1,001 research outputs found

    An Empirical Analysis of the External Finance Premium of Public Non-Financial Corporations in Brazil

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    Our objective in this paper is to analyze empirically the relationship between the external finance premium of non-financial corporations in Brazil with their default probability and with their demand for inventories. As for the former relation, we find that corporations that have greater external finance premium have greater probability of default. As for the latter, we find that the external finance premium is positive and statistically significantly correlated. The results confirm previous results of the literature that indicate that the balance sheet channel of monetary policy is relevant in Brazil.

    A reliability study of the new back strain monitor based on clinical trials

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    A new Back Strain Monitor (BSM) device has been developed in order to measure, record and analyze movements of the lower back. The purpose of this study was to examine the inter-tester and the intra-tester reliability of the movement measurements given by the BSM accelerometers, and compare it with the reliability of two other conventional measurement methods: the Double Inclinometer method (DI) and the Modified-Modified Schober (MMS) method. The clinical studies included 23 participants (16 males, 7 females) with no recent history of lower back pain, who wore the device during a combination of different anatomical movements (flexion, extension, left lateral flexion and right lateral flexion of the lumber spine). The tests were conducted by three therapists (testers). The reliability results for the BSM accelerometers clearly outperform the results obtained for the DI and the MMS methods. The inter-tester reliability gives the Intra-Class Correlation (ICC) value of 0.95 for the BSM flexion, 0.89 for the DI flexion and 0.74 for the MMS. The intra-tester reliability gives the ICC value of 0.99 for BSM flexion, 0.94 for DI flexion and 0.77 for the MMS. The BSM accelerometers were highly reliable in assessing back movements, measuring these movements with less error than the DI and MMS methods

    Modelling the impact of wildfire smoke on driving speed

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    Traffic models can be used to study evacuation scenarios during wildland-urban interface fires and identify the ability of a community to reach a safe place. In those scenarios, wildfire smoke can reduce visibility conditions on the road. This can have serious implications on the evacuation effectiveness since drivers would reduce their speed in relation to the optical density on the road. To date, there is no traffic model which explicitly represents the impact of reduced visibility conditions on traffic evacuation flow. This paper makes use of an experimental dataset collected in a virtual reality environment to calibrate two widely used macroscopic traffic models (the Lighthill-Whitham-Richards and the Van Aerde models) in order to account for the impact of reduced visibility conditions on driving speed. An application of the calibrated traffic model considering the impact of smoke has been performed using the WUI-NITY platform, an open multi-physics platform which includes wildfire spread, pedestrian response and traffic modelling. A dedicated verification test has been developed and performed considering different values of optical densities of smoke and traffic densities to ensure the model has been implemented correctly in WUI-NITY. A case study that demonstrates the applicability of the model to real life scenarios was also implemented, based on data from an evacuation drill. This paper shows that the presence of smoke on the road can significantly decrease movement speed and increase evacuation times thus highlighting the need for inclusion of this factor in traffic evacuation models applied for wildland-urban interface fire scenarios

    Guidance on Design and Construction of the Built Environment Against Wildland Urban Interface Fire Hazard: A Review

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    Wildland-Urban Interface (WUI) fires, a worldwide problem, are gaining more importance over time due to climate change and increased urbanization in WUI areas. Some jurisdictions have provided standards, codes and guidelines, which may greatly help planning, prevention and protection against wildfires. This work presents a wide systematic review of standards, codes and guidelines for the design and construction of the built environment against WUI fire hazard from North American, European, Oceanic countries, alongside with trans-national codes. The main information reviewed includes: the definition of WUI hazards, risk areas and related severity classes, the influence of land and environmental factors, the requirements for building materials, constructions, utilities, fire protection measures and road access. Some common threads among the documents reviewed have been highlighted. They include similar attempts at: (a) defining WUI risk areas and severity classes, (b) considering land factors including the defensible space (also known as ignition zones), (c) prescribing requirements for buildings and access. The main gaps highlighted in the existing standards/guidelines include lacks of detailed and widespread requirements for resources, fire protection measures, and lacks of taking into account environmental factors in detail. The main design and construction principles contained in the reviewed documents are largely based on previous research and/or good practices. Hence, the main contributions of this paper consist in: (a) systematically disseminate these guidance concepts, (b) setting a potential basis for the development of standards/guidelines in other jurisdictions lacking dedicated WUI fire design guidance, (c) highlighting gaps in existing standards/guidelines to be addressed by current and future research

    An axis-free overset grid in spherical polar coordinates for simulating 3D self-gravitating flows

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    A type of overlapping grid in spherical coordinates called the Yin-Yang grid is successfully implemented into a 3D version of the explicit Eulerian grid-based code PROMETHEUS including self-gravity. The modified code successfully passed several standard hydrodynamic tests producing results which are in very good agreement with analytic solutions. Moreover, the solutions obtained with the Yin-Yang grid exhibit no peculiar behaviour at the boundary between the two grid patches. The code has also been successfully used to model astrophysically relevant situations, namely equilibrium polytropes, a Taylor-Sedov explosion, and Rayleigh-Taylor instabilities. According to our results, the usage of the Yin-Yang grid greatly enhances the suitability and efficiency of 3D explicit Eulerian codes based on spherical polar coordinates for astrophysical flows.Comment: 15 pages, 17 figures, 2 tables, accepted for publication in A&

    Heat shock induced changes of adipokines gene expression in 3T3-L1 adipocytes

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    To study the effects of heat shock on adipokines gene expression 3T3-L1 adipocytes were used. Heat shock differently affected gene expression of leptin, adiponectin and acylation stimulating protein (ASP): exposure of cells to temperature higher than 39°C caused upregulation of leptin and downregulation of adiponectin and ASP genes. The present study provides the first evidence about the effects of heat shock on adipokines gene expression. Changes in gene expression of the three adipokines may help to explain the alteration of lipid metabolism and liver functionality occurring in animals exposed to hot conditions

    Genetics of Late-Onset Alzheimer's Disease: Update from the Alzgene Database and Analysis of Shared Pathways

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    The genetics of late-onset Alzheimer's disease (LOAD) has taken impressive steps forwards in the last few years. To date, more than six-hundred genes have been linked to the disorder. However, only a minority of them are supported by a sufficient level of evidence. This review focused on such genes and analyzed shared biological pathways. Genetic markers were selected from a web-based collection (Alzgene). For each SNP in the database, it was possible to perform a meta-analysis. The quality of studies was assessed using criteria such as size of research samples, heterogeneity across studies, and protection from publication bias. This produced a list of 15 top-rated genes: APOE, CLU, PICALM, EXOC3L2, BIN1, CR1, SORL1, TNK1, IL8, LDLR, CST3, CHRNB2, SORCS1, TNF, and CCR2. A systematic analysis of gene ontology terms associated with each marker showed that most genes were implicated in cholesterol metabolism, intracellular transport of beta-amyloid precursor, and autophagy of damaged organelles. Moreover, the impact of these genes on complement cascade and cytokine production highlights the role of inflammatory response in AD pathogenesis. Gene-gene and gene-environment interactions are prominent issues in AD genetics, but they are not specifically featured in the Alzgene database
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