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DISTRIBUIÇÃO E OCORRÊNCIA DE PINÍPEDES NA ILHA ELEFANTE, SHETLANDS DO SUL, ANTÁRTICA ENTRE 2005 E 2010 A PARTIR DE CENSOS AÉREOS / DISTRIBUITION AND OCCURENCY OF PINNIPEDS IN THE ELEPHANT ISLAND, SOUTH SHETLANDS ISLANDS, ANTARCTICA, BETWEEN 2005 AND 2010 FROM AERIAL CENSUSESTrevisan, Mariana Borba 15 May 2015 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Pinnipeds are marine mammals of the Carnivora order. Some species were close to the complete extinction due to predatory hunt for their skin and blubber. Conservation measures have been taken to avoid extinction and population monitoring is essential to evaluate how populations are responding along the years. Remote sensing, from satellite images and aerial photographs, allows the monitoring through individual counting without interfering directly in the animals. The main objective of this work is to analyze aspects of the demography and the distribution of pinnipeds in the Elephant Island, located northeast of the Antarctic Peninsula, in the South Shetlands Islands, during the Austral summer (November to March) in the years of 2005 to 2010, using aerial censuses performed around the Elephant Island. The aerial censuses photographs were taken from Squirrel helicopters of the Brazilian Navy flying at a constant speed, 30 to 50 meters height along the island s perimeter. The data were obtained by counting the individuals registered in the photographs. The counting of all censuses summed 27.592 individuals along the years. Due to the fact that it was not possible to cover the totality of the island s perimeter in all censuses, the distribution and occurrence were studied dividing the island into seven sectors along its total perimeter. In general, the species observed more frequently in all sectors were the Southern elephant seals (Mirounga leonina) and Antarctic fur seals (Artocephalus gazella). Even though other seals species such as the Weddell seal (Leptonychotes weddelli), the leopard seal (Hydrurga leptonyx) and the crabeater seal (Lobodon carcinophaga) registered to the Elephant Island exhibited low representativeness in their occupancy, their presence is constant in all censuses. Using the statistical technique Principal Coordinates Analysis, we notice that the occupancy pattern of the Elephant
Island by the pinnipeds is related to the substrate present in the different sectors of the island and to the period of the Austral summer sampled. Southern elephant seals settle in sectors of sandy substrate and exhibit the largest occupation during the earlier months of summer (November and December), while Antarctic fur seals preferably settle in rocky substrates and its occupancy is larger during the latest months of summer (January to February). New breeding sites were described in particular for the Antarctic fur seals in so called sectors of Valentin and Piloto Pardo. Preliminary data taken from satellite images of Valentin sector corroborated the aerial photograph data and indicated that the Antarctic fur seals are the predominant species in this region. To our knowledge, this is the first study taken with aerial censuses data in the Elephant Island, and the results presented here have great use for the correct management and conservation politics for the pinnipeds. / Pinípedes são mamíferos marinhos pertencentes à Ordem Carnívora. Algumas espécies foram levadas quase à extinção devido à caça por sua pele e gordura. Medidas de conservação foram tomadas para evitar a extinção e o monitoramento das populações é essencial para avaliar como estas estão reagindo ao longo dos anos. O sensoriamento remoto através de imagens de satélite e fotografias aéreas permite este monitoramento através da contagem dos indivíduos sem interferir diretamente com os animais. Este trabalho tem por objetivo geral analisar aspectos da distribuição e ocorrência de pinípedes na Ilha Elefante, situada a nordeste da Península Antártica no Arquipélago das Shetlands do Sul, durante o verão austral (novembro a março) entre os anos de 2005 a 2010 através de censos aéreos realizados no entorno da Ilha Elefante. As fotografias de censo aéreo foram tomadas a partir de helicópteros Esquilo da Marinha do Brasil voando em velocidade constante, entre 30 e 50 m de altura ao longo do perímetro da ilha. Os dados foram obtidos através da contagem de indivíduos registrados nas fotografias. Os animais contados a partir dos censos somados atingiram 27.592 indivíduos ao longo dos anos. Devido ao fato de que não foi possível cobrir todo o perímetro da ilha em todos os censos aéreos, a distribuição e abundância foram estudadas dividindo-se a ilha em sete setores ao longo de seu perímetro total. Em geral, as espécies observadas com maior frequência em todos os setores foram os elefantes-marinhos do sul (Mirounga leonina - EMS) e os lobos-marinhos antárticos (Artocephallus gazella - LMA). Ainda que os demais focídeos como a foca-de-Weddell (Leptonychotes weddelli), foca-leopardo (Hydrurga leptonyx) e a foca-caranguejeira (Lobodon carcinophaga) registrados para a Ilha Elefante apresentem baixa representatividade na sua ocupação, sua presença é constante em todos os censos. Utilizando técnica estatística de Análise de Coordenadas Principais, nota-se que o padrão de ocupação da Ilha Elefante pelos pinípedes está relacionado com o substrato presente nos diferentes setores da ilha. Os EMS permanecem em locais de substrato arenoso e apresentam maior ocupação nos primeiros meses do verão (novembro e dezembro), enquanto os LMA permanecem preferencialmente em locais rochosos e sua ocupação é maior nos últimos meses de verão (janeiro e fevereiro). Novos locais de reprodução foram descritos em especial para LMA nos setores denominados de Valentin e Piloto Pardo. Dados preliminares tomados a partir de uma imagem de satélite para o setor de Valentin corroboraram os dados de fotografias aéreas e indica que LMA é a espécie predominante dessa região. Ao nosso conhecimento, esse é o primeiro estudo realizado com dados de censo aéreo na Ilha Elefante e os resultados apresentados aqui tem grande utilidade para o correto manejo e para as políticas de conservação de pinípides.
