Please read the abstract in the section 02back of this document / Thesis (DVSc)--University of Pretoria, 2010. / Surgery / unrestricted

Top predators can have large effects on community and population dynamics but we still know relatively little about their roles in ecosystems and which biotic and abiotic factors potentially affect their behavioral patterns. Understanding the roles played by top predators is a pressing issue because many top predator populations around the world are declining rapidly yet we do not fully understand what the consequences of their potential extirpation could be for ecosystem structure and function. In addition, individual behavioral specialization is commonplace across many taxa, but studies of its prevalence, causes, and consequences in top predator populations are lacking. In this dissertation I investigated the movement, feeding patterns, and drivers and implications of individual specialization in an American alligator (Alligator mississippiensis) population inhabiting a dynamic subtropical estuary. I found that alligator movement and feeding behaviors in this population were largely regulated by a combination of biotic and abiotic factors that varied seasonally. I also found that the population consisted of individuals that displayed an extremely wide range of movement and feeding behaviors, indicating that individual specialization is potentially an important determinant of the varied roles of alligators in ecosystems. Ultimately, I found that assuming top predator populations consist of individuals that all behave in similar ways in terms of their feeding, movements, and potential roles in ecosystems is likely incorrect. As climate change and ecosystem restoration and conservation activities continue to affect top predator populations worldwide, individuals will likely respond in different and possibly unexpected ways.

Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2017-07-13T14:23:21Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Dissertação de Mestrado Augusto - Versão Final - 05.07.16.pdf: 2539433 bytes, checksum: 5317f34435773775b8fcf0c7526d78d5 (MD5) / Made available in DSpace on 2017-07-13T14:23:21Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Dissertação de Mestrado Augusto - Versão Final - 05.07.16.pdf: 2539433 bytes, checksum: 5317f34435773775b8fcf0c7526d78d5 (MD5) Previous issue date: 2016-05-27 / O pantoprazol é, atualmente, um dos medicamentos mais utilizados para tratamento das doenças gástricas por seu mecanismo de ação conhecido e eficácia comprovada na inibição da secreção de ácido no lúmen estomacal, contudo o tratamento prolongado e os efeitos causados pelas gastropatias exigem tratamentos específicos e mais abrangentes. O material Vegetal Schinus terebinthifolius Raddi, conhecida como Aroeira, já é utilizada popularmente em feridas cutâneas pelos seus efeitos cicatrizantes e anti-inflamatórios, possui vários estudos comprovando sua eficácia na diminuição das lesões promovidas pelas doenças gástricas. Sabendo-se da existência das formulações Associação em Dose Fixa (ADF), que integram em uma mesma fórmula farmacêutica um insumo farmacêutico sintético e um insumo farmacêutico fitoterápico, o objetivo deste trabalho foi elaborar um forma farmacêutica sólida ADF utilizando doses terapêuticas do pantoprazol e do extrato da Aroeira. Para isto, foi realizada a obtenção do granulado seco de aroeira pela metodologia de secagem por convecção. Assim, os ativos foram misturados a excipientes e transformados em comprimidos, por compressão direta. Os comprimidos obtidos foram submetidos a controle físico-químico e foram realizados testes de doseamento, dissolução e estabilidade acelerada que avaliaram as condições da formulação. Como esperado a dissolução demonstrou liberação do pantoprazol em meio básico e degradação em meio ácido, levando a necessidade de utilização do fármaco em formato de grânulos gastroresistentes. Já os testes de estabilidade realizados nos tempos 0, 3 e 6 meses atestou no curto período a manutenção das características básicas de liberação e teor dos comprimidos que foram mantidos durante o estudo em câmara climática de zona IV. Foi possível, desta forma, estabelecer os parâmetros básicos para o desenvolvimento desta formulação ADF contribuindo para a descoberta de alternativas terapêuticas aos tratamentos convencionais. / Pantoprazole is today one of the most used drugs for the treatment of gastric diseases because its known mechanism of action and proven effectiveness in inhibiting acid secretion in the stomach lumen, but prolonged treatment and the effects caused by gastropathy require specific treatments and more extensive. Schinus terebinthifolius Raddi plant, known as Aroeira, is already commonly used in skin healing by its anti-inflammatory effects, having several studies showing efficacy in reducing gastric lesions promoted by the disease. Knowing the existence of the formulations Association-Dose-Fixed (ADF), which are part of the same pharmaceutical form, a synthetic active ingredient and an active herbal principle, the objective of this study was to develop a solid dosage form ADF using therapeutic doses of pantoprazole and the Aroeira extract. For to obtain the dry granulated were used the method for drying by convection, where the active excipients were mixed and tableted by direct compression. The tablets obtained were subjected to physic-chemical control and tests to determinate their concentrations, their accelerated stability and their dissolution quality who served to evaluate the conditions of the formulation. The obtained values maintained their therapeutic range described in the literature. As expected the dissolution demonstrated release of pantoprazole in basic medium and degradation in acid medium that leads to the need to use the drug in gastroresistant granules format. Since the stability testing at 0, 3 and 6 months attested short period maintaining the basic characteristics of release and content of the tablets that were maintained during the study in climate zone IV camera. It was thus possible to establish the basic parameters for the development of this formulation ADF contributing to the discovery of therapeutic alternatives to conventional treatments.

