Development of a photometric primary transfer standard for reflectance goniospectrophotometry

Currently, photometric standards are calibrated only at CIE-recommended geometries. A need exists for calibrating at many combinations of illumination and viewing angles. The common practice is to assume BaSO4 is lambertian although its non-Iambertian behavior is well-known. Accordingly, a study was undertaken to develop a standard for this type of metrology. Two diffuse materials, BaSO4 and PTFE, were characterized goniospectrophotometrically. PTFE, when pressed to a density of 1.55g/cc against a lapping film, exhibited properties lending itself as a transfer standard. Bidirectional absolute spectral reflectance factors at 60 combinations of illumination and viewing angles in a single plane were measured. Neither material was found to be lambertian and both polarized the reflected radiation. The PTFE standard had greater spectral non-selectivity and could be prepared repeatably

Direct iminization of PEEK

Semi-crystalline poly(ether ketone)s are important high-temperature engineering thermoplastics, but are difficult to characterize at the molecular level because of their insolubility in conventional organic solvents. Here we report that polymers of this type, including PEEK, react cleanly at high temperatures with low-volatility aralkyl amines to afford stable, noncrystalline poly(ether-imine)s, which are readily soluble in solvents such as chloroform, THF and DMF and so characterizable by conventional size-exclusion chromatography

Characterizing and Predicting Canadian Adolescents’ Internalizing Symptoms In The First Year Of The COVID-19 Pandemic

To date, most longitudinal studies of adolescents’ internalizing symptoms during the COVID-19 pandemic include few time points, limiting knowledge about the long-term course of adolescents’ mental health during the pandemic. Moreover, examining intraindividual variability in symptoms, which may have important implications for adolescents’ adjustment beyond mean or “typical” symptoms, requires multiple time points. We examined the course of internalizing symptoms in 271 Ontario adolescents (mean n = 193 across time points) during the first year of the pandemic (March 2020–April 2021) via mixed-effect location scale models, drawing upon established internalizing symptom risk factors as predictors of mean trends and intraindividual variability. Adolescents’ internalizing symptoms were relatively stable and generally low over the first year of the pandemic, with severity peaking in February and April 2021. Girls showed more symptoms on average and greater intraindividual variability in symptoms. Parents’ depressive symptoms predicted intraindividual variability in adolescents’ anxious and depressive symptoms. Adolescents’ symptoms were stable and generally below clinical cutoffs. However, female adolescents and those whose parents experienced more depressive symptoms were most vulnerable to the stress of the pandemic. Implications for intervention and prevention efforts are discussed

Children\u27s neural reactivity to maternal praise and criticism: Associations with early depressive symptoms and maternal depression

Caregiving experiences are implicated in children\u27s depression risk; however, children\u27s neural reactivity to positive and negative feedback from mothers, a potential mediator of depression risk, is poorly understood. In a sample of 81 children

Developing Instruments to Measure Montessori Instructional Practices

Researchers who study any intervention must rule out potential alternative explanations for their results by establishing that the program being investigated is implemented with fidelity. Various instructional practices are attributed to the Montessori Method because the term is not legally protected, meaning any school can say it is Montessori regardless of the degree to which it adheres to practices generally understood to represent Montessori education. Researchers have used a variety of tools to measure the fidelity of Montessori environments they study, but most of these tools lack an extensive psychometric foundation or are labor intensive, requiring in-person observation. The purpose of this study was to examine the psychometric properties of instruments that were developed to measure Montessori implementation through Early Childhood (EC) and Elementary (EL) teachers’ reported instructional practices. Findings supported three hypothesized dimensions of Montessori implementation (structure, curriculum, and freedom), which worked fairly well in describing practices. While the properties of these instruments are promising and provide preliminary supporting evidence, results of this analysis suggest further refinement of the items in these instruments is necessary with larger and more diverse samples. While we do not suggest that these are finalized tools, we believe they provide a valuable starting point that is a vast improvement over the requirement of investigators to develop their own instruments as part of each Montessori study they design. The authors hope other researchers will incorporate these instruments into their studies to help build a robust body of evidence supporting their use

Efeito de Beauveria bassiana sobre Cerotoma arcuata (Olivier, 1791) (Coleoptera: chrysomelidae) após exposição de esporos do fungo a tubérculos de taiuiá (Ceratosanthes hilariana).

