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An empirical study on measuring the degree of life in citiesde Rijke, Chris January 2020 (has links)
Our direct environment affects our lives directly. Christopher Alexander saw that we are able to feel or see if an object or structure is natural through the characteristics of them. He also saw that we generally feel better near these living, natural structures as it more closely resembles ourselves. Our bodies and our surroundings are made up of far more smaller than large things. When structures follow this pattern they are considered to be more natural, and when they move away from this pattern they are considered to be less natural and thus often boring or ugly. This scaling law is used to analyse the complex networks within cities. By analysing underlying structures instead of direct geometry it becomes possible to identify how living they are.This study applies these theories to analyse urban morphology within different cities. By identifying living structure within cities comparisons can be made between different types of cities. Specifically artificial and historical cities are analysed as they are counterparts in livingness. Following the identification of the living structure within these different types of cities an assessment can be made on what kind of an effect this has on our wellbeing based on Alexander’s theory. To see how living structure evolves over time a second analysis is performed which compares a city with its own evolution through time.Firstly natural cities and natural streets are identified in a bottom up approach based on the underlying structures of OpenStreetMap road data. Thereafter historical cities are compared with artificial cities because historical cities generally have living structure while artificial cities lack this. Then the developments of a historic city are identified and compared temporally. This research finds that current usage of concrete, steel and glass combined with very fast development speeds is detrimental to living structure within cities currently. Newer city developments should be performed in symbiosis with older city structures and the structure of the development should inhibit scaling as well as the buildings themselves. It is not sufficient to look only at geometry when managing cities, the importance of the fractal geometry, which is initially invisible must not be underestimated.
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Green Investments Under Uncertainty : - A cross-quantilogram approachBoyer de la Giroday, Elsa, Stenvall, David January 2019 (has links)
In this study, we analyze the quantile dependence for green bond returns and renewable energy stock returns with three major asset classes: corporate bonds, stocks and oil. Furthermore, we control the dependence structure for technology, uncertainties as well as lag structures and time-varying effects. We apply the cross-quantilogram developed by Han et al. (2016) that allows us to study the dependence structures between two time series in arbitrary quantiles. The results led us to three key findings: 1) The returns of thegreen bond market are tail-dependent on the returns of both long and short-term maturities for the corporate bond market but are not dependent on the stock market nor the oil market. The tail-dependence indicates that while investors may hold green bonds due to moral incentives, it is not enough during times of turbulence. Further, the dependence structures are short-lived. 2)The renewable energy market is dependent on oil returns of similar quantiles, suggesting that renewable energy substitutes oil when oil prices increase. However, renewable energy does not influence the oil market, indicating that oil is not a substitutional energy source for renewable energy driven firms. Renewable energy stocks are further highly dependent on the returns of the general stock market but are not influenced by the returns on the corporate bond market. 3) The dependence of both renewable energy and green bonds with the asset markets are time-varying. Our overall results obtained by this paper provides information that could help facilitate new investment allocations towards green investments. Further, the results may have immediate and important implications for investors. For those in the corporate bond market, adding green bonds does not add diversification benefits during turbulence. Similarly, renewable energy stock does not add diversification benefits to investors in the oil or stock market.
