730 research outputs found

    Evolution and identity of synapsid carpal bones

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    To date there is little information on carpal bone homology in late Palaeozoic and Mesozoic Synapsida. Crucial to the understanding of homology in synapsid carpal elements is the fact that different nomenclatures are used for the carpals of non-mammaliamorph Synapsida (Gegenbauer?s canonical nomenclature) and Mammaliaformes (mammalian nomencla-ture). The homologies of the carpals of non-mammaliamorph synapsids and mammals were established early last century and have not been reviewed since then. Here we provide a detailed study of the carpal bones of synapsids ranging in age from the early Permian to Late Cretaceous. The mammaliamorph lunate, previously considered the homologue of the intermedium of non-mammaliamorph synapsids, is interpreted here as homologous to their lateral centrale. We interpret the single mammaliamorph centrale as a homologue of the medial centrale of non-mammaliamorph synapsids. In some synapsid specimens, we found that one or two centralia are fused to the radiale (e.g., the gorgonopsian Arctognathus and tritylodontid Bienotheroides), supporting a digging habit. A third centrale is present in the therocephalian Theriognathus, very likely an abnormal duplication. An additional medial bone in a biarmosuchian was interpreted as a prepollex/sesamoid. A cartilaginous prepollex/sesamoid may also have been present in several non-mammaliamorph synapsids, which have an open space proximal to distal carpal I. Distal carpal V is completely lost in dicynodonts and it is mainly fused to distal carpal IV in the adult stage of most other therapsid groups, but showed a delayed development in most non-mammaliamorph cynodonts. In mammaliamorphs, distal carpal V is not present. Our observations provide an up-dated revision of synapsid carpal homologies, mainly on the basis of position and anatomical contacts and also taking into account the results of embryological studiesFil: Kummell, S.. University Witten/herdecke; AlemaniaFil: Abdala, Nestor Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; ArgentinaFil: Sassoon, J.. University Of Bristol; Reino UnidoFil: Abdala, Virginia Sara Luz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Biodiversidad Neotropical. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Instituto de Biodiversidad Neotropical. Instituto de Biodiversidad Neotropical; Argentin

    Use of multivariate analysis in the non-genetic factors assessment of Creole goats

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    El peso al nacimiento en caprinos es un factor que siempre se pondera en los esquemas productivos por estar positivamente correlacionado con la tasa de crecimiento, con el tamaño del adulto, con el tiempo que tardan las crías en alcanzar peso de faena y con el tipo de alimentación que reciben. El peso al nacimiento varía en las distintas razas por ser determinado genéticamente. Hay productores que llegan a cambiar la raza de cabra buscando mejores pesos al nacimiento y desarrollos más precoces. Existen, sin embargo, factores no genéticos, que influyen en el peso al nacimiento y el desarrollo inicial que pueden llevar a confundir los resultados cuando se comparan diferentes razas buscando la producción de cabritos de mejores pesos al nacimiento y desarrollos más precoces. Sexo y número de camada son dos factores no genéticos relevantes en la determinación del peso al nacimiento y ya han sido demostrados en otras razas. En cabras Criollas, además de estos, se detecta que edad de la madre, número de parto de la madre, y mes de nacimiento también influyen. Se realizó un estudio de la influencia de todas estas variables en el peso al nacimiento y desarrollo inicial en un rebaño caprino de la Universidad Nacional de Santiago del Estero (UNSE), en el que se pesaron crías al nacimiento y en desarrollo inicial en cinco pariciones sucesivas. Se aplicó un análisis conjunto de todas las variables o multivariado, empleándose el método de componentes principales ACP, el cual detectó relaciones muy estrechas entre las variables en los tres ejes principales: 1) edad de la madre con número de parto, 2) peso con el tamaño de la camada y 3) otras relaciones, aunque débiles entre sexo y tamaño de camada. El ACP sirvió para sintetizar la información y mejorar la eficiencia en la interpretación de resultados, concentrando a los ejemplares en base a la influencia de las variables estudiadas con sus respectivos pesos al nacimiento, siendo los grupos 2 y 3 los de mayores pesos (3,18 kg y 3.4 kg respectivamente) y los bajos pesos para los grupos 1 y 4 (2,22 kg y 2,25 kg promedio, respectivamente).In goats, birth weight is a factor that is always taken into account in the production systems since it correlates positively with growth rate, with adult size, with the time required for the offspring reach slaughter weight and with the type of food they receive. Birth weight varies in different races to be genetically determined. There are breeders who change the race of goat focusing on the better birth weight and more early development. However, there are non-genetic factors that influence on the birth weight and early development that can lead to confusing results when comparing different races to looking offspring production of better birth weight and early development. Sex and number of litter are two non genetic factors relevant in determining birth weight, that in addition already it was demonstrated in other races. In Creole goats in addition to these, we found that age of mother, calving number of the mother, and birth month also have influence. A study of the influence of these variables on birth weight and initial development in a goat herd was conducted at the Na-tional University of Santiago del Estero. In this study the offspring were weighed at birth and during early developmental conducted in five successive calving. A pooled analysis of all variables or multivariate analyzes were applied, using the method of principal component ACP, which detect very close relations between the variables in the three major axis: 1) age of mother with calving number, 2) weight with the litter size and 3) other relationships, though weak between sex and litter size. This method, ACP, helped to summarize information and improving efficiency in the interpretation of results, bringing together animals based on the influence of the variables studied and their birth weight. Thus the groups 2 and 3 they presented the higher weights (3.18 kg and 3.4 kg respectively), and groups 1 and 4, lower weights (2.22 kg and 2.25 kg average respectively).Fil: David, R. N.. Universidad Nacional de Santiago del Estero. Facultad de Agronomía y Agroindustrias; ArgentinaFil: Abdala, G. C.. Universidad Nacional de Santiago del Estero. Facultad de Agronomía y Agroindustrias; ArgentinaFil: Abdala, María Eugenia. Universidad Nacional de Santiago del Estero. Facultad de Agronomía y Agroindustrias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lescano, J. A.. Universidad Nacional de Santiago del Estero. Facultad de Agronomía y Agroindustrias; Argentin

