The study of environmental chemical contaminants and their toxicological effects has changed dramatically over the last 50 years. Initially studies concentrated on trying to identify what contaminants were actually present and to develop quantitative methods to determine the concentrations (total) present. Health impacts were often investigated independently in medical research centres. With improving analytical techniques, studies of the speciation of contamina nts began and the specific forms that were creating the major problems were gradually identified. Continuing improvements in analytical chemistry, together with a move towards more integrated and multidisciplinary research now sees chemists, biologists, toxicologists and health researchers working closely in teams to identify the specific agents of major concern and their pathways, transformations and mode of action. These changes in approach are reviewed. Issues that still require significant research such as cumulative impacts are also discussed.
{"title":"Evolution of Chemical Contaminant and Toxicology Studies, Part 1 - An Overview","authors":"D. Jolley, G. O'Brien, J. Morrison","doi":"10.1071/SP03001","DOIUrl":"https://doi.org/10.1071/SP03001","url":null,"abstract":"The study of environmental chemical contaminants and their toxicological effects has changed dramatically over the last 50 years. Initially studies concentrated on trying to identify what contaminants were actually present and to develop quantitative methods to determine the concentrations (total) present. Health impacts were often investigated independently in medical research centres. With improving analytical techniques, studies of the speciation of contamina nts began and the specific forms that were creating the major problems were gradually identified. Continuing improvements in analytical chemistry, together with a move towards more integrated and multidisciplinary research now sees chemists, biologists, toxicologists and health researchers working closely in teams to identify the specific agents of major concern and their pathways, transformations and mode of action. These changes in approach are reviewed. Issues that still require significant research such as cumulative impacts are also discussed.","PeriodicalId":148381,"journal":{"name":"The South Pacific Journal of Natural and Applied Sciences","volume":"157 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127363174","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lightning measurements have been extensively utilised by power companies, metereological offices as well as by the scientific community in general. As opposed to the Intra-Cloud (IC) discharge, the Cloud – to – Ground (CG) lightning stroke $ a major safety hazard. In CG lightning stoke, the stepped leader decending from the base of a thundercloud triggers the first return stroke. This stroke is responsible for most of the charge transfer within few tens of microseconds causing a current of tens of kA. In this report, we present a novel CG stroke location accuracy of ≈2km.
{"title":"Cloud-to-Ground lightning location using TOGA of sferics","authors":"V. Ramachandran, Sushi I Kumar, Anol Kishore","doi":"10.1071/SP03013","DOIUrl":"https://doi.org/10.1071/SP03013","url":null,"abstract":"Lightning measurements have been extensively utilised by power companies, metereological offices as well as by the scientific community in general. As opposed to the Intra-Cloud (IC) discharge, the Cloud – to – Ground (CG) lightning stroke $ a major safety hazard. In CG lightning stoke, the stepped leader decending from the base of a thundercloud triggers the first return stroke. This stroke is responsible for most of the charge transfer within few tens of microseconds causing a current of tens of kA. In this report, we present a novel CG stroke location accuracy of ≈2km.","PeriodicalId":148381,"journal":{"name":"The South Pacific Journal of Natural and Applied Sciences","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117014999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The survival of Escherichia coli in tropical estuarine water has been studied under controlled laboratory conditions using microcosms. The survival has been assessed in terms of various self purifying factors of the natural waters such as biological, chemical and physical factors. The biological factors considered included competition from other microorganisms, predation by protozoa and coliphages. The suitability of the chemical composition of estuarine water has been studied under chemical factors and negative impact of sunlight has been studied under physical factors. The results revealed that sunlight exerted maximum negative impact, followed by biotic factors contained in the estuarine water. However, the chemical composition of the estuarine water is found to be suitable for the growth and survival of E. coli. The injury exerted by each of the above factors was also evaluated by using a selective and non-selective medium in conjunction. It was found that sunlight resulted in 100% injury of the cells as the cells failed to develop in a selective medium. While, sunlight resulted in the extinction of 90% of the E. coli cells within the first two hours of exposure, biotic factors took nearly 24 hours to remove the same amount of population.
