Objective Striatum may be involved in depressive disorders according to the neuroimaging analysis and clinical data. However, no animal model at present supported the possible role of striatum in the pathogenesis of d...Objective Striatum may be involved in depressive disorders according to the neuroimaging analysis and clinical data. However, no animal model at present supported the possible role of striatum in the pathogenesis of depression. In the present study, we have investigated the depressive-like behavior in mice recently intoxicated with 3-nitropropionic acid (3- NP), a widely known toxin that selectively damages the striatum in the brain. Methods Mouse model was made with subacute systemic 3-NP treatment, and the depressive-like behavior was measured using the duration of immobility during forced swimming test (FST). Results When the mice at day 15 post-intoxication just totally recovered from motor deficits, the duration of immobility in FST was significantly longer than that in controls. The depressive-like behavior was not due to the fatigue or general sickness following 3-NP intoxication and could be reversed by the antidepressant, desipramine hydrochloride. In two successive FST in 24 h interval, the depressive-like behavior could be observed again in subsequent FST (at day 16 post-intoxication), and the mice presented a normal "learned helplessness". Conclusion A novel depression animal model could be established in mice during the initial period of recovery from 3-NP intoxication. The depression-like behavior might occur independently without involvement of cognitive defects, and the striatal lesions may underlie the depression-like behavior attributable to 3-NP intoxication.展开更多
Using four types of settlements in the upper reach of Minjiang River as case,we establish structural models in farmers' income of different settlement patterns based on rural household panel data to reveal the gra...Using four types of settlements in the upper reach of Minjiang River as case,we establish structural models in farmers' income of different settlement patterns based on rural household panel data to reveal the gradient effect on farmers' income and determinants.The results indicate that:(1) except the resettlement area,the incomes for farmers living in river valley,semi-mountain,and high-mountain settlements present a decreasing trend with the elevation increasing;on the contrary,their nonfarm earnings show an increasing trend with the elevation decreasing;(2) from the effect on farmers' income,there is a common feature that the nonfarm earnings and farming incomes have significant positive effects,and family size and productive expenditure have significant negative effects.One exception to this is the productive expenditure,which becomes insignificant in the model of resettlement area;(3) from the way of increasing farmers' income and alleviating poverty,there are great differences for four types of settlements in mountain areas,however,the improvement of agricultural product sales,agricultural production subsidies,the expansion for nonfarm employment,and the control of the family's size are the most effective approaches for poverty alleviation.展开更多
Whether it is necessary to reduce nitrogen(N) and/or phosphorus(P) input to mitigate lake eutrophication is controversial. The controversy stems mainly from differences in time and space in previous studies that suppo...Whether it is necessary to reduce nitrogen(N) and/or phosphorus(P) input to mitigate lake eutrophication is controversial. The controversy stems mainly from differences in time and space in previous studies that support the contrasting ideas. To test the response of phytoplankton to various combinations of nutrient control strategies in mesocosms and the possibility of reflecting the conditions in natural ecosystems with short-term experiments, a 9-month experiment was carried out in eight 800-L tanks with four nutrient level combinations(+N+P,-N+P, +N-P, and-N-P), with an 18-month whole-ecosystem experiment in eight ~800-m^2 ponds as the reference. Phytoplankton abundance was determined by P not N, regardless of the initial TN/TP level, which was in contrast to the nutrient limitation predicted by the N/P theory. Net natural N inputs were calculated to be 4.9, 6.8, 1.5, and 3.0 g in treatments +N+P,-N+P, +N-P, and-N-P, respectively, suggesting that N deficiency and P addition may promote natural N inputs to support phytoplankton development. However, the compensation process was slow, as suggested by an observed increase in TN after 3 weeks in-N+P and 2 months in-N-P in the tank experiment, and after 3 months in-N?+P and ~3 months in-N-P in our pond experiment. Obviously, such a slow process cannot be simulated in short-term experiments. The natural N inputs cannot be explained by planktonic N-fixation because N-fixing cyanobacteria were scarce, which was probably because there was a limited pool of species in the tanks. Therefore, based on our results we argue that extrapolating short-term, small-scale experiments to large natural ecosystems does not give reliable, accurate results.展开更多