    Tingkat Kesukaan Konsumen Terhadap Ikan Cakalang (Katsuwonus Pelamis L.) Asap Yang Direndam Dalam Ekstrak Kulit Manggis

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    The purpose of this study was to determine consumer acceptance of smoked skipjack (Katsuwonus pelamis L) pre-treated in a solution of mangosteen peel with a concentration of 3%, 4% and 5%, in various soaking time 15 min or 30 min. The results showed that the pH and moisture content were relatively constant. Based on sensory evaluation, smoked fish pre-treated with 5% mangosteen peel and soaked for 30 min had higher value of taste, odor, and texture attribute

    Ontogenetic growth in the crania of Exaeretodon argentinus (Synapsida: Cynodontia) captures a dietary shift

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    Background. An ontogenetic niche shift in vertebrates is a common occurrence where ecology shifts with morphological changes throughout growth. How ecology shifts over a vertebrate’s lifetime is often reconstructed in extant species—by combining observational and skeletal data from growth series of the same species—because interactions between organisms and their environment can be observed directly. However, reconstructing shifts using extinct vertebrates is difficult and requires well-sampled growth series, specimens with relatively complete preservation, and easily observable skeletal traits associated with ecologies suspected to change throughout growth, such as diet. Methods. To reconstruct ecological changes throughout the growth of a stem-mammal, we describe changes associated with dietary ecology in a growth series of crania of the large-bodied (∼2 m in length) and herbivorous form, Exaeretodon argentinus (Cynodontia: Traversodontidae) from the Late Triassic Ischigualasto Formation, San Juan, Argentina. Nearly all specimens were deformed by taphonomic processes, so we reconstructed allometric slope using a generalized linear mixed effects model with distortion as a random effect. Results. Under a mixed effects model, we find that throughout growth, E. argentinus reduced the relative length of the palate, postcanine series, orbits, and basicranium, and expanded the relative length of the temporal region and the height of the zygomatic arch. The allometric relationship between the zygomatic arch and temporal region with the total length of the skull approximate the rate of growth for feeding musculature. Based on a higher allometric slope, the zygoma height is growing relatively faster than the length of the temporal region. The higher rate of change in the zygoma may suggest that smaller individuals had a crushing-dominated feeding style that transitioned into a chewing-dominated feeding style in larger individuals, suggesting a dietary shift from possible faunivory to a more plant-dominated diet. Dietary differentiation throughout development is further supported by an increase in sutural complexity and a shift in the orientation of microwear anisotropy between small and large individuals of E. argentinus. A developmental transition in the feeding ecology of E. argentinus is reflective of the reconstructed dietary transition across Gomphodontia, wherein the earliest-diverging species are inferred as omnivorous and the well-nested traversodontids are inferred as herbivorous, potentially suggesting that faunivory in immature individuals of the herbivorous Traversodontidae may be plesiomorphic for the clade.Fil: Wynd, Brenen. No especifíca;Fil: Abdala, Nestor Fernando. Fundación Miguel Lillo; Argentina. University of the Witwatersrand; Sudáfrica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; ArgentinaFil: Nesbitt, Sterling J.. No especifíca

    Youngest dinocephalian fossils extend the Tapinocephalus Zone, Karoo Basin, South Africa.

