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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
211

Environment driven consumer EC model incorporating complexities of consumer body dynamics

Ali, S.M., Khan, B., Mokryani, Geev, Mehmood, C.A., Jawad, M., Farid, U. 18 February 2019 (has links)
Yes / Energy consumption (EC) of consumers primarily depends on comfort level (CL) affirmed by brain sensations of the central nervous system. Environmental parameters such as surroundings, relative humidity, air temperature, solar irradiance, air pressure, and cloud cover directly influence consumer body temperature that in return affect blood dynamics perturbing brain comfort sensations. This CL (either in summer, winter, autumn, or spring season) is a function of external environment and internal body variations that force a consumer toward EC. To develop a new concept of consumer's EC, first the authors described environment parameters in detail with relation to surroundings and EC. Considering this, they tabulated a generic relation of consumer's CL with EC and environment temperature. Second, to build an inter-related bond between the environmental effects on consumer body dynamics, they analysed theoretically and mathematically above mutual relations between medical and environmental sciences. Finally, they present their conceptual EC model based on a closed-loop feedback system. This model is a complex non-linear adaptive system with environmental and surrounding parameters as input to the system resulting in an optimised EC, considering consumer CL as a key parameter for the system.
212

African-American Male Perceptions on Public Schooling after Discipline: A Contextual Portrait from the Inner City

Smith, Kevin William, Jr. 27 April 2019 (has links) (PDF)
Literature shows that one of the major issues affecting the achievement of inner-city African- American male students in public-schools is the ineffectiveness of disciplinary procedures. These studies have shown a direct positive relationship between student behavioral problems and academic failure. This study was an attempt at answering Noguera’s (2008) call for understanding more fully how African-American males come to perceive schooling, in particular their discipline experiences, and how environmental and cultural forces impact this perception of their behavior and performance in school. This was a qualitative study that heard the stories of inner-city African-American male students who were pushed out of public-schools through disciplinary measures. This study was based on racial components that fit directly into the structure of Critical Race Theory (CRT). The qualitative research method of portraiture was used to answer this study’s research question because it was relative to the problems that African- American male students face in their inner-city schooling experiences. The participants in this study were at least eighteen years old, African American, and pushed out of an inner-city public high school based on disciplinary consequences. Each participant shared environmental, cultural, and schooling experiences through a series of three interviews. The study found that environmental and cultural forces had a negative affect on the ways that these African-American males perceived their experiences in public-schools. The study concluded that these young men found success in private-continuation-schools, and that educators and policy makers should consider implementing the practices of these alternative schools in U.S. public-schools.
213

Floristic composition and environmental determinants of roadside vegetation in North England.

Akbar, K.F., Hale, William H.G., Headley, Alistair D.D. 2011 January 1918 (has links)
No / The roadside vegetation in some counties of north England (north and west Yorkshire) was studied to determine the community structure according to the British National Vegetation Classification (NVC) and main environmental factors influencing its composition. The data from Phytosociological survey (699 quadrats) and from the physico-chemical analyses of 233 soil samples from 35 sites were obtained. Both the classification (TWINSPAN & MATCH) and ordination programs (Canonical Correspondence Analysis) were used. The roadside vegetation is mainly dominated by few grasses (Arrhenatherum elatius, Festuca rubra, Dactylis glomerata, Lolium perenne, Poa trivialis, Elymus repens, Holcus lanatus) and their associated herbs (Cirsium arvense, Heracleum sphondylium, Urtica dioica). Five NVC Mesotrophic grassland communities (Arrhenatheretum elatioris community MG1, Lolium perenne-Cynosurus cristatus grassland MG6, Lolium perenne leys MG7, Holcus lanatus- Deschampsia cespitosa grassland MG9, Festuca rubra-Agrostis stolonifera-Potentilla anserina grassland MG11) and one Upland Festuca ovina- Agrostis capillaris-Galium saxatile grassland, U4 were identified which in general, exhibited good fit with the typical NVC units. Altitude, pH, potassium, sodium and road age were found to be the main variables affecting the roadside vegetation. By relating the floristic composition with ecological characteristics of the roadside verges, three kinds of pattern of variation are observed. The first pattern is related to regional or geographical characteristics and the second pattern of variation exists across the width of the road verges showing a zonal pattern of plant distribution. The third scale of pattern is active at the local level including micro-environmental conditions, e.g., local edaphic variables.
214

