896 research outputs found

    Reproductive management of the goat

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    Objective: To share technical aspects with specialists in animal reproduction and producers that could help to improve the reproductive capacity of caprine livestock. Design/Methodology/Approach: Scientific evidence and experience in the reproductive management of goats are the basis that sustains the information presented in this article. Results: The goat is widely distributed in Mexico; it is a species with seasonal reproductive activity, but of easy manipulation with hormonal and natural means. Presently there is a large variety of biotechnologies that can be applied in the production units, to potentiate the reproductive activity of the goat. Study Limitations/Implications: The lack of knowledge and the lack of consulting and technical training limit the productive and reproductive potential of goat breeding in Mexico. Findings/Conclusions: Knowledge of the reproductive physiology of the goat and understanding of the means available to manipulate it guarantees its reproduction at the time and in the conditions desired by the producer and the marke

    The performance of spherical wavelets to detect non-Gaussianity in the CMB sky

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    We investigate the performance of spherical wavelets in discriminating between standard inflationary models (Gaussian) and non-Gaussian models. For the later we consider small perturbations of the Gaussian model in which an artificially specified skewness or kurtosis is introduced through the Edgeworth expansion. By combining all the information present in all the wavelet scales with the Fisher discriminant, we find that the spherical Mexican Hat wavelets are clearly superior to the spherical Haar wavelets. The former can detect levels of the skewness and kurtosis of ~1% for 33' resolution, an order of magnitude smaller than the later. Also, as expected, both wavelets are better for discriminating between the models than the direct consideration of moments of the temperature maps. The introduction of instrumental white noise in the maps, S/N=1, does not change the main results of this paper.Comment: 12 pages, 7 figures, accepted by MNRAS with minor change

    Regional Genetic Structure in the Aquatic Macrophyte Ruppia cirrhosa Suggests Dispersal by Waterbirds

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    The evolutionary history of the genus Ruppia has been shaped by hybridization, polyploidisation and vicariance that have resulted in a problematic taxonomy. Recent studies provided insight into species circumscription, organelle takeover by hybridization, and revealed the importance of verifying species identification to avoid distorting effects of mixing different species, when estimating population connectivity. In the present study, we use microsatellite markers to determine population diversity and connectivity patterns in Ruppia cirrhosa including two spatial scales: (1) from the Atlantic Iberian coastline in Portugal to the Siculo-Tunisian Strait in Sicily and (2) within the Iberian Peninsula comprising the Atlantic-Mediterranean transition. The higher diversity in the Mediterranean Sea suggests that populations have had longer persistence there, suggesting a possible origin and/or refugial area for the species. The high genotypic diversities highlight the importance of sexual reproduction for survival and maintenance of populations. Results revealed a regional population structure matching a continent-island model, with strong genetic isolation and low gene flow between populations. This population structure could be maintained by waterbirds, acting as occasional dispersal vectors. This information elucidates ecological strategies of brackish plant species in coastal lagoons, suggesting mechanisms used by this species to colonize new isolated habitats and dominate brackish aquatic macrophyte systems, yet maintaining strong genetic structure suggestive of very low dispersal.Fundacao para a Cincia e Tecnologia (FCT, Portugal) [PTDC/MAR/119363/2010, BIODIVERSA/0004/2015, UID/Multi/04326/2013]Pew FoundationSENECA FoundationMurcia Government, Spain [11881/PI/09]FCT Investigator Programme-Career Development [IF/00998/2014]Spanish Ministry of Education [AP2008-01209]European Community [00399/2012]info:eu-repo/semantics/publishedVersio

    Study of the Very High Energy emission of M87 through its broadband spectral energy distribution

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    The radio galaxy M87 is the central dominant galaxy of the Virgo Cluster.Very High Energy (VHE,0.1\gtrsim 0.1 TeV) emission, from M87 has been detectedby Imaging Air Cherenkov Telescopes (IACTs ). Recently, marginal evidence forVHE long-term emission has also been observed by the High Altitude WaterCherenkov (HAWC) Observatory, a gamma ray and cosmic-ray detector array locatedin Puebla, Mexico. The mechanism that produces VHE emission in M87 remainsunclear. This emission is originated in its prominent jet, which has beenspatially resolved from radio to X-rays. In this paper, we constructed aspectral energy distribution from radio to gamma rays that is representative ofthe non-flaring activity of the source, and in order to explain the observedemission, we fit it with a lepto-hadronic emission model. We found that thismodel is able to explain non-flaring VHE emission of M87 as well as an orphanflare reported in 2005.<br

