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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.
231

Avaliação de diferentes dietas líquidas associadas ao enriquecimento ambiental no desempenho e comportamento de bezerros leiteiros / Avaliation of diferents liquid diets associated to environmental enrichiment on performance and behaviour of dairy calves

Silva, Marcos Donizete da 09 November 2018 (has links)
O objetivo deste trabalho foi avaliar o efeito de duas dietas líquidas , associadas ao uso de enriquecimento ambiental (EA) em bezerros alojados individualmente. O delineamento experimental foi um fatorial 2 x 2, sendo avaliadas duas dietas líquidas (leite ou sucedâneo lácteo) e ausência ou presença de EA (bico de mamadeira e coçador). Foram utilizados 24 bezerros recém-nascidos da raça Holandês, distribuidos em 4 tratamentos: Leite, Leite + EA, Sucedâneo, Sucedâneo + EA. O sucedâneo lácteo continha em sua composição 22,33 % PB, 15,96% EE e 1,07% de FDN, na matéria seca, e foi diluído para uma concentração de 14% de sólidos. O leite apresentava 3,37% PB, 3,38% EE na matéria seca e 12,25% de sólidos. Os animais foram alojados em abrigos individuais e tinham livre acesso a água e ao concentrado. Foi utilizado um programa alimentar step up/step down, com desaleitamento realizado aos 56 dias de vida. Não houve efeito da associação das diferentes dietas líquidas com EA sobre o desempenho dos animais (P>0,05), mas houve tendência (P<0,082) de redução do consumo de concentrado para animais com acesso ao EA. O desempenho animal foi sigificativamente afetado pelo fator idade (P<0,05). A associação de dieta líquida com EA não afetou os parâmetros metabólicos, mas animais aleitados com leite apresentaram maiores concentrações de B-Hidroxibutirato e ureia plasmática (P>0,05). Da mesma forma, a combinação de dietas com EA não afetou o escore fecal, mas animais aleitados com sucedâneo apresentaram fezes mais fluidas (P>0,05). Não houve alteração no repertório comportamental dos animais em função de diferentes dietas líquidas associadas ao EA (P>0,05). Durante o período de avaliação de duas horas após o aleitamento da manhã, os animais passaram a maior parte do tempo em ócio (60%), seja em pé ou deitado. Os outros 40% do tempo foram gastos com atividades relacionadas a alimentação, como pastejando (8,5%), consumindo concentrado (3,8%); atividades fisiológicas, como dormindo (5,45%), ruminando (1,3%), defecando (0,6%), urinando (0,1%); ou ainda atividades comportamentais, como explorando o ambiente (6,3%) e se lambendo (6,7%). Os animais utilizaram o EA por aproximadamente 1,4% do tempo somente e vocalizaram durante 1,7% ou realizaram mamada não nutritiva por 1,9%. Houve tendência (P<0,0627) para redução na vocalização e função da disponibilidade de EA. O fornecimento de diferentes dietas líquidas associadas ou não ao EA não afetaram o desempenho, metabolismo ou comportamento animal. No entanto, não se descarta a possibilidade de ganhos no bem-estar dos animais com o uso de enriquecimento ambiental uma vez que, os animais vocalizam menos durante o processo de desaleitamento. / The objective of this study was to evaluate the effect of two liquid diets, associated to the use of environmental enrichment (EE) in individually housed calves. For the evaluation a 2 x 2 factorial experimental design, with two liquid diets (milk or milk replacer) and absence or presence of EE (bottle nipple and scraper) evaluated. Twenty-four newborn Holstein calves were distributed in to four treatments: Milk, Milk + EE, Milk replacer, Milk replacer + EE. The milk replacer contained 22.33% CP, 15.96% EE and 1.07% NDF, in the dry matter, and was diluted to a concentration of 14% solids. The milk presented 3.37% CP, 3.38 EE in the dry matter and 12, 25% solids. The animals were housed in individual shelters and had free access to water and concentrate. A step up/step down diet program was used, with weaning performed at 56 days of age. There was no effect of the association of different liquid diets with EA on the performance of the animals (P> 0.05), but there was a tendency (P <0.082) to reduce the concentrate intake for animals with access to EE. The animal performance parameters were significantly affected by the age factor (P<0.05). The association of liquid diet with EE did not affect metabolic parameters, but milk-fed animals had higher concentrations of B-Hydroxybutyrate and plasma urea-N (P>0.05). Likewise, the combination of liquid diets with EE did not affect fecal score, but animals fed with milk replacer had more fluid faeces (P>0.05). There was no change in the behavioral repertoire of the animals as a function of liquid diets associated with EA (P> 0.05). During the two-hour evaluation period after liquid diet feeding, the animals spent most of their time in leisure (60%), either standing or laying down. The other 40% of the time was spent on feeding related activities such as grazing (8.5%), consuming concentrate (3.8%); physiological activities, such as sleeping (5.45%), ruminating (1.3%), defecating (0.6%), urinating (0.1%); or behavioral activities, such as exploring the environment (6.3%) and self-grooming (6.7%). The animals used the EE for approximately 1.4% of the time only, and vocalized for 1.7% or performed non-nutritive feeding for 1.9%. There was a trend (P <0.0627) for reduction in vocalization and function of EE availability. Feeding different liquid diets associated or not with EA did not affect performance, metabolic or animal behavior. However, the possibility of improved animal welfare with the use of environmental enrichment is not ruled out since the animals vocalize less during the process of weaning.
232

