801 research outputs found

    Configured distribution of the celiac artery in blue-fronted amazon (Amazona aestiva)

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    Foram descritas a origem e a distribuição da artĂ©ria celĂ­aca em 20 papagaios-verdadeiros (Amazona aestiva), por meio do preenchimento do sistema arterial com solução de lĂĄtex corado, fixado em solução de formol, para posterior dissecação de seus ramos colaterais. Como primeiro ramo, a artĂ©ria cĂ©lica emitiu a artĂ©ria proventricular dorsal, que seguiu para o ventrĂ­culo como artĂ©ria gĂĄstrica dorsal e, em seguida, enviou a artĂ©ria proventricular ventral, que em 85% dos exemplares se originou diretamente da artĂ©ria celĂ­aca, ou do seu ramo esquerdo em 15%. Em 25% dos casos, a artĂ©ria esplĂȘnica foi emitida antes da bifurcação em ramo esquerdo e direito. O ramo esquerdo foi responsĂĄvel pela origem de ramos proventriculares, ramos pilĂłricos, artĂ©ria esplĂȘnica e artĂ©ria proventricular ventral, a qual emitiu ramos ao proventrĂ­culo e ao esĂŽfago. A artĂ©ria celĂ­aca tambĂ©m originou as artĂ©rias gĂĄstrica ventral e gĂĄstrica esquerda, que foram responsĂĄveis pela emissĂŁo da artĂ©ria hepĂĄtica esquerda. O ramo direito emitiu artĂ©rias esplĂȘnicas − que variaram de uma a sete −, duodenal − destinada ao segmento mais caudal da alça ascendente do duodeno, hepĂĄtica direita − para o lobo direito do fĂ­gado. Em seu segmento terminal, o ramo direito dividiu-se em artĂ©rias gĂĄstrica direita − para o ventrĂ­culo −, pancreaticoduodenal − para o pĂąncreas, alças ascendente e descendente do duodeno e segmentos cranial do Ă­leo e caudal do jejuno. A irrigação determinada pela artĂ©ria celĂ­aca nos papagaios segue o que Ă© proposto para aves de outros gĂȘneros, apresentando divergĂȘncias como ausĂȘncia das artĂ©rias vesicular e ileocecal, bem como da vesĂ­cula biliar e ceco. _________________________________________________________________________________ ABSTRACTThis research was performed aiming to describe the origin and the distribution of the celiac artery in 20 blue fronted amazon (Amazona aestiva), through the completion of their circulatory system with an aqueous solution of colored latex, followed by fixation in formol for later dissection of the collateral branches. The first branch emitted the proventricular dorsal artery that headed to the ventricle as gastric dorsal artery and next emitted the proventricular ventral artery which originated on the celiac artery in 85% of the cases and in 15% had its origin on the left branch of the celiac artery. In 25% of the cases the splenic artery was emitted before the bifurcation on left and right branches. The left branch was responsible for the origin of the proventricular branches, piloric branches, splenic artery and proventricular artery, which emitted branches to the proventricle and esophagus. The celiac artery also emitted the gastric ventral artery and left gastric. The right branch emitted splenic arteries (that varied from a number of seven); duodenal bound for the more caudal segment of the ascendant segment of the duodenum and the right hepatica to the right liver lobe. On its terminal segment the right branch was divided into right gastric arteries to the ventricle and pancreaticduodenal to the pancreas, ascendant and descendant braces of the duodenum and to the cranial segments of the ileum and caudal of the jejune. The irrigation provided by the celiac artery in parrots remains the same as described for other bird genders showing as divergences: the lack of vesicular arteries and ileocecal as well the gall bladder and the cecos

    Detection of quantum non-Markovianity close to the Born-Markov approximation

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    We calculate in an exact way the conditional past-future correlation for the decay dynamics of a two-level system in a bosonic bath. Different measurement processes are considered. In contrast to quantum memory measures based solely on system propagator properties, here memory effects are related to a convolution structure involving two system propagators and the environment correlation. This structure allows to detect memory effects even close to the validity of the Born-Markov approximation. An alternative operational-based definition of environment-to-system backflow of information follows from this result. We provide experimental support to our results by implementing the dynamics and measurements in a photonic experiment.Fil: Silva, Thais De Lima. Universidade Federal do Rio de Janeiro; BrasilFil: Walborn, Stephen P.. Universidade Federal do Rio de Janeiro; BrasilFil: Santos, Marcelo F.. Universidade Federal do Rio de Janeiro; BrasilFil: Aguilar, Gabriel H.. Universidade Federal do Rio de Janeiro; BrasilFil: Budini, Adrian Adolfo. ComisiĂłn Nacional de EnergĂ­a AtĂłmica. Centro AtĂłmico Bariloche; Argentina. Universidad TecnolĂłgica Nacional; Argentina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Patagonia Norte; Argentin

    Evaluation of the agreement by examiners according to classifications of third molars

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    Objectives. This study recorded and evaluated the intra- and inter-group agreement degree by different examiners for the classification of lower third molars according to both the Winter's and Pell and Gregory's systems. Study Design. An observational and cross-sectional study was realized with forty lower third molars analyzed from twenty digital panoramic radiographs. Four examiner groups (undergraduates, maxillofacial surgeons, oral radiologists and clinical dentists) from Aracaju, Sergipe, Brazil, classified them in relation to angulation, class and position. The variance test (ANOVA) was applied in the examiner findings with significance level of p<0.05 and confidence intervals of 95%. Results. Intra- and inter-group agreement was observed in Winter's classification system among all examiners. Pell and Gregory's classification system showed an average intra-group agreement and a statistical significant difference to position variable in inter-group analysis with greater disagreement to the clinical dentists group (p<0.05). Conclusions. High reproducibility was associated to Winter's classification, whereas the system proposed by Pell and Gregory did not demonstrate appropriate levels of reliability. © Medicina Oral

