With regard to brain acetylcholinesterase and acetylcholine and serum triiodothyronine(T_3) and thyroxine(T_4)profiles,a biphasic response pattern was elicited in Channa punctatus chroni- cally exposed to nonlethal do...With regard to brain acetylcholinesterase and acetylcholine and serum triiodothyronine(T_3) and thyroxine(T_4)profiles,a biphasic response pattern was elicited in Channa punctatus chroni- cally exposed to nonlethal doses of locally used pesticides,namely,Metacid-50 and Carbaryl. Data revealed that these xenobiotics caused significant inhibition of brain acetylcholinesterase activity and a decrease in thyroxine level accompanied by a concurrent increase in acetylcholine accumulation and T_3 level.It is surmised that Metacid-50 and Carbaryl influence both neural and hormonal functions.1989 Academic Press.Inc.展开更多
One of the significant consequences of the climate change predicted for the next decades is the sea and ocean level rise.The coastal zone of Mohammedia (Morocco),a site of significant socio-economic activeties largely...One of the significant consequences of the climate change predicted for the next decades is the sea and ocean level rise.The coastal zone of Mohammedia (Morocco),a site of significant socio-economic activeties largely open to the Atlantic Ocean,is thus confronted with hydrodynamic agents and a possible sea level rise,whose impacts will result in an immersion of the low topography areas。展开更多
The study focused on the impacts of climate change on the farmer and the farming families in Niger Delta Region of Nigeria. The study specifically evaluated the perceived resultant situations attributed to climate cha...The study focused on the impacts of climate change on the farmer and the farming families in Niger Delta Region of Nigeria. The study specifically evaluated the perceived resultant situations attributed to climate change to determine the extent of impacts of climate change on the farmer and the farming families and also explored adoptable strategies for coping with the situations. The study adopted descriptive survey research design. Two research questions and two hypotheses guided the study. The population for the study was 246,909 respondents made up of farmers and extension workers who are registered with the State Ministries of Agriculture. Out of the nine Niger Delta states, Bayelsa and Delta states were randomly chosen for the study. Proportionate stratified random sampling technique was used to select a sample size of 5,038 respondents. Structured questionnaire and interview were used to collect data. The instruments were validated by three experts. Cronbach Alpha method was used to determine the internal consistency of the questionnaire items which yielded a coefficient of 0.81. The Statistical Product and Service Solutions (SPSS v 20.0) was employed for data analysis. The statistical tools used for data analysis were weighted mean to answer research questions and standard deviation to validate the closeness of the respondents from the mean and from each other in their responses while t-test was used to test the null hypotheses. The findings of the study revealed that the extent of impacts of climate change on farmers and the farming families in Niger Delta region of Nigeria are moderate. Findings further revealed that climate change has led to increased poverty level and raised cost of production (input and labour cost) as indicated by the farmers. The study recommends that farmers in the region should be encouraged by providing incentives and subsidizing inputs for them by Federal and State governments as well as other non-governmental organizations, as this will go a long way in improving production especially as most farmers agree to continue cultivation even with the observed impacts.展开更多
Purpose: This paper describes an alternative way of assessing journals considering a broader perspective of its impact. The Area-based connectedness(ABC) to society of journals applied here contributes to the assessme...Purpose: This paper describes an alternative way of assessing journals considering a broader perspective of its impact. The Area-based connectedness(ABC) to society of journals applied here contributes to the assessment of the dissemination task of journals but with more data it may also contribute to the assessment of other missions.Design/methodology/approach: The ABC approach assesses the performance of research actors, in this case journals, considering the characteristics of the research areas in which they are active. Each paper in a journal inherits the characteristics of its area. These areas are defined by a publication-based classification. The characteristics of areas relate to 5 dimensions of connectedness to society(news, policy, industrial R&D, technology and local interest) and are calculated by bibliometric indicators and social media metrics. Findings: In the paper, I illustrate the approach by showing the results for a few journals. They illustrate the diverse profiles that journals may have. We are able to provide a profile for each journal in the Web of Science database. The profiles we present show an appropriate view on the journals’ societal connectedness.Research limitations: The classification I apply to perform the analyses is a CWTS in house classification based on Web of Science data. As such the application depends on the(updates of) that system. The classification is available at www.leidenranking.com.Practical implications: The dimensions of connectedness discussed in this paper relate to the dissemination task of journals but further development of this method may provide more options to monitor the tasks/mission of journals. Originality/value: The ABC approach is a unique way to assess performance or impact of research actors considering the characteristics of the areas in which output is published and as such less prone to manipulation or gaming.展开更多
