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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.
1

Aspects of the reproduction of male and female African penguins (Spheniscus demersus) with special reference to sperm biology and cryopreservation

Mafunda, Patrick Siyambulela January 2018 (has links)
Philosophiae Doctor - PhD / In the marine environment, penguins have been described as curators and serve a critical role in ecological balance. The African penguin (Spheniscus demersus) has undergone a rapid population decline, mainly due to disturbances in their natural habitat. The African penguin was up-listed from vulnerable to endangered on the IUCN Red List for Threatened Species in 2010 and thus urgent conservation action is required. Integral to long-term conservation action of any species is a basic knowledge of its reproductive biology, which is currently lacking for African penguins. The main aim of this investigation was to evaluate techniques for the collection of semen in African penguin and to determine sperm quality in order to cryopreserve sperm for in vitro fertilization (IVF) purposes of captive and wild populations. Semen was collected once a week during two breeding seasons from two captive African penguins. Ejaculates (n=51) were obtained over two breeding seasons (Jan-Feb and Jun-Oct) and evaluated for semen volume, sperm concentration, sperm vitality, sperm motility and sperm morphology. In addition twelve (six females and six males, n=4 were breeding pairs) captive African penguins were monitored for hormone (estradiol, testosterone, progesterone) levels prior to and after the egg-laying period.
2

Molecular Characterization of Hybridization Between Magellanic (Spheniscus magellanicus) and Humboldt (Spheniscus humboldti) Penguins in the Wild.

Hibbets, Eric Matthew 07 August 2019 (has links)
No description available.
3

Avaliação epidemiológica da aspergilose em pinguins-de-Magalhães no Centro de Recuperação de Animais Marinhos FURG / Epidemiological survey of aspergillosis in Magellanic penguins at the Centro de Recuperação de Animais Marinhos FURG

SILVA FILHO, Rodolfo Pinho da 03 February 2012 (has links)
Made available in DSpace on 2014-08-20T14:37:49Z (GMT). No. of bitstreams: 1 dissertacao_rodolfo_silva.pdf: 3168091 bytes, checksum: ce68f91004a1b87e7c1c6a31886c8d10 (MD5) Previous issue date: 2012-02-03 / The Centro de Recuperação de Animais Marinhos (CRAM-FURG) is a rehabilitation center that works essentially with debilitated Magellanic penguins (Spheniscus magellanicus), aiming to rehabilitate and release them to their natural habitat. However, several of the received penguins develop aspergillosis, an opportunistic fungal disease frequently responsible for the death of captive birds, often in association with the stress experienced by these animals in captivity. This study aimed to examine a six-year period for cases of aspergillosis in Magellanic penguins undergoing rehabilitation at CRAMFURG. For that purpose, a retrospective cohort study was conducted using the institution s records of Magellanic penguins received from January 2004 to December 2009. Animals were classified in two groups: the case group included animals that died from aspergillosis, the control group included animals that survived and were released or those that died from conditions unassociated with aspergillosis. Variables examined as potential risk factors were age group, gender, oil fouling, precedence, prophylactic administration of itraconazole, time in captivity until death or release, body mass, and hematological parameters such as hematocrit and total plasmatic proteins. During this period, the institution received 366 Magellanic penguins, of which 39 were excluded from the analyses due to the insufficiency of data on their cause of death, thus 327 animals were studied. During the studied period, 66 penguins died of aspergillosis. Aspergillus fumigatus was the most frequent etiological agent (98.5%). Relative mortality by aspergillosis was 48.5% during the examined period, and the density of incidence was 7.3 lethal aspergillosis cases per 100 penguins-month. Approximately 75% of the aspergillosis cases occurred in animals received through transfers from other rehabilitation centers, and this was considered a significant risk factor for the disease, with a relative risk of greater than 3.0. Significant differences were also observed between the case and control groups in regards to their time in captivity until death, their hematocrit and total plasmatic proteins upon admission to the center, and their body mass change during the period in captivity. The findings demonstrate the negative impacts of aspergillosis on the rehabilitation of Magellanic penguins, with a high density of incidence and important mortality of these animals. / O Centro de Recuperação de Animais Marinhos (CRAM-FURG) trabalha essencialmente com pinguins-de-Magalhães (Spheniscus magellanicus) debilitados, com a intenção de reabilita-los e devolvê-los ao seu habitat natural. No entanto, muitos exemplares recebidos acabam desenvolvendo aspergilose, uma doença fúngica oportunista frequentemente responsável pela morte de aves em cativeiro, associada ao estresse sofrido por estes animais. Neste sentido, este trabalho objetivou realizar um levantamento epidemiológico de seis anos da aspergilose em pinguins-de-Magalhães em reabilitação no CRAM-FURG. Para isso, foi realizado um estudo de coorte retrospectivo a partir de informações coletadas do banco de dados do CRAM-FURG referentes aos pinguins recebidos no período de janeiro de 2004 a dezembro de 2009. Os animais foram classificados em dois grupos, sendo o grupo caso referente a pinguins que morreram por aspergilose, e o grupo controle aquele composto por animais que foram liberados ou morreram por outras causas. As variáveis analisadas quanto a fator de risco foram idade, sexo, petrolização, procedência, uso de itraconazol profilático, tempo de cativeiro, peso corpóreo e parâmetros sanguíneos como hematócrito e proteínas plasmáticas totais. Durante esse período o Centro recebeu 366 pinguins de Magalhães, dos quais 39 foram excluídos do estudo por não apresentarem dados disponíveis no banco de dados sobre sua causa mortis, resultando num total de 327 animais. Durante o período estudado, 66 pinguins morreram por aspergilose, sendo Aspergillus fumigatus o principal agente etiológico encontrado, com 98,5% dos casos. A mortalidade proporcional por aspergilose foi de 48,5% no período de seis anos de estudo, e a densidade de incidência encontrada foi de 7,3 casos de aspergilose/100 pinguinsmês. Aproximadamente 75% dos casos de aspergilose ocorreram em animais procedentes de outros Centros de reabilitação, sendo este considerado um fator de risco para a doença, com risco relativo maior que 3,0. Também foram encontradas diferenças significativas entre os grupos caso e controle em relação ao tempo de cativeiro, valores de hematócrito e proteínas plasmáticas totais na chegada ao Centro, e ganho de peso durante o período de cativeiro. Os achados deste estudo demonstram a interferência negativa da aspergilose na reabilitação de pinguins-de-Magalhães, com alta densidade de incidência, e responsável por importante mortalidade destes animais.
4

