474 research outputs found
Paving the Way for Development: The Impact of Road Infrastructure on Agricultural Production and Household Wealth in the Democratic Republic of Congo
Given its vast land resources and favorable water supply, the Democratic Republic of Congo's (DRC) natural agricultural potential is immense. However, the economic potential of the sector is handicapped by one of the most dilapidated transport systems in the developing world (World Bank, 2006). Road investments are therefore a high priority in the government's investment plans, and those of its major donors. Whilst these are encouraging signs, very little is known about how the existing road network constrains agricultural and rural development, and how these new road investments would address these constraints. To inform this issue the present paper primarily employs GIS-based data to assess the impact of market access on agricultural and rural development (ARD). Compared to existing work, however, the paper makes a number of innovations to improve and extend the generic techniques used to estimate the importance of market access for ARD. First, the DRC road network data is augmented with survey-based data from Minten and Kyle (1999) on agricultural transport times to calculate improved “market access” measures for the DRC. Second, we follow Dorosh et al (2009) in estimating the long run relationship between market access and agricultural production, although we also investigate the relationship with household wealth. Finally, we run simulations of how proposed infrastructure investments would affect market access, and how market access would in turn affect agricultural production and household wealth.Infrastructure, market access, road and river transport, agricultural production, poverty., Agricultural and Food Policy, Crop Production/Industries, Food Security and Poverty, Production Economics,
Economic Methodology for Pasture Grass and Legume Seed Production
The importance and complexity of the industrial process of seed production is known. Thus, conditions should be established for achieving and efficiently controlling the activity in order to know production costs, selling prices and to guarantee economic efficiency. The objective of this paper was to evaluate from an economic point of view, seed production of species of tropical grasses and legumes based on a preliminary methodology facilitating the control of the whole activity
Identification of optimal investments
Biofortification is regarded as a complement to supplementation, industrial fortification and dietary diversification in the fight against micronutrient deficiencies. It is important therefore to first identify areas where biofortification may have high impact and prioritize these areas for more in-depth analysis. HarvestPlus has developed the Biofortification Prioritization Index (BPI), which ranks countries globally according to their suitability for investment in biofortification interventions. HarvestPlus is also conducting ex ante micronutrient intervention portfolio analyses, designed to simulate the implementation and impact of a biofortification program in countries which have been identified as suitable candidates for investment. Micronutrient intervention portfolio studies offer the ability to distinguish production, consumption and inadequate micronutrient intake at a more disaggregated level and offer a complementary design and planning tool to simulate the implementation of biofortification and examine its potential impact and cost-effectiveness among different approaches. In addition, these studies are designed to examine multiple interventions within a country, to better understand biofortification’s role in reducing micronutrient deficiency when considered among a suite of interventions. This case study of Zambia demonstrates how these tools can be used to assess the potential impact of biofortification, quantify its cost-effectiveness and examine how it interacts with and complements other interventions. Given the long-term nature of biofortification as an intervention investment, future analyses should continue to incorporate various scenarios including continued investment in sustainable development and the effects of climate change which are likely to condition the impact of biofortification and other interventions.Keywords: Biofortification, Biofortification Priority Index (BPI), Cost-effectiveness, Household Consumption and Expenditure Surveys (HCES
The Bulge-Disk Orthogonal Decoupling in Galaxies: NGC 4698
The R-band isophotal map of the Sa galaxy NGC 4698 shows that the inner
region of the bulge structure is elongated perpendicularly to the major axis of
the disk, this is also true for the outer parts of the bulge if a parametric
photometric decomposition is adopted. At the same time the stellar component is
characterized by an inner velocity gradient and a central zero-velocity plateau
along the minor and major axis of the disk respectively. This remarkable
geometric and kinematic decoupling suggests that a second event occurred in the
formation history of this galaxy.Comment: 12 pages, LaTex, with 4 PostScript figures. Accepted for publication
in The Astrophysical Journal Letter
Star Formation in Satellite Galaxies
We present narrow-band observations of the H emission in a sample of
31 satellite orbiting isolated giant spiral galaxies. The sample studied spans
the range mag. The H emission was detected in all the
spiral and irregular objects with fluxes in the range erg cm s. The average and maximum values for the
current star formation rates are 0.68 and 3.66 M_\sun yr respectively.
