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A PRELIMINARY STUDY ON THE MODEL OF DEVELOPMENTAL RATE OF RICE
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作者 蓝鸿第 《Chinese Science Bulletin》 SCIE EI CAS 1982年第10期1103-1110,共8页
The relationship between the developmental rate of crops and meteorological factors is not only a fundamental theory of agrometeorology, but also the foundation of agroclimatic division and agrometeorological forecast... The relationship between the developmental rate of crops and meteorological factors is not only a fundamental theory of agrometeorology, but also the foundation of agroclimatic division and agrometeorological forecasting as well. Therefore, some studies have been made on this by scientific workers at home and abroad. This paper provides a further approach to this subject on the basis of comparatively integral data. 展开更多
关键词 METEOROLOGICAL forecasting rate developmental MATURITY HEADING CROPS remarkable DATES yellow
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Theory of Capital,Investment and Exchange Rate:A New Developmentalist Equation
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作者 Cristina Helena Pintode Mello 《Chinese Business Review》 2017年第4期159-169,共11页
The article deals with the relationship between the decision to invest and the exchange rate. The literature relates investment at interest rate. An increase in the interest rate would reduce the investment expendit... The article deals with the relationship between the decision to invest and the exchange rate. The literature relates investment at interest rate. An increase in the interest rate would reduce the investment expenditure. Jorgenson’s equation uses the flexible accelerator model, taxation, and the cost of capital to explain and predict the amount of investment in machinery and equipment. The relationship between the exchange rate and the investment appears in the literature as a direct relation. An appreciated exchange rate allows the importation of cheaper machinery and equipment and increases productive investments. This paper proposes a modified equation in which the appreciated exchange rate inhibits productive investments by reducing the expectation of profit, either because the domestic market becomes more competitive or because exports decrease. It still incorporates in the model of Jorgenson the idea that the unit cost of labor is the relevant variable to explain the choice of investing, assuming a function of production of fixed coefficients. 展开更多
关键词 INVESTMENT exchange rate economic development decision EXPECTATION PROFIT
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Incubation temperature induced developmental plasticity of cold responsive physiological phenotypes in Japanese Quails
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作者 Yingxin Kou Rongmiao Zhang +3 位作者 Xiaoqian Li Na Zhu Yihang Huang Shuping Zhang 《Avian Research》 SCIE CSCD 2024年第3期385-394,共10页
Embryonic development is a critical period for phenotype formation.Environmental variation during embryonic development can induce changes in postnatal phenotypes of animals.The thyroxine secretion and aerobic metabol... Embryonic development is a critical period for phenotype formation.Environmental variation during embryonic development can induce changes in postnatal phenotypes of animals.The thyroxine secretion and aerobic metabolic activity of small birds are important phenotypes closely related to their winter survival.In the context of climate change,it is necessary to determine whether temperature variation during incubation in birds leads to developmental plasticity of these cold responsive phenotypes.We incubated Japanese Quail(Coturnix japonica)eggs at 36.8℃,37.8℃,and 38.8℃,and raised the chicks to 35-day old at 22℃with same raising conditions,then all the quails were exposed to gradually temperature dropping environment(from 15℃to 0℃).After cold treatment,serum T3 level,resting metabolic rate,skeletal muscle and liver metabolomes of the birds were measured.The serum T3 levels were significantly lower in the 38.8℃group and significantly higher in the 36.8℃group compared to the 37.8℃group.The metabolic rate in the 38.8℃group was significantly lower compared to the 37.8℃group.Compared with the 37.8℃group,metabolites involved in the tricarboxylic acid cycle in the liver were significantly lower in the 38.8℃group,and metabolites related to lipid oxidation metabolism and fatty acid biosynthesis were significantly lower in the skeletal muscles in the 38.8℃group but significantly higher in the 36.8℃group.These results indicate that incubation temperature variation can lead to developmental plasticity in cold responsive physiological phenotypes.Higher incubation temperature may impair the capacity of birds coping with cold challenge. 展开更多
