859 resultados para human activities
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O solo é um recurso natural essencial para os seres humanos. Porém, atualmente, as atividades humanas estão provocando a degradação do solo principalmente através da aceleração dos processos erosivos. Os estudos sobre estes processos ajudam na compreensão, interpretação e conservação do solo. Assim, este trabalho pretende estudar e datar os processos erosivos em uma voçoroca localizada na Estação Experimental de Tupi (Piracicaba SP) mediante o uso da dendrogeomorfologia. A dendrogeomorfologia é uma ciência relativamente recente que relaciona os anéis de crescimento das árvores com processos geomorfológicos permitindo a reconstrução cronológica e ocorrência dos eventos. A relevância deste estudo é conhecer o potencial desta ciência em áreas tropicais já que atualmente este tipo de estudos são escassos nestas áreas. Esta técnica foi aplicada utilizando raízes expostas de espécies do gênero Pinus sp. A datação do processo erosivo baseou-se nas mudanças no padrão de crescimento das raízes, tais como: a largura do anel, crescimento excêntrico, porcentagem do lenho tardio e densidade do lenho ocorridas após a sua exposição pelo processo erosivo. Através do estudo destas alterações determinou-se o primeiro ano de exposição da raiz e se calculou a taxa de erosão anual. Os resultados mostraram que a voçoroca está formada pela integração de dois sistemas de diferentes origens que confluem em um degrau de erosão. A abertura das voçorocas está influenciada pela presença de processos de \"piping\" na área, os quais também afetam a morfologia das raízes quando enterradas. A taxa de erosão vertical, segundo o método de GÄRTNER (2007), atingem valores entre 17,0 e 36,5 mm/ano quantificando o processo de afundamento da voçoroca; e a taxa de erosão horizontal, segundo o método de MALIK (2008), valores de 0,70 e 1,45 m/ano caracterizando o avanço longitudinal da mesma. Estes resultados são elevados se comparados com resultados obtidos em climas temperados por outros autores e similares aos publicados por BOVI (2013) na mesma área de estudo. Finalmente, a dendrogeomorfologia se corrobora como uma ferramenta de grande potencial em áreas tropicais. Os dados e informações obtidos podem se traduzir num banco de dados dendrogeomorfológicos e contribuir à expansão desta ciência no Brasil e áreas de ambientes tropicais.
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O jacaré-de-papo (Caiman latirostris) é considerado um crocodiliano de médio porte que apresenta uma ampla distribuição latitudinal na América do Sul. Possivelmente a espécie possui a situação mais complexa entre os crocodilianos brasileiros quanto ao aspecto da conservação, basicamente porque suas populações encontram-se fragmentadas em grande parte de sua área de distribuição original e por utilizarem áreas com fortes atividades antrópicas. Embora a espécie possua aparentemente um processo adaptativo frente a estas pressões, um aspecto fisiológico pode ainda sofrer rápida alteração quando submetido a elas: o estado sanitário. Desta maneira, este estudo objetivou determinar o estado sanitário do maior predador aquático, utilizando duas áreas distintas no Estado de São Paulo, através da determinação dos perfis hematológicos e bioquímicos do sangue, além da caracterização da microbiota oral, servindo de modelo à conservação da espécie em ambientes alterados. No primeiro capítulo foram determinados o perfil hematológico e bioquímico do sangue utilizando-se 29 indivíduos (19 machos e 10 fêmeas) capturados em Angatuba e 11 indivíduos (2 machos, 4 fêmeas e 5 filhotes) capturados em Cubatão. Diferenças estatísticas significativas foram encontradas nos valores de creatinina na comparação entre fêmeas de ambas as áreas de estudo (p = 0,033) e nos valores de alanina aminotransferase (p = 0,003), hemácias (p = 0,034), hemoglobina (p = 0,049) e volume corpuscular médio (p = 0,027) quando da comparação entre sexos. No segundo capítulo determinou-se a microbiota oral destes animais através do isolamento, identificação e caracterização bacteriana, em conjunto com o teste de perfil de susceptibilidade aos antimicrobianos. Foram determinados 14 diferentes tipos de bactérias na área de Angatuba, sendo uma classificada como baciliforme aeróbio Gram-positivo, uma como bacilo Gram-negativo e 12 classificadas como Enterobactérias Gram-negativas. Na área de Cubatão foram isolados cinco tipos de bactérias, sendo quatro classificadas como Enterobactérias Gram-negativas e uma como baciliforme aeróbio Gram-positivo. Considerando que o uso de antimicrobianos é um processo primário no tratamento de animais e pessoas, principalmente nos casos que envolvam infecções provocadas pela interação homem x animais, para ambas as áreas de estudo, as quinolonas Enrofloxacina e Norfloxacina, além do aminoglicosídeo Gentamicina, foram os antimicrobianos que apresentaram os menores índices de resistência frente aos isolados testados.