In China, the tourism industry is regarded as one means of fostering local economic development. This paper tries to examine inbound tourism development in China in the last decade and analyze inbound tourism's sa...In China, the tourism industry is regarded as one means of fostering local economic development. This paper tries to examine inbound tourism development in China in the last decade and analyze inbound tourism's satisfaction of their travel experience with tourist attractions, facilities, services and price by an empirical study based on the investigation of Lanzhou, Wuhan, Guangzhou, Shanghai and Beijing. This paper discusses the demographic characteristics of visitors from Hong Kong, Macao and Taiwan, US, Korea and Japan by surveying a sample of 528 visitors in fi ve different cities. The survey showed that four provinces/autonomous region in western China ranked the top 10 popular destinations. Chinese natural landscape, culture and food were highly regarded by the tourists. At the same time, tourists expressed less satisfaction with tourist language convenience, tourist facility and nightlife in China. It was also found that only 7.4% of the tourists thought travel in China was far more than what they had paid, that 6.5% regarded they got what they paid for, and that 34.9% thought the travel cost was reasonable. Most tourists were satisfi ed with their travel experience in China; many of them would like to return to China and would like to recommend China. For the sustainable development of tourism, Chinese tourism authorities should strengthen the construction, propaganda and management of scenic spots, improve tourist facility and tourist education, especially language convenience, and strengthen the supervision of tickets, souvenir and hotel price.展开更多
Nowadays, the image construction of Hainan International Tourism Islands has been vigorously promoted. The research is going to make an empirical analysis of Hainan tourism image, adopting IPA analysis method. General...Nowadays, the image construction of Hainan International Tourism Islands has been vigorously promoted. The research is going to make an empirical analysis of Hainan tourism image, adopting IPA analysis method. Generally speaking, there is a big gap between the Hainan tourist destination and tourists' expectations. The Hainan Tourist Destination image is mainly built on natural-advantage-resource projects such as natural sceneries, air quality, and climate, etc., meanwhile, the relatively insufficient constructions of soft-wares such as tourism-related facilities, as well as the quality of tourism services, etc., are the focus of future efforts.展开更多
AIM: To study the effects of concentrated liquor from male zooid of Antheraea pernyion immunological mice.METHODS: For each experiment, 40 mice were randomly divided into normal saline group (control group) and th...AIM: To study the effects of concentrated liquor from male zooid of Antheraea pernyion immunological mice.METHODS: For each experiment, 40 mice were randomly divided into normal saline group (control group) and three tested groups that were administered different dosages of concentrated liquor from male zooid of A. pernyiand food for 15 d. The typical FSR and HC50 value, monocybe-phagocytic exponent Kand emendated monocyte-phagocytic exponent were determined and calculated respectively.RESULTS: Alter 24 and 48 h, the FSR values of the three tested groups improved significantly in comparison to the conlyol group by variance analysis. The HCso values showed a significant difference between the high dosage group and the control group, as well as between the high dosage group and other two bested groups. The monocyte-phagocytic exponent Kand emendated exponent α showed rising tendencies, but no significant differences were found by variance analysis.CONCLUSION: The concentrated liquor from male zooid of A. pemyican significantly enhance cellular and humoral immune function in mice, but has no distinct influence on the monocyte-phagocytic system in mice.展开更多
The inactivation of Cyclops with currently available oxidants such as chlorine, chlorine dioxide, ozone and potassium permanganate was investigated and reported under various working conditions of different oxidant do...The inactivation of Cyclops with currently available oxidants such as chlorine, chlorine dioxide, ozone and potassium permanganate was investigated and reported under various working conditions of different oxidant dosage, organic substance content and pH value. The removal efficiency of Cyclops by predosing chlorine dioxide in water treatment process was comprehensively compared with that of the conventional prechlorination process. The results showed that chlorine dioxide might be most effective to inactivate Cyclops than other oxidants and its effect was less influenced by external conditions. Cyclops could be effectively inactivated by chlorine dioxide preoxidation and be thoroughly removed from water by chlorine dioxide preoxidation cooperating with routine clarification process, i.e. flocculation, sedimentation and filtration.展开更多
The decrease of wind velocity (wake losses) in downstream area of wind turbine is generally quantified using wake models. The overall estimated power of wind farm varies according to reliability of wake model used, ...The decrease of wind velocity (wake losses) in downstream area of wind turbine is generally quantified using wake models. The overall estimated power of wind farm varies according to reliability of wake model used, however it's unclear which model is most appropriate and able to give a high performance in predicting wind velocity deficit. In this subject, a qualification of three analytical wake models (Jensen, lshihara and Frandsen) based on three principal criteria is presented in this paper: (i) the parsimony which characterizes the inverse of model complexity, (ii) the accuracy of estimation in which wake model is compared with the experimental data and (iii) imprecision that is related to assumptions and uncertainty on the value of variables considered in each model. This qualitative analysis shows the inability of wake models to predict wind velocity deficit due to the big uncertainty of variables considered and it sensitivity to wind farm characteristic.展开更多
