990 resultados para ENVIRONMENTAL CRISIS
Resumo:
The Urn Sohryngkew section of Meghalaya, NE India, located 800-1000 km from the Deccan volcanic province, is one of the most complete Cretaceous-Tertiary boundary (KTB) transitions worldwide with all defining and supporting criteria present: mass extinction of planktic foraminifera, first appearance of Danian species, delta(13)C shift, Ir anomaly (12 ppb) and KTB red layer. The geochemical signature of the KTB layer indicates not only an extraterrestrial signal (Ni and all Platinum Group Elements (PGEs)) of a second impact that postdates Chicxulub, but also a significant component resulting from condensed sedimentation (P), redox fluctuations (As, Co, Fe, Pb, Zn, and to a lesser extent Ni and Cu) and volcanism. From the late Maastrichtian C29r into the early Danian, a humid climate prevailed (kaolinite: 40-60%, detrital minerals: 50-80%). During the latest Maastrichtian, periodic acid rains (carbonate dissolution; CIA index: 70-80) associated with pulsed Deccan eruptions and strong continental weathering resulted in mesotrophic waters. The resulting super-stressed environmental conditions led to the demise of nearly all planktic foraminiferal species and blooms (>95%) of the disaster opportunist Guembelitria cretacea. These data reveal that detrimental marine conditions prevailed surrounding the Deccan volcanic province during the main phase of eruptions in C29r below the KTB. Ultimately these environmental conditions led to regionally early extinctions followed by global extinctions at the KTB. (C) 2011 Elsevier B.V. All rights reserved.
Resumo:
This paper presents general problems and approaches for the spatial data analysis using machine learning algorithms. Machine learning is a very powerful approach to adaptive data analysis, modelling and visualisation. The key feature of the machine learning algorithms is that they learn from empirical data and can be used in cases when the modelled environmental phenomena are hidden, nonlinear, noisy and highly variable in space and in time. Most of the machines learning algorithms are universal and adaptive modelling tools developed to solve basic problems of learning from data: classification/pattern recognition, regression/mapping and probability density modelling. In the present report some of the widely used machine learning algorithms, namely artificial neural networks (ANN) of different architectures and Support Vector Machines (SVM), are adapted to the problems of the analysis and modelling of geo-spatial data. Machine learning algorithms have an important advantage over traditional models of spatial statistics when problems are considered in a high dimensional geo-feature spaces, when the dimension of space exceeds 5. Such features are usually generated, for example, from digital elevation models, remote sensing images, etc. An important extension of models concerns considering of real space constrains like geomorphology, networks, and other natural structures. Recent developments in semi-supervised learning can improve modelling of environmental phenomena taking into account on geo-manifolds. An important part of the study deals with the analysis of relevant variables and models' inputs. This problem is approached by using different feature selection/feature extraction nonlinear tools. To demonstrate the application of machine learning algorithms several interesting case studies are considered: digital soil mapping using SVM, automatic mapping of soil and water system pollution using ANN; natural hazards risk analysis (avalanches, landslides), assessments of renewable resources (wind fields) with SVM and ANN models, etc. The dimensionality of spaces considered varies from 2 to more than 30. Figures 1, 2, 3 demonstrate some results of the studies and their outputs. Finally, the results of environmental mapping are discussed and compared with traditional models of geostatistics.
Resumo:
The incidence of neurodegenerative disease like Parkinson's disease and Alzheimer's disease (AD) increases dramatically with age; only a small percentage is directly related to familial forms. The etiology of the most abundant, sporadic forms is complex and multifactorial, involving both genetic and environmental factors. Several environmental pollutants have been associated with neurodegenerative disorders. The present article focuses on results obtained in experimental neurotoxicology studies that indicate a potential pathogenic role of lead and mercury in the development of neurodegenerative diseases. Both heavy metals have been shown to interfere with a multitude of intracellular targets, thereby contributing to several pathogenic processes typical of neurodegenerative disorders, including mitochondrial dysfunction, oxidative stress, deregulation of protein turnover, and brain inflammation. Exposure to heavy metals early in development can precondition the brain for developing a neurodegenerative disease later in life. Alternatively, heavy metals can exert their adverse effects through acute neurotoxicity or through slow accumulation during prolonged periods of life. The pro-oxidant effects of heavy metals can exacerbate the age-related increase in oxidative stress that is related to the decline of the antioxidant defense systems. Brain inflammatory reactions also generate oxidative stress. Chronic inflammation can contribute to the formation of the senile plaques that are typical for AD. In accord with this view, nonsteroidal anti-inflammatory drugs and antioxidants suppress early pathogenic processes leading to Alzheimer's disease, thus decreasing the risk of developing the disease. The effects of lead and mercury were also tested in aggregating brain-cell cultures of fetal rat telencephalon, a three-dimensional brain-cell culture system. The continuous application for 10 to 50 days of non-cytotoxic concentrations of heavy metals resulted in their accumulation in brain cells and the occurrence of delayed toxic effects. When applied at non-toxic concentrations, methylmercury, the most common environmental form of mercury, becomes neurotoxic under pro-oxidant conditions. Furthermore, lead and mercury induce glial cell reactivity, a hallmark of brain inflammation. Both mercury and lead increase the expression of the amyloid precursor protein; mercury also stimulates the formation of insoluble beta-amyloid, which plays a crucial role in the pathogenesis of AD and causes oxidative stress and neurotoxicity in vitro. Taken together, a considerable body of evidence suggests that the heavy metals lead and mercury contribute to the etiology of neurodegenerative diseases and emphasizes the importance of taking preventive measures in this regard.