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Adequação protéica em rações com pastagens ou com cana-de-açúcar e efeito de diferentes intervalos entre desfolhas da pastagem de capim Elefante sobre o desempenho lactacional de vacas leiteiras / Protein adequacy of diets for lactating dairy cows grazing pasture or fed chopped sugarcane and effect of interval between defoliation of Elephant grass pasture on lactational performance of dairy cowsTadeu Vinhas Voltolini 24 April 2006 (has links)
No presente estudo foram efetuados três ensaios. No primeiro, foram comparados os efeitos de teores crescentes de proteína metabolizável (PM), de acordo com o NRC (2001) para vacas lactantes mantidas em pastagens de capim Elefante. Os aumentos em PM foram obtidos com o aumento da proporção de farelo de soja na ração. Foram utilizadas 12 vacas, delineadas em quadrado latino 3 x 3 com quatro repetições, durante 60 dias de avaliação. Não foi observado efeito (P>0,05) sobre a produção de leite e leite corrigido para 3,5% de gordura, teores e produção de gordura, proteína e sólidos totais. Houve aumento linear (P<0,05) nos teores de nitrogênio uréico no leite (11,17; 13,17; 15,63 mg dL-1) e no plasma (18,57; 19,93; 21,99 mg dL-1). No segundo ensaio, foram avaliados os efeitos de dois diferentes intervalos entre desfolhas (95% de interceptação de luz pelo dossel T1 e 27 dias fixos T2) das pastagens de capim Elefante sobre o desempenho lactacional de vacas leiteiras. Foram utilizadas oito vacas lactantes, delineadas em cross-over, durante 80 dias. Os dados das pastagens foram analisados através de delineamento inteiramente casualizado com medidas repetidas no tempo. Foi observado maior (P<0,05) altura do dossel em pré (1,03 e 1,21m) e pós-pastejo (0,62 e 0,71m), interceptação de luz pelo dossel (95,47 e 97,91%), teor de fibra em detergente ácido (35,88 e 37,05%) e fibra em detergente neutro (65,08 e 66,99%). Não houve efeito dos tratamentos (P>0,05) sobre a massa de forragem em pré (6.270 e 6.310 kg de MS ha-1) e pós-pastejo (3.580 e 3.850 kg de MS ha-1). Houve tendência de maior produção de leite (16,72 e 14,09 kg dia-1), produção de gordura (0,64 e 0,54 kg dia-1), lactose (0,72 e 0,58 kg dia-1) e de sólidos totais (2,04 e 1,70 kg dia-1) para o T1 em comparação com o T2. No terceiro estudo, foram avaliados os efeitos de três estratégias de suplementação protéica nas rações (isoprotéicas) com cana-de-açúcar para vacas em lactação, em dois níveis de produção, 18 kg dia-1 (T1, T2 e T3) e 10 kg dia-1 (T4, T5 e T6). No T1 e T4, foi usado o teor de 1 kg de uréia para cada 100 kg de cana-de-açúcar in natura, no T2 e T5 as rações foram formuladas com teores ajustados de PM, enquanto no T3 e T6 havia teores excessivos de PM, conforme o NRC (2001), através do aumento em farelo de soja e redução na uréia. Para a análise dos dados foi utilizado o delineamento em quadrado latino 3 x 3 com três replicações. Não houve efeito dos tratamentos (P>0,05) sobre o consumo de matéria seca, produção de leite, teor de gordura, proteína e sólidos totais. Também não houve efeito dos tratamentos (P>0,05) sobre os teores de nitrogênio uréico no leite (13,42; 13,26; 14,03 e 13,62; 13,48; 14,12 mg dL-1) e no plasma (19,03; 19,22; 20,02 e 19,23; 19,32 e 20,12 mg dL-1), para ambos os grupos avaliados. / In the present study three trials were conducted. Trial 1: Three concentrates with increasing metabolizable protein (MP) contents were fed to lactating dairy cows grazing Elephant grass. Extra soybean meal was fed to increase MP in the diet beyond NRC (2001) recommendation. Twelve cows were used in a 3 x 3 latin square design, replicated four times, for 60 days. There were no effects (P>0.05) of treatments on milk yield, 3,5% fat corrected milk, on fat, protein and