Optic chiasm in the species of order Clupeiformes, family Clupeidae: Optic chiasm of Spratelloides gracilis shows an opposite laterality to that of Etrumeus teres

In most teleost fishes, the optic nerves decussate completely as they project to the mesencephalic region. Examination of the decussation pattern of 25 species from 11 different orders in Pisces revealed that each species shows a specific chiasmic type. In 11 species out of the 25, laterality of the chiasmic pattern was not determined; in half of the individuals examined, the left optic nerve ran dorsally to the right optic nerve, while in the other half, the right optic nerve was dorsal. In eight other species the optic nerves from both eyes branched into several bundles at the chiasmic point, and intercalated to form a complicated decussation pattern. In the present study we report our findings that Spratelloides gracilis, of the order Clupeiformes, family Clupeidae, shows a particular laterality of decussation: the left optic nerve ran dorsally to the right (n = 200/202). In contrast, Etrumeus teres, of the same order and family, had a strong preference of the opposite (complementary) chiasmic pattern to that of S. gracilis (n = 59/59), revealing that these two species display opposite left–right optic chiasm patterning. As far as we investigated, other species of Clupeiformes have not shown left–right preference in the decussation pattern. We conclude that the opposite laterality of the optic chiasms of these two closely related species, S. gracilis and E. teres, enables investigation of species-specific laterality in fishes of symmetric shapes

Singlet oxygen quenching and radical scavenging capacities of structurally-related flavonoids present in Zuccagnia punctata Cav.

The singlet oxygen ((1)O(2)) quenching and free radical (DPPH(center dot), ABTS(center dot+) and O(2)(center dot-)) scavenging ability of three structurally-related flavonoids (7-hydroxyflavanone HF, 2',4'-dihydroxychalcone DHC and 3,7- dihydroxyflavone DHF) present in the Argentinean native shrub Zuccagnia punctata Cav. were studied in solution by combining electrochemical and kinetic measurements, mass spectroscopy, end-point antioxidant assays and computational calculations. the results showed that the antioxidant properties of these flavonoids depend on several factors, such as their electron- and hydrogen atom donor capacity, the ionization degree of the more acidic group, solvatation effects and electrostatic interactions with the oxidant species. the theoretical calculations for both the gas and solution phases at the B3LYP level of theory for the Osanger reaction field model agreed with the experimental findings, thus supporting the characterization of the antioxidant mechanism of the Z. punctata flavonoids.CONICETANPCyTCICyT-UNSECIUNTFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Univ Nacl Santiago del Estero, CONICET, INQUINOA, Fac Agron & Agroind, RA-4200 Santiago Del Estero, ArgentinaUniv Nacl Tucuman, Fac Bioquim Quim & Farm, INQUINOA CONICET, RA-4000 San Miguel de Tucuman, Tucuman, ArgentinaUniv Nacl Tucuman, INSIBIO CONICET, RA-4000 San Miguel de Tucuman, Tucuman, ArgentinaUniversidade Federal de São Paulo, Dept Ciencias Saude, Santos, SP, BrazilUniv Estadual Campinas, Fac Food Engn, Dept Food Sci, BR-13083862 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Ciencias Saude, Santos, SP, BrazilWeb of Scienc

El más antiguo platyperlidae (insecta, perlida= plecoptera) en depósitos del triásico superior temprano del sur de Sudamérica

The new insect species Platyperla marquati sp. nov. described herein is represented by a nymphal stage and belongs to the Order Perlida (= Plecoptera) Latreille (stoneflies). It comes from the uppermost section of the Potrerillos Formation, which crops out south of Cerro Cacheuta, at the southernmost end of the Precordillera (Mendoza Province, Argentina). The early Late Triassic Potrerillos/Cacheuta sedimentary succession in this area includes fluvial, deltaic and lacustrine facies that reflect deposition in the border of the Cacheuta depocenter of the Cuyo Basin. This is the second complete insect and the first autochthonous aquatic insect from Triassic beds in Argentina, and also the first record of the family Platyperlidae in Gondwana. This finding demonstrates the similarity of aquatic insect faunas in Mesozoic deposits all over the world, at least of the morpho ecological types of the aquatic stages. The lacustrine insect fauna began evolving during the Triassic and became diverse during the Jurassic and Early Cretaceous. Detailed geological studies revealed that levels equivalent to the middle Triassic lower units of the Uspallata Group (Río Mendoza and Cerro de Las Cabras formations) lie exposed on the southeastern flank of Cerro Cacheuta. Therefore, a new geological map and interpretation for this area are also presented.El nuevo insecto aquí descripto, Platyperla marquati sp. nov., está representado por un estadio ninfal y pertenece al Orden Perlida (=Plecoptera) Latreille. Este ejemplar proviene de la sección superior de la Formación Potrerillos, que aflora en el sur del Cerro Cacheuta, en el extremo sur de la Precordillera (Provincia de Mendoza, Argentina). La secuencia sedimentaria Potrerillos/Cacheuta en esta área de edad Triásico Tardío temprano, comprende facies depositadas en ambientes fluvial, deltaico y lacustre en un borde del depocentro Cacheuta de la Cuenca Cuyana. Este es el segundo insecto completo y el primero típicamente acuático hallado en los niveles del Triásico de la Argentina y también el primer registro de la Familia Platyperlidae en Gondwana. El hallazgo demuestra las semejanzas de la fauna de insectos acuáticos durante el Mesozoico a nivel mundial, por lo menos con respecto a los tipos morfo-ecológicos de los sistemas acuáticos pasados. En el Triásico, la fauna de insectos lacustres comienza su evolución llegando a tener un mayor desarrollo durante el Jurásico y Cretácico Inferior. Estudios geológicos detallados han revelado que niveles equivalentes a las unidades inferiores del Grupo Uspallata (formaciones Río Mendoza y Cerro de Las Cabras) afloran en el flanco sureste del Cerro Cacheuta. Por lo tanto se presenta un nuevo mapa e interpretación geológica para esta área.Fil: Gallego, Oscar Florencio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Rebori, Luis O. No especifica;Fil: Zavattieri, Ana Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Sinitshenkova, Nina. Borissiak Paleontological Institute, Russian Academy of Sciences; RusiaFil: Lara, Maria Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Martins Neto, Rafael G.. Universidade Estadual Do Ceara; Brasi