Investigamos a distribuição de ghrelina e de seu receptor (GHS-R) na mucosa gástrica de ratos durante a terceira semana de vida pós-natal e avaliamos o efeito do desmame precoce sobre estas moléculas. Estudamos também a participação da ghrelina no controle da proliferação celular do epitélio gástrico, e para tanto utilizamos a administração de um antagonista. Detectamos o aumento do número de células imunomarcadas para ghrelina nos animais desmamados precocemente e observamos que nem a expressão de GHS-R nem a concentração proteica deste receptor foram alteradas pela mudança da dieta. O uso do antagonista [D-Lys-3]-GHRP-6 resultou na diminuição do índice de síntese de DNA no epitélio gástrico. Concluímos que a ghrelina e o GHS-R estão distribuídos no estômago durante a terceira semana de vida pós-natal e que o desmame precoce aumenta os níveis de ghrelina no epitélio gástrico, sem comprometer seu receptor. Por fim, sugerimos que esta modulação pode estar envolvida no controle da proliferação celular que é fundamental para o desenvolvimento do estômago. / In the present study, we investigated the distribution of ghrelin and growth hormone secretagogue receptor (GHS-R) in the rat gastric mucosa during the third postnatal week, and evaluated the effects of early weaning on these molecules. In addition, we studied whether ghrelin is part of cell proliferation control in gastric epithelium, and to that we used an antagonist. We detected an increase of ghrelin immunolabelled cells in animals submitted to early weaning and observed that GHS-R expression and protein levels of this receptor were not altered by dietary change. The antagonist [D-Lys-3]-GHRP-6 reduced DNA synthesis index. We concluded that ghrelin and GHS-R are distributed in the gastric mucosa during the third postnatal week and that early weaning increases hormone levels in the gastric epithelium, without changing its receptor. We can suggest that such modulation might be involved in the control of cell proliferation, which is essential for stomach development.

Este proyecto se centra en el impacto que genera la elaboración de una bebida que contribuya a la disminución de problemas estomacales como la indigestión o estreñimiento. Algunas de las causas de estos problemas de salud, se relacionan con los factores dietéticos, especialmente la falta de fibra en la alimentación. Otras veces este problema se relaciona enfermedades que padece la persona, especialmente en personas diabéticas y tiroideas. Se analizaron distintos procedimientos para un mejor aprovechamiento de los hongos del kéfir, el cual está compuesto principalmente por bacterias que fermentan el agua. Estos procesos de fermentación de la bebida de desarrollaron cumpliendo las normas de salubridad establecidas y de buenas prácticas de higiene y seguridad ambiental Se realizó un estudio del mercado limeño para conocer los posibles factores claves de la venta, evaluando los puntos socioeconómicos, conductual de los personas en el sector sur de Lima, como los distritos de VES, SJM, Barranco, Chorrillos, y Surco. Por último, se pusieron a la venta las bebidas embotelladas obtenidas del kéfir en dos tipos de sabores; manzana y lima, brindando nuevas alternativas dentro de los productos farmacéuticos contra el estreñimiento, al aprovechar los beneficios nutricionales, bromatológicos que aporta el kéfir. Este proyecto nos permitió concluir con la degustación y ventas de las bebidas fermentadas, ser aceptadas por las personas consumidoras, lo cual demuestra el valor nutricional que tiene el kéfir para su producción, distribución y comercialización para la salud de la flora intestinal. / This project focuses on the impact generated by the development of a beverage that contributes to the reduction of stomach problems such as indigestion, constipation. Some of the causes of these health problems are related to dietary factors, especially the lack of fiber in the diet. Other times this problem is related to diseases that the person suffers, especially in diabetic and thyroid issues. Different procedures were analyzed for a better use of kefir fungi, which is mainly composed of bacteria that ferment water. These beverage fermentation processes were developed in compliance with established health standards and good hygiene and environmental safety practices. A study of the Lima market was carried out to know the possible key factors of the sale, evaluating the socio-economic behavioral points of people in the southern sector of Lima, such as the districts of VES, SJM, Barranco, Chorrillos, and Surco. Finally, bottled beverages obtained from kefir were put up for sale in two types of flavors; apple and lime, providing new alternatives in pharmaceutical products against constipation, taking advantage of the nutritional, bromatological benefits that kefir provides. This project allowed us to conclude with the tasting and sales of fermented beverages, to be accepted by consumers, which demonstrates the nutritional value that kefir has for its production, distribution and marketing for the health of intestinal flora. / Trabajo de investigación