total solids contents and yields. Milk urea nitrogen and plasma urea nitrogen concentrations increased linearly (P<0.05)(11.17; 13.17; 15.63 and 18.57; 19.93; 21.99 mg dL-1) with increasing concentrate crude protein content. Trial 2: Two different intervals between defoliation (95% of light interception T1 and 27 days fixed T2) of Elephant grass pasture were compared for lactating dairy cows. Eight cows were used in a cross-over design during 80 days. The pasture data were analyzed in a complete random design with time repeated measurements. The sward heights pre-grazing (1.03 and 1.21m), and post-grazing (0.62 and 0.71m), light interception (95.47 and 97.91%), acid detergent fiber (35.88 and 37.05%) and neutral detergent fiber (65.08 and 66.99%) were higher for T2 compared to T1. Forage mass pre-grazing (6270 and 6310 kg DM ha-1) and post-grazing (3580 and 3850 kg DM ha-1) were not affected by treatments (P>0.05). There were tendencies for higher milk yield (16.72 and 14.09 kg day-1), fat yield (0.64 and 0.54 kg day-1), lactose yield (0.72 and 0.58 kg day-1) and total solids yield (2.04 and 1.70 kg day-1) for T1 in comparison with T2. Trial 3: Three strategies for protein adequacy in sugarcane based diets were compared for lactating dairy cows producing 18 kg milk day-1 (T1, T2 and T3), or 10 kg of milk day-1 (T4, T5 and T6). In treatment 1 (T1 and T4) urea was added to the diets in the dose of 1% of sugarcane (as fed), as traditionally done in Brazil. In treatment 2 (T2 and T5), diets were formulated according to NRC (2001) to be adequate in MP. In treatment 3 (T3 and T6), MP was fed in excess of NRC (2001) recommendation. All the three diets were isonitrogenous. Increasing soybean meal and decreasing urea in the diets was done to increase MP. Eighteen dairy cows, separated in two groups (10 and 18 kg milk-1 day-1) with nine cows each, were used during sixty days, in a 3 x 3 latin square design replicated three times. There were not effects of treatments (P>0.05) on DMI, milk yield, fat contents and yields, protein contents and yields and total solids contents and yields. There were not effects of treatments (P>0.05) on milk urea nitrogen (13,42; 13,26; 14,03 e 13,62; 13,48; 14,12 mg dL-1) and plasma urea nitrogen (19.03; 19.22; 20.02 and 19.23; 19.32 e 20.02 mg dL-1).
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Avaliação de clones de Pennisetum sp. para a produção de silagemSANTOS, Rerisson José Cipriano dos 11 February 2010 (has links)
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Previous issue date: 2010-02-11 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The experiment was carried out at the experimental Station of Itambé-PE from the
Agronomic Institute of Pernambuco, the objective was to evaluate forages and silages
of different clones of Pennisetum sp.,cut at 56 days of regrowt. Treatments were five
clones of Pennisetum sp. (IPA HV 241, IPA/UFRPE A-146 2.37, IPA/UFRPE A-2.114,
Elephant B and Mott), using a complete randomized block design with four replications.
Experimental PVC silos were opened after 90 days of storage and chemical analysis
were performed responses variable determined included dry matter (DM) concentration,
crude protein (CP), ashes (CZ), neutral detergent fiber (NDF), acid detergent fiber
(ADF), hemicelluloss (HEM), neutral detergent insoluble nitrogen (NDIN), and acid
detergent insoluble nitrogen (ADIN), besides pH, ammoniacal nitrogen, buffering
capacity, soluble carbohydrates, and the organoleptic features of the silages were
perfomed. Calculations of losses by effluents, gases and dry matter recovery were
perfomed. Forages before ensiling showed significant differences (P<0,005) for dry
matter concentration, NDIN, soluble carbohydrates, and in vitro DM digestibility.
