthcare providers for a nationwide electronic health records (EHR) system. In this article we provide an overview of this major update of MML version 4 and discuss its interoperability for clinical data.

We recently developed an unsupervised Bayesian inference methodology to automatically infer a dictionary of protein supersecondary structures (Subramanian et al., IEEE data compression conference proceedings (DCC), 340-349, 2017). Specifically, this methodology uses the information-theoretic framework of minimum message length (MML) criterion for hypothesis selection (Wallace, Statistical and inductive inference by minimum message length, Springer Science & Business Media, New York, 2005). The best dictionary of supersecondary structures is the one that yields the most (lossless) compression on the source collection of folding patterns represented as tableaux (matrix representations that capture the essence of protein folding patterns (Lesk, J Mol Graph. 13:159-164, 1995). This book chapter outlines our MML methodology for inferring the supersecondary structure dictionary. The inferred dictionary is available at http://lcb.infotech.monash.edu.au/proteinConcepts/scop100/dictionary.html .

Although considerable developments have been added to the cognitive diagnosis modeling literature recently, most have been conducted for dichotomous responses only. This research proposes a general cognitive diagnosis model for polytomous responses-the general polytomous diagnosis model (GPDM), which combines the G-DINA modeling process for dichotomous responses with the item-splitting process for polytomous responses. The polytomous items are specified similar to dichotomous items in the Q-matrix, and the MML estimation is implemented using an EM algorithm. Under the general framework, different saturated forms, and some reduced forms, can be transformed linearly. Model assessment and adjustment under the dichotomous context can be extended to polytomous responses. This simulation study demonstrates the effectiveness of the model when comparing the two response types. The real-data example further illustrates how the proposed model can make a difference in practice.

This study compared several parameter estimation methods for multi-unidimensional graded response models using their corresponding statistical software programs and packages. Specifically, we compared two marginal maximum likelihood (MML) approaches (Bock-Aitkin expectation-maximum algorithm, adaptive quadrature approach), four fully Bayesian algorithms (Gibbs sampling, Metropolis-Hastings, Hastings-within-Gibbs, blocked Metropolis), and the Metropolis-Hastings Robbins-Monro (MHRM) algorithm via the use of IRTPRO, BMIRT, and MATLAB. Simulation results suggested that, when the intertrait correlation was low, these estimation methods provided similar results. However, if the dimensions were moderately or highly correlated, Hastings-within-Gibbs had an overall better parameter recovery of item discrimination and intertrait correlation parameters. The performances of these estimation methods with different sample sizes and test lengths are also discussed.

Marginal maximum likelihood estimation based on the expectation-maximization algorithm (MML/EM) is developed for the one-parameter logistic model with ability-based guessing (1PL-AG) item response theory (IRT) model. The use of the MML/EM estimator is cross-validated with estimates from NLMIXED procedure (PROC NLMIXED) in Statistical Analysis System. Numerical data are provided for comparisons of results from MML/EM and PROC NLMIXED., Competing Interests: Declaration of Conflicting Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

The study describes for the first time the colocalization pattern of calbindin (CB) and cocaine- and amphetamine-regulated transcript (CART) in the mammillary body (MB) and anterior thalamic nuclei (ATN) - structures connected in a topographically organized manner by the mammillothalamic tract (mtt). Immunohistochemical study was performed on fetal (E40, E50, E60), newborn (P0) and postnatal (P20, P80) brains of the guinea pig, but the coexistence pattern of the substances was invariable throughout the examined developmental stages. CB and CART colocalized in the perikarya of the lateral part of the medial mammillary nucleus (MMl), whereas in its medial part (MMm) only CB was detected. In the mtt, which originates from the MB, both the substances were present and colocalized in single fibers. Next, fibers from the mtt spread toward the ATN in a particular way: fibers containing CB ran to both the anteromedial thalamic nucleus (AM) and anteroventral thalamic nucleus (AV), while fibers containing CART ran mostly to the latter one. In the ventral part of AV, CB and CART colocalized vastly in the neuropil. The lateral mammillary nucleus and anterodorsal thalamic nucleus were virtually devoid of CB- and CART-positive structures. Based on the known connections between the MB and ATN, we conclude that the studied substances may cooperate in the MMl-AV part of the axis and CB plays a significant role in the MMm-AM part., (Copyright © 2014. Published by Elsevier Ltd.)

MicroRNAs (miRNAs) are crucial negative regulators of gene expression at the post-transcriptional level. Next-generation sequencing technologies have identified a series of miRNA variants (named isomiRs). In this study, paralogous isomiR assemblies (from the miRNA locus) were systematically analyzed based on data acquired from deep sequencing data sets. Evolutionary analysis of paralogous (members in miRNA gene family in a specific species) and orthologues (across different animal species) miRNAs was also performed. The sequence diversity of paralogous isomiRs was found to be similar to the diversity of paralogous and orthologues miRNAs. Additionally, both isomiRs and paralogous/orthologues miRNAs were implicated in 5' and 3' ends (especially 3' ends), nucleotide substitutions, and insertions and deletions. Generally, multiple isomiRs can be produced from a single miRNA locus, but most of them had lower enrichment levels, and only several dominant isomiR sequences were detected. These dominant isomiR groups were always stable, and one of them would be selected as the most abundant miRNA sequence in specific animal species. Some isomiRs might be consistent to miRNA sequences in some species but not the other. Homologous miRNAs were often detected in similar isomiR repertoires, and showed similar expression patterns, while dominant isomiRs showed complex evolutionary patterns from miRNA sequences across the animal kingdom. These results indicate that the phenomenon of multiple isomiRs is not a random event, but rather the result of evolutionary pressures. The existence of multiple isomiRs enables different species to express advantageous sequences in different environments. Thus, dominant sequences emerge in response to functional and evolutionary pressures, allowing an organism to adapt to complex intra- and extra-cellular events., (© 2013.)