Environmental endocrine disrupting chemicals (EDCs), commonly found in the environment, come from industry and agriculture, including pesticides, fungicides, insecticides, herbicides, and other chemicals. Nowadays, ...Environmental endocrine disrupting chemicals (EDCs), commonly found in the environment, come from industry and agriculture, including pesticides, fungicides, insecticides, herbicides, and other chemicals. Nowadays, more and more EDCs were released into the environment. EDCs go into water body via atmosphere sedi-mentation, surface runoff, soil eluviation, etc., so water body becomes the main place for existing. In order to attract scientific and public attention worldwide and to prevent EDCs pol ution, in this study we reviewed the classification of EDCs and their concentrations in natural water bodies, drinking water sources and water plants, and the reproductive toxicity of EDCs to fish were reviewed. EDCs could disturb the endocrine system and make reproductive organs and reproduction abnor-mal, resulting in fertility descending, reproduction function damage, community quan-tity decrease and even species extinction. In addition, EDCs could disrupt the homeostasis maintained by hormones, which would result in defects of neural de-velopment and abnormalities of the endocrine and reproductive systems. The exact molecular mechanisms have not been completely reported, but researches have suggested that multiple mechanisms were involved in the action of EDCs. Although there have been researches on the biohazard of EDCs, there stil exist problems of weakness in fundamental researches, difficulties in recognizing and identifying EDCs and high cost, which restraint the knowledge on them.展开更多
The object of is to evaluate assimilable organic carbon(AOC) degradation rate by intensified biological technique in advanced water treatment. By artificially acclimating and cultivating strains attached onto carbon...The object of is to evaluate assimilable organic carbon(AOC) degradation rate by intensified biological technique in advanced water treatment. By artificially acclimating and cultivating strains attached onto carbon surface, the selected strains can be intensified for their degradation to organic matters. The research indicates that ozonation process increases AOC concentration considerably, however, it is beneficial to microdegradation. Temperature and empty bed contact time ( TEBC ) are two important factors affecting microbiology. From 14 to 27 ℃, intensified biological carbon can remove AOC better compared with granular activated carbon (GAC). Under identical TERC, intensified technique increases more than 10% AOC reduction.展开更多
This study was conducted to evaluate the distribution characteristics of phosphorus and its species in 14 sediments samples collected from Lake Hongfeng based on sequential extraction. Lake Hongfeng, a major drinking-...This study was conducted to evaluate the distribution characteristics of phosphorus and its species in 14 sediments samples collected from Lake Hongfeng based on sequential extraction. Lake Hongfeng, a major drinking-water source for Guiyang City in southwestern China, is one of the largest artificial reservoirs located in a typical karstic area of the Yunnan-Guizhou Plateau. The results of this study indicate that the average percentages of DP, Al-P, Fe-P, Ca-P and OP in the lake sediments were 0.52, 6.59, 6.09, 42.85 and 40.27, respectively. The concentrations of organic phosphorus (OP) were lower than those of inorganic phosphorus (IP), which consisted mainly of calcium-bound phosphorus (Ca-P). The high concentrations of Ca-P may temporarily control the release of phosphorus from the sediments because it is a relatively stable, inert, and non-bioavailable phosphorus fraction. However, a large number of phosphate solubilizing bacteria can transform insoluble phosphate into bioavailable forms. Moreover, the concentrations of total phosphorus (TP) in the lake sediments were high; thus, the potential for the release of phosphorus from the sediments to the water column and phosphorus bioavailability were still significant. Further statistical analyses of the results revealed significant correlations between phosphorus species in sediments from the lake with two extractable principal component species (PCs) and five selectable cluster levels allowing interpretation of possible origins of phosphorus loading and the release of phosphorus. Furthermore, available remediation measures were briefly assessed for the lake with consideration of its distinctive environmental features.展开更多