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Propriedades mecânicas do osso esponjoso e cortical do rato, após período de imobilização por aparelho gessado ou suspensão pela cauda / Mechanical properties of the rat cancellous and cortical bone, after a period of immobilization either by plaster cast or tail suspensionGuagneli, Rogério Silva 07 April 2006 (has links)
Esta pesquisa analisa o efeito de dois sistemas de restrição de atividade física - imobilização gessada e suspensão pela cauda sobre o osso longo e a vértebra, e compara esses dois modelos com a utilização de algumas propriedades mecânicas que refletem a resistência óssea. Foram utilizadas 36 ratas que, aos 90 dias de idade, foram divididas em três grupos: 10 constituíram o controle (sem tratamento), nove tiveram todo o membro inferior direito imobilizado por três semanas e 12 animais ficaram suspensos pela cauda por três semanas. Cinco animais foram descartados. Ao fim do tempo de observação foram retirados o fêmur e a tíbia do membro posterior direito e a última vértebra lombar. A tíbia foi submetida a ensaio mecânico em três pontos até a fratura. Do fêmur foram retirados corpos de prova retangulares da face anterior do terço médio da diáfise que também foram submetidos a ensaios de flexão em três pontos. Da última vértebra lombar foi obtida uma secção transversal da região média do seu corpo e ensaiada em compressão. Os parâmetros analizados foram carga máxima e tenacidade. Os resultados mostraram que ambos os métodos causaram enfraquecimento do osso longo, embora não tenha sido possível uma comparação precisa entre eles. Entretanto, para o corpo vertebral, a imobilização gessada causou enfraquecimento do osso, enquanto que a suspensão pela cauda causou seu fortalecimento, provavelmente em decorrência de maiores esforços mecânicos aplicados na região ao se manter o animal suspenso. / The effect of two systems of physical restriction - cast immobilization and tail suspension were studied on the rat long bones and vertebra through mechanical tests. Thirty-six 90 days old female rats were used and divided into three groups: ten were allocated to control and did not receive any treatment. Nine rats had the right posterior limb immobilized in a plaster cast and 12 animals were suspended by the tail. The observation period was three weeks for all the animals. After being killed, the right femur, right tibia and the last lombar vertebra were harvested. Three point mechanical compression tests were performed for the entire tibia whereas for the femur samples from the mid-diaphysis were collected and tested in flexion. The vertebrae were tested in compression at the cancellous bone region. The overall results showed that both methods caused a weakening of the long bones although it was not possible to establish a close comparison between them. For the vertebrae, the cast caused their weakening and, conversely, the tail suspension strengthened the cancellous bone. This result was seen as a biological response to an increased mechanical demand that possibly occur in the lombar region in the suspended position.
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Human rhinoviruses : development of new reverse genetics methods dedicated to the improvement of the conservation of viral heterogeneity / Les rhinovirus humains : développement de nouvelles méthodes de génétique inversée dédiées à l'amélioration de la conservation de l'hétérogénéité viraleEl Ayoubi, Miriam Diala 17 September 2018 (has links)
Les systèmes de génétique inverse permettent de manipuler les génomes viraux et se sont révélés essentiels pour étudier les virus à ARN. Récemment, une méthode basée sur la PCR, la méthode ISA (Infectious Subgenomic Amplicons), a été développée. La première partie de cette thèse se concentre sur la simplification de la méthode ISA. La principale contrainte d'ISA est l'exigence de produire des fragments génomiques modifiés qui nécessite un promoteur de transcription à l’extrémité 5’ du premier fragment et un ribozyme du virus de l'hépatite delta, suivi du signal de polyadénylation du virus simien 40 (HDR / SV40pA) à l’extrémité 3’ du dernier fragment. Ici, nous proposons une nouvelle méthode simplifiée "Haiku", dans laquelle sont fournis ces deux séquences en tant qu'amplicons séparés. Cette technique améliorée a été appliquée avec succès à une large gamme de virus dans des cellules de moustiques et de mammifères. La deuxième partie de cette thèse est axée sur la caractérisation de la population virale issue de divers systèmes de génétique inverse en utilisant le HRV-B14 comme modèle.Nos résultats montrent que le choix de la méthode a influencé la diversité génétique des populations virales mais quelle que soit la méthode utilisée, la fitness réplicative était similaire. En outre, nos données ont révélé que le poly(A)25 est la longueur optimale pour récupérer le HRV-B14 avec une efficacité élevée. La dernière partie du présent travail a examiné le potentiel de la méthode «ISA» pour conserver le spectre mutant présent dans l'échantillon viral d'origine. Nous avons montré que cette méthode récapitule au moins partiellement les quasi-espèces de la population virale native. / Reverse genetics systems allow manipulating