Non-minimal kinetic coupling and Chaplygin gas cosmology

In the frame of the scalar field model with non minimal kinetic coupling to gravity, we study the cosmological solutions of the Chaplygin gas model of dark energy. By appropriately restricting the potential, we found the scalar field, the potential and coupling giving rise to the Chaplygin gas solution. Extensions to the generalized and modified Chaplygin gas have been made.Comment: 18 pages, 2 figures. To appear in EPJ

Single-step purification of crotapotin and crotactine from Crotalus durissus terrificus venom using preparative isoelectric focusing

We describe the isolation of crotoxin, a presynaptic B-neurotoxin, as well as its subunits B (crotactine) and A (crotapotin) from lyophilized Crotalus durissus terrificus venom by a single-step preparative isoelectric focusing procedure. From 98 mg of dried venom protein 20.1 mg of crotactine and 13.1 mg of crotapotin were recovered in the first step of focalization and 4.2 mg in a second run. These values correspond to 35.7% of the total venom protein applied. Crotactine separated in the 9.3-7.0 pH range (tubes 1-6) and crotapotin in the 1.8-2.8 pH range (tubes 15-19) and both were homogeneous by SDS-PAGE and N-terminal amino acid analysis. Crotactine, a 12-kDa protein, presented hemolytic and phospholipase A2 activity. Thus, using isoelectric focusing we simultaneously purified both toxins in high yields. This method can be used as an alternative for the purification and characterization of proteins from other snake venoms under conditions in which biological activity is retaine

Bioquímica plasmática de cascavéis (Caudisona durissa LINNAEUS, 1758) em cativeiro Blood biochemical parameters from captivity rattlesnake (Caudisona durissa LINNAEUS, 1758)

Acidentes com seres humanos envolvendo a espécie Caudisona durissa possuem a mais alta taxa de letalidade dentre os viperídeos brasileiros. Ressalta-se então a importância para a saúde pública da criação dessa espécie em cativeiro para produção de soro antiofídico. No entanto, essa atividade ainda hoje encontra alguns desafios como a instalação de doenças no plantel, evidenciando a importância de estudos sobre a fisiologia de serpentes. Dessa forma, foram realizadas análises de bioquímica plasmática em 53 serpentes da espécie Caudisona durissa, mantidas em cativeiro. Foram utilizadas amostras de plasma com heparina e as dosagens bioquímicas realizadas em aparelho automatizado (Ciba Corning - Express Plus®). Os resultados e seus respectivos desvios-padrões foram: uréia -1,32mg dL-1 (&plusmn;1,1); ácido úrico - 2,08mg dL-1 (&plusmn;1,4); creatinina - 0,52mg dL-1 (&plusmn;0,2); proteína total - 3,7g dL-1 (&plusmn;0,7); albumina - 1,62g dL-1 (&plusmn;0,4); globulinas - 2,08g dL-1 (&plusmn;0,5); cálcio - 15,25mg dL-1 (&plusmn;2,8); fósforo - 4,61mg dL-1 (&plusmn;1,9); colesterol - 171,58mg dL-1 (&plusmn;52,7); triglicerídeos - 19,29mg dL-1 (&plusmn;14,3); fosfatase alcalina - 31,04U L-1 (&plusmn;12,4); aspartato aminotransferase (AST) - 22,25U L-1 (&plusmn;11,4); alanina aminotransferase (ALT) - 7,11U L-1 (&plusmn;5,4) e Amilase - 1385,23U L-1 (&plusmn;568,7). Foram calculados os seguintes índices: relação uréia/creatinina - 2,5 e relação cálcio/fósforo - 3,3. O conjunto de resultados das análises bioquímicas do sangue das cascavéis em cativeiro pode servir como referência para apoio diagnóstico na espécie estudada e para outros trabalhos com o mesmo caráter de observação.<br>Human accidents involving rattlesnake Caudisona durissa have the highest fatality rate among the Brazilian Viperidae family. Breeding this specie in captivity in order to produce antivenoms is very important to public health. Nevertheless, there are some challenges that this activity must face, like the onset of diseases on the breeding stock, justifying the importance of studying these snakes' physiology. Blood biochemical analysis of 53 Caudisona durissa was performed using plasma samples in an automated equipment (Ciba Corning - Express Plus®). Mean values and its respective Standard deviations are: blood urea nitrogen (BUN) -1.32mg dL-1 (&plusmn;1.1); uric acid - 2.08mg dL-1 (&plusmn;1.4); creatinine - 0.52mg dL-1 (&plusmn;0.2); total protein - 3.7g dL-1 (&plusmn;0.7); albumin - 1.62g dL-1 (&plusmn;0.4); globulins - 2.08g dL-1 (&plusmn;0.5); calcium - 15.25mg dL-1 (&plusmn;2.8); phosphorus - 4.61mg dL-1 (&plusmn;1.9); cholesterol - 171.58mg dL-1 (&plusmn;52.7); triglycerides - 19.29mg dL-1 (&plusmn;14.3); alkaline phosfatase - 31.04U L-1 (&plusmn;12.4); aspartate aminotransferase (AST) - 22.25U L-1 (&plusmn;11.4); alanin aminotransferase (ALT) 7.11U L-1 (&plusmn;5.4); amylases - 1385.23U L-1 (&plusmn;568.7). The following indexes were calculated: BUN/creatinine ratio - 2.5 and calcium/phosphorus ratio -3.3. Rattlesnake blood biochemical results above could be used as reference in clinical evaluation for captivity C. durissa

Contribuição à biologia de serpentes da Bahia, Brasil: I. vivíparas Contribution to reproductive biology of snakes in Bahia, Brazil: I. viviparous

<abstract language="eng">Great part of lhe avaiable data about snakes reprodution refers to species coming from subtropical and temperate regions. In Brazil, the data is rather rare and can be found in various works where information is restricted. Results from studies developed with five viviparous snakes - Crotalus durissus cascavella (Wagler, 1824). Bothrops erythromelas(Amaral, 1923), B. leucurus (Wagler, 1824), Helicops leopardinus (Schlegel, 1873) and Thamnodynastes strigilis (Thiinberg, 1787) - which come from the Northeast of Brazil (Bahia) are described. Data about pregnancy and birth, number, sex ratio, length and weight of neonates is given and discussed