The potability of water wells, drilling and tap water is the determining factor for the quality management of health of the urban and rural population. This study has been done on the basis of monitoring aspect such a...The potability of water wells, drilling and tap water is the determining factor for the quality management of health of the urban and rural population. This study has been done on the basis of monitoring aspect such as pH, content ammonium, nitrate, nitrite and chloride from a physico chemical point of view. This study allowed the chemical and bacteriological analysis of samples, based on the result obtained, and the potability of water was defined. The bacteriological analysis was carried out taking account of the total flora, coliforms and Escherichia coll. This work gave rise to analyze 36 samples of water from wells, eight samples of drilling water and nine samples of water taps from municipalities such as Mamou, Dalaba and Pita. Water wells represent 90% of water supplies in drinking water to the population. In this research, collection of samples was very important. This study shows that 16 samples from 52 are potable, therefore, it is urgent to focus on the treatment of sewage in order to ensure better health for the population from administrative region of Mamou.展开更多
Despite the endemic drought, arid climate and associated limited freshwater resources, as well as difficult geopolitical realities, Israel can provide a reliable supply of high quality water to a rapidly growing popul...Despite the endemic drought, arid climate and associated limited freshwater resources, as well as difficult geopolitical realities, Israel can provide a reliable supply of high quality water to a rapidly growing population. The achievements of water supply in Israel can be summarized as water technologies (like water transportation and purification, desalination, wastewater treatment, effluent reuse, storm water catchment, control systems, rain enhancement and drip irrigation, etc.), water management and legislation as well as water industry. In view of the national concern regarding the quality and quantity of the water, the skills, technologies and know-how that Israel has accumulated in water supply and irrigation can give us enlightenment that is also presented in this paper.展开更多
Starting from the fact that water is quite arguably the source of life, the authors agreed to set up a project on water and name it: "REFLECTION". Particular focus was placed on the following issues: water in natu...Starting from the fact that water is quite arguably the source of life, the authors agreed to set up a project on water and name it: "REFLECTION". Particular focus was placed on the following issues: water in nature, importance of water in human life, physical and chemical properties of water, protection of water in nature. The aim of the project was to make students aware of the importance of water for health as well as to help them develop a rational relationship towards drinking water. In order to find answers to the issues raised, the authors designed worksheets, PowerPoint presentations, educational games (ecological postcards, dominoes, memory games, etc.). The authors even tried our hand at making a comic strip. Students learned about the influence of water on health, as well as about water content in particular foods. The long-term goal of the project is to introduce children to scientific approach and methodology. Through active participation and dialogue, students discover cooperative learning and acquire skills that will be beneficial to them as well as to the wider community. Working on the project, students' evidence that the role of an individual is a key one in building a better world. This insight helps develop their civic skills and attitudes that serve as the starting point for environmental education. The authors made numerous adaptations and implemented individual approach with the goal of training students for independent work and life according to their personal abilities in line with the principles of inclusive education. Students conduct experiments following step-by-step instructions on specially adapted worksheets. Each student gets positive feedback and experiences the joy of success that leads to the development of self-confidence and love of work and learning.展开更多
This study examined the impact of farmers' health on labor data was collected through a field survey of 290 rural households productivity of female farmers in Imo State, Nigeria. Primary Descriptive statistics and es...This study examined the impact of farmers' health on labor data was collected through a field survey of 290 rural households productivity of female farmers in Imo State, Nigeria. Primary Descriptive statistics and estimation of efficiency following maximum likelihood estimation (MLE) procedure available in Frontier 4.1 were used to analyze the data. Results from the analyses showed that malaria has the highest prevalence level among female farmers in the study area followed by typhoid fever. The causes of sicknesses vary from cold, stress, mosquito bites and bad drinking water. Furthermore, the results showed that sicknesses affect the productivity of farmers by reducing their work capacity. Also, the distance to source of drinking water from home, source of drinking water, age, body mass index of farmers are also found to significantly affect the physical work output of farmers in the study area. The result shows that the distribution of farmers was highly skewed with about 99% of the farmers having their efficiency above 0.61. This indicates that majority of the farmers are technically efficient in the allocation of resources to crop production, The result also shows that the average efficiency was about 82.9%. Thus, the farmers' level of efficiency can be improved if there is a shift in the fi'ontier, i.e. if factors contributing to inefficiency are adequately controlled. The study recommends the need to invest more on human capital especially health for there to be an improvement in rural productivity. Also, rural development policies should include health policies especially for women since it has a great influence on the household and emphasis should also be on preventive rather than curative health services.展开更多
