Spelling suggestions: "subject:"snail"" "subject:"inail""
71 |
Estudo matemático do mecanismo de regulação da esquistossomíase / Mathematical study of the mechanism of regulation of schistosomiasisYang, Hyun Mo 16 October 1990 (has links)
Neste trabalho foram estudados dois mecanismos de regulação de esquistossomíase: a nível de hospedeiro intermediário (Modelo de May) e a nível de hospedeiro definitivo (Modelo de Imunidade Concomitante por período de incubação). Estudou-se como ambos os modelos comportam se quando da introdução de um modelo de regulação para a população do hospedeiro intermediário. Verificou-se que o modelo de regulação por imunidade concomitante é muito mais robusto, pois além de ajustar melhor a curva de prevalência fornece uma região de estabilidade para os parâmetros epidemiológicos muito maior. / In this work two mechanisms for the regulation of the schistosomiasis were studied. In one model the regulation takes place at the intermediate host (May Model) and in the other model the regulation takes place at the definitive host (concomitant Immunity) . In both models the regulation of the intermediate host population was also included. It was found that regulation in the definitive host is much more robust than the regulation on the intermediate host allowing for a much greater range of the epidemiological parameters. Also the model of regulation on the definitive host allows for a very good fit of the prevalence curve.
|
72 |
Controle de infecções intramamárias no gado leiteiro usando as propriedades antibacterianas e cicatrizantes do muco de escargots Achatina sp no pré e pós dipping / Control of intramammary infections in dairy cattle using antibacterial and healing properties of the mucus of snails Achatina sp in pre and post dippingYokoya, Eugênio 21 May 2010 (has links)
O controle de mastite consiste em um conjunto de medidas de manejo e prevenção da doença em um rebanho, pois estudos realizados em todo estado de São Paulo estimaram um prejuízo de 17% da produção por propriedade devido à mastite considerando perdas como os gastos com tratamentos; descarte de leite; queda na produção; além de perdas por resíduos de antibióticos. O trabalho mostra que a população microbiana da mucosa dos tetos não varia conforme a sua posição no úbere do animal e a identificação dos microorganismos predominantes foram como sendo de Staphylococcus aureus, Micrococcus luteus, Klebsiella pneumoniae e Acinetobacter junii. O objetivo deste trabalho foi determinar a eficácia do muco de escargot nos tetos de vacas leiteiras utilizando-o como \"pré e pós dipping\" e o comparado com a aplicação de solução de iodo, visando à prevenção ou a redução da incidência de infecções intramamárias. O muco de escargot possui uma propriedade antibacteriana bastante efetiva, conhecida como Achacin. Sua ação bactericida ocorre principalmente na fase de crescimento da bactéria agindo como agente quimioterápico. O muco de escargot mostrou ser igualmente eficiente no controle da população de microorganismo presente na superfície dos tetos, quando comparados ao uso da solução de iodo, além de que o seu efeito sobre a pele e mucosa dos tetos foi de deixá-los mais hidratados e com melhor elasticidade evitando rachaduras e focos de infecção, quando comparado ao agente mineral, podendo ser até mesmo um produto alternativo no controle e prevenção de mastite em vacas leiteiras. / The control of mastitis is a set of measures for management and prevention of disease in a herd, because studies from every state of Sao Paulo have estimated a loss of 17% in a property considering losses due to mastitis as spending on treatments; discarded milk, drop in production, and losses due to antibiotic residues. The study shows that the microbial population of the mucosa of the teats doesnt vary according to their position in the animal\'s udder and identification of microorganisms were predominant as Staphylococcus aureus, Micrococcus luteus, Klebsiella pneumoniae and Acinetobacter junii. The objective of this study was to determine the effectiveness of snail mucus teats of dairy cows using it as a \"pre and post dipping\" and compared with the application of iodine solution, aiming at preventing or reducing the incidence of mammary infections. The mucus of snail has a very effective antibacterial property, known as Achacin. Its bactericidal action occurs mainly in the growth of bacteria by acting as a chemotherapeutic agent. The mucus of snail proved to be equally effective in controlling the population of microorganisms present on the surface of the teats, compared to the use of iodine solution, and that its effect on the skin and mucous membrane of the teats was leaving them more hydrated and with improved elasticity avoiding cracks and foci of infection, when compared to mineral agent, which may even be an alternative product in the control and prevention of mastitis in dairy cows.
