5,223 research outputs found
Fire patterns in central semiarid Argentina.
Wildfires can cause severe impacts on the terrestrial ecosystems depending on their frequency and behavior. We studied the environmental factors influencing the spatial and temporal distribution of fires, their size and duration in the central semiarid Argentina. We identified fires using MODIS satellite data and we analyzed their association with climate and land cover/use patterns. Spatial and temporal fire patterns varied between eastern, central and western regions according to the presence of agriculture, shrublands and water deficits, respectively. The frequency and behavior of fires also varied temporally with water conditions. Years with low effective precipitations were characterized by an important hotspot density and fire number, as well as the months preceded by two months with low effective precipitation (r 2: 0.42; p < 0.0001). We observed a spatial delay of fires in a northeast-southwest sense, related to the delay of the spring beginning (r 2: 0.7594; p < 0.0001). The mean fire sizes and duration varied significantly among vegetation types (F: 10.76, p < 0.0001 and F: 3.703, p < 0.01). Fires were bigger in shrublands and longer in shrublands or forests regarding agricultural areas or degraded areas (F: 16.0, p < 0.0001). The results obtained would be useful to prevent/control fires and to preserve natural resources and human communities.Fil: Fischer, M. A.. Instituto Nacional de TecnologĂa Agropecuaria. Centro de InvestigaciĂłn de Recursos Naturales. Instituto de Clima y Agua; ArgentinaFil: Di Bella, Carlos Marcelo. Instituto Nacional de TecnologĂa Agropecuaria. Centro de InvestigaciĂłn de Recursos Naturales. Instituto de Clima y Agua; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: JobbĂĄgy, Esteban Gabriel. Universidad Nacional de San Luis; Argentin
Impact of mediterranean diet on chronic non-communicable diseases and longevity
The average life expectancy of the world population has increased remarkably in the past 150 years and it is still increasing. A long life is a dream of humans since the beginning of time but also a dream is to live it in good physical and mental condition. Nutrition research has focused on recent decades more on food combination patterns than on individual foods/nutrients due to the possible synergistic/antagonistic effects of the components in a dietary model. Various dietary patterns have been associated with health benefits, but the largest body of evidence in the literature is attributable to the traditional dietary habits and lifestyle followed by populations from the Mediterranean region. After the Seven Countries Study, many prospective observational studies and trials in diverse populations reinforced the beneficial effects associated with a higher adherence to the Mediterranean diet in reference to the prevention/management of age-associated non-communicable diseases, such as cardiovascular and metabolic diseases, neurodegenerative diseases, cancer, depression, respiratory diseases, and fragility fractures. In addition, the Mediterranean diet is ecologically sustainable. Therefore, this immaterial world heritage constitutes a healthy way of eating and living respecting the environment
Localization of antimicrobial peptides in the tunic of Ciona intestinalis ( Ascidiacea, Tunicata) and their involvement in local inflammatory-like reactions
Tunicates comprising a wide variety of different species synthesize antimicrobial peptides as important
effector molecules of the innate immune system. Recently, two putative gene families coding for
antimicrobial peptides were identified in the expressed sequence tag database of the tunicate Ciona
intestinalis. Two synthetic peptides representing the cationic core region of one member of each of the
families displayed potent antibacterial and antifungal activities. Moreover, the natural peptides were
demonstrated to be synthesized and stored in distinct hemocyte types. Here, we investigated the
presence of these natural peptides, namely Ci-MAM-A and Ci-PAP-A, in the tunic of C. intestinalis
considering that the ascidian tunic is a body surface barrier exposed to constant microbial assault.
