392 research outputs found
La creciente parodización del formato policial clásico en las anti-ilustradas novelas detectivescas del escritor suizo protestante Friedrich Dürrenmatt.
Este artĂculo parte de la hipĂłtesis que el escritor suizo protestante Friedrich DĂĽrrenmatt parodia, en forma creciente, el gĂ©nero policial clásico. Ante todo, la figura del detective, sĂmbolo de la fe ilustrada y luego positivista en la inevitable victoria de la razĂłn, sufre una creciente desconstrucciĂłn dado que su mĂ©todo, basado precisamente en la inteligencia humana, fracasa ante el predominio del azar, que irrumpe en la vida de los seres humanos en forma parecida que la gracia divina
Snowshoe Hare use of Silviculturally Altered Conifer Forests in The Greater Yellowstone Ecosystem
Information about snowshoe hare habitat use in key Canada lynx recovery areas, such as the Greater Yellowstone Ecosystem, is critical for the conservation of lynx. Although research conclusions differ in regard to the types and ages of forests preferred by snowshoe hares, restrictions on silvicultural practice have been implemented by forest managers to protect snowshoe hares in this area. However, some research suggests that regenerating lodgepole pine stands associated with silvicultural treatments benefit snowshoe hares. We evaluated three indices of snowshoe hare use within a timber management area in southwest Montana, inside the Greater Yellowstone Ecosystem (1999–2012) to assess the relative use of forest types. We analyzed: 1) 11 years of data collected from 280 pellet plots using linear mixed models and AICc model selection, 2) 13 years of track counts from 2,202 km of roadway travel using Chi-squared goodness-of-fit tests of proportional segment lengths and the associated cover types, and 3) 76 nights over one winter of live-trapping using a hare/night index. Overall, we observed the greatest use within the youngest two classes of regenerating lodgepole pine stands that were associated with clear cutting and pre-commercial thinning. These results suggest snowshoe hares prefer silviculturally influenced 30–60 years old lodgepole pine forests
Functional Characterization of the Epidermal Cholinergic System In Vitro
The aim of this study was to analyze the influence of cholinergic and anticholinergic drugs on epidermal physiology using organotypic cocultures (OTCs). Blocking of all acetylcholine receptors (AChRs) by combined treatment with mecamylamine and atropine or treatment with strychnine (blocking α9nAChR) for 7–14 days resulted in a complete inhibition of epidermal differentiation and proliferation. Blockage of nicotinic (n)AChR with mecamylamine led to a less pronounced delay in epidermal differentiation and proliferation than blockage of muscarinic (m)AChR with atropine, evidenced by reduced epithelial thickness and expression of terminal differentiation markers like cytokeratin 2e or filaggrin. In OTCs treated with atropine, mecamylamine, or strychnine, we could demonstrate intracellular lipid accumulation in the lower epidermal layers, indicating a severely disturbed epidermal barrier. In addition, we observed prominent acantholysis in the basal and lower suprabasal layers in mecamylamine-, atropine-, and strychnine-treated cultures, accompanied by a decreased expression of cell adhesion proteins. This globally reduced cell adhesion led to cell death via intrinsic activation of apoptosis. In contrast, stimulation of nAChR and mAChR with cholinergic drugs resulted in a significantly thickened epithelium, accompanied by an improved epithelial maturation. In summary, we show that epidermal AChR are crucially involved in the regulation of epidermal homeostasis
A novel α-conotoxin, PeIA, cloned from Conus pergrandis, discriminates between Rat α9α10 and α7 nicotinic cholinergic receptors
The α9 and α10 nicotinic cholinergic subunits assemble to form the receptor believed to mediate synaptic transmission between efferent olivocochlear fibers and hair cells of the cochlea, one of the few examples of postsynaptic function for a non-muscle nicotinic acetylcholine receptor (nAChR). However, it has been suggested that the expression profile of α9 and α10 overlaps with that of α7 in the cochlea and in sites such as dorsal root ganglion neurons, peripheral blood lymphocytes, developing thymocytes, and skin. We now report the cloning, total synthesis, and characterization of a novel toxin α-conotoxin PeIA that discriminates between α9α10 and α7 nAChRs. This is the first toxin to be identified from Conus pergrandis, a species found in deep waters of the Western Pacific. α-Conotoxin PeIA displayed a 260-fold higher selectivity for α-bungarotoxin-sensitive α9α10 nAChRs compared with α-bungarotoxin-sensitive α7 receptors. The IC50 of the toxin was 6.9 ± 0.5 nM and 4.4 ± 0.5 nM for recombinant α9α10 and wild-type hair cell nAChRs, respectively. α-Conotoxin PeIA bears high resemblance to α-conotoxins MII and GIC isolated from Conus magus and Conus geographus, respectively. However, neither α-conotoxin MII nor α-conotoxin GIC at concentrations of 10 ÎĽM blocked acetylcholine responses elicited in Xenopus oocytes injected with the α9 and α10 subunits. Among neuronal non-α-bungarotoxin- sensitive receptors, α-conotoxin PeIA was also active at α3β2 receptors and chimeric α6/α3β2β3 receptors. α-Conotoxin PeIA represents a novel probe to differentiate responses mediated either through α9α10 or α7 nAChRs in those tissues where both receptors are expressed.Fil: McIntosh, J. Michael. University of Utah; Estados UnidosFil: Plazas, Paola Viviana. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Investigaciones en IngenierĂa GenĂ©tica y BiologĂa Molecular "Dr. HĂ©ctor N. Torres"; ArgentinaFil: Watkins, Maren. University of Utah; Estados UnidosFil: Gomez Casati, Maria Eugenia. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Investigaciones en IngenierĂa GenĂ©tica y BiologĂa Molecular "Dr. HĂ©ctor N. Torres"; ArgentinaFil: Olivera, Baldomero M.. University of Utah; Estados UnidosFil: Elgoyhen, Ana Belen. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Investigaciones en IngenierĂa GenĂ©tica y BiologĂa Molecular "Dr. HĂ©ctor N. Torres"; Argentin
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