1,909 research outputs found

    A hybrid model for information security risk assessment

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    Many industry standards and methodologies were introduced which has brought forth the management of threats assessment and risk management of information assets in a systematic manner. This paper will review and analyze the main processes followed in IT risk management frameworks from the perspective of the threat analysis process using a threat modeling methodology. In this study, the authors propose a new assessment model which shows that systematic threat analysis is an essential element to be considered as an integrated process within IT risk management frameworks. The new proposed model complements and fulfills the gap in the practice of assessing information security risks

    Roles of mitogen-activated protein kinases and angiotensin II in renal development

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    Experimental and clinical evidence suggests that angiotensin II (AII) participates in renal development. Renal AII content is several-fold higher in newborn rats and mice than in adult animals. AII receptors are also expressed in higher amounts in the kidneys of newborn rats. The kidneys of fetuses whose mother received a type 1 AII receptor (AT1) antagonist during gestation present several morphological alterations. Mutations in genes that encode components of the renin-angiotensin system are associated with autosomal recessive renal tubular dysgenesis. Morphological changes were detected in the kidneys of 3-week-old angiotensin-deficient mice. Mitogen-activated protein kinases (MAPKs) are important mediators that transduce extracellular stimuli to intracellular responses. The MAPK family comprises three major subgroups, namely extracellular signal-regulated protein kinase (ERK), c-jun N-terminal kinases (JNK), and p38 MAPK (p38). Important events in renal growth during nephrogenesis such as cellular proliferation and differentiation accompanied by apoptosis on a large scale can be mediated by MAPK pathways. A decrease in glomerulus number was observed in embryos cultured for 48 and 120 h with ERK or p38 inhibitors. Many effects of AII are mediated by MAPK pathways. Treatment with losartan during lactation provoked changes in renal function and structure associated with alterations in AT1 and type 2 AII (AT2) receptors and p-JNK and p-p38 expression in the kidney. Several studies have shown that AII and MAPKs play an important role in renal development. However, the relationship between the effects of AII and MAPK activation on renal development is still unclear.FAPESPCNP

    Bentonite functionalized with propyl sulfonic acid groups used as catalyst in esterification reactions

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    AbstractThe main objective of this work is the functionalization of bentonite from the Amazon (region) by the grafting of propyl sulfonic acid groups to catalyze the esterification reaction of acetic acid and 1-propanol. Functionalization was accomplished by anchoring, oxidation and acid activation of (3-mercaptopropyl)trimethoxysilane, (MTPS). The procedure gave acid properties to the raw bentonite. This material, acting as a catalyst, increased the reaction speed and improved the yield by about 12% compared to the uncatalyzed reaction. The functionalized bentonite was characterized by XRD, TG/DTA, FTIR, N2 adsorption/desorption at 77K and XRF, and the surface acidity was determined by titration

    Cognitive approaches and optical multispectral data for semi-automated classification of landforms in a rugged mountainous area

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    This paper introduces a new open source, knowledge-based framework for automatic interpretation of remote sensing images, called InterIMAGE. This framework owns a flexible modular architecture, in which image processing operators can be associated to both root and leaf nodes of the semantic network, which constitutes a differential strategy in comparison to other object-based image analysis platforms currently available. The architecture, main features as well as an overview on the interpretation strategy implemented in InterIMAGE is presented. The paper also reports an experiment on the classification of landforms. Different geomorphometric and textural attributes obtained from ASTER/Terra images were combined with fuzzy logic and drove the interpretation semantic network. Object-based statistical agreement indices, estimated from a comparison between the classified scene and a reference map, were used to assess the classification accuracy. The InterIMAGE interpretation strategy yielded a classification result with strong agreement and proved to be effective for the extraction of landforms

    Seminal quality, testicle and epididymis morphology of bulls fed a diet containing gossypol

