2,800 research outputs found

    Apología de la pena en dos visiones reduccionistas de la cuestión criminal en Argentina

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    Fil: Cid Ferreira, Lucia. Universidad Nacional de Tucumán. Facultad de Derecho y Ciencias Sociales. Centro de Investigaciones Sociológicas

    Bayesian Comparison of Interacting Scenarios

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    We perform a Bayesian model selection analysis for different classes of phenomenological coupled scenarios of dark matter and dark energy with linear and non-linear interacting terms. We use a combination of some of the latest cosmological data such as type Ia supernovae (SNe Ia), cosmic chronometers (CC), cosmic microwave background (CMB) and two sets of baryon acoustic oscillations measurements, namely, 2-dimensional angular measurements (BAO2) and 3-dimensional angle-averaged measurements (BAO3). We find weak and moderate evidence against two-thirds of the interacting scenarios considered with respect to őõ\LambdaCDM when the full joint analysis is considered. About one-third of the models provide a description to the data as good as the one provided by the standard model. Our results also indicate that either SNe Ia, CC or BAO2 data by themselves are not able to distinguish among interacting models or őõ\LambdaCDM but the standard BAO3 measurements and the combination with the CMB data are indeed able to discriminate among them. We find that evidence disfavoring interacting models is weaker when we use BAO2 (data claimed to be almost model-independent) instead of the standard BAO3 measurements. These results help select classes of viable and non-viable interacting models in light of current data.Comment: 32 page

    3 - Contrats en immobilisation

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    Densidade b√°sica (g.cm-3: peso seco / volume √ļmido) da madeira foi determinada para 13 das principais esp√©cies arb√≥reo-arbustivas de um ecossistema de "campina" (caatinga amaz√īnica) situado em Roraima, extremo norte da Amaz√īnia brasileira. As amostras de madeira para o c√°lculo da densidade b√°sica de cada esp√©cie foram compostas por "discos amostrais" (casca, alburno e cerne) de diferentes classes diam√©tricas. No total, foram amostrados 98 indiv√≠duos, perfazendo 150 pe√ßas de madeira (52 com di√Ęmetro 4,8cm). A esp√©cie de maior densidade m√©dia foi Matayba arborescens (Aubl.) Radlk. (0,68 g.cm-3), seguida de Humiria balsamifera (Aubl.) St. Hill. (0,67 g.cm-3) e Pera schomburgkiana M√ľel. Arg. (0,64 g.cm-3). As classes de menor di√Ęmetro foram tamb√©m as de menor valor absoluto: 0,59 ¬Ī 0,06 (DP) g.cm-3 ( 4,8cm). A m√©dia ponderada pela biomassa do ecossistema foi de 0,64 ¬Ī 0,08 g.cm-3. Este resultado √© 15,2% inferior ao comumente utilizado para transforma√ß√£o de volume de madeira em biomassa para ecossistemas de "campina" na Amaz√īnia, influenciando diretamente nos c√°lculos de emiss√£o de gases do efeito estufa.Wood density (g.cm-3: oven-dry weight / wet volume) was determined for 13 of the main tree species of a "campina" ecosystem (Amazon caatinga) located in Roraima, north portion of Brazilian Amazonia. The wood samples for calculation of the density of each species were "sample disks" (bark, sapwood and heartwood) of different diameter classes. In total, 98 individuals were sampled in 150 wood pieces (52 with diameter 4.8cm). The species with the highest wood density was Matayba arborescens (Aubl.) Radlk. (0.68 g.cm-3), followed by Humiria balsamifera (Aubl.) St. Hill. (0.67 g.cm-3) and Pera schomburgkiana M√ľel. Arg. (0.64 g.cm-3). The smaller diameter classes were also those with lower density: 0.59 ¬Ī 0.06 (SD) g.cm-3 ( 4.8cm). The weighted mean by biomass of the ecosystem was 0.64 ¬Ī 0.08 g.cm-3. This result is lower by 15.2% than that presently used for transformation of wood volume in biomass for "campina" ecosystems in Amazonia, influencing directly in the calculations of greenhouse gas emissions

    Algebraic Cryptanalysis and RFID Authentication

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    Apología en la pena en dos visiones reduccionistas de la cuestión criminal en Argentina

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    Con la perspectiva de la sociología y de la criminología crítica, este trabajo pretende realizar una exposición y una crítica de ambas visiones de la cuestión criminal, apuntando los problemas teóricos y prácticos que implican.Facultad de Humanidades y Ciencias de la Educació