关键词 Cold response developmental plasticity Incubation temperature Metabolic rate Metabolomes Precocial bird THYROXIN
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Relationship between energy dissipation rate and channel morphology in the development of the model braided channel 被引量:2
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作者 ZHANG Ou-yang, JIN De-sheng, CHEN Hao, GUO Qing-wu (Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China) 《Journal of Geographical Sciences》 SCIE CSCD 2001年第3期291-296,共6页
A certain pattern of channel is the product of its self-adjustment under given boundary, discharge and sediment conditions. Based upon the principle of process-response model, an experimental study with 18 runs is car... A certain pattern of channel is the product of its self-adjustment under given boundary, discharge and sediment conditions. Based upon the principle of process-response model, an experimental study with 18 runs is carried out in LESRC. This paper is focused on the variation of the energy dissipation versus the channel morphology during and after the bedmaking process of braided channel. The results show that there exists a good empirical relationship between the energy dissipation rate and channel morphology. According to this relationship and the theory of minimum rate of energy dissipation, the authors explain the metamorphosis of the model channel with the development of the braided river. 展开更多
关键词 energy dissipation rate channel morphology braided channel development experimental study
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Effect of different stretching strategies on the kinetics of vertical jumping in female volleyball athletes 被引量:2
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作者 Nicholas T. Kruse Marcus W. Barr +2 位作者 Roger M. Gilders Michael R. Kushnick Sharon R. Rana 《Journal of Sport and Health Science》 SCIE 2015年第4期364-370,共7页
Purpose: The present study aimed to examine the effect of static stretching (SS) and a sport-specific dynamic stretching (DS) session at two specific post-stretch time intervals in highly trained female athletes ... Purpose: The present study aimed to examine the effect of static stretching (SS) and a sport-specific dynamic stretching (DS) session at two specific post-stretch time intervals in highly trained female athletes (age 19.90 ± 1.60 years; height 1.80 ±0.06 m; mass 76.87 ± 9.95 kg) on kinetic parameters of peak force, time-to-takeoff, and rate of force development. Methods: The data were collected over 3 days (randomized within subject design with control session). Following each stretch session (SS vs. DS vs. control) of equal duration (7 min total: 30 s per targeted muscle group) participants performed countermovement jumping on a force platform at 1 and 15 rain after stretching. Results: The DS session significantly improved upon kinetic variables of rate of force development, peak force, and time-to-takeoffrelative to SS at 1 min after stretching. No significant effect was found at 15 min. Conclusion: Together these findings suggest that when training and competing to jump quickly and maximally the female athlete should incorporate DS instead of SS as part of their pre-competition warm-up, but conduct performance within 15 min of their warm-up to elicit maximal gains 展开更多
关键词 Dynamic stretching Female athletes rate of force development Static stretching Time-to-takeoff
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Impacts of climate change on development rate and production of corn in the northeastern China 被引量:1
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作者 Guo Jianping, Gao Suhua Pan YaruChinese Academy of Meteorological Sciences, Beijing 100081, China 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 1993年第2期201-208,共8页
In this paper, the impacts of climate change on development rate and production of corn in the northeastern China are discussed. The results show that the higher the temperature is, the faster the development rate wil... In this paper, the impacts of climate change on development rate and production of corn in the northeastern China are discussed. The results show that the higher the temperature is, the faster the development rate will be. And the more the precipitation is, the slower the development rate will be. Of which, air temperature is the controlling factor of corn development rate. The influences of development rate on corn yield are remarkable. The impacts of development rate on production in first and last periods are great, and small in the middle two periods. The development rate is positive by relate with corn production from sowing to emergence stage and negative during other periods. So, it is very important to arrange a suitable sowing time for com cultivating in the northeastern China. 展开更多
关键词 climate change development rate corn.
