Pseudotsuga forrestii is a relict evergreen coniferous tree species in Pinaceae endemic to China.P.forrestii tree numbers have greatly decreased due to deforestation,over-utilization and habitat degradation.Here we cl...Pseudotsuga forrestii is a relict evergreen coniferous tree species in Pinaceae endemic to China.P.forrestii tree numbers have greatly decreased due to deforestation,over-utilization and habitat degradation.Here we clarify P.forrestii community types,structure,species diversity,seedling recruitments and growth trends.We identified four P.forrestii community types:(1)Pseudotsuga forrestii-Quercus guyavifolia-Acer davidii evergreen coniferous and broad-leaved mixed forest;(2)Pseudotsuga forrestii-Pinus yunnanensis-Quercus guyavifolia evergreen coniferous and broad-leaved mixed forest;(3)Pseudotsuga forrestii evergreen coniferous forest;(4)Pseudotsuga forrestii-Abies georgei var.smithii evergreen coniferous forest.P.forrestii forests are characterized by both warm temperate and temperate affinities.Simpson diversity,Pielou evenness,Shannon-Wiener diversity indices ranged from 0.75 to 0.76,0.74-0.81,and 1.62-1.93,respectively,with no significant differences among the four forest types.The forest stratification was multilayered.The canopy layer was generally 10-25 m tall,with the emergent layer reached 25-42 m.DBH and age structures of P.forrestii showed multimodal distributions.Its maximum age P.forrestii was 570 years with a DBH of 143 cm.The growth of annual ring width of P.forrestii was slow,and generally decreased with age,whereas the basal area at the breast height increased with age.Established seedlings/saplings were mainly found in unstable micro-habitats.Regeneration of P.forrestii depends on moderate natural disturbances.Finally,we provide recommendations for P.forrestii conservation.展开更多
Background: China is one of the countries with abundant waterbird diversity. Over the past decades, China's waterbirds have suffered increasing threats from direct and indirect human activities. It is important to...Background: China is one of the countries with abundant waterbird diversity. Over the past decades, China's waterbirds have suffered increasing threats from direct and indirect human activities. It is important to clarify the population trends of and threats to waterbirds as well as to put forward conservation recommendations.Methods: We collected data of population trends of a total of 260 waterbird species in China from Wetlands International database. We calculated the number of species with increasing, declining, stable, and unknown trends. We collected threatened levels of waterbirds from the Red List of China's Vertebrates(2016), which was compiled according to the IUCN criteria of threatened species. Based on literature review, we refined the major threats to the threatened waterbird species in China.Results: Of the total 260 waterbird species in China, 84 species(32.3%) exhibited declining, 35 species(13.5%) kept stable, and 16 species(6.2%) showed increasing trends. Population trends were unknown for 125 species(48.1%). There was no significant difference in population trends between the migratory(32.4% decline) and resident(31.8% decline) species or among waterbirds distributed exclusively along coasts(28.6% decline), inland(36.6% decline), and both coasts and inland(32.5% decline). A total of 38 species(15.1% of the total) were listed as threatened species and 27 species(10.8% of the total) Near Threatened species. Habitat loss was the major threat to waterbirds, with 32 of the total 38(84.2%) threatened species being affected. In addition, 73.7%(28 species), 71.1%(27 species), and 57.9%(22 species) of the threatened species were affected by human disturbance, environmental pollution, and illegal hunting, respectively.Conclusions: We propose recommendations for waterbird conservation, including(1) strengthening conservation of nature wetlands and restoration of degraded wetlands,(2) enhancing public awareness on waterbird conservation,(3) improving the enforcement of Wildlife Protection Law and cracking down on illegal hunting,(4) carrying out longterm waterbird surveys to clarify population dynamics,(5) restoring populations of highly-threatened species through artificial intervention, and(6) promoting international and regional exchanges and cooperation to share information in waterbirds and their conservation.展开更多
The Great Bustard(Otis tarda) world population is estimated to be 44100–57000 individuals in 2010,of which about 57–70% occur in Spain,15–25% in European Russia,4–10% in China,Mongolia and south-eastern Russia,3–...The Great Bustard(Otis tarda) world population is estimated to be 44100–57000 individuals in 2010,of which about 57–70% occur in Spain,15–25% in European Russia,4–10% in China,Mongolia and south-eastern Russia,3–4% in Portugal,3% in Hungary,1–2% in Turkey,and smaller numbers in ten other countries.The reliability of current censuses and estimates may be described as high for a large fraction of the world population(67–75%),and low for the remain-ing 25–33%(including Russia,Mongolia,China,Turkey,Ukraine,Iran and Kazakhstan).In spite of continued declines reported for some countries(e.g.,Turkey,Iran,China) ,the present survey suggests that total numbers have not significantly decreased worldwide during the last decade,as opposed to the globally declining trend currently assumed.This is due to a large fraction of the world total living in countries whose overall surveys are apparently stable(e.g.,Spain,Portugal),after a noticeable recovery during the last few decades once the hunting ban was established.Only 6–10% of the world total is apparently still decreasing,mostly due to agricultural intensification,other causes of habitat degradation,and locally,also illegal hunting and collision with power lines.A small fraction of the world population(3–4%),is clearly(Germany,Austria) or apparently(Hungary) increasing,due to management and conservation measures.Finally,19–22% of the world total has an uncertain status,due to inaccurate current or past censuses which prevent establishing reliable population trends.We recommend 1)keeping conservation efforts and the species’protection status worldwide,and 2)carrying out urgently nation-wide surveys in countries with low quality estimates,in order to confirm world numbers and trends.展开更多
The characteristics of drought in Xinjiang Uygur Autonomous Region(Xinjiang),China have changed due to changes in the spatiotemporal patterns of temperature and precipitation,however,the effects of temperature and pre...The characteristics of drought in Xinjiang Uygur Autonomous Region(Xinjiang),China have changed due to changes in the spatiotemporal patterns of temperature and precipitation,however,the effects of temperature and precipitation—the two most important factors influencing drought—have not yet been thoroughly explored in this region.In this study,we first calculated the standard precipitation evapotranspiration index(SPEI)in Xinjiang from 1980 to 2020 based on the monthly precipitation and monthly average temperature.Then the spatiotemporal characteristics of temperature,precipitation,and drought in Xinjiang from 1980 to 2020 were analyzed using the Theil-Sen median trend analysis method and Mann-Kendall test.A series of SPEI-based scenario-setting experiments by combining the observed and detrended climatic factors were utilized to quantify the effects of individual climatic factor(i.e.,temperature and precipitation).The results revealed that both temperature and precipitation had experienced increasing trends at most meteorological stations in Xinjiang from 1980 to 2020,especially the spring temperature and winter precipitation.Due to the influence of temperature,trends of intensifying drought have been observed at spring,summer,autumn,and annual scales.In addition,the drought trends in southern Xinjiang were more notable than those in northern Xinjiang.From 1980 to 2020,temperature trends exacerbated drought trends,but precipitation trends alleviated drought trends in Xinjiang.Most meteorological stations in Xinjiang exhibited temperature-dominated drought trend except in winter;in winter,most stations exhibited precipitation-dominated wetting trend.The findings of this study highlight the importance of the impact of temperature on drought in Xinjiang and deepen the understanding of the factors influencing drought.展开更多