Monitoramento sorológico para diagnóstico precoce da aspergilose em pinguins em cativeiro / Monitoramento sorológico para diagnostic precoce da aspergilose em pinguins em cativeiro

Cabana, Ângela Leitzke 28 February 2013 (has links)
Made available in DSpace on 2014-08-20T14:37:52Z (GMT). No. of bitstreams: 1 dissertacao_angela_cabana.pdf: 1514484 bytes, checksum: a7b8213a229cc70d85faecf587014b8a (MD5) Previous issue date: 2013-02-28 / Aspergillosis is a leading cause of death in captive penguins. Though being a known problem for decades, most reported cases are still only confirmed in post-mortem examinations, requiring further studies on methods for in vivo diagnosis of the disease. This study aimed to evaluate the efficacy of detection of anti-Aspergillus fumigatus antibodies through the performance by serological monitoring with agar gel double radial immunodiffusion (AGID) for in vivo diagnosis of aspergillosis in captive penguins. The study was performed including Magellanic penguins in a rehabilitation program at Center for Recovery of Marine Animals (CRAM/FURG) in the period from 2009 to 2011. We included 134 Magellanic penguins (Spheniscus magellanicus) in rehabilitation at CRAM, which were monitored by AGID weekly until its final destination (death or release) totaling 660 studied serum samples. The serological monitoring was performed in order to detect anti-Aspergillus fumigatus antibodies using commercial antibodies and antigen. All animals were clinically monitored and post-mortem examinations were performed on penguins that died during the study period. A total of 28% (37/134) penguin died, 89.2% (33/37) of aspergillosis, 11% (4/37) of other causes and 97 were released. From the 33 animals with proven aspergillosis, 21 had anti-A. fumigatus antibodies by AGID, being the average interval between death and the positive AGID result of 16.4 days. Twelve seronegative animals eventually died of aspergillosis. The rates of sensitivity and specificity were 63.6% and 95%, respectively, and positive and negative predictive values were 80.7% and 88.9% respectively. These data demonstrate that serological monitoring for the detection of antibodies by AGID may be a useful and important tool for the diagnosis of aspergillosis in penguins. As our study with AGID in penguins is pioneer, more studies are required concerning the prognosis in cases of aspergillosis in penguins whose therapeutic intervention is based on diagnosis by AGID, considering that the average period between the positive result of this test and the death of the animal was less than one month. Key-words: Sphenisciformes. Captivity / A aspergilose é uma das principais causas de morte de pinguins em cativeiro. Embora este seja um problema conhecido há décadas, a maioria dos casos relatados são ainda confirmados em exames post-mortem, sendo necessários mais estudos sobre os métodos de diagnóstico in vivo da doença. Assim, este trabalho objetivou avaliar a eficácia da detecção de anticorpos anti-Aspergillus fumigatus através do desempenho do monitoramento sorológico por imunodifusão radial dupla em gel de ágar (IDGA) para o diagnóstico in vivo da aspergilose em pinguins em cativeiro. O estudo foi realizado incluindo pinguins-de-Magalhães em reabilitação no Centro de Recuperação de Animais Marinhos (CRAM/FURG) no período de 2009 a 2011.. Foram incluídos 134 pingüins de Magalhães (Spheniscus magellanicus) em reabilitação no Centro de Recuperação de Animais Marinhos (CRAM / FURG), que foram monitorados por IDGA semanalmente até seu destino final (morte ou de liberação), totalizando 660 amostras de soro estudadas. O monitoramento sorológico foi realizado para detecção de anticorpos anti-Aspergillus fumigatus utilizando antígeno e anticorpos comerciais. Todos os animais foram acompanhados clinicamente e exames post-mortem foram realizados em pinguins que vieram a óbito durante o período do estudo. Um total de 28% (37/134) dos pinguins veio a óbito, 89,2% (33/37) de aspergilose, 11% (4/37) de outras causas e 97 foram libertados. A partir dos 33 animais com aspergilose comprovada, 21 apresentaram anticorpos anti- A. fumigatus por IDGA, sendo o intervalo médio entre a morte e as IDGA positivas 16,4 dias. Doze animais com sorologia negativa vieram a óbito por aspergilose. As taxas de sensibilidade e especificidade foram de 63,6% e 95%, respectivamente, e os valores preditivo positivo e negativo foram 80,7% e 88,9%, respectivamente. Estes dados demonstram que o acompanhamento serológico para a detecção de anticorpos por IDGA pode ser uma ferramenta útil e importante para o diagnóstico de aspergilose em pinguins. Como nosso estudo com IDGA em pinguins é pioneiro, maiores estudos são necessários acerca do prognóstico dos casos de aspergilose em pinguins cuja intervenção terapêutica se baseie no diagnóstico por IDGA, considerando que o período médio entre o resultado positivo deste teste e o óbito do animal foi de menos de um mês.

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