20 research outputs found

    Beekeeping in Jalisco, México

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    The purpose of this study was to analyze the socioeconomic factors that influence the beekeeping process and describe the current situation in beekeeping technology development in the south and southeast regions of Jalisco. The study was conducted by reviewing secondary sources of documentary information and the primary information was obtained by means of a survey, analyzing demographic, social, technological, and economic variables. From January to April 2011, a stratified sampling was conducted of six strata of beekeepers, with a final sampling of 183 beekeepers. We applied a frequency analysis, ANOVA (Waller-Duncan), and contingency tables (χ2). The average age observed for the beekeepers was 47 years, with fewer women participating in the activity, and an above national average level of education. The majority keep their apiaries in rented premises, a high percentage outside the municipality where they live. The honey obtained is multiflora and the main harvest is in the autumn, with a honey yield per hive below the national average. A number of problems affect the production sector including environmental factors, production costs, and varroa. We observed little diversification; in addition to honey only beeswax is recovered, and only a minority keep a record of production costs. There is wide participation in beekeeping associations and in training provided by different public and private bodies. There is a willingness to adopt new technologies and equipment for honey production with good practice standards

    Emergent global oscillations in heterogeneous excitable media: The example of pancreatic beta cells

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    Using the standard van der Pol-FitzHugh-Nagumo excitable medium model I demonstrate a novel generic mechanism, diversity, that provokes the emergence of global oscillations from individually quiescent elements in heterogeneous excitable media. This mechanism may be operating in the mammalian pancreas, where excitable beta cells, quiescent when isolated, are found to oscillate when coupled despite the absence of a pacemaker region.Comment: See home page http://lec.ugr.es/~julya

    Planck 2013 results. XXII. Constraints on inflation

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    We analyse the implications of the Planck data for cosmic inflation. The Planck nominal mission temperature anisotropy measurements, combined with the WMAP large-angle polarization, constrain the scalar spectral index to be ns = 0:9603 _ 0:0073, ruling out exact scale invariance at over 5_: Planck establishes an upper bound on the tensor-to-scalar ratio of r < 0:11 (95% CL). The Planck data thus shrink the space of allowed standard inflationary models, preferring potentials with V00 < 0. Exponential potential models, the simplest hybrid inflationary models, and monomial potential models of degree n _ 2 do not provide a good fit to the data. Planck does not find statistically significant running of the scalar spectral index, obtaining dns=dln k = 0:0134 _ 0:0090. We verify these conclusions through a numerical analysis, which makes no slowroll approximation, and carry out a Bayesian parameter estimation and model-selection analysis for a number of inflationary models including monomial, natural, and hilltop potentials. For each model, we present the Planck constraints on the parameters of the potential and explore several possibilities for the post-inflationary entropy generation epoch, thus obtaining nontrivial data-driven constraints. We also present a direct reconstruction of the observable range of the inflaton potential. Unless a quartic term is allowed in the potential, we find results consistent with second-order slow-roll predictions. We also investigate whether the primordial power spectrum contains any features. We find that models with a parameterized oscillatory feature improve the fit by __2 e_ _ 10; however, Bayesian evidence does not prefer these models. We constrain several single-field inflation models with generalized Lagrangians by combining power spectrum data with Planck bounds on fNL. Planck constrains with unprecedented accuracy the amplitude and possible correlation (with the adiabatic mode) of non-decaying isocurvature fluctuations. The fractional primordial contributions of cold dark matter (CDM) isocurvature modes of the types expected in the curvaton and axion scenarios have upper bounds of 0.25% and 3.9% (95% CL), respectively. In models with arbitrarily correlated CDM or neutrino isocurvature modes, an anticorrelated isocurvature component can improve the _2 e_ by approximately 4 as a result of slightly lowering the theoretical prediction for the ` <_ 40 multipoles relative to the higher multipoles. Nonetheless, the data are consistent with adiabatic initial conditions

