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Seedling dynamics differ between canopy species and understory species in a tropical seasonal rainforest,SW China
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作者 Libing Pan Xiaoyang Song +2 位作者 Wenfu Zhang Jie Yang Min Cao 《Plant Diversity》 SCIE CAS CSCD 2024年第5期671-677,共7页
We used 11 years of census data from 450 seedling quadrats established in a 20-ha forest dynamics plot to study seedling dynamics in tree species of a tropical seasonal rainforest in Xishuangbanna,southwestern China.W... We used 11 years of census data from 450 seedling quadrats established in a 20-ha forest dynamics plot to study seedling dynamics in tree species of a tropical seasonal rainforest in Xishuangbanna,southwestern China.We found that overall seedling recruitment rate and relative growth rate were higher in the rainy season than in the dry season.Both the recruitment rate of seedlings from canopy tree species(two species)and the relative growth rate of seedlings from understory species(nine species)were higher in the rainy season than in the dry season.However,in the rainy season,the recruitment rate of seedlings was higher for canopy tree species than for understory tree species.In addition,relative growth rate of seedlings was higher in the canopy species than in understory seedlings in the dry season.We also observed that,in both rainy and dry seasons,mortality rate of seedlings was higher for canopy species than for understory species.Overall,canopy tree species appear to have evolved a flexible strategy to adapt to the seasonal changes of a monsoon climate.In contrast,understory tree species seem to have adopted a conservative strategy.Specifically,these species mainly release seedlings in the rainy season and maintain relatively stable populations with a lower mortality rate and recruitment rate in both dry and rainy seasons.Our study suggests that canopy and understory seedling populations growing in forest understory may respond to future climate change scenarios with distinct regeneration strategies. 展开更多
关键词 Tropical forest Tree seedling SEASONALITY RECRUITMENT Mortality relative growth rate
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Relative floatability as a criterion for evaluating the separation performance of phosphate from iron 被引量:1
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作者 Azizi Asghar Seyyed Alizade Ganji Seyyed Mohammad 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2017年第3期451-458,共8页
This work was aimed to study the relative floatability of phosphate flotation by means of kinetic analysis.The relative floatability is important to determine how selectively the phosphate is separated from its impuri... This work was aimed to study the relative floatability of phosphate flotation by means of kinetic analysis.The relative floatability is important to determine how selectively the phosphate is separated from its impurities. The effects of pulp pH, solid content, reagents dosage(depressant, collector and co-collector) and conditioning time were investigated on the ratio of the modified rate constant of phosphate to the modified rate constant of iron(relative floatability). The results showed that a large dosage of depressant associated with a low value of collector resulted in a better relative floatability. Increasing the co-collector dosage, conditioning time and pH increased the relative floatability up to a certain value and thereafter resulted in diminishing the relative floatability. Meanwhile, the results indicated that increment of solid concentration increased the relative floatability in range investigated. It was also found that that maximum relative floatability(16.05) could be obtained in pulp pH, 9.32, solid percentage, 30,depressant dosage, 440 g/t, collector dosage, 560 g/t, co-collector dosage, 84.63 g/t and conditioning time,9.43 min. 展开更多
关键词 Phosphate relative floatability Kinetics rate constant Separation
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QTL analysis of leaf photosynthetic rate and related physiological traits in rice(Oryza sativa L.) 被引量:3
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作者 TENG Sheng, QIAN Qian, ZENG Dali, Yasufumi Kunihiro, Hiroshi Fujimoto, HUANG Daman, and ZHU Lihuang, Key Lab for Rice Biology, CNRRI, Hangzhou 310006 Inst of Genetics and Development Biology, the Chinese Academy of Sciences, Beijing 100101 +1 位作者 College of Life Sci, Zhejiang Univ, Hangzhou 310029, China Japan International Res Center for Agri Sci, Tsukuba, Japan 《Chinese Rice Research Newsletter》 2002年第3期4-6,共3页
Photosynthesis is one of the most important factors that influence the biomass and yield. Recently, more attention has been paid to genetic study on rice photosynthesis and rice breeding for the physiological traits r... Photosynthesis is one of the most important factors that influence the biomass and yield. Recently, more attention has been paid to genetic study on rice photosynthesis and rice breeding for the physiological traits related to high efficient photosynthesis. Chlorophyll content, stomatal resistance, and transpiration rate were very important physiological traits related to photosynthesis. But until now, no genetic study on these traits has been reported. A DH population derived from anther culture of ZYQ8/JX17, a typical indica/japonica hybrid was developed, 展开更多