Silages of the same forages, however, did not present significant differences for most of
the variables related to chemical composition (NDF, ADF, hemicelluloss, ashes, pH,
ammoniacal nitrogen, effluents and gases). In general, the grass elephant of size dawn
IPA/UFRPE TAIWAN A-146 2.37, showed a better quality of silage with better dry
matter contend and coefficient of fermentation. All other clones of Pennisetum sp.
showed efficiency in the fermentation process, despite the reduced levels of DM. / O experimento foi conduzido na Estação Experimentalde Itambé-PE, pertencente ao Instituto Agronômico de Pernambuco, objetivando avaliar forragens e silagens de diferentes clones de Pennisetum sp., cortado aos 56 dias de idade. Os tratamentos foram constituídos de cinco clones de Pennisetum (IPA HV 241, IPA/UFRPE Taiwan A-146 2.114, IPA/UFRPE Taiwan A-146 2.37, Elefante B e Mott), em delineamento em blocos casualizados, com quatro repetições. Utilizou-se PVC, com abertura após 90 dias de armazenamento, para avaliação de matéria seca (MS), proteína bruta (PB), cinzas (CZ), fibra em detergente neutro (FDN), fibra em detergente ácido (FDA), nitrogênio insolúvel em detergente neutro (NIDN), nitrogênio insolúvel em detergente ácido (NIDA), pH, nitrogênio amoniacal, poder tampão, carboidratos solúveis coeficiente de fermentação e as características organolépticas das silagens na abertura dos silos. Foram realizados cálculos de perdas por efluentes, gases e recuperação de matéria seca. Para as forragens, antes de ensilar, observou-se diferenças significativas (P<0,05) para o teor de matéria seca, nitrogênio insolúvel em detergente ácido (NIDA), nitrogênio insolúvel em detergente neutro (NIND), carboidratos solúveis, Coeficiente de fermentação e digestibilidade in vitro. Em relação às silagens, observou-se a não ocorrência de diferenças significativas na maioria das características da composição química (FDN, FDA, hemicelulose, cinza, pH, nitrogênio amoniacal, efluentes e gases). De maneira geral, o capim elefante de porte baixo, IPA/UFRPE TAIWAN A-146 2.37, apresentou melhor qualidade da silagem com melhor teor de MS e melhor coeficiente de fermentação. Todos os demais clones de Pennisetum sp. apresentaram eficiência no processo fermentativo, apesar dos teores reduzidos de MS.
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Analise de ciclo de vida aplicada ao processo produtivo de ceramica estrutural tendo como insumo energetico capim elefante (Pennisetum Purpureum Schaum) / Life cycle assessment applied to the productive process of structural ceramic tends as input energy elephant grass (Pennisetum Purpureum Schaum)Seye, Omar 22 October 2003 (has links)
Orientador: Luis Augusto Barbosa Cortez / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-08T11:20:54Z (GMT). No. of bitstreams: 1
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Previous issue date: 2003 / Resumo: Para alcançar o desenvolvimento sustentável a energia tem um papel chave, sendo responsável por boa parte da poluição em todas as atividades humanas. O uso de energias renováveis é altamente desejável quando se quer reduzir ou eliminar essa poluição sem perder a oportunidade de desenvolvimento de uma atividade produtiva qualquer. No presente trabalho delimitou-se a atividade alvo como sendo o processo produtivo de cerâmica estrutural conhecida como cerâmica vermelha. A indústria de cerâmica vermelha, em seus aspectos atuais, está associada à idéia de degradação ambiental. Esta decorrente de impactos observados durante o seu processo produtivo, pois, os seus produtos dão-se com o uso de recursos naturais a argila â?¿ principal matéria-prima â?¿ e a lenha â?¿ principal insumo energético. Do ponto de visto econÃ'mico o insumo energético representa cerca de 35% do total dos gastos mensais para a produção dos produtos cerâmicos. Estudou-se a alternativa de utilizar o Capim Elefante como insumo energético para atender as condições de sustentabilidade econÃ'mica e ambiental. A utilização do Capim Elefante em indústria de cerâmica vermelha tem caracterÃsticas e dificuldades peculiares que foram analisadas com cuidados para oferecer a melhor alternativa do ponto de vista técnico, econÃ'mico e ambiental. O Capim Elefante tem sido identificado como uma espécie altamente eficiente para converter a energia solar incidente em energia quÃmica estocada nas plantas (ciclo fotossintético C4), resultando num potencial para produção de matéria seca. Sendo assim, visando proporcionar uma análise comparativa das diferentes etapas do processo produtivo de cerâmica estrutural, mas, que tenha como insumo energético o Capim Elefante, a metodologia de análise de ciclo de vida tem sido utilizada. O insumo energético avaliado possui um considerável potencial energético e pode ser produzido de forma sustentável. Com a análise de impactos, verificou-se que os poluentes gerados nas diferentes etapas do processo produtivo estão ligados, principalmente, a seis impactos ambientais, sendo eles a chuva ácida (kg SO2 eq.kg), toxidade humana (kg 1-4 DCB eq./kg), ozÃ'nio a baixa altitude (kg CFC â?¿ 11 eq./kg), eutroficação (kg PO43 eq /kg), aquecimento global (kg CO2 eq/ kg) e consumo de energia (GJ) / Abstract: In order to meet the sustainable development, energy plays a significant role. The majority of pollution in human activities is related to it. Renewable energies useâ?