Dinâmica populacional e avaliação do estoque do camarão rosa (Farfantepenaeus subtilis Pérez-Farfante 1967) na plataforma continental amazônica brasileira / Population dynamics and stock assessment of the brown shrimp, Farfantepenaeus subtilis, (Pérez-Farfante 1967) in the Amazon continental shelf

Aragão, José Augusto Negreiros 12 September 2012 (has links)
O camarão rosa (Farfantepenaeus subtilis) explotado pela pesca industrial na plataforma continental amazônica brasileira possui um ciclo de vida curto, mas complexo, habitando áreas oceânicas, mais ao norte da área de ocorrência, na fase adulta e larval, e áreas estuarinas e lagunares na fase de pós-larva e juvenil. O período de maior intensidade de reprodução se estende de maio a setembro e logo após a reprodução as larvas eclodem e iniciam sua migração para áreas costeiras, passando por diversas fases, onde se assentam e residem principalmente entre junho e outubro. A partir de setembro até janeiro do ano seguinte é maior a intensidade de recrutamento de juvenis às áreas oceânicas, onde passam a amadurecer e, a partir de dezembro, começam a ser capturados pela pesca industrial. A maior abundância da população adulta em termos de biomassa vai de março a agosto quando também se verificam as maiores capturas. As fêmeas crescem mais que os machos e estão presentes sempre em maior proporção nas capturas (61%). Os comprimentos assintóticos foram estimados em 231 mm ( k = 1,6 \'ano POT.-1\') e 205 mm (k = 0,94 \'ano POT.-1\'), para fêmeas e machos respectivamente. A população apresenta taxa de mortalidade natural relativamente elevada, 2,53 \'ano POT.-1\' para fêmeas e 1,83 \'ano POT.-1\' para machos, sendo observadas acentuadas flutuações de recrutamento e abundância, com evidências de que são fortemente governadas pelas condições ambientais. O estoque vem sendo explotado em níveis moderados nos anos recentes (E = 0,45), embora tenha sofrido elevadas taxas de explotação na década de 80, o que levou a uma redução do tamanho da população. O rendimento máximo sustentável, considerado uma média de longo prazo, foi estimado em 4.032 toneladas de cauda por ano, para um esforço de pesca de 19.370 dias de mar. Nos últimos anos, se observa uma tendência de recuperação da biomassa populacional, mas com as oscilações anuais características da espécie. A vazão do rio Amazonas é o fator ambiental que governa com mais intensidade as condições do ambiente costeiro na região e verificou-se que suas flutuações estão correlacionadas a alterações na abundância da população da espécie. Postula-se que o aporte e sobrevivência das larvas e pós-larvas no ambiente costeiro seja influenciada pela intensidade da vazão do rio. O período em que se assentam nos berçários na zona costeira coincide com a estação de vazante do rio, sendo a sobrevivência favorecida por vazões abaixo da média e vice-versa. Portanto, medidas de ordenamento voltadas para o uso sustentável do recurso devem estar associadas ao conhecimento das condições ambientais nesta fase, bem como a estudos sobre a abundância de pós-larvas e juvenis na faixa costeira. / The brown shrimp (Farfantepenaeus subtilis) exploited by the industrial fishery on the continental shelf of the Brazilian Amazon has a short but complex life cyele, inhabiting oceanic areas, at the north of the area of occurrence, during the adult and larval stages, and estuarine areas and lagoons in post-larval and juvenile. The period of highest intensity of reproduction extends from May to September and soon after the hatch, the larvae start their migration to coastal areas, passing through several stages, where they settle and remain resident between June and October. From September to January of the following year the intensity of recruitment to ocean areas is higher, and once there they start to mature and are caught by the industrial fishery from December on. The highest abundance of the adult population in terms of biomass is observed from March to August when the largest catches also occur. Females grow larger than males and are always present in greater proportion in catches (61%). The asymptotic lengths were estimated at 231 mm (k = 1.6 \'year POT.-1\') and 205 mm (k = 0.94 \'year POT.-1\') for females and males respectively. The population has a natural mortality rate relatively high, 2.53 \'year POT.-1\' for females and 1.83 \'years POT.-1\' for males, and pronounced fluctuations in recruitment and abundance are observed, with evidence of being strongly governed by environmental conditions. The stock has been exploited at moderate levels in recent years (E = 0.45), although it has suffered high rates of exploitation in the 80\'s, which led to a reduction in population size. The maximum sustainable yield, considered a long-term average, was estimated at 4,032 ton of tail per year for a fishing effort of 19,370 days at sea. In recent years, it is observed a tendency of recovering of the population biomass, but annual fluctuations are characteristics of the species. The flow of the Amazon River is the main environmental facto r that governs the conditions of the coastal environment in the region and it was found that it is correlated with the fluctuatícn of the brown shrimp population abundance. It is postulated that the uptake and survival of larvae and post larvae in the coastal environment is lnfluenced by the intensity of river flow, The period during which they settle at the nurseries in the coastal zone coincides with the dry season and their survival is favored when the flow of the river is below the average, and vice versa. Therefore, management measures aimed at sustainable use of the resource must be associated with the knowledge of environmental conditions during this phase, as well as studies on the abundance of post-larvae and juveniles in the coastal zone.
215