关键词 rate DH Oryza sativa L QTL analysis of leaf photosynthetic rate and related physiological traits in rice
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Heart Rate Distribution and Cause-specific Death in General Population of South China 被引量:1
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作者 刘小清 饶栩栩 +6 位作者 麦劲壮 吴勇 郭成业 石美玲 高向民 邓木兰 连子斌 《South China Journal of Cardiology》 CAS 2005年第2期129-133,共5页
Objectives To analyses heart rate (HR) distribution of healthy adults in the south China community and evaluate relative risk of HR to total cause of death and cardiac cerebral vascular death. Methods Analytical dat... Objectives To analyses heart rate (HR) distribution of healthy adults in the south China community and evaluate relative risk of HR to total cause of death and cardiac cerebral vascular death. Methods Analytical data come from the baseline survey and follow-up visits in the PRC-USA Collaborative Study of Cardiovascular Epidemiology in urban and rural samples of Guangzhou. The baseline survey was initiated in 1983 and 1984, and rescanned in 1987 and 1988. Since 1991 Follow-up visits for endpoint events were carried once every two years. Average follow-up year was 16.2 from baseline to 2000. People excluded from cardiac cerebral vascular disease, diabetes and other various chronic diseases were regarded as "healthy adults". Heart rates of these subjects were measured on resting electrocardiogram. Endpoint evens include: total cause of death, first attack of coronary disease and cerebral vascular events. SAS software was used for analysis. Cox Proportional Hazards model was used to evaluate the impact of HR on total death and cardiac cerebral vascular disease. Results A total of 4570 men and women aged 35-55 years from urban and rural Guangzhou were investigated. 3493 healthy subjects were enrolled in the analysis, including 1694 men and 1799 women. Mean oftheHRis (67.9 ±10.6) beats/min (bpm) in the whole population, (66.3±10.7)bpm in men and (69.3± 10.4) in women. The 52 percentile of the HR was 51 in men and 54 in women. The 952 percentile of the HR was 85 in men and 88 in women. Single correlation analysis showed there was negative relationship between age and HR, but it was only statistical significant in female. Analysis with Cox Proportional Hazards model show that HR 〈 50 bpm tops the risk of total causes of death (1.725)and HR 50-59 bpm decreased the risk of total causes of death (0.843). Relative risk of cardiac cerebral vascular events exceeds 1 when HR 〈 50 and 〉90 bpm (1.486 and 7.008 respectively). It was less than 1 in other groups but there was no significant difference between each group. Conclusions Traditional normal range of HR in adult should be adjusted. In certain extent lower HR is advantageous to decrease cardiac cerebral vascular events, total causes of death and has better prognosis. 展开更多
关键词 Heart rate Normal range relative risk
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Predicting Compensatory Growth and Reproduction in Agricultural Weeds Using a Plant's Growth Rate Trajectory: A Test with Defoliation of Abutilon theophrasti
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作者 David Alexander Wait 《Journal of Agricultural Science and Technology(A)》 2016年第4期255-260,共6页
A plant's capacity to compensate for pest damage as a function of resource availability needs to be predictable in order to apply biocontrol agents effectively. In this research, it was hypothesized that a weedy plan... A plant's capacity to compensate for pest damage as a function of resource availability needs to be predictable in order to apply biocontrol agents effectively. In this research, it was hypothesized that a weedy plant species' capacity to compensate for defoliation is related to how resource availability affects a plant's growth trajectory. Growth rate trajectory is defined as the percent change in relative growth rate or the slope of a plant's relative growth rate. 90 Abutilon theophrasti, a common weed species, in cultivated fields of corn and soybean, grew in a greenhouse for 70 d under three nitrogen (N) fertilization treatments. "Unfertilized" plants were not fertilized, "bulk" fertilized plants received 0.6 g N on day 15 and "exponential" fertilized plants received a total of 0.6 g N supplied at an exponential rate of 10% per day with a starting concentration of 0.02 g N on day 15. On day 25, 15 plants in each N treatment had 75% of total leaf area removed. Biomass and reproductive compensation were determined after 50 d and 70 d of growth. Results showed that bulk plants had the greatest absolute growth, but also the greatest decline in growth rates and the least capacity for compensation. Unfertilized plants had the lowest absolute growth, but declines in growth rates were similar to bulk plants with only a slightly greater compensatory capacity. Exponential plants had intermediate absolute growth, but the least decline in growth rates and the greatest capacity for compensation. This experiment indicates that a plant's growth rate trajectory, and not high or low relative growth rates or N availability per se, can be used to predict a weedy plant's capacity to compensate for herbivory, and has implications for biocontrol of weedy species. 展开更多
关键词 BIOCONTROL compensatory growth HERBIVORY nitrogen fertilization relative growth rate reproductive allocation.
