Management of vector population is a commonly used method for mitigating transmission of mosquito-borne infections, but quantitative information on its practical public health impact is scarce. We study the effectiveness of Ultra-Low Volume (ULV) insecticide spraying in public spaces for preventing secondary dengue virus (DENV) cases in Porto Alegre, a non-endemic metropolitan area in Brazil. We developed a stochastic transmission model based on detailed entomological, epidemiological and population data, accounting for the geographical distribution of mosquitoes and humans in the study area and spatial transmission dynamics. The model was calibrated against the distribution of DENV cluster sizes previously estimated from the same geographical setting. We estimated a ULV-induced mortality of 40% for mosquitoes and found that the implemented control protocol avoided about 24% of symptomatic cases occurred in the area throughout the 2015–2016 epidemic season. Increasing the radius of treatment or the mortality of mosquitoes by treating gardens and/or indoor premises would greatly improve the result of control, but trade-offs with respect to increased efforts need to be carefully analyzed. We found a moderate effectiveness for ULV-spraying in public areas, mainly due to the limited ability of this strategy in effectively controlling the vector population. These results can be used to support the design of control strategies in low-incidence, non-endemic settings.
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AbstractThe majority of the petroleum engineers agree that fracture pressure gradient is one of the most important items to be considered when designing or drilling a well.The perception of the importance of the fracture pressure gradient comes from the results of the severe economic losses that the oil industry has faced when dealing with lost circulation related problems. In the worst scenario, these problems can escalate to a blowout due to the reduction of the hydrostatic pressure in the well. In addition, lost circulation problems are likely to occur and become even harder to control if the well is in deepwater.It is well known that a correct prediction of the fracture pressure gradient minimize drilling problems. However, the methods used by oil industry to perform this task are generally based on equations or methodologies that give questionable results and do not match actual field data.Fracture pressure gradient methods are generally based either on equation derived from rock mechanics theories or in simplified methods. Although, the first tries to closely represent the rocks underground behavior, they are too complex and call for a number of data that normally are not available. On the other side, the second carries many simplifications and barely represents subsurface conditions. However, the last is simple to use and consequently more popular among drilling personnel. Regardless of the method, a good calibration, in general hard to be accomplished, is always necessary to provide good estimates.Finally, performing leak off tests (LOT) is usually the procedure carried out by most of the oil companies to establish fracture pressure gradient values for a given area. Once LOT`s are obtained, they are used to calibrate simple equations or will be part of the company database to simply build fracture pressure gradient curves.The objective of this work is to make a critical examination of the current methods used to estimate fracture pressure gradient. The work also presents simple methodologies based on leak of tests data to estimate fracture pressure gradient for a given area. Results based on actual field data to exemplify the use of the presented methodology will be shown, mostly for deepwater oilfield.
Unhealthy diet is an important health problem in the region of the Americas, and Uruguay does not escape this reality. Nutritional problems in Uruguayan school-age children are overweight and obesity. Caloric intake is excessive for 60% of children and 28% of calories come from ultra-processed products (UPP) [CODICEN 2021] [MIDES 2020) (Köncke, Toledo, 2021). In 2018, an evaluation of food intake was conducted in a representative sample of public schools in the city of Montevideo. Food and preparations were categorized according to the NOVA system, later they were analyzed according to the Pan American Health Oganization nutrient profile model (PAHO NPM). Only 0.52% of children consumed exclusively natural foods, unprocessed, minimally processed or culinary ingredients. Twenty-five percent of children consumed ≥ 4 products categorized with excessive content of free sugars, total fat or saturated fat according to the PAHO NPM; in the case of excessive sodium this was 40%. In general, children who included products with excessive free sugars, sodium or saturated fat in their diet exceeded the limits established by PAHO and as a result their diet is of poorer nutritional quality compared to children who did not consume such products.
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