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Os elementos potencialmente tóxicos (EPTs) estão presentes nos solos em concentrações dependentes do material de origem e das ações antrópicas. A adição de EPTs ao solo pelas atividades antrópicas pode ocasionar risco à saúde humana, já que estes elementos podem ser acumulados no organismo por meio do contato dérmico com o solo, da inalação de partículas em suspensão, de ingestão de solo e de alimentos contaminados. A contaminação dos alimentos ocorre pelo cultivo em áreas com alta biodisponibilidade de EPTs, e nessa condição ocorre absorção e translocação para a parte aérea, com possível acúmulo dos metais nas porções comestíveis, como raízes, frutos e grãos. A biodisponibilidade dos EPTs é regulada pelas características químicas dos elementos e por atributos do solo, como a CTC, o pH e a matéria orgânica (MO). Sintomas de toxicidade e alterações morfológicas e fisiológicas podem aparecer dependendo da absorção e da movimentação dos EPTs nas plantas. Objetivou-se neste trabalho avaliar o efeito da adição de bário (Ba), de cádmio (Cd), de cobre (Cu), de níquel (Ni) e de zinco (Zn) em amostras de um Neossolo Quartzarênico e um Latossolo Vermelho distrófico, sob duas condições de saturação por bases (30% e 50 ou 70%, dependendo da cultura), no cultivo de arroz (Oryza sativa), alface (Lactuca sativa), girassol (Helianthus annuus) e tomate (Solanum lycopersicum). Os EPTs nos solos foram extraídos com EPA 3051a, Água Régia, DTPA, Mehlich 1, Mehlich 3, HNO3 (0,43 mol L-1) e CaCl2 (0,01 mol L-1), e seus teores correlacionados com os presentes nas raízes, na parte aérea, nos frutos e com a quantidade acumulada pelas plantas. Os fatores de bioconcentração (FBC) e de transferência (FT) foram calculados para as culturas. O índice SPAD (Soil Plant Analysis Development - Chlorophyll Meter) foi determinado na fase vegetativa da alface, do arroz e do girassol, enquanto a atividade fotossintética foi determinada pelo IRGA (Infrared gas analyzer). Os maiores teores de EPTs foram observados nas plantas cultivadas no Neossolo. As quantidades de Cu, Ni e Zn acumuladas nas plantas apresentaram correlação positiva com os teores extraídos pelo EPA 3051a e pela Água Régia. Os teores extraídos com HNO3 (0,43 mol L-1) apresentaram elevada correlação positiva com os teores reativos extraídos com DTPA e com Mehlich 3, e também com as quantidades de EPTs acumuladas pelas plantas. Os FBCs foram mais altos nos solos com baixa CTC, baixos teores de MO e baixos valores de pH. O arroz apresentou a menor translocação de Cd do sistema radicular para os grãos. O Cu, o Ni e o Zn causaram alterações no desenvolvimento da alface e do girassol, e diminuíram a transpiração e a condutância estomática da alface. O arroz apresentou a menor absorção de EPTs e a maior tolerância ao Ba, ao Cd, ao Ni e ao Zn, no entanto, as plantas apresentaram maiores condutividade estomática e transpiração.
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Thesis (Master, Civil Engineering) -- Queen's University, 2016-06-01 00:03:02.939
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In recent decades wild boar have greatly increased in Europe due a combination of environmental and human factors. Because of a high reproduction rate, wild boar cause conflicts with human activities and in particularly agriculture. However, there are concerns also about environmental impact and in particular on ground nesting birds. Our study aim to evaluate the potential impact of wild boar on pheasants nests. Predation rates were compared between two areas with different wild boar abundance and between nests placed in fenced plots with no wild boar access (but accessible to other predators) and open plots in which the wild boar gains access. Predation rate by wild boar in the area with higher wild boar abundance was 61.5% whereas in the area with lower abundance was 16.0%. In plots with free access, wild boar predation was 34.2% whereas in exclusion plots we did not registered predation by wild boar. Moreover, wild boar resulted the main nest predator (total loss 22.8%). Our findings suggest that wild boar could have e strong impact on pheasant reproductive success.