|
73 |
Field application of environmental DNA techniques to detect early stages of invasion by the destructive New Zealand mud snailWoodell, James D. 01 May 2019 (has links)
Nonnative species that cause damage to ecosystems to which they are introduced are considered in-vasive. Restoration of the original ecosystem after an invasive population has established is expensive and difficult but more likely to succeed when invasions are discovered early. Containment efforts to prevent the spread of known invasions also benefit from earlier knowledge of invaded sites. Environ-mental DNA (eDNA) techniques are emerging as a tool that can identify invasive species at a distinctly earlier time point than traditional methods of detection. I collected water samples from eight sites not known to be invaded by the freshwater New Zealand mud snail (NZMS). After filtering these samples to collect eDNA, I used a species-specific probe with qPCR to identify NZMS eDNA. I found evidence for NZMS invasion at five of the eight sites, with later physical confirmation of mud snails at one of these sites. This study is the first example of successful application of eDNA to detect new invasions of the freshwater New Zealand mud snail, setting the stage for further monitoring of at-risk sites to de-tect and control new invasions of this destructive snail.
|
74 |
Factors conditioning the distribution of fresh water pulmonates, <em>Biomphalaria </em>spp., <em>Bulinus </em>spp., and <em>Lymnea </em>spp., in Babati District, Tanzania.Lydig, Anna January 2009 (has links)
<p>The aim of this essay was to investigate if different variables affected the distribution of fresh water pulmonate in Babati District, Tanzania. Can the absence of intermediate host be explained by basic vegetation evaluation, pH, conductivity and temperature? Or can it be explained by other factors as animals and vegetation in the surrounding? The study was carried out in Babati District, in Lake Babati, Kiongozi/Farahani River and the irrigation schemes in Matufa and Gichameda from the 23td of February until 7th of March, 2009. The species found during the survey were <em>Biomphalaria, Bulinus, </em>and <em>Lymnea. </em>Only <em>Biomphalaria pfeifferi </em>were present in the genus <em>Biomphalaria</em>. In <em>Bulinus </em>spp.<em>, B. globosus, B. forskalii, </em>and <em>B. africanus </em>were present. <em>Lymnea spp</em>. was represented by <em>L. natalensis</em>. Statistical tests were carried out with logistic models. The results of the statistical analysis revealed different significant results for the different snail species present. <em>L. natalensis </em>showed a significantly positive effect of the water temperature and was distributed in water temperatures ranging from 20.9°C to 24.3°C, which is in the lower range in this study. <em>Biomphalaria pfeifferi </em>and <em>Bulinus spp</em>. were significantly affected to an increase in conductivity. L. natalensis did show a significant effect of the type of bottom in the water body, and found muddy bottoms more suitable. Animal activity (livestock) did show a significant effect on the distribution of <em>L. natalensis </em>which found habitats without animals more suitable. Both <em>B. pfeifferi </em>and <em>L. natalensis </em>were significantly affected by vegetation in the surrounding and found habitats with grass, shrubs and trees more favourable before cultivated areas and forests. The statistical analysis made on the data collected in Babati District showed that temperature, conductivity, bottom in water body and vegetation in the surrounding, in general, significantly affected the fresh water pulmonate. Several variables as pH, water flow, canopy cover, vegetation in the water, however, were not significantly affecting the distribution of the snails. Further investigations of interactive effects of variables, however, are necessary to prevent high infection rates of trematodes infecting the pulmonate present in Babati District, Tanzania.</p>
|
75 |
Factors conditioning the distribution of fresh water pulmonates, Biomphalaria spp., Bulinus spp., and Lymnea spp., in Babati District, Tanzania.Lydig, Anna January 2009 (has links)
