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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.
71

Characterisation of telomere length dynamics in dairy cattle and association with productive lifespan

Seeker, Luise Avelina January 2018 (has links)
Telomeres form protective caps at the ends of linear chromosomes. They consist of repetitive DNA nucleotides and associated proteins of the shelterin complex. In vitro telomeres become shorter during cell division and when a critical shortness is reached they trigger a DNA damage response that leads to replicative senescence or apoptosis. Telomere shortening is a recognised hallmark of cellular ageing and seems to be also associated with organismal ageing. Telomere length (TL) and the rate of shortening vary across individuals and several studies have found that short telomeres and fast telomere depletion are associated with poor survival and early onset of age related diseases. However, longitudinal studies are needed to better understand the relationship of TL and TL dynamics with longevity measures. Relevant studies on livestock species are largely missing from the literature. In the dairy industry, farmers are forced to cull a considerable percentage of their heifers and cows at a young age due to fertility problems or diseases. As a consequence many replacement heifers have to be reared to maintain a specific herd size. This results in increased costs, consumption of resources, and damage to the environment. Breeding for an improved productive lifespan is difficult because longevity measures are recorded at the end of life and are known to have a low heritability. Therefore, the expected genetic improvement is generally slow, but could be considerably accelerated if an early life heritable biomarker was identified that is predictive of productive lifespan and could be used for animal selection. The question is if TL could be used as such a biomarker. The objectives of this thesis were to 1) develop robust methods to measure average relative leukocyte TL (RLTL) in cattle, 2) examine RLTL dynamics with age at a population as well as at an individual level, 3) estimate genetic parameters and 4) assess the association of RLTL and RLTL dynamics with productive lifespan. A quantitative polymerase chain reaction (qPCR) based assay developed for human studies was adapted to cattle and delivered robust results (repeatability > 80%, coefficient of variation=0.05). Different DNA extraction methods were tested for their effect on RLTL measurements and it was demonstrated that fast silica based DNA extraction methods are suitable for telomere projects which can improve the sample throughput and enable large-scale projects. Subsequently, RLTL in 1328 whole blood samples of 308 Holstein Friesian dairy cows and additionally in 284 whole blood samples of 38 female calves was measured. Repeatability and random regression models were used for the statistical analysis of telomere data. RLTL decreased considerably within the first year of life, but remained relatively stable afterwards at population level. Animals varied significantly in their amount and direction of telomere change. The genetic correlation between consecutive measurements in the same individual weakened with increasing sample interval from r=1 to r=0.69 which indicates that TL in the beginning of life might be under a different genetic control than TL later in life. For the first time in a livestock species we calculated heritability estimates for RLTL which were high (0.32-0.38) and remained constant over life. Long telomeres at birth were not predictive of better productive lifespan. However, animals with long RLTL at the ages of one and five years had a survival advantage. Also, animals that showed less average RLTL attrition over their lives remained in production for longer. TL dynamics differed among individuals and a considerable subset of individuals demonstrated telomere lengthening between consecutive measurements. On average, telomeres tend to shorten early in life and then remain relatively constant. While TL is a heritable trait throughout lifetime, telomere change is not heritable. Short TL at specific ages and telomere attrition over life were associated with poorer productive lifespan.
72

Power management in Wireless Sensor Networks (WSNs)

Kamsuvan, Thanisara January 2016 (has links)
The wireless sensor network (WSN) is increasingly used in many areas nowadays. It can be applied to provide the solutions to environmental problems, help increasing security and safety systems, and make the detection of the problems more efficient, e.g. the earthquake or tidal wave, which will harmful to humans. The WNS is durable and resistant to all types of terrain and climate, but while the WSN system is more and more widespread, one of the obstacles hindering the growth of this technology and the demand for WSN applications is the limited battery lifespan. Consequently, there is a significant requirement for techniques for prolonging the battery’s lifespan. Therefore, one potential solution is to use alternative energy sources combined with the sensor nodes in WSN, specifically energy harvesting from existing environmental sources. This research project reviews the characteristics of each kind of energy harvesting, understanding the various energy sources (solar energy, vibration energy and wind power), including wireless power transfer (WPT) by using electromagnetic (EM) radiation energy transfer or RF radio-frequency emission and magnetic coupled energy transfer. They are adopted for extending node’s life in the WSN, based on published information. Then it compares these diverse alternative energy methods and identifies for the most suitable energy harvesting method for application to wireless sensor nodes in order to prolong the lifespan of the battery. The major findings from the researcher include that wireless power transfer energy harvesting (WPT) using the magnetic field is the most appropriate tool for extending the lifespan of the WSN system. In addition, the author also designed an experiment to test this alternative energy, achieving by modelling the wireless power transfer with four coils. From the experimental results, it can be seen that the WPT technique using energy harvesting with magnetic inductive source can be applied to prolong the lifespan of the WSN system.
73