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Central conceptual terms, such as ‘culture’, ‘environment’, ‘nature’ and ‘landscape’, are far from being neutral scientific objects. They are academic constructions which need to be understood in their emergence across their historic contexts. Morality is a cultural expression determined by social domination and historical context, which gives it a sectary character. We need a moral theory that can be universal, timeless and that is able to guide the individual conduct, science and political ideologies, without considering the man the zenith of Life. Life, with its biodiversity, is only the tip of a complex Cosmos evolution, but we don’t know if our species, born on planet Earth, are the final link in the Cosmos evolution. To answer all these questions, a new ethical perspective was born, a theory built upon the principles of meta-ethics and applicable to all human activities. Environmental ethics are supported by two principles – the critique against anthropocentrism and the critique against ethnocentrism, giving a universal answer to the macro moral problems of our era – environmental, social, economical and political crisis, war and weapons of mass destruction… And contributes towards rebuilding the human activities in all domains of individual and social life.
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Tese de doutoramento, Geologia (Hidrogeologia), Universidade de Lisboa, Faculdade de Ciências, 2016
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From June 1995 to August 2002 we assessed green turtle (Chelonia mydas) population structure and survival, and identified human impact, at Bahia de los Angeles, a large bay that was once the site of the greatest sea turtle harvest rates in the Gulf of California, Mexico. Turtles were captured live with entanglement nets and mortality was quantified through stranding surveys and flipper tag recoveries. A total of 14,820 netting hours (617.5 d) resulted in 255 captures of 200 green turtles. Straight-carapace length and mass ranged from 46.0-100.0 cm (mean = 74.3 +/- 0.7 cm) and 14.5-145.0 kg (mean = 61.5 +/- 1.7 kg), respectively. The size-frequency distribution remained stable during all years and among all capture locations. Anthropogenic-derived injuries ranging from missing flippers to boat propeller scars were present in 4% of captured turtles. Remains of 18 turtles were found at dumpsites, nine stranded turtles were encountered in the study area, and flipper tags from seven turtles were recovered. Survival was estimated at 0.58 for juveniles and 0.97 for adults using a joint live-recapture and dead-recovery model (Burnham model). Low survival among juveniles, declining annual catch per unit effort, and the presence of butchered carcasses indicated human activities continue to impact green turtles at this foraging area.
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Marine plants colonise several interconnected ecosystems in the Great Barrier Reef region including tidal wetlands, seagrass meadows and coral reefs. Water quality in some coastal areas is declining from human activities. Losses of mangrove and other tidal wetland communities are mostly the result of reclamation for coastal development of estuaries, e.g. for residential use, port infrastructure or marina development, and result in river bank destabilisation, deterioration of water clarity and loss of key coastal marine habitat. Coastal seagrass meadows are characterized by small ephemeral species. They are disturbed by increased turbidity after extreme flood events, but generally recover. There is no evidence of an overall seagrass decline or expansion. High nutrient and substrate availability and low grazing pressure on nearshore reefs have lead to changed benthic communities with high macroalgal abundance. Conservation and management of GBR macrophytes and their ecosystems is hampered by scarce ecological knowledge across macrophyte community types. (c) 2004 Elsevier Ltd. All rights reserved.
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Sediments, mosses and algae, collected from lake catchments of the Larsemann Hills, East Antarctica, were analysed to establish baseline levels of trace metals (Ag, As, Cd, Co, Cr, Cu, Ni, Sb, Pb, Se, V and Zn), and to quantify the extent of trace metal pollution in the area. Both impacted and non-impacted sites were included in the study. Four different leaching solutions (1 M MgCl2, 1 M CH3COONH4, 1 M NH4NO3, and 0.3 N HCl) were tested on the fine fraction (< 63 mu m) of the sediments to extract the mobile fraction of trace metals derived from human impact and from weathering of basement lithologies. Results of these tests indicate that dilute HCl partly dissolves primary minerals present in the sediment, thus leading to an overestimate of the mobile trace metal fraction. Concentrations of trace metals released using the other 3 procedures indicate negligible levels of anthropogenic contribution to the trace metal budget. Data derived from this study and a thorough characterisation of the site allowed the authors to define natural baseline levels of trace metals in sediments, mosses and algae, and their spatial variability across the area. The results show that, with a few notable exceptions, human activities at the research stations have contributed negligible levels (lower than natural variability) of trace metals to the Larsemann Hills ecosystem. This study further demonstrates that anthropogenic sources of trace metals can be correctly identified and quantified only if natural baselines, their variability, and processes controlling the mobility of trace metals in the ecosystem, have been fully characterised. (c) 2006 Elsevier Ltd. All rights reserved.