    Diversidad genética y distribución regional de cepas de Mycobacterium bovis del ganado en México

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    The molecular fingerprints of 878 isolates of Mycobacterium bovis from cattle, mostly dairy cattle, collected from cattle between 2009 and 2010 in different regions of Mexico were obtained by spoligotyping. Seventy-two percent (72 %) of the spoligotypes fell into nine clusters, and 27 % of the isolates fell into only two spoligotypes; 149 were orphan spoligotypes. The two predominant spoligotypes, arbitrarily designated as SP1 and SP2, were found in almost all States in Mexico, especially in central Mexico, where a concentration of dairy cattle is known. In spite of the wide distribution of spoligotypes observed, some show high regional preference, especially those in geographically distant regions. Only a few spoligotypes show patterns completely different from those shown by the most frequent spoligotypes, suggesting strange sources of infection or the formation of new genetic lines derived from non-lethal mutations. Most States with predominantly high dairy cattle populations showed similar spoligotypes, suggesting exchange of animals between regions. Some spoligotypes are common to dairy and beef cattle, suggesting transmission between populations, most probably due to the movement of dairy cattle to non-dairy regions.Se obtuvieron patrones moleculares (espoligotipos) de 878 aislados de Mycobacterium bovis de ganado de diferentes regiones de México entre los años 2009 y 2010. Setenta y dos por ciento (72 %) de los espoligotipos cayeron en nueve grupos y 27 % de los aislados dentro de sólo dos espoligotipos; 149 fueron espoligotipos individuales. Los dos espoligotipos predominantes, arbitrariamente identificados como SP1 y SP2, se distribuyen en la mayor parte del territorio nacional, en especial en la zona centro de México en ganado especializado en producción de leche. A pesar de la amplia distribución geográfica de los espoligotipos de mayor frecuencia, algunos muestran cierta localización, en especial los encontrados en zonas geográficas distantes, como es el caso de Chihuahua y Baja California. Aunque pocos, algunos espoligotipos muestran patrones moleculares distintos a los mostrados por los espoligotipos de mayor frecuencia, sugiriendo fuentes de infección desconocida. La mayoría de los Estados con ganadería predominantemente lechera muestran espoligotipos comunes, lo que sugiere intercambio regional frecuente de ganado. Algunos espoligotipos son comunes en ganado para leche y ganado para carne, lo que sugiere transmisión entre estas dos poblaciones; se desconoce, sin embargo, si los animales de carne infectados provienen de explotaciones extensivas o si son de engordas ubicadas dentro de la explotación lechera. Se propone la tipificación rutinaria de aislados de M. bovis obtenidos en todos los laboratorios de diagnóstico y mejorar la captura de información epidemiológica de los casos, para hacer mejores conclusiones epidemiológicas de la distribución espacial de las cepas de este agente en el territorio nacional

    The High-Altitude Water Cherenkov (HAWC) Observatory in M\'exico: The Primary Detector

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    The High-Altitude Water Cherenkov (HAWC) observatory is a second-generation continuously operated, wide field-of-view, TeV gamma-ray observatory. The HAWC observatory and its analysis techniques build on experience of the Milagro experiment in using ground-based water Cherenkov detectors for gamma-ray astronomy. HAWC is located on the Sierra Negra volcano in M\'exico at an elevation of 4100 meters above sea level. The completed HAWC observatory principal detector (HAWC) consists of 300 closely spaced water Cherenkov detectors, each equipped with four photomultiplier tubes to provide timing and charge information to reconstruct the extensive air shower energy and arrival direction. The HAWC observatory has been optimized to observe transient and steady emission from sources of gamma rays within an energy range from several hundred GeV to several hundred TeV. However, most of the air showers detected are initiated by cosmic rays, allowing studies of cosmic rays also to be performed. This paper describes the characteristics of the HAWC main array and its hardware.Comment: Accepted for publications in Nuclear Inst. and Methods in Physics Research, A (2023) 168253 ( https://www.sciencedirect.com/science/article/abs/pii/S0168900223002437 ); 39 pages, 14 Figure