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CO_2, H_2O exchange and stomatal regulation of regenerated Camptotheca acuminata plantlets during ex vitro acclimatization 被引量:1
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作者 WANG Hui-mei LI Yan-hua GAO Yin-xiang ZU Yuan-gang 《Journal of Forestry Research》 SCIE CAS CSCD 2006年第4期273-276,共4页
For finding the changes in CO2, H20 exchange and their stomatal regulation during ex vitro acclimatization of regenerated Camptotheca acuminata plantlets, the net photosynthesis rate (Pn), respiration rate (Ro), l... For finding the changes in CO2, H20 exchange and their stomatal regulation during ex vitro acclimatization of regenerated Camptotheca acuminata plantlets, the net photosynthesis rate (Pn), respiration rate (Ro), light compensation point (Lc) and light saturation point (Ls), transpiration rate (Tr), stomatal conductance (gs) and water use efficiency(WUE) were measured during 37 days of ex vitro acclimatization. The results showed that Pn sharply increased until 29 days, then slightly decreased. A substantial decrease in Lc and a substantial increase of Ls in the former two weeks were observed, indicating the light regime enlargement for effective leaf photosynthesis. Tr and gs abruptly decreased during the first week then linearly increased until 29days ex vitro acclimatization, reflecting the strong regulation effect of stomata on water changes of ex vitro acclimating plantlets. Stomatal regulation effect on CO2 exchange was different from that on water exchange, i.e. P, was almost independent of gs during the first week, while P. was significantly correlated with gs thereafter (i.e. dual patterns). Different from dual patterns of gs-Pn relation, the Tr monotonously linearly increased with gs. Furthermore, WUE was almost independent on gs during the first week, while a marked decreasing tendency with gs was found thereafter. At the beginning of the acclimatization, WUE was mainly determined by photosynthetic capacity, while transpiration becomes a main determinant factor for WUE from 7 to 37 days' acclimatization. 展开更多
关键词 Camptotheca acuminate ACCLIMATIZATION Photosynthesis TRANSPIRATION Water use efficiency Relation between stomatal conductance (gs) and net photosynthesis rate (Pn) gs-WUE relation
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Species divergence in seedling leaf traits and tree growth response to nitrogen and phosphorus additions in an evergreen broadleaved forest of subtropical China 被引量:2
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作者 Xuemin Ye Wensheng Bu +3 位作者 Xiaofei Hu Bin Liu Kuan Liang Fusheng Chen 《Journal of Forestry Research》 SCIE CAS CSCD 2023年第1期137-150,共14页
Tree competitiveness generally depends on trait plasticity in response to environmental change.The effects of nitrogen(N)and phosphorus(P)on leaf trait variability by species is poorly understood,especially in China’... Tree competitiveness generally depends on trait plasticity in response to environmental change.The effects of nitrogen(N)and phosphorus(P)on leaf trait variability by species is poorly understood,especially in China’s subtropical forests.This study examined the seedling leaf traits and net primary productivity of all trees>5 cm DBH of two dominant species,Schima superba and Castanopsis carlesii,in an evergreen broadleaved forest fertilized with nitrogen(+N),phosphorus(+P),and nitrogen plus phosphorus(N+P).The effect of N on seedling leaf traits was stronger than P,while fertilization in general was species dependent.Leaf mass per unit area decreased with N for S.superba seedlings but not for C.carlesii.Leaf N,P,and N/P ratios changed with N addition for both species.All four N fractions of carboxylation,bioenergetics,cell wall,and other N metabolites in C.carlesii leaves responded significantly to fertilization,while only the cell wall in S.superb a leaves responded.Other leaf functional traits,including light-saturated photosynthetic rates,water,N,and P use efficiencies,chlorophyll and non structural carbohydrate contents increased with N addition in S.superb a and by P addition in C.carlesii.Canopy closure at the stand-level increased due to N.Litter biomass and relative growth rate of S.superb a was not affected by any treatments,while both for C.carlesii significantly decreased with N+P addition.Collectively,nutrient limitation may vary at a small scale among species in a subtropical forest based on their responses of seedling traits and net primary productivity to fertilization.Seedling traits are not correlated with the net primary productivity of larger trees except for N fractions,because low light conditions induced by fertilization reduces the proportion of N allocated to photosynthesis in seedlings.In addition,acclimation differences of tree species may increase the uncertainty of community succession. 展开更多
关键词 ECOPHYSIOLOGY Fertilization acclimation N fractions Nutrient limitation Photosynthesis relative growth rate
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Growth performance and scale insect infestation of Shorea leprosula in a common garden experimental plot