Augmentation de la durée de vie des panneaux photovoltaïques par surveillance et contrôle / Increase of photovoltaic panels lifespan by monitoring and control

Nehme, Bechara Fadi 27 May 2016 (has links)
Les rendements de conversion des cellules solaires atteignent en moyenne aujourd’hui 15%. Malgré ces rendements acceptables, il reste un verrou technologique important à lever : l’amélioration de la durée de vie des modules photovoltaïques. On observe en effet au cours de l’utilisation de ces composants dans des conditions climatiques intermittentes : pluie, neige, moisissures, poussières rayons UV, chocs, corrosion etc.... une perte rapide des propriétés optoélectroniques en fonction des conditions d’utilisation. L’objectif de cette thèse est d’essayer d’améliorer la durée de vie des panneaux solaires et d’améliorer la fiabilité des modules en diminuant le taux de dégradation.Notre approche commence par prendre en compte les effets de vieillissement et des défauts des modules photovoltaïques dont la dégradation est liée à la température, humidité, à la lumière Ultra violette, les fissures etc…. Les défauts de fonctionnement sont analysés et étudiés pour comprendre l’effet et l’importance de chaque paramètre dans les différents modes de dégradation afin de développer des modèles de simulation qui tiennent compte des conditions environnementales.Des algorithmes de commande ont été développés pour une utilisation qui évite au mieux les défauts et permet aux modules photovoltaïques de fonctionner dans des conditions optimales pour l’atténuation des dégradations. / Conversion efficiency of solar cells is now on average reaching 15%. Despite these acceptable yields, it remains important to raise a technological limitation: the improvement of the life span of photovoltaic modules. Effects are observed during the use of these components in intermittent weather: rain, snow, molds, dust UV rays, shock, corrosion etc... rapid losses of optoelectronic properties depending on the usage conditions. The objective of this thesis is in twofold: -to try to improve the lifespan of solar panels, and -to improve the reliability of the photovoltaic modules by decreasing their degradation rate. Our approach begins by taking into account the effects of aging of photovoltaic modules whose degradation is related to temperature, moisture, Ultra violet light, cracks etc... Faults are analyzed and studied to understand the impact and the importance of each parameter in the different modes of degradation to develop simulation models that take into account external environmental conditions. Control algorithms have been developed for a best utilization avoiding defects and allowing photovoltaic modules to operate in optimal conditions for mitigation of degradation processes.
74

