Efecto de la edad y el nivel de vitamina E en dietas de pollos broiler sobre la modulación de la respuesta inmune.

La vitamina E pertenece al grupo de nutrientes con capacidad reguladora del sistema inmune (Koutsos y Klasing, 2008). En aves, la vitamina E induce cambios tanto en el sistema inmune innato como en el específico, mejora la función fagocítica de los macrófagos, amortigua la respuesta en fase aguda, disminuye la proporción de heterófilos y potencia la síntesis de anticuerpos (Koutsos y Klasing, 2008; Khan et al., 2012). Recientemente se ha demostrado que parte del efecto de la vitamina E está ligado a su capacidad de actuar directamente sobre factores de transcripción nuclear que modulan la expresión de citoquinas, tales como el factor-Kappa B o el PPAR γ (Koutsos y Klasing, 2008; Nakamura y Omaye, 2009). Por otro lado, el impacto de la vitamina E sobre la modulación del sistema inmune viene definido por factores tales como la edad y la relación dosis-respuesta. En broiler la inclusión en la dieta de niveles moderadamente superiores (25-50 UI/kg dieta) al recomendado por el National Research Council (NRC, 1994; 10 UI/kg) aumenta los títulos de anticuerpos tras la vacunación (Friedman et al., 1998; Leshchinsky y Klasing, 2001; Lin y Chang, 2006). Sin embargo, niveles superiores a 150 UI/kg tienen un efecto supresor sobre la producción de anticuerpos (Koutsos y Klasing, 2008). En relación a la edad es importante determinar aquellos periodos o “ventanas” en los que es necesario estimular el sistema inmune (Kogut, 2009). Un periodo a considerar sería el de las dos primeras semanas de vida del pollo debido a la menor funcionalidad de macrófagos y heterófilos (Kogut, 2009). El presente trabajo tiene como objetivo evaluar el efecto del nivel de Vitamina E y la edad sobre la modulación de la respuesta inmune en pollos. Para ello se estudió el efecto de la inclusión de 40 y 160 ppm de vitamina E en la dieta sobre la expresión de la interleuquina 2 (IL 2), el interferón gamma (IFN γ) y el factor de crecimiento mielomonocítico (MGF) en el bazo de los animales a los 7 y 21 días de edad

Anthropogenic ecosystem disturbance and the recovery debt

Ecosystem recovery from anthropogenic disturbances, either without human intervention or assisted by ecological restoration, is increasingly occurring worldwide. As ecosystems progress through recovery, it is important to estimate any resulting deficit in biodiversity and functions. Here we use data from 3,035 sampling plots worldwide, to quantify the interim reduction of biodiversity and functions occurring during the recovery process (that is, the 'recovery debt'). Compared with reference levels, recovering ecosystems run annual deficits of 46-51% for organism abundance, 27-33% for species diversity, 32-42% for carbon cycling and 31-41% for nitrogen cycling. Our results are consistent across biomes but not across degrading factors. Our results suggest that recovering and restored ecosystems have less abundance, diversity and cycling of carbon and nitrogen than 'undisturbed' ecosystems, and that even if complete recovery is reached, an interim recovery debt will accumulate. Under such circumstances, increasing the quantity of less-functional ecosystems through ecological restoration and offsetting are inadequate alternatives to ecosystem protection

Hemodynamic and metabolic effects of a new pediatric dobutamine formulation in hypoxic newborn pigs

Background: The aim of our study was to measure drug-related changes in hemodynamics and oxygen metabolism in response to different doses of an age-appropriate dobutamine formulation in hypoxic pigs. A secondary aim was to validate superior vena cava flow (SVCF) as a marker of cardiac index (CI) for subsequent clinical trials of this formulation in humans. Methods: Newborn pigs (n=18) were exposed to 2h-hypoxia (10-15% oxygen) followed by reoxygenation (21-30% oxygen 4h). After 1h-reoxygenation, pigs were randomized to: control group (no treatment), dobutamine infusion at a rate of 10-15μg/kg/min or 15-20μg/kg/min. Dobutamine groups received two dobutamine doses during 30min with a 60min washout period between doses. Cardiovascular profile and oxygen metabolism were monitored. In four animals an ultrasonic perivascular flow probe was placed around superior vena cava to measure SVCF. Results: Hypoxia significantly decreased CI, systemic-vascular-resistance and mean-arterial-bloodpressure (MABP). Dobutamine doses significantly increased heart-rate, CI and oxygen-delivery without changes in stroke-volume and MABP. Only 10-15μg/kg/min increased oxygen consumption and peripheral tissue oxygenation measured by Near-infrared-spectroscopy. A positive correlation was observed between SVCF and CI. Conclusion: The new pediatric dobutamine formulation improved hemodynamic status, with dose-specific differences in metabolic response. SVCF may be a useful surrogate for CI in subsequent clinical trials

