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Results for “TROPICAL CLIMATE”

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At least 37 records · Page 2Linked to original sources
PubMed1994

Tepid sponging to reduce temperature in febrile children in a tropical climate.

The effectiveness of tepid sponging, in addition to antipyretic medication, in the reduction of temperature in febrile children living in a tropical environment, was assessed in a prospective, randomized, open trial. Seventy-five children aged between 6 and 53 months who attended the casualty department of the Children's Hospital, Bangkok, Thailand, with fever (rectal temperature > or = 38.5 degrees C) of presumed viral origin were randomized to received either tepid sponging and oral paracetamol (sponged group) or paracetamol alone (control group). Rectal temperature and the occurrence of crying, irritability, and shivering were recorded over the following 2 hours. A greater and more rapid fall in mean rectal temperature occurred in the sponged group than in the control group. Temperature fell below 38.5 degrees C sooner in children in the sponged group than in control children (P < 0.001). At 60 minutes, 38 (95.0%) of the controls still had a temperature of 38.5 degrees C or greater, compared with only 15 children (42.9%) in the sponged group (P < 1 x 10(-5). Crying was associated with sponging, but shivering and irritability occurred in only one child who was being sponged. It is concluded that tepid sponging, in addition to antipyretic medication, is clearly more effective than antipyretic medication alone in reducing temperature in febrile children living in a tropical climate.

Acetaminophen↗
PubMed2005

Performance analysis of anoxic selector in upgrading activated sludge process in tropical climate.

The paper describes and analyses the performance of anoxic selectors in upgrading activated sludge process in a municipal wastewater treatment plant under tropical climate, where poor sludge settleability is a problem due to elevated temperature. Site monitoring and laboratory experiment were conducted to study the denitrification, sludge settleability, kinetics, mass balance, pH and alkalinity variation in the system. The sludge settleability measured in Sludge Volume Index (SVI) was observed to improve with the increasing degree of denitrification in the anoxic selector. Under well-developed stable state, an average SVI value of 136 ml/g was achieved, which was significantly lower than the value of 250 ml/g before the application of anoxic selector. The specific reaction rates for denitrification and nitrification at 30 degrees C were 0.06 mg NO3-N/mg MLSS day and 0.08 mg NH4-N/mg MLSS day, respectively. The overall efficiencies of nitrification and denitrification were 86 percent and 55.4 percent, respectively, with an alkalinity recovery ratio of 15.4 percent. 32 percent of total COD removed was used up as electron donor in the denitrification process. However, due to absence of the internal Mixed Liquor Recirculation (MLR), a higher degree of denitrification occurred in the secondary sedimentation tank than in the anoxic zone. Issues for further studies are also discussed.

Ammonia↗
PubMed2001

[Performance and simulation of intermittent decanted extended aeration treatment plants in a tropical climate].

The paper discusses the design and performance of package sewage treatment plants using the Intermittently Decanted Extended Aeration Process (IDEA-Process) in a tropical climate. This hybrid SBR process has been developed overcome traditional drawbacks associated with the SBR process, such as high Sludge Volume Index, high weir loading rate for decanting, and the need to achieve a better effluent quality, especially in terms of nutrient removal. Three domestic sewage plants in Thailand has been selected for field-testing and results of analyses are presented. The average measured biological removal efficiencies in terms of BOD removal and COD removal are about 95.5% and 90% respectively, and the average total nitrogen removal efficiency is about 90%. A computer model is used to study the performance of IDEA-processes compared to results from laboratory tests. The model experience gained through this research are discussed regarding the limitations of computer models such as ASM 1 (Activated Sludge Model n degrees 1) applied to the IDEA-Process in order to develop a new computer model suitable for design and operation of package treatment plant using IDEA-Process Technology in the future.

Bioreactors↗
PubMed2004

A comparative study of Cyperus papyrus and Miscanthidium violaceum-based constructed wetlands for wastewater treatment in a tropical climate.

The treatment efficiencies of constructed wetlands containing Cyperus papyrus L. (papyrus) and Miscanthidium violaceum (K. Schum.) Robyns (synonymous with Miscanthus violaceum (K. Schum) Pilg.) were investigated in a tropical climate (Kampala, Uganda). Papyrus showed higher ammonium-nitrogen and total reactive phosphorus (TRP) removal (75.3% and 83.2%) than Miscanthidium (61.5% and 48.4%) and unplanted controls (27.9% ammonium-nitrogen). No TRP removal was detected in control effluent. Nutrients (N and P) were significantly higher (p<0.015) in papyrus than Miscanthidium plant tissues. Plant uptake and storage was the major factor responsible for N and P removal in treatment line 2 (papyrus) where it contributed 69.5% N and 88.8% P of the total N and P removed. It however accounted for only 15.8% N and 30.7% P of the total N and P removed by treatment line 3 (Miscanthidium violaceum). In addition, papyrus exhibited a significantly larger (p=0.000) number of adventitious roots than Miscanthidium. Nitrifying bacteria attached to papyrus (2.15 x 10(6)+/-1.53 x 10(5) MPN/g DW) and Miscanthidium roots (1.30 x 10(4)+/-8.83 x 10(2) MPN/g DW) and the corresponding nitrification activities were consistent with this finding. Epiphytic nitrifiers appeared more important for total nitrification than those in peat or suspended in water. Papyrus root structures provided more microbial attachment sites, sufficient wastewater residence time, trapping and settlement of suspended particles, surface area for pollutant adsorption, uptake, assimilation in plant tissues and oxygen for organic and inorganic matter oxidation in the rhizosphere, accounting for its high treatment efficiency.

