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In line with the journal volume's theme, this essay considers lessons from the past and visions for the future of test validity. In the first part of the essay, a description of historical trends in test validity since the early 1900s leads to the natural question of whether the discipline has progressed in its definition and description of test validity. There is no single agreed-upon definition of test validity; however, there is a marked coalescing of explanation-centered views at the meta-level. The second part of the essay focuses on the author's development of an explanation-focused view of validity theory with aligned validation methods. The confluence of ideas that motivated and influenced the development of a coherent view of test validity as the explanation for the test score variation and validation is the process of developing and testing the explanation guided by abductive methods and inference to the best explanation. This description also includes a new re-interpretation of true scores in classical test theory afforded by the author's measure-theoretic mental test theory development--for a particular test-taker, the variation in observed test-taker scores includes measurement error and variation attributable to the different ecological testing settings, which aligns with the explanation-focused view wherein item and test performance are the object of explanatory analyses. The final main section of the essay describes several methodological innovations in explanation-focused validity that are in response to the tensions and changes in assessment in the last 25 years.

Multiple sclerosis (MS) is a complex disease of the CNS thought to require an environmental trigger. Gut dysbiosis is common in MS, but specific causative species are unknown. To address this knowledge gap, we used sensitive and quantitative PCR detection to show that people with MS were more likely to harbor and show a greater abundance of epsilon toxin-producing (ETX-producing) strains of C. perfringens within their gut microbiomes compared with individuals who are healthy controls (HCs). Isolates derived from patients with MS produced functional ETX and had a genetic architecture typical of highly conjugative plasmids. In the active immunization model of experimental autoimmune encephalomyelitis (EAE), where pertussis toxin (PTX) is used to overcome CNS immune privilege, ETX can substitute for PTX. In contrast to PTX-induced EAE, where inflammatory demyelination is largely restricted to the spinal cord, ETX-induced EAE caused demyelination in the corpus callosum, thalamus, cerebellum, brainstem, and spinal cord, more akin to the neuroanatomical lesion distribution seen in MS. CNS endothelial cell transcriptional profiles revealed ETX-induced genes that are known to play a role in overcoming CNS immune privilege. Together, these findings suggest that ETX-producing C. perfringens strains are biologically plausible pathogens in MS that trigger inflammatory demyelination in the context of circulating myelin autoreactive lymphocytes.

The pancreatic islets are composed of discrete hormone-producing cells that orchestrate systemic glucose homeostasis. Here we identify subsets of beta cells using a single-cell transcriptomic approach. One subset of beta cells marked by high CD63 expression is enriched for the expression of mitochondrial metabolism genes and exhibits higher mitochondrial respiration compared with CD63lo beta cells. Human and murine pseudo-islets derived from CD63hi beta cells demonstrate enhanced glucose-stimulated insulin secretion compared with pseudo-islets from CD63lo beta cells. We show that CD63hi beta cells are diminished in mouse models of and in humans with type 2 diabetes. Finally, transplantation of pseudo-islets generated from CD63hi but not CD63lo beta cells into diabetic mice restores glucose homeostasis. These findings suggest that loss of a specific subset of beta cells may lead to diabetes. Strategies to reconstitute or maintain CD63hi beta cells may represent a potential anti-diabetic therapy.

The objective of the research was to investigate the effect of Saccharomyces cerevisiae supplementation on some acute-phase proteins, haptoglobin and all electrophoretic parameters in young Charolaise bulls.

Poor treatment adherence and lack of self-care behaviors are significant contributors to hospital readmissions of people with heart failure (HF). A transitional program with non-invasive telemonitoring may help sustain patients and their caregivers to timely recognize signs and symptoms of exacerbation.We will conduct a Randomized Clinical Trial (RCT) to evaluate the feasibility and acceptability of a 6-month supportive intervention for patients discharged home after cardiac decompensation. Forty-five people aged 65 years and over will be randomized to either receive a supportive intervention in addition to standard care, which combines nurse-led telephone coaching and a home-based self-monitoring vital signs program, or standard care alone. Four aspects of the feasibility will be assessed using a mixed-methods approach: process outcomes (e.g., recruitment rate), resources required (e.g., adherence to the intervention), management data (e.g., completeness of data collection), and scientific value (e.g. 90- and 180-day all-cause and HF-related readmissions, self-care capacity, quality of life, psychological well-being, mortality, etc.). Participants will be interviewed to explore preferences and satisfaction with the intervention. The study is expected to provide valuable insight into the design of a definitive RCT.

