Caracterización estructural del sistema ovino-caprino de la región noroeste de República Dominicana (Structural characterization of sheep and goat farming systems in Northwest Dominican Republic)

The aim of this study was to analyze structural aspects of goat and ovine livestock farming systems located in the Norwest of Dominican Republic. The sample (94 farms) was randomly selected with proportional allocation by region. Forty-four variables related to structural and productive aspects were analyzed. The average size of farms was 96 ha and 165 animals. Their facilities are simple, nonspecific and barely functional, with a mean of 2 pens per farm. Farms generally do not have perimeter fences, facilities for breeding, feeding or watering points. The reproductive strategy is the natural breeding throughout the year on most farms, with a ratio of one sire for every 36 females, and there are no breeding records. The first mating takes place with an average weight of 17 kg at 6.5 months of age. Feeding is based on grazing of natural pastures and forests (94%), reaching a stocking density of 0.83 LU/ha. Food supplementation is used in 37% of farms, mainly in sheep and mixed farms. The lambs and goats are sold when they reach 23 kg in weight, around 7 months of age. The farms do not receive technical advice, although 94% of them apply preventive treatments on a regular basis. The mortality rate reached 12%. In general, farms are very heterogeneous in their production structure, management, nutrition and health. Thus, a group of farms developed a traditional system (goats), while the most efficient and technified correspond to sheep and mixed farms

Antimonene-modified screen-printed carbon nanofibers electrode for enhanced electroanalytical response of metal ions.

A two-dimensional (2D) Sb-modified screen-printed carbon nanofibers electrode (2D Sbexf-SPCNFE) was developed to improve the stripping voltammetric determination of Cd(II) and Pb(II), taking advantage of the synergistic effect between the two nanomaterials. The surface morphology of the 2D Sbexf-SPCNFE was investigated by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and Raman spectroscopy. The analytical performance of 2D Sbexf-SPCNFE was compared to those presented by screen-printed carbon electrodes modified with 2D Sbexf (2D Sbexf-SPCE) and the corresponding bare electrodes: screen-printed carbon nanofibers electrode (SPCNFEbare) and screen-printed carbon electrode (SPCEbare). After optimizing the experimental conditions, the 2D Sbexf-SPCNFE exhibited much better analytical parameters compared to the other assessed sensors. Analysis in 0.01 mol L−1 HCl (pH = 2) using 2D Sbexf-SPCNFE showed excellent linear behavior in the concentration range of 2.9 to 85.0 µg L−1 and 0.3 to 82.0 µg L−1 for Cd(II) and Pb(II), respectively. The limits of detection after 240 s deposition time for Cd(II) and Pb(II) were 0.9 and 0.1 µg L−1, and sensitivities between 1.5 and 3 times higher than those displayed by SPCEbare, SPCNFEbare, and 2D Sbexf-SPCE were obtained. Finally, the 2D Sbexf-SPCNFE was successfully applied to the determination of Cd(II) and Pb(II) traces in a certified estuarine water sample

Effect of Activated Carbon Made from Cocoa (Theobroma Cacao L.) Shells on the Adsorption of Iron in Aquifer Water

This research aims to determine the effect of activated carbon obtained from cocoa husks (Theobroma cacao L.) on the adsorption of iron (II) present in water of an aquifer for human consumption. Charcoal was prepared at different carbonization temperatures (500, 600 and 700 °C) for 30 minutes and activated with phosphoric acid in the proportions of 1:1. Iron (II) adsorption was determined as a function of variations in mixing speed, contact time, charcoal dosage and stirring speed. It was determined that, over the range considered, agitation speeds had no significant effect on the percentage of iron (II) removal, being the dose of activated carbon and temperature, the most influential variables. The water samples had an initial iron concentration of 3.15 mg/L and 4 mg/L. The best iron (II) adsorption result was obtained with activated carbon at the carbonization temperature of 700 °C, with a mass of 1.5 g of carbon, with efficiencies of 93 % and 98 % for both samples considered. Based on the results, it was concluded water for human consumption is treatable with activated carbon derived from Theobroma cacao L. for the adsorption of iron (II), considering that this parameter is below the maximum limit of 0.3 mg/L allowed by current regulations

Astroclimate at San Pedro M\'artir I: 2004-2008 Seeing Statistics from the TMT Site Testing Data