Efeitos do enriquecimento ambiental na neuropatia periférica induzida em ratos. / Effects of environmental enrichment on peripheral neuropathy induced in rats.

Vieira, Louise Faggionato Kimura 10 May 2018 (has links)
O enriquecimento ambiental (EA) é capaz de alterar a percepção a estímulos nociceptivos, bem como de aumentar a resposta analgésica induzida por opioides. Considerando que a dor neuropática é um grave problema de saúde pública e o tratamento para esta condição ainda é insatisfatório e acarreta efeitos adversos severos, os objetivos deste trabalho foram avaliar a interferência do bem-estar animal na sensibilidade dolorosa de ratos frente a diferentes estímulos nociceptivos e investigar possíveis mecanismos envolvidos neste efeito. Os animais foram submetidos à avaliação da ansiedade e da sensibilidade dolorosa, em modelo de neuropática, frente a estímulos nociceptivos mecânicos e térmicos. Foi verificado que um protocolo de EA elaborado e iniciado desde o nascimento foi capaz de reverter totalmente a dor neuropática de animais submetidos à constrição crônica do nervo isquiático (CCI). Este efeito foi completamente abolido quando os animais enriquecidos foram tratados com naloxona, um antagonista opioide não seletivo. Análises de Western Blot não mostraram diferenças na expressão de receptores opioides em regiões relacionadas ao processamento e controle da dor, porém os níveis circulantes de beta-endorfina e met-encefalina aumentaram na presença de dor crônica nos animais enriquecidos. Os níveis séricos de corticosterona também se apresentaram aumentados nos animais com EA, independentemente da neuropatia, mas o tratamento com mifepristona, um antagonista de receptores de glicocorticoides, não alterou a analgesia dos animais operados. Ainda, o EA também reduziu a imunorreatividade para serotonina na medula espinal de animais com CCI. Além do efeito analgésico, o EA também reduziu o marcador de lesão neuronal ATF-3 no gânglio da raiz dorsal e, no local da constrição, reduziu a degeneração neuronal característica do modelo, induzindo ainda, a presença predominantemente de macrófagos do tipo M2. Este trabalho reforça a importância do bem-estar na prevenção do desenvolvimento da dor neuropática e mostra uma abordagem não farmacológica que pode aumentar a resiliência de animais contra estímulos nocivos. / Environmental enrichment (EE) is capable of altering the perception of nociceptive stimuli, as well as increasing the analgesic response induced by opioids. Considering that neuropathic pain is a serious public health problem and the treatment for this condition is still unsatisfactory and induces severe side effects, the aims of this study were to evaluate the interference of animal welfare in the sensitivity to different nociceptive stimuli and to investigate possible mechanisms involved in this effect. Animals were submitted to the evaluation of anxiety and pain sensitivity in a model of neuropathic pain, against mechanical and thermal nociceptive stimuli. It was seen that an elaborated EE starting from birth was able to totally reverse the neuropathic pain of animals submitted to chronic constriction injury of the sciatic nerve (CCI). This effect was completely abolished when enriched animals were treated with naloxone, a nonselective opioid antagonist. Western blot analysis did not show differences in opioid receptor expression in regions related to pain processing and control, however, circulating levels of beta-endorphin and met-enkephalin were increased in the presence of chronic pain in enriched animals. Serum corticosterone levels were also increased in animals with EE regardless of neuropathy, but treatment with mifepristone, a nonselective glucocorticoid receptor antagonist, did not alter the analgesia of operated animals. Moreover, EE reduced serotonin immunoreactivity in the spinal cord of CCI animals. In addition to analgesic effect, EE also reduced the neuronal injury marker ATF-3 at the dorsal root ganglia and, at the site of constriction, decreased the neuronal degeneration characteristic of the model, inducing the presence of M2 macrophages subtype predominantly. This work reinforces the importance of well-being in preventing the development of neuropathic pain and shows a non-pharmacological approach that may increase animal resilience against noxious stimuli.
233

