Urban Water Pricing: The Metro Manila and Metro Cebu Cases

Water is a critical commodity for human survival and a scarce resource that must be appropriately priced to ensure that it is not wastefully and unsuitably consumed. This Notes offers an optimal pricing scheme, together with suggestions on the improvement of the overall water resource management that could provide the proper environment by which such pricing scheme can succeed.urban management, water sector, water demand

Combining remote sensing-simulation modeling and genetic algorithm optimization to explore water management options in irrigated agriculture

We present an innovative approach to explore water management options in irrigated agriculture considering the constraints of water availability and the heterogeneity of irrigation system properties. The method is two-folds: (i) system characterization using a stochastic data assimilation procedure where the irrigation system properties and operational management practices are estimated using remote sensing (RS) data; and (ii) water management optimization where we explored water management options under various levels of water availability. We set up a soil–water–atmosphere–plant model (SWAP) in a deterministic–stochastic mode for regional modeling. The distributed data, e.g. sowing dates, irrigation practices, soil properties, depth to groundwater and water quality, required as inputs for the regional modeling were estimated by minimizing the residuals between the distributions of field-scale evapotranspiration (ET) simulated by the regional application of SWAP, and by surface energy balance algorithm for land (SEBAL) using two Landsat7 ETM+ images. The derived distributed data were used as inputs in exploring water management options. Genetic algorithm was used in data assimilation and water management optimizations. The case study was conducted in Bata minor (lateral canal), Kaithal, Haryana, India during 2000–2001 rabi (dry) season. Our results showed that under limited water condition, regional wheat yield could improve further if water and crop management practices are considered simultaneously and not independently. Adjusting sowing dates and their distribution in the irrigated area could improve the regional yield, which also complements the practice of deficit irrigation when water availability is largely a constraint. This result was also found in agreement with the scenario that water is non-limited with the exception that the farmers have more degrees of freedom in their agricultural activities. An improvement of the regional yield to 8.5% is expected under the current scenario

Metro Manila and Metro Cebu Groundwater Assessment

This paper describes the methodologies adopted and the results obtained in assessing the groundwater resources of Metro Manila and Metro Cebu. Also some early and recent studies on the aquifer systems in the two metropolis are presented to draw some comparisons on the assessment and data acquisition methods and identify some gaps involved and the improvements needed. Some of the indicators used in assessing groundwater potential and associated problems include storage coefficient, transmissivity, safe yield, and salt water intrusion. The complex and expensive nature of actual field monitoring and analysis has encouraged the use of mathematical models in this study. Specifically, models adopted by NHRC and JICA were used and their respective capabilities, data requirements and modeling results for water balance are described. Although the two models have specific inputs unique to each model and the NHRC model used secondary 9 year data (i.e. 1982-1990) while JICA used one-year actual data (1990), the models gave similar results as far as recharge to groundwater and piezometric heads are concerned. It was found that Metro Manila gets an annual recharge of 206 MCM which is basically due to the high rainfall events during the wet season. Inflows from Laguna lake and leakage from MWSS distribution systems have been also identified as contributors to the recharge. It was also found that due to the over pumping of wells in some coastal areas in Metro Manila, sea water intrusion of aquifers is now becoming a serious problem. The same holds true in Metro Cebu where water for all types of uses comes from groundwater. That is why the annual recharge from rainfall to the aquifer of the Maghaway valley in Cebu amounting to be 1.4 MCM plus an additional inflow of 1.1 MCM coming from riverbeds, are believed to be insufficient to cover the increasing demand for water from all sectors of the society. It is envisioned that a regional scale groundwater and environmental planning scheme for the two metropolis needs to be developed by linking the models with GIS so groundwater data base maps can be overlaid with land use, management practices, recharge distribution and mass loadings of chemicals. A follow-up study which will incorporate this methodology will provide a useful management tool for developing water resources on a regional scale

Groundwater Supply in Metro Manila: Distribution, Environmental and Economic Assessment

