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81.
José Lino Costa Isabel Domingos Carlos A. Assis Pedro R. Almeida Francisco Moreira Eric Feunteun Maria José Costa 《Environmental Biology of Fishes》2008,81(4):421-434
A total of 1,816 eels were sampled in 1988, from seven sampling areas. Four areas were located in brackish water and the remaining
three were located in freshwater reaches of the Tagus river basin. Eels were more abundant in the middle estuary and decreased
both in the upstream and in the downstream directions, with a predominance of males in higher density areas. Smaller individuals
preferred more peripheral areas, such as margins and upper reaches in the brackish water zone, and the tributaries of the
freshwater habitats. It was assumed that this distribution pattern resulted from three main factors: (i) the dominance of
larger specimens; (ii) the need to avoid predators and; (iii) the search for better trophic conditions. The condition of the
individuals generally decreased toward the upper reaches, apparently due to a corresponding decrease in feeding intensity.
The presence of the Belver dam in the main river, 158 km upstream from the sea, seemed to impose major alterations to the
described patterns. The concentration of specimens below this impassable obstacle yielded a reduction in the proportion of
females and a decrease in the condition and survival of the eels, contributing to a reduction in the spawning success of this
population. Suggestions to diminish the effects of the dam, and to preserve the fishery are also presented. 相似文献
82.
Renan Janke Bosque Jente Ottenburghs Cecília Rodrigues Vieira Fabrícius Maia Chaves Bicalho Domingos 《Evolution; international journal of organic evolution》2020,74(11):2541-2543
Mimicry can directly affect the evolutionary history of models, mimics, and signal receivers. Mimics often use multimodal signaling to deceive receivers. Jamie et al. showed that brood parasitic birds display multimodal signaling of mimetic traits triggered by sexual and filial imprinting on host species. These resulting adaptations can interact with premating isolation barriers to strengthen reproductive isolation and potentially drive sympatric speciation. 相似文献
83.
A novel toxin (TdK1) was purified from the venom of the scorpion Tityus discrepans, sequenced and functionally characterized. It contains 37 amino acid residues and blocks reversible the shakerB K+ channel expressed in SF9 cells with a Kd in the order of 280 nM. The proposed systematic nomenclature for this peptide is alpha-KTx4.3. 相似文献
84.
Abstract— Seven N-(5′-phosphopyridoxyl) amino acids, reduced analogs of the glutamate-pyridoxal phosphate Schiff base, were synthesized and purified. All of them inhibited mouse brain glutamate decarboxylase activity. The four most potent inhibitors were the aminooxyacetate, GABA, cysteinesul-finate and glutamate derivatives, and the effect of these compounds was studied kinetically. The inhibition produced was in all cases mixed function with respect to glutamate and competitive with respect to pyridoxal phosphate. The inhibition kinetics were non-linear. These results are interpreted in terms of an ordered binding of pyridoxal phosphate and glutamate to the enzyme. Furthermore, they are consistent with previous findings suggesting the existence of two kinds of glutamate decarboxylase activity differing in their dependence on free pyridoxal phosphate. 相似文献
85.
Rodrigo R. Domingues Domingos Garrone-Neto Alexandre W. S. Hilsdorf Otto B. F. Gadig 《Journal of fish biology》2019,94(3):512-516
In this study we tested the use of mucus from five species of Neotropical marine batoid elasmobranchs to extract genomic DNA for barcoding and phylogenetic analysis. The DNA from all individuals sampled was successfully amplified and sequenced for molecular barcode, allowing 99–100% accuracy to the species level. This method proved to provide reliable and good-quality DNA for barcoding and phylogenetic analysis of Neotropical elasmobranchs, through rapid handling and with low disturbance to animals. 相似文献
86.
Varaschin MS Hirsch C Wouters F Nakagaki KY Guimarães AM Santos DS Bezerra PS Costa RC Peconick AP Langohr IM 《The Korean journal of parasitology》2012,50(1):63-67
Congenital Neospora caninum infection was diagnosed in two Saanen goat kids from two distinct herds with a history of abortion and weak newborn goat kids in the Southern region of the State of Minas Gerais, Brazil. The first kid was weak at birth, had difficulty to rise and was unable to nurse. Gross lesions of porencephaly and hydrocephalus ex vacuo were seen. Multifocal necrosis, gliosis and non-supurative encephalitis were observed in the brain. Several parasitic cysts with a thick wall that reacted strongly only with polyclonal antiserum to Neospora caninum were seen in the cerebral cortex, brain stem and cerebellum. The second kid was born from a Neospora caninum seropositive mother that aborted in the last pregnancy. It was born without clinical signs. The diagnosis of neosporosis was based on antibody titer of 1:800 to N. caninum by indirect fluorescence antibody test obtained from blood collected before the goat kid ingested the colostrum and Neospora caninum DNA was detected by polymerase chain reaction and sequenced from placenta. This is the first report of neosporosis in goats in the southeast region of Brazil. 相似文献
87.