Furthermore, as the tunic may represent a major route of entry for pathogen invasion after its damage
we monitored the location of these peptides upon a local inflammatory-like reaction induced by
injection of foreign cells. Using immunocytochemistry and electron microscopy both peptides were
localized to the tunic and were massively present in granulocytes of inflamed tissue. Conclusively,
antimicrobial peptides may constitute a chemical barrier within the tunic of urochordates
Characterization and treatment proposals of shipboard slop wastewater contaminated by hydrocarbons
Shipboard slop wastewaters are produced by the activity of washing of oil tankers with seawater, and are characterized by high salinity and hydrocarbons. In this context, harbor authorities are forced to respect the international regulation IMO-MARPOL 73/78 and they must treat slop wastewater before discharging to the sea. This study compared data from three stand-alone treatments working with the same real slop wastewater: (1) a chemical treatment of coagulation-flocculation with aluminum sulphate as coagulant and an anionic flocculant (A57), (2) a physical treatment of adsorption on granular activated carbon (GAC), (3) two biological treatments represented by a membrane bioreactor (MBR) and a moving bed biofilm reactor (MB-MBR). GAC treatment registered the highest removal efficiency of total petroleum hydrocarbons (ηTPH) next to 85%, since the activated carbon had excellent adsorption properties towards organic substances. The coagulation-flocculation treatment reported the lowest ηTPH â 57% due to the presence of emulsified hydrocarbons that were not affected by the coagulant and flocculant action, so remaining in liquid phase. ηTPH â 70% obtained with MB-MBR fed with 100% volume of slop, suggested biomass acclimation to salinity and hydrocarbons. Based on the results of each process, three main treatment chains are proposed depending on the hydrocarbons load of the real slop wastewater
Exploiting Slow Dynamics Effects for Damage Detection in Concrete
Nonlinear ultrasonic techniques have been developed over the last decades to detect the presence of damage in materials of interest in the field of civil engineering, such as concrete or mortar. The dependence on the strain amplitude of measurable quantities, such as wave velocity, damping factor, resonance frequency, etc. is normally considered a qualitative indicator of the presence of defects at the microstructural level. The experimental approaches proposed have the advantage of being sensitive to small variations in the sample microstructure and are therefore more adapted to detect the presence of small cracks or damaged areas with respect to traditional linear ultrasonic techniques. However, nonlinear methods are difficult to implement, since they usually require a calibrated experimental set-up which also behaves linearly at high amplitudes of excitation. The slow dynamics features, typical of the hysteresis generated by damage, have been given much less attention as a tool for damage detection even though their quantification is often less demanding in terms of an experimental set-up. Here, we provide the first evidence of how recovery, which is part of the slow dynamics process, is sensitive to the presence of damage in concrete samples and thus could be considered as an easy-to-measure nonlinear indicator for Structural Health Monitoring purposes
Quality controls for cell cultures: identification of interspecies cross-contamination by PCR-RFLP analysis of the cytochrome b gene
Cross-contaminations of a cell line with cells of different species represent a potential risk in laboratories handling human and animal cells. Therefore, it is necessary to control such contaminations. Tests based on mitochondrial DNA (mtDNA) are used in forensic analysis, phylogenetic studies and in food authentication. However, the use of mtDNA in quality controls of cell cultures is recent. Mitochondrial sequence differences of closely related animal species are five- to tenfold higher than those of nuclear genes. On the contrary, intraspecies variation in mitochondrial sequences is low in most animal species. Moreover, each cell contains 100â10.000 mitochondrial genomes. The amount of mtDNA is greater than nuclear DNA, so that mtDNA can be analyzed also from small or partially degraded samples. In the present study, a method based on a PCR-Restriction Fragment Length Polymorphism (RFLP) analysis of the mitochondrial cytochrome b gene was used (2). This gene has some stable sequences which are recognized from universal primers and some variable sequences used for animal species identification by PCR-RFLP method
Exosomes from metastatic cancer cells transfer amoeboid phenotype to non-metastatic cells and increase endothelial permeability: their emerging role in tumor heterogeneity
The goal of this study was to understand if exosomes derived from high-metastatic cells may influence the behavior of less aggressive cancer cells and the properties of the endothelium. We found that metastatic colon cancer cells are able to transfer their amoeboid phenotype to isogenic primary cancer cells through exosomes, and that this morphological transition is associated with the acquisition of a more aggressive behavior. Moreover, exosomes from the metastatic line (SW620Exos) exhibited higher ability to cause endothelial hyperpermeability than exosomes from the non metastatic line (SW480Exos). SWATH-based quantitative proteomic analysis highlighted that SW620Exos are significantly enriched in cytoskeletal-associated proteins including proteins activating the RhoA/ROCK pathway, known to induce amoeboid properties and destabilization of endothelial junctions. In particular, thrombin was identified as a key mediator of the effects induced by SW620Exos in target cells, in which we also found a significant increase of RhoA activity. Overall, our results demonstrate that in a heterogeneous context exosomes released by aggressive sub-clones can contribute to accelerate tumor progression by spreading malignant properties that affect both the tumor cell plasticity and the endothelial cell behavior
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