Early studies on the groundwater supply of Metro Manila have indicated inefficient resource use that could lead to the eventual decline in the groundwater level, salt water intrusion, and other similar negative externalities. Based on the preceding premise, the paper intends to present a review and assessment of how groundwater resources are developed and utilized in Metro Manila. The study has evaluated technical reports and published literature. It has also adopted water balance models as well as Long-Run Marginal Cost methodologies in calculating the groundwater potential and cost of groundwater pumping. Through these methodologies, the study requires the incorporation of environmental externalities in valuing the unit cost of groundwater extraction. Specific suggestions concerning monitoring systems, aquifer characterization, Geographic Information System application, environmental costs of groundwater pumping, and policy enforcement have been raised. The paper identifies the need to refine the methodology and data set for instituting both supply and demand relationships and projections

Estudio epidemiológico y genotipificación de virus BK en receptores de trasplante renal

El virus BK pertenece a la familia poliomaviridae. Fue clasificado inicialmente en Subtipos I a IV, de acuerdo a su reactividad antigénica. Posteriormente, al estudiar el genoma viral, sustituciones nucleotídicas en el gen VP1, fueron identificadas como responsables de esa diversidad inmunoserológica, dando lugar a la clasificación molecular en Subtipos I a IV y a la visualización, mediante análisis filogenético , de Subgrupos dentro del Subtipo I, los cuales presentan una estrecha relación con poblaciones humanas de etnias determinadas. No se cuenta en Argentina con estudios de prevalencia de los subgrupos mencionados, a excepción de los previos presentados por nuestro Programa en receptores de trasplante renal, en quienes la nefropatía producida por el virus puede llevar a la pérdida del injerto.Facultad de Ciencias Médica

Genetic tool development in marine protists: emerging model organisms for experimental cell biology

Diverse microbial ecosystems underpin life in the sea. Among these microbes are many unicellular eukaryotes that span the diversity of the eukaryotic tree of life. However, genetic tractability has been limited to a few species, which do not represent eukaryotic diversity or environmentally relevant taxa. Here, we report on the development of genetic tools in a range of protists primarily from marine environments. We present evidence for foreign DNA delivery and expression in 13 species never before transformed and for advancement of tools for eight other species, as well as potential reasons for why transformation of yet another 17 species tested was not achieved. Our resource in genetic manipulation will provide insights into the ancestral eukaryotic lifeforms, general eukaryote cell biology, protein diversification and the evolution of cellular pathways. This article has 113 total authors; only 32 are listed here

Feasibility of a walking virtual reality system for rehabilitation: objective and subjective parameters

[EN] Background: Even though virtual reality (VR) is increasingly used in rehabilitation, the implementation of walking navigation in VR still poses a technological challenge for current motion tracking systems. Different metaphors simulate locomotion without involving real gait kinematics, which can affect presence, orientation, spatial memory and cognition, and even performance. All these factors can dissuade their use in rehabilitation. We hypothesize that a marker-based head tracking solution would allow walking in VR with high sense of presence and without causing sickness. The objectives of this study were to determine the accuracy, the jitter, and the lag of the tracking system and its elicited sickness and presence in comparison of a CAVE system. Methods: The accuracy and the jitter around the working area at three different heights and the lag of the head tracking system were analyzed. In addition, 47 healthy subjects completed a search task that involved navigation in the walking VR system and in the CAVE system. Navigation was enabled by natural locomotion in the walking VR system and through a specific device in the CAVE system. An HMD was used as display in the walking VR system. After interacting with each system, subjects rated their sickness in a seven-point scale and their presence in the Slater-Usoh-Steed Questionnaire and a modified version of the Presence Questionnaire. Results: Better performance was registered at higher heights, where accuracy was less than 0.6 cm and the jitter was about 6 mm. The lag of the system was 120 ms. Participants reported that both systems caused similar low levels of sickness (about 2.4 over 7). However, ratings showed that the walking VR system elicited higher sense of presence than the CAVE system in both the Slater-Usoh-Steed Questionnaire (17.6 +/- 0.3 vs 14.6 +/- 0.6 over 21, respectively) and the modified Presence Questionnaire (107.4 +/- 2.0 vs 93.5 +/- 3.2 over 147, respectively). Conclusions: The marker-based solution provided accurate, robust, and fast head tracking to allow navigation in the VR system by walking without causing relevant sickness and promoting higher sense of presence than CAVE systems, thus enabling natural walking in full-scale environments, which can enhance the ecological validity of VR-based rehabilitation applications.The authors wish to thank the staff of LabHuman for their support in this project, especially José Miguel Martínez and José Roda for their assistance. 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