1,424 research outputs found

    Introduction

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    Lineamientos de gestión ambiental para la industria ladrillera del Municipio de Itaguí-Antioquia

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    La actividad ladrillera en el municipio de Itagüí, esta localizada dentro de la cuenca de la quebrada la Jabalcona (afluente del río Medellín), allí se encuentran dos tipos de empresas las artesanales y tecnificadas, cada una de ellas se diferencian técnica, económica y socialmente, pero generan impactos ambientales negativos al ambiente. Una gestión ambiental adecuada esta directamente relacionada con tres sectores, ellos son las instituciones (las autoridades ambientales, las universidades y la Asociación de Ladrilleras Unidas de Antioquia S.A LUNSA), la comunidad y las empresas, éstos deben tener lineamientos de gestión ambiental claros para cada labor que genera impactos ambientales negativos. En este articulo se presentan los lineamientos de gestión ambiental para la industria ladrillera del Municipio de Itagüí con base en el Plan de ordenamiento Territorial (2000-2009) y el Plan de Desarrollo Municipal (2001-2003) como un aporte para el Ordenamiento Ambiental del Municipio.The brickmaker activity in the municipality of Itagüí, this located within the Jabalconas river basin (river Medellin's affluent), this is the two types, aftisan and technified, each one of them are technical, economic and socially differents, but they gerlerate negative environmental impacts to the atmosphere. An environmental management adapted is directly related with three sectors, they are the institutions (the environmental authorities, the universities and Association of Brickmarker United of Antioquia A.S - LUNSA), the community and the companies, they must have clear environmental management guidelines for each work that generates environmental impacts negative. This paper, shows environmental management guidelines for the brickmaker industry in the municipality of Itagüí, with base in the Territorial Ordaining Plan (2000-2009) y the Development Plan Municipal (2001-2003), like a contribution to the Environmental Ordaining of the municipality

    Antibodies to Toxoplasma gondii and Neospora caninum in Captive Neotropical and Exotic Wild Canids and Felids

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    Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)This study was designed to detect antibodies to Toxoplasma gondii and Neospora caninum in wild captive carnivores maintained in Brazilian zoos. Blood samples were collected from 142 Brazilian wild felids and 19 exotic felids in zoos, and 3 European wolves (Canis lupus) and 94 Brazilian wild canids maintained in captivity in Brazilian zoos of Sao Paulo, Mato Grosso states and Federal District. One hundred and two (63.4%) and 70 (50.3%) of the 161 wild felids tested were seropositive for T gondii and N. caninum by indirect immunofluorescent assay test (IFAT), respectively. Among sampled wild canids, 49 (50.5%) and 40 (41.2%) animals were seropositive for T. gondii and N. caninum antigens by IFAT, respectively. To our knowledge, this is the first serological detection of antibodies to N. caninum in Brazilian wild captive felids and bush dogs (Speothos venaticus (Lund)).96510071009Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Instituto Brasileiro do Meio Ambiente e dos Recursos Naturais Renovaveis (IBAMA) [S02027.002943/2005, 15901-1]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP [07/59889-6, 08/55570-8]Instituto Brasileiro do Meio Ambiente e dos Recursos Naturais Renovaveis (IBAMA) [S02027.002943/2005, 15901-1

    Caveolin-1 protects B6129 mice against Helicobacter pylori gastritis.

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    Caveolin-1 (Cav1) is a scaffold protein and pathogen receptor in the mucosa of the gastrointestinal tract. Chronic infection of gastric epithelial cells by Helicobacter pylori (H. pylori) is a major risk factor for human gastric cancer (GC) where Cav1 is frequently down-regulated. However, the function of Cav1 in H. pylori infection and pathogenesis of GC remained unknown. We show here that Cav1-deficient mice, infected for 11 months with the CagA-delivery deficient H. pylori strain SS1, developed more severe gastritis and tissue damage, including loss of parietal cells and foveolar hyperplasia, and displayed lower colonisation of the gastric mucosa than wild-type B6129 littermates. Cav1-null mice showed enhanced infiltration of macrophages and B-cells and secretion of chemokines (RANTES) but had reduced levels of CD25+ regulatory T-cells. Cav1-deficient human GC cells (AGS), infected with the CagA-delivery proficient H. pylori strain G27, were more sensitive to CagA-related cytoskeletal stress morphologies ("humming bird") compared to AGS cells stably transfected with Cav1 (AGS/Cav1). Infection of AGS/Cav1 cells triggered the recruitment of p120 RhoGTPase-activating protein/deleted in liver cancer-1 (p120RhoGAP/DLC1) to Cav1 and counteracted CagA-induced cytoskeletal rearrangements. In human GC cell lines (MKN45, N87) and mouse stomach tissue, H. pylori down-regulated endogenous expression of Cav1 independently of CagA. Mechanistically, H. pylori activated sterol-responsive element-binding protein-1 (SREBP1) to repress transcription of the human Cav1 gene from sterol-responsive elements (SREs) in the proximal Cav1 promoter. These data suggested a protective role of Cav1 against H. pylori-induced inflammation and tissue damage. We propose that H. pylori exploits down-regulation of Cav1 to subvert the host's immune response and to promote signalling of its virulence factors in host cells