Avaliação da influência de fatores ambientais sobre o diagnóstico de artrite idiopática juvenil em crianças e adolescentes / Evaluation of the influence of environmental factors on the juvenile idiopathic arthritis in children and adolescents

França, Camila Maria Paiva 14 March 2017 (has links)
A artrite idiopática juvenil (AIJ) constitui um grupo heterogêneo de doenças que se caracteriza por inflamação crônica em uma ou mais articulações, com diagnóstico em menores de 16 anos de idade. A poluição atmosférica tem sido responsabilizada pelo aumento da morbidade e mortalidade em doenças cardiorrespiratórias, mas poucos estudos avaliaram os efeitos da exposição prolongada sobre doenças inflamatórias crônicas. Alguns estudos demonstram associação entre fumo e início da doença reumatológica em adultos e outros mostram associação de mães fumantes durante a gravidez com desenvolvimento de AIJ nos filhos. Entretanto, existem poucos estudos na literatura avaliando a exposição à poluição do ar e AIJ. Objetivo: avaliar a influência de poluentes ambientais inalatórios como fatores de risco no desenvolvimento da AIJ em pacientes residentes na Região Metropolitana de São Paulo, acompanhados em um serviço terciário de Reumatologia Pediátrica. Metodologia: Este foi um estudo retrospectivo, do tipo caso-controle, que incluiu 66 pacientes com AIJ e 124 controles saudáveis, semelhantes em idade e gênero, residentes na Região Metropolitana de São Paulo, desde a gestação até o diagnóstico da doença. Um questionário estruturado e com alto índice de confiabilidade (índice kappa para teste-reteste 0,80) avaliou dados demográficos, fatores relacionados à gestação e ao período perinatal, exposição ocupacional materna durante a gravidez a partículas inaláveis e/ou vapor volátil, exposição ao tabaco e exposição à inalação ambiental durante a gravidez e após o nascimento (presença de atividades industriais, pedreiras ou postos de gasolina perto do domiícilio/ trabalho/ creche/ escola). Foram também analisados poluentes troposféricos nos dois períodos: material particulado (PM10), dióxido de enxofre (SO2), dióxido de nitrogênio (NO2), ozônio (O3) e monóxido de carbono (CO). Resultados: Durante a gravidez, o fumo fetal (OR= 3,43, IC 95%: 1,45-8,12, p=0,005) e a exposição ocupacional materna (OR= 13,69, IC95%: 4,43-42,27, p < 0,001) se mostraram fatores de risco independentes para AIJ. Em contrapartida, o fato de a mãe trabalhar fora de casa (OR= 0,06, IC 95%: 0,02- 0,16, p < 0,001) e o ganho de peso ideal da mãe (OR = 0,36, IC 95%: 0,16-0,83, p= 0,017) apresentaram associação negativa. Para o período após o nascimento até o diagnóstico de AIJ, fumo passivo (OR= 3,6, IC 95%: 1,76- 7,31, p < 0,0001) e exposição ao ozônio durante o segundo ano de idade (OR= 2,76, IC 95%: 1,20-6,37, p= 0,017) foram fatores de risco independentes e significativos para o diagnóstico da AIJ. Conclusão: O fumo passivo, a exposição ao ozônio no