Two experiments were conducted to determine the effects of L y s ine(Lys) and Net Energy (NE) levels on growth performance (Exp. I) and N balance (Exp. 2) in growing pig. In Exp. 1, 36 castrated pigs [21.35 -4...Two experiments were conducted to determine the effects of L y s ine(Lys) and Net Energy (NE) levels on growth performance (Exp. I) and N balance (Exp. 2) in growing pig. In Exp. 1, 36 castrated pigs [21.35 -4- 0.55 kg of body weight (BW)] were allotted to six treatments with six replicates per treatment. Pigs were fed two levels of Lys (low and high) and three levels of NE (low, med, or high) in a 2×3 factorial arrangement. The experiment lasted for 35 d. There were no effects of dietary Lys and NE on pig performance (P〉0.05, but a Lys×NE interaction in ADG was observed (P〈0.05). In Exp. 2, 24 pigs were used to determine the effects of diet in Exp. 1 on pig N balance. Neither Lys nor NE level affected N retention (g/d) (P〉0.0). Lys×NE interaction in N retention (g/d) (P〈0.01) and in N apparent biological value (ABV) (P〈0.05) was observed. Pigs fed the low Lys diet had lower serum urea nitrogen (SUN) concentrations compared with the high Lys treatment (P〈0.01). Pigs fed the med-NE diet had lower SUN concentrations compared with the pigs fed the low-NE diet (P〈0.1). These results suggest that pigs from 21 kg to 50 kg BW fed diets containing 0.83% standardized ileal digestible Lysine and 2351 Kcal of NE/kg had maximum ADG and N retention.展开更多
The physico-chemical and biological (algal and bacterial) quality of tap water in Tanta City were elucidated. Samples were collected during December 2011, covering all the water plants and the areal extension of the...The physico-chemical and biological (algal and bacterial) quality of tap water in Tanta City were elucidated. Samples were collected during December 2011, covering all the water plants and the areal extension of the pipe line network in Tanta. Total dissolved solids content classifies water origin into surface water, shallow and deep groundwater. Fe, Mn and hardness in some samples of groundwater origin are obviously exceeding the WHO (World Health Organization) limit. Mostly, green algae are found (31 species), followed by diatoms (19 species), then blue-green algae (13 species). CCA (Canonical Corresponding Analysis) indicates that green algae are strongly correlated with pH, NH4, alkalinity, Mn and Si; diatoms with EC (electric conductivity), turbidity, Zn and Si and blue green algae with EC and alkalinity. 50% of samples of surface origin, 80% of samples of both deep and shallow groundwater origins crossed WHO and Egyptian guideline in their content of mean TCC (Total Coliform Count). CCA estimates strong correlations of TCC with temperature, NH4 and PO4; E. coli with EC; heterotrophic bacteria with turbidity and NO3; Salmonella sp. with Si and SO4 and Pseudomonas aeruginosa with Mn. Finally, the water plants treatment may be not effective and pipes serve as a reservoir for pathogenic microorganisms.展开更多
Arsenic (As) is one of the most important elemental pollutants in groundwater and drinking water because it causes health problem of arsenicosis after consumption of drinking arsenic-rich water more than 5-10 years....Arsenic (As) is one of the most important elemental pollutants in groundwater and drinking water because it causes health problem of arsenicosis after consumption of drinking arsenic-rich water more than 5-10 years. Arsenic contamination of groundwater is an emerging issue in Mekong Basin including Cambodia, Vietnam, and Thailand. In Thailand, information about arsenic contamination in drinking water resources are quite rare due to that arsenic is not the main element in water qualification assay. The objective of this study is to determine groundwater quality and arsenic contamination in rural Mekong Basin, Ubon Ratchathani. Groundwater samples were collected from 20 different sampling points, between August 2009 and February 2010 in Amphoe Khemmarat, Ubon Ratchathani, Thailand. Physical and chemical characteristics of groundwater were determined. It was observed that the groundwater was 27.9-30.3 ~C, pH 5.7-6.9. The conductivity was 707-767 p.S.cm". Dissolved oxygen was 2.04-5.12 mg.L-1 and TDS was 352-384 mg.L~. The samples showed soft- to very hardness-water properties. In some area, few parameters like CI, Fe, Mn, and As exceeded the WHO guideline limits. This result represents basic information for quality of groundwater and the arsenic contamination in rural Mekong Basin, Ubon Ratchathani. Thus, it is probably useful for arsenic standard level assignment and public health authorities. Moreover, it also leads to establish research activity in treatment of arsenic-contaminated groundwater for different purposes展开更多
