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Collapsibility is a practical and useful technique for dimension reduction in multidimensional contingency tables. In this paper, we consider marginal log‐linear models for studying collapsibility and related aspects in such tables. These models generalize ordinary log‐linear and multivariate logistic models, besides several others. First, we obtain some characteristic properties of marginal log‐linear parameters. Then we define collapsibility and strict collapsibility of these parameters in a general sense. Several necessary and sufficient conditions for collapsibility and strict collapsibility are derived based on simple functions of only the cell probabilities, which are easily verifiable. These include results for an arbitrary set of marginal log‐linear parameters having some common effects. The connections of strict collapsibility to various forms of independence of the variables are explored. We analyze some real‐life datasets to illustrate the above results on collapsibility and strict collapsibility. Finally, we obtain a result relating parameters with the same effect, but different margins for an arbitrary table, and demonstrate smoothness of marginal log‐linear models under collapsibility conditions. [ABSTRACT FROM AUTHOR]

Incomplete data, whether realized from nonresponse in survey data or counterfactual outcomes in observational studies, may lead to biased estimation of study variables. Nonresponse and selection bias may be mitigated with techniques that weight the incomplete data to match characteristics of the partially unobserved complete data. Inverse probability weighting is a widely used method in causal inference that relies on a propensity model to construct adjusted weights; whereas calibration is a common method used by survey statisticians to use constrained optimization to construct adjusted weights. This article reviews inverse probability weighting and entropy balancing calibration by distinguishing them in the statistical sense of variable balancing, extending propensity score construction to include generalized boosting models, and demonstrating the use of inverse probability weighting and calibration separately and together through a widely cited simulation study evaluation. This article is categorized under:Statistical and Graphical Methods of Data Analysis > SamplingData: Types and Structure > Categorical DataStatistical Learning and Exploratory Methods of the Data Sciences > Modeling Methods [ABSTRACT FROM AUTHOR]

Infidelity is a common reason couples seek therapeutic help as betrayed partners are often hurt and dismayed by their partners' decision to engage in an extradyadic relationship. Despite its common occurrence, there are very few empirical studies of the decision‐making process behind infidelity. To address this gap, the current study used grounded theory, a qualitative approach commonly used to develop theories from participants' experiences, to explore men's processes in deciding to engage in infidelity. Analysis of interviews with participants (n = 13) resulted in a grounded theory of decision‐making by cisgender men who participated in infidelity while in a committed, heterosexual relationship. The results suggest that the decision involves a continuous process of justification and rationalization. Major categories of the theory include the preaffair context, snowballing, motivated reasoning, and postaffair decisions. Clinical implications are also included. [ABSTRACT FROM AUTHOR]

We study existence and multiplicity of positive solutions of the following class of nonlocal scalar field equations: P${\mathcal {P}}$(−Δ)su+u=a(x)|u|p−1u+f(x)inRNu∈Hs(RN),$$\begin{equation} \hspace*{5pc} {\left\lbrace \begin{aligned} (-\Delta)^s u + u &= a(x) |u|^{p-1}u+f(x)\;\;\text{in}\;\mathbb {R}^{N}\\ u &\in H^{s}{\big(\mathbb {R}^{N}\big)}, \end{aligned} \right.} \end{equation}$$where s∈(0,1)$s \in (0,1)$, N>2s$N>2s$, 1

The purpose of this paper is to propose and explore a general framework within which a wide variety of model construction techniques from contemporary set theory can be subsumed. Taking our inspiration from presheaf constructions in category theory and Boolean ultrapowers, we will show that generic extensions, ultrapowers, extenders and generic ultrapowers can be construed as examples of a single model construction technique. In particular, we will show that Łoś's theorem can be construed as a specific case of Cohen's truth lemma, and we isolate the weakest conditions a filter must satisfy in order for the truth lemma to work. [ABSTRACT FROM AUTHOR]

Conceptual fragmentation is when a term assumed to have one meaning is found to have many. When these different definitions overlap in meaning and application confusion and wasted effort follows. "Attention" is such a fragmented term. The response to conceptual fragmentation is simple. Stop using the original term. Our reticence to do so reflects false beliefs about attention. "Attention" is not an old term, but a modern one. Its original meaning is not related to our contemporary intuitions. Attention is not a necessary concept; psychology made substantial progress, even in cognitive areas, during the years when its use was banished. Attention is just one among many examples of conceptual fragmentation in psychology. The root cause is a dearth of theory driving cognitive experimentation. Theoretical clarity is enhanced when fundamental concepts can be expressed in a mathematical form. When theories are stated in mathematical language it opens the door to rigorous cross‐domain comparisons using tools like category theory. This article is categorized under:Psychology > AttentionNeuroscience > Cognition [ABSTRACT FROM AUTHOR]

Although emergy theory has made progress in the field of eco‐compensation research, there is still a lack of review articles, summarizing the existing knowledge structure in this area of study. Accordingly, the objective of this paper is to provide a reference for researchers by characterizing the current status of emergy theory in the field of eco‐compensation and to establish the internal logic structure among existing studies, based upon a qualitative analysis of textual data. Inspired by the grounded theory, twelve concepts within five categories of emergy theory were extracted by open, axial, and selective coding of relevant literature. Concepts were extracted from the texts and categories were determined according to the inherent logical relationships among those concepts. The "knowledge structure model of emergy theory in the field of eco‐compensation" was constructed and the following five principal categories were identified: "emergy indicators system," the "integration of methods and theories," "research subjects," "calculation of compensation standards," and "research concerns." Moreover, core and supporting genera were also identified from these five axial codes. Finally, the research focuses and hotspots were explored according to the theoretical frameworks as indicated by the core and supporting genera. The findings of this paper provide a reference for researchers to further promote innovation in the application of emergy theory in the field of eco‐compensation. [ABSTRACT FROM AUTHOR]

We investigate degenerations of syzygy bundles on plane curves over p$p$‐adic fields. We use Mustafin varieties which are degenerations of projective spaces to find a large family of models of plane curves over the ring of integers such that the special fibre consists of multiple projective lines meeting in one point. On such models we investigate vector bundles whose generic fibre is a syzygy bundle and which become trivial when restricted to each projective line in the special fibre. Hence these syzygy bundles have strongly semistable reduction. This investigation is motivated by the fundamental open problem in p$p$‐adic Simpson theory to determine the category of Higgs bundles corresponding to continuous representations of the étale fundamental group of a curve. Faltings' p$p$‐adic Simpson correspondence and work of Deninger and the second author shows that bundles with Higgs field zero and potentially strongly semistable reduction fall into this category. Hence the results in the present paper determine a class of syzygy bundles on plane curves giving rise to a p$p$‐adic local system. We apply our methods to a concrete example on the Fermat curve suggested by Brenner and prove that this bundle has potentially strongly semistable reduction. [ABSTRACT FROM AUTHOR]

This paper develops and defends a novel version of a relatively neglected category of theory of the nature of happiness: the desire‐satisfaction theory. My account is similar in its fundamentals to Wayne Davis's theory of happiness‐as‐subjective‐desire‐satisfaction. After arguing that this is the best general way to proceed for the desire‐based approach, I develop an improved version of subjective desire satisfactionism in light of recent arguments in the happiness literature. [ABSTRACT FROM AUTHOR]

