Spelling suggestions: "subject:"intensification,"" "subject:"intensifications,""
181 |
Éco-immunologie de l'hirondelle bicolore (Tachycineta bicolor) : effets environnementaux et génétiques sur une fonction immunitaire innéeSchmitt, Clarence January 2017 (has links)
Depuis l'émergence récente de l'éco-immunologie, une question majeure a été soulevée: pourquoi, malgré une évolution des systèmes immunitaires de plus en plus complexes, les hôtes sont encore sensibles aux infections? Plusieurs facteurs expliquent cette variation. Par exemple, produire une réponse immunitaire nécessite des ressources énergétiques, qui peuvent varier selon l'environnement. Une distribution hétérogène des ressources alimentaires causée notamment par l'intensification agricole pourrait avoir des conséquences sur les réponses immunitaires des populations sauvages. D'autre part, cette variation peut être due à des facteurs génétiques. Pendant mon doctorat, j'ai étudié les effets de l'intensification agricole sur une fonction du système immunitaire inné (en opposition à acquis) d'une population sauvage d'Hirondelle bicolore (Tachycineta bicolor), un passereau migrateur qui niche au Sud du Québec au Canada. J'ai aussi étudié les effets de la variation de gènes immunitaires sur la fonction immunitaire innée et les conséquences sur la reproduction de ce passereau.
D’abord, j'ai déterminé l'effet de l'intensification agricole sur la capacité bactéricide du plasma contre E. coli chez les adultes d'Hirondelle bicolore. Contre toute attente, l'intensification agricole a eu un effet positif sur la capacité bactéricide contre E. coli. Cela pourrait suggérer une exposition plus forte à des souches de E. coli dans les milieux intensifs, où les individus développeraient une capacité bactéricide plus importante que les individus en milieux non-intensifs. Ensuite, je me suis aussi intéressée aux effets génétiques qui pourraient influencer la capacité bactéricide des individus. Pour cela, j'ai utilisé des gènes de β-défensine qui codent pour des peptides impliqués dans plusieurs aspects du système immunitaire, dont les réponses immunitaires innées. Les résultats indiquent que certains gènes de β-défensine influencent la capacité bactéricide des individus. Finalement, j'ai aussi montré une association positive entre la capacité bactéricide des adultes et la proportion d'oisillons ayant survécu jusqu’à l’envol, ce qui suggère l’absence de compromis énergétique entre cette fonction immunitaire innée et l'effort de reproduction.
Mes recherches de doctorat soulèvent des questions sur l'importance de la capacité bactéricide et ce qu'elle reflète chez les populations sauvages de passereaux. Mes travaux représentent aussi une première tentative de liaison entre la variation des gènes de β-défensine et une fonction immunitaire mais aussi avec des traits de succès reproducteurs, et ouvrent la voie à l’étude des effets des gènes de β-défensine sur les traits liés à l’aptitude phénotypique chez des organismes sauvages.
|
182 |
Intensification of lignocellulosic bioethanol production process using multi-staged membrane bioreactorsUwinez, Clarisse January 2019 (has links)
The exploitation of lignocellulosic materials with the aim of producing high value-added products will potentially counteract concerns related to the depletion of fossil resources or exponential population growth. Bioethanol produced from lignocellulosic agriculture residue exhibits promising alternative to the petroleum-based fossil fuel which reduces net emission of greenhouse gases (GHG). But, due to certain technological barriers, the large scale production of lignocellulosic bioethanol has not been successfully commercialized. In this thesis, membrane filtration as an energy efficient separation process with low environmental impact was chosen with a possibility of improvement. Interconnected multi-staged microfiltration submerged membrane bioreactors (MBRs) set-up has been applied in order to separate suspended solids, obtain high concentration of yeast inside the bioreactor, and recover particle-free ethanol stream in a continuous high productivity process. The MBRs were effectively optimized comparing to different constant permeate fluxes of 21.9 LMH, 36.4 LMH, and 51 LMH. Moreover, membrane bioreactor performed effectively at low flux 21.9 LMH up to 262 h comparing to other applied fluxes. During continuous hydrolysis, membrane showed the capability of lignin recovery nearly 70% of medium SS content in all applied flux. Although the conversion rate of total sugars by concentrated cells were similar, yeast cells proved the capability of inhibitor tolerance, and to co-utilize 100% of glucose and up to 89% of xylose, resulted in bioethanol volumetric productivity of 0.78 g ethanol/l per hour 1.3 g ethanol/l per hour and 1.8 g ethanol/l per hour for 21.9 LMH, 36.4 LMH, and 51 LMH respectively. Moreover, the effect of different factors such as filtration flux, medium quality and backwashing on fouling and cake-layer formation in submerged MBRs during continuous filtration was thoroughly studied.