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作者 Chin Hong Ng Kevin Kit Siong Ng +3 位作者 Soon Leong Lee Rempei Suwa Chai Ting Lee Lee Hong Tnah 《Journal of Forestry Research》 SCIE CAS CSCD 2023年第3期781-792,共12页
Many tree planting programmes have long been initiated to increase forest cover to mitigate the effects of global climate change.Successful planting requires careful planning at the project level,including using suita... Many tree planting programmes have long been initiated to increase forest cover to mitigate the effects of global climate change.Successful planting requires careful planning at the project level,including using suitable species with favourable traits.However,there is a paucity of improvement data for tropical tree species.An experimental common garden of Shorea leprosula was established to study traits related to growth performance which are key factors in planting success.Seedlings of S.leprosula were collected from nine geographical forest reserves.To study the effects of genetic variation,seedlings were planted in a common environment following a randomized complete block design.From performance data collected 2017‒2019,one population showed the highest coefficient for relative height growth,significantly higher than most of the other populations.Interestingly,this population from Beserah also exhibited the lowest coefficient for scale insect infestation.This study provides preliminary results on growth performance and susceptibility to scale insect infestation in S.leprosula and the first common garden experiment site conducted on dipterocarp species.It lays a foundation for future genome-wide studies. 展开更多
关键词 Root collar diameter Height Scale insect relative growth rate DIPTEROCARP
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Factors contributing to the oxygen concentration over the Qinghai-Tibetan Plateau and its contribution rate calculation
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作者 Peijun SHI Ying ZHANG +6 位作者 Yanqiang CHEN Wenquan ZHU Xiaokang HU Heyi YANG Lu JIANG Yonggui MA Haiping TANG 《Science China Earth Sciences》 SCIE EI CAS CSCD 2024年第2期497-509,共13页
A decline in atmospheric oxygen concentration is projected in the 21st century given the background of global warming.The Qinghai-Tibetan Plateau is located at a high altitude,and thus,it faces a hypoxia challenge;how... A decline in atmospheric oxygen concentration is projected in the 21st century given the background of global warming.The Qinghai-Tibetan Plateau is located at a high altitude,and thus,it faces a hypoxia challenge;however,knowledge of the factors contributing to its atmospheric oxygen concentration is still lacking.Here,we conducted joint observations of ecosystem oxygen production and carbon sinks and near-surface atmospheric oxygen concentrations on the Qinghai-Tibetan Plateau and meteorological elements at Beijing Fangshan Station.Using seasonal differences and statistical methods,we calculated the relative contribution rates of vegetation to changes in atmospheric oxygen concentration.Our results indicate that solar radiation,atmospheric humidity,and ecosystem oxygen consumption and production have a significant impact on the atmospheric oxygen concentration,and the impact shows temporal and spatial differences.Vegetation significantly impacts the oxygen concentration,with a contribution rate of 16.7%–24.5%,which is underestimated in existing research.Our findings provide important insights into the factors that influence atmospheric oxygen concentration and highlight the contribution of vegetation.To better understand the oxygen dynamics of the Qinghai-Tibetan Plateau,we recommend further field observations of soil respiration and vegetation photosynthesis to clarify the contributions of carbon storage,carbon sinks and other factors to the near-surface atmospheric oxygen concentration. 展开更多
关键词 Qinghai-Tibetan Plateau Oxygen concentration relative contribution rate Air temperature VEGETATION
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Effects of Sand Burial on the Survival, Growth, and Biomass Allocation in Semi-shrub Hedysarum laeve Seedlings 被引量:14
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作者 张称意 于飞海 董鸣 《Acta Botanica Sinica》 CSCD 2002年第3期337-343,共7页
Hedysarum laeve Maxim. (Leguminosae) is one of the major species used frequently in revegetation of dune_field in the sandlands of the northern part of China by means of aerial sowing. Seedlings of the species after e... Hedysarum laeve Maxim. (Leguminosae) is one of the major species used frequently in revegetation of dune_field in the sandlands of the northern part of China by means of aerial sowing. Seedlings of the species after emergence above the sand surface may be buried in sand to various depths during its establishment in late spring and early summer. A study was made to examine the effects of sand burial at different levels of 0 (control), 33%, 67%, 100% and 133% of their shoot height, on the survivorship, growth, and biomass allocation pattern of H. laeve seedlings (one and two weeks old after emergence). When burial depth was up to 100% of their shoot height, about 70% seedlings died; and the burial at depth of 133% of their shoot height led to death of all seedlings. When seedlings was buried at depth of 33% and 67% of their shoot height, respectively, after six_week growth, their biomass of whole plant, blade, and root and relative growth rate were higher than the unburied counterparts. The seedlings in both 33% and 67% sand burial treatments did not significantly change their biomass allocation pattern comparing with the unburied ones. Furthermore, the number of leaves and shoot height of the seedlings in both 33% and 67% sand burial treatments were not significantly different from those of unburied individuals, respectively. The newly born leaves of the surviving seedlings, in 33%, 67%, and 100% burial treatments, during the period of experiment, were significantly more than those in control. 展开更多
