1,542 research outputs found

    Perceptions of Classroom Working Alliance and Student Performance

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    Positive teacher-student relationship has been established as an important contributor to students' social, behavioral, and academic adjustment. Nevertheless, current research has not employed relationship measures that examine both teachers' and students' perceptions. Furthermore, the measures currently being used lack breadth in the definition of the teacher-student relationship. Using the construct of "working alliance" from counseling psychology, this study investigated teachers' (n=14) and elementary school students' (n=53) perceptions of their working alliance and explored how this construct relates to student performance. Teachers' and students' ratings on subscales of the Classroom Working Alliance Inventory (CWAI) were found to be significantly related to one another. In addition, regression analyses demonstrated that both teachers' and students' ratings of working alliance contributed significantly to ratings on the Student Performance Questionnaire (SPQ).Un rapport positif entre l'enseignant et l'élève s'est avéré être un facteur important qui contribue à l'adaptation sociale, comportementale et académique des élèves. Néanmoins, la recherche actuelle n'a pas employé de mesures des rapports qui examinent à la fois les perceptions des enseignants et celles des élèves. De plus, les mesures actuelles manquent d'envergure quant à leur définition du rapport enseignant-élève. Empruntant de la psychologie thérapeutique la construction de l'alliance de travail, nous avons étudié les perceptions qu'ont les enseignants (n=14) et les élèves de l'élémentaire (n=53) de leur alliance de travail et avons examiné dans quelle mesure cette construction joue un rôle dans le rendement des élèves. Nous avons trouvé une relation significative entre les cotes des enseignants et celles des élèves aux sous-échelles de l'inventaire de l'alliance de travail en salle de classe (Classroom Working Alliance Inventory). De plus, les analyses de régression ont démontré que ces cotes, tant celles des enseignants que celles des élèves, ont contribué de façon significative aux cotes du questionnaire sur le rendement des élèves

    Euler-Bessel and Euler-Fourier Transforms

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    We consider a topological integral transform of Bessel (concentric isospectral sets) type and Fourier (hyperplane isospectral sets) type, using the Euler characteristic as a measure. These transforms convert constructible \zed-valued functions to continuous \real-valued functions over a vector space. Core contributions include: the definition of the topological Bessel transform; a relationship in terms of the logarithmic blowup of the topological Fourier transform; and a novel Morse index formula for the transforms. We then apply the theory to problems of target reconstruction from enumerative sensor data, including localization and shape discrimination. This last application utilizes an extension of spatially variant apodization (SVA) to mitigate sidelobe phenomena

    Nanoengineered Astronomical Optics

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    We describe a technology for the fabrication of inexpensive and versatile mirrors through the use of a new type of nanoengineered optical material composed by the spreading of a self-assembling reflective colloidal film spread at the surface of a liquid. These new reflecting liquids offer interesting possibilities for astronomical instrumentation. For example, they can replace mercury in conventional rotating liquid mirrors. The main advantages offered include extremely low cost and, by coating a viscous liquid, the possibility of tilting the mirror by a few tens of degrees. We also have coated ferromagnetic liquids with these reflecting films. The resulting surfaces can be shaped by the application of a magnetic field, yielding reflecting surfaces that can have complicated shapes that can rapidly shift with time. These inexpensive and versatile optical elements could have numerous scientific and technological applications. Among possible astronomical applications, they could be used to make large inexpensive adaptive mirrors exhibiting strokes ranging from nanometers to several millimeters.Comment: Submitted to Astrophysical Journal Letters. 18 pages, 4 figure

    The epidemiology of fighting in group-housed laboratory mice

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    Injurious home-cage aggression (fighting) in mice affects both animal welfare and scientific validity. It is arguably the most common potentially preventable morbidity in mouse facilities. Existing literature on mouse aggression almost exclusively examines territorial aggression induced by introducing a stimulus mouse into the home-cage of a singly housed mouse (i.e. the resident/intruder test). However, fighting occurring in mice living together in long-term groups under standard laboratory housing conditions has barely been studied. We performed a point-prevalence epidemiological survey of fighting at a research institution with an approximate 60,000 cage census. A subset of cages was sampled over the course of a year and factors potentially influencing home-cage fighting were recorded. Fighting was almost exclusively seen in group-housed male mice. Approximately 14% of group-housed male cages were observed with fighting animals in brief behavioral observations, but only 14% of those cages with fighting had skin injuries observable from cage-side. Thus simple cage-side checks may be missing the majority of fighting mice. Housing system (the combination of cage ventilation and bedding type), genetic background, time of year, cage location on the rack, and rack orientation in the room were significant risk factors predicting fighting. Of these predictors, only bedding type is easily manipulated to mitigate fighting. Cage ventilation and rack orientation often cannot be changed in modern vivaria, as they are baked in by cookie-cutter architectural approaches to facility design. This study emphasizes the need to invest in assessing the welfare costs of new housing and husbandry systems before implementing them

    Could rebel child soldiers prolong civil wars?

