Stochastic simulation and prediction of turbidity dynamics in karst systems. Case study: Mokra karst spring (SE Serbia)

Characterization of a karst system includes the analysis of two components – quantitative and qualitative one. Forecasting of future values of groundwater parameters can be very useful in defining the amounts of water needed for a reliable water supply. Stochastic simulation and forecasting were carried out for time series of precipitation and Mokra karst spring turbidity recorded in 2015. Simulation models within groundwater management would have a function in the early warning system which will enable timely response of groundwater source management.

A Comparative Analysis of Determinants of Household Knowledge of Split and Grouped Mosquito Larval Source Management for Malaria Prevention and Control in Rural Malawi

BackgroundLimited studies have compared determinants of household knowledge of split and grouped mosquito larval source management (LSM) methods. Thus, we compared determinants of household knowledge of split and grouped mosquito LSM methods for malaria control in Malawi. MethodsA cross-sectional study was conducted among 479 households in Nthache, Mwanza district, Malawi. Household knowledge of mosquito LSM methods; draining stagnant water, larviciding, clean environment and clearing grass/bushes were assessed by using a validated structured household questionnaire administered to an adult household member. Chi-square test was used to compare the distribution of household knowledge of each of the split and grouped mosquito LSM methods. Multivariable logistic regression was used to examine factors associated with household knowledge of each of the split and grouped mosquito LSM methods. ResultsHousehold knowledge of draining stagnant water was lower than high-level knowledge of grouped mosquito LSM methods (32.9% versus 83.5%, p=0.000). Household knowledge of clearing grass/bushes was lower than high-level knowledge of grouped mosquito LSM methods (8.2% versus 77.7%, p=0.000). Household knowledge of clean environment was lower than high-level knowledge of grouped mosquito LSM methods (21.8% versus 63.8%, p=0.000). No significant differences were observed between knowledge of larviciding and high-level knowledge of grouped mosquito LSM methods (4.1% versus 5.8%, p=0.421). Respondents without education had 57% less the odds of having knowledge of draining stagnant water than those with primary education (AOR=0.43, 95% CI 0.26-0.69). Those from iron-roofed households and the widowed had three and more than four times the odds of having knowledge of larviciding than those from grass-thatched households and the married (AOR=3.03, 95% CI 1.26-7.29 and AOR=4.73, 95% CI 1.34-16.73), respectively. ConclusionsExcept for larviciding, household knowledge of grouped mosquito LSM methods was significantly higher than split methods. Policy for integrated vector management should address determinants of split mosquito LSM methods to improve household knowledge.

Evaluation of Water Circulation by Modeling: An Example of Nonpoint Source Management in the Yeongsan River Watershed

Owing to urbanization, impervious areas within watersheds have continuously increased, distorting healthy water circulation systems by reducing soil infiltration and base flow; moreover, increases in surface runoff deteriorate water quality by increasing the inflow of nonpoint sources. In this study, we constructed a Hydrological Simulation Program—Fortran (HSPF) watershed model that applies the impervious area and can set medium- and long-term water circulation management goals for watershed sub-areas. The model was tested using a case study from the Yeongsan River watershed, Korea. The results show that impervious land-cover accounts for 18.47% of the upstream reach in which Gwangju City is located; approximately twice the average for the whole watershed. Depending on the impervious area reduction scenario, direct runoff and nonpoint source load could be reduced by up to 56% and 35%, respectively; the water circulation rate could be improved by up to 16%. Selecting management goals requires the consideration of both policy objectives and budget. For urban areas with large impervious cover, the designation of nonpoint source management areas is required. For new cities, it is necessary to introduce water circulation systems (e.g., low impact development techniques) to improve rainwater penetration and recharge and activate preemptive water circulation.

Are Dawn Collections of Anopheles stephensi a Better Method To Estimate the Resting Vector Density? A Study from Chennai, India

The study was an attempt to capture Anopheles stephensi from cattle sheds during dawn to understand the realistic density of the resting mosquitoes. A 2-year longitudinal study was carried out in cattle sheds in close proximity to the human dwellings to collect the resting vector mosquitoes. The man-hour density of A. stephensi ranged from 24.7 to 206.5. The vector incrimination results indicated 0.15% of A. stephensi infected with Pv210 in 2015 and 0.09% in 2016. The current study has revealed that cattle sheds are the preferred resting place of A. stephensi and that dawn is the perfect time to collect and estimate its densities. Hence, adult vector control may also be given due importance in addition to the routine larval source management measures to curb malaria transmission in an urban setting.

Cost of community-led larval source management and house improvement for malaria control: a cost analysis within a cluster-randomized trial in a rural district in Malawi

Background House improvement (HI) to prevent mosquito house entry, and larval source management (LSM) targeting aquatic mosquito stages to prevent development into adult forms, are promising complementary interventions to current malaria vector control strategies. Lack of evidence on costs and cost-effectiveness of community-led implementation of HI and LSM has hindered wide-scale adoption. This study presents an incremental cost analysis of community-led implementation of HI and LSM, in a cluster-randomized, factorial design trial, in addition to standard national malaria control interventions in a rural area (25,000 people), in southern Malawi. Methods In the trial, LSM comprised draining, filling, and Bacillus thuringiensis israelensis-based larviciding, while house improvement (henceforth HI) involved closing of eaves and gaps on walls, screening windows/ventilation spaces with wire mesh, and doorway modifications. Communities implemented all interventions. Costs were estimated retrospectively using the ‘ingredients approach’, combining ‘bottom-up’ and ‘top-down approaches’, from the societal perspective. To estimate the cost of independently implementing each intervention arm, resources shared between trial arms (e.g. overheads) were allocated to each consuming arm using proxies developed based on share of resource input quantities consumed. Incremental implementation costs (in 2017 US$) are presented for HI-only, LSM-only and HI + LSM arms. In sensitivity analyses, the effect of varying costs of important inputs on estimated costs was explored. Results The total economic programme costs of community-led HI and LSM implementation was $626,152. Incremental economic implementation costs of HI, LSM and HI + LSM were estimated as $27.04, $25.06 and $33.44, per person per year, respectively. Project staff, transport and labour costs, but not larvicide or screening material, were the major cost drivers across all interventions. Costs were sensitive to changes in staff costs and population covered. Conclusions In the trial, the incremental economic costs of community-led HI and LSM implementation were high compared to previous house improvement and LSM studies. Several factors, including intervention design, year-round LSM implementation and low human population density could explain the high costs. The factorial trial design necessitated use of proxies to allocate costs shared between trial arms, which limits generalizability where different designs are used. Nevertheless, costs may inform planners of similar intervention packages where cost-effectiveness is known. Trial registration Not applicable. The original trial was registered with The Pan African Clinical Trials Registry on 3 March 2016, trial number PACTR201604001501493

FUZZY RELATIONAL DATABASE MODEL AND MANAGEMANT SYSTEM FOR IMPRECISE INFORMATION

This paper introduces a fuzzy relational database model (FRDB) and the management system for it. FRDB is built by extending the classical relational database model with the fuzzy membership degree of tuples in relations. The management system for FRDB with the querying language like SQL is built by using a classical open-source management system.