In this work,we report long-term trends in the abundance and breeding performance of Adélie penguins(Pygoscelis adeliae)nesting in three Antarctic colonies(i.e.,at Martin Point,South Orkneys Islands;Stranger Poin...In this work,we report long-term trends in the abundance and breeding performance of Adélie penguins(Pygoscelis adeliae)nesting in three Antarctic colonies(i.e.,at Martin Point,South Orkneys Islands;Stranger Point/Cabo Funes,South Shetland Islands;and Esperanza/Hope Bay in the Antarctic Peninsula)from 1995/96 to 2022/23.Using yearly count data of breeding groups selected,we observed a decline in the number of breeding pairs and chicks in crèche at all colonies studied.However,the magnitude of change was higher at Stranger Point than that in the remaining colonies.Moreover,the index of breeding success,which was calculated as the ratio of chicks in crèche to breeding pairs,exhibited no apparent trend throughout the study period.However,it displayed greater variability at Martin Point compared to the other two colonies under investigation.Although the number of chicks in crèche of Adélie penguins showed a declining pattern,the average breeding performance was similar to that reported in gentoo penguin colonies,specifically,those undergoing a population increase(even in sympatric colonies facing similar local conditions).Consequently,it is plausible to assume a reduction of the over-winter survival as a likely cause of the declining trend observed,at least in the Stranger Point and Esperanza colonies.However,we cannot rule out local effects during the breeding season affecting the Adélie population of Martin Point.展开更多
In this special issue of the Journal of Sport and Health Science, analyses of the most recent national prevalence esti- mates from the 2016 Physical Activity and Fimess in China-- The Youth Study （PAFCTYS） are prese...In this special issue of the Journal of Sport and Health Science, analyses of the most recent national prevalence esti- mates from the 2016 Physical Activity and Fimess in China-- The Youth Study （PAFCTYS） are presented. These include the prevalence of moderate-to-vigorous physical activity （MVPA）.展开更多
Data on lion skull measurements taken were collected and analyzed to determine trends in trophy size as an indicator of population size, and area of origin among the concessioned hunting areas in Zambia for the period...Data on lion skull measurements taken were collected and analyzed to determine trends in trophy size as an indicator of population size, and area of origin among the concessioned hunting areas in Zambia for the period 1967-2000. A comparison of trophy quality was also made with Tanzania and Zimbabwe which were the other two key sources of lion trophies in Africa. It was assumed that a comprehensive analysis of lion trophy sizes obtained from trophy hunting would be used as an indicator of hunting pressure on lion populations in Zambia. This approach was used because trophy size is an index of abundance particularly for species such as lion which are difficult to count using conventional census methods. Record lion trophies from Safari Club International rating were also collected and assessed to compare trophy quality obtained from Zambia and those of Tanzania and Zimbabwe for the same period 1967-2000 (33 years). Results obtained suggested that Zambia’s contribution to the record trophies under Safari Club International did not decline in the intervening period 1967-2000 and could not be used as an effective indicator of lion population in Zambia. At regional level, Zambia had second highest 24%, after Tanzania 56%, while Zimbabwe was third, 20%. It was found that the size of skulls could not be used as an effective indicator of population size as the record trophies did not decline while the population was alleged to have declined on the continent. Other factors, such as genetic, low prey densities, snaring, poisoning and problem animal control needed to be investigated to determine their impact on the lion population status.展开更多
AIM To investigate the association between hepatic steatosis and change in left ventricular mass index(LVMI) over five years, and examine whether systolic and diastolic blood pressures are mediators of the association...AIM To investigate the association between hepatic steatosis and change in left ventricular mass index(LVMI) over five years, and examine whether systolic and diastolic blood pressures are mediators of the association between hepatic steatosis and LVMI using a general population sample.METHODS We analyzed data from the Study of Health in Pomerania. The study population comprised 1298individuals aged 45 to 81 years. Hepatic steatosis was defined as the presence of a hyperechogenic pattern of the liver together with elevated serum alanine transferase levels. Left ventricular mass was determined echocardiographically and indexed to height2.7. Path analyses were conducted to differentiate direct and indirect paths from hepatic steatosis to LVMI encompassing systolic and diastolic blood pressure as potential mediating variables.RESULTS Hepatic steatosis was a significant predictor for all measured echocardiographic characteristics at baseline. Path analyses revealed that the association of hepatic steatosis with LVMI change after five years was negligibly small(β =-0.12, s.e. = 0.21, P = 0.55). Systolic blood pressure at baseline was inversely associated with LVMI change(β =-0.09, s.e. = 0.03, P < 0.01), while no association between diastolic blood pressure at baseline and LVMI change was evident(β = 0.03, s.e. = 0.05, P = 0.56). The effect of the indirect path from hepatic steatosis to LVMI via systolic baseline blood pressure was small(β =-0.20, s.e. = 0.10, P = 0.07). No indirect effect was observed for the path via diastolic baseline blood pressure(β = 0.03, s.e. = 0.06, P = 0.60). Similar associations were observed in the subgroup of individuals not receiving beta-blockers, calcium channel blockers, or drugs acting on the reninangiotensin system.CONCLUSION Baseline associations between hepatic steatosis and LVMI do not extend to associations with LVMI change after five years. More studies are needed to study the longitudinal effects of hepatic steatosis on LVMI.展开更多
The population parameters of blood cockles,Tegillarca granosa in the intertidal zone of Marudu Bay,Sabah,Malaysia were investigated based on monthly length-weight frequency data(July 2017 to June 2018).A total of 279 ...The population parameters of blood cockles,Tegillarca granosa in the intertidal zone of Marudu Bay,Sabah,Malaysia were investigated based on monthly length-weight frequency data(July 2017 to June 2018).A total of 279 cockle individuals with shell length and weight ranging from 27.7 mm to 82.2 mm and 13.11 g to 192.7 g were subjected to analysis.T.granosa in Marudu Bay showed a consistent moderately high condition index 4.98±0.86 throughout the year.The exponent b of the length-weight relationship was 2.6 demonstrating negative allometric growth.The estimated asymptotic length(L_(∞)),growth coefficient(K)and growth performance(Ф)of the T.granosa population in Marudu Bay were estimated at 86.68 mm,0.98 a^(-1) and 3.87,respectively.The observed maximum shell length was 82.55 mm and the predicted maximum shell length was 84.44 mm with estimated maximum life span(t_(max))of 3.06 years.The estimated mean lengths at the end of 2,4,6,8,10 and 12 months of age were 21.31 mm,31.16 mm,39.53 mm,46.63 mm,52.67 mm and 57.79 mm.Total,natural,and fishing mortalities were estimated at 2.39 a^(-1),1.32 a^(-1) and 1.07 a^(-1).The exploitation level(E)was 0.45.Results of the current study also demonstrated that T.granosa in the Marudu Bay has two major recruitment peaks;one in March and another in October.The exploitation level revealed that natural stock of T.granosa in the Marudu Bay was approaching the maximum exploitation level.If such trend continues or demand for T.granosa is increasing,coupled with no effective fisheries management in place,possibility of the T.granosa population in the Marudu Bay to collapse is likely to elevate.展开更多
Decelerating open-channel flow is a type of flow that gradually moves forward with decreasing velocity and increasing water depth.Although all flow parameters change along the streamwise direction,previous studies hav...Decelerating open-channel flow is a type of flow that gradually moves forward with decreasing velocity and increasing water depth.Although all flow parameters change along the streamwise direction,previous studies have revealed that these parameters’vertical distributions at different sections can be universally described with a single profile when being nondimensionalised by appropriate scales.This study focuses on the population trends of spanwise rotational motions at various sections along the main flow direction by particle imaging velocimetry(PIV)measurement.The wall-normal population distributions of density,radius,swirling strength,and convection velocity of the prograde and retrograde motions show similar trends in uniform open-channel flows.The dimensionless representation is invariant along the main flow direction.This study’s results indicate the self-similar characteristic of population trends of spanwise rotational motions prevails in decelerating open-channel flow.展开更多
