112 research outputs found

    Efecto de la inclusión dietaria de glicerina sobre el desempeño productivo de conejos en crecimiento.

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     The possibility of using crude glycerine as a rabbit feed supplement is unknown in our country, therefore, this experiment was carried out in order to evaluate the effect of glycerin inclusion in the diet on growing rabbits performance. Thirty six White New Zealand weaned rabbits (18 male and 18 female) 35 d age (1008.61 ± 16.24 g initial BW) were assigned randomly to one of three treatments: A control diet and two levels of high purity glycerin (99%) inclusion (10 and 15%) in the diet; in a complete blocks experimental design with sub-sampling. No significant differences were observed in BW (P > 0.05) as a result of experimental diets. General means of daily weight gain were: 27.83, 26.71 and 23.38 g for T1, T2 and T3 treatments respectively, however differences between daily weight gains were not significant (P > 0.05). Calculated feed intake and feed conversion ratio were not affected by dietary treatments like the carcass yield (P > 0.05). Our results suggest that glycerin could be an appropiate energy source for growing rabbits diets at levels used in this experiment.La posibilidad de utilizar glicerina como fuente de energía en dietas para conejos en crecimiento no se ha evaluado en nuestro medio, por consiguiente se realizó un experimento para evaluar el efecto de la inclusión de glicerina en la ración sobre el desempeño productivo de conejos en crecimiento. Se utilizaron 36 conejos (18 hembras y 18 machos) destetos de raza Nueva Zelanda . Blanco, de 35 días de edad, con un peso inicial de 1008.61 ± 16.24 g, los cuales se sometieron a tres tratamientos: Una dieta control y dos tratamientos correspondientes a dos niveles de inclusión (10 y 15% en base seca) de glicerina de alta pureza (99%). Los animales fueron asignados aleatoriamente a los tratamientos en un diseño de bloques completos al azar con submuestreo. No se obtuvieron diferencias significativas (P > 0.05) en peso vivo por efecto de las dietas experimentales. El promedio general de ganancia diaria de peso fue de 26 g y no se observaron diferencias significativas entre tratamientos (P > 0.05). Tampoco se obtuvieron diferencias significativas (P > 0.05) por efecto de las dietas experimentales en el consumo estimado de alimento, conversión alimenticia estimada y rendimiento en canal (P > 0.05). Los resultados sugieren que la glicerina podría ser un ingrediente útil como fuente energética en raciones para conejos de engorde a los niveles de inclusión utilizados en el presente trabajo. &nbsp

    Fundamental Strings, Holography, and Nonlinear Superconformal Algebras

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    We discuss aspects of holography in the AdS_3 \times S^p near string geometry of a collection of straight fundamental heterotic strings. We use anomalies and symmetries to determine general features of the dual CFT. The symmetries suggest the appearance of nonlinear superconformal algebras, and we show how these arise in the framework of holographic renormalization methods. The nonlinear algebras imply intricate formulas for the central charge, and we show that in the bulk these correspond to an infinite series of quantum gravity corrections. We also makes some comments on the worldsheet sigma-model for strings on AdS_3\times S^2, which is the holographic dual geometry of parallel heterotic strings in five dimensions.Comment: 25 page

    Tear fluid biomarkers in ocular and systemic disease: potential use for predictive, preventive and personalised medicine

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    In the field of predictive, preventive and personalised medicine, researchers are keen to identify novel and reliable ways to predict and diagnose disease, as well as to monitor patient response to therapeutic agents. In the last decade alone, the sensitivity of profiling technologies has undergone huge improvements in detection sensitivity, thus allowing quantification of minute samples, for example body fluids that were previously difficult to assay. As a consequence, there has been a huge increase in tear fluid investigation, predominantly in the field of ocular surface disease. As tears are a more accessible and less complex body fluid (than serum or plasma) and sampling is much less invasive, research is starting to focus on how disease processes affect the proteomic, lipidomic and metabolomic composition of the tear film. By determining compositional changes to tear profiles, crucial pathways in disease progression may be identified, allowing for more predictive and personalised therapy of the individual. This article will provide an overview of the various putative tear fluid biomarkers that have been identified to date, ranging from ocular surface disease and retinopathies to cancer and multiple sclerosis. Putative tear fluid biomarkers of ocular disorders, as well as the more recent field of systemic disease biomarkers, will be shown

    Photodisintegration of 4^4He into p+t

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    The two-body photodisintegration of 4^4He into a proton and a triton has been studied using the CEBAF Large-Acceptance Spectrometer (CLAS) at Jefferson Laboratory. Real photons produced with the Hall-B bremsstrahlung-tagging system in the energy range from 0.35 to 1.55 GeV were incident on a liquid 4^4He target. This is the first measurement of the photodisintegration of 4^4He above 0.4 GeV. The differential cross sections for the γ\gamma4^4Hept\to pt reaction have been measured as a function of photon-beam energy and proton-scattering angle, and are compared with the latest model calculations by J.-M. Laget. At 0.6-1.2 GeV, our data are in good agreement only with the calculations that include three-body mechanisms, thus confirming their importance. These results reinforce the conclusion of our previous study of the three-body breakup of 3^3He that demonstrated the great importance of three-body mechanisms in the energy region 0.5-0.8 GeV .Comment: 13 pages submitted in one tgz file containing 2 tex file and 22 postscrip figure