viral genomes and have proved to be essential for studying RNA viruses. Recently, a PCR-based method, named ISA (Infectious Subgenomic Amplicons), was developed to facilitate the study of single-stranded positive-sense RNA viruses. The first part of the present work focused on simplifying the ISA method. The main constraint of the canonic protocol of the ISA method is the requirement to produce modified genomic fragments encompassing the transcription promoter and the terminator. Here, we propose the ultimately simplified "Haiku" design in which the promoter and the terminator are provided as additional separate DNA amplicons. This improved procedure was successfully applied to the rescue of a wide range of viruses in mosquito and mammalian cells. The second part of this work assessed the viral population issued from different reverse genetics systems. Using HRV B-14 as a model, we compared the genetic diversity and the replicative fitness of viruses generated using the most commonly used reverse genetics methods. Our results showed that the choice of the method influenced the genetic diversity of viral populations but whatever the method used, the replicative fitness was similar. In addition, Our data revealed that poly(A)25 is the optimal length to recover HRV-B14 with high efficiency and could be used to recover polyadenylated RNA viruses other than HRV-B14. The last part of the present work investigated the potential of the “ISA” method to conserve the mutant spectrum present in the original viral sample. We have showed that this method recapitulate at least partially the quasispecies of the native viral population.
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Atratores para equações da onda amortecida em domínios arbitrários / Attractors for damped wave equations on an arbitrary domainNogueira, Ariadne 26 March 2013 (has links)
Nesse trabalho apresentamos o estudo do artigo [25] que analisa a existência de atratores globais para uma classe de equações da onda amortecida da forma \'épsilon u IND. tt\' + \'alpha\' (x) u IND. t\' + \'BETA\' (x)u - \'\\SIGMA SOBRE i, j\' \'\\PARTIAL ind. I\' (\'a IND. i j\' (x) \'PARTIAL IND. j u\') = f(x, u) , x PERTENCE A ÔMEGA\'\', t \'PERTENCE A\' [0,\'infinito\'), u (x, t) = 0, x \'PERTENCE A\' \'\\PARTIAL ÔMEGA\', t \'PERTENCE A\' [0, \'infinito\') definidas em um domínio arbitrário \'ÔMEGA\' / In this work we describe the results of the paper [25]. In [25] the authors prove existence of global attractors for the following semilinear damped wave equation \'\\épsilon u IND. t\'t + \'alpha\'(x)u IND. t\' + \'beta\' (x)u - \'\\SIGMA SOBRE i, j \'\\PARTIAL IND. i\' (\'a IND. i j\' (x) \'\\PARTIAL IND. j u\') = f (x, u), x \'IT BELONGS\' \'ÔMEGA\', t \'IT BELONGS\' [0, \'INFINITY\'), u(x,t), x \'IT BELONGS\' \'\\PARTIAL ÔMEGA\', t \'IT BELONGS\' [), \'INFINITY\'0 on an arbitrary domain \'OMEGA\'
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Male sexually selected traits of the barn swallow Hirundo rustica gutturalis in ChinaLi, Nana January 2017 (has links)
The barn swallow (Hirundo rustica) is represented by six subspecies and has two well-studied ornamental traits, tail length and ventral plumage colour, which vary geographically among subspecies. Sexual selection on these traits has been suggested to drive speciation. The European subspecies rustica has pale ventral feathers and long tail streamers, and females prefer males with longer tail streamers. The North American erythrogaster has shorter tails and red ventral plumage and their females use redness of ventral plumage as a mate choice cue. In the Middle East, the subspecies transitiva bears long tail streamers and red ventral feathers, both of which have been suggested to show male attractiveness. The Asian subspecies gutturalis has a pale belly with short but dimorphic tails. Studies in Japanese populations have suggested that the white spot on the tail feathers and throat patch are sexually selected in males, but this explanation leaves the dimorphism of tail streamers unexplained. To further investigate the sexually selected traits of gutturalis, especially the role tail streamers might play, I studied a population of the barn swallow gutturalis in China between 2013 and 2015, and conducted a partial cross-fostering experiment in 2015. My data indicate that male tail streamers are sexually selected in the gutturalis population in China. Longer-tailed males (with deeper fork tails) were cuckolded less frequently and had a higher reproductive success, they also had mates that invested more in parental care and had a higher total peak body mass of offspring. Both male and female body condition (body mass and tarsus length) influenced offspring growth. Males with larger body mass initiated breeding earlier and their offspring had a larger body mass on day seven after hatching and grew faster as determined by a cross-fostering experiment. Larger females reared offspring that grew faster and reached a higher peak body mass both in original nests and nests with cross-fostered nestlings. Based on feeding rate observations and the cross-fostering experiment, it seems that females obtain indirect benefits rather than direct benefits from mating with more attractive males.