The impacts of climate change on rice yield in China from 1961 to 2010 were studied in this paper, based on the provincial data, in order to develop scientiifc countermeasures. The results indicated that increase of a...The impacts of climate change on rice yield in China from 1961 to 2010 were studied in this paper, based on the provincial data, in order to develop scientiifc countermeasures. The results indicated that increase of average temperature improved single cropping rice production on national level by up to 11%relative to the average over the study period, however, it resulted in an overall loss of double cropping rice by up to 1.9%. The decrease of diurnal temperature range （DTR） in the major producing regions caused the decrease by up to 3.0%for single cropping rice production and 2.0%for double cropping rice production. Moreover, the contribution of precipitation change reached about 6.2%for single cropping rice production, but no signiifcant effect for double cropping rice production in recent 50 years.展开更多
A splashing crown is commonly observed when a high-speed drop impacts a liquid film. The influence of the liquid viscosity on the crown＇s evolution is not yet clear. We review several existing theories of this proble...A splashing crown is commonly observed when a high-speed drop impacts a liquid film. The influence of the liquid viscosity on the crown＇s evolution is not yet clear. We review several existing theories of this problem, and carry out a series of numerical simulations. We find that a three-segment model can describe the crown＇s motion. In the very early stage when the crown is barely visible, the influence of viscosity is small. Later, a shallow water approach used in most existing models is applicable as long as the initial conditions are formulated properly. They depend on viscous dissipation in the intermediate period. Preliminary estimation based on a dissipation function is proposed to characterize the influence of viscosity in this problem.展开更多
One of the clear signals of the ongoing climate change is sea level rise (SLR). Normal oceanic tides superimposed on a rising sea level and coastal flooding will affect many coastal communities. An international colla...One of the clear signals of the ongoing climate change is sea level rise (SLR). Normal oceanic tides superimposed on a rising sea level and coastal flooding will affect many coastal communities. An international collaboration among Brazil, the United Kingdom, and the United States was designed to evaluate local decision making processes and to open space for local urban managers to reflect on possible actions toward adaption to sea level rise given the historical constraints imposed by administrative and institutional structures. This project focused on the processes that shape adaptation of three coastal communities in three countries. It worked jointly with these communities in defining the problem, examining risks, and understanding the benefits and obstacles that may hinder implementation of adaptation options. The framework was co-designed by an interdisciplinary team that incorporated social and natural scientists from the three countries, including local government officials. The study addressed 1) evaluation of adaptive capacity through participant surveys and 2) physical and cost impact simulations using geospatial models of the built infrastructure and implementation of adaptation options under different hazard scenarios, including 50 and 100-year sea level rise projections and severe storms. Based on the surveys’ results, there is a clear sense of the awareness of each community of the risk of floods due to intense storms, and of the usefulness of engaging early in a process that promotes the understanding of risks, impacts, and costs. A majority of workshop participants prioritized pursuing physical and green infrastructure actions now or within coming years or decades. A positive common aspect of the three sites was the commitment shown by the stakeholders in taking part in the process and evaluating which adaptation measures could be more effective in their cities. While in the US and UK structural solutions and voluntary buyouts were prioritized for the future, Brazil prioritized structural solutions and ecosystems restoration and not voluntary buyouts. All of these are choices to increase resiliency against sea level rise that have a high benefit-cost ratio. The Adaptive Capacity Index (ACI) results illustrate barriers to adaptation action, including technical, economic and political issues that reveal inequalities in adaptive capacity among case studies.展开更多
