1,855 research outputs found

    Assessing Eli Broad\u27s Assault on Public School System Leadership. A response to The Broad Challenge to Democratic Leadership: The Other Crisis in Education.

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    Eli Broad’s approach to reforming urban public education does not recognize his own self-interest in promoting changes within such educational systems, a classic problem of misrecognition. The Broad agenda is an assault on the notion of the mission of public education as a service instead of a for-profit enterprise concerned with making money for the owners and stock holders. This article examines the backgrounds of the graduates of the Broad Superintendents Academy and raises critical issues such as how can Broad claim that graduate preparation in educational administration is unnecessary when at least half of his own graduates already have advanced degrees from universities in the field and occupy high-level central office positions? Broad\u27s remedies harken back to those advanced by Frederick Winslow Taylor, the creator of scientific management

    Bugging Out: Darknets as Parasites of Large-scale Media Objects

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    Platforms and infrastructures have quickly become seminal concepts to understand large-scale computational systems. The difference between a platform and an infrastructure is subject to debate. In this paper, we use the concept of the darknet to describe how infrastructure tends toward being public with other things where platforms tend to private relations. The darknet reveals these relations negatively, as we discuss, by turning these media objects into that which they desire not to be. We analyze these negative relations through the concept of the parasite developed by Michel Serres. Through following how darknets parasite both platforms and infrastructure, we suggest a need to develop new concepts to understand the diversity of relations now possible in a network society

    Glutathione accelerates sodium channel inactivation in excised rat axonal membrane patches

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    The effects of glutathione were studied on the gating behaviour of sodium channels in membrane patches of rat axons. Depolarizing pulses from –120 to –40 mV elicited sodium currents of up to 500 pA, indicating the simultaneous activation of up to 250 sodium channels. Inactivation of these channels in the excised, inside-out configuration was fitted by two time constants ( h1=0.81 ms; h2= 5.03 ms) and open time histograms at 0 mV revealed a biexponential distribution of channel openings ( short=0.28 ms; long=3.68 ms). Both, the slow time constant of inactivation and the long lasting single channel openings disappeared after addition of the reducing agent glutathione (2–5 mM) to the bathing solution. Sodium channels of excised patches with glutathione present on the cytoplasmatic face of the membrane had inactivation kinetics similar to channels recorded in the cell-attached configuration. These observations indicate that redox processes may contribute to the gating of axonal sodium channels

    A systematic review of the effectiveness of docetaxel and mitoxantrone for the treatment of metastatic hormone-refractory prostate cancer

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    A systematic review was performed to evaluate the clinical effectiveness of docetaxel in combination with prednisolone (docetaxel is licensed in the UK for use in combination with prednisone or prednisolone for the treatment of patients with metastatic hormone-refractory prostate cancer. Prednisone is not used in the UK, but it is reasonable to use docetaxel plus prednisone data in this review of docetaxel plus prednisolone) for the treatment of metastatic hormone-refractory prostate cancer. A scoping search identified a trial of docetaxel plus prednisone vs mitoxantrone plus prednisone, but did not identify any trials comparing docetaxel plus prednisolone/prednisone with any other treatments. Therefore, we considered additional indirect evidence that would enable a comparison of docetaxel plus prednisolone/prednisone with other chemotherapy regimens and active supportive care. Systematic searching (upto April 2005) identified seven randomised controlled trials. One large well-conducted trial assessed docetaxel plus prednisone vs mitoxantrone plus prednisone; this showed statistically significant improvements with 3-weekly docetaxel in terms of overall survival, quality of life, pain response and PSA decline. Two other chemotherapy regimens that included docetaxel with estramustine also showed improved outcomes in comparison with mitoxantrone plus prednisone. Three trials that compared mitoxantrone plus corticosteroids with corticosteroids alone were identified and their results for overall survival combined, which showed very little difference between the two groups. The addition of clodronate to mitoxantrone plus prednisone showed no significant differences in comparison with mitoxantrone plus prednisone alone. The evidence suggests that chemotherapy regimens containing 3-weekly docetaxel are superior to mitoxantrone or corticosteroids alone

    EPI-001, A Compound Active against Castration-Resistant Prostate Cancer, Targets Transactivation Unit 5 of the Androgen Receptor

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    ACKNOWLEDGEMENTS We thank J. M. Valverde (IRB) as well as the NMR facilities of the University of Barcelona (CCiT UB) and the Instituto de Química Física Rocasolano (IQFR, CSIC) for their assistance in, respectively, protein production and NMR. This work was supported by IRB, ICREA (X.S.), Obra Social “la Caixa” (Fellowship to E.D.M. and CancerTec grants to X.S.) MICINN (CTQ2009-08850 to X.S.), MINECO (BIO2012-31043 to X.S.; CTQ2014-56361-P to A.R), Marató de TV3 (102030 to X.S. and 102031 to E.E.P) the COFUND programme of the European Commission (C.T.W.P., A. R. and X.S.), the European Research Council (CONCERT, contract number 648201, to X.S.), the Ramón y Cajal program of MICINN (RYC-2011-07873 to C.W.B.) the Serra Hunter Programme (E.E.P.) and AGAUR (SGR-2014-56RR14 to E.E.P). IRB Barcelona is the recipient of a Severo Ochoa Award of Excellence from MINECO (Government of Spain)Peer reviewedPostprin

