A short review of fecal indicator bacteria in tropical aquatic ecosystems : knowledge gaps and future directions

Given the high numbers of deaths and the debilitating nature of diseases caused by the use of unclean water it is imperative that we have an understanding of the factors that control the dispersion of water borne pathogens and their respective indicators. This is all the more important in developing countries where significant proportions of the population often have little or no access to clean drinking water supplies. Moreover, and notwithstanding the importance of these bacteria in terms of public health, at present little work exists on the persistence, transfer and proliferation of these pathogens and their respective indicator organisms, e.g., fecal indicator bacteria (FIB) such as Escherichia coli and fecal coliforms in humid tropical systems, such as are found in South East Asia or in the tropical regions of Africa. Both FIB and the waterborne pathogens they are supposed to indicate are particularly susceptible to shifts in water flow and quality and the predicted increases in rainfall and floods due to climate change will only exacerbate the problems of contamination. This will be furthermore compounded by the increasing urbanization and agricultural intensification that developing regions are experiencing. Therefore, recognizing and understanding the link between human activities, natural process and microbial functioning and their ultimate impacts on human health are prerequisites for reducing the risks to the exposed populations. Most of the existing work in tropical systems has been based on the application of temperate indicator organisms, models and mechanisms regardless of their applicability or appropriateness for tropical environments. Here, we present a short review on the factors that control FIB dynamics in temperate systems and discuss their applicability to tropical environments. We then highlight some of the knowledge gaps in order to stimulate future research in this field in the tropics

Backward waters, modern waters: Perception-Based Regional Mapping territory uses and water-related sanitary stakes in Luang Phabang area (Lao PDR)

International audienceThis paper examines the suitability of the PBRM, a mapping tool based on the perceptions of local stakeholders, for assessing the connection between land uses and health issues. The area, rural Laos around Luang Phabang city, between the Mekong River valley and mountains, seems to have overcome the formal territorial organization based on exposure risks towards an organization based on access to health and medical facilities. In addition, differential access to safe drinking water has been quite solved by the implementation of private can distribution networks. However, these rapid changes accentuate the social gap between well-connected lowlands and valleys on one hand, and mountain areas on the other hand, increasingly sidelined from this transition. Methodologically, PBRM method explores broader issues at a broader scale but does not give an easy access to non-spatial criteria. Plus, the limits of the SHUs (Spatial Homogeneous Unit) the PBRM establishes are geographically precise regarding topology but not spatiality. These results are action-oriented towards local and development-oriented issues

История формирования календарной лексики в персидском языке

Основная цель данной работы заключается в выявлении корней современной персидской календарной лексики, для чего следует проследить историю календарных систем Ирана, выявить их характерные черты с точки зрения лексики и определить современное состояние календарного пласта в персидском языке

Hydrological consequences of armed conflicts and massive migrations in the Lower Mekong Basin over the second half of the 20th Century. [Abstract only].

Paper presented at the Hydrology Conference 2010, San Diego, California, USA, 11-13 October 2010We investigated whether the Vietnam War bombing and conflict-induced exodus could have altered the hydrological behaviour of the Mekong Basin. The rainfall-runoff relationship was analysed in 2 catchments over period 1960-2004 (figure 1). In each catchment, rainfall and runoff time series together with potential evapotranspiration were used as input to run GR2M monthly water balance model whose robustness is adapted to data-scarce conditions. The space-time distribution of densities of bombs dropped during the war was derived from UXO-NRA database which records the amount and type of ordnances and the aircraft types and numbers per US Air Force sorties from 1965 to 1973. Bomb-induce damages inflicted on vegetation was estimated using the Bomb Damage Assessment Report. We found that the delivery of about 1.5 million tons of high-explosive ordnances likely caused profound damage to one third of the southern catchment whose runoff increased by >365 mm/year during at least 4 years after bombing climaxed in 1972. The magnitude of this increase was found to be consistent with usual tropical forest transpiration rates over the bomb-cleared surface area. No hydrological change was observed during this period in the 30-fold-less bombed catchment located in the North. From 1995 onward, southern and northern catchments' runoff productions are significantly higher and lower than in pre-war conditions, respectively. These hydrological shifts are most likely attributed to permanent changes in the vegetation cover, either denser in the northern sub-catchment (in response to the extensive abandonment of cultivated lands) or sparser in the southern catchment (as a result of bomb-degraded soil conditions). These results illustrate the high responsiveness of flow regime to forest cover changes in tropical areas where deforestation is expected to perpetuate at a high rate over the coming decades

Economic contribution and the potential use of wood charcoal for soil restoration: a case study of village-based charcoal production in Central Laos