Magnetic Resonance imaging based Electrical Properties Tomography (MR-EPT) is a non-invasive technique that measures the electrical properties (EPs) of biological tissues. In this work, we present and numerically investigate the performance of an unrolled, physics-assisted method for 2D MR-EPT reconstructions, where a cascade of Convolutional Neural Networks is used to compute the contrast update. Each network takes in input the EPs and the gradient descent direction (encoding the physics underlying the adopted scattering model) and returns as output the updated contrast function. The network is trained and tested in silico using 2D slices of realistic brain models at 128 MHz. Results show the capability of the proposed procedure to reconstruct EPs maps with quality comparable to that of the popular Contrast Source Inversion-EPT, while significantly reducing the computational time.

Italy has a long history of sheep breeding and counts several local populations that may represent a unique source of genetic diversity. Among these, Nera del Mela is a sheep genetic resource historically reared in Sicily but not officially recognised as a breed. In this study, we genotyped 36 individuals of Nera del Mela using the OvineSNP50K array, in order to estimate the genetic diversity and evaluate the population structure and relatedness with other Italian sheep breeds. Genetic diversity indices, and inbreeding estimated from runs of homozygosity (FROH) revealed a moderate level of variability. Runs of homozygosity islands mapped candidate genes involved in the adaptation to local environment and immune response. Population genetic analyses using different approaches highlighted the hypothesis that this sheep possesses a defined genetic structure, especially if compared with other recognised breeds, despite the influence of other populations such as the Sicilian breeds. Overall, our findings represent a starting point for the possible official acknowledgement of this population, for the creation of a conservation plan, and thus for preserving this genomic heritage.HIGHLIGHTS Nera de Mela sheep can be considered as a reservoir of genetic diversity. The results indicated a clear genetic differentiation from other populations and moderate level of genetic variability. Our findings represent a starting point for the creation of conservation plans.

To ensure quality of education, a language framework should be the foundation on which second language curricula are developed. In 2010, the Council of Ministers of Education, Canada (CMEC), as suggested by Vandergrift (2006a, 2006b), recommended the use of the Common European Framework of Reference (CEFR) in the K-12 Canadian school context and presented several considerations for adaptation before it should be adopted and used. Although the CEFR is partially used across Canada, few of the CMEC's considerations have been met to date. Given this state of affairs, we suggest the made-in-Canada, Canadian Language Benchmarks and "les Niveaux de compétence linguistique canadiens" (CLB/NCLC) as an alternative. We argue that the CLB/NCLC, profoundly revised in 2012, best embrace the Canadian context and, using Vandergrift's criteria for a valid language framework, that CLB/NCLC are now superior to the CEFR in many aspects.

Bone defects are a global health concern; bone tissue engineering (BTE) is the most promising alternative to reduce patient morbidity and overcome the inherent drawbacks of autograft and allograft bone. Three-dimensional scaffolds are pivotal in this field due to their potential to provide structural support and mimic the natural bone microenvironment. Following an already published protocol, a 3D porous structure consisting of alginate and hydroxyapatite was prepared after a gelation step and a freezing-drying step. Despite the frequent use of alginate in tissue regeneration, the biological inertness of this polysaccharide hampers proper cell colonization and proliferation. Therefore, the purpose of this work was to enhance the biological properties by promoting the interaction and adhesion between cells and biomaterial with the use of Fibronectin. This extracellular matrix protein was physically adsorbed on the scaffold, and its presence was evaluated with environmental scanning electron microscopy (eSEM) and the Micro-Bicinchoninic Acid (μBCA) protein assay. The MG-63 cell line was used for both static and dynamic (i.e., in bioreactor) 3D cell culturing on the scaffolds. The use of the bioreactor allowed for a better exchange of nutrients and oxygen and a better removal of cell catabolites from the inner portion of the construct, mimicking the physiological environment. The functionalized scaffolds showed an improvement in cell proliferation and colonization compared to non-functionalized ones; the effect of the addition of Fibronectin was more evident in the dynamic culturing conditions, where the cells clearly adhered on the surface of functionalized scaffolds.