Global warming leads to an increased browning of lakes across the northern hemisphere. This browning can due to benthic light-limitation cause hypoxic bottom conditions which can have negative impact on the fish production in the northern lakes. In this study, I obtained data from a large-scale experiment to test if the removal of anoxic bottom conditions in the hypolimnion affects Eurasian perch (Perca fluviatilis) populations. This was done with a Before-After, Control-Impact design in two adjacent lakes by altering the oxygen conditions in the hypolimnion in one lake while the other remained as control. To analyse if experimental oxygenation of an anoxic hypolimnion altered perch performance, I analysed samples of individual growth (based on back-calculated growth from operculum bone readings), condition, diets and stomach fullness in perch before and after oxygenation from the control and impact lake. The results showed that growth, condition, and stomach fullness increased in the treatment lake but not in the control lake, suggesting that resource availability increased for perch with the removal of anoxic hypolimnion conditions. However, a decline in population abundances was also observed over time within both lakes, which may provide at least an alternative explanation of the observed responses. Still, I hypothesize that the oxygenation at least partially increased the resource abundance in brown lakes, thus increasing fish growth and size.

Introducción: El cáncer de estómago, posee una de las más altas incidencias a nivel mundial. En el Perú, no existe un adecuado registro y reporte de casos, que permita una evaluación de los clásicos y nuevos factores descritos en la literatura, así como de factores propios del carcinoma. Objetivo: Determinar la asociación entre el desarrollo de metástasis en pacientes con adenocarcinoma gástrico y el patrón en anillo de sello. Materiales y Métodos: Ejecutamos un estudio de casos y controles en el Instituto Nacional de Enfermedades Neoplásicas (INEN) en pacientes con diagnóstico de cáncer de estómago. Se definió como caso, a todo paciente que desarrolló metástasis y como control, aquel paciente que no desarrolló metástasis, nuestra exposición de interés fue el tipo de adenocarcinoma. Resultados: Evaluamos 174 casos y 93 controles. La edad promedio en los casos y controles fue de 58,8 y 58,6, respectivamente. El 86,78% de casos y 61,29% de controles fueron diagnosticados en estadios avanzados. Además, se evidenció que los casos presentaron una mayor posibilidad 5,57 veces (IC95%: 1,76 – 17,62) de haber presentado los subtipos anillo de sello en conjunto con otros subtipos histológicos en comparación a los controles. Conclusiones: En pacientes con cáncer gástrico que desarrollaron metástasis, el hallazgo del patrón en anillo de sello no es un factor asociado al pronóstico negativo. Por el contrario, podemos afirmar que en las personas con cáncer gástrico que desarrollaron metástasis es probable que hayan presentado algún patrón histológico que haya co-existido con el subtipo adenocarcinoma en anillo de sello. / Background: Stomach cancer has one of the highest incidences worldwide. In Peru, there is no adequate record and report of cases, which allows an evaluation of the classic and new factors described in the literature, as well as factors typical of carcinoma. Objective: To determine the association between the development of metastasis in patients with gastric adenocarcinoma and the histopathological pattern in signet ring cell. Materials and Methods: We conducted a case-control study at the National Institute of Neoplastic Diseases (INEN) in patients diagnosed with stomach cancer. It was defined as case, to any patient who developed metastases and as a control, that patient who did not develop metastases, our exposure of interest was the type of adenocarcinoma. Results: We evaluated a total of 174 cases and 93 controls. The average age in cases and controls was 58.8 and 58.6, respectively. The majority of cases (86,78%) and controls (61,29%) were diagnosed in advanced stages (greater than 2). Likewise, it was evidenced that the cases presented a greater possibility 5.57 times (IC 95%: 1.76 - 17.62) of having presented the seal ring subtypes in conjunction with other histological subtypes compare to the controls. Conclusions: In patients with gastric cancer who developed metastases, the finding of the signet ring pattern is not a factor associated with the negative prognosis. On the contrary, we can affirm that in people with gastric cancer who developed metastases it is likely that they have presented some histological pattern that has co-existed with the adenocarcinoma subtype in the seal ring. / Tesis

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.

