Influencia del tiempo de maduración en la calidad nutricional de ensilajes con forrajes arbóreos

This work was conducted at the Universidad de los Llanos located on the Barcelona hamlet, Meta Department, Colombia. In this investigation was evaluated the nutritional quality of silages prepared with forage trees: Cratylia argentea, Hibiscus rosa-sinensis, Trychanthera gigantea and Tithonia diversifolia. The species were sown in plots, and then made a pruning and were harvested 60 days after which leaves were kept silages 5 kg, leaving four periods of maturation (0, 30, 60, 90 days). The silage was analyzed in the Laboratory of Animal Nutrition: dry matter (DM), ash, fat, protein, crude fiber (CF), neutral detergent fiber (NDF), acid detergent fiber (ADF), nitrogen joined FDN (NFDN), cellulose, and lignin. Cratylia, argentea (32.6%) was produced more dry matter than Tithonia diversifolia (30%), Hibiscus rosa-sinensis (28.5%) and Trychanthera gigantea (25%). Although there was an increase of DM with increasing the retention period of silage (0, 30, 60 and 90) as increases FDN, FDA and lignin in these four forage species too. The protein in the four species decreased with longer maturity of these forage silage, this reduction was greater in Cratylia argentea (8.2%) compared with others: Hibiscus rosa-sinensis (6%), Trychanthera gigantea (6%) and Tithonia diversifolia (4%).Este trabajo se realizó en la Universidad de los Llanos ubicada en el Km 12 vía Puerto López en la Vereda Barcelona, Departamento Meta, Colombia. Se evaluó la calidad nutricional de ensilajes de cuatro especies forrajeras preparados con las siguientes especies: veranera (Cratylia argéntea), Cayeno (Hibiscus-rosa-sinensis) nacedero (Trychanthera gigantea) y Botón de oro (Titonia diversifolia). Las especies se sembraron en parcelas, y después se realizó una poda y 60 días después se cosecharon sus hojas las cuales fueron conservadas en microsilos de 5 kilogramos, dejando cuatro periodos de maduración (0, 30, 60, 90 días). Los ensilajes fueron analizados en el Laboratorio de Nutrición Animal: materia seca (MS), cenizas, grasa, proteína, fibra cruda (FC), fibra detergente neutro (FDN), fibra detergente ácido (FDA), nitrógeno adherido a FDN (NFDN), celulosa, y lignina. La especie que más materia seca produjo fue la veranera 32.6% seguida de botón de oro (30%), cayeno (28,5%) nacedero (25%). Aunque se observó un aumento de la MS a medida que aumentaba el tiempo de maduración del ensilaje (0, 30, 60 y 90). También se mostraron incrementos a medida que el forraje maduraba la FDN, FDA y la lignina en estas cuatro especies forrajeras. El porcentaje de proteína en las cuatro especies decreció con mayor tiempo de maduración del ensilaje de estas forrajeras, esta reducción fue mayor en la veranera (8.2%) en comparación con las demás: cayeno (6%), cajeto (6%) y botón de oro (4%)

Renormalized Surface Charge Density for a Strongly Charged Plate in Asymmetric Electrolytes: Asymptotic Exact Results in Poisson Boltzmann Theory

The Poisson-Boltzmann equation for a strongly charged plate inside a generic charge-asymmetric electrolyte is solved using the method of asymptotic matching. Both near field and far field asymptotic behaviors of the potential are systematically analyzed. Using these expansions, the renormalized surface charge density is obtained as an asymptotic series in terms of the bare surface charge density.Comment: 11 pages, 4 eps figure

Assessment of penetration of Ascorbyl Tetraisopalmitate into biological membranes by molecular dynamics

The present work, involves the simulation of the transport of a vitamin C derivative, Ascorbyl Tetraisopalmitate (ATI), through human skin by molecular dynamics. Percutaneous absorption of the ATI molecule through the infundibulum, an important route of absorption into the hair follicle of the human skin, has been modeled and compared with the stratum corneum membrane. The comparative study was done, using molecular dynamics with Martini force field. In infundibulum, a single ATI molecule require more time to penetrate, and the data obtained suggested that a high concentration of ATI molecule accelerated the process of penetration. In conclusion, the ATI molecule was found to have more affinity towards the stratum corneum as compared towards the infundibulum and it followed a straight pathway to penetrate (until 600 ns of simulation). In infundibulum, it showed less affinity, more mobility and followed a lateral pathway. Thus, this work contributes to a better understanding of the different molecular interactions during percutaneous absorption of active molecules in these two different types of biological membranes.The authors acknowledge financial support from the Brazilian agencies CAPES, Finep and Fapesp (Project FINEP 01.10.0661-00, FAPESP 2011/13250-0, FAPESP 2013/17247-9, FAPESP 2014/05975-2, CAPES 88887068264/2014-00), of Institute of Research and Development, University of Vale Paraíba

Diagnóstico de la comunicación rural en Colombia.

