145 research outputs found

    Repensando efeitos colaterais de responsabilização/accountability na educação. Resultados de um estudo multi-métodos em quatro sistemas escolares alemães

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    Based on a research project comprising data from an interview study and a survey with teachers and school principals in four German federal states (Bundesländer), this paper questions the claim that the side effects of accountability in education are bound to high-stakes contexts, and also provides evidence of side effects occurring in no- and low-stakes contexts. The findings suggest that side effects cannot be fully explained by certain implementation features of accountability regimes (e.g. high stakes), but should rather be understood as a result of implementation features as well as systematic effects of accountability in education.Basado en un proyecto de investigación que comprende datos de entrevistas y encuestas con profesores y directores de escuelas en cuatro Estados federados (Bundesländer), este trabajo cuestiona la afirmación de que los efectos secundarios de rendición de cuentas en educación están limitados a contextos de gran repercusión (high-stakes) y también proporciona evidencias de efectos secundarios que ocurren en contextos de baja o sin repercussion (low-stakes). Los resultados sugieren que los efectos secundarios no pueden explicarse completamente por ciertas características de la aplicación de los regímenes de rendición de cuentas por ejemplo de gran repercusión, pero debe entenderse más bien como ambos: como resultado de características de implementación y como efectos sistemáticos de rendición de cuentas en la educación. Baseado em um projeto de pesquisa que abrange dados de entrevistas e questionários com professores e diretores de escolas em quatro unidades da federação alemã (Bundesländer), este texto questiona a alegação de que os efeitos colaterais de responsabilização/accountability na educação estão vinculados aos contextos onde há sançoes (high-stakes) e também traz evidências dos efeitos que ocorrem em contextos com menores ou sem consequencias (low-stakes). Os resultados sugerem que efeitos colaterais não podem ser totalmente explicados por certas características de implementação de regimes de responsabilidade, por exemplo, high-stakes, mas antes devem ser entendidos como ambos: como resultado de características de implementação e como efeitos sistemáticos de responsabilização na educação

    Atomically resolved TEM imaging of covalently functionalised graphene

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    Covalent functionalisation can be a powerful lever to tune the properties and processability of graphene. After overcoming the low chemical reactivity of graphene, covalent functionalisation led to the generation of new hybrid materials, applicable in a broad variation of fields. Although the process of functionalising graphene is nowadays firmly established, fundamental aspects of the produced hybrid materials remain to be clarified. Especially the atomically resolved imaging is only scarcely explored. Here we show aberration corrected in situ high resolution TEM imaging of dodecyl functionalised monolayer graphene at atomic resolution after an effective mechanical filtering approach. The mechanical filtering allows to separate adsorbed contamination from the covalently bound functional molecules and thus opens the possibility for the observation of this hybrid material. The obtained data is validated by DFT calculations and by a novel image simulation approach based on molecular dynamics (MD) simulations at room temperature

    Dynamics of end to end loop formation for an isolated chain in viscoelastic fluid

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    We theoretically investigate the looping dynamics of a linear polymer immersed in a viscoelastic fluid. The dynamics of the chain is governed by a Rouse model with a fractional memory kernel recently proposed by Weber et al. (S. C. Weber, J. A. Theriot, and A. J. Spakowitz, Phys. Rev. E 82, 011913 (2010)). Using the Wilemski-Fixman (G. Wilemski and M. Fixman, J. Chem. Phys. 60, 866 (1974)) formalism we calculate the looping time for a chain in a viscoelastic fluid where the mean square displacement of the center of mass of the chain scales as t^(1/2). We observe that the looping time is faster for the chain in viscoelastic fluid than for a Rouse chain in Newtonian fluid up to a chain length and above this chain length the trend is reversed. Also no scaling of the looping time with the length of the chain seems to exist for the chain in viscoelastic fluid

    Wnt4 and LAP2alpha as pacemakers of Thymic Epithelial Senescence

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    Age-associated thymic involution has considerable physiological impact by inhibiting de novo T-cell selection. This impaired T-cell production leads to weakened immune responses. Yet the molecular mechanisms of thymic stromal adipose involution are not clear. Age-related alterations also occur in the murine thymus providing an excellent model system. In the present work structural and molecular changes of the murine thymic stroma were investigated during aging. We show that thymic epithelial senescence correlates with significant destruction of epithelial network followed by adipose involution. We also show in purified thymic epithelial cells the age-related down-regulation of Wnt4 (and subsequently FoxN1), and the prominent increase in LAP2α expression. These senescence-related changes of gene expression are strikingly similar to those observed during mesenchymal to pre-adipocyte differentiation of fibroblast cells suggesting similar molecular background in epithelial cells. For molecular level proof-of-principle stable LAP2α and Wnt4-over-expressing thymic epithelial cell lines were established. LAP2α over-expression provoked a surge of PPARγ expression, a transcription factor expressed in pre-adipocytes. In contrast, additional Wnt4 decreased the mRNA level of ADRP, a target gene of PPARγ. Murine embryonic thymic lobes have also been transfected with LAP2α- or Wnt4-encoding lentiviral vectors. As expected LAP2α over-expression increased, while additional Wnt4 secretion suppressed PPARγ expression. Based on these pioneer experiments we propose that decreased Wnt activity and increased LAP2α expression provide the molecular basis during thymic senescence. We suggest that these molecular changes trigger thymic epithelial senescence accompanied by adipose involution. This process may either occur directly where epithelium can trans-differentiate into pre-adipocytes; or indirectly where first epithelial to mesenchymal transition (EMT) occurs followed by subsequent pre-adipocyte differentiation. The latter version fits better with literature data and is supported by the observed histological and molecular level changes