Spontaneous alloying in binary metal microclusters - A molecular dynamics study -

Microcanonical molecular dynamics study of the spontaneous alloying(SA), which is a manifestation of fast atomic diffusion in a nano-sized metal cluster, is done in terms of a simple two dimensional binary Morse model. Important features observed by Yasuda and Mori are well reproduced in our simulation. The temperature dependence and size dependence of the SA phenomena are extensively explored by examining long time dynamics. The dominant role of negative heat of solution in completing the SA is also discussed. We point out that a presence of melting surface induces the diffusion of core atoms even if they are solid-like. In other words, the {\it surface melting} at substantially low temperature plays a key role in attaining the SA.Comment: 15 pages, 12 fgures, Submitted to Phys.Rev.

Duality and Universality for the Chern-Simons bosons

By mapping the relativistic version of the Chern-Simons-Landau-Ginzburg theory in 2+1 dimensions to the 3D lattice Villain x-y model coupled with the Chern-Simons gauge field, we investigate phase transitions of Chern-Simons bosons in the limit of strong coupling. We construct algebraically exact duality and flux attachment transformations of the lattice theories, corresponding to analogous transformations in the continuum limit. These transformations are used to convert the model with arbitrary fractional Chern-Simons coefficient $\alpha$ to a model with $\alpha$ either zero or one. Depending on this final value of $\alpha$, the phase transition in the original model is either in the universality class of the 3D x-y model or a ``fermionic'' universality class, unless the irrelevant corrections of cubic and higher power in momenta render the transition of the first order.Comment: 14 two-column pages, revtex 3.0, multicol and epsf.sty (optional), one PostScript figure, Submitted to Phys. Rev. B The changes intended to simplify the arguments and eliminate logical gaps. We also show how the filling factor $\nu$ is changed by the duality transformatio

Nanoinformatics: developing new computing applications for nanomedicine

Nanoinformatics has recently emerged to address the need of computing applications at the nano level. In this regard, the authors have participated in various initiatives to identify its concepts, foundations and challenges. While nanomaterials open up the possibility for developing new devices in many industrial and scientific areas, they also offer breakthrough perspectives for the prevention, diagnosis and treatment of diseases. In this paper, we analyze the different aspects of nanoinformatics and suggest five research topics to help catalyze new research and development in the area, particularly focused on nanomedicine. We also encompass the use of informatics to further the biological and clinical applications of basic research in nanoscience and nanotechnology, and the related concept of an extended ?nanotype? to coalesce information related to nanoparticles. We suggest how nanoinformatics could accelerate developments in nanomedicine, similarly to what happened with the Human Genome and other -omics projects, on issues like exchanging modeling and simulation methods and tools, linking toxicity information to clinical and personal databases or developing new approaches for scientific ontologies, among many others

Generalized cusp in AdS_4 x CP^3 and more one-loop results from semiclassical strings

We evaluate the exact one-loop partition function for fundamental strings whose world-surface ends on a cusp at the boundary of AdS_4 and has a "jump" in CP^3. This allows us to extract the stringy prediction for the ABJM generalized cusp anomalous dimension Gamma_{cusp}^{ABJM} (phi,theta) up to NLO in sigma-model perturbation theory. With a similar analysis, we present the exact partition functions for folded closed string solutions moving in the AdS_3 parts of AdS_4 x CP^3 and AdS_3 x S^3 x S^3 x S^1 backgrounds. Results are obtained applying to the string solutions relevant for the AdS_4/CFT_3 and AdS_3/CFT_2 correspondence the tools previously developed for their AdS_5 x S^5 counterparts.Comment: 48 pages, 2 figures, version 3, corrected misprints in formulas 2.12, B.86, C.33, added comment on verification of the light-like limi