{"title":"Survival of Escherichia coli in a tropical estuary","authors":"A. Chandran, A. Hatha","doi":"10.1071/SP03008","DOIUrl":"https://doi.org/10.1071/SP03008","url":null,"abstract":"The survival of Escherichia coli in tropical estuarine water has been studied under controlled laboratory conditions using microcosms. The survival has been assessed in terms of various self purifying factors of the natural waters such as biological, chemical and physical factors. The biological factors considered included competition from other microorganisms, predation by protozoa and coliphages. The suitability of the chemical composition of estuarine water has been studied under chemical factors and negative impact of sunlight has been studied under physical factors. The results revealed that sunlight exerted maximum negative impact, followed by biotic factors contained in the estuarine water. However, the chemical composition of the estuarine water is found to be suitable for the growth and survival of E. coli. The injury exerted by each of the above factors was also evaluated by using a selective and non-selective medium in conjunction. It was found that sunlight resulted in 100% injury of the cells as the cells failed to develop in a selective medium. While, sunlight resulted in the extinction of 90% of the E. coli cells within the first two hours of exposure, biotic factors took nearly 24 hours to remove the same amount of population.","PeriodicalId":148381,"journal":{"name":"The South Pacific Journal of Natural and Applied Sciences","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124349453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We use a continuous age-structured model of McKendrick-von-Foerster type to derive a two-age groups HIV/AIDS epidemic model. In the analysis of the model, keen interest is put on the role of vertical transmission in the dynamics of the spread of the epidemic. The model is analysed in two scenarios: the case when the force of infection is a constant and the case when we have it as a mass action. In the first case, the only possible equilibrium is the endemic equilibrium. In this situation, we show that if all babies born to infected mothers are HIV-free we have the basic reproductive number R0 = 0 and as such the epidemic will die out. In the second case, we show that both the disease-free and endemic equilibrium points exist. We also derive conditions for their stability.
{"title":"Modelling the effect of vertical transmission in the dynamics of HIV/AIDS in an age-structured population","authors":"J. Mugisha, L. Luboobi","doi":"10.1071/SP03016","DOIUrl":"https://doi.org/10.1071/SP03016","url":null,"abstract":"We use a continuous age-structured model of McKendrick-von-Foerster type to derive a two-age groups HIV/AIDS epidemic model. In the analysis of the model, keen interest is put on the role of vertical transmission in the dynamics of the spread of the epidemic. The model is analysed in two scenarios: the case when the force of infection is a constant and the case when we have it as a mass action. In the first case, the only possible equilibrium is the endemic equilibrium. In this situation, we show that if all babies born to infected mothers are HIV-free we have the basic reproductive number R0 = 0 and as such the epidemic will die out. In the second case, we show that both the disease-free and endemic equilibrium points exist. We also derive conditions for their stability.","PeriodicalId":148381,"journal":{"name":"The South Pacific Journal of Natural and Applied Sciences","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124981502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nutrient (nitrate and phosphate) levels potentially damaging to coral reefs have been detected at several sites along the Coral Coast of Viti Levu, Fiji. Nutrient concentrations were determined using standard techniques on an autoanalyser capable of measuring to sub-micromolar levels. The mean nitrate level for 34 seawater samples was 1.69 mM and the mean phosphate level was 0.21 mM which exceeded levels considered to be harmful to coral reef ecosystems (>1.0 mM N, >0.1 mM P). It is proposed that these elevated nutrient levels coupled with overfishing of herbivore species have contributed to the recent widespread growth of macro -algae species along this coast. Nutrient levels were highest at sites located near hotels and other populated sites. At sites not significantly influenced by human activity, levels were comparable to that of non-polluted sites elsewhere in Fiji. Concentrations of nutrients in rivers along the coast were generally higher than in seawater. Urgent action is needed at community, regional and government levels to try and reduce the nutrient inputs to this coast.