segundo ano de vida e a exposição ocupacional materna são destacados como importantes fatores de risco para a AIJ / Juvenile idiopathic arthritis (JIA) is a heterogeneous group of diseases characterized by chronic inflammation in one or more joints with onset in children under 16 years of age. Air pollution has been blamed for increased morbidity and mortality in cardiorespiratory diseases, but few studies have evaluated the effects of prolonged exposure on chronic inflammatory diseases. Some studies show an association between smoking and onset of rheumatologic illness in adults, and others show an association of smoking mothers during pregnancy with the development of JIA in children. However, there are few studies in the literature to date evaluating exposure to air pollution and JIA. Objective: To evaluate the influence of exposure to inhalable environmental factors during pregnancy and after birth until JIA diagnosis in residents of the São Paulo metropolitan area. Methods: Case-control study comprising 66 JIA patients and 124 healthy controls matched by age and gender, living in the Sao Paulo metropolitan area until JIA diagnosis, and whose mothers had resided in this region during pregnancy. A structured and reliable questionnaire (kappa index for test-retest was 0.80) assessed demographic data, gestational and perinatal-related factors, mothers\' work-related exposure during pregnancy to inhalable particles and / or volatile vapor, exposure to inhalable elements during pregnancy and after birth (work-related exposure to inhalable particles and/or volatile vapor, exposure to tobacco and the presence of industrial activities, quarries or gas stations near the home/ work/ daycare/ school). Tropospheric pollutants included: particulate matter (PM10), sulphur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3) and carbon monoxide (CO). Results: During pregnancy, fetal smoking (OR=3.43, 95%CI: 1.45-8.12, p=0.005) and mothers\' work-related exposure (OR=13.69, 95%CI: 4.43-42.27, p < 0.001) were independent significant risk factors for JIA diagnosis. In contrast, working mother (OR=0.06, 95% IC: 0.02-0.16, p < 0.001) and ideal mother weight gain (OR=0.36, 95% IC:0.16-0.83, p=0.017) presented a negative association. After birth until JIA diagnosis, secondhand smoking (OR=3.6, 95% IC: 1.76-7.31, p < 0.0001) and exposure to O3 during the second year of age (OR=2.76, 95% IC: 1.20-6.37, p=0.017) were independent and significant risk factors for JIA diagnosis. Conclusion: Secondhand smoking, exposure to O3 during the second year of age and mothers\' work-related exposure are highlighted as important risk factors to JIA
216

Polymorphisme érythrocytaire : approche anthropologique et interprétation de patterns de diversité génétique, entre peuplement et sélection / Red cell polymorphism : anthropological approach and interpretation of genetic diversity patterns, between settlement and selection

