33 research outputs found

    The Effects of Fire on Organic Functional Groups of Peat in Relation to Water Content

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    The aim of this research was to study the decline of organic functional group through the process of burning in peat. In addition, this study was also to examine the relationship between water content in peat and organic functional group after combustion (burning).  Peat drying was conducted in an oven at a temperature of 75°C with the interval of 0, 1, 2, 3, 4, 5 and 6 hours.  Each time interval had three replicates within two sets of experiments so that the total number of samples were 42 (experimental units).  Variables measured were moisture content, total acidity, COOH groups, and OH-phenolate.  The relationship between the water content with total acidity, COOH groups and OH-phenolate were determined by the equation y = bx + a.  The results showed that the relationship between the water content with organic functional group was linear.  While the relationship between peat water content with organic functional group after burning was irregular, although water levels through the process of burning have been greatly reduced. Keywords: Burning peat; organic functional groups; water content [How to Cite: Said R, FH Yusran, A Haris and S Asmawi. 2014. The Effects of Fire on Organic Functional Groups of Peat in Relation to Water Content. J Trop Soils 19: 143-149. Doi: 10.5400/jts.2014.19.3.143]  [Permalink/DOI: www.dx.doi.org/10.5400/jts.2014.19.3.143]  &nbsp

    Evaluation of a Rapid Dipstick (Crystal VC) for the Diagnosis of Cholera in Zanzibar and a Comparison with Previous Studies

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    BackgroundThe gold standard for the diagnosis of cholera is stool culture, but this requires laboratory facilities and takes at least 24 hours. A rapid diagnostic test (RDT) that can be used by minimally trained staff at treatment centers could potentially improve the reporting and management of cholera outbreaks.MethodsWe evaluated the Crystal VC™ RDT under field conditions in Zanzibar in 2009. Patients presenting to treatment centers with watery diarrhea provided a stool sample for rapid diagnostic testing. Results were compared to stool culture performed in a reference laboratory. We assessed the overall performance of the RDT and evaluated whether previous intake of antibiotics, intravenous fluids, location of testing, and skill level of the technician affected the RDT results.ResultsWe included stool samples from 624 patients. Compared to culture, the overall sensitivity of the RDT was 93.1% (95%CI: 88.7 to 96.2%), specificity was 49.2% (95%CI: 44.3 to 54.1%), the positive predictive value was 47.0% (95%CI: 42.1 to 52.0%) and the negative predictive value was 93.6% (95%CI: 89.6 to 96.5%). The overall false positivity rate was 50.8% (213/419); fieldworkers frequently misread very faint test lines as positive.ConclusionThe observed sensitivity of the Crystal VC RDT evaluated was similar compared to earlier versions, while specificity was poorer. The current version of the RDT could potentially be used as a screening tool in the field. Because of the high proportion of false positive results when field workers test stool specimens, positive results will need to be confirmed with stool culture

    The Burden of Invasive Bacterial Infections in Pemba, Zanzibar

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    BACKGROUND: We conducted a surveillance study to determine the leading causes of bloodstream infection in febrile patients seeking treatment at three district hospitals in Pemba Island, Zanzibar, Tanzania, an area with low malaria transmission. METHODS: All patients above two months of age presenting to hospital with fever were screened, and blood was collected for microbiologic culture and malaria testing. Bacterial sepsis and malaria crude incidence rates were calculated for a one-year period and were adjusted for study participation and diagnostic sensitivity of blood culture. RESULTS: Blood culture was performed on 2,209 patients. Among them, 166 (8%) samples yielded bacterial growth; 87 (4%) were considered as likely contaminants; and 79 (4%) as pathogenic bacteria. The most frequent pathogenic bacteria isolated were Salmonella Typhi (n = 46; 58%), followed by Streptococcus pneumoniae (n = 12; 15%). The crude bacteremia rate was 6/100,000 but when adjusted for potentially missed cases the rate may be as high as 163/100,000. Crude and adjusted rates for S. Typhi infections and malaria were 4 and 110/100,000 and 4 and 47/100,000, respectively. Twenty three (51%), 22 (49%) and 22 (49%) of the S. Typhi isolates were found to be resistant toward ampicillin, chloramphenicol and cotrimoxazole, respectively. Multidrug resistance (MDR) against the three antimicrobials was detected in 42% of the isolates. CONCLUSIONS: In the presence of very low malaria incidence we found high rates of S. Typhi and S. pneumoniae infections on Pemba Island, Zanzibar. Preventive measures such as vaccination could reduce the febrile disease burden
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