|
183 |
The Effect of Agricultural Intensification on Nitrate Concentrations in Shallow Groundwater in Two Watersheds in Ethiopia / Jordbruksintensifierings effekt på nitratkoncentrationer i ytliga grundvatten i två avrinningsområden i EtiopienLarsson, Anna January 2019 (has links)
Sustainable intensification of agricultural will be crucial in the future to feed a growing population and address ongoing climate changes. Ethiopia is still dominated by traditional agricultural practices and the population is expected to increase from todays 110 million to 174 million in 2050, making sustainable implementations of intensified agricultural methods crucial. In this study, two watersheds with differences in agricultural intensification and geophysical attributes in Amhara region, north western Ethiopia, are evaluated based on nitrogen content in wells. An attempt to explain the differences in contamination levels of nitrate between the two watersheds are done by examining the usage of fertilisers, amount of livestock and irrigation habits as well as topography. The result showed that the less intensified watershed exceeded the WHO guidelines for nitrate more frequently than the more intensified watershed. Temporal patterns in contamination levels in specific wells could be seen in both watersheds, where the WHO guidelines being most frequently exceeded in July and September versus July and November for the watersheds respectively. No significant correlations between nitrate concentration and explaining parameters were detected in any of the watersheds. The methods used in this paper could not explain the variations in contamination levels. The results imply that the nitrate responses are very site-specific. Evaluations including more precise details on crop management and subsurface flow patterns as well as on other factors influencing contamination levels in wells, such as distance to household and cattle, are needed in further investigations as agriculture continues to intensify / En hållbar utveckling av jordbruket kommer att vara avgörande för att föda en växande befolkning och möta pågående klimatförändringar. I Etiopien domineras jordbruket av traditionella metoder och befolkningen i landet förväntas öka från dagens 110 miljoner till 174 miljoner år 2050, vilket medför att hållbara lösningar gällande bevattning och gödslingsanvändning blir viktiga. Två avrinningsområden med olika karaktär gällnade intensifiering av jordbruk och topografi i Amhara-regionen i nordvästra Etiopien utvärderas utifrån kvävekoncentrationer i brunnar. Ett försök att förklara kvävekoncentrationer görs genom att utvärdera användningen av gödslingsmedel, mängd boskap och bevattningsvanor. Resultatet visade att det mindre intensifierade avrinningsområdet överskred WHO:s riktlinjer vid fler tillfällen än den mer intensifierade. Temporala skillnader i föroreningsnivåer kunde ses i specifika brunnar i båda avrinningsområdena, där WHO:s riktlinjer överskreds mest frekvent i juli och september respektive juli och november. Inga signifikanta korrelationer mellan nitratkoncentration och förklarande faktorer påvisades i någon av avrinningsområdena. Metoden som användes i studien kunde inte förklara de variationer som förekom i brunnarnas kontamineringsnivåer. Resultaten indikerar dock att orsakerna är platsspecifika och studier baserade på mer detaljerade data om odlingsätt och markvattenflöden samt andra påverkande faktorer, såsom avstånd till hushåll och boskap behöver göras då intensifieringen av jordbruket fortskrider.
|
184 |
"Reestruturação produtiva e saúde do trabalhador: um estudo com os trabalhadores de uma indústria avícola" / Productive restructuring and worker`s health: one study with the workers of a poultry industryNeli, Marcos Acacio 11 July 2006 (has links)
As mudanças na organização, nos processos e nas relações de trabalho, que estão no bojo do processo de reestruturação produtiva capitalista, se intensificaram a partir das últimas décadas do século XX, resultando em um quadro de agravamento das condições de trabalho que interfere diretamente nas condições de saúde dos trabalhadores de forma geral. Esta pesquisa se debruça sobre estas questões, tomando como objeto de investigação a atividade laboral dos trabalhadores do setor de alimentos empregados em uma unidade de processamento de aves, pertencentes a uma das maiores empresas deste ramo no país, localizada na região oeste do Estado do Paraná. A metodologia adotada para esta pesquisa foi de cunho qualitativo e foram utilizadas como instrumento de coleta de dados, entrevistas abertas. Ao todo foram entrevistados dez trabalhadores, de ambos os sexos, que foram contatados através da técnica de indicação sucessiva, somando aproximadamente 5h e 30m de gravação. Foram também realizadas entrevistas com a psicóloga e com o presidente do sindicato a qual estão vinculados os trabalhadores desta indústria avícola. A partir das informações obtidas com os trabalhadores foi realizada a reconstituição do processo de trabalho observando a sua dinâmica (destacando as questões referentes à organização e divisão do trabalho e aquelas relacionadas ao uso de tecnologias), e a descrição do ambiente de trabalho; visando compreender como são as condições de trabalho para saber se as mesmas interferem na saúde dos trabalhadores. A análise dos conteúdos das entrevistas revelou que a organização do trabalho fundada nos preceitos taylorista/fordista predominante naquele setor, foi acrescida por outras técnicas de organização da produção e do trabalho, inspiradas no modelo japonês ou toyotista, e que estão interferindo nas condições de saúde dos trabalhadores tanto física quanto psíquica. O crescimento de casos de LER na categoria aparece de forma destacada nos depoimento colhidos. / The changes in organization, in work processes and relationships that are basic for the capitalist productive restructuring process, which have been intensified for the last decades in the 20th century, have resulted in a state of working conditions aggravation, which directly interferes in the workers´ health conditions, in general. This paper delves into these questions, having as its investigation object the workers´ labor activities in the food sector, who were employed in a poultry processing plant which belongs to one of the country´s largest companies in its field, located in the west of Paraná state. The adopted methodology for this research was qualitative, and it was used as an instrument for data collection in open interviews. Altogether, ten employees of both sexes were interviewed, who were contacted through the successive indication technique, logging approximately a 5-hour-and-30-minute recording. There was also an interview with the psychologist and the president of the union these poultry plant´s workers are associated with. Based on the information obtained from the workers, the reconstitution of the work process was conducted, observing its dynamics (pointing out the issues referring to work organization and division and those related to the use of technologies), and the description of the work setting, with a view to understand what the working conditions are like and discover if they interfere in the employees´ health. The analysis done on the contents of the interviews revealed that the work organization fashioned around Taylorist/Fordist precepts, predominant in that sector, was increased by other organization techniques for production and work, inspired by the Japanese model (or Toyotist), and that they have been interfering in the workers´ physical and mental health conditions. The increasing number of LRE cases in this category is outstandingly apparent in the testimonies.
