Seven stations were established in the Quanzhou Bay （24.73°-24.96°N, 118.50°-118.70°E） in China on three cruises to determine the concentrations of polycyclic aromatic hydrocarbons （PAHs） and t...Seven stations were established in the Quanzhou Bay （24.73°-24.96°N, 118.50°-118.70°E） in China on three cruises to determine the concentrations of polycyclic aromatic hydrocarbons （PAHs） and the numbers of PAH-degrading bacteria in surface sediments. Assessing the biodegradation potential of indigenous microorganisms by measuring the respiratory intensity with the addition of PAHs in sediment samples was also one of the aims of this study. The results show that the total PAH concentrations of the sediments were 99.23-345.53 ng/g dry weight （d.w.）, and the PAHs composition pattern in the sediments was dominated by phenanthrene, fluoranthene and pyrene. The numbers of phenanthrene, fluoranthene and pyrene-degrading bacteria during three cruises were 1.42×10^3-8.93×10^4 CFU/g d.w., 8.29×10^3 9.43×10^4 CFU/g d.w. and 7.05×10^3-9.43×10^4 CFU/g d.w., respectively. The addition of three model PAH compounds （phenanthrene, fluoranthene and pyrene） showed a great influence on the increasing of the microbial activity in the sediments. And there was a significant correlation among the change of respiratory activity, PAH concentration and the number of PAH-degrading bacteria. The change in respiratory activity under PAHs selective pressure could, to a certain extent, indicate the potential degradative activity of the PAH-degrading microbial community.展开更多
Conservation agriculture (CA) is one option for dealing with such a challenge, but its main difficulty in West Africa is in maintaining permanent soil cover, particularly with crop residues, due to their preferential ...Conservation agriculture (CA) is one option for dealing with such a challenge, but its main difficulty in West Africa is in maintaining permanent soil cover, particularly with crop residues, due to their preferential use for livestock fodder. The aim of our study was to determine the effect of crop residue mulching on the efficiency of cropping systems based on the principles of conservation agriculture. The experimental design was based on on-station experiments, intended to assess the specific effect of different levels of crop residue mulching on the biological and chemical soil fertility parameters, while in on-farm experiments we mainly assessed the ability of farmers to actually collect crop residues for soil cover and the associated effects on weeds and yields. The on-station experimental design was in fully randomized factorial blocks comprising five treatments and three replicates. The treatments compared the conventional system, tillage and cropping without mulching, and CA systems with 1 ton, 2 tons, and 4 tons of straw per hectare in plots of 10 m<sup>2</sup>. The effects of CA on the macrofauna, respiratory activity, and soil chemical parameters were evaluated in the 2014 and 2015 growing seasons. For the on-farm experiments, the conventional and CA practices of 15 farmers were compared to conventional practices in 2013 and 2014 in plots of 626 m<sup>2</sup>. The on-station results showed that the presence of crop residue mulching induced an increase in the density of termites. A significant release of carbon dioxide (CO<sub>2</sub>) in the CA treatments compared to the conventional treatment was also observed. For the chemical parameters (pH, N, P and K) were significantly and positively affected by mulch in the top 5 centimeters of soil. The on-farm experiments confirmed the difficulty of farmers in collecting enough biomass, with negative effects on grass cover leading to generally lower yields than conventional treatments. Other practices also affected the results, such as the maize sowing date, the gap between sowing and weeding, the gap between sowing and urea supply, the number of years of CA practices in the plot and, the gap between maize sowing and cowpea sowing. For the farmers having the human resources to collect enough crop residues for soil cover and follow the steps of the crop management sequences, it was possible to maintain yields compared to the conventional practice.展开更多