The discrete excitation-emission-matrix fluorescence spectra (EEMS) at 12 excitation wavelengths (400, 430, 450, 460, 470, 490, 500, 510, 525, 550, 570, and 590 nm) and emission wavelengths ranging from 600-750 nm wer...The discrete excitation-emission-matrix fluorescence spectra (EEMS) at 12 excitation wavelengths (400, 430, 450, 460, 470, 490, 500, 510, 525, 550, 570, and 590 nm) and emission wavelengths ranging from 600-750 nm were determined for 43 phytoplankton species. A two-rank fluorescence spectra database was established by wavelet analysis and a fluorometric discrimination technique for determining phytoplankton population was developed. For laboratory simulatively mixed samples, the samples mixed from 43 algal species (the algae of one division accounted for 25%, 50%, 75%, 85%, and 100% of the gross biomass, respectively), the average discrimination rates at the level of division were 65.0%, 87.5%, 98.6%, 99.0%, and 99.1%, with average relative contents of 18.9%, 44.5%, 68.9%, 73.4%, and 82.9%, respectively; the samples mixed from 32 red tide algal species (the dominant species accounted for 60%, 70%, 80%, 90%, and 100% of the gross biomass, respectively), the average correct discrimination rates of the dominant species at the level of genus were 63.3%, 74.2%, 78.8%, 83.4%, and 79.4%, respectively. For the 81 laboratory mixed samples with the dominant species accounting for 75% of the gross biomass (chlorophyll), the discrimination rates of the dominant species were 95.1% and 72.8% at the level of division and genus, respectively. For the 12 samples collected from the mesocosm experiment in Maidao Bay of Qingdao in August 2007, the dominant species of the 11 samples were recognized at the division level and the dominant species of four of the five samples in which the dominant species accounted for more than 80% of the gross biomass were discriminated at the genus level; for the 12 samples obtained from Jiaozhou Bay in August 2007, the dominant species of all the 12 samples were recognized at the division level. The technique can be directly applied to fluorescence spectrophotometers and to the developing of an in situ algae fluorescence auto-analyzer for phytoplankton population.展开更多
The drop structure will fail as a result of local scoring downstream.This paper discusses the influence of a drop structures' upstream slope to local scour.Empirical equations of the scour hole were developed by l...The drop structure will fail as a result of local scoring downstream.This paper discusses the influence of a drop structures' upstream slope to local scour.Empirical equations of the scour hole were developed by laboratory experiment,theoretical assumptions,and regression analysis.These equations include the maximum scour depth and length during the scouring period,the maximum equilibrium scour depth and length,and the unit width scour rate.The four channel slopes(0%,2%,4%,and 6%) before the drop structure has been included in the analysis.A series of laboratory experiments were conducted to obtain 48 groups of experiments and 419 scour hole profiles during the scouring period.The material used in the scour section is uniform non-cohesive and with a median diameter of d50 = 0.5 mm.The results have been used to develop empirical equations via regression analysis to determine the coefficients of theoretical equations.The high correlation coefficient indicates that the equations developed in this study are suitable for verifying the characteristics of a scour hole at drop structure in the sloped channel.The semi-empirical equation is more accurate than the empirical equation.Compared to a horizontal channel,a sloped channel tends to cause a greater equilibriummaximum scour length,shorter equilibrium maximum scour depth,and faster unit-wide scour rate.展开更多
In this paper, we take Tourism Vocational English for example, through the analysis of the problems and contradictions in vocational high school practice, around the vocational training objectives, make in-depth discu...In this paper, we take Tourism Vocational English for example, through the analysis of the problems and contradictions in vocational high school practice, around the vocational training objectives, make in-depth discussion of reform and innovation of graduation comprehensive practice mode from the overall design, stage promotion and process management.展开更多
The tourism consumption behavior of the young people has significant effect on the present social tourism consumption behavior. Intensifying the research on tourism consumption behavior of the youth group helps to exp...The tourism consumption behavior of the young people has significant effect on the present social tourism consumption behavior. Intensifying the research on tourism consumption behavior of the youth group helps to explore the hot spot of tourism consumption, and designing specific marketing programs and taping into consumption potential is the key to market development. The research takes the university students in the youth group as an example to analyze the features and difference of tourism consumption behavior and observe tourism consumption marketing of the university students, for providing reference for the expansion of tourism market.展开更多