    Planck 2015 results. XX. Constraints on inflation

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    We present the implications for cosmic inflation of the Planck measurements of the cosmic microwave background (CMB) anisotropies in both temperature and polarization based on the full Planck survey. The Planck full mission temperature data and a first release of polarization data on large angular scales measure the spectral index of curvature perturbations to be n s = 0.968 ± 0.006 and tightly constrain its scale dependence to dn s /dlnk = −0.003 ± 0.007 when combined with the Planck lensing likelihood. When the high-ℓ polarization data is included, the results are consistent and uncertainties are reduced. The upper bound on the tensor-to-scalar ratio is r 0.002 <0.11 (95% CL), consistent with the B-mode polarization constraint r<0.12 (95% CL) obtained from a joint BICEP2/Keck Array and Planck analysis. These results imply that V(ϕ)∝ϕ 2 and natural inflation are now disfavoured compared to models predicting a smaller tensor-to-scalar ratio, such as R 2 inflation. Three independent methods reconstructing the primordial power spectrum are investigated. The Planck data are consistent with adiabatic primordial perturbations. We investigate inflationary models producing an anisotropic modulation of the primordial curvature power spectrum as well as generalized models of inflation not governed by a scalar field with a canonical kinetic term. The 2015 results are consistent with the 2013 analysis based on the nominal mission data

    Nivel tecnológico de invernadero y riesgo para la salud de los jornaleros

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    Abstract Introduction: The greenhouses are classified by under high levels or as technologies to be adapted to create optimal conditions of radiation, temperature, humidity and carbon dioxide that improve agricultural production and the development of organisms harmful that fight applying pesticides, exposing laborers to vapors and waste. Method: The cytotoxic damage was determined in samples of oral epithelial cells exfoliation of day laborers through the micronucleus assay, 40 laborers exposed to pesticides, 20 worked in greenhouses low-tech and high-tech 20. Results: The low-tech results showed higher frequency for all nuclear abnormalities compared to the control group, especially of condensed chromatin, picnosis, karyolysis and micronuclei. In calculating the risk, the frequency of micronuclei was measured at odds ratio (OR) for laborers in high-tech greenhouses OR = 17.06 (95 % CI 3.4-83.7) and low-tech OR = 50.66 (% CI 7.5 -341.7). Conclusion: The results indicate that the laborers who work in low-tech greenhouses show a higher frequency of cells with nuclear abnormalities, due to the effect of working conditions and exposure to pesticides.Resumen Introducción: Los invernaderos se clasifican por niveles alto, medio o bajo según las tecnologías que se le adapten, con la que se crean condiciones óptimas de radiación, temperatura, humedad y dióxido de carbono que permiten mejorar la producción agrícola, así como el desarrollo de organismos perjudiciales que se combaten aplicando plaguicidas, exponiendo a los jornaleros a sus vapores y residuos. Método: Se determinó el daño genotóxico en muestras de células epiteliales de exfoliación bucal de los jornaleros a través del ensayo de micronúcleos, de 40 jornaleros expuestos a plaguicidas, 20 laboraron en invernaderos de baja tecnología y 20 en invernaderis de tecnología alta. Resultados: Los de baja tecnología mostraron resultados más altos de frecuencias para todas las anormalidades nucleares comparando con el grupo control, especialmente de cromatina condensada, picnosis, cariolisis y micronúcleos. Al calcular el riesgo, se midió las frecuencias de micronúcleos en razón de probabilidades (OR), para los jornaleros de invernaderos de alta tecnología el OR = 17.06 (95 % IC 3.4-83.7) y de baja tecnología OR = 50.66 (% IC 7.5-341.7). Conclusión: Los resultados indican que los jornaleros que laboran en invernaderos de baja tecnología muestran una mayor frecuencia de células con anormalidades nucleares, debido al efecto de condiciones laborales y exposición a los plaguicidas
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