264 research outputs found

    Motivational and personality variables distinguish academic underachievers from high achievers, low achievers, and overachievers

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    Previous studies have associated several variables concerning motivation and other domains with underachievement, i. e. a student's academic achievement falling short of what their cognitive abilities, as the best predictor of academic performance, would indicate. The present study extends these findings using a more rigorous approach in defining underachievers and suitable control groups. Using discriminant analysis, underachievers identified in a German twin family study were compared not only to achievers with comparable IQ scores, but also with students of lower aptitude, but comparably low grades, as well as overachieving students. Results confirm previous findings that compared to successful students, underachievers report lower levels of motivation and parental support; beyond this comparison, underachievers also differed from other low achievers, mostly in terms of their personality. In total, 40% of the variance between the groups were explained. Additionally, the data shed doubt on the common assumption that underachievers are an unusually heterogenous group of students

    Meetgegevens strijkbuigen staal en aluminium

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    Dystrophin Distribution and Expression in Human and Experimental Temporal Lobe Epilepsy

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    Objective: Dystrophin is part of a protein complex that connects the cytoskeleton to the extracellular matrix. In addition to its role in muscle tissue, it functions as an anchoring protein within the central nervous system such as in hippocampus and cerebellum. Its presence in the latter regions is illustrated by the cognitive problems seen in Duchenne Muscular Dystrophy (DMD). Since epilepsy is also supposed to constitute a comorbidity of DMD, it is hypothesized that dystrophin plays a role in neuronal excitability. Here, we aimed to study brain dystrophin distribution and expression in both, human and experimental temporal lobe epilepsy (TLE). Method: Regional and cellular dystrophin distribution was evaluated in both human and rat hippocampi and in rat cerebellar tissue by immunofluorescent colocalization with neuronal (NeuN and calbindin) and glial (GFAP) markers. In addition, hippocampal dystrophin levels were estimated by Western blot analysis in biopsies from TLE patients, post-mortem controls, amygdala kindled (AK)-, and control rats. Results: Dystrophin was expressed in all hippocampal pyramidal subfields and in the molecular-, Purkinje-, and granular cell layer of the cerebellum. In these regions it colocalized with GFAP, suggesting expression in astrocytes such as Bergmann glia (BG) and velate protoplasmic astrocytes. In rat hippocampus and cerebellum there were neither differences in dystrophin positive cell types, nor in the regional dystrophin distribution between AK and control animals. Quantitatively, hippocampal full-length dystrophin (Dp427) levels were about 60% higher in human TLE patients than in post-mortem controls (p < 0.05), whereas the level of the shorter Dp71 isoform did not differ. In contrast, AK animals showed similar dystrophin levels as controls. Conclusion: Dystrophin is ubiquitously expressed by astrocytes in the human and rat hippocampus and in the rat cerebellum. Hippocampal full-length dystrophin (Dp427) levels are upregulated in human TLE, but not in AK rats, possibly indicating a compensatory mechanism in the chronic epileptic human brain

    Meetgegevens vrijbuigen staal en aluminium

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    Het Nieuwe Telen: Gerbera: Efficiëntie, economie en energie - Teeltseizoen 2011-2012

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    De centrale vraag van het derde jaar Het Nieuwe Telen (HNT) was: Wat is een economisch rendabel systeem waarmee de voordelen van Het Nieuwe Telen wel zichtbaar worden? De Gerbera telers zijn er van overtuigd dat een energie doelstelling alleen niet voldoende is. Er moet een energie en productie doelstelling voor de periode week 40 tot en met week 10 worden gesteld, zodat door een gestegen productie en beheerste energie input de energie-efficiëntie verder wordt verhoogd

    Metformin kills and radiosensitizes cancer cells and preferentially kills cancer stem cells

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    The anti-cancer effects of metformin, the most widely used drug for type 2 diabetes, alone or in combination with ionizing radiation were studied with MCF-7 human breast cancer cells and FSaII mouse fibrosarcoma cells. Clinically achievable concentrations of metformin caused significant clonogenic death in cancer cells. Importantly, metformin was preferentially cytotoxic to cancer stem cells relative to non-cancer stem cells. Metformin increased the radiosensitivity of cancer cells in vitro, and significantly enhanced the radiation-induced growth delay of FSaII tumors (s.c.) in the legs of C3H mice. Both metformin and ionizing radiation activated AMPK leading to inactivation of mTOR and suppression of its downstream effectors such as S6K1 and 4EBP1, a crucial signaling pathway for proliferation and survival of cancer cells, in vitro as well as in the in vivo tumors. Conclusion: Metformin kills and radiosensitizes cancer cells and eradicates radioresistant cancer stem cells by activating AMPK and suppressing mTOR

    Numerical and experimental investigation of a lightweight bonnet for pedestrian safety

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    A topic of great consideration in current vehicle development in Europe is pedestrian protection. The enforcement of a new regulation trying to decrease the injuries to head, pelvis, and leg of pedestrian impacted by cars, is imposing great changes in vehicles' front design. In the present work a design solution for the bonnet, which is the main body part interacting with the human head during a car to pedestrian collision, is proposed. This solution meets the stiffness and safety targets, takes into account the manufacturing and recyclability requirements and gives a relevant contribution to vehicle lightweight. Thus this proposed solution puts in evidence that safety and lightweight are not incompatible targets. The amount of potential injury to the pedestrian head is evaluated, as prescribed by the standard test procedures, by means of a headform launched on the bonnet. However, the standard approach based on the head injury criterion (HIC) value only is reported to be largely unsatisfactory: therefore, a new experimental methodology for the measurement of the translational and the rotational accelerations has been developed, and the experimental results are reported. This would be a starting point for the evolution of currently adopted injury criteria to increase the safety of the vulnerable road user
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