Despite the intention of minimum wage policy to maintain the living standards of low-income groups in the formal sector, this paper has found that the actual result of this policy produces the "big push" impact on C...Despite the intention of minimum wage policy to maintain the living standards of low-income groups in the formal sector, this paper has found that the actual result of this policy produces the "big push" impact on China's economy under certain conditions, i.e. it is conducive to achieving the equilibrium of high wage, high consumption and formalization. The result shows that the elasticity of income growth from raising the minimum wage standard is greater for formal sector employees than for informal sector employees and is characterized by a U-shaped pattern in terms of quantiles. Thus, minimum wage hikes have widened wage gaps between and within sectors. Rising minimum wage standards greatly stimulate consumption with each 10% increase expected to bring about an additional urban household consumption of about 1.167 billion yuan in the surveyed four provinces. With local minimum wage hikes, the formal sector of wholesale and retail, hotel and catering services expands and the informal sector contracts, while the real estate sector experiences a "reverse formalization" trend. Based on the "big push theory", this paper concludes that against the backdrop of extensive, frequent and substantial minimum wage hikes, demand and sector TFP growth are the major causes of sector heterogeneity.展开更多
Xylopia aethiopica dried fruits (gains of selim) as an additive in starter broilers production was investigated. For this purpose, a total of 195-day old broiler chicks (Arbor acres) were randomly allocated into f...Xylopia aethiopica dried fruits (gains of selim) as an additive in starter broilers production was investigated. For this purpose, a total of 195-day old broiler chicks (Arbor acres) were randomly allocated into five treatments groups with 39 chicks and three replicates of 13 chicks in each. Blended grains of selim was given through drinking water on treatments T2, T3, T4 and T5 at concentrations of 0.4, 0.6, 0.8 and 1,0 g/L, while chicks on treatment T1 (control) received antibiotics (Doxy-gen 20/20 WSP: Doxycycline hyclate 200 mg and Gentamicine sulfate 200 mg) at 0.3 g/L of water. All the experimental chicks were fed ad libitum with diet containing 23% crude protein and 2,851.55 kcal/kg metabolizable energy for 28 d. The results revealed that there were similarities (P 〉 0.05) in final body weight, total weight gain, daily weight gain, total feed intake, daily feed intake and feed conversion ratio among the treatments. There were significant (P 〈 0.05) differences in the microbial count of faeces before the birds received antibiotics and grains of selim, but count were similar (P 〉 0.05) after grains of selim and antibiotics were administered. Cost of total feed consumed, cost of per kg feed and cost of per kg weight were significantly (P 〈 0.05) higher in treatment T1, but cost differential and relative cost benefit were similar (P 〉 0.05). Results indicate that grains of selim have antimicrobial and anthelminthic properties, and promote growth in broiler chickens.展开更多
It is important to obtain a considerable quantity of DNA from oligotrophic environments such as a drinking water distribution system(DWDS)to study microbial communities by molecular biotechnology,and DNA yield is alwa...It is important to obtain a considerable quantity of DNA from oligotrophic environments such as a drinking water distribution system(DWDS)to study microbial communities by molecular biotechnology,and DNA yield is always one of the biggest problems when performing metagenomic sequencing on drinking water samples.To obtain as many microbes as possible,ultrasound has been widely used in cell detachment,but studies on the optimal ultrasonic parameters for biofilm in DWDS have rarely been seen.The effects of three ultrasonic parameters,including power,duration,and the number of ultrasound treatments(USTs)on the selected monoculture bacteria(Pelomonas sp.)biofilm were studied first.Then the optimal values of each ultrasonic parameter were initially determined.Based on these values,three levels of each ultrasonic parameter were selected,and then an orthogonal experiment was conducted to further study drinking water biofilm,and finally the optimal ultrasonic parameters for the effective separation of biofilm cells in DWDS were determined.The results showed that the optimal ultrasonic power,duration,and the number of USTs are 13 W,1 min,and 15,respectively.A 20-min interval is needed between two USTs.The present optimal UST,which does not lose DNA quality,can increase the amount of extractable DNA by at least 4.78 times compared to samples without UST.This study provides a pretreatment methodology for extracting more and reliable DNA from biofilm in DWDS,and can better solve the problem of DNA collection in oligotrophic environments.展开更多
A technique for producing driping water from air using adsorbents driven by solar energy is Presented,its principle is described, and its applicability is experimentally verified.
