An experiment was conducted in mango orchard of Sher-E Bangla Agricultural University (SAU) campus, Dhaka to determine the effect of seasonal variation round the year and weather on population dynamics of mango mealyb...An experiment was conducted in mango orchard of Sher-E Bangla Agricultural University (SAU) campus, Dhaka to determine the effect of seasonal variation round the year and weather on population dynamics of mango mealybug (Drosicha mangiferae) on mango tree. The mango mealybug was first appeared in early December and disappeared in June in a year. Its population started to increase gradually from December and continued up to February when the ambient average temperature was 20.95°C, relative humidity 63% and rainfall was absent. The highest population of the insect (33.33/30 cm branch) was recorded in February and the lowest (3.75/30cm branch) in May. Adult insects appeared in February on the ground under the selected mango tree showing the population of 6.67 males and 123.33 females per 81 m<sup>2</sup>. Population of males (32.5/81m<sup>2</sup>) and that of females (352.75/81m<sup>2</sup>) reached to the peak when the ambient temperature was 28.19°C, relative humidity 61% and the rainfall was 0.00 mm. When relative humidity was high and rainfall started adult females enter into the soil and disappeared. Correlation between population of mealybug and temperature was positive. Its population was negatively correlated with relative humidity and rainfall.展开更多
In glacierized catchments, glacier runoff typically shows a strong diurnal cycle in the ablation season(June-September). To elucidate the effect of these processes on the chemical weathering, fresh snowfall and water ...In glacierized catchments, glacier runoff typically shows a strong diurnal cycle in the ablation season(June-September). To elucidate the effect of these processes on the chemical weathering, fresh snowfall and water samples were collected and studied from the supraglacial river, proglacial river,and gauging site in Qiyi glacierized catchment Qilian Mountains, Northwestern China, in the summer of2011. The pH and electronic conductivity(EC) were determined in the field, and the concentrations of major ions(Na^+, K^+, Mg^(2+), Ca^(2+), Cl^-, SO_4^(2-), NO_3^-) were measured. The results indicated that EC linearly increased with increasing distance from the glacial snout, and the concentrations of major ions increased with increasing water-rock interaction time. Along the flow path of the glacier runoff, Na^+ and Cl^-are more concentrated than other ions in the supraglacial river while Mg^(2+) and SO_4^(2-)are more concentrated than other ions at the gauging site. The discharge, pH, EC,and the concentrations of major ions exhibited significant diurnal variation along the flow path. On the other hand, the amplitude of variation diminished from upstream to downstream along the flow path.The chemical weathering rate(Na^++K^++Mg^(2+)+Ca^(2+))was determined to be 10.9 t/yr/km^2. Moreover,further research indicated that the sampling method influenced the assessment of chemical weathering rates. When the sample was collected randomly in one diurnal cycle of hydrography, the estimated ionic flux could deviate-47%~73% based on estimated hourly data. In contrast, if three samples were collected at peak, base flow and the discharge decreasing rate starts to slow down in one diurnal cycle of hydrography, respectively, the deviation would be less than 15%. The smaller the diurnal variation of discharge, the smaller deviation calculated.展开更多
[Objective] The research aimed to study the variation characteristics of low temperature and rainy weather in Guangxi during spring sowing period of recent 50 years.[Method] Based on the daily average temperature data...[Objective] The research aimed to study the variation characteristics of low temperature and rainy weather in Guangxi during spring sowing period of recent 50 years.[Method] Based on the daily average temperature data from 1961 to 2010 at 88 meteorological stations in Guangxi,yearly days and end date of low temperature and rainy weather during spring sowing period were carried out statistics.The variation characteristics of low temperature and rainy weather in Guangxi during spring sowing period of recent 50 years were analyzed by using linear tendency calculation,phased analysis,Morlet wavelet analysis and correlation analysis.Moreover,the influences of climate warming on days and end date of low temperature and rainy weather in spring sowing period were analyzed.[Result] The average days of low temperature and rainy weather in Guangxi during spring sowing period from 1961 to 2010 was during 3.5-23.2 d.The regional distribution characteristics were that it was more in northeast and mountain zone,and less in southwest and valley.The regional distribution characteristics of end date were that it was late in northeast and mountain zone,and early in southwest and valley.The days of low temperature and rainy weather in Guangxi during spring sowing period of recent 50 years presented slight decrease trend,and the end date presented slight advancing trend.The phased variation characteristics of days and end date of low temperature and rainy weather were obvious.The days of low temperature and rainy weather from the early 1980s to metaphase of 1990s was obviously more,and the end date was obviously later.After the 1990s,the days of low temperature and rainy weather was obviously less,and the end date was obviously earlier.The days of low temperature and rainy weather had periodic oscillation signals of 4,6,8,10-14 years.The end date had periodic oscillation signals of 6,12-14 years.The days and end date of low temperature and rainy weather in Guangxi during spring sowing period significantly related to average temperature from middle dekad of February to first dekad of April.The climate warming made that the days of low temperature and rainy weather tended to decrease,and the end date tended to advance.[Conclusion] The research provided reference for further understanding the occurrence rule of low temperature and rainy weather,going after profits and avoiding disadvantages,reasonably arranging production,carrying out correlated research.展开更多
