O pentilenotetrazol (PTZ) é um agente convulsivo amplamente utilizado em modelos animais para investigações envolvendo crises convulsivas. Embora haja um crescente número de estudos envolvendo zebrafish adulto e convulsão, não há até o momento uma caracterização comportamental detalhada do modelo de indução de crises por PTZ neste animal. Portanto, o objetivo deste estudo foi realizar uma caracterização detalhada das manifestações comportamentais no modelo de convulsão induzida por PTZ em zebrafish adulto. Grupos de 12 animais foram submetidos, por imersão, a distintas diferentes concentrações de PTZ (5, 7.5, 10 e 15 mM). O comportamento convulsivo foi observado durante 20 minutos. Os animais apresentaram os seguintes escores comportamentais: (0) nados curtos; (1) aumento na atividade natatória e na abertura opercular; (2) movimentos erráticos e acelerados; (3) movimentos circulares; (4) convulsão clônica; (5) convulsão tônica; (6) morte. Os animais expostos a diferentes distintas concentrações de PTZ apresentaram diferentes distintos perfis convulsivos, intensidades de convulsão e latência para chegar aos escores. Apenas os animais imersos na concentração de 15 mM apresentaram maior tempo para retornar ao comportamento normal após a exposição ao PTZ. A mortalidade foi de 33% e 50% para as concentrações de 10 mM e 15 mM, respectivamente. No intuito de avaliar abordagem perfil comportamental frente ao pré-tratamento de um fármaco anticonvulsivo, 12 animais foram expostos a diazepam (DZP) por 40 min e após expostos ao PTZ (10 mM). O tratamento com DZP atenuou a severidade da convulsão, mas não o tempo necessário para retornar ao comportamento normal. Levando em consideração que este modelo baseia-se na imersão direta do animal a uma solução de PTZ, avaliamos também as concentrações cerebrais deste agente convulsivo. Além disso, investigamos também uma possível correlação entre a concentração cerebral de PTZ, o tempo e a concentração de exposição. Os resultados decorrentes da exposição dos animais a 5 e 10 mM de PTZ, apontam para uma correlação tempo e concentração dependentes. Os resultados deste trabalho demonstram uma caracterização comportamental detalhada ao longo do tempo de exposição ao PTZ, além de avaliar pela primeira vez a intensidade de convulsão, tempo de retorno ao comportamento normal e mortalidade dos animais. Além disso, pela primeira vez foram determinadas as concentrações cerebrais deste composto neste modelo de convulsão em zebrafish adulto. Por fim, espera-se que tais ferramentas comportamentais e de quantificação cerebral deste composto possam ser úteis em futuras investigações translacionais e estudos que tenham como objetivo melhor compreender esta desordem. / Pentylenetetrazole (PTZ) is a common convulsant agent used in animal models to investigate the mechanisms of seizures. Although adult zebrafish have been recently used to study epileptic seizures, a thorough characterization of the PTZ-induced seizures in this animal model is missing. The goal of this study was to perform a detailed temporal behavior profile characterization of PTZ-induced seizure in adult zebrafish. The behavioral profile during 20 min of PTZ immersion (5, 7.5, 10, and 15 mM) was characterized by stages defined as scores: (0) short swim, (1) increased swimming activity and high frequency of opercular movement, (2) erratic movements, (3) circular movements, (4) clonic seizure-like behavior, (5) fall to the bottom of the tank and tonic seizure-like behavior, (6) death. Animals exposed to distinct PTZ concentrations presented different seizure profiles, intensities and latencies to reach all scores. Only animals immersed into 15 mM PTZ showed an increased time to return to the normal behavior (score 0), after exposure. Total mortality rate at 10 and 15 mM were 33% and 50%, respectively. Considering all behavioral parameters, 5, 7.5, 10, and 15 mM PTZ, induced seizures with low, intermediate, and high severity, respectively. Pretreatment with diazepam (DZP) significantly attenuated seizure severity. Finally, the brain PTZ levels in adult zebrafish immersed into the chemoconvulsant solution at 5 and 10 mM were comparable to those described for the rodent model, with a peak after a 20-min of exposure. The PTZ brain levels observed after 2.5-min PTZ exposure and after 60-min removal from exposure were similar. Altogether, our results showed a detailed temporal behavioral characterization of a PTZ epileptic seizure model in adult zebrafish. These behavioral analyses and the simple method for PTZ quantification could be considered as important tools for future investigations and translational researches.

