181 research outputs found
Urban Principals’ Experiences and Perceptions of Teacher Effectiveness: An Analysis of Student Achievement, Hiring and Retention, and School Culture
In an effort to promote school improvement, principals have primarily focused on developing quality teachers as a method of enhancing the academic achievement of students. This article seeks to shed light on the experiences and per-ceptions of urban principals regarding teacher effectiveness. Specifically, this article focuses on principals’ outlooks on teachers’ in three areas: student achievement, hiring and retention, and school culture. Empirical data from this study was derived from a mixed-method cross sectional survey administered to urban school principals in Arizona and California. It was evident in this study that principals perceive teachers as either well qualified or very well qualified to educate urban students. These findings are incongruent with the greater literature on this topic which illustrates the quality of urban school teachers is in question in comparison to non-urban teachers. The implications of principals’ overwhelmingly positive outlook are discussed coupled with recommendations for future research
Context dependent substitution biases vary within the human genome
Background:
Models of sequence evolution typically assume that different nucleotide positions evolve independently. This assumption is widely appreciated to be an over-simplification. The best known violations involve biases due to adjacent nucleotides. There have also been suggestions that biases exist at larger scales, however this possibility has not been systematically explored.
Results:
To address this we have developed a method which identifies over- and under-represented substitution patterns and assesses their overall impact on the evolution of genome composition. Our method is designed to account for biases at smaller pattern sizes, removing their effects. We used this method to investigate context bias in the human lineage after the divergence from chimpanzee. We examined bias effects in substitution patterns between 2 and 5 bp long and found significant effects at all sizes. This included some individual three and four base pair patterns with relatively large biases. We also found that bias effects vary across the genome, differing between transposons and non-transposons, between different classes of transposons, and also near and far from genes.
Conclusions:
We found that nucleotides beyond the immediately adjacent one are responsible for substantial context effects, and that these biases vary across the genome
Self-distancing and Avoidance Mediate the Links Between Trait Mindfulness and Responses to Emotional Challenges
Objectives Mindfulness has been linked to better emotion regulation and more adaptive responses to stress across a number of studies, but the mechanisms underlying these links remain to be fully understood. The present study examines links between trait mindfulness (Five Facets of Mindfulness Questionnaire; FFMQ) and participants\u27 responses to common emotional challenges, focusing specifically on the roles of reduced avoidance and more self-distanced engagement as key potential mechanisms driving the adaptive benefits of trait mindfulness. Methods Adults (n = 305, age range: 40-72) from the Second Generation Study of the Harvard Study of Adult Development completed two laboratory-based challenges-public speaking combined with difficult math tasks (the Trier Social Stress Test) and writing about a memory of a difficult moment. State anxiety and sadness were assessed immediately before and after the two stressors. To capture different ways of engaging, measures of self-distancing, avoidance, and persistent worry were collected during the lab session. Results As predicted, individuals who scored higher on the FFMQ experienced less anxiety and persistent worry in response to the social stressors. The FFMQ was also linked to less anxiety and sadness when writing about a difficult moment. The links between mindfulness and negative emotions after the writing task were independently mediated by self-distanced engagement and lower avoidance. Conclusions Affective benefits of trait mindfulness under stress are associated with both the degree and the nature of emotional engagement. Specifically, reduced avoidance and self-distanced engagement may facilitate reflection on negative experiences that is less affectively aversive
Coherence Between Feelings and Heart Rate: Links to Early Adversity and Responses to Stress