Based on the monthly precipitation data of 116 meteorological stations in Shandong Province during 1970-2021,standardized precipitation index(SPI)was calculated,and the methods of linear fitting,mutation test and Morl...Based on the monthly precipitation data of 116 meteorological stations in Shandong Province during 1970-2021,standardized precipitation index(SPI)was calculated,and the methods of linear fitting,mutation test and Morlet wavelet analysis were used to analyze the change trend and temporal and spatial distribution characteristics of SPI index in the past 52 years.The results show that there were more normal years in Shandong Province,and the frequency reached 38.46%.There was severe drought in the 1980s and more wet years after 2003.SPI index showed an upward trend in spring,summer and winter but a weak arid trend in autumn.In addition,intense dry weather was more frequent in summer.Spatially,the climate was normal or humid in most areas of Shandong Province.The regions with more wet years were located in the central and northeast Shandong and the peninsula,while the climate was normal in the southwest and north of Shandong.The areas with more dry years were mainly located in the northwest of Shandong Province.There was mainly local and global drought in Shandong Province,and the arid area showed a decreasing trend.In the past 52 years,Shandong Province experienced quasi-4 times of alternation between dry and wet climate.The long period of 21 a was the first main period,and the climate would be still wet in Shandong Province in the future.In terms of mutation,the climate in Shandong Province became humid after 2003,and 2003 was the mutation point.After the abrupt change,the climate changed from gradually drying to wetting.展开更多
Even though over many years the IUCN has considered the African buffalo and waterbuck and abundant species in Africa with no conservation concern, the situation is rapidly changing. Using aerial counts in wet and dry ...Even though over many years the IUCN has considered the African buffalo and waterbuck and abundant species in Africa with no conservation concern, the situation is rapidly changing. Using aerial counts in wet and dry season in 2010 and 2013, this study assessed the trend, population status and distribution of the African buffalo and common waterbuck in the Northern Tanzania and Southern Kenya borderland. Both species were rare in the borderland, with the Amboseli region had the highest number of buffalo (241.5 ± 29.9), followed by Magadi/Namanga (58.0 ± 22.0), West Kilimanjaro (38.8 ± 34.9), and lastly Lake Natron (14.5 ± 9.0) areas. In terms of density, Amboseli also led with 0.03 ± 0.00 (buffalo per km2), but rest had similar densities of 0.01 ± 0.00 buffalo per km2. In terms of percent changes in buffalo, Amboseli area had a positive increase (+10.59 ± 27.71), but with a negative growth of -17.12 in the dry season. All other changes in all locations had negative (decline) buffalo numbers over time. For waterbuck numbers, Amboseli area also led with 12.3 ± 3.9 waterbuck), followed by Magadi/Namanga (10.3 ± 3.7.0), Lake Natron (3.8 ± 3.4), and lastly West Kilimanjaro (0.5 ± 0.5) areas. In terms of waterbuck density, they were low and less than 0.00 ± 0.00 per km2. For percent changes in waterbuck numbers, Magadi/Namanga had higher positive change (+458.33 ± 291.67), but all other locations had negative (decline) changes with the worst being West Kilimanjaro and Lake Natron areas. Further, buffalo number was dependent (p = 0.008) on the season, with numbers being higher in the wet season than dry season. For waterbuck, numbers were independent (p = 0.72) of the season, with numbers being similar across seasons. The findings of this study showed that both species were negatively affected by drought. We recommend a constant joint monitoring program between Kenya and Tanzania, and jointly combat poaching, habitat fragmentation and encroachment to build viable populations in the borderland.展开更多
The Maasai ostrich (Struthio camelus) is a the largest avian species in East Africa and though it’s not considered to be a species of conservation concern, some populations are on the decline and this is attributed t...The Maasai ostrich (Struthio camelus) is a the largest avian species in East Africa and though it’s not considered to be a species of conservation concern, some populations are on the decline and this is attributed to bush meat activities, predation on their eggs illegal consumption by humans, habitat destruction and forage competition with other large wildlife species. Climate change is also emerging to be another major threat due to interference with food availability which in turn interferes with the breeding rhythm. Thus, this study examined the population status, trend and distribution of the Maasai ostrich in the Southern Kenya and Northern Tanzania borderland after the 2007 to 2009 drought. The results showed that the species was found across the entire borderland but the Amboseli region had the highest number and density of Maasai ostrich (726.00 ± 100.9;0.08 ± 0.01 ostriches per km<sup>2</sup>), followed by Lake Natron area (330.8 ± 69.8;0.05 ± 0.01 ostriches per km<sup>2</sup>) and the least was in West Kilimanjaro (85.5 ± 18.0;0.03 ± 0.01 ostriches per km<sup>2</sup>). Drought caused a decline in the population of the Maasai ostrich but the Amboseli area experienced the highest decline in density (?13.44 ± 12.61) compared to other borderland sectors. However, the populations increased in most sectors after the drought, and wet season numbers and densities were higher than the dry season. The highest positive increase in number and density was in Lake Natron area (+85.65 ± 91.06) followed by West Kilimanjaro (+68.39 ± 59.54), and the least was in the Magadi area (+22.26 ± 32.05). There is a need to enhance conservation of avian species like the Maasai ostrich other than just focusing on the charismatic species such as the African elephant and black rhino. We therefore recommend joint collaboration in monitoring all large wildlife populations across the Kenya-Tanzania borderland with a view of understanding their status, trend and best management actions that can enhance their conservation.展开更多
We examined the population status, trend and distribution of Gerenuk, Fringe-eared Oryx and Lesser kudu in the Northern Tanzania and Southern Kenya borderland after the 2007 to 2009 drought. The species were character...We examined the population status, trend and distribution of Gerenuk, Fringe-eared Oryx and Lesser kudu in the Northern Tanzania and Southern Kenya borderland after the 2007 to 2009 drought. The species were characterized by low numbers and sparsely distributed in the borderland but were more prevalent and abundant in the Amboseli region. However, West Kilimanjaro had the highest positive change in density between 2010 and 2013 [Gerenuk = +1650.48 ± 1150.31, lesser kudu = +912.78 ± 487.63 and Fringe-eared Oryx = +366.65 ± 233.32]. Changes in density and composition varied seasonally among the different sectors of the borderland, with Gerenuk having the highest change in the Amboseli area during the wet season. Lesser kudu had the highest change in Amboseli and Kilimanjaro during the wet season while Fringe-eared Oryx had the highest change in the wet season in West Kilimanjaro area. Spatial distribution of the species varied seasonally and across different sectors of the borderland. In the dry season, Gerenuk exhibited a clumped distribution mainly in Amboseli National Park, and between Natron and West Kilimanjaro but in the wet season, it spread out more though higher concentrations were still found Amboseli and West Kilimanjaro. Lesser concentrated in mostly in West Kilimanjaro and Amboseli during the dry season but was widely dispersed during the wet season. Similarly, during the dry season, the Fringe-eared Oryx was confined in the Amboseli and West Kilimanjaro areas but during the wet season, it much more spread out with clusters in the Mbirikani area of the Amboseli region and a few places in Magadi, Natron and West Kilimanjaro. Management implications of the findings obtained in this study area here-in discussed.展开更多