The application of parallel axes for the interactive visual analysis of multidimensional data is a widely used concept. While multidimensional data sets are commonly heterogeneous in nature, i.e. data items contain both numerical and categorical (including ordinal) attribute values, the use of parallel axes often assumes either numerical or categorical attributes. While Parallel Coordinates and their large variety of extensions focus on numerical data, Parallel Sets and related methods focus on categorical attributes. While both concepts allow for displaying heterogeneous data, no clear strategies have been defined for representing categories in Parallel Coordinates or discretization of continuous ranges in Parallel Sets. In practice, type conversion as a pre‐processing step can be used as well as coordinated views of numerical and categorical data visualizations. We evaluate traditional and state‐of‐the‐art approaches with respect to the interplay of categorical and numerical dimensions for querying probability‐based events. We also compare against a heterogeneous Parallel Coordinates/Parallel Set approach with a novel interface between categorical and numerical axes. We show that approaches for mapping categorical data to numerical axis representations can lead to lower accuracy in answering probability‐based questions and higher response times than hybrid approaches in multiple‐event scenarios. [ABSTRACT FROM AUTHOR]

State–space models (SSMs) are an important modeling framework for analyzing ecological time series. These hierarchical models are commonly used to model population dynamics, animal movement, and capture–recapture data, and are now increasingly being used to model other ecological processes. SSMs are popular because they are flexible and they model the natural variation in ecological processes separately from observation error. Their flexibility allows ecologists to model continuous, count, binary, and categorical data with linear or nonlinear processes that evolve in discrete or continuous time. Modeling the two sources of stochasticity separately allows researchers to differentiate between biological variation and imprecision in the sampling methodology, and generally provides better estimates of the ecological quantities of interest than if only one source of stochasticity is directly modeled. Since the introduction of SSMs, a broad range of fitting procedures have been proposed. However, the variety and complexity of these procedures can limit the ability of ecologists to formulate and fit their own SSMs. We provide the knowledge for ecologists to create SSMs that are robust to common, and often hidden, estimation problems, and the model selection and validation tools that can help them assess how well their models fit their data. We present a review of SSMs that will provide a strong foundation to ecologists interested in learning about SSMs, introduce new tools to veteran SSM users, and highlight promising research directions for statisticians interested in ecological applications. The review is accompanied by an in‐depth tutorial that demonstrates how SSMs can be fitted and validated in R. Together, the review and tutorial present an introduction to SSMs that will help ecologists to formulate, fit, and validate their models. [ABSTRACT FROM AUTHOR]

At week 24, the response of patients with CholU decreased because two patients lost response and two were lost to follow-up (57.1%), while it increased in patients with SD (83.3%), ColdU (80%), DPU (100%) and combined CIndU (100%) (Fig. Response was achieved in 26 (44.1%), 38 (65.5%) and 39 (81.3%) patients and complete response in 2 (3.4%), 11 (19%) and 12 (25%) patients at weeks 4, 12 and 24, respectively (Fig. GLO:3NZ/01oct21:jdv17385-fig-0001.jpg PHOTO (COLOR): 1 UCT score changes during treatment weeks with respect to CIndU types (a), treatment responses at week 4, 12 and 24 with respect to each CIndU type (b). [Extracted from the article]

Background: Minimally invasive adrenalectomy and advances in anaesthetic techniques have transformed surgery for phaeochromocytoma. This 17‐year review describes the evolution of phaeochromocytoma care in our unit. Methods: We performed a retrospective cohort review of all patients who underwent adrenalectomy for phaeochromocytoma from 2000 to 2016. Patients were divided into three time periods, early: 2000–2005 (n = 17), middle: 2006–2010 (n = 15) and late: 2011–2016 (n = 24). The posterior retroperitoneoscopic adrenalectomy was introduced in 2011. Demographics and clinicopathological details were extracted. Median values for nominal data were compared using Mann–Whitney U‐test. A chi‐squared test was used to compare categorical data. Results: Sixty‐one adrenalectomies were performed on 56 patients: 19 open, 17 laparoscopic and 20 posterior retroperitoneoscopic adrenalectomies. The median length of operation decreased from 135 to 90 min from the early to the late time period (P > 0.05). Length of stay decreased from a median of 5 days in the early group to 1 day in the late group (P = 0.01). A total of 94.1% of the early period patients were admitted to the intensive care unit compared to 30.4% of the late group (P = <0.01). Need for post‐operative vasopressors and blood transfusions was significantly reduced. Conclusion: Over the 17‐year period, the choice of operative technique has transitioned towards posterior retroperitoneoscopic adrenalectomy. Operative time, rate of intensive care unit admission, and admission length have all decreased without any increase in rates of complications. [ABSTRACT FROM AUTHOR]

Background: Each year, hundreds of thousands of children require sedation/anesthesia to facilitate MRI scans. Anesthetic techniques for accomplishing sedation/anesthesia vary widely between institutions and providers, with unclear implications for patient safety. Aims: We sought to establish trends in anesthetic practice for pediatric MRI sedation/anesthesia across a 7‐year period and determine rates of adverse events, considering technique used, age, and ASA physical classification status (ASA‐PS). Methods: Using established data resources, we analyzed 24 052 anesthetics performed by anesthesiologists for MRI scans between 5/1/2013 and 12/31/2019 on patients less than 18 years old, focusing on medications used, trends of use, and associated adverse events. Adverse events (hypoxia, hypotension, bradycardia) were defined by deviation from age norms and accessed via the electronic anesthetic record database. The Cochran‐Armitage test was used to assess trends over time in categorical data, and one‐way ANOVA was used to analyze continuous data. Multivariable logistic regression analysis was implemented to determine the independent associations between anesthetic technique and adverse events while adjusting for age, ASA‐PS, and weight. Results: The most significant trends noted were a decrease in "propofol‐only" anesthetic techniques and an increase in propofol and dexmedetomidine combination techniques. Mild desaturation (80–89% SpO2) occurred in 4.22% of cases with more significant hypoxia much rarer (0.44% of cases having desaturation <70% SpO2). Bradycardia occurred in 2.39% of cases and hypotension in 1.75% of cases. Major adverse events were rare. Conclusions: We provide the largest report of the nature of MRI sedation/anesthesia as practiced by anesthesiologists in a large children's hospital. We demonstrate that, even in a large system, anesthetic techniques are pliable and shift significantly over time. Our data also support a high level of safety within our system, despite a case mix likely higher in risk than those in most of the previously published studies. [ABSTRACT FROM AUTHOR]

Let α be an arbitrary infinite ordinal, and 2

Neutrophil to lymphocyte ratio (NLR) can predict mortality/complications in left ventricular assist device (LVAD) patients; however, the prognostic value of longitudinal NLR measurements has not been well studied. Here, we examine the mortality/complication incidence in patients with chronically increased NLR verses patients with acutely elevated NLR as a predictor of patient outcomes. This retrospective analysis included 102 patients who underwent LVAD implantation from 2016 to 2018 at a single center. The NLR was calculated at the time of surgery, and at 30 and 90 days after surgery. The NLR values were grouped into categorical data: low, normal (put in range), and high. Patients were classified in 2 groups based on change in their NLR values from surgery to 90 days; the H90 group had sustained increase of NLR over 90‐days and the N90 group had normalization of NLR at 90‐days. Actuarial survival the between study groups was measured using Kaplan–Meier curves. The N90 group had 50 patients (median age 58 (48–66) years, 21% female) at the time of LVAD placement. Group H90 had 52 patients (median age 64 (52–68) years, 16% female). Median age, body mass index (BMI), bilirubin, creatinine, and BNP at time of implant as well as type of device and implant strategy were comparable between the study groups. The post implant survival for N90 group was significantly better than the H90 group at 1 year (93% vs. 80%) and 2 years (90% vs. 67%) (log‐rank P =.001). Early post LVAD survival in patients with elevated NLR over 90 days postoperatively was significantly worse compared to patients who normalized the NLR at 90 days. [ABSTRACT FROM AUTHOR]