Isolados do fungo entomógeno Beauveria bassiana (Deuteromycetes, Moniliales), provenientes de várias regiões do Brasil, têm demonstrado, através de bioensaios, alta patogenicidade a adultos de Cerotoma arcuata (0livier, 1791), importante praga de feijão (Phaseolus vulgaris) e caupi ( Vigna unguiculata)

Designing a Logic Model to Inform Montessori Research

Montessori education has a long history, but its recent growth in American public schools has led to increased interest in research efforts, particularly in exploring the potential of the Montessori experience to moderate the effects of poverty and in gathering data to evaluate public investment in Montessori schools. To assist research efforts, this paper introduces a comprehensive visual model, or logic model, that depicts the core components, underlying assumptions, and intended outcomes of the Montessori approach. Logic modeling, which results in a visual representation depicting the connections among a program’s inputs, primary activities, and outcomes, is often used in program planning and research to provide a common framework from which to work. Developed over a 3-year period by a collaborative group of experienced Montessori researchers and practitioners, the Logic Model for Montessori Education presented in this paper is a valuable tool for researchers with the potential to lay a foundation across disciplines for future research that is both rigorous and systematic in its measurement of Montessori processes and outcomes

Dissemination of Metarhizium anisopliae of low and high virulence by mating behavior in Aedes aegypti

<p>Abstract</p> <p>Background</p> <p>Dengue is a viral disease transmitted by <it>Aedes </it>mosquitoes. It is a threat for public health worldwide and its primary vector <it>Aedes aegypti </it>is becoming resistant to chemical insecticides. These factors have encouraged studies to evaluate entomopathogenic fungi against the vector. Here we evaluated mortality, infection, insemination and fecundity rates in <it>A. aegypti </it>females after infection by autodissemination with two Mexican strains of <it>Metarhizium anisopliae</it>.</p> <p>Methods</p> <p>Two <it>M. anisopliae </it>strains were tested: The Ma-CBG-1 least virulent (lv), and the Ma-CBG-2 highly virulent (hv) strain. The lv was tested as non mosquito-passed (NMP), and mosquito-passed (MP), while the hv was examined only as MP version, therefore including the control four treatments were used. In the first bioassay virulence of fungal strains towards female mosquitoes was determined by indirect exposure for 48 hours to conidia-impregnated paper. In the second bioassay autodissemination of fungal conidia from fungus-contaminated males to females was evaluated. Daily mortality allowed computation of survival curves and calculation of the LT₅₀by the Kaplan-Meier model. All combinations of fungal sporulation and mating insemination across the four treatments were analyzed by χ². The mean fecundity was analyzed by ANOVA and means contrasted with the Ryan test.</p> <p>Results</p> <p>Indirect exposure to conidia allowed a faster rate of mortality, but exposure to a fungal-contaminated male was also an effective method of infecting female mosquitoes. All females confined with the hv strain-contaminated male died in fifteen days with a LT₅₀of 7.57 (± 0.45) where the control was 24.82 (± 0.92). For the lv strain, it was possible to increase fungal virulence by passing the strain through mosquitoes. 85% of females exposed to hv-contaminated males became infected and of them just 10% were inseminated; control insemination was 46%. The hv strain reduced fecundity by up to 99%, and the lv strain caused a 40% reduction in fecundity.</p> <p>Conclusions</p> <p>The hv isolate infringed a high mortality, allowed a low rate of insemination, and reduced fecundity to nearly zero in females confined with a fungus-contaminated male. This pathogenic impact exerted through sexual transmission makes the hv strain of <it>M. anisopliae </it>worthy of further research.</p