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    The dinocephalians (Synapsida, Therapsida) were one of the dominant tetrapod groups of the Middle Permian (Guadalupian Epoch, ∼270-260 million years ago) and are most abundantly recorded in the Tapinocephalus Assemblage Zone (AZ) of the Main Karoo Basin, South Africa. Dinocephalians are thought to have become extinct near the top of the Abrahamskraal Formation of the Beaufort Group and their disappearance is one criterion used to define the base of the overlying Pristerognathus AZ. Because of the abundance of fossils in the Karoo, the Beaufort Group biozones form the biostratigraphic standard for later Permian terrestrial tetrapod ecosystems, so their stratigraphic delineation is of great importance to Permian palaeobiology. We report two new specimens of the rare tapinocephalid dinocephalian Criocephalosaurus from the lowermost Poortjie Member, which makes them the youngest dinocephalians known from the Main Karoo Basin and extends the Tapinocephalus AZ from the Abrahamskraal Formation up into the Teekloof Formation. The extension of the Tapinocephalus AZ relative to the lithostratigraphy potentially affects the biozone or biozones to which a fossil species can be attributed; this extension has implications for biostratigraphic correlations within the Main Karoo Basin as well as with other basins across Gondwana. These discoveries also indicate that a population of herbivorous tapinocephalids survived as rare constituents of the tetrapod fauna after most generic richness within the clade had already been lost.NCS201

    Reptile species persistence under climate change and direct human threats in north-western Argentina

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    Protected areas have been established historically in residual places where the potential for extractive uses is low, implying that places at risk are usually underprotected. Argentina is no exception,with fewprotected areas established in productive regions that are prone to conversion. Here, using reptiles as a study group and considering the most important human threats in north-westernArgentina,we estimated priority conservation areas where we expect species to persist in the face of climate change and land conversion. Protected areas cover no more than 9% of the study region, but represent less than 15% of reptile distributions. There are great opportunities for improving the conservation status in the region by protecting only 8% more of north-western Argentina, with the level of species protection inside the protected area network increasing almost four-fold, reaching 43% of species distributions on average and 59% of the distributions of threatened reptiles. Fortunately, the highest diversity of reptiles in the region does not match the places targeted for agriculture expansion. Our findings suggest that future prioritization schemes should embrace other groups that are especially diverse in the Chaco ecoregion, which overlaps with our study area.FONCYT and SECYTUNC. RL’s research has been constantly funded by CNPq (grants #308532/2014-7, 479959/2013-7, 407094/2013-0 and 563621/2010-9), O Boticário Group Foundation for Nature Protection (grant #PROG_0008_2013) and CNCFlora. This paper is a contribution of the Brazilian Network on Global Climate Change Research funded by CNPq (grant #437167/2016-0) and FINEP (grant #01.13.0353.00). RLP acknowledges the support of the Australian Research Council

    Primer registro de <i>Liolaemus puritamensis</i> Núñez & Fox, 1989 para el sur de Bolivia (Reptilia, Squamata, Liolaemidae)

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    La revisión exhaustiva de los ejemplares del grupo montanus depositados en las colecciones científicas del área de herpetología en la Colección Boliviana de Fauna, permite ampliar la distribución conocida de la especie Liolaemus puritamensis y considerarla como nuevo registro para Bolivia.Asociación Herpetológica Argentina (AHA

    Endophytic Bacteria Improve Seedling Growth of Sunflower Under Water Stress, Produce Salicylic Acid, and Inhibit Growth of Pathogenic Fungi

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    Endophytic bacterial strains SF2 (99.9% homology with Achromobacter xylosoxidans), and SF3 and SF4 (99.9% homology with Bacillus pumilus) isolated from sunflower grown under irrigation or drought were selected on the basis of plant growth-promoting bacteria (PGPB) characteristics. Aims of the study were to examine effects of inoculation with SF2, SF3, and SF4 on sunflower cultivated under water stress, to evaluate salicylic acid (SA) production by these strains in control medium or at Ψa = -2.03 MPa, and to analyze effects of exogenously applied SA, jasmonic acid (JA), bacterial pellets, and bacterial supernatants on growth of pathogenic fungi Alternaria sp., Sclerotinia sp., and Verticillum sp. Growth response to bacterial inoculation was studied in two inbred lines (water stress-sensitive B59 and water stress-tolerant B71) and commercial hybrid Paraiso 24. Under both water stress and normal conditions, plant growth following inoculation was more strongly enhanced for Paraiso 24 and B71 than for B59. All three strains produced SA in control medium; levels for SF3 and SF4 were higher than for SF2. SA production was dramatically higher at Ψa = -2.03 MPa. Exogenously applied SA or JA caused a significant reduction of growth for Sclerotinia and a lesser reduction for Alternaria and Verticillum. Fungal growth was more strongly inhibited by bacterial pellets than by bacterial supernatants. Our findings indicate that these endophytic bacteria enhance growth of sunflower seedlings under water stress, produce SA, and inhibit growth of pathogenic fungi. These characteristics are useful for formulation of inoculants to improve growth and yield of sunflower crops. © 2010 Springer Science+Business Media, LLC.Fil: Forchetti, Gabriela Noemi. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Cátedra de Fisiología Vegetal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Masciarelli, Oscar Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Cátedra de Fisiología Vegetal; ArgentinaFil: Izaguirre, Maria J.. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Cátedra de Fisiología Vegetal; ArgentinaFil: Alemano, Sergio Gabriel. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Cátedra de Fisiología Vegetal; ArgentinaFil: Alvarez, Daniel. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Córdoba. Estación Experimental Agropecuaria Manfredi. Departamento de Producción Vegetal; ArgentinaFil: Abdala, Guillermina Irene. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Cátedra de Fisiología Vegetal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
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