The aim of this essay was to investigate if different variables affected the distribution of fresh water pulmonate in Babati District, Tanzania. Can the absence of intermediate host be explained by basic vegetation evaluation, pH, conductivity and temperature? Or can it be explained by other factors as animals and vegetation in the surrounding? The study was carried out in Babati District, in Lake Babati, Kiongozi/Farahani River and the irrigation schemes in Matufa and Gichameda from the 23td of February until 7th of March, 2009. The species found during the survey were Biomphalaria, Bulinus, and Lymnea. Only Biomphalaria pfeifferi were present in the genus Biomphalaria. In Bulinus spp., B. globosus, B. forskalii, and B. africanus were present. Lymnea spp. was represented by L. natalensis. Statistical tests were carried out with logistic models. The results of the statistical analysis revealed different significant results for the different snail species present. L. natalensis showed a significantly positive effect of the water temperature and was distributed in water temperatures ranging from 20.9°C to 24.3°C, which is in the lower range in this study. Biomphalaria pfeifferi and Bulinus spp. were significantly affected to an increase in conductivity. L. natalensis did show a significant effect of the type of bottom in the water body, and found muddy bottoms more suitable. Animal activity (livestock) did show a significant effect on the distribution of L. natalensis which found habitats without animals more suitable. Both B. pfeifferi and L. natalensis were significantly affected by vegetation in the surrounding and found habitats with grass, shrubs and trees more favourable before cultivated areas and forests. The statistical analysis made on the data collected in Babati District showed that temperature, conductivity, bottom in water body and vegetation in the surrounding, in general, significantly affected the fresh water pulmonate. Several variables as pH, water flow, canopy cover, vegetation in the water, however, were not significantly affecting the distribution of the snails. Further investigations of interactive effects of variables, however, are necessary to prevent high infection rates of trematodes infecting the pulmonate present in Babati District, Tanzania.
|
76 |
Population Studies on Austropeplea Ollula (Gould), the Snail Intermediate Host of Dermatitis-producing Avian SchistosomesISHIGURO, TORAO, MAKIYA, KIYOSHI 03 1900 (has links)
No description available.
|
77 |
Functional Role of Dead-Box P68 RNA Helicase in Gene ExpressionLin, Chunru 31 July 2006 (has links)
How tumor cells migrate and metastasize from primary sites requires four major steps: invasion, intravasation, extravasation and proliferation from micrometastases to malignant tumor. The initiation of tumor cell invasion requires Epithelial-Mesenchymal Transition (EMT), by which tumor cells lose cell-cell interactions and gain the ability of migration. The gene expression profile during the EMT process has been extensively investigated to study the initiation of EMT. In our studies, we indicated that tyrosine phosphorylation of human p68 RNA helicase positively associated with the malignant status of tumor tissue or cells. Studying of this relationship revealed that p68 RNA helicase played a critical role in EMT progression by repression of E-cadherin as an epithelial marker and upregulation of Vimentin as a mesenchymal marker. Insight into the mechanism of how p68 RNA helicase represses E-cadherin expression indicated that p68 RNA helicase initiated EMT by transcriptional upregulation of Snail. Human p68 RNA helicase has been documented as an RNA-dependent ATPase. The protein is an essential factor in the pre-mRNA splicing procedure. Some examples show that p68 RNA helicase functions as a transcriptional coactivator in ATPase dependent or independent manner. Here we indicated that p68 RNA helicase unwound protein complexes to modulate protein-protein interactions by using protein-dependent ATPase activity. The phosphorylated p68 RNA helicase displaced HDAC1 from the chromatin remodeling MBD3:Mi2/NuRD complex at the Snail promoter. Thus, our data demonstrated an example of protein-dependent ATPase which modulates protein-protein interactions within the chromatin remodeling machine.