On the nature of the galactic early-B hypergiants

Despite their importance to a number of astrophysical fields, the lifecycles of very massive stars are still poorly defined. In order to address this shortcoming, we present a detailed quantitative study of the physical properties of four early-B hypergiants (BHGs); Cyg OB2 #12, zeta Sco, HD190603 and BP Cru. These are combined with an analysis of their long-term spectroscopic and photometric behaviour in order to determine their evolutionary status. The long-term datasets revealed that they are remarkably stable over long periods (>40yr), with the possible exception of zeta Sco prior to the 20th century, in contrast to the typical excursions that characterise luminous blue variables (LBVs). Zeta Sco, HD190603 and BP Cru possess physical properties intermediate between B supergiants and LBVs; we therefore suggest that BHGs are the immediate descendants and progenitors (respectively) of such stars (for initial masses in the range ~30-60Msun). In contrast, while the wind properties of Cyg OB2 #12 are consistent with this hypothesis, the combination of extreme luminosity and spectroscopic mass (~110Msun) and comparatively low temperature means it cannot be accommodated in such a scheme. Likewise, despite its co-location with several LBVs above the Humphreys-Davidson (HD) limit, the lack of long term variability and its unevolved chemistry apparently excludes such an identification. Since such massive stars are not expected to evolve to such cool temperatures, the properties of Cyg OB2 #12 are difficult to understand under current evolutionary paradigms. [ABRIDGED]Comment: 36 pages, 19 figures (of which 17 pages are online supplemental material). Accepted for publication in Astronomy and Astrophysic

ATP5H/KCTD2 locus is associated with Alzheimer's disease risk

To identify loci associated with Alzheimer disease, we conducted a three-stage analysis using existing genome-wide association studies (GWAS) and genotyping in a new sample. In Stage I, all suggestive single-nucleotide polymorphisms (at P<0.001) in a previously reported GWAS of seven independent studies (8082 Alzheimer's disease (AD) cases; 12 040 controls) were selected, and in Stage II these were examined in an in silico analysis within the Cohorts for Heart and Aging Research in Genomic Epidemiology consortium GWAS (1367 cases and 12904 controls). Six novel signals reaching P<5 × 10-6 were genotyped in an independent Stage III sample (the Fundació ACE data set) of 2200 sporadic AD patients and 2301 controls. We identified a novel association with AD in the adenosine triphosphate (ATP) synthase, H+ transporting, mitochondrial F0 (ATP5H)/Potassium channel tetramerization domain-containing protein 2 (KCTD2) locus, which reached genome-wide significance in the combined discovery and genotyping sample (rs11870474, odds ratio (OR)=1.58, P=2.6 × 10 -7 in discovery and OR=1.43, P=0.004 in Fundació ACE data set; combined OR=1.53, P=4.7 × 10 -9). This ATP5H/KCTD2 locus has an important function in mitochondrial energy production and neuronal hyperpolarization during cellular stress conditions, such as hypoxia or glucose deprivation

Improved functionalization of oleic acid-coated iron oxide nanoparticles for biomedical applications

Superparamagnetic iron oxide nanoparticles can providemultiple benefits for biomedical applications in aqueous environments such asmagnetic separation or magnetic resonance imaging. To increase the colloidal stability and allow subsequent reactions, the introduction of hydrophilic functional groups onto the particles’ surface is essential. During this process, the original coating is exchanged by preferably covalently bonded ligands such as trialkoxysilanes. The duration of the silane exchange reaction, which commonly takes more than 24 h, is an important drawback for this approach. In this paper, we present a novel method, which introduces ultrasonication as an energy source to dramatically accelerate this process, resulting in high-quality waterdispersible nanoparticles around 10 nmin size. To prove the generic character, different functional groups were introduced on the surface including polyethylene glycol chains, carboxylic acid, amine, and thiol groups. Their colloidal stability in various aqueous buffer solutions as well as human plasma and serum was investigated to allow implementation in biomedical and sensing applications.status: publishe