A level set method of non-uniform grids is used to simulate the whole evolution of a cavitation bubble, including its growth, collapse and rebound near a rigid wall. Single-phase Navier-Stokes equation in the liquid r...A level set method of non-uniform grids is used to simulate the whole evolution of a cavitation bubble, including its growth, collapse and rebound near a rigid wall. Single-phase Navier-Stokes equation in the liquid region is solved by MAC projection algorithm combined with second-order ENO scheme for the advection terms. The moving inter-face is captured by the level set function, and the interface velocity is resolved by ＂one-side＂ velocity extension from the liquid region to the bubble region, complementing the second-order weighted least squares method across the interface and projection inside bubble. The use of non-uniform grid overcomes the difficulty caused by the large computational domain and very small bubble size. The computation is very stable without suffering from large flow-field gradients, and the results are in good agreements with other studies. The bubble interface kinematics, dynamics and its effect on the wall are highlighted, which shows that the code can effectively capture the ＂shock wave＂-like pressure and velocity at jet impact, toroidal bubble, and complicated pressure structure with peak, plateau and valley in the later stage of bubble oscillating.展开更多
Urmia Lake in northwest of Iran, through the recent years has been extremely faced with the water crisis. Climate variations and anthropogenic impacts could be two main affiliated factors in this regard. We considered...Urmia Lake in northwest of Iran, through the recent years has been extremely faced with the water crisis. Climate variations and anthropogenic impacts could be two main affiliated factors in this regard. We considered the long term data series of precipitation, temperature and evaporation in monthly and yearly scales in order to compare to water-level values of Urmia Lake. The statistics approaches such as: standard deviation, trend analysis, T test, Pearson and Spearman correlations, liner regression are used to analyze all variables. The results released that the water-level of Urmia Lake along with the precipitation and temperature of the lake’s basin have experienced the periodic changes through 1961 to 2010, as there are some gradual dryness trends on the study area according to precipitation and temperature variations. Urmia Lake periodic water-level fluctuations show more significant correlation to temperature than the precipitation. Whiles, the water-level’s decreasing behavior especially through 1998 to 2010 is more harsh and different than the rate that is considered for precipitation’s decrease and temperature’s increase. Thus, there could be some anthropogenic factors in the basin which produced some supplementary causes to shrink Urmia Lake. Extracting the double precipitation over the basin through introducing and categorizing of atmospheric synoptic systems in order to cloud seeding operation could be one of urgent and innovative solutions to mitigate water crisis in the basin.展开更多
Sea level rise (SLR) could critically endanger the environment along all the world’s sea coasts. Although sudden SLRs of meters-high waves that might have apocalyptic results would generally be limited to specific ar...Sea level rise (SLR) could critically endanger the environment along all the world’s sea coasts. Although sudden SLRs of meters-high waves that might have apocalyptic results would generally be limited to specific areas, on-going SLR of dozens of cms over decades is likely to have adverse impact on coastal environments throughout the world. This study’s objective is to assess relative regional vulnerability of global sea coasts to SLR. The study focuses upon key natural and anthropogenic parameters that might either cause or enhance SLR and thus significantly influence regional coastal environments. Careful assessment can enable reasonable estimates of relative vulnerability of such environments. An initial step involves specifying key parameters and assigning their weightings and ratings. To demonstrate the feasibility of this approach, six seacoast regions from various parts of the world have been considered in this paper, assessing their natural and anthropogenic parameters vis-à-vis general global data. The results emphasize the relative vulnerability of these areas’ environments to SLR. Recommendations are then made for improving global SLR modeling and monitoring.展开更多
文摘With regard to brain acetylcholinesterase and acetylcholine and serum triiodothyronine(T_3) and thyroxine(T_4)profiles,a biphasic response pattern was elicited in Channa punctatus chroni- cally exposed to nonlethal doses of locally used pesticides,namely,Metacid-50 and Carbaryl. Data revealed that these xenobiotics caused significant inhibition of brain acetylcholinesterase activity and a decrease in thyroxine level accompanied by a concurrent increase in acetylcholine accumulation and T_3 level.It is surmised that Metacid-50 and Carbaryl influence both neural and hormonal functions.1989 Academic Press.Inc.
