Regional-scale assessment of soil salinity in the Red River Valley using multi-year MODIS EVI and NDVI.

The ability to inventory and map soil salinity at regional scales remains a significant challenge to scientists concerned with the salinization of agricultural soils throughout the world. Previous attempts to use satellite or aerial imagery to assess soil salinity have found limited success in part because of the inability of methods to isolate the effects of soil salinity on vegetative growth from other factors. This study evaluated the use of Moderate Resolution Imaging Spectroradiometer (MODIS) imagery in conjunction with directed soil sampling to assess and map soil salinity at a regional scale (i.e., 10-10(5) km(2)) in a parsimonious manner. Correlations with three soil salinity ground truth datasets differing in scale were made in Kittson County within the Red River Valley (RRV) of North Dakota and Minnesota, an area where soil salinity assessment is a top priority for the Natural Resource Conservation Service (NRCS). Multi-year MODIS imagery was used to mitigate the influence of temporally dynamic factors such as weather, pests, disease, and management influences. The average of the MODIS enhanced vegetation index (EVI) for a 7-yr period exhibited a strong relationship with soil salinity in all three datasets, and outperformed the normalized difference vegetation index (NDVI). One-third to one-half of the spatial variability in soil salinity could be captured by measuring average MODIS EVI and whether the land qualified for the Conservation Reserve Program (a USDA program that sets aside marginally productive land based on conservation principles). The approach has the practical simplicity to allow broad application in areas where limited resources are available for salinity assessment.

Obstrução estrangulada de jejuno como complicação pós-operatória de ressecção do cólon maior eqüino: relato de caso / Jejunal strangulative obstruction as a post-operative complication of large colon ressection in a mare: case report

Em uma égua, submetida à laparotomia para correção de vólvulo do cólon maior, realizou-se enterectomia próximo ao ligamento cecocólico seguida de enteroanastomose término-terminal. Nas primeiras 24 horas do período pós-operatório, houve piora dos sinais clínicos, com ocorrência de dor, refluxo enterogástrico e agravamento do quadro de endotoxemia. Frente ao prognóstico desfavorável, optou-se pela eutanásia. Durante a necropsia, não foram constatadas falhas na enteroanastomose ou sinais de peritonite séptica. Observou-se encarceramento de uma alça de jejuno, que se apresentava justaposta à extremidade livre da prega cecocólica e comprimida entre o corpo do ceco e o cólon ventral direito remanescente, caracterizando obstrução do tipo estrangulada. Esse achado foi compatível com o agravamento do quadro clínico observado no pós-operatório. Essa ocorrência sugere a necessidade de uma adaptação na técnica de ressecção do cólon maior, de forma a reduzir o espaço cecocólico e evitar um possível encarceramento de alças de intestino delgado.

A mare subjected to laparotomy to treat a large colon volvulus had the large colon transected close to the cecocolic ligament followed by anastomosis using end-to-end technique. Despite intensive care, worsening of the clinical signs occurred during the first 24 hours after surgery including pain, enterogastric reflux and grievance of the endotoxemia symptoms. Euthanasia was performed. During necropsy, no signs of failure of the anastomosis and peritonitis were found but a strangulated segment of jejunum was observed adjacent to the cecocolic fold and compressed by the body of the cecum and the reminiscent rigth ventral colon. This finding was associated with the worsening of the clinical signs during the post-operative period. This report indicates that an adaptation in the large colon resection technique reducing the cecocolic space may be beneficial in avoiding such complication.

Predictors related to the occurrence of a measles epidemic in the city of São Paulo in 1997.

A matched case-control study was performed to identify risk factors for measles during an epidemic that occurred in 1997 in the city of São Paulo, in the Brazilian state of the same name. Measles cases from the city of São Paulo from 1 January 1997 to 15 August 1997 were included in the study. The criteria for case definition were age below 30 years, having received no measles vaccine 5-21 days before the onset of rash, and laboratory confirmation by IgM antibodies detection. From a bank of confirmed measles cases, 130 cases for each of five age ranges (under 1 year, 1-5 years, 6-20 years, 21-24 years, and 25-29 years) were picked at random according to a systematic criterion proportional to the number of cases in seven areas of the city. Data were collected through a home survey, and for each measles case studied two controls matched by age and place of residence were selected. The matched conditional logistic regression analysis for the potential risk factors from the univariate analysis showed that the best predictors for acquiring measles during the epidemic were: lack of measles vaccination, previous contact with a measles-like disease at home or on the job, having been born either outside the state of São Paulo or in a rural area, being employed, and spending time in a semiclosed institution, such as a nursery, day care center, or school. The risk factors were not homogeneous for the different age groups. The data in the present survey suggest that, in addition to lack of vaccination, other risk factors should be considered when planning a measles vaccination strategy for a developing country.

[Outbreak of malaria induced among users of injectable drugs]. / Surto de malária induzida entre usuários de drogas injetáveis.

Five cases of malaria were detected among cocaine users by the local health service in Bauru, a city with a population of 260,000, located 324 km from S. Paulo, Brazil, during the first three weeks of July 1990. Autochthonous malaria had not occurred in Bauru since 1978, and all the five cases denied having recently traveled to endemic areas. An extensive epidemiologic survey conducted from July 19 to September 13 revealed that the 5 cases were in fact part of a malaria outbreak among endovenous drug users. Moreover, at least 114 other people, who had in the last three months shared syringes and needles with one or more proved cases, were also involved in the outbreak. One hundred and two people were identified and interviewed orally. The examination of thick smears made from samples collected from 99 of them confirmed 21 cases of vivax malaria. Three people with negative blood smears had an indirect immunofluorescent assay positive to P. vivax antigen. Although the index case could not be discovered, the investigation suggested that one or more people who had recently traveled to the Amazon region might have introduced the disease. The control of the outbreak was achieved after offering treatment with chloroquine (10 tablets) to confirmed cases and contacts, followed by weekly suppressive chloroquine (2 tablets) until the last contact was detected. Malaria examination of 91 blood samples also revealed a high prevalence of hepatitis B virus infection (40%) and HIV infection (58%) among those involved in the outbreak. The strategy used to identify the cases and the contacts and the difficulties overcome in carrying it through are described.(ABSTRACT TRUNCATED AT 250 WORDS)