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Development of River Rating Curves for Simple to Complex Hydraulic Structure Based on Calibrated HEC-RAS Hydraulic Model, in Kwale, Coastal Kenya 被引量:1
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作者 Calvince Wara Mike Thomas +1 位作者 Suleiman Mwakurya Jacob Katuva 《Journal of Water Resource and Protection》 2019年第4期468-490,共23页
Accurate and reliable river flow information is critical to planning and management for sustainable water resources utilization. Most of engineering activities related to hydrologic designs, flood, drought, reservoirs... Accurate and reliable river flow information is critical to planning and management for sustainable water resources utilization. Most of engineering activities related to hydrologic designs, flood, drought, reservoirs and their operations are heavily dependent on the river flow information derived from river rating curve. The rating curve for a given river section is normally developed from a set of direct stage-discharge measurements for different periods. This involves considerable labour, risk and resources, and presupposes a complex and extensive measuring survey. Extrapolating the rating curve beyond the measured range, as common in many cases, is fraught with errors and uncertainties, due to the complex hydraulic behaviour of the surface water profile in transition from section, channel, downstream and flood plain controls which are often poorly understood with direct measurements. Hydraulic modeling has recently emerged as one of the more promising methods to efficiently develop accurate rating curves for a river section with simple or complex hydraulic structures and conditions. This paper explores the use of a Hydraulic Engineering Center-River Analysis System (HEC-RAS) model to review and develop river rating curves for three hydrometric stations on two rivers in Kwale, coastal Kenya. The HEC-RAS models were set up based on topographical (cross section and longitudinal) survey data for the reaches and engineering drawings for the hydraulic structures commonly used as section controls for flow measurement. The model was calibrated under unsteady state conditions against measured stage-discharge data which were captured using a Velocity Current Meter (Valeport) and an Acoustic Doppler Current Profiler (ADCP) for both low and high flow. The rating curves were extracted from model results and the uncertainty associated with each rating curve analyzed. The results obtained by the HEC-RAS model were satisfactory and deemed acceptable for predicting discharge across the stage range at each river section. 展开更多
关键词 RIVER RATING Curve DEVELOPMENT Hydraulic Simulation of STAGE-DISCHARGE Relationship HEC-RAS Model Calibration
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Strategic Considerations on Development of WiMAX and Its Relationship with 3G and 4G 被引量:1
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作者 Chen Ruming (Communications Science and Technology Commission, Ministry of Information Industry, Beijing 100037, China) 《ZTE Communications》 2005年第1期48-50,53,共4页
The paper states the characteristics and basic market positioning of WiMAX. It should be noted that WiMax is a new generation WMAN (Wideband MAN) broadband wireless access standard with good forward extensibility. It ... The paper states the characteristics and basic market positioning of WiMAX. It should be noted that WiMax is a new generation WMAN (Wideband MAN) broadband wireless access standard with good forward extensibility. It is emphasized that the basic market positioning of WiMAX should be nothing but WMAN applications. It is predicted that the applications of WiMax would face severe challenges mainly due to its high cost, at least at the initial stage. Finally the paper gives all-around analysis on the relationship between Wi-Fi, WiMAX, WBMA, 3G, 3G+ and 4G. 展开更多
关键词 WIMAX rate Strategic Considerations on Development of WiMAX and Its Relationship with 3G and 4G
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Development rate of Labidocera euchaeta Giesbrecht in Xiamen Harbor
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作者 Lin Senjie and Li Song Department of Oceanography, Xiamen University, Xiamen, China 《Acta Oceanologica Sinica》 SCIE CAS CSCD 1990年第3期439-447,共9页
-The development rate of Labidocera euchaeta Giesbrecht in the Xiamen Harbor was studied in laboratory. The results showed that the development times of egg and larval stages ( D ) were significantly correlated with t... -The development rate of Labidocera euchaeta Giesbrecht in the Xiamen Harbor was studied in laboratory. The results showed that the development times of egg and larval stages ( D ) were significantly correlated with temperature ( T ), following the Belehradek function, D = α( T -7. 5)-1.0634. The development time from egg to larval stages and adult, as well as generation time can be predicted from the equation for egg development ( α=411/24) by appropriately multipling the constant (α) with a proportion. The development was not isochronal over the whole larval period. Durations of naupliar stages were short and quasi-isochronal, which favored their non-feeding development. In contrast, durations of copepodid stages (C) were long. CV had the longest duration followed by CI, both of which are considered as the critical stages in the larval development. The acclimation effect of the seasonal temperature on the development rate was also observed. 展开更多