The efficiency of chlorine and chloramines disinfection on biofilm development in a simulated drinking water distribution system was investigated by using heterotrophic bacterial spread plate technique. The experiment...The efficiency of chlorine and chloramines disinfection on biofilm development in a simulated drinking water distribution system was investigated by using heterotrophic bacterial spread plate technique. The experiments were carried out with four annular reactors (ARs) with stainless steel (SS) or copper (Cu) material slides. The results showed that there were fewer bacteria attached to Cu slides without a disinfectant compared with those attached to SS slides. When the water was disinfected with chloramines, the heterotrophic plate counts (HPCs) on the biofilm attached to the Cu slides were significantly lower (by 3.46 log CFU/cm2) than those attached to the SS slides. Likewise, the biofilm HPC numbers on the Cu slides were slightly lower (by 1.19 log CFU/cm2) than those on the SS slides disinfected with chlorine. In a quasi-steady state, the HPC levels on Cu slides can be reduced to 3.0 log CFU/cm2 with chlorine and to about 0.9 log CFU/cm2 with chloramines. The addition of chloramines resulted in a more efficient reduction of biofilm heterotrophic bacteria than did chlorine. We concluded that the chlorine and chloramines levels usually employed in water distribution system were not sufficient to prevent the growth and development of microbial biofilm. The combination of copper pipe slides and chloramines as the disinfectant was the most efficient combination to bring about diminished bacterial levels.展开更多
基金Supported by the China Agriculture Research System(CARS49)~~
文摘Environmental endocrine disrupting chemicals (EDCs), commonly found in the environment, come from industry and agriculture, including pesticides, fungicides, insecticides, herbicides, and other chemicals. Nowadays, more and more EDCs were released into the environment. EDCs go into water body via atmosphere sedi-mentation, surface runoff, soil eluviation, etc., so water body becomes the main place for existing. In order to attract scientific and public attention worldwide and to prevent EDCs pol ution, in this study we reviewed the classification of EDCs and their concentrations in natural water bodies, drinking water sources and water plants, and the reproductive toxicity of EDCs to fish were reviewed. EDCs could disturb the endocrine system and make reproductive organs and reproduction abnor-mal, resulting in fertility descending, reproduction function damage, community quan-tity decrease and even species extinction. In addition, EDCs could disrupt the homeostasis maintained by hormones, which would result in defects of neural de-velopment and abnormalities of the endocrine and reproductive systems. The exact molecular mechanisms have not been completely reported, but researches have suggested that multiple mechanisms were involved in the action of EDCs. Although there have been researches on the biohazard of EDCs, there stil exist problems of weakness in fundamental researches, difficulties in recognizing and identifying EDCs and high cost, which restraint the knowledge on them.
基金Sponsored by China Postdoctoral Science Foundation (Grant No.20060400178) and Shanghai Postdoctoral Scientific Program(Grant No.06R214204).
文摘The object of is to evaluate assimilable organic carbon(AOC) degradation rate by intensified biological technique in advanced water treatment. By artificially acclimating and cultivating strains attached onto carbon surface, the selected strains can be intensified for their degradation to organic matters. The research indicates that ozonation process increases AOC concentration considerably, however, it is beneficial to microdegradation. Temperature and empty bed contact time ( TEBC ) are two important factors affecting microbiology. From 14 to 27 ℃, intensified biological carbon can remove AOC better compared with granular activated carbon (GAC). Under identical TERC, intensified technique increases more than 10% AOC reduction.
基金Supported by the National Natural Science Foundation of China (No.20967003)
文摘This study was conducted to evaluate the distribution characteristics of phosphorus and its species in 14 sediments samples collected from Lake Hongfeng based on sequential extraction. Lake Hongfeng, a major drinking-water source for Guiyang City in southwestern China, is one of the largest artificial reservoirs located in a typical karstic area of the Yunnan-Guizhou Plateau. The results of this study indicate that the average percentages of DP, Al-P, Fe-P, Ca-P and OP in the lake sediments were 0.52, 6.59, 6.09, 42.85 and 40.27, respectively. The concentrations of organic phosphorus (OP) were lower than those of inorganic phosphorus (IP), which consisted mainly of calcium-bound phosphorus (Ca-P). The high concentrations of Ca-P may temporarily control the release of phosphorus from the sediments because it is a relatively stable, inert, and non-bioavailable phosphorus fraction. However, a large number of phosphate solubilizing bacteria can transform insoluble phosphate into bioavailable forms. Moreover, the concentrations of total phosphorus (TP) in the lake sediments were high; thus, the potential for the release of phosphorus from the sediments to the water column and phosphorus bioavailability were still significant. Further statistical analyses of the results revealed significant correlations between phosphorus species in sediments from the lake with two extractable principal component species (PCs) and five selectable cluster levels allowing interpretation of possible origins of phosphorus loading and the release of phosphorus. Furthermore, available remediation measures were briefly assessed for the lake with consideration of its distinctive environmental features.
