Road construction in Africa is faced with a shortage of quality materials, leading to delays and increased costs. Traditional materials, such as clay soils of the bar soil type, have inadequate properties for pavement...Road construction in Africa is faced with a shortage of quality materials, leading to delays and increased costs. Traditional materials, such as clay soils of the bar soil type, have inadequate properties for pavement sub-base layers, particularly in terms of bearing capacity. This study explores a composite material combining bar soil and bamboo fibers to improve the mechanical performance of bar soil, offering a sustainable and cost-effective solution. The Tori-Bossito bar soil was characterised by particle size analysis, Atterberg limits, Proctor compaction tests and the California Bearing Ratio (CBR). The results show that this material is a class A2 sandy-clay soil with a CBR of 18, which is insufficient for foundation layers requiring a CBR of over 30. To improve its performance, Sèmè-Kpodji bamboo fibers, 30 to 100 microns in diameter and 3 to 5 cm long, were incorporated at rates of 0.9% to 2.7%. The optimum mix, with 2.4% fiber, has a CBR of 35, a dry density of 1.92 t/m3 and a moisture content of 12.4%. This reinforced material is suitable as a base course for low-traffic roadways.展开更多
The fact that Morocco is an agricultural country and the large volume of biodegradable waste produced by the population make composting so important.The degradation of organic matter is facilitated by faunal and flora...The fact that Morocco is an agricultural country and the large volume of biodegradable waste produced by the population make composting so important.The degradation of organic matter is facilitated by faunal and floral macro and micro-organisms that act in different stages of maturation;studies on this fauna are quite rare both nationally and internationally.On a sample of two tons of household waste,we documented invertebrates that colonized compost heaps and then assessed the changes in the structure of the invertebrate population during the different phases.Our study revealed the presence of several zoological groups colonizing the compost heaps during the different composting phases;we noted the presence of:(1)Macroscopic invertebrates,in order of number of individuals:insect larvae,ants,earthworms,sowbugs,spiders,springtails,and millipedes,and(2)Microscopic invertebrates,the most abundant in terms of individuals:mites and nematodes.As for the order of appearance,we observed that insect larvae were the first to colonize the compost heap from the very first days of installation,followed by woodlice observed during the thermophilic phase and disappearing towards the end of the process.Earthworms were observed during the end of the thermophilic phase,while springtails were observed more during the cooling and maturation phases.Our study revealed the presence of a good quality of fauna during the composting process,which are indicators of good compost quality and play a major role in the circulation of nutrients,thus ensuring the provision of essential elements for plant nutrition.展开更多
To identify environmental risk factors associated with the development of Crohn’s disease (CD) in order to re-assess the hygiene hypothesis. METHODSA hospital-based, case-control study was carried out with CD patient...To identify environmental risk factors associated with the development of Crohn’s disease (CD) in order to re-assess the hygiene hypothesis. METHODSA hospital-based, case-control study was carried out with CD patients (n = 145) and controls (n = 163) representing a socioeconomically diverse statewide catchment area in Brazil. Controls were recruited from caregivers of patients seen in different outpatient clinics at the same hospital. A multi-item survey with 94 questions regarding family history of CD, perinatal and childhood circumstances, living conditions, tobacco use and familial socioeconomic status was carried out by interviewers. RESULTSOn the univariate analysis, predictive variables for CD included being male, under age of 40, a high education level, urban dweller, smaller family size, exposure to enteric pathogens and user of treated water (P < 0.005). On the multivariate analysis, variables significantly associated with CD were male gender (OR = 2.09), under age 40 (OR = 3.10), white (OR = 2.32), from a small family in childhood (OR = 2.34) and adulthood (OR = 3.02), absence of viral infections in childhood (OR = 2.23), exposure to enteric pathogens (OR = 2.41), having had an appendectomy (OR = 2.47) and prior or current smoker (OR = 2.83/1.12). CONCLUSIONMost variables supporting the “hygiene hypothesis” are associated with the development of CD but are not independent predictors of the diagnosis.展开更多