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Desempenho de leitões submetidos a diferentes densidades durante a fase de creche / Performance of pigs submitted to differents stocking densities during the nursery phaseMarimon, Bruno Teixeira January 2018 (has links)
O objetivo deste estudo foi avaliar o efeito da densidade sobre o desempenho e o comportamento de leitões na fase de creche. Um total de 560 leitões desmamados (peso médio de 5,75 ± 0,9 kg e idade média de 20,92 ± 0,8 dias) foram aleatoriamente alojados em quatro tratamentos com diferentes densidades: T0,33, T0,28, T0,23 e T0,18 (0,33, 0,28, 0,23 e 0,18 m²/animal respectivamente). As baias continham 20 animais e a ração foi fornecida à vontade. As lesões de cauda e orelha foram graduadas em escores de 0 a 4 e o número de lesões de briga foram avaliados semanalmente. Dezesseis baias foram filmadas em três momentos (1ª, 4ª e 6ª semana de alojamento) para avaliação da frequência de brigas e de belly nosing. Foi observado um efeito linear da densidade sobre o ganho de peso diário (GPD; P=0,049), um efeito quadrático sobre o peso aos 42 dias (P=0,030) e uma tendência de efeito quadrático para o consumo médio diário (CMD; P=0,075). Não houve efeito da densidade na conversão alimentar (CA) e no coeficiente de variação (CV) do peso aos 42 dias. Foi observado um maior número de leitões apresentando lesões severas de orelha no grupo T0,18 quando comparado ao T0,33 (P = 0,019) e T0,28 (P = 0,056). Um maior número de animais com lesões moderadas ou severas foi observado no grupo T0,18 (P < 0,05) do que nos demais grupos para lesões de orelha, e do que T0,33 para lesões de cauda. Houve um efeito linear da densidade sobre a frequência de brigas, com uma maior ocorrência nos grupos com menos espaço. Contudo, não foi observado efeito sobre o número de lesões de briga ou de casos de belly nosing. Em conclusão, o aumento da densidade afetou negativamente o desempenho dos leitões, além de aumentar a ocorrência de comportamentos indesejáveis. / The aim of this study was to evaluate the effect of space allowance on performance and behavior of nursery pigs. At weaning 560 pigs (5.75 ± 0.9 kg of body weight and 20.92 ± 0.8 days of age) were randomly assigned in four treatments with different stocking densities: T0.33, T0.28, T0.23 and T0.18 (0.33, 0.28, 0.23 and 0.18 m²/pig respectively). Pens were standardized to have the same group size (20 pigs/pen) and feed was provided ad libitum. Tail and ear biting lesions and the fighting lesions were weekly observed. Sixteen pens were videotaped in three different moments (1st, 4th and 6th housing week) and the frequency of fights and belly nosing were recorded. A linear effect was observed of stocking density on average daily gain (ADG; P=0.049), a quadratic effect and a quadratic tendency of effect were observed on body weight at 42 days after weaning and on average daily feed intake (ADFI) (P=0.030; P=0.075, respectively). There was no effect of stocking density on the gain:feed ratio or weight coefficient of variation (CV) at day 42. Higher graduation of severe ear lesions was observed in pigs from T0.18 when compared to T0.33 (P = 0.0196) and T0.28 (P = 0.056). A higher number of pigs with moderate or severe tail and ear lesions was observed in T0.18 (P > 0.05). Moreover, it was observed a linear effect of density on the frequency of fights, with higher occurrence in groups housed in restricted spaces. However, no effect of stocking density was observed on fight lesions or belly nosing among treatments. In conclusion, increased density negatively affected the performance of piglets and increased the occurrence of unsuitable behaviors.