    Placentation in the paca (Agouti paca L)

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    BACKGROUND: The paca is a South American rodent with potential as a commercial food animal. We examined paca placenta as part of a wider effort to understand the reproductive biology of this species. METHODS: Thirteen specimens between midgestation and term of pregnancy were studied by light and transmission electron microscopy. RESULTS: The placenta is divided into several lobes separated by interlobular trophoblast. Maternal arterial channels and fetal veins are found at the centre of each lobe. In the labyrinth, maternal blood flows through trophoblast-lined lacunae in close proximity to the fetal capillaries. The interhaemal barrier is of the haemomonochorial type with a single layer of syncytiotrophoblast. Caveolae occur in the apical membrane of the syncytiotrophoblast and recesses in the basal membrane, but there is no evidence of transtrophoblastic channels. The interlobular areas consist of cords of syncytiotrophoblast defining maternal blood channels that drain the labyrinth. Yolk sac endoderm covers much of the fetal surface of the placenta. The subplacenta comprises cytotrophoblast and syncytiotrophoblast. There are dilated intercellular spaces between the cytotrophoblasts and lacunae lined by syncytiotrophoblast. In the junctional zone between subplacenta and decidua, there are nests of multinucleated giant cells with vacuolated cytoplasm. The entire placenta rests on a pedicle of maternal tissue. An inverted yolk sac placenta is also present. The presence of small vesicles and tubules in the apical membrane of the yolk sac endoderm and larger vesicles in the supranuclear region suggest that the yolk sac placenta participates in maternal-fetal transfer of protein. CONCLUSION: The paca placenta closely resembles that of other hystricomorph rodents. The lobulated structure allows for a larger exchange area and the development of precocial young

    ï»żNew segregates from the Neotropical genus Stryphnodendron (Leguminosae, Caesalpinioideae, mimosoid clade)

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    Non-monophyly is a prominent issue in mimosoid legumes, even in some of the less speciose genera such as the neotropical genus Stryphnodendron. This genus includes 35 species occurring from Nicaragua to Southern Brazil mostly in humid forests and savannas. Previous taxonomic studies of Stryphnodendron have highlighted morphologically distinct groups within the genus, recognized by differences on leaves (number of pinnae and size of leaflets), inflorescences (a simple or compound thyrse), and fruit types (legume, nucoid legume or follicle). Recent phylogenetic analyses have confirmed the non-monophyly of Stryphnodendron, supporting the recognition of three independent and morphologically well-delimited genera. Here we re-circumscribe Stryphnodendron and propose the two new genera Gwilymia and Naiadendron. In addition, we also provide an updated taxonomic account of the closely related genus Microlobius, including the proposal of a lectotype for the single species in the genus

    Membran Kitosan Padat dari Cangkang Rajungan (Portunus pelagicus) dan Aplikasinya sebagai Adsorben Ion Logam Cu(II) dan Cr(III)

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    Mulches bring several benefits to lettuce cultivation. This work evaluated the effect of mulches on the cultivation of iceberg lettuce, cv. Lucy Brown. The treatment plots were: 1- no mulch and no weed control (control); 2- no mulch and weed control every 15 days; 3- sugarcane bagasse mulch of 2 cm thickness; 4- black plastic mulch; 5- double-faced plastic mulch (silver/black). Data were collected in regard to plant cycle when in the field, amount of chlorophyll in the leaves, productivity (individual weight per head) and amount of nutrients absorbed by the leaves. Double-faced plastic mulch provides the highest productivity and the highest values for the amount of chlorophyll, nitrogen, phosphorus, sulfur, boron and iron accumulation in the leaves.A utilização da cobertura do solo pode trazer inĂșmeros benefĂ­cios ao cultivo de alface. Este experimento teve como objetivo avaliar o efeito de tipos de coberturas de solo no cultivo de alface tipo americana cv. Lucy Brown. Os tratamentos foram: 1- canteiro sem cobertura e sem capina (testemunha), 2- canteiro sem cobertura, com capina quinzenal, 3- canteiro com cobertura de bagaço de cana de 2 cm de espessura, 4- canteiro com cobertura de plĂĄstico preto, 5- canteiro com cobertura de plĂĄstico dupla face (prateado/preto). Foram avaliados o ciclo das plantas no campo, a quantidade de clorofila nas folhas, a produção em peso individual de cabeça e a quantidade de nutrientes absorvidos nas folhas. A utilização de cobertura plĂĄstica do tipo dupla face proporcionou os maiores valores mĂ©dios de produção. Foi tambĂ©m o tratamento em que foram obtidos os maiores valores para quantidade de clorofila, nitrogĂȘnio, fĂłsforo, enxofre, boro e ferro acumulado nas folhas

    Magnon delocalization in ferromagnetic chains with long-range correlated disorder

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    We study one-magnon excitations in a random ferromagnetic Heisenberg chain with long-range correlations in the coupling constant distribution. By employing an exact diagonalization procedure, we compute the localization length of all one-magnon states within the band of allowed energies EE. The random distribution of coupling constants was assumed to have a power spectrum decaying as S(k)∝1/kαS(k)\propto 1/k^{\alpha}. We found that for α<1\alpha < 1, one-magnon excitations remain exponentially localized with the localization length Ο\xi diverging as 1/E. For α=1\alpha = 1 a faster divergence of Ο\xi is obtained. For any α>1\alpha > 1, a phase of delocalized magnons emerges at the bottom of the band. We characterize the scaling behavior of the localization length on all regimes and relate it with the scaling properties of the long-range correlated exchange coupling distribution.Comment: 7 Pages, 5 figures, to appear in Phys. Rev.
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