Understanding mosquito vectors and methods for their control

Lambert, Ben January 2017 (has links)
Mosquitoes spread diseases that shorten and worsen the lives of many people, chiefly children in poor countries, around the world. Since Ronald Ross' discovery at the end of the nineteenth century that mosquitoes transmit malaria, field entomologists have collected a great deal of information about mosquito ecology. Despite this tremendous effort, there still remain significant gaps in our knowledge of mosquito ecology, in part, reflecting the significant variation in mosquito ecology across species and geographies. The main aim of this thesis is an attempt to synthesise the substantial information that field entomologists have collected on mosquito lifespan. In Chapters 2 and 3, I conduct meta-analyses of the two predominant approaches used to estimate mosquito lifespan: mark-release-recapture experiments and female mosquito dissection-based studies, respectively. These analyses produce estimates of mosquito lifespan by species and genus, and more broadly, allow for an appraisal of these two experimental approaches. In Chapter 4, I describe a recently developed approach, known as near-infrared spectroscopy, which enables estimation of the age of individual mosquitoes, and then perform an in silico analysis to explore the use of this technology for estimating the average lifespan of wild populations of mosquitoes. The emergence of mosquito resistance to the main insecticides used in vector control, along with the concerning recent discovery that the malaria parasites in Asia are becoming resistant to arteminisin - an important drug used to treat malaria - highlight the need for novel approaches to control disease transmission. Some recently-proposed approaches involve genetic modification of the mosquito vectors, for example, to render them incapable of acting as hosts for disease or to reduce their fecundity. In Chapter 5, I model the impact of a release of mosquitoes carrying a genetic construct known as a homing endonuclease, which has been constructed to bias the sex of mosquito offspring towards males, in computational environments that capture some facets of the real life landscapes where mosquito borne disease is rife. About a century ago, the famous Italian Malariologist Giovanni Grassi declared that malaria was a "giant with clay feet"; reflecting the optimism, in some academic circles at the time, that eradication of this terrible disease would soon occur. Unfortunately, a century of often unsuccessful attempts to control and eradicate malaria, and other mosquito borne diseases, would follow Grassi's statement, meaning that this fight is likely to continue throughout the twenty-first century. We now know much more about mosquitoes and mosquito borne disease than we did a generation ago, but there is still crucial information that we do not. In this thesis, I argue that in order to make significant inroads to disease eradication, further research on mosquito ecology is crucial. Only when we better understand our unwitting mosquito foe, can we design and implement effective disease control measures that are so desperately needed in those most desperate parts of the world.
75

ANÁLISE COMPARATIVA ENTRE OS MÉTODOS DE DIMENSIONAMENTO DE PAVIMENTOS FLEXÍVEIS DO BRASIL E O MÉTODO DA AASHTO / COMPARATIVE ANALYSIS BETWEEN THE FLOORS SCALING METHODS OF BRAZIL AND THE FLEXIBLE APPROACH AASHTO

Fernandes, Wagner Dambrós 14 July 2016 (has links)
