50 research outputs found

    Enfermidades determinadas pelo princípio radiomimético de Pteridium aquilinum (Polypodiaceae)

    Full text link

    Soil health: looking for suitable indicators. What should be considered to assess the effects of use and management on soil health?

    Full text link

    An Indication of Anisotropy in Arrival Directions of Ultra-high-energy Cosmic Rays through Comparison to the Flux Pattern of Extragalactic Gamma-Ray Sources

    Get PDF
    A new analysis of the data set from the Pierre Auger Observatory provides evidence for anisotropy in the arrival directions of ultra-high-energy cosmic rays on an intermediate angular scale, which is indicative of excess arrivals from strong, nearby sources. The data consist of 5514 events above 20 EeV with zenith angles up to 80 degrees. recorded before 2017 April 30. Sky models have been created for two distinct populations of extragalactic gamma-ray emitters: active galactic nuclei from the second catalog of hard Fermi-LAT sources (2FHL) and starburst galaxies from a sample that was examined with Fermi-LAT. Flux-limited samples, which include all types of galaxies from the Swift-BAT and 2MASS surveys, have been investigated for comparison. The sky model of cosmic-ray density constructed using each catalog has two free parameters, the fraction of events correlating with astrophysical objects, and an angular scale characterizing the clustering of cosmic rays around extragalactic sources. A maximum-likelihood ratio test is used to evaluate the best values of these parameters and to quantify the strength of each model by contrast with isotropy. It is found that the starburst model fits the data better than the hypothesis of isotropy with a statistical significance of 4.0 sigma, the highest value of the test statistic being for energies above 39 EeV. The three alternative models are favored against isotropy with 2.7 sigma-3.2 sigma significance. The origin of the indicated deviation from isotropy is examined and prospects for more sensitive future studies are discussed

    Structure and Dynamics of Heteroprotein Coacervates

    No full text
    International audienceUnder specific conditions, mixing two oppositely charged proteins induces liquid−liquid phase separation. The denser phase, or coacervate phase, can be potentially applied as a system to protect or encapsulate different bioactive molecules with a broad range of food and/or medical applications. The optimization of the design and efficiency of such systems requires a precise understanding of the structure and the equilibrium of the nanocomplexes formed within the coacervate. Here, we report on the nanocomplexes and the dynamics of the coacervates formed by two well-known, oppositely charged proteins β-lactoglobulin (β-LG, pI ≈ 5.2) and lactoferrin (LF, pI ≈ 8.5). Fluorescence recovery after photobleaching (FRAP) and solid-state nuclear magnetic resonance (NMR) experiments indicate the coexistence of several nanocomplexes as the primary units for the coacervation. To our knowledge, this is the first evidence of the occurrence of an equilibrium between quite unstable nanocomplexes in the coacervate phase. Combined with in silico docking experiments, these data support the fact that coacervation in the present heteroprotein system depends not only on the structural composition of the coacervates but also on the association rates of the proteins forming the nanocomplexes

    Aspectos clínico-patológicos da intoxicação experimental pelas sementes de Crotalaria mucronata (Fabaceae) em bovinos Experimental poisoning by Crotalaria mucronata (Fabaceae) seeds in cattle

    No full text
    Sementes moídas de Crotalaria mucronata Desv. (=Crotalaria striata DC., Crotalaria pallida Ait., Crotalaria saltiana), com nomes populares de "xique-xique" ou "guizo-de-cascavel", foram administradas por via oral a 9 bovinos. As doses diárias de 1g/kg, 2g/kg, 3g/kg cada uma a um bovino, e 5g/kg em dois de três bovinos, dadas durante 61 a 63 dias, não causaram intoxicação. A dose de 5g/kg em um bovino, 7,5g/kg em dois bovinos e 10g/kg em um bovino, dadas durante 47-61 dias, causaram sintomas entre 47 e 80 dias após o início da administração e a morte entre 3 horas e 5 dias após o início dos sintomas. Os principais sintomas foram pulso venoso positivo da veia jugular, respiração abdominal, taquicardia, inapetência, fezes ressequidas, edema sub-mandibular e fraqueza. Os achados de necropsia foram palidez pulmonar, hidropericárdio, hidrotórax, hidroperitôneo, edema de mesentério, aumento da consistência hepática, alterações de cor do fígado, dilatação de ventrículo cardíaco direito e edema da parede ruminal. As principais alterações histológicas concentraram-se nos pulmões, sob forma de espessamento das paredes alveolares e da parede das arteríolas com diminuição da luz e fibrose periarteriolar; havia também lesões hepáticas e cardíacas de menor importância. Pode-se concluir que as principais lesões causadas pela ingestão das sementes de C. mucronata durante períodos prolongados, devem-se à dificuldade de passagem do sangue pelos vasos pulmonares em função da hipertensão arterial decorrente de fibrose e espessamento arteriolar determinada pela ação pneumotóxica da planta.<br>Experiments were performed to define the clinical and pathological picture of prolonged administration of the seeds of Crotalaria mucronata Desv. to cattle, in order to obtain additional information about this toxicosis. The ground seeds were administered orally to 9 bovines. Doses of 1g/kg/day, 2g/kg/day, 3g/kg/day each in one bovine, and 5g/kg/day in two of three bovines, given for 61- 63 days, did not cause poisoning. Doses of 5g/kg, in one bovine, 7.5g/kg in two bovines and 10g/kg in one bovine, given for 47-61 days, caused symptoms between 47 and 80 days after the first administration and caused death between 3 hours and 5 days after the onset of symptoms. The main clinical signs were positive venous pulse of the jugular vein, abdominal breath, tachycardia, loss of appetite, dry feces, sub-mandibular edema and weakness. Bovines that did not die, were slaughtered 8 or 9 months after first administration. At necropsy pulmonary paleness, hydropericardium, hydrothorax, hydroperitoneum, mesenteric edema, augmented hepatic consistency, discoloration of the liver, right cardiac ventricle dilatation and ruminal wall edema were seen. The main histological lesions were thickening of the alveolar walls and of the arterioles with narrowing of their lumen, and periarteriolar fibrosis, besides hepatic and cardiac lesions of minor importance. It is concluded, that the lesions caused by ingestion of the seeds of C. mucronata over a long period are caused by the difficulties of blood passage through the pulmonar vessels due to fibrosis and thickening of the arteriolar walls through the pneumotoxic action of the plant
    corecore