950 resultados para spider-hunting wasp


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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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This booklet is not a complete set of hunting laws. It contains basic information needed during the hunting and trapping seasons.

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Background: In the field of Plastic Reconstructive Surgery the development of new innovative matrices for skin repair is in urgent need. The ideal biomaterial should promote attachment, proliferation and growth of cells. Additionally, it should degrade in an appropriate time period without releasing harmful substances, but not exert a pathological immune response. Spider dragline silk from Nephila spp meets these demands to a large extent. Methodology/Principal Findings: Native spider dragline silk, harvested directly out of Nephila spp spiders, was woven on steel frames. Constructs were sterilized and seeded with fibroblasts. After two weeks of cultivating single fibroblasts, keratinocytes were added to generate a bilayered skin model, consisting of dermis and epidermis equivalents. For the next three weeks, constructs in co-culture were lifted on an originally designed setup for air/liquid interface cultivation. After the culturing period, constructs were embedded in paraffin with an especially developed program for spidersilk to avoid supercontraction. Paraffin cross-sections were stained in Haematoxylin & Eosin (H&E) for microscopic analyses. Conclusion/Significance: Native spider dragline silk woven on steel frames provides a suitable matrix for 3 dimensional skin cell culturing. Both fibroblasts and keratinocytes cell lines adhere to the spider silk fibres and proliferate. Guided by the spider silk fibres, they sprout into the meshes and reach confluence in at most one week. A well-balanced, bilayered cocultivation in two continuously separated strata can be achieved by serum reduction, changing the medium conditions and the cultivation period at the air/liquid interphase. Therefore spider silk appears to be a promising biomaterial for the enhancement of skin regeneration.

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Background: Several materials have been used for tissue engineering purposes, since the ideal matrix depends on the desired tissue. Silk biomaterials have come to focus due to their great mechanical properties. As untreated silkworm silk has been found to be quite immunogenic, an alternative could be spider silk. Not only does it own unique mechanical properties, its biocompatibility has been shown already in vivo. In our study, we used native spider dragline silk which is known as the strongest fibre in nature. Methodology/Principal Findings: Steel frames were originally designed and manufactured and woven with spider silk, harvesting dragline silk directly out of the animal. After sterilization, scaffolds were seeded with fibroblasts to analyse cell proliferation and adhesion. Analysis of cell morphology and actin filament alignment clearly revealed adherence. Proliferation was measured by cell count as well as determination of relative fluorescence each after 1, 2, 3, and 5 days. Cell counts for native spider silk were also compared with those for trypsin-digested spider silk. Spider silk specimens displayed less proliferation than collagen-and fibronectin-coated cover slips, enzymatic treatment reduced adhesion and proliferation rates tendentially though not significantly. Nevertheless, proliferation could be proven with high significance (p<0.01). Conclusion/Significance: Native spider silk does not require any modification to its application as a biomaterial that can rival any artificial material in terms of cell growth promoting properties. We could show adhesion mechanics on intracellular level. Additionally, proliferation kinetics were higher than in enzymatically digested controls, indicating that spider silk does not require modification. Recent findings concerning reduction of cell proliferation after exposure could not be met. As biotechnological production of the hierarchical composition of native spider silk fibres is still a challenge, our study has a pioneer role in researching cellular mechanics on native spider silk fibres.

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Colorectal cancer (CRC) is the second most common cancer in Europe, with the second highest mortality rate. Although prognosis is improving, survival rates remain poor for those presenting with the most advanced stages of the disease. There is therefore a need for improved early diagnosis and thus a greater understanding of the early stages of the development of colorectal tumours is desirable. Additionally, as most deaths in colorectal cancer are due to advanced metastatic disease, it is of great interest to explore any potential mechanisms by which metastatic disease can be inhibited. N-WASP is a ubiquitously expressed protein with multiple intracellular roles including actin regulation and maintaining stability of epithelial cell-cell junctions. Through its role as an actin regulator, it has been implicated in the processes of invasion and metastasis of multiple cancer types. Its role in the development and progression of colorectal cancer however has not been fully explored. This thesis will present a series of in vitro and in vivo studies that were carried out with the aim of answering the following questions: • Does N-Wasp have a role in normal intestinal homeostasis? • Does N-Wasp knockout affect the development of tumours in a mouse model of intestinal tumourigenesis? • Does N-Wasp knockout affect the invasive properties of intestinal cancer in vitro? • Does N-WASP correlate with prognosis or other indicators in human colorectal cancer TMAs? Findings from the in vivo experiments, using an inducible, gut-specific knockout model, have uncovered potential roles for N-Wasp in regulating differentiation and migration of intestinal epithelial cells. Although it had no effect in short term models of intestinal hyperproliferation, N-Wasp knockout increased tumour burden and decreased survival in an established in vivo model of intestinal tumourigenesis, in which there is heterozygous loss of Apc (Apcfl/+). No effect was seen on tumour development or survival when additional N-WASP knockout was introduced into a more rapid model, with heterozygous loss of Apc and mutation of Kras (Apcfl/+ KrasG12D/+). N-WASP expression in human colorectal cancer was assessed using immunohistochemical staining of two tissue microarrays. Low levels of N-WASP expression were found to be associated with presence of MMR deficiency. There was no statistically significant difference in overall or cancer specific survival based on N-WASP expression. Collectively, the data presented here suggest a previously unreported role for N-WASP in regulation of intestinal epithelial differentiation and indicate that it may act as a tumour suppressor against development of benign precursor lesions of colorectal cancer. Further research is warranted to delineate the mechanisms underlying these processes.