The Brazil as a country road, which needs much its highways, however, currently the country uses for PAVEMENT scaling of a method developed in 1966 and updated in 1981 by Murilo Souza Engineer extinct DEER. The method that your main idea it is sizing foundation which is in the CBR, based on the empirical method. This way , along the growing fleet of the country and the emergence of some works of mechanistic-empirical nature, this work aims to make the analysis of a pavement through DNIT method and software use SisPavBR developed by Felipe Franco in their studies that began in 2007 in his thesis, making the adjustment and calibration of some performance prediction models .Similarly, We also did the use the AASHTOWare Pavement software developed by AASHTO as well as determining the thickness of the coating layer required to meet the demands imposed on the floor by means of mechanistic and empirical methods. For this, was then done using vehicle counting performed to BR116, however, they were necessary to create traffic volume of tracks (N) due DNIT method does not consider the arrangement of axes that SisPavBR and AASHTO are in their reviews .It was also conducted a survey of the executive cost km deck sized for each method, and statistical analysis was performed by AASHTO with variations in thickness of the coating base, subbase, base resilience modules, sub-base, subgrade and the volume of traffic to determine which of these variables cause greater interference on performance criteria. Thus, it was found that the surface scaled by DNIT need a coating thickness of 12.5 cm, the need SisPavBR 19.5 cm and 40 cm AASHTO needed, as the cost of the pavement was more higher for the dimensioning and AASHTO DNIT and SisPavBR had closest costs. The life time of DNIT pavement scaling was well below expectations in both analyzes, arriving in a case last only two months. Statistical analysis determined five equations to determine the deterioration mechanisms with R² above 0.85; it was determined that the major variables that affect the performance of flexible pavements are traffic volume and thickness of the coating. / O Brasil como um país rodoviário, necessita muito de suas rodovias, no entanto, atualmente o país faz uso para dimensionamento de pavimentos de um método desenvolvido em 1966 e atualizado em 1981, pelo Engenheiro Murilo Souza do extinto DNER. Método este que seu principal fundamento de dimensionamento está no CBR, baseando-se no método empírico. Desta forma, juntamente à crescente frota do país e com o surgimento de alguns trabalhos de cunho mecanístico-empírico, este trabalho tem como objetivos, fazer a análise de um pavimento por meio do Método do DNIT e do uso do software SisPavBR desenvolvido por Felipe Franco em seus estudos que iniciaram em 2007 em sua tese, realizando o ajuste e calibração de alguns modelos de previsão de desempenho. Da mesma forma, foi utilizado também o software AASHTOWare Pavement desenvolvido pela AASHTO, bem como a determinação da espessura da camada de revestimento necessária para atender as solicitações impostas aos pavimentos por meio dos métodos mecanísticos-empíricos. Para isto, foi então feito uso da contagem de veículos realizados para BR116, no entanto, foi necessário criar faixas de volume de tráfego (N), devido o método do DNIT não considerar o arranjo dos eixos que o SisPavBR e AASHTO fazem em suas avaliações. Foi realizado também o levantamento do custo executivo do km de pavimento dimensionado por cada método, e uma análise estatística foi realizada por meio da AASHTO com variações nas espessuras do revestimento, base, sub-base, módulos de resiliência da base, sub-base, subleito e o volume de tráfego, para determinar quais destas variáveis causam maior interferência nos critérios de desempenho. Desta maneira, verificou-se que o pavimento dimensionado pelo DNIT necessita de uma espessura de revestimento de 12,5 cm, o SisPavBR necessita de 19,5 cm e a AASHTO precisou de 40 cm, da mesma forma que o custo do pavimento foi mais elevado para o dimensionamento da AASHTO e o DNIT e SisPavBR tiveram custos mais próximos. A vida de projeto do pavimento do DNIT ficou bem abaixo do esperado em ambas as análises, chegando em um caso durar apenas 2 meses. A análise estatística determinou 5 equações para determinação dos mecanismos de deterioração com R² acima de 0,85; foi possível determinar que as principais variáveis que influenciam no desempenho dos pavimentos flexíveis são o volume de tráfego e a espessura do revestimento.
76