文摘One of the significant consequences of the climate change predicted for the next decades is the sea and ocean level rise.The coastal zone of Mohammedia (Morocco),a site of significant socio-economic activeties largely open to the Atlantic Ocean,is thus confronted with hydrodynamic agents and a possible sea level rise,whose impacts will result in an immersion of the low topography areas。
文摘The study focused on the impacts of climate change on the farmer and the farming families in Niger Delta Region of Nigeria. The study specifically evaluated the perceived resultant situations attributed to climate change to determine the extent of impacts of climate change on the farmer and the farming families and also explored adoptable strategies for coping with the situations. The study adopted descriptive survey research design. Two research questions and two hypotheses guided the study. The population for the study was 246,909 respondents made up of farmers and extension workers who are registered with the State Ministries of Agriculture. Out of the nine Niger Delta states, Bayelsa and Delta states were randomly chosen for the study. Proportionate stratified random sampling technique was used to select a sample size of 5,038 respondents. Structured questionnaire and interview were used to collect data. The instruments were validated by three experts. Cronbach Alpha method was used to determine the internal consistency of the questionnaire items which yielded a coefficient of 0.81. The Statistical Product and Service Solutions (SPSS v 20.0) was employed for data analysis. The statistical tools used for data analysis were weighted mean to answer research questions and standard deviation to validate the closeness of the respondents from the mean and from each other in their responses while t-test was used to test the null hypotheses. The findings of the study revealed that the extent of impacts of climate change on farmers and the farming families in Niger Delta region of Nigeria are moderate. Findings further revealed that climate change has led to increased poverty level and raised cost of production (input and labour cost) as indicated by the farmers. The study recommends that farmers in the region should be encouraged by providing incentives and subsidizing inputs for them by Federal and State governments as well as other non-governmental organizations, as this will go a long way in improving production especially as most farmers agree to continue cultivation even with the observed impacts.
文摘Purpose: This paper describes an alternative way of assessing journals considering a broader perspective of its impact. The Area-based connectedness(ABC) to society of journals applied here contributes to the assessment of the dissemination task of journals but with more data it may also contribute to the assessment of other missions.Design/methodology/approach: The ABC approach assesses the performance of research actors, in this case journals, considering the characteristics of the research areas in which they are active. Each paper in a journal inherits the characteristics of its area. These areas are defined by a publication-based classification. The characteristics of areas relate to 5 dimensions of connectedness to society(news, policy, industrial R&D, technology and local interest) and are calculated by bibliometric indicators and social media metrics. Findings: In the paper, I illustrate the approach by showing the results for a few journals. They illustrate the diverse profiles that journals may have. We are able to provide a profile for each journal in the Web of Science database. The profiles we present show an appropriate view on the journals’ societal connectedness.Research limitations: The classification I apply to perform the analyses is a CWTS in house classification based on Web of Science data. As such the application depends on the(updates of) that system. The classification is available at www.leidenranking.com.Practical implications: The dimensions of connectedness discussed in this paper relate to the dissemination task of journals but further development of this method may provide more options to monitor the tasks/mission of journals. Originality/value: The ABC approach is a unique way to assess performance or impact of research actors considering the characteristics of the areas in which output is published and as such less prone to manipulation or gaming.
基金supported by the National Basic Research Program of China(2010CB951303)the Special Fund for Agro-Scientific Research in the Public Interest(200903003)the Basic Operation Cost of China Meteorological Administration(CMA)
文摘The impacts of climate change on rice yield in China from 1961 to 2010 were studied in this paper, based on the provincial data, in order to develop scientiifc countermeasures. The results indicated that increase of average temperature improved single cropping rice production on national level by up to 11%relative to the average over the study period, however, it resulted in an overall loss of double cropping rice by up to 1.9%. The decrease of diurnal temperature range （DTR） in the major producing regions caused the decrease by up to 3.0%for single cropping rice production and 2.0%for double cropping rice production. Moreover, the contribution of precipitation change reached about 6.2%for single cropping rice production, but no signiifcant effect for double cropping rice production in recent 50 years.
基金Project supported by the National Natural Science Foundation of China(Nos.11672310 and 11372326)the National Basic Research Program of China(No.2014CB04680202)
文摘A splashing crown is commonly observed when a high-speed drop impacts a liquid film. The influence of the liquid viscosity on the crown＇s evolution is not yet clear. We review several existing theories of this problem, and carry out a series of numerical simulations. We find that a three-segment model can describe the crown＇s motion. In the very early stage when the crown is barely visible, the influence of viscosity is small. Later, a shallow water approach used in most existing models is applicable as long as the initial conditions are formulated properly. They depend on viscous dissipation in the intermediate period. Preliminary estimation based on a dissipation function is proposed to characterize the influence of viscosity in this problem.
