1,024 research outputs found

    Diseño de la trama urbana y cobertura de las redes de transporte público

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    Una de las claves en su uso del transporte público es la accesibilidad de la población a las paradas o estaciones. Los planificadores del transporte han buscado siempre localizaciones de paradas y estaciones en espacios con un volumen importante de población residente y/o empleo en su entorno inmediato. En los últimos años, se conjugan también políticas urbanísticas para generar nuevos desarrollos urbanos orientados al uso del transporte público. Se busca potenciar las llamadas 3D: densidad, diversidad de usos y diseño urbano. En esta comunicación el objetivo es analizar cómo influye el diseño de la trama urbana en la cobertura de las redes de transporte público (cantidad de población y el empleo en el entorno próximo de las estaciones). La metodología se apoya en el uso de Sistemas de Información Geográfica, sobre los que se han diseñado varios tipos de viarios, y para los que miden las superficies cubiertas y las distancias recorridas a estaciones localizadas en el centro de cada uno de ellos. Posteriormente, se hace un ejercicio de simulación donde se ha tomado el Metro de la ciudad de Madrid, y se han superpuesto sobre todas las estaciones de la red cada uno de los viarios tipo. Así, es posible calcular la población y el empleo cubiertos para cada uno de los escenarios tipo y compararla con la cobertura y la calidad de acceso a las estaciones a través del viario real de la ciudad. Al mantenerse fija las distribuciones de población y empleo, las diferencias se explican exclusivamente por el diseño de la trama urbana. Los resultados muestran como viarios orientados las estaciones incrementan notablemente la población y el empleo cubiertos

    Conformally rescaled spacetimes and Hawking radiation

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    We study various derivations of Hawking radiation in conformally rescaled metrics. We focus on two important properties, the location of the horizon under a conformal transformation and its associated temperature. We find that the production of Hawking radiation cannot be associated in all cases to the trapping horizon because its location is not invariant under a conformal transformation. We also find evidence that the temperature of the Hawking radiation should transform simply under a conformal transformation, being invariant for asymptotic observers in the limit that the conformal transformation factor is unity at their location.Comment: 22 pages, version submitted to journa

    Dinâmica de decomposição e composição química de palhada de cana-de-açúcar no Cerrado.

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    A decomposição de resíduos vegetais de cana-de-açúcar dispensa a queima da palhada e promove melhorias na conservação do solo com a redução de perdas de água e de nutrientes. Assim, este trabalho teve como objetivo avaliar as relações entre a decomposição da palhada e a composição química desses resíduos em área de cana-de-açúcar na Usina Goiasa, em Goiatuba GO-Brasil. As amostras foram armazenadas em litter bags e colocadas no campo, sob a camada de palhada de cana-de-açúcar, sendo retiradas periodicamente durante 563 dias para a quantificação da decomposição, análise bromatológica (lignina, FDA e FDN) e de nitrogênio (N) total dos resíduos remanescentes. A meia vida dos resíduos de cana-de-açúcar foi de 118 dias. Após 365 dias a quantidade remanescente de resíduos foi de 36% em relação à massa inicial. Os teores de N total aumentaram ao longo das fases de decomposição dos resíduos e diminuíram apenas a partir dos 330 dias de decomposição. A decomposição relativamente lenta dos resíduos vegetais de cana-de-açúcar pode ser atribuída aos valores bastante elevados de C/N e lignina/N nesses resíduos, onde houve forte correlação entre quantidade de resíduos remanescentes, e o decaimento de celulose e C:N

    Direct Mediation and Metastable Supersymmetry Breaking for SO(10)

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    We examine a metastable N=1\mathcal{N}=1 Macroscopic SO(N) SQCD model of Intriligator, Seiberg and Shih (ISS). We introduce various baryon and meson deformations, including multitrace operators and explore embedding an SO(10) parent of the standard model into two weakly gauged flavour sectors. Direct fundamental messengers and the symmetric pseudo-modulus messenger mediate SUSY breaking to the MSSM. Gaugino and sfermion masses are computed and compared for each deformation type. We also explore reducing the rank of the magnetic quark matrix of the ISS model and find an additional fundamental messenger.Comment: 43 pages, Latex. Version to appear in JHEP

    Machine intelligence decrypts β-lapachone as an allosteric 5-lipoxygenase inhibitor.

