399 research outputs found

    Diagnóstico Territorial Integral del municipio de Ciudad Darío

    Get PDF
    EN ESTE ARTÍCULO SE PRESENTA EL “DIAGNÓSTICO TERRITORIAL INTEGRAL de Ciudad Darío” realizado como trabajo de fin de curso de la Maestría en Desarrollo Rural de la Universidad Centroamericana. Este estudio ha buscado contribuir a la formulación de propuestas de intervención de los actores sociales del municipio de Ciudad Darío sobre los procesos estratégicos de desarrollo del territorio. Se realizó unazonificación integral del municipio, identificándose cuatro zonas: una zona alta, campesina de agricultura de subsistencia; una zona de laderas secas; una planicie seca de latifundio ganadero; y finalmente, una zona de llanos y vegas fértiles de riego semi-intensivo. Posteriormente, se identificaron y clasificaron por capital (ambiental, económico, social-humano y político-institucional) y nivel territorial, los principales procesos de cambio que afectan o podrían afectar al municipio. Su análisis permitió caracterizar las principales oportunidades y amenazas para el desarrollo del territorio y, al relacionarlo con las fortalezas y debilidades identificadas en la zonificación, evidenciar los principales factores que podrían incidir en el municipio y sus principales retos. Para enfrentar estos retos, se identificaron tres ejes estratégicos: la reducción de los niveles de inseguridad alimentaria y vulnerabilidad ambiental del municipio; el fomento integral de las cadenas de producción de hortalizas; y la prevención de riesgos sociales. Para cada uno de estos ejes se ha definido un conjunto de acciones ordenadas por capital y nivel territorial, orientadas a incidir sobre los principales procesos de cambio identificados. Finalmente, se definieron ejes estratégicos transversales enfocados al desarrollo de capacidades de incidir sobre los procesos claves de desarrollo del municipio

    Economic Partnership Agreements: Assessing Potential Implications from Some Alternative Scenarios

    Get PDF
    This paper has evaluated the possible effects of the Economic Partnership Agreement using a global general equilibrium modelling framework, namely the GTAP model. The latest version of the GTAP database (version 6.22) has been employed as a benchmark database. The study has explored the implications of different EPA scenarios (in terms of changes in GDP, exports, and other measures for welfare) for ACP countries (both developing and LDCs), based on the sample of countries in the database

    Economic Partnership Agreements: Assessing Potential Implications from Some Alternative Scenarios

    Get PDF
    This paper has evaluated the possible effects of the Economic Partnership Agreement using a global general equilibrium modelling framework, namely the GTAP model. The latest version of the GTAP database (version 6.22) has been employed as a benchmark database. The study has explored the implications of different EPA scenarios (in terms of changes in GDP, exports, and other measures for welfare) for ACP countries (both developing and LDCs), based on the sample of countries in the database

    First detection of water vapor in a pre-stellar core

    Get PDF
    Water is a crucial molecule in molecular astrophysics as it controls much of the gas/grain chemistry, including the formation and evolution of more complex organic molecules in ices. Pre-stellar cores provide the original reservoir of material from which future planetary systems are built, but few observational constraints exist on the formation of water and its partitioning between gas and ice in the densest cores. Thanks to the high sensitivity of the Herschel Space Observatory, we report on the first detection of water vapor at high spectral resolution toward a dense cloud on the verge of star formation, the pre-stellar core L1544. The line shows an inverse P-Cygni profile, characteristic of gravitational contraction. To reproduce the observations, water vapor has to be present in the cold and dense central few thousand AU of L1544, where species heavier than Helium are expected to freeze-out onto dust grains, and the ortho:para H2 ratio has to be around 1:1 or larger. The observed amount of water vapor within the core (about 1.5x10^{-6} Msun) can be maintained by Far-UV photons locally produced by the impact of galactic cosmic rays with H2 molecules. Such FUV photons irradiate the icy mantles, liberating water wapor in the core center. Our Herschel data, combined with radiative transfer and chemical/dynamical models, shed light on the interplay between gas and solids in dense interstellar clouds and provide the first measurement of the water vapor abundance profile across the parent cloud of a future solar-type star and its potential planetary system.Comment: The Astrophysical Journal Letters, in pres

    Herschel HIFI observations of O2_2 toward Orion: special conditions for shock enhanced emission

    Get PDF
    We report observations of molecular oxygen (O2_2) rotational transitions at 487 GHz, 774 GHz, and 1121 GHz toward Orion Peak A. The O2 lines at 487 GHz and 774 GHz are detected at velocities of 10-12 km/s with line widths 3 km/s; however, the transition at 1121 GHz is not detected. The observed line characteristics, combined with the results of earlier observations, suggest that the region responsible for the O2_2 emission is 9" (6e16 cm) in size, and is located close to the H2 Peak 1position (where vibrationally-excited H2_2 emission peaks), and not at Peak A, 23" away. The peak O2 column density is 1.1e18/cm2. The line velocity is close to that of 621 GHz water maser emission found in this portion of the Orion Molecular Cloud, and having a shock with velocity vector lying nearly in the plane of the sky is consistent with producing maximum maser gain along the line-of-sight. The enhanced O2_2 abundance compared to that generally found in dense interstellar clouds can be explained by passage of a low-velocity C-shock through a clump with preshock density 2e4/cm3, if a reasonable flux of UV radiation is present. The postshock O2_2 can explain the emission from the source if its line of sight dimension is ~10 times larger than its size on the plane of the sky. The special geometry and conditions required may explain why O2_2 emission has not been detected in the cores of other massive star-forming molecular clouds.Comment: 28 pages, 13 figure