Využití demografických sítí v ekonomické statistice / Using Demographic Networks in Economic Statistics

Písaříková, Petra January 2017 (has links)
One of the first analytical tools that can be used to analyze data is the graphical representation. The time that is used as a measure in tasks in a wide range is problematic to grasp, and its mapping is not easy. In demographics, some tools, such as the Lexis diagram, are used. However, the list of graphical tools can be extended by diagrams that look at the time measure in different ways. Their use can be demonstrated not only on demographic data but also on non-demographic data and the modern statistical program R can be used too.
77

Drosophila melanogaster and its bacterial partners : community dynamics and effects on animal physiology / Drosophila melanogaster et ses partenaires bactériens - Dynamique des communautés et effets sur la physiologie animale

Téfit, Mélisandre 16 December 2016 (has links)
Dans la nature, les relations symbiotiques sont très répandues, et d’une importance écologique fondamentale. Les animaux sont apparus, ont évolué et vivent maintenant constamment associés avec une multitude de micro-organismes. Parmi les différents types de symbioses existantes, celles liant le microbiote et son hôte occupent une place centrale et équilibrée, basée sur des relations commensales ou mutualistes entre les partenaires. Ce microbiote est de plus en plus étudié, notamment en raison du rôle crucial qu’il joue dans la santé animale ainsi que dans le développement de pathologies. Dans cette effort de recherche, Drosophila melanogaster représente un modèle de choix, grâce à la facilité de générer et maintenir des lignées de mouches axéniques, ainsi que de les réassocier avec une communauté microbienne définie.L’association de la drosophile avec l’un des ses commensaux naturels, Lactobacillus plantarum, a permis de révéler l’effet promoteur de croissance de cette bactérie. En cas de carence nutritionnelle, des larves associées avec L. plantarum se développent beaucoup plus rapidement que leurs semblables axéniques. L’ajustement du développement en fonction des conditions environnementales est cependant crucial pour la formation d’un individu à la santé optimale, et dans ce cas les individus grandissent plus vite alors que les conditions nutritionnelles sont pauvres. Nous avons donc cherché à déterminer si ce qui semble être un avantage au stade larvaire pouvait se révéler délétère pour les stades suivants et avoir un effet néfaste sur les mouches adultes. Nous avons montré que L. plantarum est bénéfique pour D. melanogaster tout au long du cycle de vie de la mouche et permet l’émergence précoce d’adultes matures et fertiles sans impact négatif sur leur santé et leurs performances. De plus, dans certaines conditions, cette souche commensale entraîne une augmentation de la durée de vie de mâles nutritionnellement carencés.Des études plus larges analysant l’interaction de la drosophile avec plusieurs espèces bactériennes peuvent informer sur la dynamique d’un microbiote de mouche. En effet, au sein de la niche environnementale, les bactéries sont échangées entre l’animal et son substrat nutritif, et ces transferts réciproques pourraient altérer la composition de la communauté. Nous avons étudié cette question en utilisant un microbiote naturel, et avons observé un haut degré de similitude entre les bactéries associées avec les mouches et la composition de la communauté bactérienne de la nourriture, illustrant le caractère stable de l’association du microbiote de la drosophile avec la population de mouches au sien de la niche.Ces résultats illustrent le pouvoir du modèle drosophile pour l’étude des interactions entre les animaux et leur microbiote, qui permet de déchiffrer la dynamique des communautés de bactéries commensales ainsi que leur impact sur la physiologie animale. / In nature, symbiotic relationships are widespread, and of paramount ecological importance. Animals have appeared, evolved, and are now living constantly associated with a variety of microorganisms. In the spectrum of different symbioses types, the microbiota occupies a central and balanced part by establishing commensalistic or mutualistic relationships with its host. Over the last years, the microbiota has been extensively studied given the crucial role it plays in animal health and disease. In this research effort, Drosophila melanogaster represents a fruitful model, thanks to the ease to generate and maintain axenic flies, and the simplicity of re-associating them with a defined microbial community.The association of Drosophila with one of its natural commensals, Lactobacillus plantarum, revealed a growth-promoting effect mediated by this bacterial species. In case of nutrient scarcity, larvae associated with L. plantarum develop twice faster than the germ-free ones. However, adjusting development to environmental cues is key to organismal fitness, and yet here animals are growing fast even though the nutritional conditions are poor. We thus questioned whether what seems like an advantage could in turn be deleterious at later stages, and adversely impact adult fitness. We showed that L. plantarum is a true beneficial partner for D. melanogaster throughout the fly life cycle. Indeed, it allows the precocious emergence of mature and fertile adults without fitness drawbacks, and in certain conditions, this commensal can even increase the lifespan of nutritionally challenged males.Broader studies assessing the interaction of Drosophila with several bacterial species can inform about the dynamics of a fly microbiota. Indeed, in the environmental niche bacteria are transferred between the fly and its nutritive substrate, and these reciprocal transfers could alter the composition of the community. We addressed this question using a wild-derived microbial community and observed a high degree of similarity between the bacteria associated with the flies and the composition of the community in the diet, illustrating the stable association of the Drosophila microbiota with the fly population in the niche.Altogether these results emphasize the power of the Drosophila model in the study of the relationships between animals and their microbiota, which allows deciphering the dynamics of commensal bacterial communities and their impact on animal physiology.
78

Rearing programmes for breeding rabbits. Effect of early development and feeding on future reproductive performance of rabbit females and males