Depression is a chronic,recurring and potentially life-threatening illness that affects up to 20%of the population across the world.Despite its prevalence and considerable impact on human,little is known about its pat...Depression is a chronic,recurring and potentially life-threatening illness that affects up to 20%of the population across the world.Despite its prevalence and considerable impact on human,little is known about its pathogenesis.One of the major reasons is the restricted availability of validated animal models due to the absence of consensus on the pathology and etiology of depression.Besides,some core symptoms such as depressed mood,feeling of worthlessness,and recurring thoughts of death or suicide,are impossible to be modeled on laboratory animals.Currently,the criteria for identifying animal models of depression rely on either of the 2 principles:actions of known antidepressants and responses to stress.This review mainly focuses on the most widely used animal models of depression,including learned helplessness,chronic mild stress,and social defeat paradigms.Also,the behavioral tests for screening antidepressants,such as forced swimming test and tail suspension test,are also discussed.The advantages and major drawbacks of each model are evaluated.In prospective,new techniques that will be beneficial for developing novel animal models or detecting depression are discussed.展开更多
The antidepressant effects of the flavonoid-rieh fraction of Monodora tenuifolia seed extract were examined by assess- ing the extent of attenuation of behavioural alterations and oxidative damage in the rats that wer...The antidepressant effects of the flavonoid-rieh fraction of Monodora tenuifolia seed extract were examined by assess- ing the extent of attenuation of behavioural alterations and oxidative damage in the rats that were stressed by forced swim test. Com- pared with the model control group, the altered behavioural parameters were attenuated significantly (P 〈 0.05) in the group treated with the flavonoid-rich fraction (100 and 200 mg·kg^-1), comparable to the group treated with the standard drug, fluoxetine (10 mg·kg^-1). The flavonoid-rich fraction and fluoxetine improved significantly (P 〈 0.05) the activities of the antioxidant enzymes such as superoxide dismutase and catalase as well as other biochemical parameters such as reduced glutathione, protein, and nitrite in the brain of the stressed rats. These results suggested that the flavonoid-rich fraction of Monodora tenuifolia seed extract exerted the antidepres- sant-like effects which could be useful in the management of stress induced disease.展开更多
OBJECTIVE:Angelica archangelica Linn.is widely used in food and liquor preparations and also in Kashmiri folk medicine to reduce anxiety.We evaluated the anxiolytic effect of successive extracts of A.archangelica linn...OBJECTIVE:Angelica archangelica Linn.is widely used in food and liquor preparations and also in Kashmiri folk medicine to reduce anxiety.We evaluated the anxiolytic effect of successive extracts of A.archangelica linn.(SAE) on rats tested in the elevated T-maze test(an animal model of generalized anxiety) at doses that exhibit antidepressant-like activity in humans.METHODS:A.archangelica(1 kg) was subjected to successive extraction in a soxhlet apparatus with solvents [petroleum ether(40-60℃),chloroform,ethyl acetate,methanol and decoction with water] in order of increasing polarity(yield:6.9%,7.3%,5.1%,11.88% and 8.2% w/w,respectively).SAE were evaluated for anxiolytic effects using the elevated T-maze and forced swimming tests in rats.RESULTS:Oral dosing of diazepam(1 mg/kg) and extracts(50,100 and 200 mg/kg) clearly showed an anxiolytic-like profile in the elevated T-maze test:it increased one-way escape and decreased inhibitory avoidance on the first,third and seventh day.In the forced swimming test,imipramine and SAE showed antidepressant-and anxiolytic-like effects as reflected by increased climbing time,swimming time and decreased immobility time on the first,third and seventh day.Aqueous and methanol extracts showed the most,petroleum ether(40-60℃) and chloroform intermediate,and ethyl acetate the least anxiolytic activity(*P<0.05,**P<0.01,***P< 0.001) in both models.CONCLUSIONS:These results suggest the anti-anxiety activity of various extracts of A.archangelica and strongly justify its use in traditional Indian medicine for the treatment of anxiety.展开更多
Fish behavior can be altered by contaminants. There is an extensive literature on laboratory behavioral assays, with many chemicals impairing feeding or predator avoidance. However, there is not extensive work on fish...Fish behavior can be altered by contaminants. There is an extensive literature on laboratory behavioral assays, with many chemicals impairing feeding or predator avoidance. However, there is not extensive work on fishes that live in contami- nated environments. Therefore, we then review our recent research on feeding and trophic relations of populations from contami- nated estuaries compared with relatively unpolluted sites. The mummichog Fundulus heteroclitus, is a non-migratory fish; those from more contaminated areas are poor predators and slower to capture active prey (grass shrimp, Palaemonetes pugio). In the field, they consume much detritus and sediment, which is not nutritious. They are less active than fish from cleaner sites and more vulnerable to predation. They have altered thyroid glands and neurotransmitter levels, which may underlie altered behaviors Fish from the reference site kept in tanks with sediment and food from the polluted site showed bioaccumulation and reduced prey capture after two months, although fish from the polluted site did not show significant improvement when maintained in a clean environment. Poor nutrition and predator avoidance may be responsible for their being smaller and having a shorter life span than reference fish. Bluefish Pomatomus saltatrix, are a marine species in which the young-of-the-year spend their first summer in es- tuaries. We found bioaccumulation of contaminants and reduced activity, schooling, and feeding in young-of-the-year bluefish from a relatively unpolluted site that were fed prey fish from a contaminated site. They also had altered thyroid glands and neuro- transmitter levels. Many field-caught specimens had empty stomachs, which is rare in this species. In the fall, when they migrate back out to the ocean, they are smaller, slower, and more likely to starve or to be eaten than those that spent their summer in cleaner estuaries [Current Zoology 58 (1): 9-20, 2012].展开更多