文摘One of the clear signals of the ongoing climate change is sea level rise (SLR). Normal oceanic tides superimposed on a rising sea level and coastal flooding will affect many coastal communities. An international collaboration among Brazil, the United Kingdom, and the United States was designed to evaluate local decision making processes and to open space for local urban managers to reflect on possible actions toward adaption to sea level rise given the historical constraints imposed by administrative and institutional structures. This project focused on the processes that shape adaptation of three coastal communities in three countries. It worked jointly with these communities in defining the problem, examining risks, and understanding the benefits and obstacles that may hinder implementation of adaptation options. The framework was co-designed by an interdisciplinary team that incorporated social and natural scientists from the three countries, including local government officials. The study addressed 1) evaluation of adaptive capacity through participant surveys and 2) physical and cost impact simulations using geospatial models of the built infrastructure and implementation of adaptation options under different hazard scenarios, including 50 and 100-year sea level rise projections and severe storms. Based on the surveys’ results, there is a clear sense of the awareness of each community of the risk of floods due to intense storms, and of the usefulness of engaging early in a process that promotes the understanding of risks, impacts, and costs. A majority of workshop participants prioritized pursuing physical and green infrastructure actions now or within coming years or decades. A positive common aspect of the three sites was the commitment shown by the stakeholders in taking part in the process and evaluating which adaptation measures could be more effective in their cities. While in the US and UK structural solutions and voluntary buyouts were prioritized for the future, Brazil prioritized structural solutions and ecosystems restoration and not voluntary buyouts. All of these are choices to increase resiliency against sea level rise that have a high benefit-cost ratio. The Adaptive Capacity Index (ACI) results illustrate barriers to adaptation action, including technical, economic and political issues that reveal inequalities in adaptive capacity among case studies.
基金the National Natural Science Foundation of China(10272032 and 10672043).
文摘A level set method of non-uniform grids is used to simulate the whole evolution of a cavitation bubble, including its growth, collapse and rebound near a rigid wall. Single-phase Navier-Stokes equation in the liquid region is solved by MAC projection algorithm combined with second-order ENO scheme for the advection terms. The moving inter-face is captured by the level set function, and the interface velocity is resolved by ＂one-side＂ velocity extension from the liquid region to the bubble region, complementing the second-order weighted least squares method across the interface and projection inside bubble. The use of non-uniform grid overcomes the difficulty caused by the large computational domain and very small bubble size. The computation is very stable without suffering from large flow-field gradients, and the results are in good agreements with other studies. The bubble interface kinematics, dynamics and its effect on the wall are highlighted, which shows that the code can effectively capture the ＂shock wave＂-like pressure and velocity at jet impact, toroidal bubble, and complicated pressure structure with peak, plateau and valley in the later stage of bubble oscillating.
文摘Urmia Lake in northwest of Iran, through the recent years has been extremely faced with the water crisis. Climate variations and anthropogenic impacts could be two main affiliated factors in this regard. We considered the long term data series of precipitation, temperature and evaporation in monthly and yearly scales in order to compare to water-level values of Urmia Lake. The statistics approaches such as: standard deviation, trend analysis, T test, Pearson and Spearman correlations, liner regression are used to analyze all variables. The results released that the water-level of Urmia Lake along with the precipitation and temperature of the lake’s basin have experienced the periodic changes through 1961 to 2010, as there are some gradual dryness trends on the study area according to precipitation and temperature variations. Urmia Lake periodic water-level fluctuations show more significant correlation to temperature than the precipitation. Whiles, the water-level’s decreasing behavior especially through 1998 to 2010 is more harsh and different than the rate that is considered for precipitation’s decrease and temperature’s increase. Thus, there could be some anthropogenic factors in the basin which produced some supplementary causes to shrink Urmia Lake. Extracting the double precipitation over the basin through introducing and categorizing of atmospheric synoptic systems in order to cloud seeding operation could be one of urgent and innovative solutions to mitigate water crisis in the basin.
文摘Sea level rise (SLR) could critically endanger the environment along all the world’s sea coasts. Although sudden SLRs of meters-high waves that might have apocalyptic results would generally be limited to specific areas, on-going SLR of dozens of cms over decades is likely to have adverse impact on coastal environments throughout the world. This study’s objective is to assess relative regional vulnerability of global sea coasts to SLR. The study focuses upon key natural and anthropogenic parameters that might either cause or enhance SLR and thus significantly influence regional coastal environments. Careful assessment can enable reasonable estimates of relative vulnerability of such environments. An initial step involves specifying key parameters and assigning their weightings and ratings. To demonstrate the feasibility of this approach, six seacoast regions from various parts of the world have been considered in this paper, assessing their natural and anthropogenic parameters vis-à-vis general global data. The results emphasize the relative vulnerability of these areas’ environments to SLR. Recommendations are then made for improving global SLR modeling and monitoring.