关键词 Hedysarum laeve sandland sand burial SEEDLING GROWTH SURVIVAL biomass allocation relative growth rate
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Relative reactivities of halogen-substituted substrates (R-Br,R-C1) toward the halophilic attack by a carbanion
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作者 傅伟敏 张晓军 蒋锡夔 《Science China Chemistry》 SCIE EI CAS 2001年第4期337-343,共7页
Relative reactivities of bromine-substituted substrates (R-Br) or chlorine-substituted substrates (R-CI) toward bromophilic or chlorophilic attack by a carbanion have been evaluated by the intermolecular competition k... Relative reactivities of bromine-substituted substrates (R-Br) or chlorine-substituted substrates (R-CI) toward bromophilic or chlorophilic attack by a carbanion have been evaluated by the intermolecular competition kinetics. Relative reactivity orders are CF3CFBr2 >CF3CBr3≥CBr4 > CHBr3 > CF3CFBrCF2Br > CF2Br2 > BrCF2CF2Br > BrCH2CO2Et≥ BrCF2CFHBr > CH2Br2 > BrCH2CH2Br, and CI3CNO2 > CI3CCN > CI3CCOPh > cyclo-C5CI6> CI3CCOCI > CCI3CF2CI > CCI3CF3 ≥ CCI4 > CCI3CCI3 ≥ CCI3(CF2)2CI > CI3CCOCCI3 > CCI3(CF2)6CI > CI3CCO2Et > CI3CF > CI3CPh>CI3CCH2O2CCH3. 展开更多
关键词 relative reactivities halogen-substituted substrates relative rates of halophilic attacks intermolecular competition kinetics
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DFT Study on Some Properties of Polybrominated Phenoxathiin 10-Oxides
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作者 曲瑞娟 石佳奇 +2 位作者 程润秋 杨曦 王遵尧 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2011年第10期1501-1508,共8页
With the B3LYP calculation method of density functional theory(DFT)and the 6-31G* basis set,full optimization calculation was made for phenoxathiin10-oxide(PTO)and 135 polybromine phenoxathiin 10-oxides(PBPTOs)... With the B3LYP calculation method of density functional theory(DFT)and the 6-31G* basis set,full optimization calculation was made for phenoxathiin10-oxide(PTO)and 135 polybromine phenoxathiin 10-oxides(PBPTOs)with the Gaussian 03 program and molar heat capacity in constant volume(CVθ)value of each molecule in the standard state was obtained.The relation between CVθ and the substitution position and number of bromine atom(NPBS)was studied,and the results indicated good correlation(R2 = 1.000)between CVθ and NPBS of PBPTO compounds.Based on the output file of Gaussian 03 program,molar heat capacity at constant pressure(Cp,m)of PBPTO compounds from 200 to 1,000 K was calculated with the statistical thermodynamics program,and the correlation equation between Cp,m and temperature(T,T-1 and T-2)was obtained with the least-squares method,and the correlation coefficient of the correlation equation(R2)was 1.000.In addition,based on the partition function of each molecule calculated by vibration analysis,the relative rate constant of formation of each molecule was calculated. 展开更多
关键词 PBPTOs substitution position and number of bromine atom(NPBS) molar heat capacity in constant volume(CVθ) molar heat capacity at constant pressure(Cp m) relative rate constant
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Regeneration characteristics of gaps and their effect on Abies fargesii forests in the Shennongjia National Nature Reserve,China 被引量:2
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作者 FU Chan-juan LIU Yan-hong XIONG Wen-juan 《Forestry Studies in China》 CAS 2010年第4期206-212,共7页
Abiesfargesii is an evergreen tree species of the Pinaceae family, one of the most important cultivated timber species, endemic to China. It is of great importance for the maintenance of vegetation landscape and the p... Abiesfargesii is an evergreen tree species of the Pinaceae family, one of the most important cultivated timber species, endemic to China. It is of great importance for the maintenance of vegetation landscape and the preservation of endangered animal species. Community regeneration of forest gaps and their effect on A. fargesii forests in the Shennongjia National Nature Reserve were studied based on two-year field survey data. The results show that 1) forest gap regeneration is an important approach for the regeneration of A. fargesii communities; regeneration characteristics in the gaps of the broad-leaved species Betula albo-sinensis Burk. and the shade-tolerant species A. fargesii differed from those of understory species. 