In geographic data analysis, one is often given point data of different categories (such as facilities of a university categorized by department). Drawing upon recent research on set visualization, we want to visualize category membership by connecting points of the same category with visual links. Existing approaches that follow this path usually insist on connecting all members of a category, which may lead to many crossings and visual clutter. We propose an approach that avoids crossings between connections of different categories completely. Instead of connecting all data points of the same category, we subdivide categories into smaller, local clusters where needed. We do a case study comparing the legibility of drawings produced by our approach and those by existing approaches. In our problem formulation, we are additionally given a graph G on the data points whose edges express some sort of proximity. Our aim is to find a subgraph G′ of G with the following properties: (i) edges connect only data points of the same category, (ii) no two edges cross, and (iii) the number of connected components (clusters) is minimized. We then visualize the clusters in G′. For arbitrary graphs, the resulting optimization problem, Cluster Minimization, is NP‐hard (even to approximate). Therefore, we introduce two heuristics. We do an extensive benchmark test on real‐world data. Comparisons with exact solutions indicate that our heuristics do astonishing well for certain relative‐neighborhood graphs. [ABSTRACT FROM AUTHOR]

While there are many visualization techniques for exploring numeric data, only a few work with categorical data. One prominent example is Parallel Sets, showing data frequencies instead of data points ‐ analogous to parallel coordinates for numerical data. As nominal data does not have an intrinsic order, the design of Parallel Sets is sensitive to visual clutter due to overlaps, crossings, and subdivision of ribbons hindering readability and pattern detection. In this paper, we propose a set of quality metrics, called ParSetgnostics (Parallel Sets diagnostics), which aim to improve Parallel Sets by reducing clutter. These quality metrics quantify important properties of Parallel Sets such as overlap, orthogonality, ribbon width variance, and mutual information to optimize the category and dimension ordering. By conducting a systematic correlation analysis between the individual metrics, we ensure their distinctiveness. Further, we evaluate the clutter reduction effect of ParSetgnostics by reconstructing six datasets from previous publications using Parallel Sets measuring and comparing their respective properties. Our results show that ParSetgostics facilitates multi‐dimensional analysis of categorical data by automatically providing optimized Parallel Set designs with a clutter reduction of up to 81% compared to the originally proposed Parallel Sets visualizations. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the effect of structured training on the cardiotocograph (CTG) interpretation skills of healthcare workers (HCWs) involved in obstetric care in a recourse constrained setting. Method: In all, 218 HCWs completed pre‐ and post‐intervention questionnaires. The intervention involved structured teaching on technical aspects of CTG monitoring, fetal physiology, and adaptation to stress, and a holistic approach to interpretation. Descriptive statistics were used to summarize demographic characteristics, frequencies, and percentages for categorical data. Results: Only 26.2% of participants felt that their pre‐graduate training was adequate; this was reflected by the poor baseline knowledge in CTG interpretation (56% misinterpreted) and lack of knowledge regarding technical aspects of CTG monitoring in 48.8% of participants. The training session led to a 65% improvement in technical aspects and interpretation. Those HCWs not receiving continuous training showed a more significant improvement (P < 0.001) and there was a 100% improvement in knowledge regarding the required documentation before commencing monitoring. Most (99.5%) HCWs acknowledged an improvement in knowledge, and 96.2% would participate in similar mandatory education sessions. Conclusion: These findings highlight the fact that training in CTG monitoring is warranted and desired by HCWs. It also supports the implementation of structured CTG education in resource‐constrained settings. SYNOPSIS: Structured training in cardiotocograph interpretation of healthcare workers involved in obstetric care in resource‐constrained environments improves their interpretation skills. [ABSTRACT FROM AUTHOR]

Clustering categorical sequences is a problem that arises in many fields. There is a few techniques available in this framework but none of them take into account the possible temporal character of transitions from one state to another. A mixture of Markov models is proposed, where transition probabilities are represented as functions of time. The corresponding expectation–maximization algorithm is discussed along with related computational challenges. The effectiveness of the proposed procedure is illustrated on the set of simulation studies, in which it outperforms four alternative approaches. The method is applied to major life event sequences from the British Household Panel Survey. As reflected by Bayesian Information Criterion, the proposed model demonstrates substantially better performance than its competitors. The analysis of obtained results and related transition probability plots reveals two groups of individuals: people with a conventional development of life course and those encountering some challenges. [ABSTRACT FROM AUTHOR]

Introduction: Low physical activity (PA) levels are associated with poor health‐related outcomes in Chronic Obstructive Pulmonary Disease (COPD). Thus, PA should be routinely assessed in clinical practice. Objectives: This study assessed the construct validity of the Brief Physical Activity Assessment Tool (BPAAT) for clinical use in COPD and explored differences in age, sex and COPD grades. Methods: After linguistic adaptation of the tool to Portuguese, 110 patients (66.4 ± 9.6yrs, 72.7% male, FEV1 = 59.3 ± 25.5%predicted) completed the BPAAT and received an accelerometer. The BPAAT includes two questions assessing the weekly frequency and duration of vigorous‐ and moderate‐intensity PA/walking, classifying individuals as insufficiently or sufficiently active. The BPAAT was correlated with accelerometry (moderate PA, MPA = 1952‐5724 counts‐per‐min [CPM]); vigorous PA, VPA = 5725‐∞CPM; moderate‐to‐vigorous PA, MVPA = 1952‐∞CPM; daily steps), through: Spearman's correlations (ρ) for continuous data; %agreement, Kappa, sensitivity and specificity, positive and negative predictive values (PPV, NPV) for categorical data. Results: The BPAAT identified 73.6% patients as "insufficiently active" and 26.4% as "sufficiently active". The BPAAT was weakly to moderately correlated with accelerometry (0.394 ≤ ρ ≤ 0.435, P < 0.05), except for VPA (P = 0.440). This was also observed in age (<65/≥65yrs), COPD grades (GOLD 1–2/3–4) and in male patients (0.363 ≤ ρ ≤ 0.518, P < 0.05 except for VPA). No significant correlations were found in female patients (P > 0.05). Agreement was fair to moderate (0.36 ≤ κ ≤ 0.43; 73.6% ≤ %agreement ≤ 74.5%; 0.50 ≤ sensitivity ≤ 0.52; 0.84 ≤ specificity ≤ 0.91, 0.55 ≤ PPV ≤ 0.79, 0.72 ≤ NPV ≤ 0.82). Conclusion: The BPAAT may be useful to screen patients' PA, independently of age and COPD grade, and identify male patients who are insufficiently active. Care should be taken when using this tool to assess vigorous PA or female patients. [ABSTRACT FROM AUTHOR]

Clinical trial mosaic plot example Mosaic plots are also suited for randomized trial data. Mosaic plots are a simple tool for visualizing, exploring, and displaying categorical data. [Extracted from the article]