    Exclusive ρ0\rho^0 electroproduction on the proton at CLAS

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    The epepρ0e p\to e^\prime p \rho^0 reaction has been measured, using the 5.754 GeV electron beam of Jefferson Lab and the CLAS detector. This represents the largest ever set of data for this reaction in the valence region. Integrated and differential cross sections are presented. The WW, Q2Q^2 and tt dependences of the cross section are compared to theoretical calculations based on tt-channel meson-exchange Regge theory on the one hand and on quark handbag diagrams related to Generalized Parton Distributions (GPDs) on the other hand. The Regge approach can describe at the \approx 30% level most of the features of the present data while the two GPD calculations that are presented in this article which succesfully reproduce the high energy data strongly underestimate the present data. The question is then raised whether this discrepancy originates from an incomplete or inexact way of modelling the GPDs or the associated hard scattering amplitude or whether the GPD formalism is simply inapplicable in this region due to higher-twists contributions, incalculable at present.Comment: 29 pages, 29 figure

    Differential cross sections and spin density matrix elements for the reaction gamma p -> p omega

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    High-statistics differential cross sections and spin density matrix elements for the reaction gamma p -> p omega have been measured using the CLAS at Jefferson Lab for center-of-mass (CM) energies from threshold up to 2.84 GeV. Results are reported in 112 10-MeV wide CM energy bins, each subdivided into cos(theta_CM) bins of width 0.1. These are the most precise and extensive omega photoproduction measurements to date. A number of prominent structures are clearly present in the data. Many of these have not previously been observed due to limited statistics in earlier measurements

    First Measurement of Beam-Recoil Observables Cx and Cz in Hyperon Photoproduction

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    Spin transfer from circularly polarized real photons to recoiling hyperons has been measured for the reactions γ+pK++Λ\vec\gamma + p \to K^+ + \vec\Lambda and γ+pK++Σ0\vec\gamma + p \to K^+ + \vec\Sigma^0. The data were obtained using the CLAS detector at Jefferson Lab for center-of-mass energies WW between 1.6 and 2.53 GeV, and for 0.85<cosθK+c.m.<+0.95-0.85<\cos\theta_{K^+}^{c.m.}< +0.95. For the Λ\Lambda, the polarization transfer coefficient along the photon momentum axis, CzC_z, was found to be near unity for a wide range of energy and kaon production angles. The associated transverse polarization coefficient, CxC_x, is smaller than CzC_z by a roughly constant difference of unity. Most significantly, the {\it total} Λ\Lambda polarization vector, including the induced polarization PP, has magnitude consistent with unity at all measured energies and production angles when the beam is fully polarized. For the Σ0\Sigma^0 this simple phenomenology does not hold. All existing hadrodynamic models are in poor agreement with these results.Comment: 28 pages, 18 figures, Submitted to Physical Review

    Functionalization of Carbon Nanomaterial Surface by Doxorubicin and Antibodies to Tumor Markers

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    The actual task of oncology is effective treatment of cancer while causing a minimum harm to the patient. The appearance of polymer nanomaterials and technologies launched new applications and approaches of delivery and release of anticancer drugs. The goal of work was to test ultra dispersed diamonds (UDDs) and onion-like carbon (OLCs) as new vehicles for delivery of antitumor drug (doxorubicin (DOX)) and specific antibodies to tumor receptors. Stable compounds of UDDs and OLCs with DOX were obtained. As results of work, an effectiveness of functionalization was 2.94 % w/w for OLC-DOX and 2.98 % w/w for UDD-DOX. Also, there was demonstrated that UDD-DOX and OLC-DOX constructs had dose-dependent cytotoxic effect on tumor cells in the presence of trypsin. The survival of adenocarcinoma cells reduced from 52 to 28 % in case of incubation with the UDD-DOX in concentrations from 8.4–2.5 to 670–20 μg/ml and from 72 to 30 % after incubation with OLC-DOX. Simultaneously, antibodies to epidermal growth factor maintained 75 % of the functional activity and specificity after matrix-assisted pulsed laser evaporation deposition. Thus, the conclusion has been made about the prospects of selected new methods and approaches for creating an antitumor agent with capabilities targeted delivery of drugs

    A measurement of the differential cross section for the reaction γnπp\gamma n \to \pi^{-} p from deuterium

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    We report a measurement of the differential cross section for the γnπp\gamma n \to \pi^- p process from the CLAS detector at Jefferson Lab in Hall B for photon energies between 1.0 and 3.5 GeV and pion center-of-mass (c.m.) angles (θc.m.\theta_{c.m.}) between 50^\circ and 115^\circ. We confirm a previous indication of a broad enhancement around a c.m. energy (s\sqrt{s}) of 2.2 GeV at θc.m.=90\theta_{c.m.}=90^\circ in the scaled differential cross section, s7dσdts^7 {\frac{d\sigma}{dt}}. Our data show the angular dependence of this enhancement as the scaling region is approached in the kinematic region from 70^\circ to 105^\circ.Comment: 6 pages, 3 figures. submitted to PR
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