BACKGROUND Arterial stiffness,as assessed by aortic ultrasound and pulse wave velocity,is associated with incident hypertension.However,there is still no consensus on whether the augmentation index(AI)affects new onse...BACKGROUND Arterial stiffness,as assessed by aortic ultrasound and pulse wave velocity,is associated with incident hypertension.However,there is still no consensus on whether the augmentation index(AI)affects new onset of hypertension.This study investigated the relationship of radial AI(r AI)and incident hypertension in a Chinese community-based population without hypertension at baseline.METHOD A total of 1,615 Chinese non-hypertensive participants from an atherosclerosis cohort in Beijing,China were included in our analysis.Baseline r AI normalized to heart rate of 75 beats/min(r AIp75)was obtained using HEM-9000 AI.New-onset hypertension was defined as blood pressure≥140/90 mm Hg or self-reported hypertension or taking anti-hypertensive medications at the follow up survey.Multivariate regression models were used to evaluate the impact of r AIp75 on the risk of new-onset hypertension.RESULTS After a mean 2.35-year follow-up,213(13.19%)participants developed incident hypertension.No significant relation between r AIp75 and incident hypertension was observed in the whole population after adjustment for possible confounders(adjusted odds ratio(OR)and 95%confidence interval(CI):1.09[0.95-1.27];P=0.2260).However,r AIp75 was significantly associated with incident hypertension in women,but not in men(adjusted OR and 95%CI:1.29[1.06-1.56],P=0.0113 for women;0.91[0.72-1.15],P=0.4244 for men;P for interaction=0.0133).CONCLUSIONS Sex modified the effect of the r AI on incident hypertension in a Chinese,community-based,non-hypertensive population.Screening of the r AI could be considered in women with a high risk of hypertension for the purpose of primary intervention.展开更多
[Objective] The aim was to study the dynamic variation of extinction coefficient of corn population, so as to improve the accuracy of assessment on net primary productivity （NPP） or yield. [Method] Based on the data...[Objective] The aim was to study the dynamic variation of extinction coefficient of corn population, so as to improve the accuracy of assessment on net primary productivity （NPP） or yield. [Method] Based on the data of photosynthetic active radiation and leaf area index during corn growing season （from May to September） in 2006, observed in Jinzhou observation station of corn farmland ecosystem, China Meteorological Administration, the dynamic variation of extinction coefficient of corn population was analyzed. [Result] There was a great daily variation in the extinction coefficient of corn population during growing season, and the maximum value appeared from 7：00 to 9：00 and from 15：00 to 17：00, while the minimum could be found around 12：00, but the amplitude of variation decreased in tasseling stage. On a large time scale （5 d）, there was a parabolic relationship between extinction coefficient （K） and leaf area index （LAI）, with determination coefficient R2 of 0.960 7. The simulation equation of extinction coefficient, based on the sun elevation angle or leaf area index, had poor accuracy at various time during growing season, so a new dynamic model of extinction coefficient was established, namely K=λ（0.784 8-0.001 6θ）（0.154 8LAI2-0.558 6LAI＋0.654）. [Conclusion] The effect of sun elevation angle and leaf area index on extinction coefficient during corn growing season was considered in the new dynamic model of extinction coefficient, and its simulated result was superior to that of single-factor model.展开更多
Annual freezing and thawing index of 7 meteorological stations along the Qing- hai-Xizang Railway were calculated based on daily maximum and minimum temperature records for 1966-2004. Trends of annual freezing and tha...Annual freezing and thawing index of 7 meteorological stations along the Qing- hai-Xizang Railway were calculated based on daily maximum and minimum temperature records for 1966-2004. Trends of annual freezing and thawing index were analyzed using the Mann-Kendall test and a simple linear regression method. The results show that： 1） The mean annual freezing indices range from 95 to 2300℃·d and the mean annual thawing indices range from 630 to 3250℃·d. The mean annual freezing index of the 7 stations exhibited decreasing trends with decreasing rate of -16.6- -59.1 ℃·d/10a. The mean annual thawing index of these 7 stations showed increasing trends with the related decreasing rate is 19.83-45.6℃·d/10a. 2） The MK trend test indicated the significant decreasing trends （significant at 〈 0.05 significant level） in the annual freezing index for most stations except for Golmud. The significant increasing trends can be observed in the annual thawing index for 4 stations except Golmud and Tuotuohe. Golmud was the only station with no trends in both annual freezing and annual thawing index.展开更多
Populus euphratica Oliv. is widely distributed along the Tarim River. Maintaining stability of P. euphratica population is important to local development. This study explored the static life table, survivorship curves...Populus euphratica Oliv. is widely distributed along the Tarim River. Maintaining stability of P. euphratica population is important to local development. This study explored the static life table, survivorship curves and four function curves (survival rate, cumulative mortality rate, mortality density, and hazard rate), and development index of P. euphratica population in the middle reaches of Tarim River. The results indicated that the age structure of P. euphratica population belonged to positive pyramidal type, which meant young age-class individuals occupied most populations. The number ofⅠ-Ⅱage classes accounted for 66.2% of whole population, and this indicated that there were abundant subsequent seedlings resources to support the growth of P. euphratica population in the middle reaches of Tarim River. The survivorship curve of P. euphratica belonged to the Deevey Ⅲ (concave-type) and the development index was 47.72%. Four function curves revealed that the individuals of P. euphratica sharply decreased at the initial stage and then leveled off at the late stage of survival curve. Time sequence prediction models predicted that the number of midlife individuals would increase in future 10, 20, 30 years, and P. euphratica population grew steadily as a result of rich saplings.展开更多
This paper attempts to assess the vulnerability to climate change of human communities in selected mouzas of Sagar Island,South 24 Parganas District of India. A primary household survey has been conducted to collect d...This paper attempts to assess the vulnerability to climate change of human communities in selected mouzas of Sagar Island,South 24 Parganas District of India. A primary household survey has been conducted to collect data on socio-demographic profile, livelihood strategy, health, food, water, social network, natural disaster and climate variation indicators, were selected for Livelihood Vulnerability Index(LVI) and Livelihood Vulnerability Index-Intergovernmental Panel on Climate Change(LVI-IPCC) analyses to measure and compare the vulnerability of mouzas(administrative unit) currently suffering from frequent flooding, coastal erosion and embankment breaching on an annual basis. Secondary data collected from the Indian Meteorological Department, the Water Resources Information System of India and the Global Sea Level Observing System have been used to identify dynamics of climate change by employing statistical and Geographic Information System(GIS) techniques. A GPS survey has been conducted to identify locations of embankment breaching, and satellite images obtained from the National Aeronautics and Space Administration and U.S. Geological Survey(NASA USGS) Government website have been applied to shoreline and land use change detection, using a supervised maximum likelihood classification. The results indicate that the study area has experienced increasing temperature, changing precipitation patterns, rise in sea level, higher storm surges, shoreline change, constant land loss, embankment breaching and changing land use, which have had impact on vulnerability, particularly of poorer people. The LVI(0.48 to 0.68) and LVI-IPCC(0.04 to 0.14) scores suggest that the populations of Dhablat, Bankimnagar, Sumatinagar, Muri Ganga and Sibpur mouzas are highly vulnerable(LVI scores of 0.60 to 0.68 and LVI-IPCC scores of 0.11 to 0.14) to climate change both because the communities are more exposed to it, and because poor access to food, health facilities and water makes them extremely sensitive to it and lowers their adaptive capacity. The findings of this study could be crucial to framing further development and adaptation strategies relating to climate change, and to safeguarding the estuarine ecosystem and the vulnerable population.展开更多
基金This study received financial support from the Science and Technology Department of Yunnan University,China(2019YNU002)Major Program for Basic Research Project of Yunnan Province,China(202101BC070002)the Special Foundation for National Science and Technology Basic Resources Investigation of China(2019FY202300).