¿s desired to reduce or even eliminate the pollution without limiting the development of any industrial/business opportunity. In the present work the activity objective was defined as being the productive process of structural ceramic known as red ceramic. The industry of red ceramic, in its current aspects, it is associated to the idea of environmental degradation. This due to impacts observed during its productive process, because, its products are given with the use of natural resources the clay -main raw material -and the firewood -main energy input. Of the economic aspect the energy input represents about 35% of the total of the monthly expenses for the production of the ceramic products. It was studied the alternative of using the elephant grass as energy input to assist the conditions of economic and environmental sustainable. The use of the elephant grass in industry of red ceramic has characteristics and peculiar difficulties that were analyzed with cares to offer the best alternative of the technical, economic and environmental aspect. The elephant grass has been identified highly as a species efficient to convert the incident solar energy in chemical energy keeping in the plants (cycle photosynthesis C4), resulting in a potential for production of dry matter. Being like this, seeking to provide a comparative analysis of the different stages of the productive process of structural ceramic, but, that he/she has as energy input the elephant grass, the methodology of life cycle assessment has been used. The appraised energy input possesses a considerable energy potential and it can be produced in a maintainable way. With the analysis of impacts, it was verified that the pollution generated in the different stages of the productive process is tied up, mainly, to six environmental impacts, being them the acid rain (kg SO2 eq.kg), human toxic (kg 1-4 DCB eq. /kg), ozone the low altitude (kg CFC -11 eq. /kg), eutrofication (kg PO43 eq /kg), global heating (kg CO2 eq / kg) and consumption of energy (GJ) / Doutorado / Doutor em Planejamento de Sistemas Energéticos
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Beneath the sea ice : exploring elephant seal foraging strategy in Earth's extreme Antarctic polar environment / Sous la banquise Antarctique : écologie alimentaire des éléphants de mer des îles Kerguelen, influence des paramètres océanographiques et de glace de merLabrousse, Sara 09 December 2016 (has links)
Les mammifères marins de l'Océan Austral sont des éléments essentiels des écosystèmes marins antarctiques et des sentinelles de l’état des océans polaires. Comprendre comment les conditions océanographiques déterminent leurs habitats préférentiels est essentiel pour identifier de quelle façon et dans quelle région ces mammifères acquièrent les ressources nécessaires à leur déplacement, leur croissance, leur reproduction et donc leur survie. Les éléphants de mer du Sud (Mirounga leonina) se déplacent dans l’océan austral à l’échelle des bassins océaniques pour s’alimenter en plongeant en moyenne à 500 m et jusqu’à 2000 m de profondeur. En fonction de leur colonie d’origine, de leur sexe, et de leur âge, ils exploitent des régions radicalement différentes de l’océan austral, mettant ainsi en œuvre des stratégies alimentaires diversifiées. Les éléphants de mer de Kerguelen utilisent deux zones préférentiellement: la zone du Front Polaire ou la zone Antarctique couverte par la banquise. Dans cette thèse, les stratégies alimentaires des voyages post-mue Antarctiques de 46 mâles et femelles éléphants de mer de Kerguelen ont été étudiées. Une série temporelle de 11 années (2004-2014) de données de déplacement, de plongées et de données hydrologiques a été analysée pour déterminer le rôle des paramètres océanographiques et de glaces de mer impliqués dans l’acquisition des ressources alimentaires des éléphants de mer en Antarctique. L’influence de la variabilité spatio-temporelle et interannuelle de la glace de mer associée à la position des mâles et des femelles ainsi que le rôle des polynies côtières sur les stratégies alimentaires des mâles en hiver ont été examinés. / Understanding how physical properties of the environment underpin habitat selection of large marine vertebrates is crucial in identifying how and where animals acquire resources necessary for locomotion, growth and reproduction and ultimately their fitness. The Southern Ocean harbors one of the largest and most dynamic marine ecosystems on our planet which arises from the presence of two majors physical features, (i) the Antarctic Circumpolar Current and (ii) the seasonal sea ice cover region. In the Antarctic, marine predators are exposed to climate-induced shifts in atmospheric circulation and sea ice. However, because these shifts vary regionally, and because much remains to be understood about how individual animals use their environment, it has been difficult to make predictions on how animals may respond to climate variability. Southern elephant seals (Mirounga leonina) are a major consumer of Southern Ocean resources and use two main large scale foraging strategies, (i) feeding in the frontal zone of the Southern Ocean, or (ii) feeding in the seasonal sea ice region. In the present thesis I examined the winter post-moulting foraging strategies of 46 male and female Kerguelen southern elephant seals which utilized the second strategy. Using an eleven year time-series of tracking, diving, and seal-collected hydrographic data (from 2004-2014) I assessed their movements and foraging performance in relation to in situ hydrographic and sea ice conditions. The influence of both the spatio-temporal and inter-annual variability of sea ice around seal locations was investigated, and an investigation on the role of polynya for male elephant seal during winter conducted.