BACKGROUND The etiology of inflammatory bowel disease(IBD)is unknown,but it is believed to be multifactorial.The hygiene hypothesis proposes that better hygiene conditions would lead to less infectious disease during ...BACKGROUND The etiology of inflammatory bowel disease(IBD)is unknown,but it is believed to be multifactorial.The hygiene hypothesis proposes that better hygiene conditions would lead to less infectious disease during childhood and favor the development of immune-mediated diseases.AIM To test the hygiene hypothesis in IBD by assessing the environmental risk factors associated with IBD development in different regions of Brazil with diverse socioeconomic development indices.METHODS A multicenter case-control study was carried out with 548 Crohn’s disease(CD)and 492 ulcerative colitis(UC)outpatients and 416 healthy controls,from six IBD centers within different Brazilian states at diverse socioeconomic development stages.A semi-structured questionnaire with 87 socioeconomic and environmental questions was applied.Logistic regression model was created to assess the odds ratio(OR)with P value and 95%confidence intervals(CI).RESULTS Predictive variables for both diseases(CD and UC)were women[odd ratios(OR)=1.31;OR=1.69],low monthly family income(OR=1.78;OR=1.57),lower number of cohabitants(OR=1.70;OR=1.60),absence of vaccination(OR=3.11;OR=2.51),previous history of bowel infections(OR=1.78;OR=1.49),and family history of IBD(OR=5.26;OR=3.33).Associated risk factors for CD were age(18-39 years)(OR=1.73),higher educational level(OR=2.22),absence of infectious childhood diseases(OR=1.99).The UC predictive variables were living in an urban area(OR=1.62),inadequate living conditions(OR=1.48)and former smokers(OR=3.36).Appendectomy was a risk factor for CD(OR=1.58)with inverse association with UC(OR=4.79).Consumption of treated and untreated water was associated with risk of CD(OR=1.38)and UC(OR=1.53),respectively.CONCLUSION This is the first examining environmental exposures as risk factors for inflammatory bowel disease in Brazil.Most of the variables associated with disease risk support the role of the hygiene hypothesis in IBD development.展开更多
This work focuses on the design of a new type of eco-material based on Typha“Domingensis”and clay from the south of the Republic of Benin through various dosages.Three particle size classes of typha shavings were se...This work focuses on the design of a new type of eco-material based on Typha“Domingensis”and clay from the south of the Republic of Benin through various dosages.Three particle size classes of typha shavings were selected to be mixed with two types of clayin order to make parallelepiped shaped samples ready for experimentation.The massive use of these briquettes thus obtained,in the construction of habitats,would not only contribute to reducing the energy consumption inside the dwellings but also would limit the invasion of the waterways of Benin,which would facilitate navigation,fishing and river sanitation activities.In addition,this biosourced,low-polluting material would contribute to improving the energy transition by integrating it into rehabilitation of buildings.展开更多
文摘Road construction in Africa is faced with a shortage of quality materials, leading to delays and increased costs. Traditional materials, such as clay soils of the bar soil type, have inadequate properties for pavement sub-base layers, particularly in terms of bearing capacity. This study explores a composite material combining bar soil and bamboo fibers to improve the mechanical performance of bar soil, offering a sustainable and cost-effective solution. The Tori-Bossito bar soil was characterised by particle size analysis, Atterberg limits, Proctor compaction tests and the California Bearing Ratio (CBR). The results show that this material is a class A2 sandy-clay soil with a CBR of 18, which is insufficient for foundation layers requiring a CBR of over 30. To improve its performance, Sèmè-Kpodji bamboo fibers, 30 to 100 microns in diameter and 3 to 5 cm long, were incorporated at rates of 0.9% to 2.7%. The optimum mix, with 2.4% fiber, has a CBR of 35, a dry density of 1.92 t/m3 and a moisture content of 12.4%. This reinforced material is suitable as a base course for low-traffic roadways.
文摘The fact that Morocco is an agricultural country and the large volume of biodegradable waste produced by the population make composting so important.The degradation of organic matter is facilitated by faunal and floral macro and micro-organisms that act in different stages of maturation;studies on this fauna are quite rare both nationally and internationally.On a sample of two tons of household waste,we documented invertebrates that colonized compost heaps and then assessed the changes in the structure of the invertebrate population during the different phases.Our study revealed the presence of several zoological groups colonizing the compost heaps during the different composting phases;we noted the presence of:(1)Macroscopic invertebrates,in order of number of individuals:insect larvae,ants,earthworms,sowbugs,spiders,springtails,and millipedes,and(2)Microscopic invertebrates,the most abundant in terms of individuals:mites and nematodes.As for the order of appearance,we observed that insect larvae were the first to colonize the compost heap from the very first days of installation,followed by woodlice observed during the thermophilic phase and disappearing towards the end of the process.Earthworms were observed during the end of the thermophilic phase,while springtails were observed more during the cooling and maturation phases.Our study revealed the presence of a good quality of fauna during the composting process,which are indicators of good compost quality and play a major role in the circulation of nutrients,thus ensuring the provision of essential elements for plant nutrition.