Martínez Paredes, Eugenio Melchor 02 September 2019 (has links)
[ES] Cualquier mejora en el conocimiento de la nutrición y el manejo de los futuros conejos reproductores debe considerarse como prioritario en la producción cunícola. Sin embargo, los principales esfuerzos en investigación se han centrado en estos animales durante la fase de reproducción propiamente dicha. La hipótesis inicial de esta tesis fue que alcanzar un desarrollo temprano adecuado durante la gestación, lactancia, engorde y recría, con la ayuda de programas ajustados de alimentación en algunos de estos períodos, mejoraría el rendimiento reproductivo y la vida útil de los futuros conejos reproductores. Para evaluar esta hipótesis, se llevaron a cabo dos tipos de ensayos, tanto en conejos hembra de líneas maternas como en machos de líneas seleccionadas por velocidad de crecimiento y destinadas a la inseminación artificial. El primero de estos ensayos se centró en los diferentes patrones de crecimiento, desde el nacimiento hasta el final de la fase de recría, y su influencia en la carrera reproductiva y la vida útil del conejo. En el segundo tipo de pruebas, se evaluó el efecto del uso de diferentes dietas o programas de alimentación durante el período de recría en la productividad a corto y medio plazo. Los resultados muestran dos fases importantes en el desarrollo temprano, de acuerdo con sus efectos sobre el rendimiento reproductivo y la vida útil. Mostrar un mayor desarrollo corporal desde el nacimiento hasta los 63 días de vida parece tener una influencia positiva en el grado de madurez y la productividad al comienzo de su vida reproductiva, además de poder mejorar su supervivencia a corto plazo, pero con posibles efectos negativos en la esperanza de vida a largo plazo. Sin embargo, el desarrollo durante el período de recría (desde los 63 días de vida hasta el comienzo de la carrera reproductiva) parece tener un mayor impacto en la productividad y la esperanza de vida de nuestros futuros conejos reproductores. Las hembras más engrasadas en la primera inseminación tuvieron tamaños de camada más pequeños y un mayor riesgo de ser sacrificadas que las magras (P<0.05). Además, los machos que mostraron una mayor ganancia media diaria durante el período de recría tuvieron un número y porcentaje de eyaculados viables más bajos a lo largo de su vida productiva y mayor riesgo de muerte o sacrificio. Estos resultados podrían indicar que la clave para llevar a cabo un desarrollo adecuado durante el período de recría debería basarse tanto en conseguir que los conejos alcancen un grado de madurez apropiado, tanto fisiológica como reproductivamente, así como evitar un excesivo engrasamiento al inicio de su vida productiva. En los ensayos destinados a evaluar los programas de alimentación durante la recría, el uso de una restricción alimentaria en hembras, y especialmente el uso de dietas fibrosas (de 8.5 a 10 MJ ED/kg MS) permiten un desarrollo corporal gradual y adecuado a la edad de cubrición, con suficientes reservas corporales para afrontar el comienzo de la vida reproductiva y mejorando tanto su rendimiento reproductivo como su vida útil. El éxito de estos programas de alimentación de recría depende del momento y la duración de la aplicación de estos, mejorándose con la aplicación de un cambio a un pienso enriquecido energéticamente alrededor del primer apareamiento. En los machos, se observó que un programa de alimentación durante la recría adecuado debería adaptarse a la capacidad de ingesta de estos y a sus necesidades nutricionales en períodos concretos de la recría, consiguiendo así mejoras en algunos parámetros del semen al inicio de su vida reproductiva. En conclusión, tanto un desarrollo temprano adecuado desde la gestación hasta el comienzo de su vida reproductiva, como el uso de programas adecuados de alimentación durante la recría podrían mejorar significativamente el rendimiento reproductivo futuro, así como la esperanza de vida, tanto en conejos he / [CAT] Qualsevol millora en el coneixement tant de la nutrició com del maneig dels futurs conills de criança ha de considerar-se com a prioritari en la producció de conills. No obstant açò, els principals esforços en investigació s'han centrat en aquests animals durant la fase de reproducció pròpiament dita. La hipòtesi inicial d'aquesta tesi va ser que aconseguir un desenvolupament primerenc adequat durant la gestació, lactància, engreix i criança, amb l'ajuda de programes ajustats d'alimentació en alguns d'aquests períodes, milloraria el rendiment reproductiu i la vida útil dels futurs conills reproductors. Per a avaluar aquesta hipòtesi, es van dur a terme dos tipus d'assajos, tant en conills femella de línies maternes, com en mascles de línies seleccionades per a la velocitat de creixement i destinades a la inseminació artificial. El primer d'aquests assajos es va centrar en els diferents patrons de creixement, des del naixement fins al final de la fase de criança, i la seua influència en la carrera reproductiva i la vida útil del conill. En el segon tipus de proves, es va avaluar l'efecte de l'ús de diferents dietes o programes d'alimentació durant el període de criança, en la productivitat a curt i mig termini. Els resultats obtinguts semblen indicar que podríem diferenciar dues fases en el desenvolupament primerenc, d'acord amb els seus efectes sobre el rendiment reproductiu i la vida útil. Mostrar un major desenvolupament corporal des del naixement fins als 63 dies de vida sembla tenir una influència positiva en el grau de maduresa i la productivitat al començament de la seua vida reproductiva, a més de poder millorar la seua supervivència a curt termini, però amb possibles efectes negatius en l'esperança de vida a llarg termini. No obstant açò, el desenvolupament durant el període de sembla tenir un major impacte en la productivitat i l'esperança de vida dels nostres futurs conills reproductors. Les femelles més greixades en la primera inseminació van tenir grandàries de ventrada més xicotets (tant nascuts com deslletats) i un major risc de ser sacrificades que les magres (P<0.05). A més, els mascles que van mostrar un major guany mitjà