Petit, Florence 22 June 2018 (has links)
Mon travail de thèse est fondé sur la recherche d’une meilleure compréhension de la distribution géographique des polymorphismes érythrocytaires: antigènes de surface des systèmes de groupes sanguins érythrocytaires (GSE) et glucose-6-phosphate déshydrogénase (G6PD) intracellulaire. L’analyse sur 75 populations d’Asie des fréquences de l'allèle DI*01 du système de GSE Diego, des haplotypes C2-M217 et C2-M401 du chromosome Y, des coordonnées géographiques et des langues, a pu montrer la corrélation entre ces marqueurs. La répartition de DI*01 semble suivre les conquêtes mongoles, avec une expansion radiale depuis la Mongolie, porté par les nomades de langue Altaïque présentant C2-M217 et C2-M401. L'étude du gène G6PD chez 80 individus de Guyane Française de la communauté des Noirs Marrons originaire d’Afrique sub-Saharienne, aborde les relations santé-environnement. Les mutations du déficit en G6PD caractéristiques des variants sub-Sahariens ont été retrouvées chez une personne sur huit. La répartition du déficit était inconnue en Guyane Française et est encore mal connue en Amérique Latine et dans les Caraïbes, où sévit encore Plasmodium vivax dont le traitement nécessite l’utilisation de la primaquine pouvant entraîner une hémolyse sévère chez les individus G6PD-déficients. Mon troisième objectif a été de mettre en évidence l’influence de différents facteurs sur la répartition des polymorphismes de 10 systèmes de GSE étudiant 343 populations. Par des modélisations, les fréquences alléliques ont été confrontées aux données environnementales et culturelles. Enfin, une étude a été réalisée sur le système Duffy avec des analyses de détection de la sélection sur données SNP. / My Ph.D. work is based on the search for a better understanding of the geographical distribution of red blood cell polymorphisms: the surface antigens of red cell blood group systems (BGS) and the intracellular glucose 6-phosphate dehydrogenase (G6PD). The analysis on 75 Eurasian populations of frequencies of the DI*01 allele coding for Diego a antigen of Diego BGS, the C2-M217 and C2-M401 haplotypes of the Y chromosome, geographic coordinates and languages, has shown a correlation between these markers. The DI*01 distribution seems to follow the Mongol conquests, carried by the Altaic-speaking nomads possessing the C2-M217 and C2-M401 haplotypes with a radial expansion from Mongolia. The study of the G6PD gene in 80 individuals from French Guiana of the Noir Marron community originating from sub-Saharan Africa, addresses health-environment relations. Characteristic mutations of sub-Saharan variants of G6PD deficiency have occurred in one in eight people. The G6PD deficiency distribution was previously unknown in French Guiana and is still poorly known in Latin America and the Caribbean, where Plasmodium vivax still cracks down. Its treatment requires the use of primaquine which may cause severe haemolysis in G6PD-deficient individuals. My third objective was to highlight the influence of different factors on the distribution of polymorphisms of 10 BGS studying 343 populations. Through model adjustments, allelic frequencies have been confronted to environmental and cultural data. Finally, a study has been also conducted on the Duffy BGS by analyses of detection of natural selection on SNP data.
217

O gerenciamento ambiental como instrumento preventivo de defesa do meio ambiente

Lopes, Márcio Mauro Dias 06 May 2008 (has links)
Made available in DSpace on 2016-04-26T20:27:11Z (GMT). No. of bitstreams: 1 Marcio Mauro Dias Lopes.pdf: 790608 bytes, checksum: 750b6129fc946e4e1b99d379f70ee4a1 (MD5) Previous issue date: 2008-05-06 / Objective: To analyze the different elements related to environmental management in company as instrument for environmental defense. Justification: The presented defense sense is based on the presupposition that the environment needs actions of preventive nature and not reactive any more. Hypothesis: to analyze the different tools for environmental management that propitiate the development of companies within a criterium of environmental preservation in all working phases of an enterprise. Methods: Thus, the present work corresponds to a bibliographical review of different subjects that provide basis to the Brazilian environmental management, still including survey of articles and reports produced in symposia, associated to the practical experience of activities linked to the area. Results: Therefore, a comprehensive work was obtained as result, which shows that it is possible to make compatible development and environmental preservation / Objetivo: analisar os diferentes elementos relacionados ao gerenciamento ambiental na empresa como instrumento preventivo de defesa do meio ambiente. Justificativa: O sentido de defesa apresentado baseia-se no pressuposto de que o ambiente necessita de ações de caráter preventivo e não mais reativo. Hipótese: analisar algumas das ferramentas de gestão ambiental que propiciem o desenvolvimento das empresas dentro de um critério de preservação do meio ambiente em todas as fases de funcionamento. Aspectos Teórico-metodológicos: o presente trabalho constitui-se pela revisão bibliográfica de diferentes assuntos que embasam a gestão ambiental brasileira, incluindo-se ainda a pesquisa em artigos e relatórios produzidos em simpósios, associados à vivência prática do autor nas atividades ligadas à área. Resultados: obteve-se como resultado um trabalho abrangente, porém não esgotado, que demonstra ser possível compatibilizar o desenvolvimento com a preservação do meio ambiente
218

Avaliação da influência de fatores ambientais sobre o diagnóstico de artrite idiopática juvenil em crianças e adolescentes / Evaluation of the influence of environmental factors on the juvenile idiopathic arthritis in children and adolescents