文摘Pseudotsuga forrestii is a relict evergreen coniferous tree species in Pinaceae endemic to China.P.forrestii tree numbers have greatly decreased due to deforestation,over-utilization and habitat degradation.Here we clarify P.forrestii community types,structure,species diversity,seedling recruitments and growth trends.We identified four P.forrestii community types:(1)Pseudotsuga forrestii-Quercus guyavifolia-Acer davidii evergreen coniferous and broad-leaved mixed forest;(2)Pseudotsuga forrestii-Pinus yunnanensis-Quercus guyavifolia evergreen coniferous and broad-leaved mixed forest;(3)Pseudotsuga forrestii evergreen coniferous forest;(4)Pseudotsuga forrestii-Abies georgei var.smithii evergreen coniferous forest.P.forrestii forests are characterized by both warm temperate and temperate affinities.Simpson diversity,Pielou evenness,Shannon-Wiener diversity indices ranged from 0.75 to 0.76,0.74-0.81,and 1.62-1.93,respectively,with no significant differences among the four forest types.The forest stratification was multilayered.The canopy layer was generally 10-25 m tall,with the emergent layer reached 25-42 m.DBH and age structures of P.forrestii showed multimodal distributions.Its maximum age P.forrestii was 570 years with a DBH of 143 cm.The growth of annual ring width of P.forrestii was slow,and generally decreased with age,whereas the basal area at the breast height increased with age.Established seedlings/saplings were mainly found in unstable micro-habitats.Regeneration of P.forrestii depends on moderate natural disturbances.Finally,we provide recommendations for P.forrestii conservation.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.31572280 and 31071939)
文摘Background: China is one of the countries with abundant waterbird diversity. Over the past decades, China's waterbirds have suffered increasing threats from direct and indirect human activities. It is important to clarify the population trends of and threats to waterbirds as well as to put forward conservation recommendations.Methods: We collected data of population trends of a total of 260 waterbird species in China from Wetlands International database. We calculated the number of species with increasing, declining, stable, and unknown trends. We collected threatened levels of waterbirds from the Red List of China's Vertebrates(2016), which was compiled according to the IUCN criteria of threatened species. Based on literature review, we refined the major threats to the threatened waterbird species in China.Results: Of the total 260 waterbird species in China, 84 species(32.3%) exhibited declining, 35 species(13.5%) kept stable, and 16 species(6.2%) showed increasing trends. Population trends were unknown for 125 species(48.1%). There was no significant difference in population trends between the migratory(32.4% decline) and resident(31.8% decline) species or among waterbirds distributed exclusively along coasts(28.6% decline), inland(36.6% decline), and both coasts and inland(32.5% decline). A total of 38 species(15.1% of the total) were listed as threatened species and 27 species(10.8% of the total) Near Threatened species. Habitat loss was the major threat to waterbirds, with 32 of the total 38(84.2%) threatened species being affected. In addition, 73.7%(28 species), 71.1%(27 species), and 57.9%(22 species) of the threatened species were affected by human disturbance, environmental pollution, and illegal hunting, respectively.Conclusions: We propose recommendations for waterbird conservation, including(1) strengthening conservation of nature wetlands and restoration of degraded wetlands,(2) enhancing public awareness on waterbird conservation,(3) improving the enforcement of Wildlife Protection Law and cracking down on illegal hunting,(4) carrying out longterm waterbird surveys to clarify population dynamics,(5) restoring populations of highly-threatened species through artificial intervention, and(6) promoting international and regional exchanges and cooperation to share information in waterbirds and their conservation.
基金provided by project CGL2008-02567 of the Dirección General de Investigación
文摘The Great Bustard(Otis tarda) world population is estimated to be 44100–57000 individuals in 2010,of which about 57–70% occur in Spain,15–25% in European Russia,4–10% in China,Mongolia and south-eastern Russia,3–4% in Portugal,3% in Hungary,1–2% in Turkey,and smaller numbers in ten other countries.The reliability of current censuses and estimates may be described as high for a large fraction of the world population(67–75%),and low for the remain-ing 25–33%(including Russia,Mongolia,China,Turkey,Ukraine,Iran and Kazakhstan).In spite of continued declines reported for some countries(e.g.,Turkey,Iran,China) ,the present survey suggests that total numbers have not significantly decreased worldwide during the last decade,as opposed to the globally declining trend currently assumed.This is due to a large fraction of the world total living in countries whose overall surveys are apparently stable(e.g.,Spain,Portugal),after a noticeable recovery during the last few decades once the hunting ban was established.Only 6–10% of the world total is apparently still decreasing,mostly due to agricultural intensification,other causes of habitat degradation,and locally,also illegal hunting and collision with power lines.A small fraction of the world population(3–4%),is clearly(Germany,Austria) or apparently(Hungary) increasing,due to management and conservation measures.Finally,19–22% of the world total has an uncertain status,due to inaccurate current or past censuses which prevent establishing reliable population trends.We recommend 1)keeping conservation efforts and the species’protection status worldwide,and 2)carrying out urgently nation-wide surveys in countries with low quality estimates,in order to confirm world numbers and trends.
文摘The characteristics of drought in Xinjiang Uygur Autonomous Region(Xinjiang),China have changed due to changes in the spatiotemporal patterns of temperature and precipitation,however,the effects of temperature and precipitation—the two most important factors influencing drought—have not yet been thoroughly explored in this region.In this study,we first calculated the standard precipitation evapotranspiration index(SPEI)in Xinjiang from 1980 to 2020 based on the monthly precipitation and monthly average temperature.Then the spatiotemporal characteristics of temperature,precipitation,and drought in Xinjiang from 1980 to 2020 were analyzed using the Theil-Sen median trend analysis method and Mann-Kendall test.A series of SPEI-based scenario-setting experiments by combining the observed and detrended climatic factors were utilized to quantify the effects of individual climatic factor(i.e.,temperature and precipitation).The results revealed that both temperature and precipitation had experienced increasing trends at most meteorological stations in Xinjiang from 1980 to 2020,especially the spring temperature and winter precipitation.Due to the influence of temperature,trends of intensifying drought have been observed at spring,summer,autumn,and annual scales.In addition,the drought trends in southern Xinjiang were more notable than those in northern Xinjiang.From 1980 to 2020,temperature trends exacerbated drought trends,but precipitation trends alleviated drought trends in Xinjiang.Most meteorological stations in Xinjiang exhibited temperature-dominated drought trend except in winter;in winter,most stations exhibited precipitation-dominated wetting trend.The findings of this study highlight the importance of the impact of temperature on drought in Xinjiang and deepen the understanding of the factors influencing drought.