    Quasi-Zero Dimensional Halide Perovskite Derivates: Synthesis, Status, and Opportunity

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    In recent decades, many technological advances have been enabled by nanoscale phenomena, giving rise to the field of nanotechnology. In particular, unique optical and electronic phenomena occur on length scales less than 10 nanometres, which enable novel applications. Halide perovskites have been the focus of intense research on their optoelectronic properties and have demonstrated impressive performance in photovoltaic devices and later in other optoelectronic technologies, such as lasers and light-emitting diodes. The most studied crystalline form is the three-dimensional one, but, recently, the exploration of the low-dimensional derivatives has enabled new sub-classes of halide perovskite materials to emerge with distinct properties. In these materials, low-dimensional metal halide structures responsible for the electronic properties are separated and partially insulated from one another by the (typically organic) cations. Confinement occurs on a crystal lattice level, enabling bulk or thin-film materials that retain a degree of low-dimensional character. In particular, quasi-zero dimensional perovskite derivatives are proving to have distinct electronic, absorption, and photoluminescence properties. They are being explored for various technologies beyond photovoltaics (e.g. thermoelectrics, lasing, photodetectors, memristors, capacitors, LEDs). This review brings together the recent literature on these zero-dimensional materials in an interdisciplinary way that can spur applications for these compounds. The synthesis methods, the electrical, optical, and chemical properties, the advances in applications, and the challenges that need to be overcome as candidates for future electronic devices have been covered

    Calculating partial expected value of perfect information via Monte Carlo sampling algorithms

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    Partial expected value of perfect information (EVPI) calculations can quantify the value of learning about particular subsets of uncertain parameters in decision models. Published case studies have used different computational approaches. This article examines the computation of partial EVPI estimates via Monte Carlo sampling algorithms. The mathematical definition shows 2 nested expectations, which must be evaluated separately because of the need to compute a maximum between them. A generalized Monte Carlo sampling algorithm uses nested simulation with an outer loop to sample parameters of interest and, conditional upon these, an inner loop to sample remaining uncertain parameters. Alternative computation methods and shortcut algorithms are discussed and mathematical conditions for their use considered. Maxima of Monte Carlo estimates of expectations are biased upward, and the authors show that the use of small samples results in biased EVPI estimates. Three case studies illustrate 1) the bias due to maximization and also the inaccuracy of shortcut algorithms 2) when correlated variables are present and 3) when there is nonlinearity in net benefit functions. If relatively small correlation or nonlinearity is present, then the shortcut algorithm can be substantially inaccurate. Empirical investigation of the numbers of Monte Carlo samples suggests that fewer samples on the outer level and more on the inner level could be efficient and that relatively small numbers of samples can sometimes be used. Several remaining areas for methodological development are set out. A wider application of partial EVPI is recommended both for greater understanding of decision uncertainty and for analyzing research priorities

    Influence of Schistosoma mansoni and Hookworm Infection Intensities on Anaemia in Ugandan Villages.

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    BACKGROUND: The association of anaemia with intestinal schistosomiasis and hookworm infections are poorly explored in populations that are not limited to children or pregnant women. METHODS: We sampled 1,832 individuals aged 5-90 years from 30 communities in Mayuge District, Uganda. Demographic, village, and parasitological data were collected. Infection risk factors were compared in ordinal logistic regressions. Anaemia and infection intensities were analyzed in multilevel models, and population attributable fractions were estimated. FINDINGS: Household and village-level predictors of Schistosoma mansoni and hookworm were opposite in direction or significant for single infections. S. mansoni was found primarily in children, whereas hookworm was prevalent amongst the elderly. Anaemia was more prevalent in individuals with S. mansoni and increased by 2.86 fold (p-value<0.001) with heavy S. mansoni infection intensity. Individuals with heavy hookworm were 1.65 times (p-value = 0.008) more likely to have anaemia than uninfected participants. Amongst individuals with heavy S. mansoni infection intensity, 32.0% (p-value<0.001) of anaemia could be attributed to S. mansoni. For people with heavy hookworm infections, 23.7% (p-value = 0.002) of anaemia could be attributed to hookworm. A greater fraction of anaemia (24.9%, p-value = 0.002) was attributable to heavy hookworm infections in adults (excluding pregnant women) as opposed to heavy hookworm infections in school-aged children and pregnant women (20.2%, p-value = 0.001). CONCLUSION: Community-based surveys captured anaemia in children and adults affected by S. mansoni and hookworm infections. For areas endemic with schistosomiasis or hookworm infections, WHO guidelines should include adults for treatment in helminth control programmes.This is the final version of the article. It first appeared from PLoS via http://dx.doi.org/10.1371/journal.pntd.000419
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