115 resultados para Merluccius, Nasello, feeding, stomaci, morphological, molecular

em Repositório Institucional UNESP - Universidade Estadual Paulista "Julio de Mesquita Filho"


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Broad nosed caiman are ectotherm sauropsids that naturally experience long fasting intervals. We have studied the postprandial responses by measuring oxygen consumption using respirometry, the size changes of the duodenum, the distal small intestine, and the liver, using repeated non-invasive ultrasonography, and by investigating structural changes on the level of tissues and cells by using light- and electron microscopy. The caimans showed the same rapid and reversible changes of organ size and identical histological features, down to the ultrastructure level, as previously described for other ectothermic sauropsids. We found a configuration change of the mucosa epithelium from pseudostratified during fasting to single layered during digestion, in association with hypertrophy of enterocytes by loading them with lipid droplets. Similar patterns were also found for the hepatocytes of the liver. By placing the results of our study in comparative relationship and by utilizing the phylogenetic bracket of crocodiles, birds and squamates, we suggest that the observed features are plesiomorphic characters of sauropsids. By extending the comparison to anurans, we suggest that morphological and physiological adjustments to feeding and fasting described here may have been a character of early tetrapods. In conclusion, we suggest that the ability to tolerate long fasting intervals and then swallow a single large meal as described for many sit-an-wait foraging sauropsids is a functional feature that was already present in ancestral tetrapods.

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Thin solid films of bis benzimidazo perylene (AzoPTCD) were fabricated using physical vapor deposition (PVD) technique. Thermal stability and integrity of the AzoPTCD PVD films during the fabrication (similar to 400 degrees C at 10(-6) Torr) were monitored by Raman scattering. Complementary thermogravimetric results showed that thermal degradation of AzoPTCD occurs at 675 degrees C. The growth of the PVD films was established through UV-vis absorption spectroscopy, and the surface morphology was surveyed by atomic force microscopy (AFM) as a function of the mass thickness. The AzoPTCD molecular organization in these PVD films was determined using the selection rules of infrared absorption spectroscopy (transmission and reflection-absorption modes). Despite the molecular packing, X-ray diffraction revealed that the PVD films are amorphous. Theoretical calculations (density functional theory, B3LYP) were used to assign the vibrational modes in the infrared and Raman spectra. Metallic nanostructures, able to sustain localized surface plasmons (LSP) were used to achieve surface-enhanced resonance Raman scattering (SERRS) and surface-enhanced fluorescence (SEF).

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Maytenus s. l. (including Gymnosporia) is a morphologically diverse genus of about 300 species that is widely distributed in the tropics and subtropics of both the Old and New Worlds. Its delimitation has been extensively debated and despite the segregation of Gymnosporia, Maytenus s. s. remains a heterogeneous, polyphyletic group. To delimit natural segregate genera we increased taxon sampling and generated sequences from two nuclear gene regions (ITS and 26S rDNA) and two plastid loci (matK and trnL-F) to analyze together with morphological characters. Both Moya and Tricerma were found to be nested within the New World Maytenus and are recognized as synonyms of Maytenus s. s.. In contrast, the three New World species of Gymnosporia are recognized as a new genus that is closely related to Gyminda. Haydenia is erected for these three species: H. gentryi, H. haberiana, and H. urbaniana. One or more previously proposed or novel genera are required to accommodate the systematically difficult African Maytenus. Putterlickia, and most likely Gloveria, are nested within Gymnosporia and should be synonymized with that genus. New binomials are required for four Chinese and one Rapan species of Gymnosporia that have been previously treated only as Maytenus: Gymnosporia austroyunnanensis, G. confertiflora, G. dongfangensis, G. guangxiensis, and G. pertinax. Austral-Pacific Maytenus are transferred to Denhamia, requiring eight new binomials: Denhamia bilocularis, D. cunninghamii, D. cupularis, D. disperma, D. fasciculiflora, D. ferdinandii, D. fournieri, and D. silvestris. Existing intrageneric classifications of Gymnosporia and Maytenus s. s. were not supported in their entirety. Gymnosporia is inferred to have had an African origin followed by dispersals to Madagascar, southeast Asia and the Austral-Pacific.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Brazilian isolates of Colletotrichum spp. from citrus orchards affected by postbloom fruit drop were examined for colony colour, mycelial growth, benomyl-resistance, pathogenicity, and genetic variability by random amplified polymorphic DNA (RAPD) analysis. All isolates were obtained from flowers and persistent calyxes from different citrus hosts from São Paulo, Brazil. DNA polymorphisms detected after amplification with random 10-mer primers were used to classify the isolates into two groups. Group I isolates grew rapidly on potato-dextrose agar (PDA) and were sensitive to benomyl, and group II isolates grew slowly on PDA and were benomyl-resistant. Colletotrichum acutatum was analyzed by RAPD and had high genetic similarity with group II isolates of Colletotrichum from citrus. Probably, the group I is C, gloeosporioides and group II is C. acutatum.

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Risk assessments suggest that intermediate and long-term exposure to triazine herbicides and its metabolites through water can cause severe damage to human health. The objective of this study was to investigate the possible effects of atrazine on Wistar rats submitted to subacute treatment. For this purpose, the activity of catalase and alanine aminotransferase was quantified, and the effect of the herbicide on cell membranes was examined based on the measurement of lipid peroxidation and consequent formation of malondialdehyde and on the mRNA expression of antioxidant enzymes (Mn-superoxide dismutase [SOD] and GSTM1) and connexins. In addition, we evaluated histopathological alterations in the liver, cellular expression of SOD and glutathione (GST), activation of heat shock proteins (HSPs) by immunohistochemistry, and the induction of apoptosis. The genotoxic potential of the herbicide was investigated by the micronucleus test in bone marrow smears. Adult male Wistar rats were treated with an aqueous solution of atrazine at a concentration of 400 mg/kg/day, by gavage, for 14 consecutive days. Control groups were also included. The results showed an increase of catalase levels and maintenance of the expression of antioxidant enzymes (SOD and GST). In addition, lipid peroxidation, hepatic tissue degeneration, activation of HSP90, increased levels of connexin mRNA, and genotoxicity were observed. In conclusion, atrazine induced early hepatic oxidative stress that triggered defense mechanisms to maintain the morphophysiological integrity of the liver. Further studies are needed to better understand the effects of this herbicide on human health. (C) 2011 Elsevier B.V. All rights reserved.