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    Using machine learning, targets were identified for β-lapachone. Resorting to biochemical assays, β-lapachone was validated as a potent, ligand efficient, allosteric and reversible modulator of 5-lipoxygenase (5-LO). Moreover, we provide a rationale for 5-LO modulation and show that inhibition of 5-LO is relevant for the anticancer activity of β-lapachone. This work demonstrates the power of machine intelligence to deconvolute complex phenotypes, as an alternative and/or complement to chemoproteomics and as a viable general approach for systems pharmacology studies

    Modulation of Androgen Receptor Signaling in Hormonal Therapy-Resistant Prostate Cancer Cell Lines

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    Background: Prostate epithelial cells depend on androgens for survival and function. In (early) prostate cancer (PCa) androgens also regulate tumor growth, which is exploited by hormonal therapies in metastatic disease. The aim of the present study was to characterize the androgen receptor (AR) response in hormonal therapy-resistant PC346 cells and identify potential disease markers. Methodology/Principal Findings: Human 19K oligoarrays were used to establish the androgen-regulated expression profile of androgen-responsive PC346C cells and its derivative therapy-resistant sublines: PC346DCC (vestigial AR levels), PC346Flu1 (AR overexpression) and PC346Flu2 (T877A AR mutation). In total, 107 transcripts were differentially-expressed in PC346C and derivatives after R1881 or hydroxyflutamide stimulations. The AR-regulated expression profiles reflected the AR modifications of respective therapy-resistant sublines: AR overexpression resulted in stronger and broader transcriptional response to R1881 stimulation, AR down-regulation correlated with deficient response of AR-target genes and the T877A mutation resulted in transcriptional response to both R1881 and hydroxyflutamide. This AR-target signature was linked to multiple publicly available cell line and tumor derived PCa databases, revealing that distinct functional clusters were differentially modulated during PCa progression. Differentiation and secretory functions were up-regulated in primary PCa but repressed i

    Dialetheism in Action: A New Strategy for Solving the Equal Validity Paradox

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    This paper starts from the Equal Validity Paradox, a paradoxical argument connected to the so-called phenomenon of faultless disagreement. It is argued that there are at least six strategies for solving the paradox. After presenting the first five strategies and their main problems, the paper focuses on the sixth strategy which rejects the assumption that every proposition cannot be both true a false. Dialetheism is the natural candidate for developing strategy six. After presenting strategy six in detail, we formulate a normative problem for the dialetheist and offer a tentative solution to it. We then elaborate further considerations connecting strategy six to pluralism about truth and logic. Even if strategy six is a hard path to take, its scrutiny highlights some important points on truth, logic and the norms for acceptance and rejection

    The role of the segmentation gene hairy in Tribolium

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    Hairy stripes in Tribolium are generated during blastoderm and germ band extension, but a direct role for Tc-h in trunk segmentation was not found. We have studied here several aspects of hairy function and expression in Tribolium, to further elucidate its role. First, we show that there is no functional redundancy with other hairy paralogues in Tribolium. Second, we cloned the hairy orthologue from Tribolium confusum and show that its expression mimics that of Tribolium castaneum, implying that stripe expression should be functional in some way. Third, we show that the dynamics of stripe formation in the growth zone is not compatible with an oscillatory mechanism comparable to the one driving the expression of hairy homologues in vertebrates. Fourth, we use parental RNAi experiments to study Tc-h function and we find that mandible and labium are particularly sensitive to loss of Tc-h, reminiscent of a pair-rule function in the head region. In addition, lack of Tc-h leads to cell death in the gnathal region at later embryonic stages, resulting in a detachment of the head. Cell death patterns are also altered in the midline. Finally, we have analysed the effect of Tc-h knockdown on two of the target genes of hairy in Drosophila, namely fushi tarazu and paired. We find that the trunk expression of Tc-h is required to regulate Tc-ftz, although Tc-ftz is itself also not required for trunk segmentation in Tribolium. Our results imply that there is considerable divergence in hairy function between Tribolium and Drosophila

    The Role of Individual Variables, Organizational Variables and Moral Intensity Dimensions in Libyan Management Accountants’ Ethical Decision Making

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    This study investigates the association of a broad set of variables with the ethical decision making of management accountants in Libya. Adopting a cross-sectional methodology, a questionnaire including four different ethical scenarios was used to gather data from 229 participants. For each scenario, ethical decision making was examined in terms of the recognition, judgment and intention stages of Rest’s model. A significant relationship was found between ethical recognition and ethical judgment and also between ethical judgment and ethical intention, but ethical recognition did not significantly predict ethical intention—thus providing support for Rest’s model. Organizational variables, age and educational level yielded few significant results. The lack of significance for codes of ethics might reflect their relative lack of development in Libya, in which case Libyan companies should pay attention to their content and how they are supported, especially in the light of the under-development of the accounting profession in Libya. Few significant results were also found for gender, but where they were found, males showed more ethical characteristics than females. This unusual result reinforces the dangers of gender stereotyping in business. Personal moral philosophy and moral intensity dimensions were generally found to be significant predictors of the three stages of ethical decision making studied. One implication of this is to give more attention to ethics in accounting education, making the connections between accounting practice and (in Libya) Islam. Overall, this study not only adds to the available empirical evidence on factors affecting ethical decision making, notably examining three stages of Rest’s model, but also offers rare insights into the ethical views of practising management accountants and provides a benchmark for future studies of ethical decision making in Muslim majority countries and other parts of the developing world
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