2) A. fargesii is most predominant in early gap regeneration but, over time, is gradually replaced by other species. Seedlings less than three years old accounted for 45.7% of all seedlings and only 6.3% of saplings older than seven years. 3) In terms of height and basal diameter in different sized gaps, size of seedlings showed the following trend: medium 〉 small 〉 large 〉 understory; the relative growth rate appeared in the same order. 4) The size of seedlings did not appear different between within-gap positions in medium and small gaps, but the tallest seedlings grew in the south of the large gaps and declined towards the center and north edges. 5) Principal component analysis suggests that the most important factors for the growth and distribution ofA. fargesii seedlings decreased in order of gap size, slope direction, gap microenvironment and tree-shrub-grass cover. 展开更多
关键词 Abiesfargesii REGENERATION GAP relative growth rate
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Morphology Analysis of Nickel-boron/diamond Eleetroless Deposition 被引量:1
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作者 WANG Lin ZHU Xuanmin +1 位作者 ZHOU Jian OUYANG Shixi 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2008年第2期169-172,共4页
The influences of mass concentration of nickel chloride hexahydrate, sodium borohydride, ethylenediamine, pH value, bath temperature on deposition rate were studied with orthogonal experiments by a series of pre-treat... The influences of mass concentration of nickel chloride hexahydrate, sodium borohydride, ethylenediamine, pH value, bath temperature on deposition rate were studied with orthogonal experiments by a series of pre-treatments on micro-diamond particle, and the optimized parameters were obtained. Both the morphology and the composition of original diamond and the diamond with Ni-B coating were analyzed by SEM and XRD respectively. The SEM image shows that the spherical Ni-B particle is coated upon diamond. XRD pattern shows that the coating compositions are Ni and Ni2B. 展开更多
关键词 DIAMOND Ni-B orthogonal experiment relative deposition rate
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Effect of NaNO_3 Concentrations on the Growth and Fatty Acid Compositions of Nitzschia closterium and Chaetoceros gracilis* 被引量:1
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作者 梁英 麦康森 孙世春 《Marine Science Bulletin》 CAS 2003年第1期69-74,共6页
Fatty acid compositions of two strains of marine diatoms Nitzschia closterium ( MACC B222 ) and Chaetoceros gracilis ( MACC B13 ) have been examined. The microalgae have been grown at different initial NaNO3 concentr... Fatty acid compositions of two strains of marine diatoms Nitzschia closterium ( MACC B222 ) and Chaetoceros gracilis ( MACC B13 ) have been examined. The microalgae have been grown at different initial NaNO3 concentrations ( 75, 375, 750, 1 125, 1 500, 1 875 mg/L ) and harvested at the late exponential phase. The results by one factor analysis of variance show that the NaNO3 concentrations have no significant influence on the relative growth rate of two strains of marine diatoms; the influence of NaNO3 concentrations on the fatty acids differs from species to species. The major fatty acids of two --diatom strains are 14:0, 16:0, 16:1n7 and 20:5n3 ( EPA ) , B13 also has high percentage -of 20:4n6 ( 6.0 ~ 9.1% ). 展开更多
关键词 Nitzschia closterium Chaetoceros gracilis NaNO3 relative growth rate fatty acid
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Amniocentesis: A contemporary review 被引量:1
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作者 Katherine Ann Connolly Keith Arnold Eddleman 《World Journal of Obstetrics and Gynecology》 2016年第1期58-65,共8页
Amniocentesis is an essential tool in obstetrics. Invasive testing remains the only modality for diagnostic genetic testing and the only way to provide comprehensive test-ing for chromosomal abnormalities. Despite inc... Amniocentesis is an essential tool in obstetrics. Invasive testing remains the only modality for diagnostic genetic testing and the only way to provide comprehensive test-ing for chromosomal abnormalities. Despite increasing use of cell free fetal deoxyribonucleic acid (DNA) testing, amniocentesis should still be offered to all women who desire more complete and accurate genetic testing. Counseling patients on the limitations of screening tests is of the upmost importance and amniocentesis should continue to be recommended to confrm positive results from cell free fetal DNA testing or in the case of failed cell free fetal DNA test. As cell free fetal DNA screening has not adequately been studied in multiple gestations, its use is not recommended in this population and invasive testing should be offered. Amniocentesis is also very useful in providing additional information in settings other than genetic testing the second and third trimester. If intraamniotic infection is suspected, but the clinical fndings are not enough to guide manage-ment, amniocentesis can provide testing that can both immediately clarify the picture (interleukin-6, gram stain, glucose levels) and finally confirm the presence of infection (culture). It can also be used to detect the presence of intrauterine viral infections. Additionally, amniocentesis