|
185 |
Intensidades de emissão de gás metano de bovinos Nelore terminados a pasto e cruzados em confinamento / Methane emission intensities from beef cattle Nellore finished on pasture and crossbred in feedlotSakamoto, Leandro Sannomiya 07 August 2018 (has links)
O aumento das emissões de gases de efeito estufa (GEE) por ações antrópicas vem contribuindo para o aquecimento global que causam as mudanças climáticas. O setor agropecuário tem participação nessas emissões, principalmente devido a produção de alimentos necessária para suprir a demanda crescente da população, sendo a emissão de metano (CH4) entérico pelos bovinos o foco das discussões. Diante desta realidade, o objetivo deste trabalho foi avaliar as intensidades de emissão de CH4 de bovinos Nelore em sistemas de pastagem e bovinos cruzados em confinamento na fase de terminação. Foram avaliados 48 animais da raça Nelore de duas safras, sendo 24 por safra, distribuídos nos 4 sistemas de produção em pastagem: sob manejo intensivo irrigado com alta lotação (IAL), sob manejo intensivo de sequeiro com alta lotação (SAL), em recuperação sob manejo de sequeiro com lotação animal moderada (SML) e degradada com baixa lotação animal (DEG). A mensuração de metano foi feita pela técnica do gás traçador hexafluoreto de enxofre (SF6). Também foram avaliados 63 animais cruzados provenientes de vários grupos genéticos, agrupados em proporção de Adaptado de 25,00% e 37,50% (1A), de 43,75% e 50,00% (2A) e de 56,25%, 62,50%, 68,75% e 75% (3A), em proporção de Bos taurus: 31,25%, 50,00%, 56,25% e 75,00%, e segundo a porcentagem de Heterozigose: 50,00% e 62,50% (1H), 81,25% (2H), e 100% (3H). A mensuração do metano foi através dos cochos automatizados (Greenfeed). Todos os animais avaliados eram castrados. Amostras das pastagens foram analisadas e o consumo dos animais Nelore foram estimados, já no confinamento o consumo foi mensurado através do equipamento GrowSafe. Em ambos experimentos foram registrados dados de desempenho animal (peso vivo, ganho de peso, conversão alimentar), de carcaça (área de olho de lombo do músculo Longissimus, espessura de gordura, peso de carcaça quente (PCQ) e rendimentos de carcaça (RendC) e do ganho (RendG)) e variáveis relacionadas ao metano. Foram apresentados também dados por hectare nos sistemas a pasto. Os dados foram analisados pelo procedimento MIXED do programa SAS 9.3. Sistemas mais intensificados apresentaram melhores resultados da qualidade de forragem comparados com o DEG, isto refletiu nos resultados de consumo e desempenho desses animais que apresentaram piores resultados. O DEG foi o menos produtivo de todos. Algumas variáveis relacionadas ao CH4 apresentaram diferenças entre os tratamentos: 1) a emissão em relação ao ganho de peso diário (CH4GPD) foi menor para o sistema IAL (371 g CH4/kg GPD) comparado aos sistemas DEG (478,4) e SAL (484,5), o sistema SML (404,0) não diferenciou dos IAL e DEG; 2) a energia bruta perdida na forma de CH4 (YM) apresentou maiores valores para os sistemas SAL e DEG comparado aos IAL e SML. Os sistemas mais intensificados apresentaram maior taxa de lotação (p <,0001) e maior ganho de peso e carcaça (p <,0001) por hectare. O SAL apresentou menor intensidade de emissão (IE) calculada pelo RendG que o DEG (p = 0,0269). Entretanto os sistemas não apresentaram diferenças na IE por ganho de peso (p = 0,3602) e por kg de carcaça calculado pelo RendC (p = 0,1567), apesar das diferenças parciais encontradas nas emissões por ano e por taxa de lotação (p <,0001) com valores mais altos para os sistemas intensificados, mostrando a possibilidade de maior produção de carne com uma mesma IE, considerando apenas a emissão de metano entérico. Os agrupamentos dos animais confinados apresentaram diferenças nas variáveis de desempenho, porém apenas a classificação pela heterozigose apresentou diferenças nas variáveis de metano. Animais 3H apresentaram melhores resultados de desempenho em relação aos animais 1H. Para as variáveis relacionadas a carcaça, não houve diferença no PCQ (p = 0,5842), porém animais 2H apresentaram maior rendimento cárneo que animais 1H (p = 0,0177), e carcaça mais magra que os demais (p = 0,0007). Em relação ao metano, animais 2H apresentaram melhores resultados em comparação aos animais 3H, porém os dois grupos apresentaram uma IE calculada pelo RendC menor que animais 1H (p = 0,0173). Apesar das diferenças encontradas entre os níveis de intensificação das pastagens ou entre os grupos genéticos estudados, é importante avaliar o sistema como um todo, como o sequestro de carbono dos solos, a emissão de óxido nitroso, produção de dejetos, entre outros e não apenas a emissão de metano dos animais. Podemos concluir com este estudo que sistemas mais intensificados produzem mais carne. Animais com porcentagens de heterozigose acima de 81,25% podem apresentar menor IE de metano que animais com heterozigose abaixo de 62,5% na fase de terminação em confinamento. Além disso, carcaças mais magras com maior rendimento cárneo podem ser obtidas em animais com 81,25% de heterozigose. Para definir qual sistema de produção, grupo genético bovino, tipo de dieta, nível de intensificação utilizar, é importante verificar os que melhor se encaixam em sua estrutura visando uma produção sustentável. Os impactos ambientais causados pela atividade podem até serem neutralizados se o planejamento e a execução forem adequados ao seu objetivo. / Increase in greenhouse gas (GHG) emissions from anthropogenic actions has contributed to global warming that is responsible for climate change. The agricultural sector has participation in these emissions, mainly due to the food production necessary to supply the growing demand of the population, therefore the enteric methane (CH4) emission by cattle becomes the focus of the discussions. In view of this reality, the aim of this study was to evaluate methane emission intensities of Nellore cattle in pasture systems and crossbred cattle in feedlot, both in the finishing phase. Forty-eight animals from two production cycles were evaluated, with twentyfour in each cycle, distributed across four different pasture production systems: intensively managed irrigated pasture with high stocking rate (IHS), intensively managed dry land pasture with high stocking rate (DHS), recovering dry land pasture with moderate stocking rate (DMS) and degraded pasture with low stocking rate (DP). Methane emission was measured using the sulfur hexafluoride (SF6) gas tracer technique. We also evaluated sixty-three crossbreed animals from several genetic groups, grouped in proportion to Adapted of 25% and 37.5% (1A), 43.75% and 50% (2A) and 56.25%, 62.5%, 68.75% and 75% (3A), in proportion to Bos taurus: 31.25%, 50%, 56.25% and 75%, and according to the percentage of heterozygosis: 50% and 62.5% (1H), 81.25% (2H), and 100% (3H). Methane emission was measured through automated troughs (Greenfeed). All animals evaluated were castrated. Pasture samples were analyzed and Nellore animals\' intake was estimated, and in feedlot the intake was