Background: Whether video-assisted thoracoscopic surgery (VATS) sleeve lobectomy could be an alternative to traditional thoracotomy sleeve lobectomy in treating centrally located non-small cell lung cancer (NSCLC) remains unclear. Therefore, we conducted the first meta-analysis to compare the effects of VATS sleeve lobectomy with thoracotomy sleeve lobectomy. Methods: We systematically searched relevant studies from Pubmed, Embase, and Web of Science on May 12, 2020. Data for analysis included short-term outcomes (blood loss, lymph node dissected, operation time, hospital stay, complications) and long-term outcomes (3-year overall survival (OS) and progression-free survival (PFS) rates). We calculated the weighted mean differences (WMDs) for continuous data and risk ratio (RR) for pooling categorical data. Results: We finally included 5 retrospective cohort study consisting of 436 patients. VATS sleeve lobectomy yielded significantly less blood loss (WMD = −37.83; 95% confidence intervals (CIs) = [−58.56, −17.11]; P < 0.001) than thoracotomy sleeve lobectomy and comparable total number of dissected lymph node to thoracotomy sleeve lobectomy (WMD = − 0.07; 95%CI = [−1.14, 0.99]; P = 0.89). However, VATS sleeve lobectomy consumed significantly more operation time than thoracotomy sleeve lobectomy (WMD = 49.00; 95%CI = [14.67, 83.34]; P = 0.005). VATS sleeve lobectomy yielded significantly less postoperative hospital stay time than thoracotomy sleeve lobectomy (WMD = −1.68; 95%CI = [−2.98, −0.39]; P = 0.011) and comparable postoperative complication rate to thoracotomy sleeve lobectomy (RR = 0.84; 95%CI = [0.49, 1.44]; P = 0.52). Moreover, VATS sleeve lobectomy yielded comparable 3-year OS (RR = 1.08; 95%CI = [0.95, 1.22]; P = 0.23) and PFS (RR = 1.15; 95%CI = [0.96, 1.37]; P = 0.13) rates to thoracotomy sleeve lobectomy. No significant heterogeneities were observed. Conclusions: VATS sleeve lobectomy yielded less surgical trauma than thoracotomy sleeve lobectomy and improved postoperative recovery without compromising oncological prognosis. Even though VATS sleeve lobectomy may consume more operation time, it could be recommended as an alternative to thoracotomy sleeve lobectomy for treating centrally located NSCLC in carefully selected cases. [ABSTRACT FROM AUTHOR]

Objective: Categorical data analysis is relevant to suicide risk and prevention research that focuses on discrete outcomes (e.g., suicide attempt status). Unfortunately, results from these analyses are often misinterpreted and not presented in a clinically tangible manner. We aimed to address these issues and highlight the relevance and utility of categorical methods in suicide research and clinical assessment. Additionally, we introduce relevant basic machine learning methods concepts and address the distinct utility of the current methods.Method: We review relevant background concepts and pertinent issues with references to helpful resources. We also provide non-technical descriptions and tutorials of how to convey categorical statistical results (logistic regression, receiver operating characteristic [ROC] curves, area under the curve [AUC] statistics, clinical cutoff scores) for clinical context and more intuitive use.Results: We provide comprehensive examples, using simulated data, and interpret results. We also note important considerations for conducting and interpreting these analyses. We provide a walk-through demonstrating how to convert logistic regression estimates into predicted probability values, which is accompanied by Appendices demonstrating how to produce publication-ready figures in R and Microsoft Excel.Conclusion: Improving the translation of statistical estimates to practical, clinically tangible information may narrow the divide between research and clinical practice. [ABSTRACT FROM AUTHOR]

In this paper, we are interested in the following coupled critical Hartree system −Δu+λV1(x)u=α1u+βv+|x|−μ*|v|2μ*|u|2μ*−2uinℝN,−Δv+λV2(x)v=βu+α2v+|x|−μ*|u|2μ*|v|2μ*−2vinℝN,where λ > 0, β ≥ 0, α1,α2∈ℝ, 0 < μ < N, N ≥ 4, 2μ*=(2N−μ)/(N−2) are the upper critical exponents due to the Hardy‐Littlewood‐Sobolev inequality and the nonnegative potential function V1,V2∈C(ℝN,ℝ) has potential as well. By using variational methods, we prove the existence of ground state solutions and also characterize the asymptotic behavior of the solutions as the parameter λ goes to infinity. Furthermore, we are able to find the existence of multiple semitrivial weak solutions by the Lusternik‐Schnirelmann category theory. [ABSTRACT FROM AUTHOR]

Aim: Emergency colorectal surgery is associated with significant morbidity and mortality. Most general surgeons have a subspecialty, which forms the focus of their elective work, allowing development of specialist skill sets. The aim of this study was to assess the impact of consultant subspecialization on patient outcomes following emergency colorectal resections. Methods: Data were requested for all emergency admissions under a general surgeon between 1 January 2002 and 31 December 2016 within the north of England. These were acquired from individual Trusts following Caldicott approval. Data included demographics, diagnoses and any procedures undertaken. Patients were assigned to cohorts based on the subspecialist interest of the consultant they were under the care of. The primary outcome of interest was 30‐day postoperative mortality. Categorical data were compared with the chi‐squared test, and continuous data with the t test or ANOVA. A logistic regression model determined factors associated with 30‐day in‐hospital mortality. Results: Overall, 7648 emergency colorectal resections were performed with a 30‐day postoperative mortality of 13.8%. This was significantly lower if the responsible consultant was a colorectal surgeon compared with other general surgery subspecialties (11.8% vs. 15.2%, P < 0.001). This was significant on univariate analysis (OR 0.75, P < 0.001); however, following multivariable adjustment, this was not statistically significant (P = 0.380). The colorectal specialists had a higher laparoscopy rate than their colleagues—9.8% versus 6.8% (P < 0.001). Stoma rates were also lower (46.9% vs. 51.0%, P = 0.001) and anastomosis rates higher (55.9% vs. 49.3%, P < 0.001) amongst colorectal surgeons. Conclusion: These findings add to the growing body of evidence that patient outcomes may be improved by involving subspecialists in colorectal emergencies. [ABSTRACT FROM AUTHOR]

We show that certain classes of modules have universal models with respect to pure embeddings: Let R be a ring, T a first‐order theory with an infinite model extending the theory of R‐modules and KT=(Mod(T),≤pp) (where ⩽pp stands for "pure submodule"). Assume KT has the joint embedding and amalgamation properties. If λ|T|=λ or ∀μ<λ(μ|T|<λ), then KT has a universal model of cardinality λ. As a special case, we get a recent result of Shelah [28, 1.2] concerning the existence of universal reduced torsion‐free abelian groups with respect to pure embeddings. We begin the study of limit models for classes of R‐modules with joint embedding and amalgamation. We show that limit models with chains of long cofinality are pure‐injective and we characterize limit models with chains of countable cofinality. This can be used to answer [18, Question 4.25]. As this paper is aimed at model theorists and algebraists an effort was made to provide the background for both. [ABSTRACT FROM AUTHOR]