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Efeitos comportamentais, neuroquímicos e imunes do estresse de contenção em camundongos de alta e baixa imobilidade selecionados pelo teste de suspensão da cauda / Behavioral, neurochemical and immune effects of restraint stress in mice of high and low immobility selected by the tail suspension testSilva, Thiago Moirinho Reis e 09 February 2018 (has links)
O estresse destaca-se como um importante fator de risco para o desenvolvimento de diferentes doenças. Reconhecido atualmente como uma epidemia global pela Organização Mundial da Saúde e afetando mais de 90% da população mundial, o estresse apresenta grande associação, em particular, com os transtornos mentais. Dentre esses, a depressão se sobressai afetando sozinha cerca de 350 milhões de pessoas em todo mundo. Poucas experiências talvez sejam tão comuns entre os organismos quanto a exposição a eventos estressantes Alguns tipos de estresses emocionais, como a tristeza, e outros no qual o organismo é afetado por períodos prolongados, tem demonstrado serem capazes de promover disfunções imunes e distúrbios comportamentais que podem ser compreendidos através do campo interdisciplinar de estudo da neuroimunomodulação, uma vez que podem desencadear respostas específicas no eixo hipotálamo-hipófise-adrenal, que, por conseguinte, podem modular diferentes efeitos fisiológicos decorrentes da exposição ao estresse. Dentre esses efeitos, é possível destacar a capacidade de resiliência e / ou resistência ao estresse, que podem conferir uma capacidade diferenciada de recuperação, como também aumento na susceptibilidade a doenças. Considerando os aspectos distintos do estresse e os diferentes estados patológicos a ele associados, esse trabalho teve como objetivo avaliar os efeitos comportamentais, neuroquímicos e imunes do estresse de contenção de duas horas em camundongos, selecionados para um perfil distinto de reatividade ao estresse inescapável pelo teste de suspensão da cauda. Para isso, camundongos machos de alta e baixa imobilidade foram previamente selecionados e submetidos diferentes testes pré e pós exposição ao estresse de contenção de duas horas: (i) análise dos comportamentos tipo-depressivos e ansiosos, (ii) análise dos neurotransmissores no córtex pré-frontal, hipotálamo e mesencéfalo e, (iii) análise de citocinas pró- inflamatórias no córtex pré-frontal e hipotálamo. Nossos resultados mostraram que animais de alta e baixa imobilidade apresentam comportamentos diferentes antes e após a exposição ao estresse, além de apresentar um comportamento de grooming distinto após o estresse de contenção. A exposição ao estresse também promoveu alterações entre as concentrações serotoninérgicas, dopaminérgicas e noradrenérgicas entre animais de alta e baixa imobilidade, tanto no córtex pré-frontal, hipotálamo e mesencéfalo. Além disso, o perfil imune também se revelou alterado entre esses animais, principalmente em TNF- no hipotálamo, revelando uma ativação dos sistemas relacionados ao estresse. Considerando o conjunto dos dados apresentados, nossos resultados sugerem uma ativação diferenciada do eixo hipotálamo-hipófise-adrenal entre camundongos de alta e baixa imobilidade e, ainda, que os animais de baixa imobilidade apresentam um perfil de resiliência ao estresse contenção, tendo animais de alta imobilidade o perfil oposto / Stress stands out as an important risk factor for the development of different diseases. Currently recognized as a global epidemic by the World Health Organization and affecting more than 90% of the world population, stress can be strongly associated with mental disorders. Among these, depression can be highlight affecting alone about 350 million people worldwide. Few types of emotional stresses, such as sadness, and others which the organism is affected for long periods, have demonstrated to be capable of promoting immune dysfunctions and behavioral disorders. These changes can be understood through the interdisciplinary field of study of the neuroimmunomodulation, since it can trigger specific responses in the hypothalamic-pituitary-adrenal axis, which, therefore, could modulate different physiological effects resulting from the exposure to stress. Among these effects, it is possible to highlight the capacity of resilience and / or resistance to stress, which can