Camila Maria Paiva França 14 March 2017 (has links)
A artrite idiopática juvenil (AIJ) constitui um grupo heterogêneo de doenças que se caracteriza por inflamação crônica em uma ou mais articulações, com diagnóstico em menores de 16 anos de idade. A poluição atmosférica tem sido responsabilizada pelo aumento da morbidade e mortalidade em doenças cardiorrespiratórias, mas poucos estudos avaliaram os efeitos da exposição prolongada sobre doenças inflamatórias crônicas. Alguns estudos demonstram associação entre fumo e início da doença reumatológica em adultos e outros mostram associação de mães fumantes durante a gravidez com desenvolvimento de AIJ nos filhos. Entretanto, existem poucos estudos na literatura avaliando a exposição à poluição do ar e AIJ. Objetivo: avaliar a influência de poluentes ambientais inalatórios como fatores de risco no desenvolvimento da AIJ em pacientes residentes na Região Metropolitana de São Paulo, acompanhados em um serviço terciário de Reumatologia Pediátrica. Metodologia: Este foi um estudo retrospectivo, do tipo caso-controle, que incluiu 66 pacientes com AIJ e 124 controles saudáveis, semelhantes em idade e gênero, residentes na Região Metropolitana de São Paulo, desde a gestação até o diagnóstico da doença. Um questionário estruturado e com alto índice de confiabilidade (índice kappa para teste-reteste 0,80) avaliou dados demográficos, fatores relacionados à gestação e ao período perinatal, exposição ocupacional materna durante a gravidez a partículas inaláveis e/ou vapor volátil, exposição ao tabaco e exposição à inalação ambiental durante a gravidez e após o nascimento (presença de atividades industriais, pedreiras ou postos de gasolina perto do domiícilio/ trabalho/ creche/ escola). Foram também analisados poluentes troposféricos nos dois períodos: material particulado (PM10), dióxido de enxofre (SO2), dióxido de nitrogênio (NO2), ozônio (O3) e monóxido de carbono (CO). Resultados: Durante a gravidez, o fumo fetal (OR= 3,43, IC 95%: 1,45-8,12, p=0,005) e a exposição ocupacional materna (OR= 13,69, IC95%: 4,43-42,27, p < 0,001) se mostraram fatores de risco independentes para AIJ. Em contrapartida, o fato de a mãe trabalhar fora de casa (OR= 0,06, IC 95%: 0,02- 0,16, p < 0,001) e o ganho de peso ideal da mãe (OR = 0,36, IC 95%: 0,16-0,83, p= 0,017) apresentaram associação negativa. Para o período após o nascimento até o diagnóstico de AIJ, fumo passivo (OR= 3,6, IC 95%: 1,76- 7,31, p < 0,0001) e exposição ao ozônio durante o segundo ano de idade (OR= 2,76, IC 95%: 1,20-6,37, p= 0,017) foram fatores de risco independentes e significativos para o diagnóstico da AIJ. Conclusão: O fumo passivo, a exposição ao ozônio no segundo ano de vida e a exposição ocupacional materna são destacados como importantes fatores de risco para a AIJ / Juvenile idiopathic arthritis (JIA) is a heterogeneous group of diseases characterized by chronic inflammation in one or more joints with onset in children under 16 years of age. Air pollution has been blamed for increased morbidity and mortality in cardiorespiratory diseases, but few studies have evaluated the effects of prolonged exposure on chronic inflammatory diseases. Some studies show an association between smoking and onset of rheumatologic illness in adults, and others show an association of smoking mothers during pregnancy with the development of JIA in children. However, there are few studies in the literature to date evaluating exposure to air pollution and JIA. Objective: To evaluate the influence of exposure to inhalable environmental factors during pregnancy and after birth until JIA diagnosis in residents of the São Paulo metropolitan area. Methods: Case-control study comprising 66 JIA patients and 124 healthy controls matched by age and gender, living in the Sao Paulo metropolitan area until JIA diagnosis, and whose mothers had resided in this region during pregnancy. A structured and reliable questionnaire (kappa index for test-retest was 0.80) assessed demographic data, gestational and perinatal-related factors, mothers\' work-related exposure during pregnancy to inhalable particles and / or volatile vapor, exposure to inhalable elements during pregnancy and after birth (work-related exposure to inhalable particles and/or volatile vapor, exposure to tobacco and the presence of industrial activities, quarries or gas stations near the home/ work/ daycare/ school). Tropospheric pollutants included: particulate matter (PM10), sulphur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3) and carbon monoxide (CO). Results: During pregnancy, fetal smoking (OR=3.43, 95%CI: 1.45-8.12, p=0.005) and mothers\' work-related exposure (OR=13.69, 95%CI: 4.43-42.27, p < 0.001) were independent significant risk factors for JIA diagnosis. In contrast, working mother (OR=0.06, 95% IC: 0.02-0.16, p < 0.001) and ideal mother weight gain (OR=0.36, 95% IC:0.16-0.83, p=0.017) presented a negative association. After birth until JIA diagnosis, secondhand smoking (OR=3.6, 95% IC: 1.76-7.31, p < 0.0001) and exposure to O3 during the second year of age (OR=2.76, 95% IC: 1.20-6.37, p=0.017) were independent and significant risk factors for JIA diagnosis. Conclusion: Secondhand smoking, exposure to O3 during the second year of age and mothers\' work-related exposure are highlighted as important risk factors to JIA
219