    A general piecewise multi-state survival model: Application to breast cancer

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    Multi-state models are considered in the field of survival analysis for modelling illnesses that evolve through several stages over time. Multi-state models can be developed by applying several techniques, such as non-parametric, semi-parametric and stochastic processes, particularly Markov processes. When the development of an illness is being analysed, its progression is tracked periodically. Medical reviews take place at discrete times, and a panel data analysis can be formed. In this paper, a discrete-time piecewise non-homogeneous Markov process is constructed for modelling and analysing a multi-state illness with a general number of states. The model is built, and relevant measures, such as survival function, transition probabilities, mean total times spent in a group of states and the conditional probability of state change, are determined. A likelihood function is built to estimate the parameters and the general number of cut-points included in the model. Time-dependent covariates are introduced, the results are obtained in a matrix algebraic form and the algorithms are shown. The model is applied to analyse the behaviour of breast cancer. A study of the relapse and survival times of 300 breast cancer patients who have undergone mastectomy is developed. The results of this paper are implemented computationally with MATLAB and R.Ministerio de Economía y Competitividad FQM-307European Regional Development Fund (ERDF) MTM2017-88708-PUniversity of Milano-Bicocca 2014-ATE-022

    Multi-wavelength analysis of high energy electrons in solar flares: a case study of August 20, 2002 flare

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    A multi-wavelength spatial and temporal analysis of solar high energy electrons is conducted using the August 20, 2002 flare of an unusually flat (gamma=1.8) hard X-ray spectrum. The flare is studied using RHESSI, Halpha, radio, TRACE, and MDI observations with advanced methods and techniques never previously applied in the solar flare context. A new method to account for X-ray Compton backscattering in the photosphere (photospheric albedo) has been used to deduce the primary X-ray flare spectra. The mean electron flux distribution has been analysed using both forward fitting and model independent inversion methods of spectral analysis. We show that the contribution of the photospheric albedo to the photon spectrum modifies the calculated mean electron flux distribution, mainly at energies below 100 keV. The positions of the Halpha emission and hard X-ray sources with respect to the current-free extrapolation of the MDI photospheric magnetic field and the characteristics of the radio emission provide evidence of the closed geometry of the magnetic field structure and the flare process in low altitude magnetic loops. In agreement with the predictions of some solar flare models, the hard X-ray sources are located on the external edges of the Halpha emission and show chromospheric plasma heated by the non-thermal electrons. The fast changes of Halpha intensities are located not only inside the hard X-ray sources, as expected if they are the signatures of the chromospheric response to the electron bombardment, but also away from them.Comment: 26 pages, 9 figures, accepted to Solar Physic

    Probing host pathogen cross-talk by transcriptional profiling of both Mycobacterium tuberculosis and infected human dendritic cells and macrophages

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    This study provides the proof of principle that probing the host and the microbe transcriptomes simultaneously is a valuable means to accessing unique information on host pathogen interactions. Our results also underline the extraordinary plasticity of host cell and pathogen responses to infection, and provide a solid framework to further understand the complex mechanisms involved in immunity to M. tuberculosis and in mycobacterial adaptation to different intracellular environments

    The macroecology of phylogenetically structured hummingbird-plant networks

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    Aim To investigate the association between species richness, species' phylogenetic signal, insularity and historical and current climate with hummingbird-plant network structure. Location 54 communities along a c. 10,000 kilometer latitudinal gradient across the Americas (39ºN - 32ºS), ranging from sea level to c. 3700 m asl, located on the mainland and on islands, and covering a wide range of climate regimes. Methods We measured null-modeled corrected complementary specialization and bipartite modularity (compartmentalization) in networks of quantitative interactions between hummingbird and plant species. Using an ordinary least squares multi-model approach, we examined the influence of species richness, phylogenetic signal, insularity, and current and historical climate conditions on network structure. Results Phylogenetically-related species, especially plants, showed a tendency to interact with a similar array of partners. The spatial variation in network structure exhibited a constant association with species' phylogeny (R2=0.18-0.19). Species richness and environmental factors showed the strongest associations with network structure (R2=0.20-0.44; R2138 =0.32-0.45, respectively). Specifically, higher levels of complementary specialization and modularity were associated to species-rich communities and communities in which closely-related hummingbirds visited distinct sets of flowering species. On the mainland, warmer temperatures and higher historical temperature stability associated to higher levels of complementary specialization. Main conclusions Previous macroecological studies of interaction networks have highlighted the importance of environment and species richness in determining network structure. Here, for the first time, we report an association between species phylogenetic signal and network structure at macroecological scale. Specifically, null model corrected complementary specialization and modularity exhibited a positive association with species richness and a negative association with hummingbird phylogenetic signal, indicating that both high richness and high inter-specific competition among closely-related 150 hummingbirds exhibit important relationships with specialization in hummingbird-plant networks. Our results document how species richness, phylogenetic signal and climate associate with network structure in complex ways at macroecological scale
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