Maps of the spatial distribution of ionized gas are presented. The star-forming
regions show a rich structure in which frequently discrete complexes are
imposed over more diffuse structures. In general, the current star formation
rates are smaller that the mean values in the past obtained from the current
stellar content; this probably indicates a declining rhythm with time in the
generation of new stars. However, the reserve of gas is enough to continue
fueling the current levels of star formation activity for at least another
Hubble time. Four of the objects (NGC 2718b, NGC 4541e, NGC 5965a and NGC
5965a) with higher current star formation rates show clear signs of
interaction with close companions of comparable brightness at projected
distances of 25, 20 and 2 kpc respectively. The only two galaxies in our sample
that do not show star formation activity are members of these interacting
systems, and it is unclear if this is a consequence of intrinsic properties
(both are Hubble early types) or if it is related with possible disruption of
the external parts due to the interaction. In the case of the pair NGC 2718a-b
there are indications of gas transport between both galaxies.Comment: 25 pages, 11 figures. Accepted for publication in A
Evidences of volcanic unrest on high-temperature fumaroles by satellite thermal monitoring: The case of Santa Ana volcano, El Salvador
International audienceOn October 1st, 2005, Santa Ana volcano (El Salvador) underwent a VEI 3 phreatomagmatic eruption after approximately one century of rest. Casualties and damages to some of the local infrastructures and surrounding plantations were followed by the evacuation of the nearby communities. The analysis of MODIS (Moderate Resolution Imaging Spectroradiometer) infrared data reveals that the main explosion was preceded by a one-year-long thermal unrest, associated to the development of a fumaroles field, located at the western rim of the summit crater lake. By combining space-based thermal flux and ground-based measurements (seismicity, sulfur emissions and lake temperatures), we suggest that the activity observed at Santa Ana between 2004 and 2005 was driven by the gradual intrusion of an undegassed magma body at a very shallow depth. Magma injection induced thermal anomalies associated with sustained degassing from the fumaroles field and promoted the interaction between the magmatic-hydrothermal system and the overlying water table. This process culminated into the VEI 3 phreatomagmatic eruption of October 2005 that strongly modified the shallow structure of the crater area. The subsequent three-years-long activity resulted from self-sealing of the fracture system and by the opening of a new fracture network directly connecting the deeper hydrothermal system with the crater lake. Our results show that satellite-based thermal data allow us to detect the expansion of the high-temperature fumarolic field. This may precede an explosive eruption and/or a lava dome extrusion. In particular, we show that thermal records can be analyzed with other geochemical (i.e. SO2 emissions) and geophysical (seismicity) data to track a shallow magmatic intrusion interacting with the surrounding hydrothermal system. This provides a remarkable support for volcano monitoring and eruption forecasting, particularly in remote areas where permanent ground data acquisition is hazardous, expensive and difficult
The Spitzer Local Volume Legacy: Survey Description and Infrared Photometry
The survey description and the near-, mid-, and far-infrared flux properties
are presented for the 258 galaxies in the Local Volume Legacy (LVL). LVL is a
Spitzer Space Telescope legacy program that surveys the local universe out to
11 Mpc, built upon a foundation of ultraviolet, H-alpha, and HST imaging from
11HUGS (11 Mpc H-alpha and Ultraviolet Galaxy Survey) and ANGST (ACS Nearby
Galaxy Survey Treasury). LVL covers an unbiased, representative, and
statistically robust sample of nearby star-forming galaxies, exploiting the
highest extragalactic spatial resolution achievable with Spitzer. As a result
of its approximately volume-limited nature, LVL augments previous Spitzer
observations of present-day galaxies with improved sampling of the
low-luminosity galaxy population. The collection of LVL galaxies shows a large
spread in mid-infrared colors, likely due to the conspicuous deficiency of 8um
PAH emission from low-metallicity, low-luminosity galaxies. Conversely, the
far-infrared emission tightly tracks the total infrared emission, with a
dispersion in their flux ratio of only 0.1 dex. In terms of the relation
between infrared-to-ultraviolet ratio and ultraviolet spectral slope, the LVL
sample shows redder colors and/or lower infrared-to-ultraviolet ratios than
starburst galaxies, suggesting that reprocessing by dust is less important in
the lower mass systems that dominate the LVL sample. Comparisons with
theoretical models suggest that the amplitude of deviations from the relation
found for starburst galaxies correlates with the age of the stellar populations
that dominate the ultraviolet/optical luminosities.Comment: Accepted for publication in ApJ; Figures 1,8,9 provided as jpeg
Determinación de Mercurio, Cadmio, Plomo y Arsénico en ríos de la zona minera de la subcuenca del Río Titihuapa, Cabañas, El Salvador, C.A.