confer a differentiated capacity of recovery, as well as increase in the susceptibility to diseases. Considering the distinct aspects of stress and the different pathological conditions associated, this study aimed to evaluate the behavioral, neurochemical and immune effects of two-hour of restraint stress in mice selected for a different profile of stress reactivity to the inescapable stress of the tail suspension test. For this, male mice of high and low immobility were previously selected and submitted to different tests before and after exposure to a two-hour restraint stress protocol for the analysis of: (i) the depressive and anxiety-like behaviors; (ii) concentrations of neurotransmitters in the prefrontal cortex, hypothalamus and midbrain; (iii) expression of proinflammatory cytokines in the prefrontal cortex and hypothalamus. Our results showed that animals of high and low immobility presented different behavioral profiles before and after exposure to stress and presented a distinct grooming behavior after the restraint stress. Exposure to stress also promoted changes between the serotonergic, dopaminergic and noradrenergic concentrations between animals of high and low immobility in the prefrontal cortex, hypothalamus and midbrain. In addition, the immune profile revealed to be altered among these animals, especially in TNF- in the hypothalamus, showing an activation of stress-related systems. Considering the set of data presented, our results suggest a differentiated activation of the hypothalamic-pituitary-adrenal axis between mice of high and low immobility and, also, that the animals of low immobility present a resilience profile to the restraint stress, having high immobility animals the opposite profile
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Influência das lesões de caudofagia na fase de terminação sobre o desempenho zootécnico, sanitário e condenações ao abate de suínos / Influence of tail biting on pig performance, health, lesions and condemnations at slaughter of finishing pigsMarques, Brenda Maria Ferreira Passos Prado January 2010 (has links)
O presente trabalho avaliou a influência de lesões de caudofagia em suínos na terminação sobre o ganho de peso, variáveis sanitárias, ocorrência de lesões e condenações ao abate. O estudo foi realizado em quatro propriedades (PROP) de terminação de suínos. Para cada suíno com lesão de caudofagia foram selecionados dois controles, totalizando a avaliação dos seguintes números de animais: PROP1: 87; PROP2: 33; PROP3: 60; PROP4: 132. As lesões na cauda foram classificadas conforme o grau de severidade (escore de 0 a 4, sendo 0 normal e a severidade aumentando até os graus 2 e 3, e como grau 4 para lesões cicatrizadas). A cada uma de 4 a 6 avaliações (conforme a idade inicial do 1o diagnóstico do problema), os animais eram pesados e as lesões na cauda avaliadas. Em todas as propriedades, foi observada uma recuperação das lesões de caudofagia na terceira avaliação. Nas PROP 1 e 3, animais com lesões de escore 3 (severas) tiveram menor ganho de peso (P<0,05) comparados aos animais de escore 0. Além disso, na PROP3, animais com escore 3 foram menos pesados (P<0,05) ao abate do que aqueles de escore 0. A chance de animais com escore 3 terem artrite e apresentarem nódulos subcutâneos e/ou abscessos foi 25,5 e 30,4 vezes maior, respectivamente, em comparação aos animais com escore 0. Tanto animais com escore 2 (moderado) quanto os com escore 3 apresentaram maiores chances (P<0,05) de terem abscessos ou lesões pulmonares (pleurite e pneumonia embólica) em comparação aos animais sem lesão de cauda. Houve desvio ao Departamento de Inspeção Federal (DIF) de 21,6% (62/287) das carcaças, de animais com lesões e controles, sendo que a caudofagia foi a causa de 66,1% das condenações. Animais com lesões de escore 2 e 3 apresentaram 6,0 e 9,3 vezes maiores chances de terem suas carcaças desviadas ao DIF, respectivamente, comparados aos animais de escore 0. Os animais com lesões de caudofagia representaram 63,0% das carcaças que tiveram destino “não exportável” e 75,0% das carcaças com outros destinos. Considerando os percentuais aproximados de perdas relativas definidas pelo frigorífico visitado para as categorias de condenação (não-exportável, embutido, conserva e graxaria), isto representaria a perda de 15,58 animais (total