Introduction: Vancomycin pharmacokinetic data in critically ill patients receiving sustained low‐efficiency dialysis (SLED) is limited. Published data using vancomycin with intermittent hemodialysis and continuous renal replacement therapy may not be applicable to hybrid dialysis modalities such as SLED. Current drug references lack recommendations for vancomycin dosing in patients receiving SLED. Objective: The objective of this study was to determine vancomycin pharmacokinetics during SLED. Methods: A total of 20 patients who were critically ill with oliguric or anuric renal failure who received vancomycin and SLED were included in the study. Surrounding one SLED session, serum vancomycin blood samples were drawn before the initiation of SLED, at the termination of SLED, and 4 hours after completion of SLED treatment. Following this, patients received vancomycin, dosed to target a goal peak of 20–30 mcg/ml. A vancomycin peak level was drawn 1 hour after the end of the infusion. SLED treatment duration was at least 7 hours. Continuous data are reported as median (interquartile range) and categorical data as percentage. Results: The vancomycin elimination rate and half‐life were 0.051 hours (0.042–0.074 hours) and 13.6 hours (9.4–16.6 hours), respectively. SLED reduced vancomycin serum concentrations by 35.4% (31.5–43.8%), and vancomycin rebound was 9.8% (2.5–13.7%). The vancomycin dose administered post‐SLED was 1000 mg (875–1125 mg). For 18 patients, the patient‐specific volume of distribution was 0.88 L/kg (0.67–1.1 L/kg), vancomycin clearance was 3.5 L/hr (2.2–5.2 L/hr), and the area under the concentration‐time curve during the study time period was 280.8 mg·hr/L (254.7–297.3 mg·hr/L). Conclusion: Vancomycin is significantly removed during SLED with little rebound in serum concentrations 4 hours after completion of SLED. Based on study findings, patients who are critically ill require additional vancomycin dosing after each SLED session to maintain therapeutic post‐SLED vancomycin concentrations. Therapeutic drug monitoring of vancomycin is recommended during SLED. [ABSTRACT FROM AUTHOR]

Summary: In this study, we investigate the concept of the mean response for a treatment group mean as well as its estimation and prediction for generalized linear models with a subject‐wise random effect. Generalized linear models are commonly used to analyze categorical data. The model‐based mean for a treatment group usually estimates the response at the mean covariate. However, the mean response for the treatment group for studied population is at least equally important in the context of clinical trials. New methods were proposed to estimate such a mean response in generalized linear models; however, this has only been done when there are no random effects in the model. We suggest that, in a generalized linear mixed model (GLMM), there are at least two possible definitions of a treatment group mean response that can serve as estimation/prediction targets. The estimation of these treatment group means is important for healthcare professionals to be able to understand the absolute benefit vs risk. For both of these treatment group means, we propose a new set of methods that suggests how to estimate/predict both of them in a GLMMs with a univariate subject‐wise random effect. Our methods also suggest an easy way of constructing corresponding confidence and prediction intervals for both possible treatment group means. Simulations show that proposed confidence and prediction intervals provide correct empirical coverage probability under most circumstances. Proposed methods have also been applied to analyze hypoglycemia data from diabetes clinical trials. [ABSTRACT FROM AUTHOR]

Morphological variation (disparity) is almost invariably characterized by two non‐mutually exclusive approaches: (1) quantitatively, through geometric morphometrics; and (2) in terms of discrete, 'cladistic', or categorical characters. Uncertainty over the comparability of these approaches diminishes the potential to obtain nomothetic insights into the evolution of morphological disparity and the few benchmarking studies conducted so far show contrasting results. Here, we apply both approaches to characterizing morphology in the stem‐gnathostome clade Osteostraci in order to assess congruence between these alternative methods as well as to explore the evolutionary patterns of the group in terms of temporal disparity and the influence of phylogenetic relationships and habitat on morphospace occupation. Our results suggest that both approaches yield similar results in morphospace occupation and clustering, but also some differences indicating that these metrics may capture different aspects of morphology. Phylomorphospaces reveal convergence towards a generalized 'horseshoe'‐shaped cranial morphology and two strong trends involving major groups of osteostracans (benneviaspidids and thyestiids), which probably reflect adaptations to different lifestyles. Temporal patterns of disparity obtained from categorical and morphometric approaches appear congruent, however, disparity maxima occur at different times in the evolutionary history of the group. The results of our analyses indicate that categorical and continuous data sets may characterize different patterns of morphological disparity and that discrepancies could reflect preservational limitations of morphometric data and differences in the potential of each data type for characterizing more or less inclusive aspects of overall phenotype. [ABSTRACT FROM AUTHOR]

Background: Operating room (OR) costs are a large portion of healthcare expenses. This study evaluates the impact of a surgeon‐targeted surgical receipt cost feedback system on OR supply costs in sinonasal surgery and individual components contributing to procedural cost. Methods: Itemized weekly surgical receipts detailing individual case supply costs were analyzed before and after the implementation of a non‐incentivized surgeon cost feedback system between January 2017 and June 2019. Supply cost data collected 15 months prior to intervention was compared to cost data 15 months after implementation of the weekly automated receipt dissemination to surgeons. Chi square test was used for categorical data and the Wilcoxon test was used to compare change in cost. Univariate and mediation analyses were performed to assess variables impacting cost. Results: Of 502 sinonasal procedures analyzed, 239 were before and 264 after cost feedback implementation. There were no significant differences in age/gender, or indication for surgery. The median OR supply cost decreased from $1229.64 to $1097.22 (p = 0.02) after receipt implementation. There were effects of procedure type (p = 0.02), circulating nurse specialization (p < 0.001), steroid eluting stent (p = 0.002), and sinus drill (p < 0.001) on cost. Mediation analysis confirmed full mediation by decreasing use of steroid‐eluting stents. Conclusion: Surgeon cost feedback in the form of individualized OR surgical receipts is an effective model to reduce supply cost per case in sinonasal surgery. [ABSTRACT FROM AUTHOR]

Missing data is a serious issue in software engineering because it can lead to information loss and bias in data analysis. Several imputation techniques have been proposed to deal with both numerical and categorical missing data. However, most of those techniques used is simple reuse techniques originally designed for numerical data, which is a problem when the missing data are related to categorical attributes. This paper aims (a) to propose a new fuzzy case‐based reasoning (CBR) imputation technique designed for both numerical and categorical data and (b) to evaluate and compare the performance of the proposed technique with the k‐nearest neighbor (KNN) imputation technique in terms of error and accuracy under different missing data percentages and missingness mechanisms in four software engineering data sets. The results suggest that the proposed fuzzy CBR technique outperformed KNN in terms of imputation error and accuracy regardless of the missing data percentage, missingness mechanism, and data set used. Moreover, we found that the missingness mechanism has an important impact on the performance of both techniques. The results are encouraging in the sense that using an imputation technique designed for both categorical and numerical data is better than reusing methods originally designed for numerical data. [ABSTRACT FROM AUTHOR]