The chief objective of the study was to investigate the population dynamics of the hyrax in the Mountain Zebra National Park (MZNP). To realise this objective information on growth, age determination, reproduction, habitat utilization, behaviour, parasites and mortality had to be gathered. The growth of hyrax in relation to age is described by means of Stevens asymptotic regression equations. Near asymptotic measurements are attained first in hind foot length (at 30-33 months of age), head/body length (at 37-39 months of age), girth (at 41-48 months of age) and body mass (at 68-70 months of age). Allometric growth of the various body measurements was investigated and useful predictive relationships for mass are presented. Age determination of hyrax was studied in detail. Cementum annuli counts provided reliable estimates of age. One primary cementum line is formed annually. The dried eye lens mass was an accurate means of age determination up to c. 72 months of age. A summary of findings which will facilitate age determination of dead animals or skulls, and live animals, is provided. Reproduction in the hyrax was studied with emphasis on breeding season, age-specific litter sizes, prenatal mortality and lactation. Male hyrax attained puberty at 15-17 months of age or one year later. Females generally attained puberty at 15-17 months of age. One female (1,4% of total shot sample for the specific age group) attained puberty at 4-5 months of age. Middle-aged hyrax had significantly larger litter sizes than younger animals. Hyrax in the MZNP feed on at least 80 different plant species belonging to 33 plant families. Crude protein of stomach contents and faecal samples showed little seasonal fluctuation implying that hyrax in the MZNP were on a stable quality diet. Female hyrax enjoyed a significantly better quality diet than males for the four month period prior to parturition and during the first two months of lactation. The crude protein values of faecal and stomach samples had a significant correlation. Body fat of male and female hyrax showed seasonal variation related to physiologically stressful periods. Seasonal differences in activity patterns were demonstrated. The basic structure of hyrax social organization is the multi-female kinship group that is matrilocal. Territorial dominant males maintain harems and exclude all other adult males. Peripheral males occupy areas on the periphery of the activity areas of other members of the hyrax colony. Peripheral males do not form bachelor groups and are normally younger than territorial males. It is suggested that territorial males are able to monopolize between 3-17 females in a successful and energetic manner. Both natal and breeding dispersal occurred, the former being considerably more extensive than the latter. The ecto- and endoparasites of hyrax were identified and their burdens quantified over a 13 month period. Juveniles had significantly larger burdens of ectoparasites than did adults. Information on age-specific mortality was obtained from skulls collected in the field and at black eagles' nests. Losses that occurred in the study population due to caracal and black eagle predation were quantified. Evidence is supplied which indicates that juvenile mortality may fluctuate markedly. The population dynamics of the hyrax population in the MZNP was studied by the use of time specific life-tables, models on population growth rates, population simulation models and sensitivity analysis. Sensitivity coefficients were used as a predictor of population regulation. Female juvenile mortality was considered to be the main regulating factor. Changes in fecundity schedule are important compensatory mechanisms and also play an important role in the regulation of a hyrax population. Predation, particularly by caracal, is thought to dampen population fluctuations.

The objective of this research is to develop suitable models to simulate and analyse Electrical Vehicle (EV) power-trains to identify and improve some of the deficiencies of EVs and investigate new system architectures. Although some electro-chemical batteries improvements have lately been achieved in specific-energy, the power density is still low. Therefore, an efficient, cost-effective and high power density support unit could facilitate EV competitiveness compared to conventional internal combustion engine powered vehicles in the near future. The Na-Ni-Cl2, or ZEBRA battery as it is most commonly known, has good energy and power densities; it is very promising electro-chemical battery candidate for EV's. The thesis presents a detail simulation model for the ZEBRA technology and investigates its application in an EV power-train with regard to state-of-charge and voltage transients. Unlike other battery systems, the ZEBRA technology can sustain about 5-10% of failed cells. While this is advantageous in single series string or single battery operation it is problematic when higher numbers of batteries are connected in parallel. The simulation model is used to investigate faulted operation of parallel battery configurations. A non-linear capacitance versus voltage function is implemented for the supercapacitor model which yields good energy and terminal voltage predictions when the supercapacitor is cycled over dynamic regimes common to EV applications. A thermal model is also included. Multiple energy source systems are modelled and studied in the form of an energy dense ZEBRA battery connected in parallel with a power dense supercapacitor system. The combination is shown to increase available power, reduce the maximum power demanded from the battery and decrease battery internal power loss. Consequently, battery life would be increased and more energy would be recovered from regenerative braking, enhancing the energy conversion efficiency of the power-train.A combination of ICE and ZEBRA battery is implemented as a range extender for London taxi driving from Manchester to London. The hybridisation ratio of the system is discussed and applied to fulfil the requirement with minimum emissions. This study offers a suitable model for different energy sources, and then optimises the vehicle energy storage combination to realize its full potential. The developed model is used to assess different energy source combinations in order to achieve an energy efficient combination that provides an improved vehicle performance, and, importantly, to understand the energy source interconnection issues in terms of energy flow and circuit transients.