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This special issue of the Journal of the Operational Research Society is dedicated to papers on the related subjects of knowledge management and intellectual capital. These subjects continue to generate considerable interest amongst both practitioners and academics. This issue demonstrates that operational researchers have many contributions to offer to the area, especially by bringing multi-disciplinary, integrated and holistic perspectives. The papers included are both theoretical as well as practical, and include a number of case studies showing how knowledge management has been implemented in practice that may assist other organisations in their search for a better means of managing what is now recognised as a core organisational activity. It has been accepted by a growing number of organisations that the precise handling of information and knowledge is a significant factor in facilitating their success but that there is a challenge in how to implement a strategy and processes for this handling. It is here, in the particular area of knowledge process handling that we can see the contributions of operational researchers most clearly as is illustrated in the papers included in this journal edition. The issue comprises nine papers, contributed by authors based in eight different countries on five continents. Lind and Seigerroth describe an approach that they call team-based reconstruction, intended to help articulate knowledge in a particular organisational. context. They illustrate the use of this approach with three case studies, two in manufacturing and one in public sector health care. Different ways of carrying out reconstruction are analysed, and the benefits of team-based reconstruction are established. Edwards and Kidd, and Connell, Powell and Klein both concentrate on knowledge transfer. Edwards and Kidd discuss the issues involved in transferring knowledge across frontières (borders) of various kinds, from those borders within organisations to those between countries. They present two examples, one in distribution and the other in manufacturing. They conclude that trust and culture both play an important part in facilitating such transfers, that IT should be kept in a supporting role in knowledge management projects, and that a staged approach to this IT support may be the most effective. Connell, Powell and Klein consider the oft-quoted distinction between explicit and tacit knowledge, and argue that such a distinction is sometimes unhelpful. They suggest that knowledge should rather be regarded as a holistic systemic property. The consequences of this for knowledge transfer are examined, with a particular emphasis on what this might mean for the practice of OR Their view of OR in the context of knowledge management very much echoes Lind and Seigerroth's focus on knowledge for human action. This is an interesting convergence of views given that, broadly speaking, one set of authors comes from within the OR community, and the other from outside it. Hafeez and Abdelmeguid present the nearest to a 'hard' OR contribution of the papers in this special issue. In their paper they construct and use system dynamics models to investigate alternative ways in which an organisation might close a knowledge gap or skills gap. The methods they use have the potential to be generalised to any other quantifiable aspects of intellectual capital. The contribution by Revilla, Sarkis and Modrego is also at the 'hard' end of the spectrum. They evaluate the performance of public–private research collaborations in Spain, using an approach based on data envelopment analysis. They found that larger organisations tended to perform relatively better than smaller ones, even though the approach used takes into account scale effects. Perhaps more interesting was that many factors that might have been thought relevant, such as the organisation's existing knowledge base or how widely applicable the results of the project would be, had no significant effect on the performance. It may be that how well the partnership between the collaborators works (not a factor it was possible to take into account in this study) is more important than most other factors. Mak and Ramaprasad introduce the concept of a knowledge supply network. This builds on existing ideas of supply chain management, but also integrates the design chain and the marketing chain, to address all the intellectual property connected with the network as a whole. The authors regard the knowledge supply network as the natural focus for considering knowledge management issues. They propose seven criteria for evaluating knowledge supply network architecture, and illustrate their argument with an example from the electronics industry—integrated circuit design and fabrication. In the paper by Hasan and Crawford, their interest lies in the holistic approach to knowledge management. They demonstrate their argument—that there is no simple IT solution for organisational knowledge management efforts—through two case study investigations. These case studies, in Australian universities, are investigated through cultural historical activity theory, which focuses the study on the activities that are carried out by people in support of their interpretations of their role, the opportunities available and the organisation's purpose. Human activities, it is argued, are mediated by the available tools, including IT and IS and in this particular context, KMS. It is this argument that places the available technology into the knowledge activity process and permits the future design of KMS to be improved through the lessons learnt by studying these knowledge activity systems in practice. Wijnhoven concentrates on knowledge management at the operational level of the organisation. He is concerned with studying the transformation of certain inputs to outputs—the operations function—and the consequent realisation of organisational goals via the management of these operations. He argues that the inputs and outputs of this process in the context of knowledge management are different types of knowledge and names the operation method the knowledge logistics. The method of transformation he calls learning. This theoretical paper discusses the operational management of four types of knowledge objects—explicit understanding; information; skills; and norms and values; and shows how through the proposed framework learning can transfer these objects to clients in a logistical process without a major transformation in content. Millie Kwan continues this theme with a paper about process-oriented knowledge management. In her case study she discusses an implementation of knowledge management where the knowledge is centred around an organisational process and the mission, rationale and objectives of the process define the scope of the project. In her case they are concerned with the effective use of real estate (property and buildings) within a Fortune 100 company. In order to manage the knowledge about this property and the process by which the best 'deal' for internal customers and the overall company was reached, a KMS was devised. She argues that process knowledge is a source of core competence and thus needs to be strategically managed. Finally, you may also wish to read a related paper originally submitted for this Special Issue, 'Customer knowledge management' by Garcia-Murillo and Annabi, which was published in the August 2002 issue of the Journal of the Operational Research Society, 53(8), 875–884.