Methods used to estimate the prey consumption by large carnivores include direct continuous observation, stomach content analysis, carcass observations and scat analysis. Continual observations are widely considered the best approach to estimate large carnivore diets, with lions (Panthera leo) being no exception. Continual observation allows the recording of all prey encounters and biases inherent in the other approaches are minimised. However, continuous observations are not always feasible, and in situations where animals cannot be observed at all times, diets are often estimated from observed carcasses. This often leads to an over-estimation of large kills in the estimated diet. Alternative methods that are free of the constraints placed on continuous observations are needed to provide data of a similar quality to that obtained using these continuous observation bouts. I employed a cluster follow up technique to locate lion kills from remotely accessed Global Positioning System (GPS) data from lions in the Kruger National Park (KNP). I develop Generalized Linear Models (GLMs) that increase the probability of locating kills at GPS cluster events. By increasing the predictive ability of detecting kills I show that this technique can be used to locate kills in a more efficient manner than random searching of GPS clusters, with further advantages in that multiple groups of lions can be monitored simultaneously. By incorporating this technique into an adaptive research framework, the diet of lions (and that of other large carnivores) can be estimated. In addition, I show that the spatial association between lions at kill sites, while feeding on carcasses, provides a further increase in the predictive ability of kill site models. Lionesses were found to be considerably closer together at the start of clusters associated with kills in comparison to clusters where no kill was found. This pattern remained consistent for both small and large kills. This proximity approach could therefore be incorporated into the GLMs that are developed to predict kill sites of large social carnivores. To further reduce the bias (where small kills are often missed) inherent in carcass observations, I combined scats and carcasses collected from known times, locations and lion groups to construct a temporal kill record for each group of lions. By combining scats and carcasses I estimate that at least 50% of the small prey items, namely impala (Aepyceros melampus) and warthog (Phacochoerus africanus) were missed when GPS clusters were investigated for carcasses. Ultimately, I show that a combination of GPS cluster investigations based on models developed using GPS movement data in combination with lion proximity data, augmented with scats collected at GPS clusters, could provide estimates of large carnivore diets that begin to approach estimated diets obtained through continuous monitoring. The resulting diet, estimated from the GPS cluster approach in combination with scat collection, indicated that the dominant prey item in the region was zebra (Equus quagga) followed by wildebeest (Connochaetes taurinus), impala and buffalo (Syncerus caffer). Selection indices for the eight dominant prey items were calculated using prey availability measures obtained from the aerial census data and ground counts of groups. It has been suggested that group level selection is a better approach to calculating predator-prey interactions, and that stability in predator-prey systems is improved if group metrics of prey are used as apposed to individual measures of availability. I show that there is a considerable shift in selection indices, as well as in the order that prey is selected, when using different measures of prey availability. In selection studies, more effort needs to be paid to the assessment and definition of prey availability to ensure results accurately reflect selection patterns in the field, especially when data are used for the development of management practices. Combining buffalo predation data collected from GPS cluster investigations with buffalo mortality data collected over five years prior to the commencement of the GPS cluster investigations, allowed an investigation into patterns of lion predation on buffalo between 2000 and 2007. Buffalo of both sexes were more vulnerable to predation in habitats that gave lions an ambush advantage (i.e. increased grass height and tree density). Despite this similarity in landscape risk, different processes lead to similar fates in dangerous habitats for buffalo of both sexes. Predation pressure by lions on buffalo increased following periods of reduced rainfall; with more buffalo predated on following drier six month periods. Predation on males constituted a significant proportion of all predation and was focused predominantly into the late dry season. The resulting method of locating kills by using GPS clusters and correcting carcass data with scats collected along the movement path represents a robust technique to estimate large carnivore diets. In the concluding chapter I present avenues where future research can build on the current thesis and present a framework that can be employed when attempting to estimate large carnivore diets. / Thesis (PhD)--University of Pretoria, 2010. / Zoology and Entomology / unrestricted

Homeostatic self-regulation is a fundamental aspect of open dissipative systems. Integral feedback has been found to be important for homeostatic control on both the cellular and molecular levels of biological organization and in engineered systems. Analyzing the task allocation mechanisms of three insect societies, we identified a model of integral control residing at colony level. We characterized a general functional core mechanism, called the “common stomach,” where a crucial shared substance for colony function self-regulates its own quantity via reallocating the colony’s workforce, which collects and uses this substance. The central component in a redundant feedback network is the saturation level of this substance in the colony. An interaction network of positive and negative feedback loops ensures the homeostatic state of this substance and the workforce involved in processing this substance. Extensive sensitivity and stability analyses of the core model revealed that the system is very resilient against perturbations and compensates for specific types of stress that real colonies face in their ecosystems. The core regulation system is highly scalable, and due to its buffer function, it can filter noise and find a new equilibrium quickly after environmental (supply) or colony-state (demand) changes. The common stomach regulation system is an example of convergent evolution among the three different societies, and we predict that similar integral control regulation mechanisms have evolved frequently within natural complex systems.