文摘Objective Striatum may be involved in depressive disorders according to the neuroimaging analysis and clinical data. However, no animal model at present supported the possible role of striatum in the pathogenesis of depression. In the present study, we have investigated the depressive-like behavior in mice recently intoxicated with 3-nitropropionic acid (3- NP), a widely known toxin that selectively damages the striatum in the brain. Methods Mouse model was made with subacute systemic 3-NP treatment, and the depressive-like behavior was measured using the duration of immobility during forced swimming test (FST). Results When the mice at day 15 post-intoxication just totally recovered from motor deficits, the duration of immobility in FST was significantly longer than that in controls. The depressive-like behavior was not due to the fatigue or general sickness following 3-NP intoxication and could be reversed by the antidepressant, desipramine hydrochloride. In two successive FST in 24 h interval, the depressive-like behavior could be observed again in subsequent FST (at day 16 post-intoxication), and the mice presented a normal "learned helplessness". Conclusion A novel depression animal model could be established in mice during the initial period of recovery from 3-NP intoxication. The depression-like behavior might occur independently without involvement of cognitive defects, and the striatal lesions may underlie the depression-like behavior attributable to 3-NP intoxication.
基金Funding was provided for China regional research by the Key Program of the Chinese Academy of Sciences (Grant No. KZZD-EW-06-03)
文摘Using four types of settlements in the upper reach of Minjiang River as case,we establish structural models in farmers' income of different settlement patterns based on rural household panel data to reveal the gradient effect on farmers' income and determinants.The results indicate that:(1) except the resettlement area,the incomes for farmers living in river valley,semi-mountain,and high-mountain settlements present a decreasing trend with the elevation increasing;on the contrary,their nonfarm earnings show an increasing trend with the elevation decreasing;(2) from the effect on farmers' income,there is a common feature that the nonfarm earnings and farming incomes have significant positive effects,and family size and productive expenditure have significant negative effects.One exception to this is the productive expenditure,which becomes insignificant in the model of resettlement area;(3) from the way of increasing farmers' income and alleviating poverty,there are great differences for four types of settlements in mountain areas,however,the improvement of agricultural product sales,agricultural production subsidies,the expansion for nonfarm employment,and the control of the family's size are the most effective approaches for poverty alleviation.
基金Supported by the State Key Laboratory of Freshwater Ecology and Biotechnology(Nos.2014FB14,2011FBZ14)Science and Technology Support Program of Hubei Province(No.2015BBA225)the Youth Innovation Association of Chinese Academy of Sciences(No.2014312)to WANG Haijun
文摘Whether it is necessary to reduce nitrogen(N) and/or phosphorus(P) input to mitigate lake eutrophication is controversial. The controversy stems mainly from differences in time and space in previous studies that support the contrasting ideas. To test the response of phytoplankton to various combinations of nutrient control strategies in mesocosms and the possibility of reflecting the conditions in natural ecosystems with short-term experiments, a 9-month experiment was carried out in eight 800-L tanks with four nutrient level combinations(+N+P,-N+P, +N-P, and-N-P), with an 18-month whole-ecosystem experiment in eight ~800-m^2 ponds as the reference. Phytoplankton abundance was determined by P not N, regardless of the initial TN/TP level, which was in contrast to the nutrient limitation predicted by the N/P theory. Net natural N inputs were calculated to be 4.9, 6.8, 1.5, and 3.0 g in treatments +N+P,-N+P, +N-P, and-N-P, respectively, suggesting that N deficiency and P addition may promote natural N inputs to support phytoplankton development. However, the compensation process was slow, as suggested by an observed increase in TN after 3 weeks in-N+P and 2 months in-N-P in the tank experiment, and after 3 months in-N?+P and ~3 months in-N-P in our pond experiment. Obviously, such a slow process cannot be simulated in short-term experiments. The natural N inputs cannot be explained by planktonic N-fixation because N-fixing cyanobacteria were scarce, which was probably because there was a limited pool of species in the tanks. Therefore, based on our results we argue that extrapolating short-term, small-scale experiments to large natural ecosystems does not give reliable, accurate results.