El objetivo es conocer el estado actual de la investigación realizada en el país sobre comunicación rural y las necesidades de investigación para transferencia de tecnología agropecuaria según los agentes de cambio del ICA. El trabajo se inició con la conformación de un grupo multidisciplinario integrado por funcionarios del ICA, profesionales en agronomía, medicina veterinaria, comunicación social y economía del hogar. Se recolectaron 171 investigaciones sobre comunicación rural de las cuales se eliminaron 43 debido a que no encajaban dentro de los criterios establecidos para el análisis, haciéndose sobre 128 trabajos. Con base en los resultados y discusión se presentan las siguientes conclusiones : Es poca la investigación sobre el análisis de la fuente o emisor en cuanto a sus actividades y capacidad para actuar como tal. En cuanto al mensaje no se observa una clara tendencia hacia el estudio del mismo. Existe muy poca investigación sobre formas y medios de comunicación individuales y de grupos, en contraste con los estudios sobre medios masivos. La mayoría de las investigaciones sobre medios han sido realizadas por ACPO. La investigación en comunicación se ha ocupado preferencialmente del pequeño agricultor, usuario atendido con asistencia técnica oficial. Los trabajos se han encaminado a determinar la adopción de prácticas, el planeamiento de la comunicación, el análisis interno e impacto de la comunicación. En la región Andina se concentra la mayor parte de los estudios. El ICA es la institución que ha realizado mayor número de investigaciones en comunicación rural principalmente, en las áreas cubiertas por sus Distritos de Transferencia de Tecnología, le siguen en su orden las universidades, el Programa de Estudios para Graduados UN-ICA y ACP

Anisotropic flow of charged hadrons, pions and (anti-)protons measured at high transverse momentum in Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm NN}}=2.76 TeV

The elliptic, $v_2$, triangular, $v_3$, and quadrangular, $v_4$, azimuthal anisotropic flow coefficients are measured for unidentified charged particles, pions and (anti-)protons in Pb-Pb collisions at $\sqrt{s_{\rm NN}} = 2.76$ TeV with the ALICE detector at the Large Hadron Collider. Results obtained with the event plane and four-particle cumulant methods are reported for the pseudo-rapidity range $|\eta|<0.8$ at different collision centralities and as a function of transverse momentum, $p_{\rm T}$, out to $p_{\rm T}=20$ GeV/$c$. The observed non-zero elliptic and triangular flow depends only weakly on transverse momentum for $p_{\rm T}>8$ GeV/$c$. The small $p_{\rm T}$ dependence of the difference between elliptic flow results obtained from the event plane and four-particle cumulant methods suggests a common origin of flow fluctuations up to $p_{\rm T}=8$ GeV/$c$. The magnitude of the (anti-)proton elliptic and triangular flow is larger than that of pions out to at least $p_{\rm T}=8$ GeV/$c$ indicating that the particle type dependence persists out to high $p_{\rm T}$.Comment: 16 pages, 5 captioned figures, authors from page 11, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/186

Centrality dependence of charged particle production at large transverse momentum in Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm{NN}}} = 2.76 TeV