Wood charcoal production provides affordable energy in many developing countries and has substantially contributed to the economy through the provision of rural incomes. In several countries, charcoal production leads to overexploitation of forests due to inefficiencies in processing. This study was undertaken in central Laos to (1) examine and document traditional charcoal production systems; (2) investigate the production capacity, recovery efficiencies and economic gains of existing traditional charcoal production methods; (3) characterize the chemical properties of wood charcoal and investigate the potential for soil restoration and (4) investigate local charcoal producers' perception on forest degradation and their species preferences. Through a socio-economic survey, a cost-based method for economic valuation was undertaken on a range of charcoal production methods currently being used. Laboratory chemical analyses were performed on wood charcoal samples. Results indicated that the traditional mud charcoal mound was used by the majority (82%) of charcoal producers. Total charcoal production per production cycle varied between 400 (produced from 2.7 m3 of wood) and 1600 kg (produced from 18 m3 of wood), with a mean of 938 kg (�120) for traditional mud charcoal mounds. The volume of the traditional mud charcoal mounds correlated positively and significantly with total charcoal production (R 2 = 0.45, p?=?0.03), whereas correlated negatively and significantly with the recovery efficiency (R 2 = 0.58, p?=?0.01). On average, the local producers receive a total net benefit of 457,272 Lao kip (USD 57.2) in 17 days. We also identified a rice husk mound method of charcoal production, which may not encourage further deforestation while producing rice husk biochar that can be used for soil restoration. Furthermore, we found that there are significant differences (p < 0.05) between the sampled wood charcoals in chemical properties, indicating that the potential of using wood charcoal for the restoration of degraded soils varies from charcoal to charcoal

Trapping Effi ciencies of Cultivated and Natural Riparian Vegetation of Northern Laos

International audienceIn northern Laos, intensification of cultivation on sloping land leads to accelerated erosion processes. Management of riparian land may counteract the negative impacts of higher sediment delivery rates on water quality. This study assessed water and sediment concentration trapping efficiencies of riparian vegetation in northern Laos and the effect of cultivation of riparian land on water quality. Runoff flowing in and out of selected riparian sites was monitored by means of open troughs. In 2005, two native grass, two bamboo, and two banana sites were monitored. In 2006, adjacent to steep banana, bamboo, and native grass sites, three upland rice sites were established and monitored. Water trapping effi ciency (WTE) and sediment concentration trapping efficiency (SCTE) were calculated on an event basis; means and 95% confi dence intervals (CIs) were estimated with a bootstrapping approach. Confidence intervals were large and overlapping among sites. Seepage conditions severely limited trapping efficiency. Native grass resulted in the highest WTE (95% CI, −0.10 to 0.23), which was not significantly different from zero. Banana resulted in the highest SCTE (95% CI, 0.06–0.40). Bamboo had negative WTE and SCTE. Median outflow runoff from rice sites was nine times the inflow. Median outflow sediment concentration from rice sites was two to five times that of their adjacent sites and two to five times the inflow sediment concentration. Although low tillage banana plantation may reduce sediment concentration of runoff , cultivation of annual crops in riparian land leads to delivery of turbid runoff into the stream, thus severely affecting stream water qualit

Estimation of runoff curve number (CN) of some Laotian land use types

La globalización financiera leída, como un proceso donde los corporativos están afincados en países centrales, que poseen un mayor grado de industrialización, marcan las reglas del juego económico hacia las economías de países periféricos, llamados también emergentes o en vías de industrialización. Las cadenas productivas diferenciadas son una de las consecuencias de este modelo, ya que se focaliza en regiones en donde lideran aquellos procesos estratégicos. Este fenómeno en América Latina, se traduce en la desigualdad en los sistemas económicos de quienes participan en decisiones estratégicas por la influencia de las políticas públicas que se diseñan en beneficio de corporativos transnacionales con mayor poderío. Esto se debe, en gran medida, por influencia de los movimientos de flujos internacionales de capital, los cuales son controlados por inversionistas ubicados en un reducido grupo de países centrales; quienes ven beneficiado su desarrollo económico a costa de distintos recursos que proveen los países periféricos. Las políticas educativas de los países de América Latina deberían acentuar en el modelo capitalista neoliberal, un objetivo de educación financiera, en la búsqueda de un mejor bienestar en la calidad de vida de la población económicamente activa. El presente artículo pretende responder al interrogante del impacto que tiene el modelo neoliberal en el bienestar financiero en una comunidad, el cual, desde el argumento teórico, se diseña para implementar políticas públicas en beneficio del bienestar social