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Etude chimique et structurale de l'ivoire d'éléphant moderne et ancien / Chemical and structural study of modern and ancient elephant ivoryAlberic, Marie 15 September 2014 (has links)
L'ivoire d'éléphant est un matériau biologique composé de fibres de collagène (CF) à 30 % massique et de particules d'hydroxyapatite carbonatées et enrichies en Mg à 70 % massique (Mg-carb-HAP). Il présente une structure hiérarchique complexe de la macro à la nano-échelle. La relation entre le motif macroscopique de Schreger observé à la surface des sections transverses des défenses et la micro-morphologie de l'ivoire en 3D (réseau tubulaire et orientations secondaires des CF) a été établie. Les marqueurs chimiques (Ca, P, Mg, Sr) et structuraux (épaisseurs et organisation des particules de Mg-carb-HAP) témoins des processus de formation de l'ivoire ont été déterminés. La diagenèse précoce en milieu marin a ensuite été étudiée par une approche physico-chimique combinant les analyses MEB, PIXE/RBS-EBS et SAXS. Les mécanismes d'altération identifiés sont les adsorptions des ions du milieu extérieur (Cl, Sr, Fe, Cu) à la surface des défenses, les échanges entre les ions exogènes et endogènes de l'ivoire et l'augmentation de la cristallinité des Mg-carb-HAP. Bien qu'immergées dans le même environnement diagénétique, les trois défenses du site des Poulins présentent différents états d'altération. Un bon état de préservation macroscopique ne reflète pas forcément un bon état de conservation de la dentine à l'échelle moléculaire. Finalement, l'ancienne polychromie et la dorure d'origine des ivoires d'Arslan Tash (Syrie, 800 av. J.C.) ont été restituées par des analyses non-invasives par FX en plein champ et PIXE/RBS-EBS. Les couleurs identifiées sont: le bleu et le vert égyptiens (Cu), avec des teintes plus ou moins claires (Pb), le rouge et l'orange (Fe). / Elephant ivory is a biological material composed of collagen fibers (CF) at 30 wt. % and Mg-enriched carbonated hydroxyapatite particles at 70 wt. % (Mg-carb-HAP). It has a complex hierarchical structure from macro- down to nano-scale. The relationship between the macroscopic Schreger patterns observed on the surface of transverse sections of tuks and the 3D micro-morphology of ivory (tubular network and CF secondary orientations) has been established. Chemical (Ca, P, Mg, Sr) and structural markers (thickness and organization of particles Mg-carb-HAP) which control the formation of ivory have been determined. Early diagenesis in the marine environment was then studied by means of SEM, PIXE/RBS-EBS and SAXS analyses. Diagenetic mechanisms were identified, as ionic adsorptions from marine environment to the tusk surfaces, ionic substitutions between exogenous and endogenous ivory ions and increased crystallinity of Mg-carb-HAP. Different states of preservation were observed among three tusks coming from the same submarine archaeological site. Good macroscopic preservation states of the surface does not necessarily reflect good preservation states of the dentin at the molecular level. Finally, the former polychromy and gilding of ivories from Arslan Tash (Syria, 800 BC.) have been reconstructed by non-invasive FF-FX and PIXE/RBS-EBS analyses. Egyptian blue and green (Cu) with different shades (Pb), as well as red and orange (Fe) have been identified. The gilding technique consisted of applying a 2 µm thick gold leaf. Over time, these decorations altered ivory surfaces inducing, among others, the formation of Au nanoparticles derived from the weathering of the gold leafs.
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Semen characteristics of free-ranging African elephants (Loxodonta africana) and Southern white rhinoceros (Ceratotherium simum simum) using Computer-aided sperm analysis, Electron microscopy and Genomics as diagnostic toolsLuther, Ilse January 2016 (has links)
Philosophiae Doctor - PhD / The survival of free-ranging (in situ) African elephant and Southern white rhinoceros populations are currently being challenged on a daily basis in Africa. Reproductive health is considered a vital component of species conservation. Conservation of the last mega land mammals may ultimately require intervention by breeding management or combined with assisted reproductive technologies
(ART). There is a strong case for gathering baseline information, both physiological and biological, of any species, as opportunities arise. During this study a total number of 21 ejaculates collected over two seasons from 12 free-ranging
African elephant bulls were characterised, as well as 10 ejaculates collected from 10 free-ranging Southern white rhinoceros bulls from two populations. Ejaculates were collected from adult bulls by means of electroejaculation under anaesthesia. Routine semen analysis was combined with Computer-aided sperm analysis (CASA), Computer-aided sperm morphology analysis (CASMA), Transmission electron microscopy (TEM) and Genomics as diagnostic tools. Additionally, sperm
functionality within different media was investigated and sperm subpopulation classification according to the motion pattern displayed. The results presented is based on the evaluation and classification of ≈ 45 000 individual African elephant spermatozoa and ≈ 18 000 individual Southern white rhinoceros spermatozoa.