Environmental impacts on native bumble bee pollinators in an agricultural landscape of western Oregon

Skyrm, Kimberly M. 13 May 2011 (has links)
Bumble bees provide vital pollination services in both native and agricultural landscapes. However, in recent years, bumble bee populations have experienced global population declines. The primary causes of these declines have been attributed to the environmental impacts of pathogens, pesticide use and habitat fragmentation. While research has examined the impacts of pathogens, there is limited information on the effects of pesticides and habitat fragmentation on native bumble bees. Hence, the objectives of my dissertation research were to: 1) assess the toxicological impacts of pesticides used in two important bee-pollinated crops on queens and workers; 2) determine the impacts of forage resource availability on bumble bee colonies; 3) examine pollen foraging behavior of bumble bees in a late season mass-flowering agricultural landscape; and 4) document observations on trends towards bivoltinism in three western North American bumble bees. This research was conducted in the lab using wild and lab reared colonies, and in an agricultural landscape in the Willamette Valley of Western Oregon. In pesticide bioassays the impacts of residual toxicity of five classes of pesticides used in highbush blueberry and red clover cropping systems, were tested on queen and worker bumble bees, respectively. The results indicated variation in responses to the same insecticide by queens and workers, and to the same class of compounds by workers. Also, toxic effects were documented for both queens and workers to pesticides considered to be "safe" for bees. The impacts of forage resource availability were evaluated by exposing bumble bee colonies to four quantities of pollen, four quantities of nectar and three feeding frequencies of pollen. The study documented an inverse relationship between larvae and workers to resource type and availability. In addition, the type of larval mortality displayed by colonies, larval ejection or within clump mortality, was dependent on worker mortality. The individual and colony-level pollen foraging behavior of bumble bees was examined by placing colonies in red clover. Observations in the field on forager abundance, and at the colony-level on the duration and number of pollen trips and weight of stored pollen documented that red clover is an important resource for bumble bees. Pollen analysis revealed that in addition to red clover, Himalayan blackberry was also a key forage resource for bumble bees. Red clover resources at the end of the season may also benefit bumble bees by allowing for the creation of a second generation. Observations on both field and lab-reared queens document a trend towards bivoltinism in three species of western North American bumble bees. Agricultural habitats are vital for sustaining bumble bee populations. However, given the potential for pesticide impacts and temporal availability of flowering plants, these landscapes must be managed to provide maximum benefit to bumble bees. Results from this research should assist growers and researchers in developing landscape management and production practices geared toward the conservation and enhancement of native Bombus spp. populations in western Oregon. / Graduation date: 2011
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Tree Diameter Growth : Variations And Demographic Niches In A Tropical Dry Forest Of Southern India