文摘The potability of water wells, drilling and tap water is the determining factor for the quality management of health of the urban and rural population. This study has been done on the basis of monitoring aspect such as pH, content ammonium, nitrate, nitrite and chloride from a physico chemical point of view. This study allowed the chemical and bacteriological analysis of samples, based on the result obtained, and the potability of water was defined. The bacteriological analysis was carried out taking account of the total flora, coliforms and Escherichia coll. This work gave rise to analyze 36 samples of water from wells, eight samples of drilling water and nine samples of water taps from municipalities such as Mamou, Dalaba and Pita. Water wells represent 90% of water supplies in drinking water to the population. In this research, collection of samples was very important. This study shows that 16 samples from 52 are potable, therefore, it is urgent to focus on the treatment of sewage in order to ensure better health for the population from administrative region of Mamou.
基金sponsored by China Scholarship Council (Grant No. LJC [2007]3020)Scholarship Fund granted by the Board of Directors of Igud Yotzei Sin in Israel and Israel-China Friendship Society
文摘Despite the endemic drought, arid climate and associated limited freshwater resources, as well as difficult geopolitical realities, Israel can provide a reliable supply of high quality water to a rapidly growing population. The achievements of water supply in Israel can be summarized as water technologies (like water transportation and purification, desalination, wastewater treatment, effluent reuse, storm water catchment, control systems, rain enhancement and drip irrigation, etc.), water management and legislation as well as water industry. In view of the national concern regarding the quality and quantity of the water, the skills, technologies and know-how that Israel has accumulated in water supply and irrigation can give us enlightenment that is also presented in this paper.
文摘Starting from the fact that water is quite arguably the source of life, the authors agreed to set up a project on water and name it: "REFLECTION". Particular focus was placed on the following issues: water in nature, importance of water in human life, physical and chemical properties of water, protection of water in nature. The aim of the project was to make students aware of the importance of water for health as well as to help them develop a rational relationship towards drinking water. In order to find answers to the issues raised, the authors designed worksheets, PowerPoint presentations, educational games (ecological postcards, dominoes, memory games, etc.). The authors even tried our hand at making a comic strip. Students learned about the influence of water on health, as well as about water content in particular foods. The long-term goal of the project is to introduce children to scientific approach and methodology. Through active participation and dialogue, students discover cooperative learning and acquire skills that will be beneficial to them as well as to the wider community. Working on the project, students' evidence that the role of an individual is a key one in building a better world. This insight helps develop their civic skills and attitudes that serve as the starting point for environmental education. The authors made numerous adaptations and implemented individual approach with the goal of training students for independent work and life according to their personal abilities in line with the principles of inclusive education. Students conduct experiments following step-by-step instructions on specially adapted worksheets. Each student gets positive feedback and experiences the joy of success that leads to the development of self-confidence and love of work and learning.
文摘This study examined the impact of farmers' health on labor data was collected through a field survey of 290 rural households productivity of female farmers in Imo State, Nigeria. Primary Descriptive statistics and estimation of efficiency following maximum likelihood estimation (MLE) procedure available in Frontier 4.1 were used to analyze the data. Results from the analyses showed that malaria has the highest prevalence level among female farmers in the study area followed by typhoid fever. The causes of sicknesses vary from cold, stress, mosquito bites and bad drinking water. Furthermore, the results showed that sicknesses affect the productivity of farmers by reducing their work capacity. Also, the distance to source of drinking water from home, source of drinking water, age, body mass index of farmers are also found to significantly affect the physical work output of farmers in the study area. The result shows that the distribution of farmers was highly skewed with about 99% of the farmers having their efficiency above 0.61. This indicates that majority of the farmers are technically efficient in the allocation of resources to crop production, The result also shows that the average efficiency was about 82.9%. Thus, the farmers' level of efficiency can be improved if there is a shift in the fi'ontier, i.e. if factors contributing to inefficiency are adequately controlled. The study recommends the need to invest more on human capital especially health for there to be an improvement in rural productivity. Also, rural development policies should include health policies especially for women since it has a great influence on the household and emphasis should also be on preventive rather than curative health services.
文摘Two experiments were conducted to determine the effects of L y s ine(Lys) and Net Energy (NE) levels on growth performance (Exp. I) and N balance (Exp. 2) in growing pig. In Exp. 1, 36 castrated pigs [21.35 -4- 0.55 kg of body weight (BW)] were allotted to six treatments with six replicates per treatment. Pigs were fed two levels of Lys (low and high) and three levels of NE (low, med, or high) in a 2×3 factorial arrangement. The experiment lasted for 35 d. There were no effects of dietary Lys and NE on pig performance (P〉0.05, but a Lys×NE interaction in ADG was observed (P〈0.05). In Exp. 2, 24 pigs were used to determine the effects of diet in Exp. 1 on pig N balance. Neither Lys nor NE level affected N retention (g/d) (P〉0.0). Lys×NE interaction in N retention (g/d) (P〈0.01) and in N apparent biological value (ABV) (P〈0.05) was observed. Pigs fed the low Lys diet had lower serum urea nitrogen (SUN) concentrations compared with the high Lys treatment (P〈0.01). Pigs fed the med-NE diet had lower SUN concentrations compared with the pigs fed the low-NE diet (P〈0.1). These results suggest that pigs from 21 kg to 50 kg BW fed diets containing 0.83% standardized ileal digestible Lysine and 2351 Kcal of NE/kg had maximum ADG and N retention.