Interaction between prey and predator species is a complex and non-linear process. Understanding various phenomena in the dynamics of prey-predator systems is vital to both mathematical ecology and conservation biolog...Interaction between prey and predator species is a complex and non-linear process. Understanding various phenomena in the dynamics of prey-predator systems is vital to both mathematical ecology and conservation biology. Mathematical models on prey-predator systems have been the hot sport providing important information regarding the interactions of prey and predator species in various ecosystems. In this paper, a review of the available mathematical models on prey-predator systems was done. Our aim was to assess their structure, behaviour, available control strategies, population involved and their ability in predicting the future behaviour of the ecosystems. We observed diversities in the reviewed mathematical models, some model incorporated factors such as drought, harvesting and prey refuge as the factors that affect ecosystems, some ignored the contribution of environmental variations while others considered the variable carrying capacity. Most of the models reviewed have not considered the contribution of diseases and seasonal weather variation in the dynamics of prey predator systems. Some of the reviewed models do not match the real situation in most modelled ecosystems. Thus, to avoid unreliable results, this review reveals the need to incorporate seasonal weather variations and diseases in the dynamics of prey predator systems of Serengeti ecosystem.展开更多
In this paper, we use a spectral model for the medium-range numerical weather forecast to discuss the impact of the diurnal variation of solar radiation on the medium-range weather processes. Under the tests of two ty...In this paper, we use a spectral model for the medium-range numerical weather forecast to discuss the impact of the diurnal variation of solar radiation on the medium-range weather processes. Under the tests of two typical winter and summer cases, we find that the influences of the diurnal variation of solar radiation on summer weather are really important, especially on its rainfall, surface heat transport and 500 hPa height field. On winter weather, however, the influences are very weak.展开更多
The recent progresses in the research and development of (NWP) in China are reviewed in this paper. The most impressive achievements are the development of direct assimilation of satellite irradiances with a 3DVAR (th...The recent progresses in the research and development of (NWP) in China are reviewed in this paper. The most impressive achievements are the development of direct assimilation of satellite irradiances with a 3DVAR (three-dimentional variational) data assimilation system and a non-hydrostatic modei with a semi-Lagrangian semi-implicit scheme. Progresses have also been made in modei physics and modei application to precipitation and environmental forecasts. Some scientific issues of great importance for further development are discussed.展开更多
More than million people die from malaria every year(Philippe Brasseur et al.,1999).Some studies indicate that there may be as many as 3 million deaths and above per year due to malaria.Up to 90%of which occur in Afri...More than million people die from malaria every year(Philippe Brasseur et al.,1999).Some studies indicate that there may be as many as 3 million deaths and above per year due to malaria.Up to 90%of which occur in Africa,and 90%are children under age of 5 years.WHO estimates that 40%of the World’s population is at risk of malaria(Victor Ojeanelo, 2007).Weather and climate have significant effects on the growth and distribution of malaria transmitting mosquitos.Rainfall and temperature limits the growth and development of Anopheles mosquito,which展开更多
Objective:To investigate the effect of cold weather on carotid artery stenosis and occlusion.Methods:We conducted a retrospective observational study,in which 145 patients with carotid artery stenosis and occlusion we...Objective:To investigate the effect of cold weather on carotid artery stenosis and occlusion.Methods:We conducted a retrospective observational study,in which 145 patients with carotid artery stenosis and occlusion were enrolled[115 men and 30 women;the mean age was 61.08 years(95%CI 59.27-62.88)].Patients were divided into the low-temperature group(n=98)(≤12℃)and the non-low temperature group(n=47)(>12℃).Clinical characteristics,blood pressure,National Institutes of Health Stroke Scale(NIHSS),blood fat,and blood viscositys were compared between the two groups.Correlation between NIHSS and mean daily temperature was analyzed.Results:There was no significant difference in the systolic and diastolic blood pressure between the two groups(P>0.05).The NIHSS score was slightly higher in the non-low temperature group compared to that of the low-temperature group(U=2984,P<0.01).Glycemia,cholesterol level,prothrombin time,fibrinogen,and International Normalized Ratio did not show any significant difference(P>0.05).Correlation analysis showed a very low positive and statistically significant correlation between ambient temperature and NIHSS score(r=0.18,P=0.029).Conclusion:Cold weather does not impact blood pressure,blood cholesterol,and coagulation factors of patients with carotid artery stenosis and occlusion.The neurological deficit is more severe in the non-low ambient temperature group.A potential relationship exists between ambient temperature and the level of neurological impairment.展开更多
