Are Rapid Population Estimates Accurate? A Field Trial of Two Different Assessment Methods.

Emergencies resulting in large-scale displacement often lead to populations resettling in areas where basic health services and sanitation are unavailable. To plan relief-related activities quickly, rapid population size estimates are needed. The currently recommended Quadrat method estimates total population by extrapolating the average population size living in square blocks of known area to the total site surface. An alternative approach, the T-Square, provides a population estimate based on analysis of the spatial distribution of housing units taken throughout a site. We field tested both methods and validated the results against a census in Esturro Bairro, Beira, Mozambique. Compared to the census (population: 9,479), the T-Square yielded a better population estimate (9,523) than the Quadrat method (7,681; 95% confidence interval: 6,160-9,201), but was more difficult for field survey teams to implement. Although applicable only to similar sites, several general conclusions can be drawn for emergency planning

Preoperative left ventricular ejection fraction and left atrium reverse remodeling after mitral regurgitation surgery

Background: Left atrium enlargement has been associated with cardiac events in patients with mitral regurgitation (MR). Left atrium reverse remodeling (LARR) occur after surgical correction of MR, but the preoperative predictors of this phenomenon are not well known. It is therefore important to identify preoperative predictors for postoperative LARR.Methods: We enrolled 62 patients with chronic severe MR (prolapse or flail leaflet) who underwent successful mitral valve surgery (repair or replacement); all with pre-and postoperative echocardiography. LARR was defined as a reduction in left atrium volume index (LAVI) of >= 25%. Stepwise multiple regression analysis was used to identify independent predictors of LARR.Results: LARR occurred in 46 patients (74.2%), with the mean LAVI decreasing from 85.5 mL/m(2) to 49.7 mL/m(2) (p = 25% with a sensitivity of 71.7% and a specificity of 56.3%.Conclusions: LARR occurs frequently after mitral valve surgery and is associated with preoperative LVEF higher than 63.5%.Inst Dante Pazzanese Cardiol, São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, São Paulo, BrazilDisciplina Cardiol, BR-04024002 São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, São Paulo, BrazilWeb of Scienc

The Cs-137 radiological accident in Goiânia, Brazil: Conditions and results of the airborne radiometric survey

This paper describes the details of the aeroradiometric operations, the radiation detection system used and discusses the results. The low-altitude survey was carried out over Goiânia a few days after information of the accident was received by the national competent authority, the Brazilian Nuclear Energy Commission (CNEN). Given the little information at the time of the accident and the urgency to respond to the local and federal authorities, an aerial radiometric survey was proposed to evaluate the extent of the contamination and dispersion of the radioactive powder. The city's entire urban area and nearby dwellings centers, plus the two creeks crossing the city were surveyed in two days. The survey found only one additional contamination point 2.8 x 10-4 C/kg/h (1.1 R/h) that had not yet been identified by ground survey crews. Furthermore, no contamination was found along the margins of the Capim Puba Creek and Meia Ponte rivers which could be contaminated due to rainwater common at that time of the year. Detection tests conducted at different altitudes over the main contamination area showed that the Cs-137 gamma radiation could be detected even at altitudes of 350m above the ground. This was much higher than the 40 m - 70 m decided for the overflights. The survey demonstrated that the contamination was restricted to a few locations in the neighborhood of the metal scrap place where the source shield was broken. These locations were under the control of CNEN radiological emergency response personnel. Such a finding was an important indicator to calm down the population and the government authorities. This allowed concentrating attention on the remediation of the known points of high gamma activity