Background: Despite rapid and intensive treatments with therapeutic plasma exchange (TPE) and immunosuppression, immune thrombotic thrombocytopenic purpura (TTP) patients are at risk of disease exacerbation, i.e., early recurrence of TTP within 30 days of achieving treatment response. TPE taper, a practice of performing additional TPE procedures after achieving treatment response, is commonly performed for decreasing exacerbations, although no evidence supports this practice.Study Design and Methods: In this prospective observational investigation over four years, our center switched its standard of care for treating all TTP patients from not performing TPE taper after achieving treatment response (i.e., no-taper cohort) to performance of TPE taper (i.e., yes-taper cohort) to characterize impacts on exacerbations. Continuous and categorical data were analyzed by Mann-Whitney, Fisher's exact, and log-rank tests; significance was defined as p < 0.05.Results: The two cohorts were well matched and had no significant differences in demographics, presentation laboratory values, or TTP history (p > 0.05 for all). The yes-taper cohort of 26 patients with 29 consecutive episodes did not have a significantly different exacerbation rate from the no-taper cohort of 24 patients with 27 consecutive episodes (exacerbation rates of 37.9% vs. 33.3%, respectively; p = 0.78); however, treatment-related complications directly attributed to the TPE procedures, blood products, or central venous catheters were significantly greater in the yes-taper cohort (nine vs. one events, respectively; p = 0.01).Conclusion: Since TPE taper did not reduce exacerbations in our TTP patients, we no longer advocate for TPE taper and have reverted to our original standard of care. [ABSTRACT FROM AUTHOR]

In an earlier article, Gordon Drummond summarized ongoing changes in how statistics are being used in experimental physiology. He described the near‐ubiquitous use of the P value, cautioning against declaring an analysis 'statistically significant'. He mentioned alternative approaches, including Bayesian and likelihood approaches. This article focuses on the latter approach, although I initially take another look at the P value. Then the likelihood approach is introduced with a very artificial example to enable the concept to be grasped easily. Next, a more realistic example is described, with associated calculations. A further example using real categorical data is explained, showing how it relates to and is superior to the oft‐used χ2 test. A final discussion reveals that the likelihood approach, although mathematically and statistically accurate, is poorly supported by literature and training. [ABSTRACT FROM AUTHOR]

Objective: The mechanisms by which antiepileptic drugs (AEDs) cause birth defects (BDs) are unknown. Data suggest that AED-induced BDs may result from a genome-wide increase of de novo variants in the embryo, a mechanism that we investigated.Methods: Whole exome sequencing data from child-parent trios were interrogated for de novo single-nucleotide variants/indels (dnSNVs/indels) and de novo copy number variants (dnCNVs). Generalized linear models were applied to assess de novo variant burdens in children exposed prenatally to AEDs (AED-exposed children) versus children without BDs not exposed prenatally to AEDs (AED-unexposed unaffected children), and AED-exposed children with BDs versus those without BDs, adjusting for confounders. Fisher exact test was used to compare categorical data.Results: Sixty-seven child-parent trios were included: 10 with AED-exposed children with BDs, 46 with AED-exposed unaffected children, and 11 with AED-unexposed unaffected children. The dnSNV/indel burden did not differ between AED-exposed children and AED-unexposed unaffected children (median dnSNV/indel number/child [range] = 3 [0-7] vs 3 [1-5], p = 0.50). Among AED-exposed children, there were no significant differences between those with BDs and those unaffected. Likely deleterious dnSNVs/indels were detected in 9 of 67 (13%) children, none of whom had BDs. The proportion of cases harboring likely deleterious dnSNVs/indels did not differ significantly between AED-unexposed and AED-exposed children. The dnCNV burden was not associated with AED exposure or birth outcome.Interpretation: Our study indicates that prenatal AED exposure does not increase the burden of de novo variants, and that this mechanism is not a major contributor to AED-induced BDs. These results can be incorporated in routine patient counseling. ANN NEUROL 2020;87:897-906. [ABSTRACT FROM AUTHOR]

The paper compares the final run of Integrated Multi-Satellite Retrieval of Global Precipitation Mission (IMERG) products with India Meteorological Department (IMD) gridded data over the Indian land mass during the southwest monsoon period (June-September) in the period 2014-2017. Spatiotemporal variations of the IMERG are evaluated with IMD rainfall by employing different statistical techniques, and the capability of the IMERG is examined using the categorical skill metrics. A region in central India is the focus in order to study the southwest monsoon's static and dynamic characteristics, such as rainfall distribution and monsoon activity, using the IMERG in conjunction with IMD rainfall data sets. The integrated condensation rate (ICR) was estimated using the specific humidity profiles, and it correlated with the IMERG and IMD rainfall. The IMERG is found to be a potential source for adequately reflecting the ground gauge-gridded data of categorical rainfall amounts, from very light rain (trace-2.4 mm) to very heavy rain (about 115.6-204.4 mm). However, the IMERG does not reflect satisfactorily the extreme heavy rain events (≥ 204.5 mm·day-1) during the study period. The significant correlation between IMERG/IMD rainfall and the ICR suggests that improved adjustments methods are required for better results when depicting accurate extreme heavy rainfall events by the IMERG. [ABSTRACT FROM AUTHOR]

Aim: Perforated appendicitis has poorer clinical outcomes compared to non-perforated appendicitis. However, accurate outcome comparisons in research and clinical audits are challenged by its wide spectrum of manifestation. Previous attempts at the classification of severity have been complex and difficult to reproduce. In our study, we used another institution's (Jones et al., TX, USA) previously described simple classification system of peritoneal contamination and examined its usefulness in predicting outcomes.Methods: With ethical approval, we retrospectively reviewed the records of all paediatric patients operated at our institution for perforated appendicitis from 2016 to 2017. Patient demographics, intra-operative and histological findings, post-operative outcomes and length of stay were collected. Patients were categorised into group 1 (purulence in right lower quadrant only) and group 2 (contamination in two or more quadrants). Post-operative complications were defined as procedure-related (e.g. post-operative ileus, intra-abdominal abscess, visceral injury) and non-procedure-related (e.g. bronchospasm). Statistical analysis using χ2 tests for categorical data and Mann-Whitney U-tests for non-parametric continuous variables was performed, with a significance of P < 0.05.Results: There were 134 eligible patients. We excluded 19 with incomplete data, leaving 115 for analysis, of which 69 (60%) were in group 2. Those in group 2 had a longer stay (P = 0.005) and more post-operative complications (P = 0.001), particularly procedure-related events (P = 0.006). There were no differences in age (P = 0.182), gender (P = 0.876), readmission rate (P = 0.317) and non-procedure-related post-operative complications (0.152).Conclusion: This simple classification of perforated appendicitis appears to differentiate clinical outcomes well, particularly for iatrogenic morbidity, making it useful for operative preparation and outcomes research. [ABSTRACT FROM AUTHOR]

Longitudinal‐ordered categorical data, common in clinical trials, can be effectively analyzed with nonlinear mixed effect models. In this article, we systematically evaluated the performance of three different models in longitudinal muscle spasm adverse event (AE) data obtained from a clinical trial for vismodegib: a proportional odds (PO) model, a discrete‐time Markov model, and a continuous‐time Markov model. All models developed based on weekly spaced data can reasonably capture the proportion of AE grade over time; however, the PO model overpredicted the transition frequency between grades and the cumulative probability of AEs. The influence of data frequency (daily, weekly, or unevenly spaced) was also investigated. The PO model performance reduced with increased data frequency, and the discrete‐time Markov model failed to describe unevenly spaced data, but the continuous‐time Markov model performed consistently well. Clinical trial simulations were conducted to illustrate the muscle spasm resolution time profile during the 8‐week dose interruption period after 12 weeks of continuous treatment. [ABSTRACT FROM AUTHOR]