measured through the GrowSafe machine. In both experiments, animal performance (live weight, weight gain, feed conversion), carcass (Longissimus loin eye muscle area, fat thickness, hot carcass weight (HCW) and carcass yield (CY) and gain yield (GY)) data and variables related to methane were recorded. Data per hectare were also recorded in pasture systems. The data were analyzed using the MIXED process of the SAS 9.3 program. The more intensely managed systems presented higher yields of better quality forage, as well as superior animal performance when compared to the DP. Some variables related to CH4 showed differences between treatments: 1) emissions in relation to average daily weight gain (CH4ADG) were lower in the IHS system (371 gCH4/kgADG) compared to the DP (478.4) and DHS (484.5) systems; the DMS system (404.0) did not differ significantly from the IHS and DP; 2) gross energy lost in the form of CH4 (YM) demonstrated higher energy expenditure for the DHS and DP systems compared to the IHS and DMS. Intensified systems had higher stocking rate (p <.0001) and weight and carcass gain (p <.0001) per hectare. SAL presented lower emission intensity (EI) calculated by the GY than the DEG (p = 0.0269). However, the systems did not present differences in emission intensities per weight gain (p = 0.3602) and per kg of carcass calculated by carcass yield (p = 0.1567), despite the partial differences observed in emissions per year and per stocking rate (p <.0001) with higher values recorded for the intensified systems, showing the possibility of higher meat production with the same emission intensity, considering only the enteric methane emission. Groups of confined animals presented some differences in the performance variables, but only the classification by heterozygosity showed differences in the methane variables. Animals classified as 3H showed better performance compared to 1H animals. For variables related to the carcass, there was no difference in PCQ (p = 0.5842), but 2H animals presented higher carcass yield than 1H animals (p = 0.0177), and leaner carcass compared to the others (p = 0.0007). In relation to methane, 2H animals presented better results compared to 3H animals, but two groups had a lower EI calculated by the CY than 1H animals (p = 0.0173). Despite the differences found between pasture intensification levels or between genetic groups studied, it is important to evaluate the system as a whole, such as soil carbon sequestration, nitrous oxide emission, waste production, among others and not only methane emissions from animals. We can conclude from this study that intensified systems produce more meat. Animals with heterozygous percentages above 81.25% may presented lower emission intensity of methane than animals with heterozygosis below 62.5% in the feedlot finishing phase. In addition, leaner carcasses with higher beef yield may be obtained in animals with 81.25% heterozygosity. In order to define which production system, bovine genetic group, type of diet, level of intensification to use, it is important to verify the ones that fit best in its structure aiming a sustainable production. The environmental impacts caused by the activity can even be neutralized if planning and execution are appropriate to its objective.
|
186 |
Impact of climate change on the agro-ecological innovation of coffee agroforestery systems in central Kenya / Impact des changements climatiques sur les innovations agro-écologiques des systèmes agroforestiers du café au Kenya centralGebreeyesus, Kinfe Asayehegn 28 April 2017 (has links)
Le changement climatique et la variabilité ont des répercussions graves dans le secteur agricole des régions tropicales. Le secteur du café est sensible au changement climatique car il nécessite une température relativement froide et une plus grande durée des pluies. L'adaptation au changement climatique dans l'agroforesterie du café est donc importante pour traiter les impacts, mais il existe des obstacles et des limites. Le but de cette thèse était d'analyser les stratégies d'adaptation au changement climatique au centre du Kenya. Nous avons étudié différentes étapes de l'adaptation qui incluent (1) les connaissances sur le changement climatique et l'adaptation, la motivation à l'adaptation, (2) le choix actuel des stratégies d'adaptation et leurs déterminants, (3) les rôles du système d'innovation et du contexte institutionnel. Cette étude repose sur quatre sources d'information: - (1) groupes de discussion sur des questionnaires pré-définis, (2) enquêtes auprès des ménages, (3) entrevues auprès des intervenants et (4) données climatiques historiques sur le contexte de quatre types de systèmes de productions dans l’agriculture : les cultures vivrières, le café spécialisé, les systèmes diversifiés café-laiterie et les systèmes laitiers spécialisés, dans les zones caféières et vivrières. L'analyse des tendances de Mann-Kendal et l'estimateur de la pente de Sen ont été utilisées pour comparer les connaissances des agriculteurs sur les changements climatiques et l’historique des données climatiques, tandis que le modèle de Heckman a été utilisé pour analyser les stratégies d'adaptation et leurs déterminants. Les résultats soulignent des cohérences entre les connaissances des agriculteurs et l'analyse historique des données pour la température mais des incohérences avec le changement des précipitations. L'analyse de la perception par les agriculteurs révèle que les précipitations diminuent radicalement au fil du temps, alors qu'aucun élément de preuve concernant les précipitations ne permet d'appuyer la perception des agriculteurs. L'incohérence est donc corroborée par l'analyse des modèles. Les agriculteurs du secteur du café et des cultures vivrières se sont adaptés différemment aux changements climatiques. Les agriculteurs qui sont conscients des changements sont plus disposés à explorer les stratégies d'adaptation. Une partie des agriculteurs qui ne perçoivent pas le changement climatique adoptent des stratégies d’adaptation à des facteurs autres. L'adaptation au changement climatique est également déterminée par la performance institutionnelle et les différences de systèmes sectoriels d'innovation. La comparaison entre les secteurs du café et des produits laitiers révèle ainsi que les stratégies des acteurs du café sont limitées. En ce qui concerne l’élaboration des politiques, cette thèse contribue aux politiques d’accompagnement de l’adaptation au niveau des ménages, aux politiques de recherche agronomique et de négociation des accords internationaux. Les recommandations politiques au niveau des ménages se différentient selon trois scénarios. En premier lieu de l’intensification dans le café par l’innovation technologique. Les deux autres options politiques sont dans la diversification sectorielle dans la production laitière qui dépend de leur niveau de rentabilité. Les résultats de cette étude sont issus d’enquêtes sur l’analyse des systèmes d’innovation. D’autres options politiques sont proposées dans le développement