|
78 |
Molecular and Cellular Complexity of Glioma : Highlights on the Double-Edged-Sword of Infiltration Versus Proliferation and the Involvement of T CellsÇağlayan, Demet January 2012 (has links)
Glioblastoma multiforme (GBM), the most common and malignant brain tumor, is characterized by high molecular and cellular heterogeneity within and among tumors. Parameters such as invasive growth, infiltration of immune cells and endothelial proliferation contribute in a systemic manner to maintain the malignancy. Studies in this thesis show that the expression of Sox2 is correlated with Sox21 in human gliomas. We demonstrate that an upregulation of Sox21 induces loss of proliferation, apoptosis and differentiation in glioma cells in vitro and in vivo and seems to correlate with decreased Sox2 expression. Induced expression of Sox21 in vivo significantly reduces the tumor size and increase the survival extensively, suggesting that Sox21 can act as a tumor suppressor Our studies indicate that the balance of Sox21-Sox2 in glioma cells is decisive of either a proliferative or a non-proliferative state. Several TGFß family members have an important role in glioma development. TGFß promotes proliferation and tumorigenicity whereas BMPs mostly inhibit proliferation. We demonstrate that BMP7 can induce the transcription factor Snail in glioma cells and that this reduces the tumorigenicity with a concomitant increase in invasiveness. Thus, we have identified a mechanism to the double-edged sword of proliferation versus invasiveness in GBM, the latter contributing to relapse in patients. Experimental gliomas were induced with the Sleeping Beauty (SB) model in mice with different immunological status of their T cells. The tumors that developed were either GBMs or highly diffuse in their growth, reminiscent of gliomatosis cerebri (GC). GC is a highly uncommon form of glioma characterized by extensive infiltrative growth in large parts of the brain. It is an orphan disease and today there is practically a total lack of relevant experimental models. The SB system would constitute a novel experimental model to study the mechanisms behind the development of diffusely growing tumors like GC. The presence or absence of T cells did not affect tumor development. The work in this thesis demonstrates that the proliferative and the invasive capacities of glioma cells can be dissociated and that the SB model constitutes an excellent model to study the highly proliferative cells in GBMs versus the highly invasive cells in diffuse tumors like .GC.
|
79 |
A Retrospective Analysis of the Potential Environmental Stressors Responsible for the Decline of the Natural Populations of the Florida Apple Snail (Pomacea paludosa) in the A.R.M. Loxahatchee National Wildlife RefugeLadd, Shannon 01 November 2010 (has links)
The purpose of this thesis is to determine the factors that contributed to
the decline of Florida apple snail ( Pomacea paludosa) populations in the A.R.M.
Loxahatchee National Wildlife Refuge with the goal of devising management
recommendations to the Refuge regarding population management strategies.
The factors examined that could have potentially contributed to population
decline include the use of copper-based herbicides, insecticide application, the
occurrence of drought, the use of other herbicides, the occurrence of fire, and
non-avian predation. Annual Narrative documents produced by Refuge
managers and staff members, dated from 1951 to 2007, were used to collect
historical data for these factors. The quality of data reporting within the Annual
Narratives was also examined. To support data on droughts documented in the
Annual Narratives, surface water and rainfall data were obtained and analyzed.
The methodology includes the use of conceptual ecological models and historical
ecology to determine whether or not the factors examined produced an
ecological effect capable of affecting the Refuge population of apple snails.
Evidence from the Annual Narratives suggests that the use of copper-based
herbicides, the occurrence of drought, and predation by alligators were
responsible for the decline of the apple snail on the Refuge. A lack of consistently
reported data regarding apple snail densities makes it difficult to determine the
degree to which each factor had an effect on the apple snails or to determine if
any spatio-temporal relationship existed between the Florida apple snail and
Everglade snail kite ( Rostrhamus sociabilis plumbeus) based on copper-based
herbicide use. The overall quality of the Annual Narratives improved throughout
the study period and eventually focused heavily on investigative studies. Several
management recommendations were suggested to improve Florida apple snail
populations on the Refuge. First, in order to monitor the health and trends of the
apple snail population, a monitoring network needs to be established with results
maintained in a geodatabase. Both apple snail density and egg cluster counts
need to be made following an established sampling method. Second, in an
attempt to sustain higher apple snail densities, stocking of the interior should be
attempted. Finall, in the event that adjacent farmlands are to be restored, soil
samples need to be analyzed to determine if concentrations are high enough that
desorption of copper from the flooded agricultural soils could pose a serious
threat to the Refuge by reintroducing toxic levels of copper.
|
80 |
From Out of the ShellVice President Research, Office of the 12 1900 (has links)
A new era of pain management could be on the horizon. How Terry Snutch turned snail venom into a multi-million dollar painkiller.
|
Page generated in 0.0976 seconds