文摘The physico-chemical and biological (algal and bacterial) quality of tap water in Tanta City were elucidated. Samples were collected during December 2011, covering all the water plants and the areal extension of the pipe line network in Tanta. Total dissolved solids content classifies water origin into surface water, shallow and deep groundwater. Fe, Mn and hardness in some samples of groundwater origin are obviously exceeding the WHO (World Health Organization) limit. Mostly, green algae are found (31 species), followed by diatoms (19 species), then blue-green algae (13 species). CCA (Canonical Corresponding Analysis) indicates that green algae are strongly correlated with pH, NH4, alkalinity, Mn and Si; diatoms with EC (electric conductivity), turbidity, Zn and Si and blue green algae with EC and alkalinity. 50% of samples of surface origin, 80% of samples of both deep and shallow groundwater origins crossed WHO and Egyptian guideline in their content of mean TCC (Total Coliform Count). CCA estimates strong correlations of TCC with temperature, NH4 and PO4; E. coli with EC; heterotrophic bacteria with turbidity and NO3; Salmonella sp. with Si and SO4 and Pseudomonas aeruginosa with Mn. Finally, the water plants treatment may be not effective and pipes serve as a reservoir for pathogenic microorganisms.
文摘Arsenic (As) is one of the most important elemental pollutants in groundwater and drinking water because it causes health problem of arsenicosis after consumption of drinking arsenic-rich water more than 5-10 years. Arsenic contamination of groundwater is an emerging issue in Mekong Basin including Cambodia, Vietnam, and Thailand. In Thailand, information about arsenic contamination in drinking water resources are quite rare due to that arsenic is not the main element in water qualification assay. The objective of this study is to determine groundwater quality and arsenic contamination in rural Mekong Basin, Ubon Ratchathani. Groundwater samples were collected from 20 different sampling points, between August 2009 and February 2010 in Amphoe Khemmarat, Ubon Ratchathani, Thailand. Physical and chemical characteristics of groundwater were determined. It was observed that the groundwater was 27.9-30.3 ~C, pH 5.7-6.9. The conductivity was 707-767 p.S.cm". Dissolved oxygen was 2.04-5.12 mg.L-1 and TDS was 352-384 mg.L~. The samples showed soft- to very hardness-water properties. In some area, few parameters like CI, Fe, Mn, and As exceeded the WHO guideline limits. This result represents basic information for quality of groundwater and the arsenic contamination in rural Mekong Basin, Ubon Ratchathani. Thus, it is probably useful for arsenic standard level assignment and public health authorities. Moreover, it also leads to establish research activity in treatment of arsenic-contaminated groundwater for different purposes
基金Major project of National Social Sciences Foundation"Characteristics and Policy Orientation Research on the New Normal of China's Economic Growth"(Grant No.15ZDA008)Major project of National Natural Sciences Foundation"Research on the Mechanism and Policy of Promoting Industrial Upgrade in Economic Developed Regions"(Grant No.71333002)
文摘Despite the intention of minimum wage policy to maintain the living standards of low-income groups in the formal sector, this paper has found that the actual result of this policy produces the "big push" impact on China's economy under certain conditions, i.e. it is conducive to achieving the equilibrium of high wage, high consumption and formalization. The result shows that the elasticity of income growth from raising the minimum wage standard is greater for formal sector employees than for informal sector employees and is characterized by a U-shaped pattern in terms of quantiles. Thus, minimum wage hikes have widened wage gaps between and within sectors. Rising minimum wage standards greatly stimulate consumption with each 10% increase expected to bring about an additional urban household consumption of about 1.167 billion yuan in the surveyed four provinces. With local minimum wage hikes, the formal sector of wholesale and retail, hotel and catering services expands and the informal sector contracts, while the real estate sector experiences a "reverse formalization" trend. Based on the "big push theory", this paper concludes that against the backdrop of extensive, frequent and substantial minimum wage hikes, demand and sector TFP growth are the major causes of sector heterogeneity.