de nouvelles infrastructures, des subventions pour accroitre les potentiels d’adaptation. Nous recommandons enfin de nouveaux sujets de recherche pour le futur. / Climate change and variability is the most widespread anthropogenic challenge affecting agricultural production and productivity particularly in the tropics. Coffee sector is sensitive to climate change as it requires relatively cold temperature and higher rainfall duration. Adaptation to climate change in the coffee agroforestry is, therefore, important to address the impacts, but there are barriers, and limits. The aim of this Thesis was to analyze the adaptation strategies to climate change in Central Kenya. We studied the steps in adaptation, which includes (1) the knowledge on climate change and adaptation, the motivation towards adaptation, (2) current choices of households’ adaptation strategies, and their determinants, (3) the roles of innovation system and institutional context to support adaptation. This study was based on four sources of information: - (1) Focus Group Discussions to predefine the questionnaires, (2) household surveys, (3) stakeholders interview, and, (4) historical climate data. The data collection considered four farming typologies; - food crops, specialized coffee, diversified coffee-dairy and specialized dairy farming systems in the coffee and food crops zones. Mann-Kendal trend analysis and Sen’s slope estimator were used to compare the farmers’ knowledge of climate change with the historical climate data, while Heckman model was used to analyze adaptation strategies and their determinants. The findings explore consistent results between farmers’ knowledge and historical data analysis for temperature, while inconsistency is observed in rainfall change. Analysis of farmers’ perception revealed rainfall is radically declining over time, while no evidence in rainfall record is found to support the farmers’ perception. The inconsistency is therefore, substantiated with analysis of patterns. Coffee and food crop farmers are found to adapt to climate change differently. Farmers who are aware of the changes are found more willing to explore adaptation strategies although some of the farmers who do not perceive the climate is changing are also adopting strategies for factors other than perception. The comparison between coffee and dairy sectors found that actors in the coffee are limited, the system is highly centralized with limited options for farmers to process and market their products, while the dairy sector is informally controlled by demand based business and comparatively, numerous actors. We conclude in this study that the patterns in rainfall affects the farming activities of the study area higher than the annual changes. Consequently, farmers adopt a series of adaptation strategies in response to their perception of changes in climate and economic pressure in the farm. This adaptation to climate change also depends on the nature of actors’ interaction and institutional context. In relation to policy development, this Thesis contributes to household level adaptation policies, research policies and international agreements and negotiations. The household level policy recommendations consists of three scenarios. Farmers’ intensification in coffee applying the right technological innovations. The second and third policy options are the diversification to dairy and complete sectoral transformation to dairy depending on the profitability and adaptation level of the sectors. The results in this study are derived from surveys and analysis of innovation systems. Other strategies such as new infrastructural development and institutional subsidies could be potential for adaptation. We therefore, recommend, these could be potential future research topics.
|
187 |
Trabalho intensificado e os transtornos mentais comuns em docentes de uma universidade p?blica na BahiaAzevedo, Caroline Almeida de 24 April 2017 (has links)
Submitted by Ricardo Cedraz Duque Moliterno (ricardo.moliterno@uefs.br) on 2018-07-16T19:36:59Z
No. of bitstreams: 1
DISSERTA??O Caroline Azevedo.pdf: 6819246 bytes, checksum: 83f9a02899ec9f2217a162e5e3f6458a (MD5) / Made available in DSpace on 2018-07-16T19:36:59Z (GMT). No. of bitstreams: 1
DISSERTA??O Caroline Azevedo.pdf: 6819246 bytes, checksum: 83f9a02899ec9f2217a162e5e3f6458a (MD5)
Previous issue date: 2017-04-24 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / The intensification of work is seen to be an ongoing concept, mainly for methodological complexity involved attempting to solidify theoretical basis capable ofassessing and measuring issues related to work demands on physical, psychological and emotional areas. Thus, this essay aims: to analyze the relationship between intensification of work and CMD in teachers from a public university in Bahia; to establish indicators for intensified work in university teaching; and to assess associated factors regarding intensification of work amongteachers from a public university in Bahia. It consists of four scientific articles: 1- Reflections on teachers? health in the context of commodification of higher education; 2- Intensified work among higher education teachers: construction of measurement indicators; 3- Caracterization of intensified work among teachers at a public university in Brazil ; 4- Association between intensified work and common mental disorders in teachers. Taking into consideration the high number of academic productivity, accounted for the material and immaterial workday combined with the set of relationships established on the work environment are conditions that may cause illnesses and/or worsen the workers? health. Common Mental Disorders are presented as potentialillnesses in face of the intensified work. This is anepidemiologic cross-sectional study performed by collecting data through a self-administered structured questionnaireapplied to representative samples of randomly selected university teacher. Regarding the association assessment, the CMD?s are considered to be variable outcomes. The present study may identifyindicators of work intensification in university teaching, contributing to produce empirical evidences and possible relevant analysis. Therefore, this survey may give supportto health and safety measures for such professionals, besides promoting changing actions in the university work context. / O trabalho intensificado se configura como um conceito em constru??o, principalmente pela complexidade metodol?gica envolvida na tentativa de solidificar embasamento te?rico capaz de avaliar e mensurar quest?es ligadas as exig?ncias do trabalho na esfera f?sica, ps?quica e emocional. Desse modo, esta disserta??o teve como objetivos: analisar a rela??o entre trabalho intensificado e TMC em docentes de uma universidade p?blica na Bahia; estabelecer indicadores do trabalho intensificado na doc?ncia universit?ria; e avaliar fatores associados diante da intensifica??o do trabalho entre docentes de uma universidade p?blica na Bahia. Para tanto, se constitui