Resumo:
The variation of abundances of intermediate snail hosts of Fasciola hepatica in Cuba (Fossaria cubensis and Pseudosuccinea columella) was studied during one year under natural conditions at five sampling sites in San Juan y Martinez municipality, Pinar del Rio province, Cuba. The effect of some environmental variables on the lymnaeid abundances was also studied. A canonical correspondence analysis showed that both species do not generally occur together in the same habitat and that most factors affect them in an opposite fashion, although both of them correlate positively through time to the diversity of the habitats. F. cubensis prefers the sites that are in or closer to the city whereas P. columella is more abundant in rural sites. Lymnaeid abundances are mainly affected by nitrite and nitrate concentrations as well as by the abundance of the thiarid Tarebia granifera. F. cubensis is more abundant in polluted habitats with low densities (or absence) of T. granifera whereas P. columella prefers cleaner habitats and can coexist with the thiarid, even at its higher densities. The implications of divergent preferences of the two lymnaeids for the control of fasciolosis are discussed.
Resumo:
Since the 1990s, and especially since the early 2000s, passionate controversies (Göle 2014) have emerged around the new visibility of Islam in the public sphere across Europe. These controversies, which crystallized in the headscarf debate, seem even more disturbing given that women who wear it are often young, urban and educated: that is to say, "modern" (Göle 1997, 2011). Indeed, these young women wearing the hijab seem to disrupt the narrative of Western modernity, including the decline in religious practice (Hervieu-Léger 2006) or the narration of the process of secularization in Europe. It is in the context of these controversies that Islam is built imaginatively as a "public problem" that has to be "solved" (Behloul 2012). Thus, this social construction of the Muslim other has nurtured an assessment of the failure of multiculturalism in some European countries and a process of convergence around a single model of civic integration in Europe (Behloul 2012, Joppke 2004, 2010).
Resumo:
This paper examines the distribution and infection of Biomphalaria glabrata with Schistosoma mansoni in all aquatic snail habitats in a rural area in the state of Minas Gerais, Brazil, in relation to physico/biotic and behavioral factors. Snail and environmental surveys were carried out semi-annually between July 2001 and November 2002 at 106 sites. Collected snails were examined in the laboratory for infection. B. glabrata densities were highest in overflow ponds, irrigation ponds, springs, canals and wells, and lowest in fishponds and water tanks. Snail densities were higher during the hot, rainy season except for streams and canals and were statistically associated with the presence of fish, pollution, and vegetation density. Tilapia fish and an unidentified Diptera larva were found to be predators of B. glabrata but ducks were not. Twenty-four of the 25 infected snails were collected in 2001(1.4% infection rate) and only one in 2002, after mass chemotherapy. The occurrence of B. glabrata in all 11 snail habitats both at and away from water contact sites studied indicates widespread risk of human infection in the study area. In spite of the strong association between B. glabrata and tilapia in fishponds we do not recommend its use in schistosomiasis control for ecological reasons and its relative inefficiency in streams and dams.
Resumo:
January 2010 saw the former Crisis Pregnancy Agencyâ?Ts integration into the Health Service Executive to become the HSE Crisis Pregnancy Programme. For most of 2010, the Programme was located in Children and Family Social Services Care Group in the Integrated Services Directorate and reported to Assistant National Director for Children and Family Social Services. The Programme commenced the process of forging links and relationships within the wider HSE and with services which support and add value to the work of the Programme. The Programme also made efforts to identify areas where it could share its expertise in the areas of crisis pregnancy and sexual health. In the latter part of 2010, the Programme was moved to Public Health with the aim of improving the alignment of the Programme to achieve better integration and create more opportunity to synchronise approaches with other related parts of the health service and to work more effectively at long term integration and planning 2012 - 2016.This resource was contributed by The National Documentation Centre on Drug Use.