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    The objective was to evaluate the effect of intake of free gossypol on sperm quality and morphology of the testicles and epididymis of Nelore bulls. Twelve bulls were fed diets containing 3.3g of free gossypol/bull/day (cottonseed) (Group 1, n = 6) and a diet free of gossypol (Group 2, n = 6), respectively. Semen samples were collected in the beginning and end of the experiment which lasted 73 days. In the end of the study the testes and epididymis of bulls were removed to study the effect of free gossypol on histological characteristics. The average consumption of 3.3g of free gossypol/bull/day (mean 7.1mg of free gossypol/kg/day) reduced motility and sperm concentration and increased the percentage of major and total sperm defects, as well as the animals showing testes with seminiferous tubules of smaller thickness, fewer layers of spermatogenic lineage cells, smaller epididymal epithelium thickness and smaller number of sperm within the epididymal ducts, compared to animals with a diet free of gossypol (Group 2). The consumption of 3.3g of free gossypol/bull/day led to changes in morphology and morphometry of the testes and epididymis and reduced sperm quality of bulls.Objetivou-se avaliar o efeito da ingestão de gossipol livre sobre a qualidade espermática e a morfologia dos testículos e dos epidídimos de touros da raça Nelore. Doze touros receberam dieta contendo 3,3g de gossipol livre/touro/dia (caroço de algodão) (Grupo 1, n=6) e dieta isenta de gossipol (Grupo 2, n=6), respectivamente. Foram realizadas coletas de sêmen no início e no final do experimento, que teve duração de 73 dias. Ao final do estudo, foram retirados os testículos e os epidídimos dos touros para se estudar o efeito do gossipol livre sobre as características histológicas. O consumo médio de 3,3g de gossipol livre/touro/dia (média 7,1mg de gossipol livre/kg/dia) reduziu a motilidade e a concentração espermática e aumentou a porcentagem de defeitos espermáticos maiores e totais. Além disso, os animais apresentaram testículos com túbulos seminíferos de menor espessura de parede, menor número de camadas de células espermatogênicas, menor espessura do epitélio epididimário e menor número de espermatozoide no interior dos ductos epidídimários, em relação aos animais com dieta isenta de gossipol (Grupo 2). O consumo de 3,3g de gossipol livre/touro/dia acarretou alterações na morfologia e na morfometria dos testículos e dos epidídimos e reduziu a qualidade espermática dos touros.Universidade de Cuiabá Faculdade de Medicina VeterináriaUFMS Faculdade de Medicina Veterinária e ZootecniaEpamigUniversidade Federal do Mato GrossoUNIFESP-EPMUNIFESP, EPMSciEL

    TRANSPIRATION OF TREE SPECIES IN DIFFERENT VERTICAL LAYERS OF A KANDYAN FOREST GARDEN

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    Water use of a forest ecosystem is: nn important determinant of the water balance of a wholewatershed. Kandyan Forest Gardens (KFGs) contain a mixture of different tree species. Thedifferent tree species are of different sizes and are arranged into distinct vertical canopy layers.The total water use of the KFG is determined by the transpiration rates of individual trees, whichform these different vertical layers.The study was conducted in a KGF at Pilapitiya, Pilimathalawa in the Mid-Country Wet Zone(WM3) during the period from Marci to July 2001. A vegetation survey showed that there were56 tree species in this KFG. Out cf these, three tree species representing three vertical canopylayers were selected for continuous measurement of transpiration. These were Jak (ArtocarpusheterophyIlus), toona (Toona ciliata) and Mahogany (Swietenia macrophylla) which representedupper, middle and lower canopy layers respectively. Transpiration of all trees was measured asthe sap flow in their trunks using two thermal methods. In jak (DBH = 40.5 ern) and toona(DBH=9cm), which had larger trunks, sap flow was measured using thermal dissipation probes.In mahogany, which had a smaller trunk (DBH=3cm), sap flow was measure using a dynagage.Solar radiation incident on the respe-ctive tree canopies were measured using tube solarimeters.Relative humidity in the open and inside the KFG was measured by two solid state humiditysensors. Soil moisture content at three soil depths (30, 60 and 120 em) was measured using thetaprobes. All measurements were done continuously at 30 second time intervals using a datalogger. The data were averaged every 5 minutes and stored in the logger.Detailed continuous measurements taken during a n-hour period (i.e. from 0000 hours on23.06.2001 to 2400 hours 25.06.20)1) were analysed. All three-tree species showed similardiurnal variation patterns in their S8P flow rates with maximum rates occurring between 1300and 1400 hours. Sap flow rate of jak was significantly greater than those of toon a and mahogany,which did not differ significantly. However, the velocity of sap flow was highest in the smallesttree, i.e. mahogany, and decreased with increasing sap wood cross-sectional area. The dailytranspiration rates oftoona and mahogany ranged from 19% to 27%. The incident solar radiationwas highest on the upper canopy tree (i.e. jak), Both the middle canopy (toona) and lowercanopy (mahogany) trees received similar levels of radiation because of the incomplete uppercanopy cover in the KFG. There was a clear linear relationship between daily transpiration of alltree species and the solar radiation levels received by the respective trees. This relationship canbe used to predict the daily water use of a given tree when there is no significant soil waterdeficit.The relative humidity (RH) under both open conditions and within the KFG showed a similarvariation pattern. However, RH within the KFG was slightly higher than that in the open.Transpiration rates of all tree species had negative linear relationships with the respective RHvalues experienced by them.