may be used to test for markers of fetal lung maturity. The American Congress of Obstetricians and Gynecologists recommends that amniocentesis for this indication not be used in cases where late preterm delivery is indicated. It may be useful in guiding decision-making, however , when late preterm delivery is indicated, but when exact timing is unclear. Regardless of the indication, amniocentesis appears to be a relatively low risk procedure with minimal risk to the patient. Additional randomized controlled trials are not likely, as they are not feasible to due extremely high number of participants that would be needed to detect a difference in loss rates. Based on current literature, however, the risk of pregnancy loss from second trime-ster amniocentesis is low in both singleton and twin gestations. We counsel patients that technique has changed since the original studies in the 1970s and feel comfortable quoting a loss rate of 1/500-1/1000 based on contemporary data. 展开更多
关键词 AMNIOCENTESIS Prenatal diagnosis Invasive genetic testing Procedure related loss rates Cell free fetal DNA testing Fetal lung maturity Intraamniotic infection
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Phytoremediation of Rocky Slope Surfaces: Selection and Growth of Pioneer Climbing Plants
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作者 WANG Zhong-Qiang WU Liang-Huan +1 位作者 S. ANIMESH ZHU Yuan-Hong 《Pedosphere》 SCIE CAS CSCD 2009年第4期541-544,共4页
INTRODUCTION As a result of the massive construction following rapid economic growth in China, extraction of building materials from mountain resources has left behind many quarries. Those quarries usually have rocky ... INTRODUCTION As a result of the massive construction following rapid economic growth in China, extraction of building materials from mountain resources has left behind many quarries. Those quarries usually have rocky surfaces and steep slopes. The existence of rocky slopes is not only a safety hazard but also increases soil erosion and affects landscape aesthetics. Natural restoration of vegetation on rocky slope surfaces is a very slow process, which might require hundreds of years, and is not considered an acceptable restoration strategy (Cullen et al., 1998). Phytoremediation methods have been widely considered as a better option for vegetation establishment on rocky slope surfaces (Muzzi et al., 1997). 展开更多
关键词 relative growth rate survival rate vegetation restoration
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Temperature responsiveness of seedlings maximum relative growth rate in three Mediterranean Cistus species
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作者 Giacomo Puglielli Alessandra Spoletini +1 位作者 Giuseppe Fabrini Loretta Gratani 《Journal of Plant Ecology》 SCIE CSCD 2017年第2期331-339,共9页
Aims Relative growth rate(RGR)is an indicator of the extent to which a species is using its photosynthates for growth and it is affected by environmental factors,including temperature.Nevertheless,most of plant growth... Aims Relative growth rate(RGR)is an indicator of the extent to which a species is using its photosynthates for growth and it is affected by environmental factors,including temperature.Nevertheless,most of plant growth studies have been carried out at a single growth temperature or at different temperature treatments,resulting in the lack of information on the relationship between RGR and chang-ing mean daily air temperature.We analyzed the temporal changes in RGR during early growth stages in three Cistus species grown outdoor in a common garden from seeds of different provenances.Moreover,we wanted to define the relationship between daily changes in RGR and mean daily air temperature for the considered provenances.The hypothesis that intra-specific temporal variations in RGR can reflect differences in the behavior to maximize RGR(RGRmax)in response to temperature was tested.Methods Seedlings of C.salvifolius,C.monspeliensis and C.creticus subsp.eriocephalus were grown outdoor in the experimental garden of the Sapienza University of Rome under a Mediterranean climate.We analyzed early growth with non-linear growth models and calcu-lated function-derived RGRs as the derivative with respect to time of the parameterized functions used to predict height divided by cur-rent height.The relationships between function-derived RGRs and mean daily air temperature were analyzed by linear and non-linear models,which were ranked according to their standard errors and correlation coefficients.The temperature dependency of RGRmax per each provenance was evaluated through the relationship between RGRmax and the coefficients of the best regression model obtained.Important Findings A parameter that could summarize the temperature dependency of RGR up to RGRmax during the early growth stages for the selected provenances was defined.This allowed us to highlight that a greater RGR temperature responsiveness was related to a delay in the time to reach RGRmax independently by the species.Nevertheless,a greater temperature sensitivity of RGR lead to a reduced maximum height which reflects a negative trade-off between the length of the developmental phases and the extent of RGR temperature respon-siveness.Thus,variations in temperature responsiveness of RGR up to RGRmax have a significant role in shaping the early growth for the investigated species.Our findings quantitatively define provenance dependent strategies by which the selected species cope with daily air temperature variations during early growth. 展开更多
