1,084 research outputs found

    Rendimiento productivo y morfometría intestinal del pollo de engorde sometido a dietas con inclusión de espirulina (Arthrospira platensis)

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    The aim of this study was to determine the effect of spirulina (Arthrospira platensis) on productive performance (WG: weight gain, FI: feed intake, FCR: feed conversion ratio, EPEI: European productive efficiency index) and intestinal morphometry (VL: villus length,  VW: villus width, CD: crypt depth) in broilers. In total, 240 one-day-old male chicks from the Cobb 500 line were used, distributed into four treatments with six replicates of 10 chicks each. The treatments were: T0: base diet without spirulina (control), T1: base diet with 0.25% spirulina, T2: base diet with 0.5% spirulina, T3: base diet with 1% spirulina. A completely randomized block design was used. The effect of increasing levels of spirulina was evaluated by linear and quadratic polynomial orthogonal contrasts. The WG and FI variables showed quadratic trend while FCR and EPEI showed linear trend. The optimal level of spirulina that maximizes weight gain was 0.68% with a predictive value of 3330 g. The increasing levels of spirulina did not affect the morphometric measurements of VL and VW at the level of duodenum, jejunum and ileum; therefore, significant linear responses were obtained in CD and VL/CD in jejunum and in VL/CD in ileum as a response to the increasing levels of spirulina in the diet. It was concluded that the increasing levels of spirulina influence the productive performance under experimental conditions while they were not conclusive for intestinal morphometry in Cobb 500 chicks at 42 days of age.El objetivo del estudio fue determinar el efecto de la espirulina (Arthrospira platensis) sobre el rendimiento productivo (GP: ganancia de peso, CA: conversión alimenticia, ICA: índice de conversión alimenticia, IEPE: índice de eficiencia productiva europeo) y la morfometría intestinal (LV: longitud de vellosidad, AV: ancho de vellosidad, PC: profundidad de cripta y LV/PC: relación longitud de vellosidad/profundidad de cripta) en pollos de engorde. Se emplearon 240 pollos machos de un día de edad de la línea Cobb 500, distribuidos en cuatro tratamientos con seis réplicas de 10 pollos cada uno. Los tratamientos fueron: T0: dieta base sin espirulina (control), T1: dieta base con 0.25% de espirulina, T2: dieta base con 0.5% de espirulina, T3: dieta base con 1% de espirulina. Se empleó un diseño de bloques completamente al azar. El efecto de los niveles crecientes de espirulina se evaluó por contrastes ortogonales polinómicos de tipo lineal y cuadrático. Las variables GP y CA presentaron un comportamiento cuadrático mientras que el ICA e IEPE mostraron un comportamiento lineal. El nivel óptimo de espirulina que maximiza la ganancia de peso fue de 0.68% con un valor predictivo de 3330 g. Los niveles crecientes de espirulina no afectaron las medidas morfométricas de LV y AV a nivel de duodeno, yeyuno e íleon; en tanto, se obtuvieron respuestas lineal significativas en la PC y LV/PC en yeyuno y en LV/PC en íleon como respuesta a los niveles crecientes de espirulina en la dieta. Se concluye que los niveles crecientes de espirulina influyen sobre el rendimiento productivo en condiciones experimentales, mientras que no fueron concluyentes para la morfometría intestinal en pollos Cobb 500 a los 42 días de edad

    Neurons in the Nucleus papilio contribute to the control of eye movements during REM sleep

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    Rapid eye movements (REM) are characteristic of the eponymous phase of sleep, yet the underlying motor commands remain an enigma. Here, we identified a cluster of Calbindin-D28K-expressing neurons in the Nucleus papilio (NPCalb), located in the dorsal paragigantocellular nucleus, which are active during REM sleep and project to the three contralateral eye-muscle nuclei. The firing of opto-tagged NPCalb neurons is augmented prior to the onset of eye movements during REM sleep. Optogenetic activation of NPCalb neurons triggers eye movements selectively during REM sleep, while their genetic ablation or optogenetic silencing suppresses them. None of these perturbations led to a change in the duration of REM sleep episodes. Our study provides the first evidence for a brainstem premotor command contributing to the control of eye movements selectively during REM sleep in the mammalian brain

    ABJM Baryon Stability and Myers effect

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    We consider magnetically charged baryon vertex like configurations in AdS^4 X CP^3 with a reduced number of quarks l. We show that these configurations are solutions to the classical equations of motion and are stable beyond a critical value of l. Given that the magnetic flux dissolves D0-brane charge it is possible to give a microscopical description in terms of D0-branes expanding into fuzzy CP^n spaces by Myers dielectric effect. Using this description we are able to explore the region of finite 't Hooft coupling.Comment: 29 pages, Latex; minor changes; version to appear in JHE

    Non-singlet Baryons in Less Supersymmetric Backgrounds

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    We analyze the holographic description of non-singlet baryons in various backgrounds with reduced supersymmetries and/or confinement. We show that they exist in all AdS_5xY_5 backgrounds with Y_5 an Einstein manifold bearing five form flux, for a number of quarks 5N/8< k< N, independently on the supersymmetries preserved. This result still holds for gamma_i deformations. In the confining Maldacena-Nunez background non-singlet baryons also exist, although in this case the interval for the number of quarks is reduced as compared to the conformal case. We generalize these configurations to include a non-vanishing magnetic flux such that a complementary microscopical description can be given in terms of lower dimensional branes expanding into fuzzy baryons. This description is a first step towards exploring the finite 't Hooft coupling region.Comment: 36 Pages, 1 figure, Latex, v2: few minor changes, JHEP versio