    An√°lise comparativa de vegeta√ß√£o lenhosa do ecossistema campina na Amaz√īnia brasileira

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    Amazonian campinas are sclerophytic vegetation occurring in white sand soils. Although in the beginning they were just mentioned for the rio Negro basin, it is now know that the campinas are widely distributed in the Amazon and some other areas of Tropical America. Amazonian campinas occur as enclaves in areas with dominated by other vegetation types such as rain forests, savannas or campinarana forests. The sandy soils colonized by campinarana plants could be of different origins, such as: a) beds of ancient bodies of water that dry ; b) the sandy profiles derived from the erosion of sandstones from the Guiana Shield or the Brazilian Shield, and; c) ancient sand dunes of eolian origin. This present thesis is aiming to describe and compare from the floristic and phytosociologic point of view, nine Amazonian campinas. Only arboreal and shrubby species with diameter at breast height (DAP) > 5 cm were studied. The nine campinas studied contained, 252 species belonging to 121 genera and 44 families. The families of greatest floristic abundance were Fabaceae, Mytaceae, Rubiaceae, Clusiaceae, Malpighiaceae, and Annonaceae. The genera of most importance were Clusia, Emmotum, Pagamea, Tapirira, Eugenia, Matayba, Myrcia and Ouratea. The nine sampled areas exibited a high proportion of unique species: 72.6% of the species were just registered in one of the campinas. The high proportion of exclusive species resulted in a great floristic comparative distance among the campinas (Jaccard distance ranging from 0.471 to 0.942). In contrast, seven species (2.8% of total) occurred in more than five campinas. These species have wide neotropical distribution and occur in different physiognomies: Humiria balsamifera Aubl., Emmotum nitens Miers, Pagamea guianensis Aubl., Tapirira guianensis Aubl., Byrsonima crassifolia (L.) Kunth., Ouratea spruceana Engl. e Alchornea discolor Poepp. The analysis of the species distribution together with the floristic similarity and MDS analysis have found some phytogeographic patterns for the Amazonian campinas, such as: a) great floristic afinity among Amazonian campinas and the Guiana Shield vegetation and Venezuela-Colombia Llanos; b) campinas in contact with Amazon basin and Brazilian Shield, like the Serra do Cachimbo ones, show greater influence from the Cerrado vegetation; c) campinas from eastern Amazon has shown greater influence from the Guiana and Brazilian Shield floras; d) Low afinity between the Amazonian campinas and restinga vegetation from the Atlantic cost; e) Amazonian campinas from the Brazilian western extreme, like Cruzeiro do Sul (Acre), are significantly different from the other ones. The results of this work reinforce the need of biodiversity conservation programs for the Amazonian campinas due to the great floristic divergence observed among them, large endemic potential and its occurrence on restricted isolated spots.As campinas amaz√īnicas s√£o forma√ß√Ķes vegetais escler√≥filas que se desenvolvem em solos de areia branca. Apesar de inicialmente citadas apenas para a bacia do Rio Negro, sabe-se atualmente que as campinas est√£o amplamente distribu√≠das na Amaz√īnia e em outras √°reas da Am√©rica Tropical. As campinas ocorrem como enclaves em √°reas com matriz de floresta ombr√≥fila, cerrado ou campinarana. Os substratos arenosos colonizados pelas plantas de campina podem ser de diferente natureza, tais como: (a) leitos de antigos corpos de √°gua que secaram, (b) perfis arenosos oriundos da decomposi√ß√£o de arenitos do Escudo Guianense e do Escudo Brasileiro, e (c) antigas dunas arenosas de origem he√≥lica. O presente trabalho teve como objetivo descrever e comparar, do ponto de vista flor√≠stico e fitossociol√≥gico, nove campinas na Amaz√īnia Brasileira. Foram estudadas apenas as esp√©cies arb√≥reas e arbustivas com di√Ęmetro na altura do peito (DAP) 5 cm. Foram registradas, nas nove campinas estudadas, 252 esp√©cies pertencentes a 121 g√™neros e 44 fam√≠lias. As fam√≠lias de maior riqueza flor√≠stica foram Fabaceae, Myrtaceae, Rubiaceae, Clusiaceae, Malpighiaceae e Annonaceae. Os g√™neros de maior import√Ęncia foram Clusia, Emmotum, Pagamea, Tapirira, Eugenia, Matayba, Myrcia e Ouratea. As nove campinas amostradas exibiram uma alta propor√ß√£o de esp√©cies exclusivas: 72,6% das esp√©cies foi registrada apenas em uma das campinas. A alta propor√ß√£o de esp√©cies exclusivas resultou em grande dist√Ęncia flor√≠stica entre as campinas estudadas (dist√Ęncia de Jaccard variando de 0,471 a 0,942). Em contraste, sete esp√©cies (2,8% do total) ocorreram em mais de cinco campinas. Estas esp√©cies, de ampla distribui√ß√£o neotropical e de ocorr√™ncia em diferentes fisionomias, s√£o: Humiria balsamifera Aubl., Emmotum nitens Miers, Pagamea guianensis Aubl., Tapirira guianensis Aubl., Byrsonima crassifolia (L.) Kunth., Ouratea spruceana Engl. e Alchornea discolor Poepp. A an√°lise de distribui√ß√£o das esp√©cies, juntamente com an√°lises de similaridade flor√≠stica e de ordenamento MDS (Escalonamento multi-dimensional n√£o-m√©trico) indicam alguns padr√Ķes fitogeogr√°ficos para as campinas, tais quais: (a) grande afinidade flor√≠stica entre as campinas amaz√īnicas e a vegeta√ß√£o do Escudo Guianense e dos Llanos Venezuelanos/Colombianos; (b) campinas no contato da bacia amaz√īnica com o Escudo Brasileiro ‚Äď como as da Serra do Cachimbo - apresentam maior influ√™ncia da vegeta√ß√£o do cerrado; (c) campinas do leste amaz√īnico apresentam influ√™ncia mista das floras do Escudo Guianense e do Escudo Brasileiro; (d) baixa afinidade da flora das campinas com a da Restinga Atl√Ęntica; (e) campinas do extremo oeste da Amaz√īnia brasileira ‚Äď como a de Cruzeiro do Sul (Acre) - s√£o altamente diferenciadas das demais. Os resultados aqui apresentados refor√ßam a necessidade de programas de conserva√ß√£o da biodiversidade das campinas amaz√īnicos, dada a alta diferencia√ß√£o flor√≠stica observada entre elas, a grande concentra√ß√£o de endemismos e sua ocorr√™ncia em manchas restritas e isoladas