文摘In China, the tourism industry is regarded as one means of fostering local economic development. This paper tries to examine inbound tourism development in China in the last decade and analyze inbound tourism's satisfaction of their travel experience with tourist attractions, facilities, services and price by an empirical study based on the investigation of Lanzhou, Wuhan, Guangzhou, Shanghai and Beijing. This paper discusses the demographic characteristics of visitors from Hong Kong, Macao and Taiwan, US, Korea and Japan by surveying a sample of 528 visitors in fi ve different cities. The survey showed that four provinces/autonomous region in western China ranked the top 10 popular destinations. Chinese natural landscape, culture and food were highly regarded by the tourists. At the same time, tourists expressed less satisfaction with tourist language convenience, tourist facility and nightlife in China. It was also found that only 7.4% of the tourists thought travel in China was far more than what they had paid, that 6.5% regarded they got what they paid for, and that 34.9% thought the travel cost was reasonable. Most tourists were satisfi ed with their travel experience in China; many of them would like to return to China and would like to recommend China. For the sustainable development of tourism, Chinese tourism authorities should strengthen the construction, propaganda and management of scenic spots, improve tourist facility and tourist education, especially language convenience, and strengthen the supervision of tickets, souvenir and hotel price.
文摘Nowadays, the image construction of Hainan International Tourism Islands has been vigorously promoted. The research is going to make an empirical analysis of Hainan tourism image, adopting IPA analysis method. Generally speaking, there is a big gap between the Hainan tourist destination and tourists' expectations. The Hainan Tourist Destination image is mainly built on natural-advantage-resource projects such as natural sceneries, air quality, and climate, etc., meanwhile, the relatively insufficient constructions of soft-wares such as tourism-related facilities, as well as the quality of tourism services, etc., are the focus of future efforts.
基金Supported by the National Natural Science Foundation of China, No. 30472260
文摘AIM: To study the effects of concentrated liquor from male zooid of Antheraea pernyion immunological mice.METHODS: For each experiment, 40 mice were randomly divided into normal saline group (control group) and three tested groups that were administered different dosages of concentrated liquor from male zooid of A. pernyiand food for 15 d. The typical FSR and HC50 value, monocybe-phagocytic exponent Kand emendated monocyte-phagocytic exponent were determined and calculated respectively.RESULTS: Alter 24 and 48 h, the FSR values of the three tested groups improved significantly in comparison to the conlyol group by variance analysis. The HCso values showed a significant difference between the high dosage group and the control group, as well as between the high dosage group and other two bested groups. The monocyte-phagocytic exponent Kand emendated exponent α showed rising tendencies, but no significant differences were found by variance analysis.CONCLUSION: The concentrated liquor from male zooid of A. pemyican significantly enhance cellular and humoral immune function in mice, but has no distinct influence on the monocyte-phagocytic system in mice.
基金Supported by the High Technology Research and Development Programme of China (No.2002AA601140) and the Natural Science Foundation of Heilongjiang Province (No.QC03C17).
文摘The inactivation of Cyclops with currently available oxidants such as chlorine, chlorine dioxide, ozone and potassium permanganate was investigated and reported under various working conditions of different oxidant dosage, organic substance content and pH value. The removal efficiency of Cyclops by predosing chlorine dioxide in water treatment process was comprehensively compared with that of the conventional prechlorination process. The results showed that chlorine dioxide might be most effective to inactivate Cyclops than other oxidants and its effect was less influenced by external conditions. Cyclops could be effectively inactivated by chlorine dioxide preoxidation and be thoroughly removed from water by chlorine dioxide preoxidation cooperating with routine clarification process, i.e. flocculation, sedimentation and filtration.
文摘The decrease of wind velocity (wake losses) in downstream area of wind turbine is generally quantified using wake models. The overall estimated power of wind farm varies according to reliability of wake model used, however it's unclear which model is most appropriate and able to give a high performance in predicting wind velocity deficit. In this subject, a qualification of three analytical wake models (Jensen, lshihara and Frandsen) based on three principal criteria is presented in this paper: (i) the parsimony which characterizes the inverse of model complexity, (ii) the accuracy of estimation in which wake model is compared with the experimental data and (iii) imprecision that is related to assumptions and uncertainty on the value of variables considered in each model. This qualitative analysis shows the inability of wake models to predict wind velocity deficit due to the big uncertainty of variables considered and it sensitivity to wind farm characteristic.