基金Nacional de Promoción Científica y Tecnológica(Grant:PICTO 2010-0111)the Instituto Antártico Argentino-Dirección Nacional del Antártico(PINST-05)provided financial and logistical support.
文摘In this work,we report long-term trends in the abundance and breeding performance of Adélie penguins(Pygoscelis adeliae)nesting in three Antarctic colonies(i.e.,at Martin Point,South Orkneys Islands;Stranger Point/Cabo Funes,South Shetland Islands;and Esperanza/Hope Bay in the Antarctic Peninsula)from 1995/96 to 2022/23.Using yearly count data of breeding groups selected,we observed a decline in the number of breeding pairs and chicks in crèche at all colonies studied.However,the magnitude of change was higher at Stranger Point than that in the remaining colonies.Moreover,the index of breeding success,which was calculated as the ratio of chicks in crèche to breeding pairs,exhibited no apparent trend throughout the study period.However,it displayed greater variability at Martin Point compared to the other two colonies under investigation.Although the number of chicks in crèche of Adélie penguins showed a declining pattern,the average breeding performance was similar to that reported in gentoo penguin colonies,specifically,those undergoing a population increase(even in sympatric colonies facing similar local conditions).Consequently,it is plausible to assume a reduction of the over-winter survival as a likely cause of the declining trend observed,at least in the Stranger Point and Esperanza colonies.However,we cannot rule out local effects during the breeding season affecting the Adélie population of Martin Point.
文摘In this special issue of the Journal of Sport and Health Science, analyses of the most recent national prevalence esti- mates from the 2016 Physical Activity and Fimess in China-- The Youth Study （PAFCTYS） are presented. These include the prevalence of moderate-to-vigorous physical activity （MVPA）.
文摘Data on lion skull measurements taken were collected and analyzed to determine trends in trophy size as an indicator of population size, and area of origin among the concessioned hunting areas in Zambia for the period 1967-2000. A comparison of trophy quality was also made with Tanzania and Zimbabwe which were the other two key sources of lion trophies in Africa. It was assumed that a comprehensive analysis of lion trophy sizes obtained from trophy hunting would be used as an indicator of hunting pressure on lion populations in Zambia. This approach was used because trophy size is an index of abundance particularly for species such as lion which are difficult to count using conventional census methods. Record lion trophies from Safari Club International rating were also collected and assessed to compare trophy quality obtained from Zambia and those of Tanzania and Zimbabwe for the same period 1967-2000 (33 years). Results obtained suggested that Zambia’s contribution to the record trophies under Safari Club International did not decline in the intervening period 1967-2000 and could not be used as an effective indicator of lion population in Zambia. At regional level, Zambia had second highest 24%, after Tanzania 56%, while Zimbabwe was third, 20%. It was found that the size of skulls could not be used as an effective indicator of population size as the record trophies did not decline while the population was alleged to have declined on the continent. Other factors, such as genetic, low prey densities, snaring, poisoning and problem animal control needed to be investigated to determine their impact on the lion population status.
基金Supported by Bundesministerium für Bildung und Forschung(BMBF),No.01 ZZ 0103
文摘AIM To investigate the association between hepatic steatosis and change in left ventricular mass index(LVMI) over five years, and examine whether systolic and diastolic blood pressures are mediators of the association between hepatic steatosis and LVMI using a general population sample.METHODS We analyzed data from the Study of Health in Pomerania. The study population comprised 1298individuals aged 45 to 81 years. Hepatic steatosis was defined as the presence of a hyperechogenic pattern of the liver together with elevated serum alanine transferase levels. Left ventricular mass was determined echocardiographically and indexed to height2.7. Path analyses were conducted to differentiate direct and indirect paths from hepatic steatosis to LVMI encompassing systolic and diastolic blood pressure as potential mediating variables.RESULTS Hepatic steatosis was a significant predictor for all measured echocardiographic characteristics at baseline. Path analyses revealed that the association of hepatic steatosis with LVMI change after five years was negligibly small(β =-0.12, s.e. = 0.21, P = 0.55). Systolic blood pressure at baseline was inversely associated with LVMI change(β =-0.09, s.e. = 0.03, P < 0.01), while no association between diastolic blood pressure at baseline and LVMI change was evident(β = 0.03, s.e. = 0.05, P = 0.56). The effect of the indirect path from hepatic steatosis to LVMI via systolic baseline blood pressure was small(β =-0.20, s.e. = 0.10, P = 0.07). No indirect effect was observed for the path via diastolic baseline blood pressure(β = 0.03, s.e. = 0.06, P = 0.60). Similar associations were observed in the subgroup of individuals not receiving beta-blockers, calcium channel blockers, or drugs acting on the reninangiotensin system.CONCLUSION Baseline associations between hepatic steatosis and LVMI do not extend to associations with LVMI change after five years. More studies are needed to study the longitudinal effects of hepatic steatosis on LVMI.
基金The Fundamental Research Grant Scheme from the Ministry of Higher Education Malaysia under contract No.FRG0467-2017。
文摘The population parameters of blood cockles,Tegillarca granosa in the intertidal zone of Marudu Bay,Sabah,Malaysia were investigated based on monthly length-weight frequency data(July 2017 to June 2018).A total of 279 cockle individuals with shell length and weight ranging from 27.7 mm to 82.2 mm and 13.11 g to 192.7 g were subjected to analysis.T.granosa in Marudu Bay showed a consistent moderately high condition index 4.98±0.86 throughout the year.The exponent b of the length-weight relationship was 2.6 demonstrating negative allometric growth.The estimated asymptotic length(L_(∞)),growth coefficient(K)and growth performance(Ф)of the T.granosa population in Marudu Bay were estimated at 86.68 mm,0.98 a^(-1) and 3.87,respectively.The observed maximum shell length was 82.55 mm and the predicted maximum shell length was 84.44 mm with estimated maximum life span(t_(max))of 3.06 years.The estimated mean lengths at the end of 2,4,6,8,10 and 12 months of age were 21.31 mm,31.16 mm,39.53 mm,46.63 mm,52.67 mm and 57.79 mm.Total,natural,and fishing mortalities were estimated at 2.39 a^(-1),1.32 a^(-1) and 1.07 a^(-1).The exploitation level(E)was 0.45.Results of the current study also demonstrated that T.granosa in the Marudu Bay has two major recruitment peaks;one in March and another in October.The exploitation level revealed that natural stock of T.granosa in the Marudu Bay was approaching the maximum exploitation level.If such trend continues or demand for T.granosa is increasing,coupled with no effective fisheries management in place,possibility of the T.granosa population in the Marudu Bay to collapse is likely to elevate.
基金the National Natural Science Foundation of China(Grant No.51679020)the Science and Technology Research Program of Chongqing Municipal Education Commission(Grant No.KJQN202100731).