de 18,12% entre os 86 animais que foram diagnosticados com caudofagia na granja). Isso permite concluir que, nas condições desse estudo, de cada 5 animais que são visualizados com canibalismo na terminação vai ocorrer a perda total de 1 no frigorífico. A esse prejuízo devem ser somados os animais que foram sacrificados nas granjas ou que vieram a morrer devido aos problemas causados pelas complicações das lesões na cauda. No estudo atual, foi possível determinar que, entre todos os que haviam apresentado lesões de canibalismo nas granjas, apenas dois mantinham lesões detectáveis externamente por ocasião do abate, o que pode ser explicado pela ocorrência muito precoce das lesões de caudofagia nos casos observados. Por outro lado, no abate desses animais do grupo com caudofagia, mas sem lesões externas no abate, foi observado um grande número de condenações por abscessos e lesões pulmonares. Isso sugere existir uma dicotomia entre as situações de campo e de frigorífico, reforçando a necessidade de uma melhor ligação entre esses contextos para estimar adequadamente o seu impacto. / The present work assessed the influence of tail biting lesions in finishing pigs in relation to weight gain, health, occurrence of lesions and carcass condemnation at slaughter. The study was carried out in four finishing units (PROP) and the following number of animals were assessed: PROP1: 87; PROP2: 33; PROP3: 60; PROP4: 132. To each animal with tail biting two controls were selected. Tail lesions were classified according the degrees of severity (scores from 0 to 4, 0 classified as normal and severity increasing until the degrees 2 and 3, and degree 4 meaning healed lesions). In each one of 4 to 6 visits (depending on the age of the 1st diagnosis of the problem), the animals were weighed and tail lesions assessed. In all farms, healing of tail lesions was observed in the third evaluation. In PROP 1 and 3, injured animals with score 3 showed smaller weight gain (P<0,05) when compared with animals with score 0. In PROP3, animals with score 3 were lighter (P<0,05) at slaughter than those with score 0. The chance for animals with score 3 to show arthritis and subcutaneous nodules and/or abscesses was 25,5 and 30,4 times higher, respectively, when compared with animals with score 0. Animals with scores 2 (moderate) and 3 (severe) had higher chances (P<0,05) of having abscesses or lung lesions (pleuritis and embolic pneumonia) when compared to animals without tail lesions. Trimming was observed in 21,6% (62/287) of the carcasses of injured and controls, and tail lesions corresponded to 66,1% among condemnations. Animals with lesions of scores 2 and 3 presented 6,0 and 9,3 higher chances of having trimmed carcasses, respectively, when compared with animals with score 0. Animals with tail lesion represented 63,0% of the carcasses with “non exportable” destination and 75,0% of the carcasses with other destinations. Considering the percentile of losses in each category defined by the slaughterhouse visited in this work (non exportable, processed, preserve and grease), this would represent a total loss of 15,58 animals (loss of a total of 18,82% among 86 animals with cannibalism). In the conditions of this study, this would mean that from 5 animals diagnosed with cannibalism in the finishing period, one would be totally wasted at the slaughter time. To this damage must be added the animals that were euthanazied in the herds or those died due to complications of tail injuries. In the present study, an individual diagnosis was performed in the farms of all animals with external lesions suggestive of tail cannibalism and all affected animals were followed at slaughter. Because of this, it was possible to observe that between all animals diagnosed with cannibalism at farm level, only two remained with lesions externally detectable at slaughter, what could be explained by the precocity of the lesions present in the cases analyzed by us. On the other hand, at the slaughter of this group of animals of the cannibalism group but without external lesions at slaughter, a great number of condemnations occurred by abscesses and lung lesions. This suggests that there is a dicotomy between slaughter and field situations, reinforcing the need for a better liaison between these contexts, to be able to adequately assess its impact.