Aplicação de nanopartículas superparamagnéticas na tecnologia de terras raras / Superparamagnetic nanoparticles in rare earth technology

Almeida, Sabrina da Nóbrega 19 October 2018 (has links)
As Terras Raras (TRs), particularmente a série dos lantanídios, são consideradas elementos estratégicos da tecnologia moderna devido ao seu papel essencial na catálise petroquímica, lasers, materiais luminescentes, e na fabricação de superimãs necessários para conversão de energia em carros elétricos e geradores eólicos. Atualmente, o comércio internacional de TRs é dominado pela China (> 90%). O Brasil apresenta um enorme potencial em termos de reservas de TRs, mas o país ainda carece de uma tecnologia competitiva para o processamento mineral, incluindo a separação e produção de elementos. Processos hidrometalúrgicos baseados na extração por solvente e troca iônica são normalmente empregados pelos produtores, mas os processos são bastante caros e poluentes, envolvendo centenas de reatores e colunas para superar as propriedades químicas muito similares dos elementos. Esta tese relata uma tecnologia alternativa verde chamada Nanohidrometalurgia Magnética (NHMM), que faz parte dos nossos esforços para introduzir a nanotecnologia na área mineral. A tecnologia é baseada em nanopartículas superparamagnéticas, previamente projetadas com um revestimento protetor e um agente complexante específico, como o DTPA, para sequestrar os elementos estratégicos da solução lixiviada. NHMM permite a captura e processamento de elementos metálicos diretamente a partir de solução aquosa, sem empregar solventes orgânicos. Depois de confinar o elemento com o uso de um ímã externo (Nd2Fe14B), ele pode ser facilmente separado da mistura e liberado pela aplicação de condições ácidas leves, enquanto as nanopartículas magnéticas retornam ao processo, para um novo procedimento em lote. Na escala laboratorial, todo o procedimento pode ser realizado no mesmo reator, cumprindo, além das instalações de processamento e recuperação, os requisitos mais importantes da Química Verde. Esta tese foi concentrada na extração e separação de elementos de lantanídios da monazita. Um estudo detalhado termodinâmico e cinético foi realizado para compreender o processo. O intrigante comportamento magnético das nanopartículas magnéticas revestidas de lantanídios também foi investigado, fornecendo um ensaio crítico de seu comportamento magnetoforético em solução aquosa. O comportamento magnetoforético das nanopartículas superparamagnéticas permitiu monitorar sua interação direta com os íons lantanídeos, ilustrando uma nova perspectiva no processo de separação. / Rare earths (RE), particularly the lanthanide series, are considered strategic elements in modern technology because of their essential role in petrochemical catalysis, lasers, luminescent materials, and in the fabrication of strong magnets required for energy conversion in electric cars and aeolic generators. Currently, the international RE commerce is dominated by China (> 90%). Brazil exhibits a huge potential in terms of RE reserves but the country still lacks a competitive technology for mineral processing, including the element separation and production. Hydrometallurgy processes based on solvent extraction and ionic exchange are normally employed by the producers, but the processes are rather expensive and polluting, involving hundred reactors and columns to overcome the challenge of dealing with elements exhibiting very similar chemical properties. This thesis reports an alternative green technology named Magnetic Nanohydrometallurgy (MNHM), reinforcing our attempts and efforts to introduce Nanotechnology in the mineral area. The MNHM technology is based on superparamagnetic nanoparticles, previously engineered with a protecting coating and a specific complexing agent, such as DTPA, for sequestering the strategic elements from the lixivia solution. MNHM allows the capture and processing of metal elements directly from aqueous solution, without employing organic solvents. After confining the element with the use of an external magnet (Nd2Fe14B), it can be easily separated from the mixture, and released by applying mild acidic conditions, while the magnetic nanoparticles return to the process, for a new batch procedure. At the laboratory scale, the entire procedure can be performed in the same reactor, fulfilling, in addition to the processing and recovery facilities, the most important requisites of Green Chemistry. This thesis was concentrated on the extraction and separation of lanthanide elements from monazite. A detailed thermodynamic and kinetic study was carried out to support the ideas, leading to a new separation technology, capable of obtaining and processing the lanthanides under green and sustainable conditions. The magnetophoretic behavior of the superparamagnetic nanoparticles allowed to monitor their direct interaction with the lanthanide ions, illustrating a new perspective in the separation process.
234

Efeito protetor do enriquecimento ambiental na manifestação tardia da ansiedade e do déficit de extinção da memória de medo induzidos por estresse agudo em ratos: o papel da sinalização de glicocorticoide no complexo basolateral da amígdala. / Environmental enrichment protection on acute stress-induced late anxiety-like behavior and fear extinction impairment in rats: role of glucocorticoid receptor signaling in the basolateral nucleus of amygdala.