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Science and art are considered as two distinct areas in the spectrum of human activities. Many scientists are inspired by art and many artists embed science in their work. This paper presents a one-year experiment, which started with benchmark tests of a compiler, passed through dynamic systems based on complex numbers and ended as a scientific art exhibition. The paper demonstrates that it is possible to blend science and art in a mutually beneficial way. It also shows how science can inspire the creation of artistic works, as well as how these works can inspire further scientific research.
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There have been more and more words about climate change and global warming in the last few decades. But what do we really understand them? Is it logic that the climate change derived by human behaviour or is it an independent process of nature that occurs no matter how we try to stop it? Is the climate change a global warming or global cooling method? We know for sure that something is changing around us and we heard a million times that if we exhaust the resources of the Earth than we will cause permanent and irreversible damage. In the first part of this chapter we will see the facts. There will be a few different perspectives from a few different institutions publication about the methodology of measurement on climate change. In the second part of the chapter we shall distinguish how big part of the changes may be the results of the human activities, or is it even possible to distinguish what causes the climate change. In the last part of this chapter the IPCC’s scenario will be explained on the case if the process of the climate change can not be stopped, or if human kind does not do anything for mitigation.
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Over the past 200 years, an estimated 53% (about 47 million ha) of the original wetlands in the conterminous United States have been lost, mainly as a result of various human activities. Despite the importance of wetlands (particularly along the coast), and a longstanding federal policy framework meant to protect their integrity, the cumulative impact on these natural systems over large areas is poorly understood. We address this lack of research by mapping and conducting descriptive spatial analyses of federal wetland alteration permits (pursuant to section 404 of the Clean Water Act) across 85 watersheds in Florida and coastal Texas from 1991 to 2003. Results show that more than half of the permits issued in both states (60%) fell under the Nationwide permitting category. Permits issued in Texas were typically located outside of urban areas (78%) and outside 100-year floodplains (61%). More than half of permits issued in Florida were within urban areas (57%) and outside of 100-year floodplains (51%). The most affected wetlands types were estuarine in Texas (47%) and palustrine in Florida (55%). We expect that an additional outcome of this work will be an increased awareness of the cumulative depletion of wetlands and loss of ecological services in these urbanized areas, perhaps leading to increased conservation efforts.
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Body size is a fundamental structural characteristic of organisms, determining critical life history and physiological traits, and influencing population dynamics, community structure, and ecosystem function. For my dissertation, I focused on effects of body size on habitat use and diet of important coastal fish predators, as well as their influence on faunal communities in Bahamian wetlands. First, using acoustic telemetry and stable isotope analysis, I identified high variability in movement patterns and habitat use among individuals within a gray snapper (Lutjanus griseus) and schoolmaster snapper (L. apodus) population. This intrapopulation variation was not explained by body size, but by individual behavior in habitat use. Isotope values differed between individuals that moved further distances and individuals that stayed close to their home sites, suggesting movement differences were related to specific patterns of foraging behavior. Subsequently, while investigating diet of schoolmaster snapper over a two-year period using stomach content and stable isotope analyses, I also found intrapopulation diet variation, mostly explained by differences in size class, individual behavior and temporal variability. I then developed a hypothesis-testing framework examining intrapopulation niche variation between size classes using stable isotopes. This framework can serve as baseline to categorize taxonomic or functional groupings into specific niche shift scenarios, as well as to help elucidate underlying mechanisms causing niche shifts in certain size classes. Finally, I examined the effect of different-sized fish predators on epifaunal community structure in shallow seagrass beds using exclusion experiments at two spatial scales. Overall, I found that predator effects were rather weak, with predator size and spatial scale having no impact on the community. Yet, I also found some evidence of strong interactions on particular common snapper prey. As Bahamian wetlands are increasingly threatened by human activities (e.g., overexploitation, habitat degradation), an enhanced knowledge of the ecology of organisms inhabiting these systems is crucial for developing appropriate conservation and management strategies. My dissertation research contributed to this effort by providing critical information about the resource use of important Bahamian fish predators, as well as their effect on faunal seagrass communities.