基金supported by National High-Tech Research and Development Program of China (863 Program)(No.2009AA063005)Natural Science Foundation of Shandong Province (No.ZR2009EM001)
文摘The discrete excitation-emission-matrix fluorescence spectra (EEMS) at 12 excitation wavelengths (400, 430, 450, 460, 470, 490, 500, 510, 525, 550, 570, and 590 nm) and emission wavelengths ranging from 600-750 nm were determined for 43 phytoplankton species. A two-rank fluorescence spectra database was established by wavelet analysis and a fluorometric discrimination technique for determining phytoplankton population was developed. For laboratory simulatively mixed samples, the samples mixed from 43 algal species (the algae of one division accounted for 25%, 50%, 75%, 85%, and 100% of the gross biomass, respectively), the average discrimination rates at the level of division were 65.0%, 87.5%, 98.6%, 99.0%, and 99.1%, with average relative contents of 18.9%, 44.5%, 68.9%, 73.4%, and 82.9%, respectively; the samples mixed from 32 red tide algal species (the dominant species accounted for 60%, 70%, 80%, 90%, and 100% of the gross biomass, respectively), the average correct discrimination rates of the dominant species at the level of genus were 63.3%, 74.2%, 78.8%, 83.4%, and 79.4%, respectively. For the 81 laboratory mixed samples with the dominant species accounting for 75% of the gross biomass (chlorophyll), the discrimination rates of the dominant species were 95.1% and 72.8% at the level of division and genus, respectively. For the 12 samples collected from the mesocosm experiment in Maidao Bay of Qingdao in August 2007, the dominant species of the 11 samples were recognized at the division level and the dominant species of four of the five samples in which the dominant species accounted for more than 80% of the gross biomass were discriminated at the genus level; for the 12 samples obtained from Jiaozhou Bay in August 2007, the dominant species of all the 12 samples were recognized at the division level. The technique can be directly applied to fluorescence spectrophotometers and to the developing of an in situ algae fluorescence auto-analyzer for phytoplankton population.
基金the research support from Ministry of Science and Technology of Chinese Taipei,with the project no.104-2313-B-343-001
文摘The drop structure will fail as a result of local scoring downstream.This paper discusses the influence of a drop structures' upstream slope to local scour.Empirical equations of the scour hole were developed by laboratory experiment,theoretical assumptions,and regression analysis.These equations include the maximum scour depth and length during the scouring period,the maximum equilibrium scour depth and length,and the unit width scour rate.The four channel slopes(0%,2%,4%,and 6%) before the drop structure has been included in the analysis.A series of laboratory experiments were conducted to obtain 48 groups of experiments and 419 scour hole profiles during the scouring period.The material used in the scour section is uniform non-cohesive and with a median diameter of d50 = 0.5 mm.The results have been used to develop empirical equations via regression analysis to determine the coefficients of theoretical equations.The high correlation coefficient indicates that the equations developed in this study are suitable for verifying the characteristics of a scour hole at drop structure in the sloped channel.The semi-empirical equation is more accurate than the empirical equation.Compared to a horizontal channel,a sloped channel tends to cause a greater equilibriummaximum scour length,shorter equilibrium maximum scour depth,and faster unit-wide scour rate.
文摘In this paper, we take Tourism Vocational English for example, through the analysis of the problems and contradictions in vocational high school practice, around the vocational training objectives, make in-depth discussion of reform and innovation of graduation comprehensive practice mode from the overall design, stage promotion and process management.
文摘The tourism consumption behavior of the young people has significant effect on the present social tourism consumption behavior. Intensifying the research on tourism consumption behavior of the youth group helps to explore the hot spot of tourism consumption, and designing specific marketing programs and taping into consumption potential is the key to market development. The research takes the university students in the youth group as an example to analyze the features and difference of tourism consumption behavior and observe tourism consumption marketing of the university students, for providing reference for the expansion of tourism market.
文摘Depression is a chronic,recurring and potentially life-threatening illness that affects up to 20%of the population across the world.Despite its prevalence and considerable impact on human,little is known about its pathogenesis.One of the major reasons is the restricted availability of validated animal models due to the absence of consensus on the pathology and etiology of depression.Besides,some core symptoms such as depressed mood,feeling of worthlessness,and recurring thoughts of death or suicide,are impossible to be modeled on laboratory animals.Currently,the criteria for identifying animal models of depression rely on either of the 2 principles:actions of known antidepressants and responses to stress.This review mainly focuses on the most widely used animal models of depression,including learned helplessness,chronic mild stress,and social defeat paradigms.Also,the behavioral tests for screening antidepressants,such as forced swimming test and tail suspension test,are also discussed.The advantages and major drawbacks of each model are evaluated.In prospective,new techniques that will be beneficial for developing novel animal models or detecting depression are discussed.