de quatro artigos cient?ficos: 1- Reflex?es sobre a sa?de docente no contexto de mercantiliza??o do ensino superior; 2- Trabalho intensificado entre docentes de ensino superior: constru??o de indicadores de mensura??o; 3- Caracteriza??o do Trabalho Intensificado entre docentes de uma Universidade P?blica na Bahia; 4- Associa??o entre trabalho intensificado e transtornos Mentais comuns em docentes. Considera-se que a elevada demanda da produtividade acad?mica, contabilizada pela jornada de trabalho material e imaterial somadas ao conjunto de rela??es estabelecidas no ambiente de trabalho s?o condi??es que podem ocasionar doen?as e/ ou agravos ? sa?de destes trabalhadores. Dentre esses agravos, os Transtornos Mentais Comuns apresentam-se como um potencial de adoecimento diante do trabalho intensificado. Este estudo epidemiol?gico do tipo corte transversal, foi realizado por meio da aplica??o e um question?rio estruturado/autoaplic?vel, em uma amostra representativa dos professores da universidade selecionada por procedimentos aleat?rios. Para avalia??o da associa??o, em quest?o, ser?o considerados como vari?vel desfecho os TMC e como vari?vel de exposi??o do trabalho intensificado. Espera-se que o presente estuo possa identificar indicadores de trabalho intensificado na doc?ncia universit?ria, contribuindo para produzir evid?ncias emp?ricas e an?lise de poss?veis impactos. Desse modo, esta pesquisa pode subsidiar medidas de prote??o ? sa?de destes profissionais e oferecer suporte para a??es de promo??o de mudan?as no contexto do trabalho universit?rio.
|
188 |
PRECARIZAÇÃO DAS CONDIÇÕES DE TRABALHO DOS PROFESSORES DO ENSINO FUNDAMENTAL DA REDE ESTADUAL DE GOIÁS.Carvalho, Carlos Marcelo Martins 04 April 2014 (has links)
Made available in DSpace on 2016-07-27T13:53:11Z (GMT). No. of bitstreams: 1
CARLOS MARCELO MARTINS CARVALHO.pdf: 5046171 bytes, checksum: 8cff3cd9d68abab96731d6c464ebc28d (MD5)
Previous issue date: 2014-04-04 / The central problem of this research is that over the years, following the changes in the
democratization of access to basic education, there was a process of casualization and
intensification of the work of elementary school teacher network state of Goiás this
perspective, it is assumed that this casualization and intensification are from the omission of
the State and education policy to offer quality education coupled with the modernization of
public educational systems through reforms that are arising from the modernization of the
production system, as a consequence, has passed a profound way in teaching, both teachers
work more flexible, as in the work of official teachers. The justification for plunging a study
like this is that this research has scientific and policy relevance, as it is fundamental role of
scientific knowledge, to understand, interpret and analyze social phenomena experienced by
different social classes and categories in society. The objective of this study is to collect data
for understanding and analyzing the process of casualization of labor and effective elementary
school teachers from the state system, in Goiás material conditions The theoretical framework
we used was: ANTUNES (2005); AZEVEDO (1997); BIANCHETTI (1999); BUFFA (2002);
CORIAT (1988); COUTINHO (1996); FRIGOTTO (2010); GHIRALDELLI (2003);
GRAMSCI (1979); IANNI (2013); LIBÂNEO (2003); MARX (1982); MESZÁROS (2006);
OLIVEIRA (2004); PARO (2008); SAVIANI (2012); among others. The methodology that
was used to conduct this study is qualitative, work with the universe of meanings, motives,
aspirations, values, worldviews and attitudes of the subjects studied. But we also use
methodologies that allowed up quantitative data such as questionnaires , charts , tables ,
captions , to interpret and quantify What is the average number of students per classroom;
How many hours daily on average are used at home with tasks , planning and correction
activity; what the workday; How many schools the teacher works; How many daily, among
others. We use various techniques such as field observation, survey of documentary material,
sound recordings, structured and semi-structured interviews. Our research identified that there
is large number of students per classroom; Degrading material conditions of operation of the
school for the development of the learning process; Precarious little training and professional
qualification; Low wages, high turnover of temporary teachers; flexible contracts without
guarantee of rights, physical and mental wear imposed by work overload to teachers
professional. We also identified that the State Government to institutionalize the
precariousness of teaching seeks ways to conserve or rationalize labor costs in the
management of public funds. / O problema central dessa pesquisa é que ao longo dos anos, acompanhando as mudanças na
democratização do acesso à educação básica, houve um processo de precarização e
intensificação do trabalho do professor do ensino fundamental da rede estadual de Goiás. Nesta
perspectiva, pressupõe-se que essa precarização e intensificação são oriundas da omissão do
Estado e das políticas educacionais em oferecer educação de qualidade aliada à modernização
dos sistemas educacionais públicos através de reformas que são resultantes da modernização do
sistema produtivo, como conseqüência, tem repercutido de maneira profunda no trabalho
docente, tanto no trabalho de professores flexibilizados, quanto no trabalho de professores
concursados. A justificativa ao aprofundar um estudo como esse é de que a presente pesquisa
possui relevância científica e política, à medida que é papel fundamental do conhecimento
científico, o de analisar, compreender, e interpretar os fenômenos sociais vivenciados pelas
diferentes classes sociais e categorias na sociedade. O objetivo deste trabalho é levantar dados
que permitam compreender e analisar o processo de precarização das condições efetivas e
materiais de trabalho dos professores do ensino fundamental da rede estadual, em Goiás. O
referencial teórico utilizado baseado nos autores: ANTUNES (2005); AZEVEDO (1997);
BIANCHETTI (1999); BUFFA (2002); CORIAT (1988); COUTINHO (1996); FRIGOTTO
(2010); GHIRALDELLI (2003); GRAMSCI (1979); IANNI (2013); LIBÂNEO (2003); MARX
(1982); MESZÁROS (2006); OLIVEIRA (2004); PARO (2008); SAVIANI (2012); entre
outros. A metodologia utilizada para realização desse estudo é de caráter qualitativo, ou seja,
trabalhamos com o universo de significados, motivos, aspirações, valores, visões de mundo e
atitudes dos sujeitos pesquisados. Mas utilizamos também metodologias que permitiram
levantar dados quantitativos como, questionários, gráficos; tabelas; legendas; para interpretar e
quantificar: Quantas horas diariamente em média são usadas em casa com tarefas, planejamento
e correção de atividade; Qual a jornada de trabalho; Em quantas escolas o professor trabalha;
Quantos diários de classe; entre outros. Utilizamos técnicas, como observação de campo,
levantamento de material documental, gravações sonoras, entrevistas estruturadas e semiestruturadas.