关键词 early growth stage non-linear growth models function-derived relative growth rate local adaptation
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Comparison on Inhibitory Effects of Fifteen Kinds of Traditional Chinese Medicine on Neospora canium
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作者 KONG Lin 《Animal Husbandry and Feed Science》 CAS 2012年第1期31-33,共3页
Abstract [Objective] The study was aimed to screen some Chinese medicines with good inhibitory effects on Neospora [Method] The crude extracts of the tested Chinese medicines were added to the Vero cells that were in... Abstract [Objective] The study was aimed to screen some Chinese medicines with good inhibitory effects on Neospora [Method] The crude extracts of the tested Chinese medicines were added to the Vero cells that were infected by Neospora canium. Then, cell growth was ob- served. The death rate and relative suppression rate of Neospora canium were determined by trypan blue staining. [ Result] The extracts of Scutel- laria baicalensis, Stemona japonica, Rhizoma gastrodiae, Coptis chinensis, Areca catechu and Brucea javanica had better inhibitory and killing effects on Neospora canium in vitro. [ Conclusion ] The study serves the treatment of neosporosis in clinic. 展开更多
关键词 Neospora canium Chinese medicine relative suppression rate Death rate
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Carbon Dioxide Concentrations and Light Levels on Growth and Mineral Nutrition of Juvenile Cacao Genotypes
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作者 Virupax C. Baligar Marshall K. Elson +3 位作者 Alex-Alan F. Almeida Quintino R. de Araujo Dario Ahnert Zhenli He 《American Journal of Plant Sciences》 2021年第5期818-839,共22页
In many countries cacao (</span><i><span style="font-family:Verdana;">Theobroma cacao</span></i><span style="font-family:Verdana;"> L.) is invariably grown as an... In many countries cacao (</span><i><span style="font-family:Verdana;">Theobroma cacao</span></i><span style="font-family:Verdana;"> L.) is invariably grown as an understory crop in agroforestry types of cropping systems and subjected to low levels photosynthetic photon flux density (PPFD) due to presence of large number of upper story shade trees with poorly managed canopy structure. In recent years carbon dioxide concentration in the atmosphere is steadily increasing and it is unclear what impact this will have on performance of cacao grown under shade of upper story shade trees. A climatically controlled greenhouse experiment was undertaken to evaluate the effects of ambient and elevated carbon dioxide (400 and 700 μmol&middot;mol</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">) and three levels of PPFD (100, 200, and 400 μmol&middot;m</span><sup><span style="font-family:Verdana;">-2</span></sup><span style="font-family:Verdana;">&middot;s</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">) on growth, and macro- and micronutrient use efficiency of three genetically contrasting cacao genotypes (CCN 51, VB 1117 and NO 81). Intraspecific variations were observed in cacao genotypes for growth parameters at ambient to elevated carbon dioxide and low to adequate levels of PPFD. With the exceptions of total root length and leaf area, irrespective of carbon dioxide and PPFD levels, all three genotypes showed significant differences in all the growth parameters. For all the cacao genotypes, increasing PPFD from 100 to 400 μmol&middot;m</span><sup><span style="font-family:Verdana;">-2</span></sup><span style="font-family:Verdana;">&middot;s</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"> and carbon dioxide from 400 to 700 μmol&middot;mol</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"> increased overall growth parameters such as leaf, shoot and root biomass accumulation, stem height, leaf area, relative growth rate and net assimilation rate. Irrespective of carbon dioxide and PPFD, invariably genotypes differed significantly in macro-micronutrient uptake parameters such as concentration, uptake, influx, transport and use efficiency. With few exceptions, raising PPFD from 100 to 400 μmol&middot;m</span><sup><span style="font-family:Verdana;">-2</span></sup><span style="font-family:Verdana;">&middot;s</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"> and carbon dioxide from 400 to 700 μmol&middot;mol</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"> increased nutrient use efficiency for all the cacao genotypes. Elevated carbon dioxide and adequate PPFD are benefi</span><span style="font-family:Verdana;">cial in improving cacao growth and mineral nutrient uptake and use efficiency. 展开更多
关键词 relative Growth rate Net Assimilation rate Mineral Nutrient Influx and Transport Mineral Nutrient Uptake Efficiency
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