The average elephant ejaculate contained a total number of 47 x 10⁹ spermatozoa (volume of 56 ± 38mL x concentration of 818 ± 750 x 10⁶/mL) that recorded a total motility of 81 ± 29% of which 62 ± 26% were progressively motile. CASA recorded velocities for curvilinear velocity (VCL 241 ± 58μm/s), straight-line velocity (VSL 173 ± 181μm/s) and average path velocity (VAP 201 ± 54μm/s), and kinematics at straightness of track (STR 86 ± 85%), linearity of track (LIN 67 ± 16%), amplitude of lateral head displacement (ALH 4 ± 0.75μm) and beat cross frequency (BCF 21 ± 3Hz). Structural analysis revealed 68 ± 11% of the spermatozoa were viable (intact plasma membrane) and 77 ± 11% maintained acrosome integrity. Ejaculates contained 55 ± 14% morphologically normal spermatozoa, CASMA measured sperm head lengths at 6.83 ± 0.26μm and width 3.32 ± 0.18μm (total head area
of 20.17 ± 1.96μm²) of which 38.95 ± 0.92% is covered by an acrosomal cap. The average rhinoceros ejaculate contained a total number of 1.1 x 10⁹ spermatozoa (volume of 24 ± 24mL x concentration of 83 ± 96 x 10⁶/mL) that recorded a total motility at 82 ± 8% of which 28 ± 23% were progressively motile. CASA recorded velocities for VCL (85 ± 29μm/s), VSL (44 ± 25μm/s) and VAP (69 ± 30μm/s, and kinematics at STR (63 ± 14%), LIN (51 ± 16%), ALH (2 ± 0.16μm) and BCF
(16 ± 6Hz). Structural analysis revealed 73 ± 10% of the spermatozoa were viable (intact plasma membrane) and 76 ± 4% maintained acrosome integrity. Ejaculates contained 62 ± 14% morphologically normal spermatozoa, CASMA measured sperm head lengths at 5.5 ± 0.17μm and width 2.9 ± 0.19μm (total head area of 14.8 ± 1.43μm²) of which 36.3 ± 0.59% is covered by an acrosomal cap. Based on a Boolean argument and CASA data exploration it was possible to derive elephant and rhinoceros CASA cut-off criteria to sort between activated and hyperactivated motile spermatozoa. For the genomic component of this study, the CatSper1 (Loxodonta africana) gene was identified,sequenced and verified in a free-ranging (natural) African elephant population. Multivariate analysis(MVA) was applied to examine the associations between the semen and sperm parameters and the
traits they accounted for in this study. Our understanding of wildlife reproductive sciences can substantially progress as the analytical techniques applied and the combination thereof is expanded. This investigation presents a new set of comprehensive semen and sperm threshold values for future investigations.
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Contributions to the ecology of Maputaland, southern Africa, with emphasis on Sand ForestMatthews, Wayne Sidney 08 June 2007 (has links)
The principal hypothesis of this thesis was that the Maputaland Centre of Plant Endemism [MC] is characterised by plant communities that match a particular set of environmental variables, and their rich biodiversity with endemic and rare taxa reflecting the geomorphological history of the region. Data assembled supports the hypothesis. Vegetation studies highlighted two plant communities, endemic to the MC as being an important component of the region’s biodiversity, namely Sand Forest and Woody Grassland. A broad approach to the floristic classification of vegetation was adopted for information on the floristics patterns and diversity of the endemic/rare plants and plant communities of the MC. A hierarchical classification, description and ecological interpretation of the plant communities of the Tembe Elephant Park, Sileza Nature Reserve and surrounding areas are presented. Much of the vegetation distribution can be ascribed to the level of the water table, vegetation dynamics and historic evolution of the geomorphology of the region. The hypothesis is presented that Sand Forest may have allelopathic effects on its environment. Data of exploratory germination trials are presented to test this hypothesis. Sand Forest soil inhibits the emergence of seedlings, the inhibiting effect decreasing progressively from Sand Forest through grassland to woodland. Sand Forest was defined as a community, and its possible dynamics are described. Ideas were formulated (albeit largely hypothetical) on the likely origin of this vegetation type. It is proposed that ancient Dune Forest is the precursor of Sand Forest, but that Sand Forest has subsequently become a separate functioning plant community on its own. Sand Forest appears to be a relictual vegetation type of which the historical factors responsible for it’s original establishment and expansion are currently no longer present in the region. The use of woody species by elephant in different vegetation types in Tembe Elephant Park was investigated. A classification of species into utilization categories was produced which enabled assessment of the importance of different species to elephants, and also of the potential impact of elephants on different tree species. Management implications are highlighted. / Thesis (PhD (Botany))--University of Pretoria, 2007. / Plant Science / unrestricted
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Changes in diet resource use by elephants, Loxodonta Africana, due to changes in resource availability in the Addo National ParkDu Toit, Jana January 2015 (has links)