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    While we know why rebels may recruit children for their cause, our understanding of the consequences of child soldiering by non-state armed groups remains limited. The following research contributes to addressing this by examining how rebels? child recruitment practice affects the duration of internal armed conflicts. We advance the argument that child soldiering increases the strength of rebel organizations vis-�-vis the government. This, in turn, lowers the capability asymmetry between these nonstate actors and the incumbent, allowing the former to sustain in dispute. Ultimately, the duration of armed conflicts is likely to be prolonged. We analyze this relationship with quantitative data on child soldier recruitment by rebel groups in the post-1989 period. The results confirm our main hypothesis: disputes are substantially longer when rebels recruit children. This work has important implications for the study of armed conflicts, conflict duration, and our understanding of child soldiering

    Indications of decreasing human PTS concentrations in North West Russia

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    The Russian Arctic covers an enormous landmass with diverse environments. It inhabits more than 20 different ethnic groups, all of them with various living conditions and food traditions. Indigenous populations with a traditional way of living are exposed to a large number of anthropogenic pollutants, such as persistent organic pollutants (POPs) and toxic metals, mainly through the diet. Human monitoring of persistent organic pollutants (POPs) and heavy metals in the Russian Arctic has only been performed on irregular intervals over the past 15 years, thus, there is still a lack of baseline data from many ethnic groups and geographical regions. The aim of the current study was to investigate concentrations of POPs and toxic metals in three groups of indigenous people from the Russian Arctic. Plasma concentrations of POPs were measured in one of the locations (Nelmin-Nos) in 2001–2003 which gave the unique opportunity to compare concentrations over time in a small Russian arctic community. During 2009 and early 2010, 209 blood samples were collected from three different study sites in North West Russia; Nelmin-Nos, Izhma and Usinsk. The three study sites are geographically separated and the inhabitants are expected to have different dietary habits and living conditions. All blood samples were analyzed for POPs and toxic metals. PCB 153 was present in highest concentrations of the 18 PCBs analyzed. p,p′-DDE and HCB were the two most dominating OC pesticides. Males had higher concentrations of PCB 138, 153 and 180 than women and age was a significant predictor of PCB 153, 180, HCB and p,p′-DDD. Males from Izhma had significantly higher concentrations of HCB than males from the other study sites and women from Usinsk had higher concentrations of p,p′-DDE. Parity was a significant predictor of p,p′-DDE. Hg and Pb concentrations increased with increasing age and males had significantly higher concentrations of Pb than women. The study group from Izhma had significantly higher concentrations of Cd when controlling for age and gender and the study group from Usinsk had higher concentrations of Se than the others. Compared to the results from Nelmin-Nos in 2001–2003, a clear decrease in p,p′-DDE concentrations for both women and men was observed. The current study indicates a significant reduction of several PTSs in human blood samples from North West Russia over the past 10 years

    Acute Infections and Environmental Exposure to Organochlorines in Inuit Infants from Nunavik

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    The Inuit population of Nunavik (Canada) is exposed to immunotoxic organochlorines (OCs) mainly through the consumption of fish and marine mammal fat. We investigated the effect of perinatal exposure to polychlorinated biphenyls (PCBs) and dichlorodiphenyldichloroethylene (DDE) on the incidence of acute infections in Inuit infants. We reviewed the medical charts of a cohort of 199 Inuit infants during the first 12 months of life and evaluated the incidence rates of upper and lower respiratory tract infections (URTI and LRTIs, respectively), otitis media, and gastrointestinal (GI) infections. Maternal plasma during delivery and infant plasma at 7 months of age were sampled and assayed for PCBs and DDE. Compared to rates for infants in the first quartile of exposure to PCBs (least exposed), adjusted rate ratios for infants in higher quartiles ranged between 1.09 and 1.32 for URTIs, 0.99 and 1.39 for otitis, 1.52 and 1.89 for GI infections, and 1.16 and 1.68 for LRTIs during the first 6 months of follow-up. For all infections combined, the rate ratios ranged from 1.17 to 1.27. The effect size was similar for DDE exposure but was lower for the full 12-month follow-up. Globally, most rate ratios were > 1.0, but few were statistically significant (p < 0.05). No association was found when postnatal exposure was considered. These results show a possible association between prenatal exposure to OCs and acute infections early in life in this Inuit population

    A cardinal role for cathepsin D in co-ordinating the host-mediated apoptosis of macrophages and killing of pneumococci

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    The bactericidal function of macrophages against pneumococci is enhanced by their apoptotic demise, which is controlled by the anti-apoptotic protein Mcl-1. Here, we show that lysosomal membrane permeabilization (LMP) and cytosolic translocation of activated cathepsin D occur prior to activation of a mitochondrial pathway of macrophage apoptosis. Pharmacological inhibition or knockout of cathepsin D during pneumococcal infection blocked macrophage apoptosis. As a result of cathepsin D activation, Mcl-1 interacted with its ubiquitin ligase Mule and expression declined. Inhibition of cathepsin D had no effect on early bacterial killing but inhibited the late phase of apoptosis-associated killing of pneumococci in vitro. Mice bearing a cathepsin D-/- hematopoietic system demonstrated reduced macrophage apoptosis in vivo, with decreased clearance of pneumococci and enhanced recruitment of neutrophils to control pulmonary infection. These findings establish an unexpected role for a cathepsin D-mediated lysosomal pathway of apoptosis in pulmonary host defense and underscore the importance of apoptosis-associated microbial killing to macrophage function

    The impact of child soldiers on rebel groups’ fighting capacities

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    Several rebel groups actively recruit children to serve among their ranks. While this constitutes one of the most egregious violations of children’s rights, it remains unclear what impact recruited children have on the fighting capacities of these armed groups. The existing research suggests that, on the one hand, armed groups drafting children might also be militarily effective, since it is cheaper to provide for children, they are more obedient and aggressive than adults, and easily manipulable. On the other hand, children may negatively affect rebel groups’ fighting capacities as they are less proficient combatants than adults and often difficult to control. We add to this debate by systematically analyzing the quantitative evidence on the impact of child soldiers on rebel groups’ fighting capacities. Based on the analysis of newly compiled data on child recruitment by rebel groups between 1989 and 2010, our analyses show that children may actually increase rebel groups’ fighting capacities. That said, rebels’ ability to procure arms and the access to resources seem to be more important determinants of fighting capacity. The authors discuss these findings in light of policy implications and avenues for future research. </jats:p
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