关键词 TH LAB Development rate of Labidocera euchaeta Giesbrecht in Xiamen Harbor rate
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Effect of Strain Rate on Compression Behavior of Vinyl Ester Resin Casting
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作者 XIONG Tao YANG Bin XIONG Jie XU Xian-jian ZHOU Kai MAO Ming-zhong 《材料工程》 EI CAS CSCD 北大核心 2006年第5期63-67,72,共6页
Quasi-static and high strain rate compressive experiments on vinyl ester casting were carried out by means of MTS (Material Test System) and Hopkinson bar. The behaviors of the compressed unstable and fracture of the ... Quasi-static and high strain rate compressive experiments on vinyl ester casting were carried out by means of MTS (Material Test System) and Hopkinson bar. The behaviors of the compressed unstable and fracture of the resin casting at different strain rates were investigated.The results indicate that the response behavior of the resin casting is controlled by different mechanisms at different strain rate, and some mechanical properties of vinyl ester casting are rate-dependent: the casting are destroyed in toughness model under strain rate 3.3×10 -4~6.6×10 -3/s, while the casting are destroyed in brittleness model under strain rate 950~5800/s. The yield stress, yield strain energy density are all increased with the increasing strain rates at quasi-static as well as at high strain rates. What is interesting is that the yield strain decreased with the strain rates increasing at quasi-static while increased at high strain rates. It is considered that the casting occurred forcing high elastic deformation at high strain rates. The damage of the specimens is mainly controlled by axial stress before unstable deformation, while mainly controlled by shear stress after unstable deformation, and then developed to fracture finally. This progress is rate-dependent: the development of the cracks inside the castings increased with the strain rate increasing. 展开更多
关键词 vinyl ester resin QUASI-STATIC high strain rate strain rate response and crack development
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Effects of Bovine Embryos at Different Developmental Stages on Bisection Effect
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作者 Guizhi TONG Yongsheng HAN +3 位作者 Hongbao WANG Xintao LI Weixia WANG Xueying SONG 《Agricultural Biotechnology》 CAS 2021年第5期60-62,共3页
[Objectives]This study was conducted to explore the effects of embryos at different developmental stages on the bisection effect of embryos,improve the efficiency of bovine embryo bisection,and facilitate the applicat... [Objectives]This study was conducted to explore the effects of embryos at different developmental stages on the bisection effect of embryos,improve the efficiency of bovine embryo bisection,and facilitate the application of embryo bisection technology in cattle breeding.[Methods]The effects of two different bisection solutions on the bisection of morulae and blastocysts in vitro were explored.The morulae and blastocysts produced in vitro from cattle that developed to the 6th to 8th d were bisected by hands,and demi-embryos were cultured in vitro.Their development was observed.[Results]Morulae were bisected in PBS solution and PBS+0.2 mol/L sucrose,and the success rates of bisection were 50%and 95.2%,respectively.The success rate of bisecting morulae in PBS+0.2 mol/L sucrose was significantly higher than that in PBS(P<0.05),while the development rate of the bisected demi-embryos had no significant difference between the two(53.3%,52.4%)(P>0.05).The success rates of blastocyst bisection in PBS solution and PBS+0.2 mol/L sucrose were 51.6%and 95.1%,respectively.The success rate of blastocyst bisection in PBS+0.2 mol/L sucrose was significantly higher than that in PBS(P<0.05),while the development rate of the bisected demi-embryos had no significant difference between the two(50.0%,56.4%)(P>0.05).[Conclusions]There were no significant differences between the success rates of bisecting bovine morulae and blastocysts in PBS+0.2 mol/L sucrose,which were both significantly better than those in pure PBS bisection solution,proving that PBS+0.2 mol/L sucrose bisection solution is suitable for bovine embryo bisection. 展开更多
关键词 CATTLE Embryo division Success rate Development rate MORULA BLASTOCYST
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Spatiotemporal variations in the organic carbon accumulation rate in mangrove sediments from the Yingluo Bay,China,since 1900
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作者 Yao Zhang Xianwei Meng +4 位作者 PengXia Jun Zhang Dahai Liu Zhen Li Wanzhu Wang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2021年第8期65-77,共13页
Mangroves can not only provide multiple ecosystem service functions,but are also efficient carbon producers,capturers,and sinks.The estimation of the organic carbon accumulation rate(OCAR)in mangrove sediments is fund... Mangroves can not only provide multiple ecosystem service functions,but are also efficient carbon producers,capturers,and sinks.The estimation of the organic carbon accumulation rate(OCAR)in mangrove sediments is fundamental for elucidating the role of mangroves in the global carbon budget.In particular,understanding the past changes in the OCAR in mangrove sediments is vital for predicting the future role of mangroves in the rapidly changing environment.In this study,three dated sediment cores from interior and fringe of mangroves in the Yingluo Bay,China,were used to reconstruct the spatiotemporal variations of the calculated OCAR since 1900 in this area.The increasing OCAR in the mangrove interior was attributed to mangrove flourishment induced by climate change characterized by the rising temperature.However,in the mangrove fringe,the strengthening hydrodynamic conditions under the sea level rise were responsible for the decreasing OCAR,particularly after the1940 s.Furthermore,the duration of inundation by seawater was the primary factors controlling the spatial variability of the OCAR from the mangrove fringe to interior,while the strengthened hydrodynamic conditions after the 1940 s broke this original pattern. 展开更多