diari durant el període de criança van tenir un nombre i percentatge d'ejaculats viables més baixos al llarg de la seua vida productiva i major risc de mort o sacrifici. Aquests resultats podrien indicar que la clau per a dur a terme un desenvolupament adequat durant el període de criança hauria de basar-se tant a aconseguir que els conills aconseguisquen un grau de maduresa apropiat, per a afrontar els futurs desafiaments productius, com evitar un excessiu greixatge a l'inici de la seua vida productiva. En els assajos destinats a avaluar els programes d'alimentació durant la criança, l'ús d'una restricció alimentària en femelles, i especialment l'ús de dietes fibroses (de 8.5 a 10 MJ ED/kg MS) permeten un desenvolupament corporal gradual i adequat a l'edat de cobriment, amb suficients reserves corporals per a afrontar el començament de la vida reproductiva i millorant tant el seu rendiment reproductiu com la seua vida útil. L'èxit d'aquests programes d'alimentació de criança depèn del moment i la durada de l'aplicació d'aquests, millorant-se amb l'aplicació d'un canvi a un pinso enriquit energèticament al voltant del primer cobriment. En els mascles, es va observar que un programa d'alimentació durant la criança adequat hauria d'adaptar-se a la capacitat d'ingesta d'aquests i a les seues necessitats nutricionals en períodes concrets de la criança, aconseguint així millores en alguns paràmetres del semen a l'inici de la seua vida reproductiva. En conclusió, tant un desenvolupament primerenc adequat des de la gestació fins al començament de la seua vida reproductiva, com l'ús de programes adequats d'alimentació durant la criança podrien millorar significativament el rendiment reproductiu futur, així com l'esperança / [EN] Any improvement on the knowledge of both nutrition and management of the future rabbit breeders should be considered as crucial. However, main research efforts have been focused on animals during reproduction phase. The initial hypothesis of this thesis was that achieving an adequate early development during young rabbits' gestation, lactation, fattening and rearing, with the help of fitted feeding programmes in some of these periods, would be improved reproductive performance and lifespan of the future breeding rabbits. To evaluate this hypothesis, two types of trials, both in rabbit females from maternal lines selected for litter size at weaning and males from paternal lines selected for growth rate and intended on artificial insemination, were carried out. The first of these trials were mainly focused on the different growth patterns, from birth to the end of the rearing age, and their influence on rabbit's reproductive career and lifespan. In a second type of trials, the effect of the use of different diets or feeding programs during the rearing period in the performance in the short- medium-term was evaluated. The results obtained from the evaluation of the different growth patterns trials seem to indicate that, we could differentiate two parts on the early development according to their effects on reproductive performance and lifespan. To show a greater body development from birth to 63 days of life seems to have a positive influence on the maturity degree and productivity at the beginning of their reproductive life, as well as being able to improve their survival in the short-term, but it could be even negative for long-term lifespan. However, the development during the rearing period (from 63 days of life to the beginning of reproduction career) seems to have a higher impact on the productivity and lifespan of our rabbit breeders. Fatter rabbit females at first insemination had smaller litter sizes (born and weaned) and a higher risk of being culled (+13% per positive change in mm of perirenal fat) than lean ones (P<0.05). Also, rabbit males that showed a greater average daily gain during rearing period had a lower number and percentage of profitable ejaculates through it productive life (-10.1 and -4.9% per each 10 g of daily gain increase, respectively; P<0.05) and higher risk of death or culling (+16.2% per each increase in one standard deviation unit on live weight; P<0.05). These results could indicate that the key to carrying out an adequate development during the rearing period should allow the rabbits to reach an appropriate degree of physiological and reproductive maturity to face the future productive challenges, avoiding an excessive fatness at the beginning of their productive life. The use of a feeding restriction in rabbit females, and especially the use of fibrous diets (from 8.5 to 10 MJ DE/ kg DM) lead a gradual and adequate body development at mating, with enough body reserves to face the beginning of reproduction life and improving their whole reproductive performance and lifespan. The success of these rearing feeding programs depends in the moment and duration of application of them and improved with the application of a nutritional flushing around first mating. In rabbit males, it was observed that an adequate rearing feeding program should adapt it to the male's intake capacity and their nutritional requirements rearing period, especially to their high DP needs at the beginning of rearing period or when their requirements were close to maintenance, to improve some semen parameters at the beginning of their reproduction life. In conclusion, both the adequate early development of future rabbit breeders, from their own gestation to the beginning of their reproductive life, and the use of appropriate rearing feeding programs could significantly improve their future reproductive performance, as well as their life expectancy, both in rabbit females and males. / Martínez Paredes, EM. (2019). Rearing programmes for breeding rabbits. Effect of early development and feeding on future reproductive performance of rabbit females and males [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/124969 / TESIS
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Vybrané problémy při oceňování stavebních prací pro účely znaleckých posudků / Selected problems in the process of building operation appraisal for the purposes of expert opinions