基金supported by the Tertiary Education Trust Fund,Nigeria with grant number 2012
文摘The antidepressant effects of the flavonoid-rieh fraction of Monodora tenuifolia seed extract were examined by assess- ing the extent of attenuation of behavioural alterations and oxidative damage in the rats that were stressed by forced swim test. Com- pared with the model control group, the altered behavioural parameters were attenuated significantly (P 〈 0.05) in the group treated with the flavonoid-rich fraction (100 and 200 mg·kg^-1), comparable to the group treated with the standard drug, fluoxetine (10 mg·kg^-1). The flavonoid-rich fraction and fluoxetine improved significantly (P 〈 0.05) the activities of the antioxidant enzymes such as superoxide dismutase and catalase as well as other biochemical parameters such as reduced glutathione, protein, and nitrite in the brain of the stressed rats. These results suggested that the flavonoid-rich fraction of Monodora tenuifolia seed extract exerted the antidepres- sant-like effects which could be useful in the management of stress induced disease.
文摘OBJECTIVE:Angelica archangelica Linn.is widely used in food and liquor preparations and also in Kashmiri folk medicine to reduce anxiety.We evaluated the anxiolytic effect of successive extracts of A.archangelica linn.(SAE) on rats tested in the elevated T-maze test(an animal model of generalized anxiety) at doses that exhibit antidepressant-like activity in humans.METHODS:A.archangelica(1 kg) was subjected to successive extraction in a soxhlet apparatus with solvents [petroleum ether(40-60℃),chloroform,ethyl acetate,methanol and decoction with water] in order of increasing polarity(yield:6.9%,7.3%,5.1%,11.88% and 8.2% w/w,respectively).SAE were evaluated for anxiolytic effects using the elevated T-maze and forced swimming tests in rats.RESULTS:Oral dosing of diazepam(1 mg/kg) and extracts(50,100 and 200 mg/kg) clearly showed an anxiolytic-like profile in the elevated T-maze test:it increased one-way escape and decreased inhibitory avoidance on the first,third and seventh day.In the forced swimming test,imipramine and SAE showed antidepressant-and anxiolytic-like effects as reflected by increased climbing time,swimming time and decreased immobility time on the first,third and seventh day.Aqueous and methanol extracts showed the most,petroleum ether(40-60℃) and chloroform intermediate,and ethyl acetate the least anxiolytic activity(*P<0.05,**P<0.01,***P< 0.001) in both models.CONCLUSIONS:These results suggest the anti-anxiety activity of various extracts of A.archangelica and strongly justify its use in traditional Indian medicine for the treatment of anxiety.
文摘Fish behavior can be altered by contaminants. There is an extensive literature on laboratory behavioral assays, with many chemicals impairing feeding or predator avoidance. However, there is not extensive work on fishes that live in contami- nated environments. Therefore, we then review our recent research on feeding and trophic relations of populations from contami- nated estuaries compared with relatively unpolluted sites. The mummichog Fundulus heteroclitus, is a non-migratory fish; those from more contaminated areas are poor predators and slower to capture active prey (grass shrimp, Palaemonetes pugio). In the field, they consume much detritus and sediment, which is not nutritious. They are less active than fish from cleaner sites and more vulnerable to predation. They have altered thyroid glands and neurotransmitter levels, which may underlie altered behaviors Fish from the reference site kept in tanks with sediment and food from the polluted site showed bioaccumulation and reduced prey capture after two months, although fish from the polluted site did not show significant improvement when maintained in a clean environment. Poor nutrition and predator avoidance may be responsible for their being smaller and having a shorter life span than reference fish. Bluefish Pomatomus saltatrix, are a marine species in which the young-of-the-year spend their first summer in es- tuaries. We found bioaccumulation of contaminants and reduced activity, schooling, and feeding in young-of-the-year bluefish from a relatively unpolluted site that were fed prey fish from a contaminated site. They also had altered thyroid glands and neuro- transmitter levels. Many field-caught specimens had empty stomachs, which is rare in this species. In the fall, when they migrate back out to the ocean, they are smaller, slower, and more likely to starve or to be eaten than those that spent their summer in cleaner estuaries [Current Zoology 58 (1): 9-20, 2012].