Vanadium compounds show potential in diabetes and cancer treatment, although the toxicity remains a great concern. Previous studies have shown that vanadium-induced oxidative stress affecting mitochondrial function is...Vanadium compounds show potential in diabetes and cancer treatment, although the toxicity remains a great concern. Previous studies have shown that vanadium-induced oxidative stress affecting mitochondrial function is intensively responsible for the toxicity. In this work, we investigated the effects of the vanadium compounds sodium metavanadate （NaVO3） and vanadyl acetylacetonate （VO（acac）2） on mitochondrial ROS generation and respiratory complex activities. The experimental results showed that vanadium compounds affected the ROS generation and complex activities in different patterns depending on the chemical species. NaVO3 inhibited mitochondrial complexes Ⅰ and Ⅱ activities and stimulated ROS generation at low concentration range; while VO（acac）2 promoted complex Ⅱ activity but resulted in electron leakage from the complex Ⅰ-involved pathway. The present results provide new evidence for understanding the toxicity of antidiabetic vanadium compounds.展开更多
Prenatal alcohol exposure disrupts the development of normal fetal respiratory function, but whether it perturbs respiratory rhythmical discharge activity is unclear. Furthermore, it is unknown whether the 5-hydroxytr...Prenatal alcohol exposure disrupts the development of normal fetal respiratory function, but whether it perturbs respiratory rhythmical discharge activity is unclear. Furthermore, it is unknown whether the 5-hydroxytryptamine 2A receptor（5-HT2AR） is involved in the effects of prenatal alcohol exposure. In the present study, pregnant female rats received drinking water containing alcohol at concentrations of 0%, 1%, 2%, 4%, 8% or 10%（v/v） throughout the gestation period. Slices of the medulla from 2-day-old neonatal rats were obtained to record respiratory rhythmical discharge activity. 5-HT2 AR protein and m RNA levels in the pre-B？tzinger complex of the respiratory center were measured by western blot analysis and quantitative RT-PCR, respectively. Compared with the 0% alcohol group, respiratory rhythmical discharge activity in medullary slices in the 4%, 8% and 10% alcohol groups was decreased, and the reduction was greatest in the 8% alcohol group. Respiratory rhythmical discharge activity in the 10% alcohol group was irregular. Thus, 8% was the most effective alcohol concentration at attenuating respiratory rhythmical discharge activity. These findings suggest that prenatal alcohol exposure attenuates respiratory rhythmical discharge activity in neonatal rats by downregulating 5-HT2 AR protein and m RNA levels.展开更多
Background：People experiencing strong feelings of fatigue during exercise sometimes subconsciously yell to refocus their efforts and,thus,maintain exercise performance.The present study examined the influenc of yelli...Background：People experiencing strong feelings of fatigue during exercise sometimes subconsciously yell to refocus their efforts and,thus,maintain exercise performance.The present study examined the influenc of yelling during high-intensity exercise by analysing cardiorespiratory reactions and integrated electromyography（i EMG） changes in the vastus lateralis during a cycle ergometer test.Methods：A total of 23 moderately trained people were recruited.The cycling test began with a resistance of 25 W/min,which was gradually increased.During the experimental trial,the participants were required to yell at least 3 times when they felt exhausted;during the controlled trial,they were not allowed to produce any yelling sounds.The testing order was randomly assigned and the 2 trials were completed within an interval between 3–10 days.Two-way repeated measures ANOVA was applied to analyse the differences within and between the trials,and interaction of trial and time.Results：The peak power and time to exhaustion（p〈0.01） in the yelling trial were higher than those in the control trial.However,the vastus lateralis iE MG values of both trials at peak power were not significant y different.During the yelling period at 90%–100% of the maximal effort,a significan time-by-trialinteraction（p〈0.05）wasobservedinoxygenconsumption（VO2）,CO2 production,O2 pulse,ventilation,andrespiratoryrate. Alltheabove measures showed a significan between-trial difference（p〈0.02）.However,heart rate,respiratory exchange ratio,end-tidal oxygen pressure,and ventilatory equivalent for oxygen showed only significan between-trial difference（p〈0.05）,but without interaction of trial and time.Conclusion：Yelling enhances the peak O2 pulse and VO2 and maintains CO2-exclusion efficien y during high-intensity exercise.It may enable maintaining muscle activation without stronger EMG signals being required during high-intensity exercise.展开更多