Novák, Jindřich January 2018 (has links)
The basic requirement for a good quality expert opinion are high quality sources of information, i.e. adequately detailed and valid groundwork. This dissertation analyzes groundwork for expert activities in the area of building operation appraisals, handling of information and its transmission within the life cycle of a construction. For this purpose, it is possible to divide the construction according to its functional parts. The thesis puts emphasis on drawing up a budget according to its functional parts, which is clearer for the investors, contractors and real estate administrators as well as the expert. A significant part of the dissertation is dedicated to recommendations on how to determine the usual price of building operations. In this section I define some options of how to determine the usual price of building operations, including their comparison. Likewise, I investigated and compared real agreed prices of building contracts for public commissions. The basic recommendation resulting from this chapter is the recommendation for the Czech statistics department to automate the data collection based on registers of building operations created with one of the budgeting programs (preferably according to functional parts). For the experts, I prepared a set of recommendations based on the analyzed differences between the budgeted prices and those applied in real contracts. There is no generally accepted method to evaluate the losses created due to delays in construction. For the purposes of this dissertation, I investigated the common prices of rent of the individual equipment and then established two approaches to put value on the cost of equipping the site, percentage rate and individual calculation. I examine in more detail the issues related to quantification of costs for wintertime arrangements. At the end of the chapter I define recommendations for experts. With regard to recommendations for establishing discounts from the construction price due to occurrence of defects and unfinished tasks, I analyzed real examples of distribution of defects and unfinished tasks at the moment of delivering the building operation to the investor and discovered that approximately 50% of defects are part of the surface working. Additionally, I analyzed the Czech technical regulations regarding surface working in order to find basis for assessment of the presence or absence of a defect. While investigating the approach to non-removable defects, I discovered incorrectly considered shelf life of waterproofing within the appraisal. Based on this, I investigated the market and determined the shelf life of common waterproofing systems. At the end of this dissertation I carry out a comparison of selected items of the two pricing systems most commonly used in the Czech Republic, URS and RTS. The differences are a result of contemplating using different technologies, varied mechanisms and diverse approaches to determine the costs of material.
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Cytoplasmic and Mitochondrial NADPH-Coupled Redox Systems in the Regulation of Aging

Bradshaw, Patrick C. 01 March 2019 (has links)
The reduced form of nicotinamide adenine dinucleotide phosphate (NADPH) protects against redox stress by providing reducing equivalents to antioxidants such as glutathione and thioredoxin. NADPH levels decline with aging in several tissues, but whether this is a major driving force for the aging process has not been well established. Global or neural overexpression of several cytoplasmic enzymes that synthesize NADPH have been shown to extend lifespan in model organisms such as Drosophila suggesting a positive relationship between cytoplasmic NADPH levels and longevity. Mitochondrial NADPH plays an important role in the protection against redox stress and cell death and mitochondrial NADPH-utilizing thioredoxin reductase 2 levels correlate with species longevity in cells from rodents and primates. Mitochondrial NADPH shuttles allow for some NADPH flux between the cytoplasm and mitochondria. Since a decline of nicotinamide adenine dinucleotide (NAD + ) is linked with aging and because NADP + is exclusively synthesized from NAD + by cytoplasmic and mitochondrial NAD + kinases, a decline in the cytoplasmic or mitochondrial NADPH pool may also contribute to the aging process. Therefore pro-longevity therapies should aim to maintain the levels of both NAD + and NADPH in aging tissues.

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