Novaes, Leonardo Santana 21 June 2018 (has links)
As consequências de eventos estressantes sobre a saúde humana, principalmente relacionada à condição psiquiátrica, tem ganhado notoriedade nos últimos anos em decorrência do crescente número de comorbidades associadas ao estresse registradas nas grandes cidades. Transtornos emocionais relacionados a sintomas de ansiedade são comuns dentre os relatados na clínica psiquiátrica e ganham importância em trabalhos científicos devotados ao estresse, que lançam mão de abordagens diversas para compreender os mecanismos neurobiológicos subjacentes à a persistência de sintomas ansiosos decorrentes de um evento estressante. Trabalhos prévios mostraram que tanto o estresse agudo de contenção quanto a administração sistêmica de corticosterona (CORT, hormônio glicocorticoide murino) promovem, 10 dias depois, comportamento do tipo ansioso e remodelamento dendrítico no complexo basolateral da amígdala (BLA) em ratos. Além disso, alguns trabalhos recentes mostraram que a exposição ao enriquecimento ambiental (EA) reverteu o efeito ansiogênico e sobre a modulação dendrítica do BLA induzidos por estresse repetido. Em trabalho recente, nós verificamos que o EA preveniu o efeito ansiogênico imediato do estresse agudo de contenção. Esse efeito protetor do EA pareceu estar relacionado a seu efeito preventivo no aumento da atividade neuronal e do receptor de glicocorticoide (GR) no BLA. No presente trabalho, nós verificamos que o EA preveniu tanto o surgimento do comportamento do tipo ansioso quanto o déficit de extinção da memória de medo induzidos por estresse agudo de contenção verificados 10 dias depois. Porém, não está claro se esses efeitos estão relacionados com alterações na árvore dendrítica do BLA e/ou com a atividade de GR no mesmo núcleo. Dessa forma, um dos objetivos centrais do trabalho foi determinar se o efeito preventivo do EA na persistência das alterações comportamentais, e nas alterações morfológicos no BLA, induzidas por estresse agudo, são atribuidas às ações de CORT. Nós observamos que o efeito preventivo do EA na ansiedade e no déficit de extinção, verificados 10 dias após o estresse, não estão relacionados à prevenção no aumento da densidade de espinhos dendríticos do BLA. Além disso, ainibição da síntese de CORT por metirapona preveniu a emergência do comportamento do tipo ansioso 10 dias após o estresse, indicando que a sinalização desse hormônio é crucial para os efeitos comportamentais tardios relacionados ao estresse agudo. Finalmente, lançando mão do uso da tecnologia do DNA recombinante, nós verificamos que a inibição da atividade genômicoa de GR no BLA preveniu o comportamento do tipo ansioso manifestado 10 dias após o estresse. / The consequences of stressful events on human health, especially related to psychiatric disorders, have gained attention in recent years due the increasing number of comorbidities associated to stress in large cities. Anxiety-related disorders are common among the psychiatric patients and are widely present in studies devoted to stress, which use different approaches to investigate the neurobiological mechanisms underlying the persistence of anxiety symptoms caused by a stressful event. Either acute restraint stress or systemic injection of corticosterone (CORT, a rodent glucocorticoid) in rats leads to enhanced anxiety-like behavior and dendritic branch remodeling in the basolateral amygdala complex (BLA) 10 days later. Also, some studies showed that exposure to environmental enrichment (EE) reverted the long- lasting anxiety-like behavior and the repeated stress-induced BLA dendritic hypertrophy in rats. In a recent study, we found that EE prevented anxiety-related behavior in adult rats observed immediately after acute restraint stress. This protective role of EE appears to be due to the prevention of the stress-induced increase in neuronal activity and in glucocorticoid receptor (GR) nuclear activity in the BLA. In this study, we showed that EE prevented the restraint stress-induced long-lasting anxiety and contextual fear extinction impairment in adult rats. However, it is not yet clear if this protective role of EE is related to changes in the dendritic branch and/or in the GR signaling in the BLA. The present study sought to determine whether the preventive effect of EE on persistent stress-related changes in behavior as well as in the BLA morphology and activity are attributed to CORT signaling. We found that the EE- induced protection on anxiety-like behavior and fear extinction impairment 10 days after acute restraint stress was not related to prevention of the increase in spine density in BLA. Moreover, systemic injection of GC synthesis inhibitor (metyrapone) prevented the anxiety-like behavior 10 days after stress, showing that GC signaling during stress is crucial to late stress-related behavior. Finally, by antagonizing the genomic signaling of the endogenous GR in the BLA, through the use of recombinant DNA technology, we prevented the emergence of anxiety-related behavior 10 days after acute stress.
235