A nossa pesquisa identificou que existe elevado número de alunos por sala de
aula; degradantes condições materiais de funcionamento da escola para o desenvolvimento do
processo ensino aprendizagem; precária formação e pouca qualificação dos profissionais;
baixos salários; grande rotatividade de professores temporários; contratos flexíveis sem garantia
de direitos; desgaste físico e psíquico imposto pela sobrecarga de trabalho aos profissionais
docentes. Identificamos também que o Governo Estadual ao institucionalizar a precariedade do
trabalho docente busca formas de economizar ou racionalizar os custos do trabalho na gestão do
erário público.
|
189 |
Model-based approach for maize yield gap analysis related to climate variability and nitrogen management / Abordagem baseada em simulações para análise de yield gaps da cultura do milho relacionados à variabilidade climática e manejo de nitrogênioAndréa, Maria Carolina da Silva 30 August 2016 (has links)
To achieve food security and meet environmental requirements, the average rates of major crop yields in crops such as maize are expected to increase instead of expansion of cultivated areas. Maize crop has as main factors responsible for the low yields in Brazil the water and nitrogen (N) deficits. The concept of yield gaps is the difference between the maximum yield that can be achieved in a given place, limited by water (Yw) or not (Yp), and the average yields, observed under practical conditions (Ya). This concept is of great importance for characterizing the range of maximum yields and definemanagement strategies to its mitigation. Yield potential (Yp) is determined by conditions of temperature, solar radiation, photoperiod and genetic potential; to Water-limited yield (Yw) is added the water limitation imposed by crops on rainfed condition. In this study we aimed to characterize the variability of yield gaps related to environmental and management conditions; and to evaluate the economic and energy returns related to management of these yield gaps through the mechanical application of nitrogen fertilizer in six regions located in the South Central portion of the country in two periods of maize cultivation (1st and 2nd maize growing seasons). Yield gaps related to water restriction (CYg = Yp - Yw) and imposed by management conditions (MYg = Yw - Ya) were determined through aid of integrated models DSSAT system (Decision Suport System for Agrotechnology Transfer). The maize model (CSM CERES-MAIZE) was calibrated with cultivars trial data obtained for the last few years in all evaluated regions. In the 1st growing season, Yp was higher and Yw was higher and more variable than on 2nd growing season due to climate variability. The yield gaps relative to management were more limiting than the gaps relative to water deficit in almost all the evaluated regions. In both crops\' growing seasons, higher and lower MYg were found in two regions of Southern and Midwestern portion of the country, respectively. Although both regions presented high average yields (Ya), different environmental conditions determined the largest absolute differences between their rates of Yp, Yw and MYg. When assessing the profitability (R$ k g-1, MJ kg-1, R $ ha-1; MJ ha-1) of N application as MYg reduction strategy, the behavior of the variation in yields with increasing rate of N was observed. In general, the diminishing returns showed higher use efficiency (per harvested yield and per unit area) at lower N rates (20-80 kg ha-1). Economic and energy profits (regardless of their rate of change related to the increased application of cost) were found at higher N rates (90-400 kg ha-1), and this limit is directly influenced by local climate conditions. Local management of MYg can be more or less viable depending on the combination of environmental conditions and usual management conditions. In general, the cost of N application is higher in 2nd growing season due to most limiting climatic conditions, but regions with efficient management of yield gapswere alsofound in 2nd growing season / Para alcançar a segurança alimentar e atender necessidades ambientais, os índices médios de produtividade de importantes culturas na alimentação como a do milho devem aumentar em detrimento da expansão de áreas cultivadas. A cultura do milho possui como principais fatores responsáveis pelos baixos índices de produtividade no Brasil os deficits hídrico e de nitrogênio (N). O conceito de quebra de produtividade (yield gaps) é a diferença entre a máxima produtividade que pode ser atingida em dado local, seja ela limitada pela água (Yw) ou não (Yp), e a produtividade média observada em condições práticas (Ya). Esse conceito é de grande importância para caracterização de limites de alcance de máximas produtividades e definição de estratégias de manejo para mitigação dos mesmos. A produtividade potencial (Yp) é aquela determinada pelas condições de temperatura, radiação solar, fotoperíodo e potencial genético; à produtividade limitada pela água (Yw) adiciona-se a limitação hídrica imposta por cultivos em sequeiro. Nesse estudo buscou-se caracterizara variabilidade das quebras de produtividade referentes às condições ambientais e de manejo; bem como avaliar o retorno econômico e energético do manejo dessas quebras por meio da aplicação mecanizada de fertilizante nitrogenado em seis municípios localizados na região Centro-Sul do país nas duas épocas de cultivo da cultura do milho (safra e safrinha). Quebras de produtividade referentes à restrição hídrica (CYg = Yp - Yw) e impostos pelas condições de manejo (MYg =Yw - Ya) foram determinadas com auxílio da utilização do sistema de modelos integrados DSSAT (Decision Suport System for Agrotechnology Transfer).O modelo da cultura do milho (CSM CERES-MAIZE) foi calibrado com dados de ensaio de cultivares, obtidos para os últimos anos em todas as regiões avaliadas. Na 1ª safra, os indices de Yp foram mais altos e os indices de Yw foram mais altos e variáveis devido à variabilidade climática.A quebra de produtividade relativa ao manejo foi mais limitante do que a quebra relativa ao deficit