    Universal renormalization-group dynamics at the onset of chaos in logistic maps and nonextensive statistical mechanics

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    We uncover the dynamics at the chaos threshold μ∞\mu_{\infty} of the logistic map and find it consists of trajectories made of intertwined power laws that reproduce the entire period-doubling cascade that occurs for μ<μ∞\mu <\mu_{\infty}. We corroborate this structure analytically via the Feigenbaum renormalization group (RG) transformation and find that the sensitivity to initial conditions has precisely the form of a qq-exponential, of which we determine the qq-index and the qq-generalized Lyapunov coefficient λq\lambda _{q}. Our results are an unequivocal validation of the applicability of the non-extensive generalization of Boltzmann-Gibbs (BG) statistical mechanics to critical points of nonlinear maps.Comment: Revtex, 3 figures. Updated references and some general presentation improvements. To appear published as a Rapid communication of PR

    Phytoestrogen agathisflavone ameliorates neuroinflammation-induced by LPS and IL-1β and protects neurons in cocultures of glia/neurons

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    Inflammation and oxidative stress are common aspects of most neurodegenerative diseases in the central nervous system. In this context, microglia and astrocytes are central to mediating the balance between neuroprotective and neurodestructive mechanisms. Flavonoids have potent anti-inflammatory and antioxidant properties. Here, we have examined the anti-inflammatory and neuroprotective potential of the flavonoid agathisflavone (FAB), which is derived from the Brazilian plant Poincianella pyramidalis, in in vitro models of neuroinflammation. Cocultures of neurons/glial cells were exposed to lipopolysaccharide (LPS, 1 µg/mL) or interleukin (IL)-1β (10 ng/mL) for 24 h and treated with FAB (0.1 and 1 µM, 24 h). FAB displayed a significant neuroprotective effect, as measured by nitric oxide (NO) production, Fluoro-Jade B (FJ-B) staining, and immunocytochemistry (ICC) for the neuronal marker β-tubulin and the cell death marker caspase-3, preserving neuronal soma and increasing neurite outgrowth. FAB significantly decreased the LPS-induced microglial proliferation, identified by ICC for Iba-1/bromodeoxyuridine (BrdU) and CD68 (microglia M1 profile marker). In contrast, FAB had no apparent effect on astrocytes, as determined by ICC for glial fibrillary acidic protein (GFAP). Furthermore, FAB protected against the cytodestructive and proinflammatory effects of IL-1β, a key cytokine that is released by activated microglia and astrocytes, and ICC showed that combined treatment of FAB with α and β estrogen receptor antagonists did not affect NF-κB expression. In addition, qPCR analysis demonstrated that FAB decreased the expression of proinflammatory molecules TNF-α, IL-1β, and connexins CCL5 and CCL2, as well as increased the expression of the regulatory molecule IL-10. Together, these findings indicate that FAB has a significant neuroprotective and anti-inflammatory effect in vitro, which may be considered as an adjuvant for the treatment of neurodegenerative diseases
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