Efeitos do enriquecimento ambiental e da oxitocina sobre o consumo de etanol em camundongos C57BL/6 submetidos ao estresse agudo. / Effects of environmental enrichment and oxytocin on ethanol intake in C57BL/6 mice after an acute stress.

Almeida, Marina Gomes de 04 December 2018 (has links)
O etanol é a droga de abuso mais consumida em todo o mundo. Frequentemente, há comorbidade entre o alcoolismo e transtornos relacionados ao estresse. O enriquecimento ambiental (EA) reduz o comportamento ansioso em resposta ao estresse e consequentemente minimiza os efeitos reforçadores de drogas de abuso. Como o enriquecimento induz interações sociais, deve promover a liberação de oxitocina (OT), um neuropeptídeo liberado em resposta a experiências sociais. A OT tem propriedades ansiolíticas que devem conferir proteção aos efeitos deletérios do estresse. Neste trabalho, verificamos se o EA ou a OT protegem contra o consumo de etanol em camundongos machos C57BL/6, mesmo após a exposição ao estresse de exposição ao predador, um modelo de transtorno de estresse pós traumático (TEPT). Para avaliar os efeitos do EA, os animais foram divididos entre caixas padrão (NE) e caixas enriquecidas (EA) após a fase de aquisição, onde permaneceram por 21 dias. Em seguida foram subdivididos em grupos não estressados (NENS e EANS) e estressados (NEST e EAST) e reexpostos novamente ao etanol por 24h após o estresse; após 7 dias, com avaliação do comportamento do tipo ansioso por Labirinto em Cruz Elevado; e após 14 dias do estresse, quando passaram pela Caixa Claro-Escuro. Dentre os animais estressados, EAST reduziu o consumo e exibiu menos comportamento de medo e ansiedade. Em outro experimento, verificamos os efeitos de diferentes doses de carbetocina (CBT), um análogo da OT, sobre a ingestão de álcool. Então, foi realizado o tratamento crônico com CBT em camundongos, sendo que um grupo recebeu salina (CTL), outro recebeu CBT 1h antes das reexposições (CBT1h) e o último recebeu CBT 16h antes das reexposições ao etanol (CBT16h). Os animais passaram pelo mesmo delineamento do experimento anterior. A CBT1h teve efeito protetor sobre o consumo de álcool após estresse, enquanto a CBT16h não. / Ethanol is the most commonly abused drug. Comorbidity between alcoholism and stress related disorders is highly frequent. Environmental enrichment (EE) reduces anxiety-like behaviour and consequently minimizes reinforcing effects of abused drugs. As EE favours social interactions, it might promote oxytocin (OT) release. OT is a neuropeptide secreted after social experiences. It is also related that OT has anxiolytic properties, which confers protection against stress maladaptive effects. The purpose of this work was to check if EE or OT protect against ethanol intake in male C57BL/6 abstinent mice even after stress exposure. To evaluate EE effects, animal were divided between standard housing (NE) and enriched housing (EA) after acquisition for 21 days. Then, both groups were subdivided into non-stressed (NENS, EANS) and stressed (NEST, EAST) and were submitted to predator exposure stress, a model of post traumatic stress disorder (PTSD). Right after stress, animals were reexposed to ethanol for 24h; after 7 days, when anxiety-like behaviour was evaluated by Elevated Plus Maze; and after 14 days of stress, when their behaviour was assessed by Light Dark Box. Among stressed animals, EAST reduced ethanol intake and exhibited decreased anxiety-like behaviour and fear. We determined the effects of different doses of carbetocin (CBT) on alcohol intake. In another experiment, mice were chronically treated CBT, an OT analogue. Control mice received saline (CTL), CBT1h were treated 1 hour before ethanol reexposure and CBT16h were treated 16 hours before reexposures. The protocol was the same of the first experiment. CBT1h protected against ethanol intake after stress, while CBT16h did not. These results show that EE buffers ethanol. CBT reduced ethanol consumption when it was administered immediately before stress.
236