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Estratégias de diversificação de carteiras de ações com dependência assimétrica / Strategies to diversify portfolios with asymmetric dependenceBergmann, Daniel Reed 04 March 2013 (has links)
DeMiguel, Garlappi e Uppal (2009) fizeram a comparação da regra 1/N ou de Talmud com 14 modelos de otimização que vieram depois do trabalho de Markowitz (1952). As conclusões mostraram que todos os modelos de alocação ótima analisados tiveram um desempenho inferior ao da regra de Talmud. Tu e Zhou (2011) propuseram uma combinação entre Markowitz e Talmud para que tal modelo superasse Talmud. Os resultados obtidos foram satisfatórios. A desconsideração dos eventos extremos (dependência assimétrica ou caudal) durante o processo de construção de carteiras poderá diminuir as habilidades dos gestores de ativos em reduzir o risco através da diversificação. A modelagem de cópulas sobre os retornos dos ativos nos permite calcular uma alternativa para medir a dependência dos ativos em eventos extremos através do índice de dependência caudal inferior. Hatherley e Alcock (2007) relataram que o modelo de Markowitz tende a subestimar as perdas potenciais que venham a ocorrer na presença de eventos extremos de mercado (crashes) para um determinado nível de retorno esperado. Verificamos se as estratégias com dependência caudal superaram Talmud, o modelo de Markowitz e o modelo de Tu e Zhou (2011) através da simulação de 1.000 carteiras com 3, 5, 10 e 20 ativos escolhidos ao acaso do índice DJIA no período de 03/1990 até 12/2012. Concluímos que os modelos de dependência caudal e o de Markowitz tiveram uma desempenho fora da amostra superior ao Talmud e ao modelo de Tu e Zhou (2011) para as carteiras com 3, 5, 10 e 20 ativos. A estratégia com dependência caudal superou Markowitz, em termos de retorno acumulado, em mais de 60% dos meses considerados em todas as análises. Os resultados apontam que a regra de Talmud deve ser descartada num contexto de construção de carteiras com ações frente à estratégia com dependência caudal. / DeMiguel, Garlappi and Uppal (2009) made a comparison of rule 1 / N or Talmud with most optimization techniques that followed the work of Markowitz (1952). The conclusions were devastating for all asset allocation models in the context of portfolios combined with other portfolios. Tu and Zhou (2011) proposed a combination between Markowitz and Talmud to overcome such a rule Talmud. The results were satisfactory. In the presence of extreme events, the Pearson correlation coefficient tends to increase in magnitude, making spurious results diversification based solely on this factor. The elimination of extreme events (asymmetric or tail dependence) during the portfolio construction process can reduce the skills of asset managers to reduce risk through diversification. The copula theory allows us to calculate an alternative to measure the dependence of extreme events in assets through the index lower tail dependence. Hatherley and Alcock (2007) reported that the Markowitz model tends to underestimate the potential losses that may occur in the presence of extreme market events (crashes) for a given level of expected return. We check that the strategies with tail dependence overcame Talmud rule, the Markowitz model and the model of Tu and Zhou (2011) by simulating 1,000 portfolios with 3, 5, 10 and 20 randomly selected assets from DJIA for the period 03/1990 until 12/2012. We conclude that models of tail dependence and Markowitz had more performance ex-ante than Talmud and the Tu and Zhou (2011) model for portfolios with 3, 5, 10 and 20 assets. Tail dependence models overcome Markowitz, in terms of cumulative return, in over 60% of months considered in the analysis. The results indicate that the Talmud rule should be discarded in a context of constructing portfolios with individual stocks ahead strategies with tail dependence.
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