文摘Decelerating open-channel flow is a type of flow that gradually moves forward with decreasing velocity and increasing water depth.Although all flow parameters change along the streamwise direction,previous studies have revealed that these parameters’vertical distributions at different sections can be universally described with a single profile when being nondimensionalised by appropriate scales.This study focuses on the population trends of spanwise rotational motions at various sections along the main flow direction by particle imaging velocimetry(PIV)measurement.The wall-normal population distributions of density,radius,swirling strength,and convection velocity of the prograde and retrograde motions show similar trends in uniform open-channel flows.The dimensionless representation is invariant along the main flow direction.This study’s results indicate the self-similar characteristic of population trends of spanwise rotational motions prevails in decelerating open-channel flow.
基金Supported by the Special Project for the Grass-roots Units of Shandong Meteorological Bureau(2023SDJC14).
文摘Based on the monthly precipitation data of 116 meteorological stations in Shandong Province during 1970-2021,standardized precipitation index(SPI)was calculated,and the methods of linear fitting,mutation test and Morlet wavelet analysis were used to analyze the change trend and temporal and spatial distribution characteristics of SPI index in the past 52 years.The results show that there were more normal years in Shandong Province,and the frequency reached 38.46%.There was severe drought in the 1980s and more wet years after 2003.SPI index showed an upward trend in spring,summer and winter but a weak arid trend in autumn.In addition,intense dry weather was more frequent in summer.Spatially,the climate was normal or humid in most areas of Shandong Province.The regions with more wet years were located in the central and northeast Shandong and the peninsula,while the climate was normal in the southwest and north of Shandong.The areas with more dry years were mainly located in the northwest of Shandong Province.There was mainly local and global drought in Shandong Province,and the arid area showed a decreasing trend.In the past 52 years,Shandong Province experienced quasi-4 times of alternation between dry and wet climate.The long period of 21 a was the first main period,and the climate would be still wet in Shandong Province in the future.In terms of mutation,the climate in Shandong Province became humid after 2003,and 2003 was the mutation point.After the abrupt change,the climate changed from gradually drying to wetting.
文摘Even though over many years the IUCN has considered the African buffalo and waterbuck and abundant species in Africa with no conservation concern, the situation is rapidly changing. Using aerial counts in wet and dry season in 2010 and 2013, this study assessed the trend, population status and distribution of the African buffalo and common waterbuck in the Northern Tanzania and Southern Kenya borderland. Both species were rare in the borderland, with the Amboseli region had the highest number of buffalo (241.5 ± 29.9), followed by Magadi/Namanga (58.0 ± 22.0), West Kilimanjaro (38.8 ± 34.9), and lastly Lake Natron (14.5 ± 9.0) areas. In terms of density, Amboseli also led with 0.03 ± 0.00 (buffalo per km2), but rest had similar densities of 0.01 ± 0.00 buffalo per km2. In terms of percent changes in buffalo, Amboseli area had a positive increase (+10.59 ± 27.71), but with a negative growth of -17.12 in the dry season. All other changes in all locations had negative (decline) buffalo numbers over time. For waterbuck numbers, Amboseli area also led with 12.3 ± 3.9 waterbuck), followed by Magadi/Namanga (10.3 ± 3.7.0), Lake Natron (3.8 ± 3.4), and lastly West Kilimanjaro (0.5 ± 0.5) areas. In terms of waterbuck density, they were low and less than 0.00 ± 0.00 per km2. For percent changes in waterbuck numbers, Magadi/Namanga had higher positive change (+458.33 ± 291.67), but all other locations had negative (decline) changes with the worst being West Kilimanjaro and Lake Natron areas. Further, buffalo number was dependent (p = 0.008) on the season, with numbers being higher in the wet season than dry season. For waterbuck, numbers were independent (p = 0.72) of the season, with numbers being similar across seasons. The findings of this study showed that both species were negatively affected by drought. We recommend a constant joint monitoring program between Kenya and Tanzania, and jointly combat poaching, habitat fragmentation and encroachment to build viable populations in the borderland.
文摘The Maasai ostrich (Struthio camelus) is a the largest avian species in East Africa and though it’s not considered to be a species of conservation concern, some populations are on the decline and this is attributed to bush meat activities, predation on their eggs illegal consumption by humans, habitat destruction and forage competition with other large wildlife species. Climate change is also emerging to be another major threat due to interference with food availability which in turn interferes with the breeding rhythm. Thus, this study examined the population status, trend and distribution of the Maasai ostrich in the Southern Kenya and Northern Tanzania borderland after the 2007 to 2009 drought. The results showed that the species was found across the entire borderland but the Amboseli region had the highest number and density of Maasai ostrich (726.00 ± 100.9;0.08 ± 0.01 ostriches per km<sup>2</sup>), followed by Lake Natron area (330.8 ± 69.8;0.05 ± 0.01 ostriches per km<sup>2</sup>) and the least was in West Kilimanjaro (85.5 ± 18.0;0.03 ± 0.01 ostriches per km<sup>2</sup>). Drought caused a decline in the population of the Maasai ostrich but the Amboseli area experienced the highest decline in density (?13.44 ± 12.61) compared to other borderland sectors. However, the populations increased in most sectors after the drought, and wet season numbers and densities were higher than the dry season. The highest positive increase in number and density was in Lake Natron area (+85.65 ± 91.06) followed by West Kilimanjaro (+68.39 ± 59.54), and the least was in the Magadi area (+22.26 ± 32.05). There is a need to enhance conservation of avian species like the Maasai ostrich other than just focusing on the charismatic species such as the African elephant and black rhino. We therefore recommend joint collaboration in monitoring all large wildlife populations across the Kenya-Tanzania borderland with a view of understanding their status, trend and best management actions that can enhance their conservation.
文摘We examined the population status, trend and distribution of Gerenuk, Fringe-eared Oryx and Lesser kudu in the Northern Tanzania and Southern Kenya borderland after the 2007 to 2009 drought. The species were characterized by low numbers and sparsely distributed in the borderland but were more prevalent and abundant in the Amboseli region. However, West Kilimanjaro had the highest positive change in density between 2010 and 2013 [Gerenuk = +1650.48 ± 1150.31, lesser kudu = +912.78 ± 487.63 and Fringe-eared Oryx = +366.65 ± 233.32]. Changes in density and composition varied seasonally among the different sectors of the borderland, with Gerenuk having the highest change in the Amboseli area during the wet season. Lesser kudu had the highest change in Amboseli and Kilimanjaro during the wet season while Fringe-eared Oryx had the highest change in the wet season in West Kilimanjaro area. Spatial distribution of the species varied seasonally and across different sectors of the borderland. In the dry season, Gerenuk exhibited a clumped distribution mainly in Amboseli National Park, and between Natron and West Kilimanjaro but in the wet season, it spread out more though higher concentrations were still found Amboseli and West Kilimanjaro. Lesser concentrated in mostly in West Kilimanjaro and Amboseli during the dry season but was widely dispersed during the wet season. Similarly, during the dry season, the Fringe-eared Oryx was confined in the Amboseli and West Kilimanjaro areas but during the wet season, it much more spread out with clusters in the Mbirikani area of the Amboseli region and a few places in Magadi, Natron and West Kilimanjaro. Management implications of the findings obtained in this study area here-in discussed.