Past research suggests that higher coherence between feelings and physiology under stress may confer regulatory advantages. Research and theory also suggest that higher resting vagal tone (rVT) may promote more adaptive responses to stress. The present study examines the roles of response system coherence (RSC; defined as the within-individual covariation between feelings and heart rate over time) and rVT in mediating the links between childhood adversity and later-life responses to acute stressors. Using data from 279 adults from the Second Generation Study of the Harvard Study of Adult Development who completed stressful public speaking and mental arithmetic tasks, we find that individuals who report more childhood adversity have lower RSC, but not lower rVT. We further find that lower RSC mediates the association between adversity and slower cardiovascular recovery. Higher rVT in the present study is linked to less intense cardiovascular reactivity to stress, but not to quicker recovery or to the subjective experience of negative affect after the stressful tasks. Additional analyses indicate links between RSC and mindfulness and replicate previous findings connecting RSC to emotion regulation and well-being outcomes. Taken together, these findings are consistent with the idea that uncoupling between physiological and emotional streams of affective experiences may be one of the mechanisms connecting early adversity to later-life affective responses. These findings also provide evidence that RSC and rVT are associated with distinct aspects of self-regulation under stress. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s42761-020-00027-5
Systematic review of global functioning and quality of life in people with psychotic disorders
Aims People with psychotic disorders face impairments in their global functioning and their quality of life (QoL). The relationship between the two outcomes has not been systematically investigated. Through a systematic review, we aim to explore the presence and extent of associations between global functioning and QoL and establish whether associations depend on the instruments employed.Methods In May 2016, ten electronic databases were searched using a two-phase process to identify articles in which associations between global functioning and QoL were assessed. Basic descriptive data and correlation coefficients between global functioning and QoL instruments were extracted, with the strength of the correlation assessed according to the specifications of Cohen 1988. Results were reported with reference to the Meta-analysis of Observational Studies in Epidemiology guidelines and PRISMA standards. A narrative synthesis was performed due to heterogeneity in methodological approaches.Results Of an initial 15 183 non-duplicate articles identified, 756 were deemed potentially relevant, with 40 studies encompassing 42 articles included. Fourteen instruments for measuring global functioning and 22 instruments for measuring QoL were used. Twenty-nine articles reported linear associations while 19 assessed QoL predictors. Correlations between overall scores varied in strength, primarily dependent on the QoL instrument employed, and whether QoL was objectively or subjectively assessed. Correlations observed for objective QoL measures were consistently larger than those observed for subjective measures, as were correlations for an interviewer than self-assessed QoL. When correlations were assessed by domains of QoL, the highest correlations were found for social domains of QoL, for which most correlations were moderate or higher. Global functioning consistently predicted overall QoL as did depressive and negative symptoms.Conclusions This review is the first to explore the extent of associations between global functioning and QoL in people with psychotic disorders. We consistently found a positive association between global functioning and QoL. The strength of the association was dependent on the QoL instrument employed. QoL domains strongly associated with global functioning were highlighted. The review illustrates the extensive array of instruments used for the assessment of QoL and to a lesser extent global functioning in people with psychotic disorders and provides a framework to understand the different findings reported in the literature. The findings can also inform the future choice of instruments by researchers and/or clinicians. The observed associations reassure that interventions for improving global functioning will have a positive impact on the QoL of people living with a psychotic disorder
Growth Endocrine Axis and Bovine Chromosome 5: Association of SNP Genotypes and Reproductive Phenotypes in an Angus, Brahman and Romosinuano Diallele