hídrico em quase todos os municípios avaliados. Em ambas as safras de cultivo, maiores e menores MYg foram encontrados em dois municípios das regiões Sul e Centro-Oeste do país, respectivamente. Apesar de ambas as regiões apresentarem altas produtividades medias (Ya), diferentes condições ambientais determinaram as maiores diferenças absolutas entre seus indices de Yp, Yw e MYg. Ao avaliar a rentabilidade (R$ kg-1; MJ kg-1; R$ ha-1; MJ ha-1) da aplicação de N como estratégia de redução de MYg, observou-se o comportamento da variação dos rendimentos de produtividade com o aumento das doses de N. Em termos gerais, os rendimentos decrescentes apresentaram maior eficiência de uso do insumo (por massa colhida e por unidade de área) nas menores doses de N (20-80 kg ha-1). Lucros econômicos e energéticos (sem considerar sua taxa de variação com relação ao aumento do custo de aplicação) foram encontrados até doses mais altas de N (90-400 kg ha-1), sendo que esse limite é diretamente influenciado pelas condições climáticas locais. O manejo local dos MYg pode ser mais ou menos viável em função da combinação das condições ambientais e de manejo usual locais. Em termos gerais, o custo de aplicação de N é maior na 2ª safra devido às condições climáticas mais limitantes, porém municípios com manejo eficiente da quebra de produtividade foram encontrados mesmo nas condições de cultivo do milho safrinha.
|
190 |
Renewable liquid transport fuels from microbes and waste resourcesJenkins, Rhodri January 2015 (has links)
In order to satisfy the global requirement for transport fuel sustainably, renewable liquid biofuels must be developed. Currently, two biofuels dominate the market; bioethanol for spark ignition and biodiesel for compression ignition engines. However, both fuels exhibit technical issues such as low energy density, poor low temperature performance and poor stability. In addition, bioethanol and biodiesel sourced from first generation feedstocks use arable land in competition with food production, and can only meet a fraction of the current demand. To address these issues it is vital that biofuels be developed from truly sustainable sources, such as lignocellulosic waste resources, and possess improved physical properties. To improve and control the physical properties of a fuel for specific application, one must be able to tailor the products formed in its production process. All studies within this thesis, therefore, have the aim of assessing the fuels produced for their variability in physical property, or the aim of directing the process considered to specific fuel molecules. In Chapter 2, spent coffee grounds from a range of geographical locations, bean types and brewing processes were assessed as a potential feedstock for biodiesel production. While the lipid yield was comparable to that of conventional biodiesel sources, the fatty acid profile remained constant irrespective of the coffee source. Despite this lack of variation, the fuel properties varied widely, presumably due to a range of alternative biomolecules present in the lipid. Though coffee biodiesel was produced from a waste product, the fuel properties were found to be akin to palm oil biodiesel, with a high viscosity and pour point. The blend level would therefore be restricted. In Chapter 3 the coffee lipid, as well as a range of microbial oils potentially derived from renewable sources were transformed into a novel aviation and road transport fuel through cross-metathesis with ethene. Hoveyda-Grubbs 2nd generation catalyst was found to be the most suitable, achieving 41% terminal bond selectivity under optimum conditions. Metathesis yielded three fractions: an alkene hydrocarbon fraction suitable for aviation, a shorter chain triglyceride fraction that upon transesterification produced a short chain biodiesel fuel, and a multifunctional volatile alkene fraction that could potentially have application in the polymer industry. Though there was variation for the road transport fuel fraction due to the presence of long chain saturates, the compounds fell within the US standard for biodiesel. The aviation fraction lowered the viscosity, increased the energy density, and remained soluble with Jet A-1 down to the required freezing point. Oleaginous organisms generally only produce a maximum of 40% lipid, leaving a large portion of fermentable biomass. In Chapter 4, a variety of ethyl and butyl esters of organic acids – potentially obtainable from fermentation – were assessed for their suitability as fuels in comparison to bioethanol. One product, butyl butyrate, was deemed suitable as a Jet A-1 replacement while four products, diethyl succinate, dibutyl succinate, dibutyl fumarate and dibutyl malonate, were considered as potential blending agents for diesel. Diethyl succinate, being the most economically viable of the four, was chosen for an on-engine test using a 20 vol% blend of DES (DES 20) on a chassis dynamometer under pseudo-steady state conditions. DES20 was found to cause an increase in fuel demand and NOx emissions, and a decrease in exhaust temperature, wheel force, and CO emissions. While fermentation is generally directed to one product, producing unimolecular fuels, they do not convert the entirety of the biomass available. An alternative chemical transformation is pyrolysis. In Chapter 5, zeolite-catalysed fast pyrolysis of a model compound representative of the ketonic portion of biomass pyrolysis vapour – mesityl oxide – was carried out. The aim of this study was to understand the mechanistic changes that occur, which could lead to improved bio-oil yields and more directed fuel properties of the pyrolysis oil. While HZSM-5 and Cu ZSM-5 showed no activity for hydrogenation and little activity for oligomerisation, Pd ZSM-5 led to near-complete selective hydrogenation of mesityl oxide to methyl isobutyl ketone, though this reduced at higher temperatures. At lower temperature (150-250 °C), a small amount of useful oligomerisation was observed, which could potentially lead to a selective pyrolysis oligomerisation reaction pathway.
|
Page generated in 0.14 seconds