文摘An experiment was conducted in mango orchard of Sher-E Bangla Agricultural University (SAU) campus, Dhaka to determine the effect of seasonal variation round the year and weather on population dynamics of mango mealybug (Drosicha mangiferae) on mango tree. The mango mealybug was first appeared in early December and disappeared in June in a year. Its population started to increase gradually from December and continued up to February when the ambient average temperature was 20.95°C, relative humidity 63% and rainfall was absent. The highest population of the insect (33.33/30 cm branch) was recorded in February and the lowest (3.75/30cm branch) in May. Adult insects appeared in February on the ground under the selected mango tree showing the population of 6.67 males and 123.33 females per 81 m<sup>2</sup>. Population of males (32.5/81m<sup>2</sup>) and that of females (352.75/81m<sup>2</sup>) reached to the peak when the ambient temperature was 28.19°C, relative humidity 61% and the rainfall was 0.00 mm. When relative humidity was high and rainfall started adult females enter into the soil and disappeared. Correlation between population of mealybug and temperature was positive. Its population was negatively correlated with relative humidity and rainfall.
基金supported by theNatural Science Foundation of China(Grant Nos.41471057,41571076,41201063)
文摘In glacierized catchments, glacier runoff typically shows a strong diurnal cycle in the ablation season(June-September). To elucidate the effect of these processes on the chemical weathering, fresh snowfall and water samples were collected and studied from the supraglacial river, proglacial river,and gauging site in Qiyi glacierized catchment Qilian Mountains, Northwestern China, in the summer of2011. The pH and electronic conductivity(EC) were determined in the field, and the concentrations of major ions(Na^+, K^+, Mg^(2+), Ca^(2+), Cl^-, SO_4^(2-), NO_3^-) were measured. The results indicated that EC linearly increased with increasing distance from the glacial snout, and the concentrations of major ions increased with increasing water-rock interaction time. Along the flow path of the glacier runoff, Na^+ and Cl^-are more concentrated than other ions in the supraglacial river while Mg^(2+) and SO_4^(2-)are more concentrated than other ions at the gauging site. The discharge, pH, EC,and the concentrations of major ions exhibited significant diurnal variation along the flow path. On the other hand, the amplitude of variation diminished from upstream to downstream along the flow path.The chemical weathering rate(Na^++K^++Mg^(2+)+Ca^(2+))was determined to be 10.9 t/yr/km^2. Moreover,further research indicated that the sampling method influenced the assessment of chemical weathering rates. When the sample was collected randomly in one diurnal cycle of hydrography, the estimated ionic flux could deviate-47%~73% based on estimated hourly data. In contrast, if three samples were collected at peak, base flow and the discharge decreasing rate starts to slow down in one diurnal cycle of hydrography, respectively, the deviation would be less than 15%. The smaller the diurnal variation of discharge, the smaller deviation calculated.
基金Supported by Special Item of Climate Variation of China Meteorologcal Administration (CCSF2011-25)Guangxi Science Foundation Item (Guiqingke 0991060)
文摘[Objective] The research aimed to study the variation characteristics of low temperature and rainy weather in Guangxi during spring sowing period of recent 50 years.[Method] Based on the daily average temperature data from 1961 to 2010 at 88 meteorological stations in Guangxi,yearly days and end date of low temperature and rainy weather during spring sowing period were carried out statistics.The variation characteristics of low temperature and rainy weather in Guangxi during spring sowing period of recent 50 years were analyzed by using linear tendency calculation,phased analysis,Morlet wavelet analysis and correlation analysis.Moreover,the influences of climate warming on days and end date of low temperature and rainy weather in spring sowing period were analyzed.[Result] The average days of low temperature and rainy weather in Guangxi during spring sowing period from 1961 to 2010 was during 3.5-23.2 d.The regional distribution characteristics were that it was more in northeast and mountain zone,and less in southwest and valley.The regional distribution characteristics of end date were that it was late in northeast and mountain zone,and early in southwest and valley.The days of low temperature and rainy weather in Guangxi during spring sowing period of recent 50 years presented slight decrease trend,and the end date presented slight advancing trend.The phased variation characteristics of days and end date of low temperature and rainy weather were obvious.The days of low temperature and rainy weather from the early 1980s to metaphase of 1990s was obviously more,and the end date was obviously later.After the 1990s,the days of low temperature and rainy weather was obviously less,and the end date was obviously earlier.The days of low temperature and rainy weather had periodic oscillation signals of 4,6,8,10-14 years.The end date had periodic oscillation signals of 6,12-14 years.The days and end date of low temperature and rainy weather in Guangxi during spring sowing period significantly related to average temperature from middle dekad of February to first dekad of April.The climate warming made that the days of low temperature and rainy weather tended to decrease,and the end date tended to advance.[Conclusion] The research provided reference for further understanding the occurrence rule of low temperature and rainy weather,going after profits and avoiding disadvantages,reasonably arranging production,carrying out correlated research.
