581 research outputs found

    Educating English Learners During the Pandemic: Insights from Experts, Advocates, and Practitioners

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    There is a growing body of evidence about the disproportionate impact the pandemic had on English learners (ELs). We sought to capture the complexity of learning conditions for this student population during the COVID-19 pandemic by interviewing 20 EL education leaders. These experts' experiences revealed that while remote learning posed significant challenges to EL education and services, educators improvised, collaborated, and continued to innovate throughout the pandemic. To help EL students moving forward, education leaders on all levels must acknowledge both the struggle and perseverance that shaped their educational experiences during the pandemic

    Lost in translation: Exposing hidden compiler optimization opportunities

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    Existing iterative compilation and machine-learning-based optimization techniques have been proven very successful in achieving better optimizations than the standard optimization levels of a compiler. However, they were not engineered to support the tuning of a compiler's optimizer as part of the compiler's daily development cycle. In this paper, we first establish the required properties which a technique must exhibit to enable such tuning. We then introduce an enhancement to the classic nightly routine testing of compilers which exhibits all the required properties, and thus, is capable of driving the improvement and tuning of the compiler's common optimizer. This is achieved by leveraging resource usage and compilation information collected while systematically exploiting prefixes of the transformations applied at standard optimization levels. Experimental evaluation using the LLVM v6.0.1 compiler demonstrated that the new approach was able to reveal hidden cross-architecture and architecture-dependent potential optimizations on two popular processors: the Intel i5-6300U and the Arm Cortex-A53-based Broadcom BCM2837 used in the Raspberry Pi 3B+. As a case study, we demonstrate how the insights from our approach enabled us to identify and remove a significant shortcoming of the CFG simplification pass of the LLVM v6.0.1 compiler.Comment: 31 pages, 7 figures, 2 table. arXiv admin note: text overlap with arXiv:1802.0984

    El papel del estrés oxidativo en la disfunción endotelial de la aterosclerosis

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    La enfermedad cardiovascular es una causa importante de morbilidad y mortalidad en el mundo. Resulta de la oclusión trombótica de las arterias como consecuencia de la rotura de una placa de ateroma, misma que se genera por disfunción endotelial e inflamación crónica, que a su vez son producidas por un estado de estrés oxidativo del organismo, a causa de un desbalance en la producción de especies reactivas de oxígeno y la eficiencia de los sistemas antioxidantes. Se sabe que la progresión de la placa de ateroma genera también por sí misma inflamación y estrés oxidativo. El objetivo de esta revisión es presentar los mecanismos por los cuales el estrés oxidativo es causa y consecuencia de la ateroesclerosis, llevando a un daño continuo del endotelio.La enfermedad cardiovascular es una causa importante de morbilidad y mortalidad en el mundo. Resulta de la oclusión trombótica de las arterias como consecuencia de la rotura de una placa de ateroma, misma que se genera por disfunción endotelial e inflamación crónica, que a su vez son producidas por un estado de estrés oxidativo del organismo, a causa de un desbalance en la producción de especies reactivas de oxígeno y la eficiencia de los sistemas antioxidantes. Se sabe que la progresión de la placa de ateroma genera también por sí misma inflamación y estrés oxidativo. El objetivo de esta revisión es presentar los mecanismos por los cuales el estrés oxidativo es causa y consecuencia de la ateroesclerosis, llevando a un daño continuo del endotelio

    Production and characterization of biochar from industrial sludge for potential agronomic use

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    Raman Micro Spectroscopy Study of the Interaction of Vincristine with A549 Cells Supported by Expression Analysis of bcl-2 Protein

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    Understanding the interaction of anticancer drugs with model cell lines is important to elucidate the mode of action of these drugs as well as to develop cost effective and rapid screening methods. Raman spectroscopy has been demonstrated to be a valuable technique for high throughput, noninvasive analysis. The interaction of vincristine with a human lung adenocarcinoma cell line (A549)was investigated using Raman micro spectroscopy. The results were correlated with parallel measurements from the MTT cytotoxicity assay, which yielded an IC50 value of 0.10 ± 0.03 μM. The Raman spectral data acquired from vincristine treated A549 cells was analysed to understand its interaction with the nucleus in the cell and elucidate DNA intercalation. The dose dependent spectral changes in the nucleus are analysed by PLS-Jack knifing for the identification of the more significant changes associated with the mode of action of the drug. Results are correlated with a similar dose dependent expression analysis of the bcl-2 protein, an anti-apoptotic protein associated with DNA damage, in the vincristine treated A549 cells using flow cytometry. The results indicate the co-existence of two modes of action, microtubule binding at low doses and DNA intercalation at high doses

    Removal of Pb, Cu, Cd, and Zn Present in Aqueous Solution Using Coupled Electrocoagulation-Phytoremediation Treatment

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    Este estudio se evaluó un tratamiento acoplado de Electrocoagulación – Fitorremediación, con la finalidad de remover los metales pesados (Pb, Cu, Cd y Zn) presentes en agua residual minera y que esta agua pueda ser se reusóThis study presents the results of a coupled electrocoagulation-phytoremediation treatment for the reduction of copper, cadmium, lead, and zinc, present in aqueous solution. The electrocoagulation was carried out in a batch reactor using aluminum electrodes in parallel arrangement; the optimal conditions were current density of 8 mA/cm2 and operating time of 180 minutes. For phytoremediation the macrophytes, Typha latifolia L., were used during seven days of treatment. The results indicated that the coupled treatment reduced metal concentrations by 99.2% Cu, 81.3% Cd, and 99.4% Pb, while Zn increased due to the natural concentrations of the plant used. 1.Facultad de Química, UAEMe

    Cell Death Pathways in Directly Irradiated Cells and Cells Exposed to Medium from Irradiated Cells

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    Purpose: The aim of this study was to compare levels of apoptosis, necrosis, mitotic cell death and senescence after treatment with both direct radiation and irradiated cell conditioned medium. Materials and methods: Human keratinocytes (HaCaT cell line) were irradiated (0.005, 0.05 and 0.5 Gy) using a cobalt 60 teletherapy unit. For bystander experiments, the medium was harvested from donor HaCaT cells one hour after irradiation and transferred to recipient HaCaT cells. Clonogenic assay, apoptosis, necrosis, mitotic cell death, senescence and cell cycle analysis were measured in both directly irradiated cells and bystander cells Results: A reduction in cell survival was observed for both directly irradiated cells and irradiated cell conditioned medium (ICCM) treated cells. Early apoptosis and necrosis was observed predominantly after direct irradiation. An increase in the number of cells in G2/M phase was observed at 6 and 12 hours which led to mitotic cell death after 72 hours following direct irradiation and ICCM treatment. No senescence was observed in the HaCaT cell line following either direct irradiation or treatment with ICCM. Conclusion: This study has shown that directly irradiated cells undergo apoptosis, necrosis and mitotic cell death whereas ICCM treated cells predominantly undergo mitotic cell deat
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