New treatments that are noninferior or equivalent to-but not necessarily superior to-the reference treatment may still be beneficial to patients because they have fewer side effects, are more convenient, take less time, or cost less. The noninferiority test is widely used in medical research to provide guidance in such situation. In addition, categorical variables are frequently encountered in medical research, such as in studies involving patient-reported outcomes. In this paper, we develop a noninferiority testing procedure for correlated ordinal categorical variables based on a paired design with a latent normal distribution approach. Misclassification is frequently encountered in the collection of ordinal categorical data; therefore, we further extend the procedure to account for misclassification using information in the partially validated data. Simulation studies are conducted to investigate the accuracy of the estimates, the type I error rates, and the power of the proposed procedure. Finally, we analyze one substantive example to demonstrate the utility of the proposed approach. [ABSTRACT FROM AUTHOR]

Engineering design‐based STEM integration is one potential model to help students integrate content and practices from all of the STEM disciplines. In this study, we explored the intersection of two aspects of pre‐college STEM education: the integration of the STEM disciplines, and the NGSS practice of engaging in argument from evidence within engineering. Specifically, our research question was: While generating and justifying solutions to engineering design problems in engineering design‐based STEM integration units, what STEM content do elementary and middle school students discuss? We used naturalistic inquiry to analyze student team audio recordings from seven curricular units in order to identify the variety of STEM content present as students justified their design ideas and decisions (i.e., used evidence‐based reasoning). Within the four disciplines, fifteen STEM content categories emerged. Particularly interesting were the science and mathematics categories. All seven student teams used unit‐based science, and five used unit‐based mathematics, to support their design ideas. Five teams also applied science and/or mathematics content that was outside the scope of the units' learning objectives. Our results demonstrate that students integrated content from all four STEM disciplines when justifying engineering design ideas and solutions, thus supporting engineering design‐based STEM integration as a curricular model. [ABSTRACT FROM AUTHOR]

Preference data, such as Likert scale data, are often obtained in questionnaire‐based surveys. Clustering respondents based on survey items is useful for discovering latent structures. However, cluster analysis of preference data may be affected by response styles, that is, a respondent's systematic response tendencies irrespective of the item content. For example, some respondents may tend to select ratings at the ends of the scale, which is called an 'extreme response style'. A cluster of respondents with an extreme response style can be mistakenly identified as a content‐based cluster. To address this problem, we propose a novel method of clustering respondents based on their indicated preferences for a set of items while correcting for response‐style bias. We first introduce a new framework to detect, and correct for, response styles by generalizing the definition of response styles used in constrained dual scaling. We then simultaneously correct for response styles and perform a cluster analysis based on the corrected preference data. A simulation study shows that the proposed method yields better clustering accuracy than the existing methods do. We apply the method to empirical data from four different countries concerning social values. [ABSTRACT FROM AUTHOR]

Inductive logic programming (ILP) induces concepts from a set of positive examples, a set of negative examples, and background knowledge. ILP has been applied on tasks such as natural language processing, finite element mesh design, network mining, robotics, and drug discovery. These data sets usually contain numerical and multivalued categorical attributes; however, only a few relational learning systems are capable of handling them in an efficient way. In this paper, we present an evolutionary approach, called Grouping and Discretization for Enriching the Background Knowledge (GDEBaK), to deal with numerical and multivalued categorical attributes in ILP. This method uses evolutionary operators to create and test numerical splits and subsets of categorical values in accordance with a fitness function. The best subintervals and subsets are added to the background knowledge before constructing candidate hypotheses. We implemented GDEBaK embedded in Aleph and compared it to lazy discretization in Aleph and discretization in Top‐down Induction of Logical Decision Trees (TILDE) systems. The results obtained showed that our method improves accuracy and reduces the number of rules in most cases. Finally, we discuss these results and possible lines for future work. [ABSTRACT FROM AUTHOR]

Unaccounted population stratification can lead to false‐positive findings and can mask the true association signals in identification of disease‐related genetic variants. The computational simplicity of principal component analysis (PCA) makes it a widely used method for population stratification adjustment. However, given that genotype data are generally represented by numerical values 0, 1, and 2, corresponding to the number of minor alleles, it is more reasonable to consider genotype data as categorical data. Because PCA is inherently only suitable for continuous variables, it is not appropriate to directly apply PCA on genotype data. Second, although common variants have been extensively studied, little is known about the stratification of rare variants and its impact on association tests. Over the last decade, there has been a shift in the genome‐wide association studies toward studying low‐frequency (minor allele frequency [MAF] between 0.01 and 0.05) and rare (MAF less than 0.01) variants, which are now widely reputed as complex trait determinants. The fact that rare variants are not stratified in the same way as common variants necessitates the development of statistical methods that can capture stratification patterns for low‐frequency and rare variants. To address these limitations, we investigate performances of generalized PCA and similarity‐matrix‐based PCA methods to detect underlying structures for rare and common variants. We demonstrate, through simulated and real datasets, that a special case of generalized PCA (i.e., logistic PCA) is able to adjust for population stratification in rare variants much more effectively than standard PCA while their performances are comparable for common variants. [ABSTRACT FROM AUTHOR]

Background: Coaches, athletic trainers (ATCs), and parents/guardians (parents) are important contributors to the proper identification and management of concussions in student-athletes. However, there are limited studies on the identification of concussion knowledge gaps that will help inform educational efforts and improve concussion outcomes in these groups.Objective: To identify gaps and factors influencing concussion knowledge for high school athletics.Design: Survey.Setting: Public, private, and recreational leagues in New Jersey.Participants: 41 coaches, 34 ATCs, and 65 parents of high school student-athletes.Methods: A 17-item online survey examining concussion knowledge was distributed to coaches, ATCs, and parents. Analyses included ANOVA for between-group comparisons of continuous variables and Pearson's correlations for categorical data.Main Outcome Measurements: Demographics, concussion knowledge, application of knowledge, access to educational materials, and confidence in the ability to identify concussions.Results: Significant between-group differences were found for overall knowledge (F[2137] = 11.0, P < .001), factual knowledge (F[2137] = 8.7, P < .001), and application of knowledge (F[2137] = 3.5, P = .03), with parents scoring lower. Coaches, ATCs, and parents had gaps in factual knowledge of baseline testing scores and identification regarding symptom severity. More coaches (73.2%) and ATCs (97.1%) felt confident in concussion knowledge compared with parents (31.3%; P < .001). All groups thought mandatory education, new law, and guidelines were positive in promoting better care of student-athletes.Conclusions: Knowledge gaps were identified in all groups. Educational programs for these groups should consider including targeted techniques, including vignettes, to illustrate application of concussion knowledge.Level Of Evidence: III. [ABSTRACT FROM AUTHOR]

Many clinical or prevention studies involve missing or censored outcomes. Maximum likelihood (ML) methods provide a conceptually straightforward approach to estimation when the outcome is partially missing. Methods of implementing ML methods range from the simple to the complex, depending on the type of data and the missing-data mechanism. Simple ML methods for ignorable missing-data mechanisms (when data are missing at random) include complete-case analysis, complete-case analysis with covariate adjustment, survival analysis with covariate adjustment, and analysis via propensity-to-be-missing scores. More complex ML methods for ignorable missing-data mechanisms include the analysis of longitudinal dropouts via a marginal model for continuous data or a conditional model for categorical data. A moderately complex ML method for categorical data with a saturated model and either ignorable or nonignorable missing-data mechanisms is a perfect fit analysis, an algebraic method involving closed-form estimates and variances. A complex and flexible ML method with categorical data and either ignorable or nonignorable missing-data mechanisms is the method of composite linear models, a matrix method requiring specialized software. Except for the method of composite linear models, which can involve challenging matrix specifications, the implementation of these ML methods ranges in difficulty from easy to moderate. [ABSTRACT FROM AUTHOR]