Effect of sensory enrichments on the behaviour of captive Northern lynx (Lynx lynx lynx) and assessment of automated behaviour monitoring technologies

JEAN-LOUIS, Uranie January 2019 (has links)
Captive environments like zoo exhibits offer limited space, lacking many of the environmental stimuli that are present in the wild. This may reduce animal welfare and potentially lead to the development of stereotypic behaviour like pacing. Environmental enrichment is used to prevent and reduce pacing and enhance animal well-being. The aim of this project was to evaluate sensory enrichments, and the effect of such enrichment on pacing in a group of Northern lynx by means of new, automated monitoring technologies in combination with traditional visual observations. The lynxes were exposed to valerian, catnip and cinnamon as olfactory enrichment. The acoustic enrichments were play-backed mouse squeals, roe deer barking and lynx vocalizations, and live crickets. The responses of the lynx were recorded by logging their subcutaneous HDX pit tags, and Bluetooth Low Energy (BLE) tags mounted on collars and using a wildlife camera. The results showed that catnip elicited clear “catnip responses” i.e sniffing, rubbing, biting and licking. The sounds were found to attract the lynxes and increase their arousal. One of the sounds, the lynx calls, elicited social behaviour. However, none of the sensory treatments reduced pacing. The combination of these automated technologies with visual observation was powerful to evaluate the effect of enrichment on captive lynxes and to monitor their activity patterns and stereotypic behaviours. Sensory enrichment could also be used in the wild as lures to attract lynxes to BLE or HDX PIT tag logging stations and to wildlife cameras, as part of monitoring a lynx population.
237

Efeitos comportamentais do enriquecimento ambiental de curta duração em camundongos: expressão de microRNAs e participação da via de sinalização BDNF - TrkB na sensibilização comportamental ao etanol. / Behavioral effects of short-term environmental enrichment in mice: microRNA expression and involvement of the BDNF - TrkB signaling pathway.

Rueda, André Veloso Lima 19 April 2017 (has links)
O enriquecimento ambiental (EA) reverte a sensibilização comportamental (SC) ao etanol em camundongos e diminui os níveis de BDNF no córtex pré-frontal (CPF). O objetivo deste trabalho foi estudar os efeitos do EA sobre parâmetros comportamentais, resposta de corticosterona ao estresse, expressão de microRNAS e a participação da via BDNF-TrkB no CPF frente à SC ao etanol. Camundongos mantidos em EA foram submetidos a testes comportamentais (ansiedade, depressão, anedonia e comportamentos repetitivos). Também foram tratados repetidamente com etanol e expostos ao EA para a avaliação da corticosterona plasmática e da expressão de microRNAs no CPF. A via BDNF-TrkB foi inibida no CPF de camundongos que desenvolveram a SC ao etanol. O EA diminuiu a atividade locomotora e exploratória, a ativação do eixo HPA após estresse agudo, aumentou o peso do baço e diminuiu a expressão de miR-132 e let-7d. Os resultados sugerem o envolvimento de microRNAs na reversão da SC ao etanol; contudo, a via BDNF-TrkB no CPF não parece estar diretamente envolvida neste processo. / The environmental enrichment (EE) reverts the ethanol-induced behavioral sensitization (EIBS) in mice and decreases BDNF levels in the prefrontal cortex (PFC). The aim of this work was to evaluate the effects of EE on behavioral parameters, on the corticosterone response to stress and on microRNA expression and to assess the involvement of the BDNF-TrkB pathway in the PFC on the EIBS. Mice kept in EE were submitted to behavioral tests (anxiety, depression, anhedonia and repetitive behaviors). Mice were also treated repeatedly with ethanol and exposed to EE for the assessment of plasma corticosterone levels and microRNA expression in the PFC. The BDNF-TrkB pathway was blocked in the PFC of mice that developed EIBS. EE decreased locomotion, exploratory activity and HPA axis activation after acute stress, increased spleen weight and decreased miR-132 and let-7d expression. The results suggest the involvement of microRNAs in the reversal of EIBS promoted by EE; however, the BDNF-TrkB pathway in the PFC does not seem to be directly involved in this process.
238

The difference in how UAE and EW law controls Gharar (risk) and so Riba in a construction contract in the Emirate of Dubai, UAE