The inclusive transverse momentum ($p_{\rm T}$) distributions of primary charged particles are measured in the pseudo-rapidity range $|\eta|<0.8$ as a function of event centrality in Pb-Pb collisions at $\sqrt{s_{\rm{NN}}}=2.76$ TeV with ALICE at the LHC. The data are presented in the $p_{\rm T}$ range $0.15<p_{\rm T}<50$ GeV/$c$ for nine centrality intervals from 70-80% to 0-5%. The Pb-Pb spectra are presented in terms of the nuclear modification factor $R_{\rm{AA}}$ using a pp reference spectrum measured at the same collision energy. We observe that the suppression of high-$p_{\rm T}$ particles strongly depends on event centrality. In central collisions (0-5%) the yield is most suppressed with $R_{\rm{AA}}\approx0.13$ at $p_{\rm T}=6$-7 GeV/$c$. Above $p_{\rm T}=7$ GeV/$c$, there is a significant rise in the nuclear modification factor, which reaches $R_{\rm{AA}} \approx0.4$ for $p_{\rm T}>30$ GeV/$c$. In peripheral collisions (70-80%), the suppression is weaker with $R_{\rm{AA}} \approx 0.7$ almost independently of $p_{\rm T}$. The measured nuclear modification factors are compared to other measurements and model calculations.Comment: 17 pages, 4 captioned figures, 2 tables, authors from page 12, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/284

Measurement of charm production at central rapidity in proton-proton collisions at s=2.76\sqrt{s} = 2.76 TeV

The $p_{\rm T}$-differential production cross sections of the prompt (B feed-down subtracted) charmed mesons D$^0$, D$^+$, and D$^{*+}$ in the rapidity range $|y|<0.5$, and for transverse momentum $1< p_{\rm T} <12$ GeV/$c$, were measured in proton-proton collisions at $\sqrt{s} = 2.76$ TeV with the ALICE detector at the Large Hadron Collider. The analysis exploited the hadronic decays D$^0 \rightarrow$K$\pi$, D$^+ \rightarrow$K$\pi\pi$, D$^{*+} \rightarrow$D$^0\pi$, and their charge conjugates, and was performed on a $L_{\rm int} = 1.1$ nb$^{-1}$ event sample collected in 2011 with a minimum-bias trigger. The total charm production cross section at $\sqrt{s} = 2.76$ TeV and at 7 TeV was evaluated by extrapolating to the full phase space the $p_{\rm T}$-differential production cross sections at $\sqrt{s} = 2.76$ TeV and our previous measurements at $\sqrt{s} = 7$ TeV. The results were compared to existing measurements and to perturbative-QCD calculations. The fraction of cdbar D mesons produced in a vector state was also determined.Comment: 20 pages, 5 captioned figures, 4 tables, authors from page 15, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/307

Inclusive J/psi production in pp collisions at sqrt(s) = 2.76 TeV

The ALICE Collaboration has measured inclusive J/psi production in pp collisions at a center of mass energy sqrt(s)=2.76 TeV at the LHC. The results presented in this Letter refer to the rapidity ranges |y|<0.9 and 2.5<y<4 and have been obtained by measuring the electron and muon pair decay channels, respectively. The integrated luminosities for the two channels are L^e_int=1.1 nb^-1 and L^mu_int=19.9 nb^-1, and the corresponding signal statistics are N_J/psi^e+e-=59 +/- 14 and N_J/psi^mu+mu-=1364 +/- 53. We present dsigma_J/psi/dy for the two rapidity regions under study and, for the forward-y range, d^2sigma_J/psi/dydp_t in the transverse momentum domain 0<p_t<8 GeV/c. The results are compared with previously published results at sqrt(s)=7 TeV and with theoretical calculations.Comment: 7 figures, 3 tables, accepted for publication in Phys. Lett.

Ks0^0_sKs0^0_s correlations in pp collisions at s=7\sqrt{s}=7 TeV from the LHC ALICE experiment

Identical neutral kaon pair correlations are measured in $\sqrt{s}=7$ TeV pp collisions in the ALICE experiment. One-dimensional K$^0_s$K$^0_s$ correlation functions in terms of the invariant momentum difference of kaon pairs are formed in two multiplicity and two transverse momentum ranges. The femtoscopic parameters for the radius and correlation strength of the kaon source are extracted. The f${\rm i}$t includes quantum statistics and final-state interactions of the a$_0$/f$_0$ resonance. K$^0_s$K$^0_s$ correlations show an increase in radius for increasing multiplicity and a slight decrease in radius for increasing transverse mass, $m_{\rm T}$, as seen in $\pi\pi$ correlations in the pp system and in heavy-ion collisions. Transverse mass scaling is observed between the K$^0_s$K$^0_s$ and $\pi\pi$ radii. Also, the f${\rm i}$rst observation is made of the decay of the f$_2'$(1525) meson into the K$^0_s$K$^0_s$ channel in pp collisions.Comment: 17 pages, 7 captioned figures, 2 tables, authors from page 12, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/310