Detoni CB de Oliveira DM Santo IE Pedro AS El-Bacha R da Silva Velozo E Ferreira D Sarmento B de Magalhães Cabral-Albuquerque EC 《Journal of liposome research》2012,22(1):1-7
Zanthoxylum tinguassuiba essential oil (ZtEO) contains α-bisabolol, a known antiglioma sesquiterpene, among other potentially active substances. Medical applications of this essential oil require advances in the design of distinctive carriers due to its low water solubility and easy degradation by heat, light, and oxygen. The aim of this work was to evaluate enhancement in oxidative stability and the ability to reduce glioblastoma cell viability of ZtEO loaded into liposomes. Multi- and unilamellar vesicles were prepared to carry ZtEO. By using thermal analysis, it was observed that thermal-oxidative stability of the liposomal ZtEO was enhanced, when compared to its free form. Liposomal ZtEO also presented significant apoptotic-inducing activity for glioma cells. These results show that liposomal systems carrying ZtEO may be a potential alternative for gliobastoma treatment. 相似文献
88.
Cavasini CE De Mattos LC Alves RT Couto AA Calvosa VS Domingos CR Castilho L Rossit AR Machado RL 《Human biology; an international record of research》2006,78(2):215-219
We compared the serological phenotypic frequencies of ABO, MNSs, and Duffy in 417 blood donors and 309 malaria patients from four Brazilian Amazon areas. Our results suggest no correlation between ABO phenotype and malaria infection in all areas studied. We observed significant correlation between the S +s +, S +s -, and S -s + phenotypes and malaria infection in three areas. Some of the Duffy phenotypes showed significant correlation between donors and malaria patients in different areas. These data are an additional contribution to the establishment of differential host susceptibility to malaria. 相似文献
89.
Vinícius R. Campos Paula A. Abreu Helena C. Castro Carlos R. Rodrigues Alessandro K. Jordo Vitor F. Ferreira Maria C.B.V. de Souza Fernanda da C. Santos Laura A. Moura Thaisa S. Domingos Carla Carvalho Eldio F. Sanchez Andr L. Fuly Anna C. Cunha 《Bioorganic & medicinal chemistry》2009,17(21):7429-7434
The current treatment used against envenomation by Lachesis muta venom still presents several side effects. This paper describes the synthesis, pharmacological and theoretical evaluations of new 1-arylsulfonylamino-5-methyl-1H-[1,2,3]-triazole-4-carboxylic acid ethyl esters (8a–f) tested against the hemolytic profile of the L. muta snake venom. Their structures were elucidated by one- and two-dimensional NMR techniques (1H, APT, HETCOR 1JCH and nJCH, n = 2, 3) and high-resolution electrospray ionization mass spectrometry. The series of triazole derivatives significantly neutralized the hemolysis induced by L. muta crude venom presenting a dose-dependent inhibitory profile (IC50 = 30−83 μM) with 1-(4′-chlorophenylsulfonylamino)-5-methyl-1H-[1,2,3]-triazole-4-carboxylic acid ethyl ester (8e) being the most potent compound. The theoretical evaluation revealed the correlation of the antiophidian profile with the coefficient distribution and density map of the Highest Occupied Molecular Orbitals (HOMO) of these molecules. The elucidation of this new series may help on designing new and more efficient antiophidian molecules. 相似文献
90.
Gerardo Corzo Cedric Bernard Herlinda Clement Elba Villegas Frank Bosmans Jan Tytgat Lourival D. Possani Herve Darbon Alejandro Alagón 《Biochimica et Biophysica Acta - Proteins and Proteomics》2009,1794(8):1190-1196
Soluble venom and purified fractions of the theraposid spider Brachypelma albiceps were screened for insecticidal peptides based on toxicity to crickets. Two insecticidal peptides, named Ba1 and Ba2, were obtained after the soluble venom was separated by high performance liquid chromatography and cation exchange chromatography. The two insecticidal peptides contain 39 amino acid residues and three disulfide bonds, and based on their amino acid sequence, they are highly identical to the insecticidal peptides from the theraposid spiders Aphonopelma sp. from the USA and Haplopelma huwenum from China indicating a relationship among these genera. Although Ba1 and Ba2 were not able to modify currents in insect and vertebrate cloned voltage-gated sodium ion channels, they have noteworthy insecticidal activities compared to classical arachnid insecticidal toxins indicating that they might target unknown receptors in insect species. The most abundant insecticidal peptide Ba2 was submitted to NMR spectroscopy to determine its 3-D structure; a remarkable characteristic of Ba2 is a cluster of basic residues, which might be important for receptor recognition. 相似文献