Introduction: This study gathered information about life outside of the course for undergraduates studying at the School of Dentistry, Cardiff University. The aim was to explore how these external factors to the course may affect an individual's academic performance and well‐being. Materials and Methods: A cross‐sectional study design was used. An online questionnaire designed for the purpose of the study was used to capture (quantitative and qualitative) data. Questions with dichotomous options, a range of statements with Likert scales (level of agreement) and open (free‐text) questions were used. Data were analysed in SPSS using simple descriptive statistics and frequency distributions. Spearman's Rho was used to explore relationships for scaled categorical data. Content analysis was used for qualitative data. Results: Two‐thirds (n = 69, 63%) of participants reported being very stressed about their studies in the previous 12 months. The majority felt that external factors to their course (eg, lack of sleep, health issues, financial concerns, hobbies and issues with friends) had impacted on their academic lives with only 9% (n = 10) stating that their lives outside dentistry had no effect. Discussion: Those who felt able to pursue hobbies and activities reported a better work‐life balance and less stress. Questions about pursuing hobbies and sleep may help identify students at risk of being stressed or who may benefit from additional support in order to achieve a better work‐life balance. Conclusion: This study has highlighted key areas for further investigation and opportunities for improving support to reduce student stress and improve well‐being. [ABSTRACT FROM AUTHOR]

Better known by their remarkable forelimb morphology, bats are also unique among mammals with respect to their hindlimbs. Their legs are rotated through 180°, generally reduced in size, and in some extant taxa particular bones (e.g. fibula) can even be absent. The femur is the main leg bone, but to date few bat studies have considered its morphology in detail, none in a wide‐scale comparative study. Yangochiroptera is the largest bat taxon, spans nearly three orders of magnitude in body mass, and is highly diverse both in ecology and behavior, representing a good model for comparative analyses. Here, we describe the anatomy of the femur in a large sample of yangochiropteran bats (125 species, 70 genera, and 12 families), and explore major trends of morphological variation and scaling patterns in this bone. We used 13 categorical characters in the anatomical description and five linear dimensions in the quantitative analyses. Based on the categorical data, each family studied here was diagnosed, and those from the Neotropical region were included in an identification key. From the phylogenetic principal component analysis (pPCA) we showed that, in addition to size, major axes of variation in bat femur are related to robusticity and head morphology, features that are clearly distinct among some families. We also generated a phylomorphospace based on pPCA scores, highlighting convergences in femur shape. Molossidae, Mystacinidae, and Desmodontinae were grouped based on their greater robusticity, a pattern that was also recovered from categorical data. In these families, we found anatomical features (e.g. presence of tubercles and posterior ridges on the greater trochanter, long or medially/distally displaced lateral ridges on the shaft) that are well‐known from their functional link with quadrupedal locomotion. Using phylogenetic regressions, we found out that compared with body mass, femur length scaled with negative allometry, as expected, but that femur width scaled isometrically, counter to expectations. As a result, robusticity index (the ratio of width to length), scaled with positive allometry – larger bats tended to have more robust hindlimbs. At species level, our most remarkable finding was related to Myotis simus, which presented the most robust femur (for its size) among yangochiropterans. Our results reinforce the informative potential of the chiropteran femur from both taxonomic and functional perspectives. Furthermore, the allometric trends seen in this bone may help understand the strategies adopted by flying vertebrates to deal with the high energetic cost of flight and, at the same time, evolve diversified foraging behaviors. [ABSTRACT FROM AUTHOR]

Background: Merkel cell carcinoma (MCC) is a rare but aggressive primary cutaneous carcinoma with high mortality rates. The present study intends to delineate the epidemiological profile of patients with MCC seen at the Clinics Hospital of the Medical School at the University of São Paulo, Brazil, and its association with Merkel cell polyomavirus (MCPyV). Methods: This is a retrospective study. A search was performed in the hospital's medical index for all cases of MCC from January 1994 to December 2012. Among patients with MCC, the available tumoral skin specimens were analyzed with two different techniques of polymerase chain reaction (PCR) (conventional and real‐time) for detection of MCPyV DNA. Additionally, paraffin‐embedded samples of patients with non‐MCC skin cancers were also analyzed. Analyses suitable for categorical data (i.e., x² of Fisher) were used to compare the proportion of patients in each group. Results: Nineteen patients with MCC and 20 patients with non‐MCC skin cancers entered the study. All MCC samples available (13) tested positive for the presence of MCPyV DNA; however, in the non‐MCC skin cancer samples, the MCPyV DNA was detected in 4 of 20 samples (20%). MCPyV DNA detection rate was higher in patients with MCC than in the other group, and its analysis was statistically significant (P < 0.01). Conclusions: This study demonstrates the association of MCPyV in Brazilian patients with MCC. However, further studies are necessary to determine the exact involvement of MCPyV in MCC pathogenesis and to define the significance of viral DNA detection in non‐MCC skin cancers. [ABSTRACT FROM AUTHOR]

Objectives: To assess clinical follow‐up data over 24 months, comparing the use of a curved vs straight stylet in patients undergoing sacral neuromodulation using the standardized tined lead implantation technique. Patients and Methods: We conducted a single tertiary‐centre, prospective study between August 2013 and June 2015 involving 40 patients with overactive bladder and 15 with non‐obstructive urinary retention refractory to first‐line treatment. The primary outcome was successful tined lead procedure according to intention‐to‐treat analyses at 12 and 24 months. The secondary outcome was number of optimal electrode configurations during programming. Statistical analysis was performed using plain non‐parametric tests for numerical and categorical data. Results: Successful tined lead procedures were achieved in 33 of 35 patients (94%) implanted with the curved stylet compared with 13 of 20 patients (65%) implanted with the straight stylet (P = 0.005). Intention‐to‐treat analyses at 12 and 24 months showed success rates of 94% and 91%, respectively, in the curved stylet group vs 65% and 45%, respectively, in the straight stylet group (P = 0.002 and P < 0.001). In the curved stylet group, 60% and 25% of the electrode configurations were considered optimal and poor, respectively, vs 40% and 37%, respectively, in the straight stylet group (P < 0.001). Conclusions: The use of the standardized implantation technique with the curved stylet led to more successful tined lead procedures, better success rates after 2 years of follow‐up and a greater number of optimal electrode configurations when compared to use of the straight stylet. [ABSTRACT FROM AUTHOR]

Models were developed to characterize the relationship between afatinib exposure and diarrhea and rash/acne adverse event (AE) trajectories, and their predictive ability was assessed. Based on pooled data from seven phase II/III clinical studies including 998 patients, mixed‐effects models for ordered categorical data were applied to describe daily AE severity. Clinical trial simulation aided by trial execution models was used for internal and external model evaluation. The final exposure‐safety model consisted of longitudinal logistic regression models with first‐order Markov elements for both AEs. Drug exposure was included as daily area under the concentration‐time curve (AUC), and drug effects on the AEs were correlated. Clinical trial simulation allowed adequate prediction of maximum AE grades and AE severity time courses but overestimated the proportion of AE‐dependent dose reductions and discontinuations. Both diarrhea and rash/acne were correlated with afatinib exposure. The developed modeling framework allows a prospective comparison of dosing strategies and study designs with respect to safety. [ABSTRACT FROM AUTHOR]