Biodegradation, Environmental↗
PubMed1988

Seasonal changes in circadian rhythms of body temperatures in humans living in a dry tropical climate.

Seven volunteers (3 females and 4 males; 3 Caucasians and 4 Africans) participated in two 24 h sessions during the cool dry (CD) and the hot dry (HD) seasons of the sahelian tropical climate. Body temperatures were taken on portable cassette recorders for 24 h. Rectal (Tre) and mean skin (Tsk) temperatures decreased in the HD compared to the CD conditions, meeting one of the criteria for adaptation to heat. No ethnic differences in thermal responses were found. Males and females differed in their body temperature rhythms and in their reactions to heat. Body temperatures were higher in females than in males. Males reacted to heat with a decrease in Tre, without change in the Tre-Tsk gradient. Females showed a decrease in both Tre and Tsk, more marked for Tsk, with an increase in the Tre-Tsk gradient. It was concluded that males showed seasonal acclimatization to heat via a decrease in metabolism confirmed by a decrease in plasma levels of thyroid stimulating hormone (TSH) in the HD condition. Females showed a mixed metabolic and thermolytic type of acclimatization, with an absence of variation in plasma TSH levels. In conclusion, the steady rise in temperature between the CD and HD conditions was sufficient to trigger an acclimatization to heat similar in Caucasian and African subjects, although exposure to the external climate differed widely.

Acclimatization↗
PubMed1983

Identification of strains isolated as total and fecal coliforms and comparison of both groups as indicators of fecal pollution in tropical climates.

This study was undertaken to better characterize the groups of total coliforms (TC) and fecal coliforms (FC) and to evaluate both groups as indicators of fecal contamination of drinking well water in a tropical climate (The Ivory Coast, West Africa). Isolated colonies obtained as TC or FC on membrane filters were identified using the API-20E system. From the well water samples, 58 golden-green colonies with a metallic sheen isolated on Endo medium (TC) were identified as Escherichia coli (55%), Enterobacter (26%), Klebsiella (14%), Proteus (3%), and Citrobacter (2%). Among 132 colonies isolated on Endo medium as non-TC (not showing the characteristic golden metallic sheen), 10% were identified as E. coli. The 196 blue colonies isolated on M-FC medium at 44.5 degrees C (FC) were identified as E. coli (66%), Klebsiella (12%), Enterobacter (10%), Citrobacter (5%), Salmonella (3%), Serratia (3%), Proteus (2%), and Yersinia (0.5%). Among 24 nonblue colonies on M-FC medium, none were identified as E. coli. Of the colonies isolated from human feces, E. coli represents 92% of the TC and 89% of the FC. Although these results are limited, they tend to confirm the greater specificity of the fecal coliform technique over that of total coliform for the detection of fecal contamination of untreated well water. From the results presented here and the observations of other workers, it is suggested that the use of FC instead of TC should be considered as the method of choice for determining drinking water pollution of untreated groundwater supplies.

Enterobacteriaceae↗
PubMed2002

Short report: seasonal pattern of respiratory syncytial virus in a region with a tropical climate in southeastern Brazil.

Among acute respiratory infections (ARIs), respiratory syncytial virus (RSV) is an important pathogen, especially in infants and preschool children. This study focused on RSV epidemiology in a region of southeastern Brazil with a tropical climate. A total of 406 nasopharyngeal secretion samples were taken from children less than five years of age with ARIs. Of these, 114 (28%) were RSV-positive. These samples were found in all age groups, but showed a higher prevalence in newborns. Infection with RSV was identified in 10 of the 12 months of the study period, but the majority (88.5%) of cases occurred from late summer to mid-fall.

Age Factors↗
PubMed2003

Molecular marker dissection of rice (Oryza sativa L.) plant architecture under temperate and tropical climates.