Resumo:
Our objective is to evaluate the habitat preference of freshwater snails in relation to environmental factors and the presence of the competitor snail Melanoides tuberculatus. In the first phase, snails was collected at 12 sites. This sampling sites presented a degree of organic input. In the second phase 33 sampling sites were chosen, covering a variety of lotic and lentic environments. The snail species found at Guapimirim, state of Rio de Janeiro, displayed a marked habitat preference, specially in relation to the physical characteristics of each environment. Other limiting factors for snail distribution at the studied lotic environments were the water current velocity and the amount of organic matter, mainly to Physa marmorata, M. tuberculatus, and Biomphalaria tenagophila. The absence of interactions between M. tuberculatus and another snails could be associated to the distinct spatial distribution of those species and the instability of habitats. This later factor may favor the coexistence of M. tuberculatus with B. glabrata by reduction of population density. In areas of schistosomiasis transmission some habitat modification may add to the instability of the environment, which would make room for the coexistence of M. tuberculatus and Biomphalaria spp. In this way, some of the usual measures for the control of snail hosts would prevent the extinction of populations of Biomphalaria spp. by M. tuberculatus in particular habitats.
Resumo:
A report on Environmental Inequalities in the UK. Part of the Burden of disease. A clean and healthy environment is a vital component of public health. This is particularly so for children. They are more sensitive to most stressors during development and growth and receive relatively more exposure than adults due to behaviour patterns, lack of awareness, size and biological metabolisms.A study of the contribution of environmental pollutants to the incidence, prevalence, mortality and costs of four categories of paediatric disease in American children estimated total annual costs to be $54.9 billion comprising $43.4 billion for lead poisoning, $2.0 billion for asthma, $0.3 billion for childhood cancer, and $9.2 billion for neurobehavioral disorders; 2.8 % of total U.S. health care costs. As well as childhood conditions, some adult diseases, even those that emerge much later in life, e.g. hypertension, hyperlipidemia, insulin resistance, type 2 diabetes, ischemic heart disease, breast cancer and prostate cancer have some of their origins in utero and childhood. Childhood exposures to environmental health hazards may therefore constitute a source of inequity between generations .
Resumo:
This dissertation is a combination of three relatively independent chapters on the subject of corporate governance. Corporate governance is presently at the epicenter of the global financial crisis. The lack of regulation and the misalignment of objectives have greatly contributed to the major crisis we are now in. Most governance research has been conducted in the United States in a context of widely held corporations and great executive power. It does not reflect the variety of situations around the world and we question the validity of this model in other contexts. The aim of this dissertation is to look at other governance models, in particular the Swiss corporate governance not only from a practical point of view, but also from a multi-theoretical approach. Traditional corporate governance literature has focused on the Anglo-American model that mainly follows the agency theory (Jensen and Meckling, 1976) in a shareholder-manager context, and overlooked other approaches. We focus on three different aspects of corporate governance using three different theories. First, we look at the ownership type of various corporations, using the agency theory in a context where issues between shareholders predominate over the typical shareholder-manager relationship. Second, we explore the adoption process of several governance mechanisms that, due to changes in legislation, has taken place in Switzerland since 2002. We use the institutional theory (DiMaggio and Powell, 1983), in a context where the environmental pressures are particularly high. Finally, we spotlight the board of directors as a key element of the governance of publicly listed corporations. Particularly, we focus on the independence of the board of directors, using a combination of the agency and resource dependence theories (Pfeffer, 1972; Pfeffer and Salancik, 1978).
Resumo:
There has been growing concern that the quality of public services can be affected by the nature and scale of problems in deprived neighbourhoods and that poor services can contribute to a widening gap۪ between deprived and non-deprived neighbourhoods. There is also an increased emphasis within national policy on the quality of neighbourhood environments the so-called liveability۪ agenda. This report explores the challenges of delivering street scene۪ environmental services such as street sweeping and refuse collection in deprived and less deprived areas and examines the gap in environmental amenity between these different neighbourhoods. It also contributes to our understanding of the interplay between poor services and neighbourhood decline. The research involved a telephone survey of chief officers in local authority environmental service departments across the UK and detailed case studies of policy and practice in environmental service provision in four local authorities with significant levels of deprivation. Each case study involved work in three neighbourhoods within the authority two deprived and one less deprived as well as focus groups with residents and frontline environmental operatives, interviews with senior council staff and observation on the ground