    Gamma-ray Emission from Classical Nova V392 Per: Measurements from Fermi and HAWC

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    This paper reports on the γ\gamma-ray properties of the 2018 Galactic novaV392 Per, spanning photon energies \sim0.1 GeV to 100 TeV by combiningobservations from the Fermi Gamma-ray Space Telescope and the HAWC Observatory.In one of the most rapidly evolving γ\gamma-ray signals yet observed for anova, GeV γ\gamma rays with a power law spectrum with index Γ=2.0±0.1\Gamma = 2.0 \pm0.1 were detected over eight days following V392 Per's optical maximum. HAWCobservations constrain the TeV γ\gamma-ray signal during this time and alsobefore and after. We observe no statistically significant evidence of TeVγ\gamma-ray emission from V392 Per, but present flux limits. Tests of theextension of the Fermi/LAT spectrum to energies above 5 TeV are disfavored by 2standard deviations (95\%) or more. We fit V392 Per's GeV γ\gamma rays withhadronic acceleration models, incorporating optical observations, and comparethe calculations with HAWC limits.<br

    Validation of standardized data formats and tools for ground-level particle-based gamma-ray observatories

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    Ground-based gamma-ray astronomy is still a rather young field of research,with strong historical connections to particle physics. This is why mostobservations are conducted by experiments with proprietary data and analysissoftware, as it is usual in the particle physics field. However in recentyears, this paradigm has been slowly shifting towards the development and useof open-source data formats and tools, driven by upcoming observatories such asthe Cherenkov Telescope Array (CTA). In this context, a community-driven,shared data format (the gamma-astro-data-format or GADF) and analysis toolssuch as Gammapy and ctools have been developed. So far these efforts have beenled by the IACT community, leaving out other types of ground-based gamma-rayinstruments.We aim to show that the data from ground particle arrays, such asthe High-Altitude Water Cherenkov (HAWC) observatory, is also compatible withthe GADF and can thus be fully analysed using the related tools, in this caseGammapy. We reproduce several published HAWC results using Gammapy and dataproducts compliant with GADF standard. We also illustrate the capabilities ofthe shared format and tools by producing a joint fit of the Crab spectrumincluding data from six different gamma-ray experiments. We find excellentagreement with the reference results, a powerful check of both the publishedresults and the tools involved. The data from particle detector arrays such asthe HAWC observatory can be adapted to the GADF and thus analysed with Gammapy.A common data format and shared analysis tools allow multi-instrument jointanalysis and effective data sharing. Given the complementary nature of pointingand wide-field instruments, this synergy will be distinctly beneficial for thejoint scientific exploitation of future observatories such as the SouthernWide-field Gamma-ray Observatory and CTA.<br

    Searching for TeV Dark Matter in Irregular dwarf galaxies with HAWC Observatory

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    We present the results of dark matter (DM) searches in a sample of 31 dwarf irregular (dIrr) galaxies within the field of view of the HAWC Observatory. dIrr galaxies are DM dominated objects, which astrophysical gamma-ray emission is estimated to be negligible with respect to the secondary gamma-ray flux expected by annihilation or decay of Weakly Interacting Massive Particles (WIMPs). While we do not see any statistically significant DM signal in dIrr galaxies, we present the exclusion limits (95% C.L.95\%~\text{C.L.}) for annihilation cross-section and decay lifetime for WIMP candidates with masses between 11 and 100 TeV100~\text{TeV}. Exclusion limits from dIrr galaxies are relevant and complementary to benchmark dwarf Spheroidal (dSph) galaxies. In fact, dIrr galaxies are targets kinematically different from benchmark dSph, preserving the footprints of different evolution histories. We compare the limits from dIrr galaxies to those from ultrafaint and classical dSph galaxies previously observed with HAWC. We find that the contraints are comparable to the limits from classical dSph galaxies and 2\thicksim2 orders of magnitude weaker than the ultrafaint dSph limits.Comment: 22 pages, 11 figures, 3 table

    Planck 2013 results. I. Overview of products and scientific results

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