Animals are restricted in their diets by several factors, most notably the availability and quality of resources. Variation in resource availability causes herbivores to shift their diets seasonally and spatially. Elephants (Loxodonta africana), are known to have extensive impacts on plant communities, altering ecosystem functioning and causing a decline in biodiversity. In enclosed areas, these impacts are increased leading to a decline in resource availability and presumably resource quality. In the Addo Elephant National Park, the Main Camp section has a history of high elephant impacts and therefore reduced resource availability. Whereas, the recently added Colchester section has greater resource availability, due to the absence of elephants in this section since the fencing of the Park. This study investigated the changes in diet (diet breadth, preference and diet quality) of elephants due to an increase in resource availability. Three alternative hypotheses were contrasted: 1) elephants as generalist foragers, 2) elephants as optimal foragers, or 3) elephants learning foraging behaviour. Using microhistological analysis, the diets of elephants were described over five sampling periods (August 2010 – February 2014) in both sections. Forage availability was estimated using a modified line-intercept method, and was used to determine changes in preference by relating forage availability to use. In the Colchester section the diet breadth of elephants increased, and was coupled with a high initial variation between the diets of elephants, which decreased in subsequent sampling periods. This supported the elephants learning foraging behaviour hypothesis. However, there was no increase in diet preference by elephants in the Colchester section, which supported the elephants as generalist foragers hypothesis. There was also no difference in the diet quality of elephants in the Main Camp and Colchester sections, which did not support any of the three hypotheses. The elephants learning foraging behaviour hypothesis is proposed to be the link between the alternate two hypotheses, and given enough time, either of the two could be supported. The lack of difference in preference and diet quality between elephants in the Main Camp and Colchester sections is hypothesised to be due to the population level (not measured for individuals) at which these were measured. Microhistological analysis of faeces was used to describe the diet of elephants, which was compared to the diet described by DNA metabarcoding. Microhistological analysis is a traditional, favoured technique used in describing the diet of wild herbivores, whereas DNA metabarcoding is a relatively new and untested technique. These two techniques have not yet been compared in the diet of megaherbivores. Results indicated that microhistological analysis identified significantly more grass in the diet of elephants, than DNA metabarcoding did, which was expected as previous studies also found overestimation of grasses. Microhistological analysis identified more plant families in the diet of elephants, than DNA metabarcoding. Most of the differences between the two techniques can be attributed to the difference in taxonomic resolution, which was due to the lack of a complete reference collection for DNA metabarcoding. Although either of the two techniques can be used to describe the diet of elephants, the most reliable results would be obtained when using both techniques. The findings of this study suggest that due to the high initial variation between the diets of elephants, with an increase in resource availability, the impacts will also initially be highly varied. This suggests that identifying plant species to monitor elephants impacts initially will be difficult. However, important plant species, or those known to be vulnerable to elephants impacts should be carefully monitored initially and monitoring should not only occur annually, but also seasonally.
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Detection and Tracking of Elephants using Seismic Direction of Arrival EstimatesWestlund, Albin, Goderik, Daniel January 2023 (has links)
As human settlement expands into the natural habitats of wild animals, the conflict between humans and wildlife increases. The human-elephant conflict is one that causes a tremendous amount of damage, often to poor villages close to the savannah. In this master's thesis, a system is developed, that is intended to detect, localise and track elephants from seismic vibrations generated from footsteps. The system consists of multiple devices, with three geophones, and a microprocessor each. To detect the footsteps, two different methods are evaluated. One that analyses features consistion of the normalised standard deviation, frequency peak, spectral centroid and low compared to high frequency content of a signal. These features of the signal are then compared to those of an elephant footstep. The other one compares the frequency content of the seismic wave from a footstep to an computed average of known elephant footsteps. The signal feature method performed the best with an accuracy of 89 %, and detecting 54 % of the footsteps. The detected footstep is sent to a backend where further calculations are done. With one device, estimations of the direction of arrival (DOA) angle can be made. This is done using a delay and sum algorithm. By using a Kalman filter on the DOA estimates, the bearing to the elephant can be tracked over time. From the detected elephant footsteps it has been shown that it is possible to estimate the direction of an elephant with quite high performance and by applying a Kalman filter to track the elephant, it has been shown that the filter gives better and more reasonable estimates. With two devices, a location can be estimated with triangulation and also an elephant's position can be tracked. With triangulation, where the easting position estimated to some extent, but the northing position did not give good results. By using these localisations estimates in a Kalman filter the elephant could be tracked in most of the cases with high enough performance and especially when there weren't too many high northing estimates. By using separate DOA estimations in an extended Kalman filter the easting position could be tracked fairly well, while the northing updates had some strange behaviours, most probably because of implementation error. / Project Ngulia
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