    13C—methyl formate : observations of a sample of high mass starforming regions including Orion—KL and spectroscopic characterization

    Get PDF
    We have surveyed a sample of massive star-forming regions located over a range of distances from the Galactic centre for methyl formate, HCOOCH3, and its isotopologues H13COOCH3 and HCOO13CH3. The observations were carried out with the APEX telescope in the frequency range 283.4-287.4 GHz. Based on the APEX observations, we report tentative detections of the 13C-methyl formate isotopologue HCOO13CH3 towards the following four massive star-forming regions: Sgr B2(N-LMH), NGC 6334 IRS 1, W51 e2 and G19.61-0.23. In addition, we have used the 1 mm ALMA science verification observations of Orion-KL and confirm the detection of the 13C-methyl formate species in Orion-KL and image its spatial distribution. Our analysis shows that the 12C/13C isotope ratio in methyl formate toward Orion-KL Compact Ridge and Hot Core-SW components (68.4±10.1 and 71.4±7.8, respectively) are, for both the 13C-methyl formate isotopologues, commensurate with the average 12C/13C ratio of CO derived toward Orion-KL. Likewise, regarding the other sources, our results are consistent with the 12C/13C in CO. We also report the spectroscopic characterization, which includes a complete partition function, of the complex H13COOCH3 and HCOO13CH3 species. New spectroscopic data for both isotopomers H13COOCH3 and HCOO13CH3, presented in this study, has made it possible to measure this fundamentally important isotope ratio in a large organic molecule for the first time.This work was supported by the National Science Foundation under grant 1008800. We are grateful to the Ministerio de Economia y Competitividad of Spain for the financial support through grant No. FIS2011-28738-C02-02 and to the French Government through grant No. ANR-08-BLAN-0054 and the French PCMI (Programme National de Physique Chimie du Milieu Interstellaire). This paper makes use of the following ALMA data: ADS/JAO. ALMA#2011.0.00009.SV.ALMAis a partnership of ESO (representing its member states), NSF (USA), and NINS (Japan), together with NRC (Canada) and NSC and ASIAA (Taiwan), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO, and NAOJ. C.F. thanks Dahbia Talbi, Eric Herbst, and Anthony Remijan for enlightening discussions. Finally, we thank the anonymous referee for helpful comments

    Effects of sodium nitrite reduction, removal or replacement on cured and cooked meat for microbiological growth, food safety, colon ecosystem, and colorectal carcinogenesis in Fischer 344 rats

    Get PDF
    Epidemiological and experimental evidence indicated that processed meat consumption is associated with colorectal cancer risks. Several studies suggest the involvement of nitrite or nitrate additives via N-nitroso-compound formation (NOCs). Compared to the reference level (120 mg/kg of ham), sodium nitrite removal and reduction (90 mg/kg) similarly decreased preneoplastic lesions in F344 rats, but only reduction had an inhibitory effect on Listeria monocytogenes growth comparable to that obtained using the reference nitrite level and an effective lipid peroxidation control. Among the three nitrite salt alternatives tested, none of them led to a significant gain when compared to the reference level: vegetable stock, due to nitrate presence, was very similar to this reference nitrite level, yeast extract induced a strong luminal peroxidation and no decrease in preneoplastic lesions in rats despite the absence of NOCs, and polyphenol rich extract induced the clearest downward trend on preneoplastic lesions in rats but the concomitant presence of nitrosyl iron in feces. Except the vegetable stock, other alternatives were less efficient than sodium nitrite in reducing L. monocytogenes growth

    Acute health risks to community hand-pumped groundwater supplies following cyclone Idai flooding

    Get PDF
    This longitudinal flood-relief study assessed the impact of the March 2019 Cyclone Idai flood event on E. coli contamination of hand-pumped boreholes in Mulanje District, Malawi. It established the microbiological water-quality safety of 279 community supplies over three phases, each comprising water-quality survey, rehabilitation and treatment verification monitoring. Phase 1 contamination three months after Idai was moderate, but likely underestimated. Increased contamination in Phase 2 at 9 months and even greater in Phase 3, a year after Idai was surprising and concerning, with 40% of supplies then registering E. coli contamination and 20% of supplies deemed 'unsafe'. Without donor support for follow-up interventions, this would have been missed by a typical single-phase flood-relief activity. Contamination rebound at boreholes successfully treated months earlier signifies a systemic problem from persistent sources intensified by groundwater levels likely at a decade high. Problem extent in normal, or drier years is unknown due to absence of routine monitoring of water point E. coli in Malawi. Statistical analysis was not conclusive, but was indicative of damaged borehole infrastructure and increased near-borehole pit-latrine numbers being influential. Spatial analysis including groundwater flow-field definition (an overlooked sector opportunity) revealed 'hit-and-miss' contamination of safe and unsafe boreholes in proximity. Hydrogeological control was shown by increased contamination near flood-affected area and in more recent recharge groundwater otherwise of good quality. Pit latrines are presented as credible e-coli sources in a conceptual model accounting for heterogeneous borehole contamination, wet season influence and rebound behavior. Critical to establish are groundwater level - flow direction, hand-pump plume draw, multiple footprint latrine sources - 'skinny' plumes, borehole short-circuiting and fast natural pathway (e.g. fracture flow) and other source influences. Concerted WASH (Water, Sanitation and Hygiene) sector investment in research and policy driving national water point based E. coli monitoring programs are advocated. [Abstract copyright: Copyright © 2021. Published by Elsevier B.V.
    corecore