在斐济维提岛珊瑚海岸的几个地点检测到可能对珊瑚礁造成损害的营养物质(硝酸盐和磷酸盐)水平。在自动分析仪上使用标准技术测定营养浓度，能够测量到亚微摩尔水平。34个海水样本的平均硝酸盐含量为1.69 mM，平均磷酸盐含量为0.21 mM，超过了对珊瑚礁生态系统有害的水平(>1.0 mM N， >0.1 mM P)。这些营养水平的升高加上草食性物种的过度捕捞是近年来大型藻类物种在该海岸广泛生长的原因。在酒店和其他人口密集的地点附近，营养水平最高。在未受人类活动显著影响的场址，其水平与斐济其他地方未受污染的场址相当。沿岸河流的营养物质浓度普遍高于海水。需要在社区、地区和政府层面采取紧急行动，努力减少流入这一海岸的营养物质。
{"title":"Nutrient levels in sea and river water along the Coral Coast of Viti Levu, Fiji","authors":"L. Mosley, W. Aalbersberg","doi":"10.1071/SP03007","DOIUrl":"https://doi.org/10.1071/SP03007","url":null,"abstract":"Nutrient (nitrate and phosphate) levels potentially damaging to coral reefs have been detected at several sites along the Coral Coast of Viti Levu, Fiji. Nutrient concentrations were determined using standard techniques on an autoanalyser capable of measuring to sub-micromolar levels. The mean nitrate level for 34 seawater samples was 1.69 mM and the mean phosphate level was 0.21 mM which exceeded levels considered to be harmful to coral reef ecosystems (>1.0 mM N, >0.1 mM P). It is proposed that these elevated nutrient levels coupled with overfishing of herbivore species have contributed to the recent widespread growth of macro -algae species along this coast. Nutrient levels were highest at sites located near hotels and other populated sites. At sites not significantly influenced by human activity, levels were comparable to that of non-polluted sites elsewhere in Fiji. Concentrations of nutrients in rivers along the coast were generally higher than in seawater. Urgent action is needed at community, regional and government levels to try and reduce the nutrient inputs to this coast.","PeriodicalId":148381,"journal":{"name":"The South Pacific Journal of Natural and Applied Sciences","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131872915","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study we have developed an in house capacity at the Chemistry Department, the University of the South Pacific, to analyze methane in ambient air to a precision of 1.5% using a custom converted Gas Chromatograph with FID detector. The technical support to develop this capacity was provided by our overseas partner, National Institute of Water and Atmospheric Research (NIWA). The air samples were collected from known sources of methane such as the digester at the sewage treatment plant, rubbish dump, wetlands, sugar cane burning in the western side of Viti Levu, geothermal emission in Vanua Levu, rice farms and cattle farms from September 2001 to June 2002 and were analyzed. Through inter-laboratory measurements involving NIWA a mean drift of 0.8% was obtained. The methane concentration in the ambient air has a seasonal cycle with a minimum during late January and a maximum during the July to August period. The digester at the sewage plant recorded the maximum concentration of approximately 70 ppmv followed by Lami rubbish dump with values ranging from 4.37 – 13.35 ppmv. The data from cattle farms, wetlands, rice farms and hot springs recorded emissions in the range of 2.00 – 5.11 ppmv, 1.85 – 4.25 ppmv, 1.77 – 2.62 ppmv and 2.06 – 1.90 ppmv respectively.
{"title":"Methane Concentration in Fiji Air: A Study of its Emission Trends and Source Strengths","authors":"F. Mani, K. Koshy, M. Maata","doi":"10.1071/SP03004","DOIUrl":"https://doi.org/10.1071/SP03004","url":null,"abstract":"In this study we have developed an in house capacity at the Chemistry Department, the University of the South Pacific, to analyze methane in ambient air to a precision of 1.5% using a custom converted Gas Chromatograph with FID detector. The technical support to develop this capacity was provided by our overseas partner, National Institute of Water and Atmospheric Research (NIWA). The air samples were collected from known sources of methane such as the digester at the sewage treatment plant, rubbish dump, wetlands, sugar cane burning in the western side of Viti Levu, geothermal emission in Vanua Levu, rice farms and cattle farms from September 2001 to June 2002 and were analyzed. Through inter-laboratory measurements involving NIWA a mean drift of 0.8% was obtained. The methane concentration in the ambient air has a seasonal cycle with a minimum during late January and a maximum during the July to August period. The digester at the sewage plant recorded the maximum concentration of approximately 70 ppmv followed by Lami rubbish dump with values ranging from 4.37 – 13.35 ppmv. The data from cattle farms, wetlands, rice farms and hot springs recorded emissions in the range of 2.00 – 5.11 ppmv, 1.85 – 4.25 ppmv, 1.77 – 2.62 ppmv and 2.06 – 1.90 ppmv respectively.","PeriodicalId":148381,"journal":{"name":"The South Pacific Journal of Natural and Applied Sciences","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129593024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
As the second of a two part series discussing the evolution of the field of environmental toxicology, this paper presents two case studies: selenium and arsenic. Developments over several decades in the understanding of the behaviour of arsenic and selenium in different chemical forms in various compartments of the environment are discussed. Selenium was initially thought to be toxic, but later investigations showed it to be an essential micronutrient with a variety of biochemical functions, and, importantly, that there is a very narrow gap between the essential and the toxic body burden. Arsenic, on the other hand, has not yet had an essential role established, but enjoys an interesting and notorious history of usage. Arsenic contamination of the drinking water supplies for many millions of people has been a major catalyst for much research into understanding arsenic chemistry in aquifer systems and also arsenic metabolism and toxicity. The relationships between chemical form, bioavailability, toxicity and metabolism of these two semi-metals are being established, especially with use of sophisticated and sensitive analytical instrumentation and biochemical techniques.