Rice ( Oryza sativa L.) plants develop vertically with shoot elongation and horizontally with tillering. The purpose of this study was to identify and characterize genomic regions influencing the rice plant architecture by quantitative trait locus (QTL) analysis for the component traits: culm length (CL), panicle length (PnL), panicle number (PnN) and tiller number (TN). For this QTL analysis, 191 recombinant inbred lines (F(7)) derived from a cross of Milyang 23 (M23) and Akihikari (AK) were grown in 1995, 1996 and 1997 (May-Oct) in Joetsu, Japan (temperate climate), and in the 2000 dry season (Jan-Apr), the 2000 wet season (Jun-Oct) and the 2001 dry season in Los Baños, The Philippines (tropical climate). Results showed that rice plant architecture was influenced by 19 genomic regions categorized into five groups. In Group I, two regions (on chrs. 6 and 11) affected shoot elongation (CL and PnL) and tillering (PnN and TN) in opposite directions more significantly in Los Baños than in Joetsu. In Group II, two regions (chrs. 3 and 12) affected shoot elongation, whereas in Group III, five regions [chrs. 1 (two), 2, 3 and 9] affected only culm length (CL). Expressions of four regions of Group III were influenced by either tropical or temperate environments. In Group IV, seven regions (chrs. 1, 2, 4, 5, 6, 8 and 9) controlled panicle development (PnN or PnL), and in Group V, three regions (chrs. 1, 2 and 3) regulated tillering (PnN or TN). Characterizing these 19 genomic regions provided a detailed analysis of rice plant architecture with emphasis on the multiple effect and environmental responsive regions.

Genetic Markers↗
PubMed2003

Treatment of agricultural wastewater in two experimental combined constructed wetland systems in a tropical climate.

Two designs of experimental combined constructed wetland systems were constructed: vegetated (Scirpus grossus Linn) subsurface horizontal flow bed followed by a vegetated vertical flow bed and a vegetated vertical flow bed over an unvegetated horizontal flow sand bed. The systems were used to compare the nitrification/denitrification efficiency in a tropical climate which has temperatures above an average of 25 degrees C throughout the year. The effluent from a biogas digester of pig farm wastewater with TKN and COD concentrations of approximately 400 and 1,000 mg/L was fed every 4 hours intermittently. The effluent was recycled to the system with the ratio of 1:1 and the hydraulic loading rate was increased from 3 to 6 and 12 cm/d including recycled water. At higher hydraulic loading rates, nitrogen COD and BOD removal efficiencies were lower. The SS, TP and fecal coliform bacteria removal efficiencies were not clearly affected by the high hydraulic loading or the different layout of the system. Nitrogen uptake by plants was very low in relation to the nitrogen loading of the systems. In general, the removal efficiencies of both types were comparable but the system with a vertical flow over horizontal flow sand bed is more suitable for sites with limited land area, although its construction can be more difficult than the system with horizontal flow followed by a vertical flow bed.

Agriculture↗
PubMed1996

Humidification of oxygen with unheated humidifiers in tropical climates.

In developing countries, oxygen therapy in hospitals is frequently humidified with unheated bubble-through humidifiers. We assessed the efficacy of humidification under such circumstances. The water temperature in the humidifier and the ambient air temperature were measured and compared to the oxygen flow rate. It was calculated that oxygen was cooled in the humidifier by 6.12 degrees C (95% CI: 5.88; 6.35) per liter of flow for flow rates up to 2 l/min. Using the average temperatures on the hospital ward in January and August, and the WHO-recommended flow rates of 0.5 l/min and 1 l/min, the relative humidity of the oxygen delivered to a child was estimated to be between 34% and 56%. We conclude that unheated bubble-through humidifiers achieve low humidity in oxygen in tropical climates. Some of the complications associated with the use of nasopharyngeal catheters for the delivery of oxygen might be explained by this, as oxygen of low humidity and temperature is delivered directly into the posterior nasopharynx.

Acute Disease↗
PubMed2004

The use of hormonal treatments to improve reproductive performance of anestrous beef cattle in tropical climates.

Most of the world's bovine herd is found in tropical regions. Bos indicus predominates, due to their adaptation to the climate and management conditions. Anestrous is the main factor that negatively affects reproductive performance of animals bred in these regions of the globe. Several factors affect postpartum anestrous, including suckling and maternal-offspring bond, and pre- and postpartum nutritional status. The short duration of estrus and the tendency to show estrus during the night, greatly affect the efficiency of artificial insemination (AI) programs in B. indicus cattle managed in tropical areas. Several restricted suckling or weaning procedures (temporary or permanent), and hormonal treatments have been used to induce ovulation and cyclicity in postpartum cows. Most hormonal treatments are based on progesterone/progestogen (P4) releasing devices associated with estradiol benzoate (EB), or a combination of GnRH/PGF(2alpha)/GnRH (Ovsynch). Treatments with GnRH/PGF(2alpha)/GnRH has presented inconsistent results, probably due to the variable number of cows in anestrous. Treatments using P4 devices and EB have resulted in apparently more consistent results than Ovsynch programs in B. indicus cattle; however, pregnancy rates are low in herds presenting high anestrous rates and moderate to low body condition. The addition of an eCG treatment at the time of device removal, which increased plasma progesterone concentrations and pregnancy rates in anestrous postpartum suckled B. indicus cows, may be useful to improve reproductive performance of beef cattle in tropical climates.

Anestrus↗