The growth endocrine axis influences reproduction. A QTL associated with enhanced ovulation exists on chromosome 5 in cattle and there are 6 genes underlying this region involved in the mechanisms of GH action. Resequencing exons, 5’ and 3’ untranslated regions and conserved non-coding regions of these genes in a multibreed resource population revealed 75 SNP usable for genotype to phenotype association studies. In the current study, phenotypes included age at first calving, calving interval, days to calving, and pregnancy rate. Data were collected from developing heifers (n = 650) of a diallele composed of Angus, Brahman, and Romosinuano breeds. A SNP in the promoter of the signal transducer and activator of transcription (STAT)2 gene, which is a second messenger of GH, had minor allele frequency \u3e 10% across the three breeds. This SNP did not deviate from Hardy- Weinberg equilibrium (X2 = 1.00, P \u3e 0.31), so deemed useful for genotype to phenotype association analyses. Since the remaining SNP appeared to predict breed, they were used to correct for population stratification using STRUCTURE, which revealed three distinctive ancestral clusters. No significant association was detected between the STAT2 genotype and reproductive traits in mixed effects analyses using genotype as a fixed term, sire as a random term, and coefficient of ancestry as a covariate; however, the interaction of SNP genotype and ancestral cluster was associated with the traits days to calving (P \u3c 0.05) and calving interval (P \u3c 0.10). Interaction plots revealed a higher estimated effect of heterozygous genotype in cluster 1 (inferred primarily from Brahman) and lower estimates in clusters 2 and 3 (inferred primarily from Bos taurus). The heterozygous genotype extended these trait levels ~100 d. A SNP in the promoter of the STAT2 gene was associated with fertility trait levels in admixed cows of the breeds Angus, Brahman, and Romosinuano. The effect appeared to be a non-additive genetic relationship as heterozygous genotype extended levels of traits indicative of postpartum rebreeding
The Earlier the Better: Structural Analysis and Separation of Lanthanides with Pyrroloquinoline Quinone
Lanthanides (Ln) are critical raw materials, however, their mining and purification have a considerable negative environmental impact and sustainable recycling and separation strategies for these elements are needed. In this study, the precipitation and solubility behavior of Ln complexes with pyrroloquinoline quinone (PQQ), the cofactor of recently discovered lanthanide (Ln) dependent methanol dehydrogenase (MDH) enzymes, is presented. In this context, the molecular structure of a biorelevant europium PQQ complex was for the first time elucidated outside a protein environment. The complex crystallizes as an inversion symmetric dimer, Eu2PQQ2, with binding of Eu in the biologically relevant pocket of PQQ. LnPQQ and Ln1Ln2PQQ complexes were characterized by using inductively coupled plasma mass spectrometry (ICP‐MS), infrared (IR) spectroscopy, 151Eu‐Mössbauer spectroscopy, X‐ray total scattering, and extended X‐ray absorption fine structure (EXAFS). It is shown that a natural enzymatic cofactor is capable to achieve separation by precipitation of the notoriously similar, and thus difficult to separate, lanthanides to some extent
Efecto de tratamiento térmico en aleaciones feal1% at li expuestas a pruebas de oxidación en diferentes temperaturas
La adición de Li en aleaciones intermetalicas base Fe3Al ayuda en la mejora de propiedades mecánicas y resistencia a la corrosión. Las aleaciones se producen con técnicas convencionales de vaciado usando crisoles de SiC y se someten a un tratamiento térmico de 400ºC por 144h. Se realizaron pruebas de oxidación de alta temperatura en termobalanza con atmósfera estática a temperaturas de 650, 800 y 900 ºC las cuales indicaron una diferencia en la cinética de oxidación entre las muestras con tratamiento térmico y sin el. Por análisis de Microscopía electrónica de barrido se pudo ver que la capa de oxidación es más uniforme cuando se tiene tratamiento térmico
Efecto de tratamiento térmico en aleaciones feal1% at li expuestas a pruebas de oxidación en diferentes temperaturas
La adición de Li en aleaciones intermetalicas base Fe3Al ayuda en la mejora de propiedades mecánicas y resistencia a la corrosión. Las aleaciones se producen con técnicas convencionales de vaciado usando crisoles de SiC y se someten a un tratamiento térmico de 400ºC por 144h. Se realizaron pruebas de oxidación de alta temperatura en termobalanza con atmósfera estática a temperaturas de 650, 800 y 900 ºC las cuales indicaron una diferencia en la cinética de oxidación entre las muestras con tratamiento térmico y sin el. Por análisis de Microscopía electrónica de barrido se pudo ver que la capa de oxidación es más uniforme cuando se tiene tratamiento térmico
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