基金supported by the University of Michigan-Peking University Health Science Centre(UMHS-PUHSC)Joint Institute for Translational and Clinical Research and the Fundamental Research Funds for the Central Universities(grant numbers:BMU20110177 and BMU20160530)the National Key Research and Development Program of China(grant number:2017YFC1307704)+2 种基金the Scientific Research Seed Fund of Peking University First Hospital(grant numbers:2018SF003 and 2018SF071)Projects of the National Natural Science Foundation of China(grant number:81703288)the Key Laboratory of Molecular Cardiovascular Sciences(Peking University),Ministry of Education and NHC Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides。
文摘BACKGROUND Arterial stiffness,as assessed by aortic ultrasound and pulse wave velocity,is associated with incident hypertension.However,there is still no consensus on whether the augmentation index(AI)affects new onset of hypertension.This study investigated the relationship of radial AI(r AI)and incident hypertension in a Chinese community-based population without hypertension at baseline.METHOD A total of 1,615 Chinese non-hypertensive participants from an atherosclerosis cohort in Beijing,China were included in our analysis.Baseline r AI normalized to heart rate of 75 beats/min(r AIp75)was obtained using HEM-9000 AI.New-onset hypertension was defined as blood pressure≥140/90 mm Hg or self-reported hypertension or taking anti-hypertensive medications at the follow up survey.Multivariate regression models were used to evaluate the impact of r AIp75 on the risk of new-onset hypertension.RESULTS After a mean 2.35-year follow-up,213(13.19%)participants developed incident hypertension.No significant relation between r AIp75 and incident hypertension was observed in the whole population after adjustment for possible confounders(adjusted odds ratio(OR)and 95%confidence interval(CI):1.09[0.95-1.27];P=0.2260).However,r AIp75 was significantly associated with incident hypertension in women,but not in men(adjusted OR and 95%CI:1.29[1.06-1.56],P=0.0113 for women;0.91[0.72-1.15],P=0.4244 for men;P for interaction=0.0133).CONCLUSIONS Sex modified the effect of the r AI on incident hypertension in a Chinese,community-based,non-hypertensive population.Screening of the r AI could be considered in women with a high risk of hypertension for the purpose of primary intervention.
基金Supported by Major Project of Chinese National Programs for Fundamental Research and Development(2006CB400502)National Natural Science Funds for Distinguished Young Scholar(40625015)~~
文摘[Objective] The aim was to study the dynamic variation of extinction coefficient of corn population, so as to improve the accuracy of assessment on net primary productivity （NPP） or yield. [Method] Based on the data of photosynthetic active radiation and leaf area index during corn growing season （from May to September） in 2006, observed in Jinzhou observation station of corn farmland ecosystem, China Meteorological Administration, the dynamic variation of extinction coefficient of corn population was analyzed. [Result] There was a great daily variation in the extinction coefficient of corn population during growing season, and the maximum value appeared from 7：00 to 9：00 and from 15：00 to 17：00, while the minimum could be found around 12：00, but the amplitude of variation decreased in tasseling stage. On a large time scale （5 d）, there was a parabolic relationship between extinction coefficient （K） and leaf area index （LAI）, with determination coefficient R2 of 0.960 7. The simulation equation of extinction coefficient, based on the sun elevation angle or leaf area index, had poor accuracy at various time during growing season, so a new dynamic model of extinction coefficient was established, namely K=λ（0.784 8-0.001 6θ）（0.154 8LAI2-0.558 6LAI＋0.654）. [Conclusion] The effect of sun elevation angle and leaf area index on extinction coefficient during corn growing season was considered in the new dynamic model of extinction coefficient, and its simulated result was superior to that of single-factor model.
基金Knowledge Innovation Program of Xinjiang Institute of Ecology and Geography, CAS, No.0571041
文摘Annual freezing and thawing index of 7 meteorological stations along the Qing- hai-Xizang Railway were calculated based on daily maximum and minimum temperature records for 1966-2004. Trends of annual freezing and thawing index were analyzed using the Mann-Kendall test and a simple linear regression method. The results show that： 1） The mean annual freezing indices range from 95 to 2300℃·d and the mean annual thawing indices range from 630 to 3250℃·d. The mean annual freezing index of the 7 stations exhibited decreasing trends with decreasing rate of -16.6- -59.1 ℃·d/10a. The mean annual thawing index of these 7 stations showed increasing trends with the related decreasing rate is 19.83-45.6℃·d/10a. 2） The MK trend test indicated the significant decreasing trends （significant at 〈 0.05 significant level） in the annual freezing index for most stations except for Golmud. The significant increasing trends can be observed in the annual thawing index for 4 stations except Golmud and Tuotuohe. Golmud was the only station with no trends in both annual freezing and annual thawing index.
基金the National Science and Technology Support Program Projects (2009BAC54B04) for financing this research
文摘Populus euphratica Oliv. is widely distributed along the Tarim River. Maintaining stability of P. euphratica population is important to local development. This study explored the static life table, survivorship curves and four function curves (survival rate, cumulative mortality rate, mortality density, and hazard rate), and development index of P. euphratica population in the middle reaches of Tarim River. The results indicated that the age structure of P. euphratica population belonged to positive pyramidal type, which meant young age-class individuals occupied most populations. The number ofⅠ-Ⅱage classes accounted for 66.2% of whole population, and this indicated that there were abundant subsequent seedlings resources to support the growth of P. euphratica population in the middle reaches of Tarim River. The survivorship curve of P. euphratica belonged to the Deevey Ⅲ (concave-type) and the development index was 47.72%. Four function curves revealed that the individuals of P. euphratica sharply decreased at the initial stage and then leveled off at the late stage of survival curve. Time sequence prediction models predicted that the number of midlife individuals would increase in future 10, 20, 30 years, and P. euphratica population grew steadily as a result of rich saplings.
文摘This paper attempts to assess the vulnerability to climate change of human communities in selected mouzas of Sagar Island,South 24 Parganas District of India. A primary household survey has been conducted to collect data on socio-demographic profile, livelihood strategy, health, food, water, social network, natural disaster and climate variation indicators, were selected for Livelihood Vulnerability Index(LVI) and Livelihood Vulnerability Index-Intergovernmental Panel on Climate Change(LVI-IPCC) analyses to measure and compare the vulnerability of mouzas(administrative unit) currently suffering from frequent flooding, coastal erosion and embankment breaching on an annual basis. Secondary data collected from the Indian Meteorological Department, the Water Resources Information System of India and the Global Sea Level Observing System have been used to identify dynamics of climate change by employing statistical and Geographic Information System(GIS) techniques. A GPS survey has been conducted to identify locations of embankment breaching, and satellite images obtained from the National Aeronautics and Space Administration and U.S. Geological Survey(NASA USGS) Government website have been applied to shoreline and land use change detection, using a supervised maximum likelihood classification. The results indicate that the study area has experienced increasing temperature, changing precipitation patterns, rise in sea level, higher storm surges, shoreline change, constant land loss, embankment breaching and changing land use, which have had impact on vulnerability, particularly of poorer people. The LVI(0.48 to 0.68) and LVI-IPCC(0.04 to 0.14) scores suggest that the populations of Dhablat, Bankimnagar, Sumatinagar, Muri Ganga and Sibpur mouzas are highly vulnerable(LVI scores of 0.60 to 0.68 and LVI-IPCC scores of 0.11 to 0.14) to climate change both because the communities are more exposed to it, and because poor access to food, health facilities and water makes them extremely sensitive to it and lowers their adaptive capacity. The findings of this study could be crucial to framing further development and adaptation strategies relating to climate change, and to safeguarding the estuarine ecosystem and the vulnerable population.