文摘Interaction between prey and predator species is a complex and non-linear process. Understanding various phenomena in the dynamics of prey-predator systems is vital to both mathematical ecology and conservation biology. Mathematical models on prey-predator systems have been the hot sport providing important information regarding the interactions of prey and predator species in various ecosystems. In this paper, a review of the available mathematical models on prey-predator systems was done. Our aim was to assess their structure, behaviour, available control strategies, population involved and their ability in predicting the future behaviour of the ecosystems. We observed diversities in the reviewed mathematical models, some model incorporated factors such as drought, harvesting and prey refuge as the factors that affect ecosystems, some ignored the contribution of environmental variations while others considered the variable carrying capacity. Most of the models reviewed have not considered the contribution of diseases and seasonal weather variation in the dynamics of prey predator systems. Some of the reviewed models do not match the real situation in most modelled ecosystems. Thus, to avoid unreliable results, this review reveals the need to incorporate seasonal weather variations and diseases in the dynamics of prey predator systems of Serengeti ecosystem.
文摘In this paper, we use a spectral model for the medium-range numerical weather forecast to discuss the impact of the diurnal variation of solar radiation on the medium-range weather processes. Under the tests of two typical winter and summer cases, we find that the influences of the diurnal variation of solar radiation on summer weather are really important, especially on its rainfall, surface heat transport and 500 hPa height field. On winter weather, however, the influences are very weak.
文摘The recent progresses in the research and development of (NWP) in China are reviewed in this paper. The most impressive achievements are the development of direct assimilation of satellite irradiances with a 3DVAR (three-dimentional variational) data assimilation system and a non-hydrostatic modei with a semi-Lagrangian semi-implicit scheme. Progresses have also been made in modei physics and modei application to precipitation and environmental forecasts. Some scientific issues of great importance for further development are discussed.
文摘More than million people die from malaria every year(Philippe Brasseur et al.,1999).Some studies indicate that there may be as many as 3 million deaths and above per year due to malaria.Up to 90%of which occur in Africa,and 90%are children under age of 5 years.WHO estimates that 40%of the World’s population is at risk of malaria(Victor Ojeanelo, 2007).Weather and climate have significant effects on the growth and distribution of malaria transmitting mosquitos.Rainfall and temperature limits the growth and development of Anopheles mosquito,which
文摘Objective:To investigate the effect of cold weather on carotid artery stenosis and occlusion.Methods:We conducted a retrospective observational study,in which 145 patients with carotid artery stenosis and occlusion were enrolled[115 men and 30 women;the mean age was 61.08 years(95%CI 59.27-62.88)].Patients were divided into the low-temperature group(n=98)(≤12℃)and the non-low temperature group(n=47)(>12℃).Clinical characteristics,blood pressure,National Institutes of Health Stroke Scale(NIHSS),blood fat,and blood viscositys were compared between the two groups.Correlation between NIHSS and mean daily temperature was analyzed.Results:There was no significant difference in the systolic and diastolic blood pressure between the two groups(P>0.05).The NIHSS score was slightly higher in the non-low temperature group compared to that of the low-temperature group(U=2984,P<0.01).Glycemia,cholesterol level,prothrombin time,fibrinogen,and International Normalized Ratio did not show any significant difference(P>0.05).Correlation analysis showed a very low positive and statistically significant correlation between ambient temperature and NIHSS score(r=0.18,P=0.029).Conclusion:Cold weather does not impact blood pressure,blood cholesterol,and coagulation factors of patients with carotid artery stenosis and occlusion.The neurological deficit is more severe in the non-low ambient temperature group.A potential relationship exists between ambient temperature and the level of neurological impairment.