文摘Xylopia aethiopica dried fruits (gains of selim) as an additive in starter broilers production was investigated. For this purpose, a total of 195-day old broiler chicks (Arbor acres) were randomly allocated into five treatments groups with 39 chicks and three replicates of 13 chicks in each. Blended grains of selim was given through drinking water on treatments T2, T3, T4 and T5 at concentrations of 0.4, 0.6, 0.8 and 1,0 g/L, while chicks on treatment T1 (control) received antibiotics (Doxy-gen 20/20 WSP: Doxycycline hyclate 200 mg and Gentamicine sulfate 200 mg) at 0.3 g/L of water. All the experimental chicks were fed ad libitum with diet containing 23% crude protein and 2,851.55 kcal/kg metabolizable energy for 28 d. The results revealed that there were similarities (P 〉 0.05) in final body weight, total weight gain, daily weight gain, total feed intake, daily feed intake and feed conversion ratio among the treatments. There were significant (P 〈 0.05) differences in the microbial count of faeces before the birds received antibiotics and grains of selim, but count were similar (P 〉 0.05) after grains of selim and antibiotics were administered. Cost of total feed consumed, cost of per kg feed and cost of per kg weight were significantly (P 〈 0.05) higher in treatment T1, but cost differential and relative cost benefit were similar (P 〉 0.05). Results indicate that grains of selim have antimicrobial and anthelminthic properties, and promote growth in broiler chickens.
基金Project supported by the Major Science and Technology Program for Water Pollution Control and Treatment(No.2017ZX07201004)the National Natural Science Foundation of China(No.51678520)。
文摘It is important to obtain a considerable quantity of DNA from oligotrophic environments such as a drinking water distribution system(DWDS)to study microbial communities by molecular biotechnology,and DNA yield is always one of the biggest problems when performing metagenomic sequencing on drinking water samples.To obtain as many microbes as possible,ultrasound has been widely used in cell detachment,but studies on the optimal ultrasonic parameters for biofilm in DWDS have rarely been seen.The effects of three ultrasonic parameters,including power,duration,and the number of ultrasound treatments(USTs)on the selected monoculture bacteria(Pelomonas sp.)biofilm were studied first.Then the optimal values of each ultrasonic parameter were initially determined.Based on these values,three levels of each ultrasonic parameter were selected,and then an orthogonal experiment was conducted to further study drinking water biofilm,and finally the optimal ultrasonic parameters for the effective separation of biofilm cells in DWDS were determined.The results showed that the optimal ultrasonic power,duration,and the number of USTs are 13 W,1 min,and 15,respectively.A 20-min interval is needed between two USTs.The present optimal UST,which does not lose DNA quality,can increase the amount of extractable DNA by at least 4.78 times compared to samples without UST.This study provides a pretreatment methodology for extracting more and reliable DNA from biofilm in DWDS,and can better solve the problem of DNA collection in oligotrophic environments.
文摘A technique for producing driping water from air using adsorbents driven by solar energy is Presented,its principle is described, and its applicability is experimentally verified.
基金supported by the National Natural Science Foundation of China (No. 50878164)the National Key Technologies Supporting Program of China during the 11th Five-Year Plan Period (Nos. 2006BAJ08B02 and 2006BAJ08B06)the Program for Young Excellent Talents in Tongji University (No. 2007KJ016), China
文摘The efficiency of chlorine and chloramines disinfection on biofilm development in a simulated drinking water distribution system was investigated by using heterotrophic bacterial spread plate technique. The experiments were carried out with four annular reactors (ARs) with stainless steel (SS) or copper (Cu) material slides. The results showed that there were fewer bacteria attached to Cu slides without a disinfectant compared with those attached to SS slides. When the water was disinfected with chloramines, the heterotrophic plate counts (HPCs) on the biofilm attached to the Cu slides were significantly lower (by 3.46 log CFU/cm2) than those attached to the SS slides. Likewise, the biofilm HPC numbers on the Cu slides were slightly lower (by 1.19 log CFU/cm2) than those on the SS slides disinfected with chlorine. In a quasi-steady state, the HPC levels on Cu slides can be reduced to 3.0 log CFU/cm2 with chlorine and to about 0.9 log CFU/cm2 with chloramines. The addition of chloramines resulted in a more efficient reduction of biofilm heterotrophic bacteria than did chlorine. We concluded that the chlorine and chloramines levels usually employed in water distribution system were not sufficient to prevent the growth and development of microbial biofilm. The combination of copper pipe slides and chloramines as the disinfectant was the most efficient combination to bring about diminished bacterial levels.