Nath, Cheryl D 07 1900 (has links)
Tree growth influences forest community dynamics and responses to environmental variations, but currently is not well understood. Tree growth in highly diverse wet tropical forests have been well studied and characterised compared to the species-poor dry tropical forests. Thus, it is not clear if growth rates and community dynamics of dry forests are similar to those of wet forests, given the longer dry season, greater rainfall variability, more open canopy and lower number of species in dry forests. This thesis focuses on identifying important factors that influence tree diameter growth rates in the dry tropical forest at Mudumalai, southern India, and also compares growth patterns at this dry forest with those at moister forests. The thesis thus contributes towards closing the gap in understanding of tree growth patterns across the tropics. An initial analysis involving matrix-based population projections of four common canopy species at Mudumalai showed that variations in diameter growth have the potential to drastically modify population trajectories of dominant species. Thus the main focus of this thesis is aimed at identifying the important intrinsic and extrinsic factors affecting growth in this dry forest, as this information could be useful for future management of the forest. The second important aim of the thesis was to find out if growth rates are influenced by different sets of factors in tropical dry versus moist forests. A large permanent 50ha plot vegetation monitoring plot was set up in 1988-89 in the Mudumalai dry deciduous forest, and was subsequently monitored annually by staff of the Centre for Ecological Sciences. Data used in this thesis represent a 12-year interval between 1988 and 2000. Girth measurements were obtained from all woody tree stems ≥1cm in diameter every four years during this 12 year interval, which provided three census intervals of diameter increment data on >13,000 trees. For the comparison between dry and moist deciduous forests, data were obtained from a similar large plot maintained and monitored at the Barro Colorado Island (BCI) in Panama. Influences of the intrinsic factors, tree size, individual identity, species identity and growth form, were examined using t-tests, Wilcoxon signed ranks tests, linear regressions, analysis of variance (ANOVA), principal components analysis (PCA) and cluster analysis. Among the intrinsic factors tested, species identity explained approximately 20% of growth rates at the community level, while tree diameter explained less of growth variation, and growth form had a minor influence on growth. Growth rates also were examined for variations across the three census intervals, and for relationships with rainfall and survival from fire. Statistical tests included t-tests, Wilcoxon and other non-parametric sign tests, logistic regression and ANOVA. Most species and individuals showed significant reductions of growth in the second census interval (1992-1996), and growth rates of most trees were positively related to rainfall. Growth rate variations generally were not related to survival from fire, and few species were capable of escaping fire mortality by fast growth. Spatial environmental influences were tested in the commonest fifteen species, using five habitat categories, local elevation, slope, aspect, and the biotic neighbourhood variables of local conspecific and heterospecific density. Statistical tests included analysis of covariance, multiple linear regression and redundancy analysis. The tests were quadrat-based or individual-based, and species' growth responses were tested at different levels of distance and spatial scale. Topographic features and habitat categories had ephemeral effects on species growth. Only the most dominant species, Lagerstroemia microcarpa, showed consistent conspecific neighbour density effects. Redundancy analysis using a subset of common species and environmental factors did not reveal common growth responses to spatial environmental factors. Comparison of factors influencing growth at Mudumalai versus at BCI using multiple factor ANOVA and multiple linear regressions showed a similar influence of temporal variation at the two sites, but stronger and more widespread influence of tree size (diameter) at BCI. The greater influence of tree size at BCI may be related to greater light limitation in this dense moist forest. Spatial environmental factors had weak influences at both plots. Species were less differentiated from each other at the more diverse BCI plot compared to the relatively species-poor Mudumalai plot, suggesting that species' growth niches may be weakly related to diversity across tropical forests. Overall the results showed that among the factors tested species identity and census intervals were the most important influences on diameter growth at the Mudumalai dry deciduous forest. Tree diameter was less important and less consistent in affecting growth at the Mudumalai dry forest, contrary to expectations based on moist tropical forests where this relationship has been established previously. When comparing Mudumalai and BCI, the relative importance of different factors was different at the two sites, and the most important difference was a dominant influence of light limitation at the wetter forest in Panama. In terms of management applications, this study showed that fires at Mudumalai might be an inescapable source of mortality for many vulnerable species, and improved fire management is crucial for long term survival of species in this dry forest. At a larger scale, light and other environmental variables were found to influence growth differently at Mudumalai compared to BCI. This suggests that location-specific responses may be important for projections of tree biomass and carbon sequestration, especially under future climatic change scenarios.

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