    Toxicity Evaluation of Quantum Dots (ZnS and CdS) Singly and Combined in Zebrafish (Danio rerio)

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    This work was supported by the Applied Molecular Biosciences Unit- UCIBIO which is financed by national funds from FCT/MCTES (UID/Multi/04378/2019) and by the Associate Laboratory for Green Chemistry- LAQV which is financed by national funds from FCT/MCTES (UID/QUI/50006/2019) and by the Marine and Environmental Sciences Centre (MARE) which is financed by national funds from FCT/MCTES (UID/MAR/04292/2019).The exponential growth of nanotechnology has led to the production of large quantities of nanomaterials for numerous industrial, technological, agricultural, environmental, food and many other applications. However, this huge production has raised growing concerns about the adverse effects that the release of these nanomaterials may have on the environment and on living organisms. Regarding the effects of QDs on aquatic organisms, existing data is scarce and often contradictory. Thus, more information is needed to understand the mechanisms associated with the potential toxicity of these nanomaterials in the aquatic environment. The toxicity of QDs (ZnS and CdS) was evaluated in the freshwater fish Danio rerio. The fishes were exposed for seven days to different concentrations of QDs (10, 100 and 1000 ¬Ķg/L) individually and combined. Oxidative stress enzymes (catalase, superoxide dismutase and glutathione S-transferase), lipid peroxidation, HSP70 and total ubiquitin were assessed. In general, results suggest low to moderate toxicity as shown by the increase in catalase activity and lipid peroxidation levels. The QDs (ZnS and CdS) appear to cause more adverse effects singly than when tested combined. However, LPO results suggest that exposure to CdS singly caused more oxidative stress in zebrafish than ZnS or when the two QDs were tested combined. Levels of Zn and Cd measured in fish tissues indicate that both elements were bioaccumulated by fish and the concentrations increased in tissues according to the concentrations tested. The increase in HSP70 measured in fish exposed to 100 ¬Ķg ZnS-QDs/L may be associated with high levels of Zn determined in fish tissues. No significant changes were detected for total ubiquitin. More experiments should be performed to fully understand the effects of QDs exposure to aquatic biota.publishersversionpublishe
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