{"title":"Evolution of chemical contaminant and toxicology studies, part 2 - case studies of Selenium and Arsenic","authors":"G. O'Brien, D. Jolley, J. Morrison","doi":"10.1071/SP03002","DOIUrl":"https://doi.org/10.1071/SP03002","url":null,"abstract":"As the second of a two part series discussing the evolution of the field of environmental toxicology, this paper presents two case studies: selenium and arsenic. Developments over several decades in the understanding of the behaviour of arsenic and selenium in different chemical forms in various compartments of the environment are discussed. Selenium was initially thought to be toxic, but later investigations showed it to be an essential micronutrient with a variety of biochemical functions, and, importantly, that there is a very narrow gap between the essential and the toxic body burden. Arsenic, on the other hand, has not yet had an essential role established, but enjoys an interesting and notorious history of usage. Arsenic contamination of the drinking water supplies for many millions of people has been a major catalyst for much research into understanding arsenic chemistry in aquifer systems and also arsenic metabolism and toxicity. The relationships between chemical form, bioavailability, toxicity and metabolism of these two semi-metals are being established, especially with use of sophisticated and sensitive analytical instrumentation and biochemical techniques.","PeriodicalId":148381,"journal":{"name":"The South Pacific Journal of Natural and Applied Sciences","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122385740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A high-volume air sampler and a high-resolution gamma-ray spectrometer have been used during the period 1999-2000 at the University of the South Pacific to measure the activity of 7Be in the surface air at Suva, the capital city of Fiji. The measurements indicate that the average concentration of 7Be in surface air is about 1.6 mBq m-3, which agrees closely with the corresponding values reported for other Pacific islands in the region. 7Be shows a significant correlation with nitrate in the atmosphere. This could imply long-range transport of anthropogenically-derived continental material to Fiji or the intrusion of nitrogen species from the stratosphere to surface air.
{"title":"Concentration of 7Be in surface air at Suva, Fiji","authors":"S. Garimella, K. Koshy, Shusendra Singh","doi":"10.1071/SP03003","DOIUrl":"https://doi.org/10.1071/SP03003","url":null,"abstract":"A high-volume air sampler and a high-resolution gamma-ray spectrometer have been used during the period 1999-2000 at the University of the South Pacific to measure the activity of 7Be in the surface air at Suva, the capital city of Fiji. The measurements indicate that the average concentration of 7Be in surface air is about 1.6 mBq m-3, which agrees closely with the corresponding values reported for other Pacific islands in the region. 7Be shows a significant correlation with nitrate in the atmosphere. This could imply long-range transport of anthropogenically-derived continental material to Fiji or the intrusion of nitrogen species from the stratosphere to surface air.","PeriodicalId":148381,"journal":{"name":"The South Pacific Journal of Natural and Applied Sciences","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125259055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Deciding on university student disciplinary cases against stipulated rules and case facts an interesting problem for artificial intelligence. Reasoning with fuzzy rules and facts adds to the problem complexity. This paper discusses the various characteristics of the problem and presents a design and an implementation of a prototype that is modeled as a fuzzy expert system. Some test results are presented and the experience gained from the project is discussed. Some future work is also suggested to further strengthen the prototype to include a formal case specification and interaction language, and the possible drawing and use of relevant information from a knowledge base of previous cases.