基金The National High Technology Research and Development Program ("863" Program) of China under contractNo. 2008AA09Z408the National Natural Science Foundation of China under contract No. 40576054+1 种基金the Program for Changjiang Scholars and Innovative Research Team in University under contract No. 40821063the Science and Technology Foundationof Fujian Province, China under contract No. 2008Y0061
文摘Seven stations were established in the Quanzhou Bay （24.73°-24.96°N, 118.50°-118.70°E） in China on three cruises to determine the concentrations of polycyclic aromatic hydrocarbons （PAHs） and the numbers of PAH-degrading bacteria in surface sediments. Assessing the biodegradation potential of indigenous microorganisms by measuring the respiratory intensity with the addition of PAHs in sediment samples was also one of the aims of this study. The results show that the total PAH concentrations of the sediments were 99.23-345.53 ng/g dry weight （d.w.）, and the PAHs composition pattern in the sediments was dominated by phenanthrene, fluoranthene and pyrene. The numbers of phenanthrene, fluoranthene and pyrene-degrading bacteria during three cruises were 1.42×10^3-8.93×10^4 CFU/g d.w., 8.29×10^3 9.43×10^4 CFU/g d.w. and 7.05×10^3-9.43×10^4 CFU/g d.w., respectively. The addition of three model PAH compounds （phenanthrene, fluoranthene and pyrene） showed a great influence on the increasing of the microbial activity in the sediments. And there was a significant correlation among the change of respiratory activity, PAH concentration and the number of PAH-degrading bacteria. The change in respiratory activity under PAHs selective pressure could, to a certain extent, indicate the potential degradative activity of the PAH-degrading microbial community.
文摘Conservation agriculture (CA) is one option for dealing with such a challenge, but its main difficulty in West Africa is in maintaining permanent soil cover, particularly with crop residues, due to their preferential use for livestock fodder. The aim of our study was to determine the effect of crop residue mulching on the efficiency of cropping systems based on the principles of conservation agriculture. The experimental design was based on on-station experiments, intended to assess the specific effect of different levels of crop residue mulching on the biological and chemical soil fertility parameters, while in on-farm experiments we mainly assessed the ability of farmers to actually collect crop residues for soil cover and the associated effects on weeds and yields. The on-station experimental design was in fully randomized factorial blocks comprising five treatments and three replicates. The treatments compared the conventional system, tillage and cropping without mulching, and CA systems with 1 ton, 2 tons, and 4 tons of straw per hectare in plots of 10 m<sup>2</sup>. The effects of CA on the macrofauna, respiratory activity, and soil chemical parameters were evaluated in the 2014 and 2015 growing seasons. For the on-farm experiments, the conventional and CA practices of 15 farmers were compared to conventional practices in 2013 and 2014 in plots of 626 m<sup>2</sup>. The on-station results showed that the presence of crop residue mulching induced an increase in the density of termites. A significant release of carbon dioxide (CO<sub>2</sub>) in the CA treatments compared to the conventional treatment was also observed. For the chemical parameters (pH, N, P and K) were significantly and positively affected by mulch in the top 5 centimeters of soil. The on-farm experiments confirmed the difficulty of farmers in collecting enough biomass, with negative effects on grass cover leading to generally lower yields than conventional treatments. Other practices also affected the results, such as the maize sowing date, the gap between sowing and weeding, the gap between sowing and urea supply, the number of years of CA practices in the plot and, the gap between maize sowing and cowpea sowing. For the farmers having the human resources to collect enough crop residues for soil cover and follow the steps of the crop management sequences, it was possible to maintain yields compared to the conventional practice.