Orientador: Ana Marisa Fusco Almeida / Coorientador: Paulo Cesar Gomes / Banca: Mario Sergio Palma / Banca: Claudia Vianna Maurer Morelli / Banca: Tais Maria Bauab / Banca: Rosemeire Cristina Linhari Rodrigues Pietro / Resumo: Devido ao aumento das doenças fúngicas, do uso indiscriminado de antimicrobianos, associados ao aparecimento de cepas resistentes e formadoras de biofilmes, é essencial a busca pelo desenvolvimento de novos antifúngicos mais eficientes. As espécies de Candida são conhecidas pela capacidade de infectar humanos, sendo a formação de biofilmes um dos fatores de virulência mais importantes. No estudo interação patógeno-hospedeiro, bem como para eficácia terapêutica e segurança, algumas vantagens no uso de modelos animais alternativos são a redução de tempo de resposta em experimentos, eficiência e baixo custo quando comparado ao uso de camundongos. Desta forma, moléculas antifúngicas estão sendo testadas nestes animais alternativos, como Danio rerio (Zebrafish), um vertebrado que apresenta rápida reprodução e homologia genética e funcional com os mamíferos. Em relação às moléculas em testes, há um crescente estudo de peptídeos oriundos de venenos e da hemolinfa de insetos, como novos compostos antifúngicos, os quais possam apresentar além de boa atividade, baixa toxicidade e não-teratogenicidade. Neste trabalho, foram estudados peptídeos análogos de Mastoparanos de vespas (MKs) cuja atividade antimicrobiana já é conhecida, previamente sintetizados com modificações nas suas características estruturais, como número de resíduos de Lisina e carga líquida. Levando em consideração as características estruturais dos MKs, outros quatro peptídeos foram sintetizados e estudados, dos quais d... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Due to the increase of fungal diseases, indiscriminate use of antimicrobial linked to occurrence of resistance and biofilm - forming strains, the search for the development of new efficient antifungals is essential. Candida species are known for their ability to infect humans, and biofilm formation is one of the most important virulence factors. In respect pathogen - host interaction, as well as for therapeutic efficacy and safety, some advantages in the use of alternative animal models are the reduction of response time in experiments, efficiency and low cost when compared to the use of mice. Thus, antifungal molecules are being tested in these alternative animals, such as Danio rerio (Zebrafish), a vertebrate that exhibits rapid reproduction and genetic and functional homology with mammals. Regarding molecules under test, there is a growing study of peptides from poisons and insect hemolymph, as new antifungal compounds, which may present aside from to good activity, low toxicity and non-teratogenicity. In this work, it was studied was mastoparan analog peptides (MKs), whose antimicrobial activity is already known, previously synthesized with modifications in their structural characteristics, such as Lysine residues number and net charge. Taking into account the structural characteristics of MKs, four other peptides were synthesized and studied, of which two peptides (PepM1; PepM2) are analogues of the antimicrobial Moricin C3, derived from Galleria mellonella hemolymph, an... (Complete abstract click electronic access below) / Doutor

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The following is a book of poetry, born of the chaos in leaving home and discovering loneliness within the confines of my own body. Sustaining a mixed vernacular, that of the rural Midwest, the Bible, medicine, and the strange, this book seeks a sympathy with illness and with those who suffer its symptoms. I drew much upon my childhood in particular the years spent going on rounds with my father at the local hospital.

It can be difficult to guide yourself across a crosswalk when your visual capabilities are limited, which can be an everyday issue for someone with impaired vision. This paper aims to alleviate that issue for zebra stripe crosswalks by proposing an algorithm that incorporates multiple properties of zebra stripe crosswalks with a neural network to assist in quickly and accurately identifying a crosswalk in video and pictures taken from a smartphone camera. This method improves the accuracy of zebra crosswalk detection in images. In a large dataset, it correctly identified 76.5% of zebra crosswalks, while reducing the false discovery rate (q-value) from 20% without using neural networks to 2.21% using this neural network method. Only 2.04% of non-crosswalk images as crosswalks using the neural network method.

Eukaryotic platelets are small cell fragments that are released into the bloodstream from megakaryocytes, and their production is initiated in the bone marrow. They are mainly involved in blood hemostasis and thrombus formation. The newly synthesized platelets are called reticulated platelets or young platelets. Zebrafish thrombocytes are equivalent to mammalian platelets and have similar characteristics and functions. Likewise, zebrafish has both young and mature thrombocytes. Only young thrombocytes as reticulated platelets are labeled with thiazole orange. Similarly, labeling zebrafish thrombocytes with a specific concentration of DiI-C18 showed two populations of thrombocytes (DiI+ and DiI-). Again, only young thrombocytes showed DiI+ labeling. The mechanism of selective labeling of young thrombocytes by is unknown. Furthermore, there is no zebrafish line where young and mature thrombocytes are differentially labeled with fluorescence proteins. Therefore, in this study, we identified and confirmed that the RFP labeled cells of Glofish were young thrombocytes. In addition, we found that myosin light chain 2 (MLC2) promoter is expressed in young thrombocytes. We also generated a transgenic zebrafish line, GloFli fish, where the young and mature thrombocytes are labeled with red and green fluorescence proteins respectively. Furthermore, this study showed a two-fold increase in glycerol-phospholipids (GP) in mature thrombocytes compared to young thrombocytes suggesting the lipid composition may be important for differential labeling. Therefore, we tested the liposomes prepared with different ratios of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) and observed that the lower amounts of PE favor the DiI-C18 labeling whereas higher concentrations of PC are less efficient. Also, in both PE and PC, increased concentrations of both resulted in decreased binding. These results are consistent with our observation that mature thrombocytes have higher concentrations GP and thus DiI-C18 may not bind to them efficiently compared to young thrombocytes.

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