Crawley, Shaun Edward January 2017 (has links)
This research critically analyses and compares how the United Arab Emirates (UAE)1 Law and English and Welsh (EW) Law regulates obligations in a contract, for a thing that is to come into existence in the future, namely a construction contract. Uncertainty/speculation as to how an obligation is to be performed in UAE Law is termed gharar. The word that is synonymous with this terminology in EW Law is “risk”. The extent of gharar or ‘risk’ (these terms are used on an interchangeable basis in this thesis) in an obligation plays a fundamental role in the profitability of a construction contract. Where losses become unacceptable, particularly for the Contractor, a dispute will arise. These circumstances may be in conflict with UAE Law, which obligates parties to a contract to ensure circulation of wealth by maintaining the anticipated profit to be made from a contract. This analysis also reviews how the level of gharar or ‘risk’ can be increased by operation of two types of provision that are included in standard forms of construction contract such as the International Federation of Consulting Engineers, Geneva, Switzerland (FIDIC) Conditions of Contract for Construction for Building and Engineering Works Designed by the Employer 1st Ed. 1999 (FIDIC99). The first is a provision that releases the Employer from liability where the Contractor does not give timely notice of an Employer’s act of prevention. The second is a provision giving the Employer a discretion to act in an opportunistic manner, and exempt or limit his liability. It considers how FIDIC99 should be applied to control gharar or ‘risk’ in a positive way. It also identifies similarities between how UAE Law controls gharar and that of the notion of parties’ reasonable expectations in contract Law (herein referred to as parties’ expectations), and how relational contracts operate to ensure parties achieve their expectations.
239

Investigation of pollution coming from copper, lead, and zinc mining, and factors controlling mobility and bioavailability of pollutants at Ecton Hill, Staffordshire, UK

Al-Ibrahim, Zahid Omar Mustafa January 2017 (has links)
Former mining areas are well-known globally to be a significant anthropogenic source of contaminants being dispersed into the surrounding environment. Various human activities, including ore mineral mining, industrial activities, domestic waste production, and the agricultural application of fertilisers and pesticides, are likely to contribute to the release of huge amounts of potentially toxic metals into the ecosystem, which have harmful effects on the flora and fauna and on human health. Therefore, the main aim of this study is to evaluate the contamination that arises from some selected heavy metals (Cu, Pb, Zn, Mn, Cr, Ni, and V) in topsoil and floodplain samples from the Ecton mining area. Ecton Hill is located in the southern part of the Peak District, Staffordshire, England, and bounded by the River Manifold from the west. This area has been mined for sulphide minerals, which were extracted extensively from the 16th century until the mid-19th century; the area is currently being used for cattle rearing and agricultural purposes. Therefore, it would be worth finding out the extent to which the area has been polluted by the aforementioned metals. To this end, topsoil and floodplain samples were collected and analysed for their total concentrations using XRF technique and different granulometric classes (i.e. clay, silt, and sand) using a (Malvern Mastersizer Long Bed) laser granulometer with a presentation unit of MS-17. In addition, soil specific factors, including organic matter content, organic carbon, pH, Eh, and cation exchange capacity were also measured. Spatial distribution maps were constructed using a GIS approach for the metals studied over the study area. Contamination and ecological risk assessments were carried out via the geoaccumulation index (Igeo) and enrichment factors (EF) respectively. Moreover, collected soils for different land uses have been assessed using the UK government soil guidelines (i.e. ICRCL and CLEA's SGVs soil values). Furthermore, the bioavailability, leachability, and fractionation (using five-steps sequential extraction) of the metals in various soil phases were characterised using correlation matrix and principal component analysis (PCA) approaches. The GIS- based spatial analysis maps reveal that elevated concentrations of the metals are located around the sites of the mining waste in the area. The contamination assessment results indicate that Cu, Pb, Zn have a contamination degree ranging between strongly contaminated (class 4) and extremely contaminated (class 6). The results of the ecological assessment by enrichment factor (EF) show that Pb has the highest enrichment factor. The bioavailability results of the heavy metals under study, via EDTA, show that Cu, Pb, Zn have the highest bioavailable fractions. The regression analysis demonstrates that Mn gives the best fit regression equation with the highest R2 value of 0.825. The leachability results reveal that, of the seven heavy metals, Zn has the highest leachable value, whereas the lowest leachable was recorded for Cr. Speciation was measured using the five-steps procedure, and the results show that Cu, Pb and Zn are mainly associated with the organic matter fraction, whilst, Cr, Ni and V are associated with the residual fraction. The principal component analysis (PCA) revealed that oxides of Fe/Al, organic matter, and the clay and silt fractions are the main soil parameters responsible for binding heavy metals to the soil surfaces of the study area. Changing the redox potential conditions and acidification was investigated and the results indicate that such changes have significant effects on the release of heavy metals from the soil particles at Ecton Hill.
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Enriquecimento de sementes de feijão e trigo com zinco através da aplicação foliar do micronutriente / Foliar application of zinc for biofortification of bean and wheat seeds