基金National Natural Science Foundation of China (Grant No.20671008/20971008)
文摘Vanadium compounds show potential in diabetes and cancer treatment, although the toxicity remains a great concern. Previous studies have shown that vanadium-induced oxidative stress affecting mitochondrial function is intensively responsible for the toxicity. In this work, we investigated the effects of the vanadium compounds sodium metavanadate （NaVO3） and vanadyl acetylacetonate （VO（acac）2） on mitochondrial ROS generation and respiratory complex activities. The experimental results showed that vanadium compounds affected the ROS generation and complex activities in different patterns depending on the chemical species. NaVO3 inhibited mitochondrial complexes Ⅰ and Ⅱ activities and stimulated ROS generation at low concentration range; while VO（acac）2 promoted complex Ⅱ activity but resulted in electron leakage from the complex Ⅰ-involved pathway. The present results provide new evidence for understanding the toxicity of antidiabetic vanadium compounds.
基金the Natural Science Foundation of Henan Province in China,No.102102310156the Foundation of Xinxiang Technology Bureau in China,No.ZG14004
文摘Prenatal alcohol exposure disrupts the development of normal fetal respiratory function, but whether it perturbs respiratory rhythmical discharge activity is unclear. Furthermore, it is unknown whether the 5-hydroxytryptamine 2A receptor（5-HT2AR） is involved in the effects of prenatal alcohol exposure. In the present study, pregnant female rats received drinking water containing alcohol at concentrations of 0%, 1%, 2%, 4%, 8% or 10%（v/v） throughout the gestation period. Slices of the medulla from 2-day-old neonatal rats were obtained to record respiratory rhythmical discharge activity. 5-HT2 AR protein and m RNA levels in the pre-B？tzinger complex of the respiratory center were measured by western blot analysis and quantitative RT-PCR, respectively. Compared with the 0% alcohol group, respiratory rhythmical discharge activity in medullary slices in the 4%, 8% and 10% alcohol groups was decreased, and the reduction was greatest in the 8% alcohol group. Respiratory rhythmical discharge activity in the 10% alcohol group was irregular. Thus, 8% was the most effective alcohol concentration at attenuating respiratory rhythmical discharge activity. These findings suggest that prenatal alcohol exposure attenuates respiratory rhythmical discharge activity in neonatal rats by downregulating 5-HT2 AR protein and m RNA levels.
基金supported by a Grant-in-Aid for Scientifi Research (ISU99-04-03) from I-Shou University,Kaohsiung,Taiwan,China
文摘Background：People experiencing strong feelings of fatigue during exercise sometimes subconsciously yell to refocus their efforts and,thus,maintain exercise performance.The present study examined the influenc of yelling during high-intensity exercise by analysing cardiorespiratory reactions and integrated electromyography（i EMG） changes in the vastus lateralis during a cycle ergometer test.Methods：A total of 23 moderately trained people were recruited.The cycling test began with a resistance of 25 W/min,which was gradually increased.During the experimental trial,the participants were required to yell at least 3 times when they felt exhausted;during the controlled trial,they were not allowed to produce any yelling sounds.The testing order was randomly assigned and the 2 trials were completed within an interval between 3–10 days.Two-way repeated measures ANOVA was applied to analyse the differences within and between the trials,and interaction of trial and time.Results：The peak power and time to exhaustion（p〈0.01） in the yelling trial were higher than those in the control trial.However,the vastus lateralis iE MG values of both trials at peak power were not significant y different.During the yelling period at 90%–100% of the maximal effort,a significan time-by-trialinteraction（p〈0.05）wasobservedinoxygenconsumption（VO2）,CO2 production,O2 pulse,ventilation,andrespiratoryrate. Alltheabove measures showed a significan between-trial difference（p〈0.02）.However,heart rate,respiratory exchange ratio,end-tidal oxygen pressure,and ventilatory equivalent for oxygen showed only significan between-trial difference（p〈0.05）,but without interaction of trial and time.Conclusion：Yelling enhances the peak O2 pulse and VO2 and maintains CO2-exclusion efficien y during high-intensity exercise.It may enable maintaining muscle activation without stronger EMG signals being required during high-intensity exercise.