{"title":"A fuzzy legal reasoner for university decision support","authors":"D. Sharma, S. Behari","doi":"10.1071/SP03014","DOIUrl":"https://doi.org/10.1071/SP03014","url":null,"abstract":"Deciding on university student disciplinary cases against stipulated rules and case facts an interesting problem for artificial intelligence. Reasoning with fuzzy rules and facts adds to the problem complexity. This paper discusses the various characteristics of the problem and presents a design and an implementation of a prototype that is modeled as a fuzzy expert system. Some test results are presented and the experience gained from the project is discussed. Some future work is also suggested to further strengthen the prototype to include a formal case specification and interaction language, and the possible drawing and use of relevant information from a knowledge base of previous cases.","PeriodicalId":148381,"journal":{"name":"The South Pacific Journal of Natural and Applied Sciences","volume":"83 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115761408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Seeds from a toxic variety of Jatropha curcas (Capo Verde, Nicaragua) were processed, defatted and ground to obtain the meal. The meal was subjected to heat and 14 different chemical treatments to detoxify the meal of lectin and phorbolesters. Heat treatment inactivated lectin, but not phorbolester. One of the treatments reduced phorbolesters to a tolerable level of 0.09 mg/g. The treated meals with other ingredients were used in diets to assess acceptance and nutritive value of detoxified Jatropha curcas meal in two experiments. Experiments 1 and 2 had twelve (12) male weanling rats each, Sprague Dawley strain, 28-30 days old, pre-experimental average body weights of 8379±7.2 and 84.6±6.4 g, respectively. They were divided into three groups according to body weight and fed casein diet (control) and two diets in which Jatropha curcas was the protein source. In experiment 1, the rats accepted diet 1, but did not fully accept diet 2. Food intake, growth rate, protein efficiency ratio (PER) and food transformation index (T1) were significantly better (P<0.05) in diet 1 than in the casein and diet 2. In experiment 2, casein diet was better (P<0.05) in food intake, growth rate, PER and TI than diets 1 and 2. Food intake with Jatropha meal was significantly reduced and the rats had drastic body weight loss (P<0.05) and this might be due to the presence of phorbolesters in the diets. Generally, the presence of phorbolesters in food has significant effect on its acceptance. Jatropha meal obtained from treatment 3 had a crude protein (CP) content of 68%, far higher than the CP content of most oilseed meals (soyabean). This treatment seems a better method of detoxifying Jatropha curcas meal for livestock but in economic terms it is expensive to produce a meal from it.
{"title":"Detoxification of a toxic variety of Jatropha curcas using heat and chemical treatments, and preliminary nutritional evaluation with rats","authors":"E. M. Aregheore, K. Becker, H. Makkar","doi":"10.1071/SP03010","DOIUrl":"https://doi.org/10.1071/SP03010","url":null,"abstract":"Seeds from a toxic variety of Jatropha curcas (Capo Verde, Nicaragua) were processed, defatted and ground to obtain the meal. The meal was subjected to heat and 14 different chemical treatments to detoxify the meal of lectin and phorbolesters. Heat treatment inactivated lectin, but not phorbolester. One of the treatments reduced phorbolesters to a tolerable level of 0.09 mg/g. The treated meals with other ingredients were used in diets to assess acceptance and nutritive value of detoxified Jatropha curcas meal in two experiments. Experiments 1 and 2 had twelve (12) male weanling rats each, Sprague Dawley strain, 28-30 days old, pre-experimental average body weights of 8379±7.2 and 84.6±6.4 g, respectively. They were divided into three groups according to body weight and fed casein diet (control) and two diets in which Jatropha curcas was the protein source. In experiment 1, the rats accepted diet 1, but did not fully accept diet 2. Food intake, growth rate, protein efficiency ratio (PER) and food transformation index (T1) were significantly better (P<0.05) in diet 1 than in the casein and diet 2. In experiment 2, casein diet was better (P<0.05) in food intake, growth rate, PER and TI than diets 1 and 2. Food intake with Jatropha meal was significantly reduced and the rats had drastic body weight loss (P<0.05) and this might be due to the presence of phorbolesters in the diets. Generally, the presence of phorbolesters in food has significant effect on its acceptance. Jatropha meal obtained from treatment 3 had a crude protein (CP) content of 68%, far higher than the CP content of most oilseed meals (soyabean). This treatment seems a better method of detoxifying Jatropha curcas meal for livestock but in economic terms it is expensive to produce a meal from it.","PeriodicalId":148381,"journal":{"name":"The South Pacific Journal of Natural and Applied Sciences","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114805437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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