文摘To identify environmental risk factors associated with the development of Crohn’s disease (CD) in order to re-assess the hygiene hypothesis. METHODSA hospital-based, case-control study was carried out with CD patients (n = 145) and controls (n = 163) representing a socioeconomically diverse statewide catchment area in Brazil. Controls were recruited from caregivers of patients seen in different outpatient clinics at the same hospital. A multi-item survey with 94 questions regarding family history of CD, perinatal and childhood circumstances, living conditions, tobacco use and familial socioeconomic status was carried out by interviewers. RESULTSOn the univariate analysis, predictive variables for CD included being male, under age of 40, a high education level, urban dweller, smaller family size, exposure to enteric pathogens and user of treated water (P < 0.005). On the multivariate analysis, variables significantly associated with CD were male gender (OR = 2.09), under age 40 (OR = 3.10), white (OR = 2.32), from a small family in childhood (OR = 2.34) and adulthood (OR = 3.02), absence of viral infections in childhood (OR = 2.23), exposure to enteric pathogens (OR = 2.41), having had an appendectomy (OR = 2.47) and prior or current smoker (OR = 2.83/1.12). CONCLUSIONMost variables supporting the “hygiene hypothesis” are associated with the development of CD but are not independent predictors of the diagnosis.
基金Supported by Carlos Chagas Filho Rio de Janeiro State Research Foundation(Faperj),No.100.044/2011.
文摘BACKGROUND The etiology of inflammatory bowel disease(IBD)is unknown,but it is believed to be multifactorial.The hygiene hypothesis proposes that better hygiene conditions would lead to less infectious disease during childhood and favor the development of immune-mediated diseases.AIM To test the hygiene hypothesis in IBD by assessing the environmental risk factors associated with IBD development in different regions of Brazil with diverse socioeconomic development indices.METHODS A multicenter case-control study was carried out with 548 Crohn’s disease(CD)and 492 ulcerative colitis(UC)outpatients and 416 healthy controls,from six IBD centers within different Brazilian states at diverse socioeconomic development stages.A semi-structured questionnaire with 87 socioeconomic and environmental questions was applied.Logistic regression model was created to assess the odds ratio(OR)with P value and 95%confidence intervals(CI).RESULTS Predictive variables for both diseases(CD and UC)were women[odd ratios(OR)=1.31;OR=1.69],low monthly family income(OR=1.78;OR=1.57),lower number of cohabitants(OR=1.70;OR=1.60),absence of vaccination(OR=3.11;OR=2.51),previous history of bowel infections(OR=1.78;OR=1.49),and family history of IBD(OR=5.26;OR=3.33).Associated risk factors for CD were age(18-39 years)(OR=1.73),higher educational level(OR=2.22),absence of infectious childhood diseases(OR=1.99).The UC predictive variables were living in an urban area(OR=1.62),inadequate living conditions(OR=1.48)and former smokers(OR=3.36).Appendectomy was a risk factor for CD(OR=1.58)with inverse association with UC(OR=4.79).Consumption of treated and untreated water was associated with risk of CD(OR=1.38)and UC(OR=1.53),respectively.CONCLUSION This is the first examining environmental exposures as risk factors for inflammatory bowel disease in Brazil.Most of the variables associated with disease risk support the role of the hygiene hypothesis in IBD development.
文摘This work focuses on the design of a new type of eco-material based on Typha“Domingensis”and clay from the south of the Republic of Benin through various dosages.Three particle size classes of typha shavings were selected to be mixed with two types of clayin order to make parallelepiped shaped samples ready for experimentation.The massive use of these briquettes thus obtained,in the construction of habitats,would not only contribute to reducing the energy consumption inside the dwellings but also would limit the invasion of the waterways of Benin,which would facilitate navigation,fishing and river sanitation activities.In addition,this biosourced,low-polluting material would contribute to improving the energy transition by integrating it into rehabilitation of buildings.