    Validation of techniques to mitigate copper surface contamination in CUORE

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    In this article we describe the background challenges for the CUORE experiment posed by surface contamination of inert detector materials such as copper, and present three techniques explored to mitigate these backgrounds. Using data from a dedicated test apparatus constructed to validate and compare these techniques we demonstrate that copper surface contamination levels better than 10E-07 - 10E-08 Bq/cm2 are achieved for 238U and 232Th. If these levels are reproduced in the final CUORE apparatus the projected 90% C.L. upper limit on the number of background counts in the region of interest is 0.02-0.03 counts/keV/kg/y depending on the adopted mitigation technique.Comment: 10 pages, 6 figures, 6 table

    Search for 14.4 keV solar axions from M1 transition of Fe-57 with CUORE crystals

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    We report the results of a search for axions from the 14.4 keV M1 transition from Fe-57 in the core of the sun using the axio-electric effect in TeO2 bolometers. The detectors are 5x5x5 cm3 crystals operated at about 10 mK in a facility used to test bolometers for the CUORE experiment at the Laboratori Nazionali del Gran Sasso in Italy. An analysis of 43.65 kg d of data was made using a newly developed low energy trigger which was optimized to reduce the detectors energy threshold. An upper limit of 0.63 c kg-1 d-1 was established at 95% C.L.. From this value, a lower bound at 95% C.L. was placed on the Peccei-Quinn energy scale of fa >= 0.76 10**6 GeV for a value of S=0.55 for the flavor-singlet axial vector matrix element. Bounds are given for the interval 0.15 < S < 0.55.Comment: 14 pages, 6 figures, submitted to JCA

    Search for the rare decays B0J/ψγB^{0}\to J/\psi \gamma and Bs0J/ψγB^{0}_{s} \to J/\psi \gamma

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    A search for the rare decay of a B0B^{0} or Bs0B^{0}_{s} meson into the final state J/ψγJ/\psi\gamma is performed, using data collected by the LHCb experiment in pppp collisions at s=7\sqrt{s}=7 and 88 TeV, corresponding to an integrated luminosity of 3 fb1^{-1}. The observed number of signal candidates is consistent with a background-only hypothesis. Branching fraction values larger than 1.7×1061.7\times 10^{-6} for the B0J/ψγB^{0}\to J/\psi\gamma decay mode are excluded at 90% confidence level. For the Bs0J/ψγB^{0}_{s}\to J/\psi\gamma decay mode, branching fraction values larger than 7.4×1067.4\times 10^{-6} are excluded at 90% confidence level, this is the first branching fraction limit for this decay.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-044.htm

    The genomes of two key bumblebee species with primitive eusocial organization

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    Background: The shift from solitary to social behavior is one of the major evolutionary transitions. Primitively eusocial bumblebees are uniquely placed to illuminate the evolution of highly eusocial insect societies. Bumblebees are also invaluable natural and agricultural pollinators, and there is widespread concern over recent population declines in some species. High-quality genomic data will inform key aspects of bumblebee biology, including susceptibility to implicated population viability threats. Results: We report the high quality draft genome sequences of Bombus terrestris and Bombus impatiens, two ecologically dominant bumblebees and widely utilized study species. Comparing these new genomes to those of the highly eusocial honeybee Apis mellifera and other Hymenoptera, we identify deeply conserved similarities, as well as novelties key to the biology of these organisms. Some honeybee genome features thought to underpin advanced eusociality are also present in bumblebees, indicating an earlier evolution in the bee lineage. Xenobiotic detoxification and immune genes are similarly depauperate in bumblebees and honeybees, and multiple categories of genes linked to social organization, including development and behavior, show high conservation. Key differences identified include a bias in bumblebee chemoreception towards gustation from olfaction, and striking differences in microRNAs, potentially responsible for gene regulation underlying social and other traits. Conclusions: These two bumblebee genomes provide a foundation for post-genomic research on these key pollinators and insect societies. Overall, gene repertoires suggest that the route to advanced eusociality in bees was mediated by many small changes in many genes and processes, and not by notable expansion or depauperation

    Charge separation relative to the reaction plane in Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm NN}}= 2.76 TeV

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    Measurements of charge dependent azimuthal correlations with the ALICE detector at the LHC are reported for Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm NN}} = 2.76 TeV. Two- and three-particle charge-dependent azimuthal correlations in the pseudo-rapidity range η<0.8|\eta| < 0.8 are presented as a function of the collision centrality, particle separation in pseudo-rapidity, and transverse momentum. A clear signal compatible with a charge-dependent separation relative to the reaction plane is observed, which shows little or no collision energy dependence when compared to measurements at RHIC energies. This provides a new insight for understanding the nature of the charge dependent azimuthal correlations observed at RHIC and LHC energies.Comment: 12 pages, 3 captioned figures, authors from page 2 to 6, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/286

    A note on comonotonicity and positivity of the control components of decoupled quadratic FBSDE

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    In this small note we are concerned with the solution of Forward-Backward Stochastic Differential Equations (FBSDE) with drivers that grow quadratically in the control component (quadratic growth FBSDE or qgFBSDE). The main theorem is a comparison result that allows comparing componentwise the signs of the control processes of two different qgFBSDE. As a byproduct one obtains conditions that allow establishing the positivity of the control process.Comment: accepted for publicatio
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