We present comprehensive seeing statistics for the San Pedro M\'artir site derived from the Thirty Meter Telescope site selection data. The observations were obtained between 2004 and 2008 with a Differential Image Motion Monitor (DIMM) and a Multi Aperture Scintillation Sensor (MASS) combined instrument (MASS--DIMM). The parameters that are statistically analised here are: whole atmosphere seeing -measured by the DIMM-; free atmosphere seeing --measured by the MASS--; and ground-layer seeing (GL) --difference between the total and free-atmosphere seeing--. We made a careful data coverage study along with statistical distributions of simultaneous MASS--DIMM seeing measurements, in order to investigate the nightly, monthly, seasonal, annual and global behaviour, as well as possible hourly seeing trends. Although this campaign covers five years, the sampling is uneven, being 2006 and 2007 the best sampled years in terms of seasonal coverage. The overall results yield a median seeing of 0.78 (DIMM), 0.37 (MASS) and 0.59 arcsec (GL). The strongest contribution to the whole atmosphere seeing comes, therefore, from a strong ground layer. We find that the best season is summer, while the worst one is winter, in accordance with previous studies. It is worth noting that the best yearly results are correlated with the best sampled years. The hourly analysis shows that there is no statistically significant tendency of seeing degradation towards dawn. The seeing values are slightly larger than those reported before. This may be caused by climate changes.Comment: Accepted for publication (2012 June 14) in MNRAS, 15 pages, 16 Figures, 8 Table

The histone deacetylase inhibitor valproic acid attenuates phospholipase Cγ2 and IgE-mediated mast cell activation.

Mast cell activation through the high-affinity IgE receptor (FcεRI) plays a central role in allergic reactions. FcεRI-mediated activation triggers multiple signaling pathways leading to degranulation and synthesis of different inflammatory mediators. IgE-mediated mast cell activation can be modulated by different molecules, including several drugs. Herein, we investigated the immunomodulatory activity of the histone deacetylase inhibitor valproic acid (VPA) on IgE-mediated mast cell activation. To this end, bone marrow-derived mast cells (BMMC) were sensitized with IgE and treated with VPA followed by FcεRI cross-linking. The results indicated that VPA reduced mast cell IgE-dependent degranulation and cytokine release. VPA also induced a significant reduction in the cell surface expression of FcεRI and CD117, but not other mast cell surface molecules. Interestingly, VPA treatment inhibited the phosphorylation of PLCγ2, a key signaling molecule involved in IgE-mediated degranulation and cytokine secretion. However, VPA did not affect the phosphorylation of other key components of the FcεRI signaling pathway, such as Syk, Akt, ERK1/2, or p38. Altogether, our data demonstrate that VPA affects PLCγ2 phosphorylation, which in turn decreases IgE-mediated mast cell activation. These results suggest that VPA might be a key modulator of allergic reactions and might be a promising therapeutic candidate

Regeneración de oreomunnea mexicana (Juglandaceae), una especie relicto, amenazada del bosque de niebla de sierra juárez, oaxaca, México

Oreomunnea mexicana (Stand.) J.F. Leroy is a relict species, threatened and a key species for cloud ecosystem functionof the Sierra Juárez, Oaxaca, the most extensive and best conserved in Mexico. This study includes a diagnostic on two critical stages of the process of population regeneration of O. mexicana. To this end, it analyzed the: 1) production, dispersion, viability and germination of seeds, 2) effect of predation on the growth and survival of the seedlings, and 3) effect of environmental variables (soil, canopy structure and solar radiation) on the regeneration of the species. The study was made from 2014 to 2015 in the cloud forest of Santiago Comaltepec, Oaxaca, Mexico, in two locations (San Bernardo and El Orquidiario). Differences in seed production were found between years and between locations, as well as low seed viability and a high percentage of seed parasitism. The establishment and growth of the seedlings are subject to find suitable microhabitats, since seedlings have specific illumination and soil requirements. The high edaphic specificity faced by the species could be a key factor for its fragmented and discontinuous distribution in Sierra Juárez. Further population regeneration studies are recommended to increase knowledge of the species and thereby achieve its conservation. © 2019, Instituto de Ecologia, A.C. All rights reserved

Multiplicity dependence of jet-like two-particle correlations in p-Pb collisions at sNN\sqrt{s_{NN}} = 5.02 TeV

Two-particle angular correlations between unidentified charged trigger and associated particles are measured by the ALICE detector in p-Pb collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV. The transverse-momentum range 0.7 $< p_{\rm{T}, assoc} < p_{\rm{T}, trig} <$ 5.0 GeV/$c$ is examined, to include correlations induced by jets originating from low momen\-tum-transfer scatterings (minijets). The correlations expressed as associated yield per trigger particle are obtained in the pseudorapidity range $|\eta|<0.9$. The near-side long-range pseudorapidity correlations observed in high-multiplicity p-Pb collisions are subtracted from both near-side short-range and away-side correlations in order to remove the non-jet-like components. The yields in the jet-like peaks are found to be invariant with event multiplicity with the exception of events with low multiplicity. This invariance is consistent with the particles being produced via the incoherent fragmentation of multiple parton--parton scatterings, while the yield related to the previously observed ridge structures is not jet-related. The number of uncorrelated sources of particle production is found to increase linearly with multiplicity, suggesting no saturation of the number of multi-parton interactions even in the highest multiplicity p-Pb collisions. Further, the number scales in the intermediate multiplicity region with the number of binary nucleon-nucleon collisions estimated with a Glauber Monte-Carlo simulation.Comment: 23 pages, 6 captioned figures, 1 table, authors from page 17, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/161