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In the present study, the effects of Polybia paulista venom (PPV) on renal and vascular tissues were investigated. Isolated kidneys perfused with PPV (1 and 3 mu g/mL) had increased perfusion pressure, renal vascular resistance, urinary flow, and glomerular filtration rate; and reduced sodium tubular transport. Histological evaluation demonstrated deposits of proteins in Bowman's space and tubular lumen, and focal areas of necrosis. The venom promoted a cytotoxic effect on Madin-Darby canine kidney (MDCK) cells. A significant increase in lactic dehydrogenase levels was observed in response to venom exposure. In isolated mesenteric vascular beds, pressure and vascular resistance augmented in a dose-dependent manner. PPV increased the contractility of aortic rings maintained under basal tension. This contractile response was inhibited when preparations were maintained in Ca2+-free medium. Likewise, verapamil, a voltage-gated calcium channel blocker, also inhibited the contractile response. In this study, phentolamine, a blocker of a-adrenergic receptor blocker, significantly reduced the contractile effect of PPV in the aortic ring. In conclusion, PPV produced nephrotoxicity, which suggests a direct effect on necrotic cellular death in renal tubule cells. The vascular contractile effect of PPV appears to involve calcium influx through voltage-gated calcium channels via adrenergic regulation.

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The prevalence and infestation intensities of Octolasmis lowei in the bronchial chambers of Libinia spinosa were evaluated according to the host's sex, size, and moult condition. Epibionts were classified as cyprid larvae, non-ovigerous or ovigerous according to their developmental stage. A median intensity of infestation of 21 epibionts/host was found (range = 1-644; Q(3) = 81). Epibiont prevalence values (88%) were higher on ovigerous female hosts than on males (55%) or on non-ovigerous females (31%). Intensity of infestation was positively correlated with host size in both sexes for non-ovigerous and ovigerous epibionts. No preference between host sex by cyprid larvae was observed, nor any correlation between cyprid abundance and host size. Cyprid larvae abundance was positively correlated with settled epibionts on both host sexes. The duration of the intermoult phase was the main factor linked to the establishment of sessile epibionts. These observations are important in relation to crabs that have a terminal moult, because these animals cannot eliminate their epibionts in future moults, thus increasing the importance of density-dependent mechanisms on epibiont establishment; in that way, prevalence of infestation alone can underestimate the real impact of infestation on the host's life cycle.

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Mastoparans are tetradecapeptides found to be the major component of vespid venoms. A mastoparan toxin isolated from the venom of Anterhynchium flavomarginatum micado has been crystallized and X-ray diffraction data collected to 2.7 Angstrom resolution using a synchrotron-radiation source. Crystals were determined to belong to the space group P6(2)22 (P6(4)22). This is the first mastoparan to be crystallized and will provide further insights into the conformational significance of mastoparan toxins with respect to their potency and activity in G-protein regulation.

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Mastoparans are tetradecapeptides found to be the major component of vespid venoms. These peptides present a wide spectrum of biological activities, such as mast cell degranulation, hemolytic activity and also reveals antimicrobial activity. A mastoparan toxin isolated from the venom of Anterhynchium flavomarginatum micado has been crystallized. At room temperature these crystals diffracted to 2.8 Angstrom resolution. However, upon cooling to cryogenic temperature around 85 K, the original resolution limit could be improved to 2.0 Angstrom. Crystals were determined to belong to the space group P3(1) (P3(2)). This is the first mastoparan to be crystallized and it will provide further insights in the conformational significance of mastoparan toxins, with respect to their potency and activity in G protein regulation. (C) 3001 Elsevier B.V. B.V. All rights reserved.

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Humans’ perceived relationship to nature and non-human lifeforms is fundamental for sustainable development; different framings of nature – as commodity, as threat, as sacred etc. – imply different responses to future challenges. The body of research on nature repre-sentations in various symbolic contexts is growing, but the ways in which nature is framed by people in the everyday has received scant attention. This paper aims to contribute to our understanding of the framing of nature by studying how wild-boar hunting is depicted on YouTube. The qualitative frame analysis identified three interrelated frames depicting hunting as battle, as consumption, and as privilege, all of which constitute and are constituted by the underlying notion of human as superior to nature. It is suggested that these hegemonic nature frames suppress more constructive ways of framing the human-nature relationship, but also that the identification of such potential counter-hegemonic frames enables their discursive manifestation.

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The 2012 Public Alligator Hunting Season marked the fifth general alligator hunting season after a closure of nearly 40 years. This year’s public hunt, utilizing a random computer drawing, was open to all applicants, including nonresidents, and was conducted on public and private lands (not enrolled in the Private Lands Program) from the Midlands to the coast. A total of 321 applications for the WMA Alligator Hunt were received, 89.1% from residents, the remainder from eleven other states. The 2012 season began at noon on September 13th and ended at noon on October 10th. This booklet also shows the season results of the hunt and recommendations for the next year's hunt.

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The 2013 Public Alligator Hunting Season marked the sixth general alligator hunting season after a closure of nearly 40 years. This year’s public hunt, utilizing a random computer drawing, was open to all applicants, including nonresidents, and was conducted on public and private lands (not enrolled in the Private Lands Program) from the Midlands to the coast. A total of 222 applications for the WMA Alligator Hunt were received, 89.1% from residents, the remainder from eleven other states. The 2013 season began at noon on September 14th and ended at noon on October 12th. This booklet also shows the season results of the hunt and recommendations for the next year's hunt.

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This booklet was developed to provide basic information regarding the alligator hunting season and what hunters will need in order to familiarize themselves with taking alligators. It includes common hunting techniques, safety tips, how to harvest an alligator, requirements for processing an alligator, and how to care for an alligator hide.