    Fully digital data processing during cardiovascular implantable electronic device follow-up in a high-volume tertiary center

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    Background Increasing numbers of patients with cardiovascular implantable electronic devices (CIEDs) and limited follow-up capacities highlight unmet challenges in clinical electrophysiology. Integrated software (MediConnect®) enabling fully digital processing of device interrogation data has been commercially developed to facilitate follow-up visits. We sought to assess feasibility of fully digital data processing (FDDP) during ambulatory device follow-up in a high-volume tertiary hospital to provide guidance for future users of FDDP software. Methods A total of 391 patients (mean age, 70 years) presenting to the outpatient department for routine device follow-up were analyzed (pacemaker, 44%; implantable cardioverter defibrillator, 39%; cardiac resynchronization therapy device, 16%). Results Quality of data transfer and follow-up duration were compared between digital (n = 265) and manual processing of device data (n = 126). Digital data import was successful, complete and correct in 82% of cases when early software versions were used. When using the most recent software version the rate of successful digital data import increased to 100%. Software-based import of interrogation data was complete and without failure in 97% of cases. The mean duration of a follow-up visit did not differ between the two groups (digital 18.7 min vs. manual data transfer 18.2 min). Conclusions FDDP software was successfully implemented into the ambulatory follow-up of patients with implanted pacemakers and defibrillators. Digital data import into electronic patient management software was feasible and supported the physician’s workflow. The total duration of follow-up visits comprising technical device interrogation and clinical actions was not affected in the present tertiary center outpatient cohort

    Systematic substrate identification indicates a central role for the metalloprotease ADAM10 in axon targeting and synapse function

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    Metzincin metalloproteases have major roles in intercellular communication by modulating the function of membrane proteins. One of the proteases is the a-disintegrin-and-metalloprotease 10 (ADAM10) which acts as alpha-secretase of the Alzheimer\u27s disease amyloid precursor protein. ADAM10 is also required for neuronal network functions in murine brain, but neuronal ADAM10 substrates are only partly known. With a proteomic analysis of Adam10-deficient neurons we identified 91, mostly novel ADAM10 substrate candidates, making ADAM10 a major protease for membrane proteins in the nervous system. Several novel substrates, including the neuronal cell adhesion protein NrCAM, are involved in brain development. Indeed, we detected mistargeted axons in the olfactory bulb of conditional ADAM10-/- mice, which correlate with reduced cleavage of NrCAM, NCAM and other ADAM10 substrates. In summary, the novel ADAM10 substrates provide a molecular basis for neuronal network dysfunctions in conditional ADAM10-/- mice and demonstrate a fundamental function of ADAM10 in the brain

    Buiding in Dubai and Abu Dhabi - Field excursion of the faculty of civil engineering of the HTWG Konstanz 2009

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    Die 1,8-Millionenstadt Dubai und die Vereinigten Arabischen Emirate sind eine der Regionen der Welt mit den größten Bauaktivitäten. Der Exkursionsbericht schildert die Eindrücke bei der Exkursion der Fakultät Bauingenieurwesen der HTWG Konstanz im März 2009. Auf dem Programm standen die Baustellen der künstlichen Palmeninsel "Palm Jebel Ali", des "Iris Bay"-Turms mit seiner außergewöhnlichen Architektur sowie des "Latifa Tower", einem "normalen" Hochhaus von 255 Meter Höhe. Geotechnik im Wüstensand unter der Leitung deutscher Firmen waren ebenso zu sehen wie der Bau des weltweit größten Trinkwasserreservoirs. Weitere Höhepunkte der Reise waren die Baustellen des "Khalifa National Stadium" und der 1455 Meter langen Saadiyat-Brücke in Abu Dhabi, die die zukünftige Kulturmeile Abu Dhabis auf der Saadiyat Insel mit dem Festland verbinden wird.Dubai and the United Arab Emirates (UAE) are one of the regions in the world with the greatest building activities. The report depicts the impressions during a student field excursion of the Faculty of Civil Engineering of the University of Applied Sciences Konstanz, Germany, in March 2009

    Glioblastomas with primitive neuronal component harbor a distinct methylation and copy‑number profle with inactivation of TP53, PTEN, and RB1

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    Glioblastoma IDH-wildtype presents with a wide histological spectrum. Some features are so distinctive that they are considered as separate histological variants or patterns for the purpose of classification. However, these usually lack defined (epi-)genetic alterations or profiles correlating with this histology. Here, we describe a molecular subtype with overlap to the unique histological pattern of glioblastoma with primitive neuronal component. Our cohort consists of 63 IDH-wildtype glioblastomas that harbor a characteristic DNA methylation profile. Median age at diagnosis was 59.5 years. Copy-number variations and genetic sequencing revealed frequent alterations in TP53, RB1 and PTEN, with fewer gains of chromosome 7 and homozygous CDKN2A/B deletions than usually described for IDH-wildtype glioblastoma. Gains of chromosome 1 were detected in more than half of the cases. A poorly differentiated phenotype with frequent absence of GFAP expression, high proliferation index and strong staining for p53 and TTF1 often caused misleading histological classification as carcinoma metastasis or primitive neuroectodermal tumor. Clinically, many patients presented with leptomeningeal dissemination and spinal metastasis. Outcome was poor with a median overall survival of only 12 months. Overall, we describe a new molecular subtype of IDH-wildtype glioblastoma with a distinct histological appearance and genetic signature.publishedVersio
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