Angelini, Bruno Geraldi 18 January 2018 (has links)
Frente ao aumento populacional e consequente incremento na demanda por alimentos, é importante estabelecer um melhor aproveitamento da área de cultivo, objetivando a colheita de produtos agrícolas em maior quantidade e de melhor qualidade. O aumento da concentração de micronutrientes nos produtos colhidos, especialmente de zinco é um desafio crescente para a agricultura, com possibilidade de trazer benefícios à saúde humana e à produtividade da cultura. Nesse sentido, a aplicação foliar de zinco realizada periodicamente, à partir da antese floral, é uma técnica capaz de incrementar o teor do micronutriente nas sementes e biofortificar os grãos de feijão e trigo, causando melhoria de aspectos agronômicos (crescimento vegetativo e produtividade da cultura) de plantas provenientes dessas sementes, além de resultar proveitos para a saúde humana daqueles que se alimentam de produtos biofortificados, e ainda com potencial para produzir grãos e sementes como produtos de maior valor comercial no mercado, valendo-se de inovação tecnológica. Porém, atualmente pouco se conhece sobre os diversos aspectos desta técnica. Assim sendo, objetivou-se: (i) elucidar o efeito da aplicação foliar de zinco, à partir da antese floral, como método para incrementar o teor do micronutriente nos grãos de feijão (Phaseolus vulgaris L.) e de trigo (Triticum aestivum L.), em substrato com teor adequado do micronutriente (ii) utilização de diferentes fontes de zinco aplicadas via foliar visando estabelecer a melhor fonte para o aumento do teor do micronutriente no grão de feijoeiro e (iii) determinação das doses de zinco mais adequadas a serem aplicadas através de pulverização foliar visando o aumento do teor do nutriente no grão de plantas de feijão e de trigo. Com base nos resultados obtidos, concluiu-se que (i) a aplicação foliar de zinco realizada periodicamente, à partir da antese floral é capaz de aumentar o teor do micronutriente em grãos de feijão e de trigo; (ii) a fonte mais viável para o enriquecimento de grãos de feijão é o sulfato de zinco; (iii) e todas as doses testadas (125, 250, 375 e 500 g Zn ha-1) aplicadas via foliar na forma de sulfato de zinco foram efetivas para o enriquecimento de grãos de feijão e de trigo, em relação ao controle (0 g Zn ha-1). / In view of the population increase and consequent growth of food demand, it is important to establish a better utilization of the cultivation area, aiming the harvest of agricultural products in greater quantity and of better quality. The increased concentration of micronutrients in products harvested, especially zinc, is a growing challenge for agriculture, with potential to bring benefits to human health and crop productivity. In this matter, the foliar zinc application performed periodically starting at floral anthesis is a technique capable of increasing the micronutrient content in the seeds and biofortifying grains of common bean and wheat, causing agronomic aspects improvement (vegetative growth and crop productivity) of plants derived from these seeds, in addition to bringing benefits to human health of those who feed on biofortified products, and still with potential to produce grains and seeds as products of greater commercial value in the market, being a technological innovation. However, currently little is known about the aspects that circumvent this technique. The objective of this study was: (i) elucidate the effect of foliar application of zinc, starting at floral anthesis, as a method to increase the micronutrient content of common bean (Phaseolus vulgaris L.) and wheat (Triticum aestivum L.) (ii) the use of different sources of zinc applied in a foliar way, in order to establish the best source for increasing the micronutrient content in common bean grains, and (iii) the determination of the most suitable zinc doses, applied by foliar spraying to increase the nutrient content of common bean and wheat plants. Based on the results obtained, it was concluded that (i) the periodic application of zinc foliar application starting at floral anthesis is capable of increasing the micronutrient content in common bean and wheat grains; (ii) the most viable source for the enrichment of bean grains is zinc sulphate; (iii) and all the doses tested (125, 250, 375 and 500 g Zn ha-1) applied via foliar in the form of zinc sulfate were effective for the enrichment of common bean and wheat grains, in relation to the control (0g Zn ha-1).

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