The sub-basin of the Titihuapa River in the department of Cabañas houses part of the Tertiary volcanism of El Salvador in that region, and therefore has an abundance of minerals. The mining activity that developed since the end of the 19th century, made this area appear as one of the most favorable for the exploitation of gold and silver in El Salvador. However, this mining prosperity could have led to the metallic contamination of a good part of the Titihuapa river basin. The methodology used included taking sediment samples at sites located at the confluence points of the tributary rivers to the Titihuapa sub-basin, which were protected and transported to the laboratory for their respective analysis using atomic absorption techniques, graphite furnace method. and flame generator method. The Slight Effects Level (NEL) of the Guide for the Evaluation of Sediments, of the Department of Environmental Protection of New Jersey, 1998 was used as a parameter. The concentrations of Hg, Cd and Pb are below the values of the NEL. As concentrations, most of them exceed the NEL which is 6.0 µg / g.La subcuenca del río Titihuapa en el departamento de Cabañas alberga parte del vulcanismo Terciario de El Salvador en esa región, y por ende posee una abundancia de minerales. La actividad minera que se desarrolló desde finales del siglo XIX, hizo figurar a esta zona como una de las más propicias para la explotación de oro y plata en El Salvador. Sin embargo, esta prosperidad minera, pudo haber propiciado la contaminación metálica de buena parte de la cuenca del río Titihuapa. La metodología empleada incluyó la toma de muestras de sedimentos en sitios ubicados en los puntos de confluencia de los ríos tributarios a la subcuenca Titihuapa, las cuales fueron resguardadas y transportadas al laboratorio para su respectivo análisis mediante técnicas de absorción atómica, método de horno de grafito y método de generador de flama. Se usó como parámetro el Nivel de Efectos Leves (NEL) de la Guía Para la Evaluación de Sedimentos, del departamento de Protección Ambiental de New Jersey, 1998. Las concentraciones de Hg, Cd y Pb están por debajo de los valores de la NEL. Las concentraciones de As, la mayoría sobrepasa el NEL que es de 6.0 μg/g
La formación docente en venezuela en el contexto de la consulta nacional por la calidad educativa: apuntes preliminares para el desarrollo de las políticas de formación docente.
Este artículo constituye un acercamiento al contexto educativo en el cual se produce el debate nacional sobre la Consulta Nacional por la Calidad Educativa en su fase culminante, a través de una mirada a la formación inicial de docentes para el subsistema de Educación Básica. Esta convocatoria realizada por el Ejecutivo del país por intermedio del Ministerio del Poder Popular para la Educación (MPPE) ocurre en un complejo clima político y social del país, sometido desde hace más de una década a las presiones políticas y económicas de fuerzas internas apuntaladas por el poder político y económico transnacional que amenazan seriamente la pervivencia del proceso revolucionario Bolivariano, y cuyo único propósito es revertir las conquistas políticas y sociales logradas en este tiempo de cambios en todos los órdenes. De allí que, a los efectos del presente escrito, se hará particular énfasis en el tema de la formación inicial de los docentes, en particular desde la mirada de la evolución de este proceso, reconocido actualmente como uno de los problemas recurrentes que, pese a diferentes iniciativas orientadas hacia el diseño de una política en esta dirección, sigue siendo una de las materias pendientes del actual proceso político venezolano
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