For children living in the urban slums of Nairobi (Kenya), primary health conditions are not guaranteed, and oral diseases add further concern at social and institutional levels beyond the general poverty conditions. This study aims at determining the factors that influence the oral health status of children living in Nairobi slums. A cross-sectional study on school-aged subjects was conducted in June 2022 in three urban slum areas of Nairobi through a pediatric dental screening. The PI (Plaque Index), CPITN (Community Periodontal Index of Treatment Needs), and dmft (decayed, missing, and filled teeth index—deciduous) were considered as primary outcomes of dental health. Multivariate statistical analysis, based on ordinal and zero-inflated negative binomial regression models, was conducted to identify determinants of the oral outcomes in a wide set of potential predictors. A sample of 359 children aged 2–17 was examined. The PI was significantly associated with age, the type of bite, and the use of a toothbrush. The CPITN is influenced by different types of malocclusions, abnormal frenulum, dental trauma, and fluorosis. Dietary habits were found to significantly impact the susceptibility to dental caries. Fluorosis and a dental visit in the last year were highlighted as risk and protective factors, respectively, against higher rates of caries. The oral health features of children living in Nairobi slums are differently affected by socio-demographic conditions, dietary habits, dental characteristics, and oral care practices.

In bone regeneration, combining natural polymer-based scaffolds with Bioactive Glasses (BGs) is an attractive strategy to improve the mechanical properties of the structure, as well as its bioactivity and regenerative potential. Methods: For this purpose, a well-studied alginate/hydroxyapatite (Alg/HAp) porous scaffold was enhanced with an experimental bioglass (BGMS10), characterized by a high crystallization temperature and containing therapeutic ions such as strontium and magnesium. This resulted in an improved biological response compared to 45S5 Bioglass®, the “gold” standard among BGs. Porous composite scaffolds were fabricated by freeze-drying technique and characterized by scanning electron microscopy and microanalysis, infrared spectroscopy, and microcomputed tomography. The mechanical properties and cytocompatibility of the new scaffold composition were also evaluated. The addition of bioglass to the Alg/HAp network resulted in a slightly lower porosity. However, despite the change in pore size, the MG-63 cells were able to better adhere and proliferate when cultured for one week on a BG scaffold compared to the control Alg/HAp scaffolds. Thus, our findings indicate that the combination of bioactive glass BGMS10 does not affect the structural and physicochemical properties of the Alg/HAp scaffold and confers bioactive properties to the structures, making the Alg/HAp-BGMS10 scaffold a promising candidate for future application in bone tissue regeneration.

The efficient planning and control of timber harvesting operations is crucial to growth productivity and reducing costs, and different systems or methods are applied to obtain elevated performance. In particular, cable yarding is a highly appreciated and very efficient wood extraction method in areas that are difficult to access with ground-based extraction machines. Combined logging systems are not diffuse and not often implemented. For this reason, the use and the application of innovative methods are limited. However, some combinations have recently been observed in forest operations. This study, conducted in a deciduous stand in Bulgaria, paid attention to the combination of a tractor-mounted tower yarder (Valentini V400) with a clambunk skidder (Timberjack 1010D), aiming to examine the viability and develop the operational efficiency of the two-stage extraction system and to define the time, log volume extracted per unit by the yarder and the clambunk, and the yarding and skidding costs. The researchers carried out a time-motion study and performed a regression analysis to identify those variables that are most likely to affect the duration of work elements and productivity. For cost analysis, the COST model was used. The mean productivity of the tower yarder was 10.34 m3/PMH and 8.11 m3/SMH, while for the clambunk skidder, the productivity was 6.23 m3/PMH and 4.93 m3/SMH. The net costs for the combined logging system were calculated as 120.87 €/PMH and 14.93 €/m3. This study adds new data about the correct use of both machines, supporting their application in beech forests.

Within psychology and the social sciences, Ordinary Least Squares (OLS) regression is one of the most popular techniques for data analysis. In order to ensure the inferences from the use of this method are appropriate, several assumptions must be satisfied, including the one of constant error variance (i.e. homoskedasticity). Most of the training received by social scientists with respect to homoskedasticity is limited to graphical displays for detection and data transformations as solution, giving little recourse if none of these two approaches work. Borrowing from the econometrics literature, this tutorial aims to present a clear description of what heteroskedasticity is, how to measure it through statistical tests designed for it and how to address it through the use of heteroskedastic-consistent standard errors and the wild bootstrap. A step-by-step solution to obtain these errors in SPSS is presented without the need to load additional macros or syntax. Emphasis is placed on the fact that non-constant error variance is a population-defined, model-dependent feature and different types of heteroskedasticity can arise depending on what one is willing to assume about the data.