关键词 spatiotemporal variation organic carbon accumulation rate organic carbon source mangrove development TEMPERATURE hydrologic conditions
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Chinese medicine practitioner turnover rate and the development of Chinese medicine in Hong Kong,China
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作者 Ka-Kit Chua Vivien Lau +1 位作者 Wing-Yan Lee Chun-Pong Lam 《Journal of Traditional Chinese Medical Sciences》 2021年第2期145-149,共5页
Objective:To establish that the Hong Kong Special Administrative Region(HKSAR)government is actively promoting Chinese medicine(CM)and to examine turnover rate of Chinese medicine practitioners(CMPs)in Hong Kong,China... Objective:To establish that the Hong Kong Special Administrative Region(HKSAR)government is actively promoting Chinese medicine(CM)and to examine turnover rate of Chinese medicine practitioners(CMPs)in Hong Kong,China in light of this governmental push.Methods:This study covered two major areas:reviewing CM development in Hong Kong,and assessing the turnover rate of CMPs in Hong Kong.The first part of the paper is a historical review.The investigation of turnover rate had two sections.Section 1,quantitative method,involved online questionnaires;Section 2,qualitative method comprised interviews with CMPs from different types of CM clinics to ascertain the reasons for the turnover among CMPs.Results:A total of 123 online questionnaires were received in Section 1(55 from male CMPs;66 from female CMPs;2 respondents were unwilling to disclose their sex).The proportion of CMPs who had resigned in 2018e19 was 22.8%(28),of whom 5.7%(7)had resigned twice in one year.The rates of resignation in 3 years and 5 years were up to 40.7%(50)and 56.9%(70),respectively.Six CMPs were interviewed in Section 2.Young CMPs were more likely to resign than seniors.The large gap between actual salary and expectations appeared to be the main reason for the high rate of resignation.Conclusion:HKSAR government keenly desires to promote CM in Hong Kong,however,high turnover rate of CMPs was detected even under this positive governmental support.There is an urgent need to conduct a more representative study of the reasons for the inclination of CMPs in Hong Kong.The study highlights an important issue in CM development,and these results should remind different stakeholders in the CM industry and the government that CMPs need better career prospects and support in various areas. 展开更多
关键词 Chinese medicine development Chinese Medicine Turnover rate Hong Kong SAR Career prospect SALARY
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National Breast Cancer Mortality and Incidence Rates According to the Human Development Index: An Ecological Study
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作者 Salman Khazaei Shahab Rezaeian +4 位作者 Zaher Khazaei Leila Molaeipoor Shahrzad Nematollahi Parvaneh Lak Somayeh Khazaei 《Advances in Breast Cancer Research》 2016年第1期30-36,共7页
Background: This study aimed to identify the role of human development index (HDI) in the incidence and mortality rates of breast cancer (BC) worldwide. Methods: Data on the age-standardized incidence and mortality ra... Background: This study aimed to identify the role of human development index (HDI) in the incidence and mortality rates of breast cancer (BC) worldwide. Methods: Data on the age-standardized incidence and mortality rates of BC for 184 countries were obtained from the GLOBOCAN. Data about the HDI and other indices were obtained from the World Bank Report 2013. Linear regression model was used for assessment the effect of HDI on BC occurrence rates. Results: In 2012, BCs were estimated to have affected a total of 1,671,149 individuals (crude rate: 47.8 per 100,000 individuals), and caused 521,907 deaths worldwide (crude rate: 14.7 per 100,000 individuals). Nearly half of total female BC cases (46.3%) with the highest risk of incidence (age-standardized Rate (ASR): 128 per 100,000) had occurred in very high HDI regions. The most proportion of the mortality burden was in low HDI and medium HDI areas. Linear regression analyses showed a direct significant correlation between the incidence of BC and HDI at the global level (B = 104.5, P < 0.001). The mortality rate of BC was not significantly associated with HDI (B = 3.26, P = 0.160). Conclusion: Our study showed that the burden of female BC is enormous in very high HDI and low HID regions. Targeted interventions have the ability to reduce this number significantly through resource-dependent interventions. Moreover, further reductions in mortality could be brought about by increasing access to curative treatment for patients with BC. 展开更多
关键词 Breast Cancer Human Development Index INCIDENCE Age-Standardized Incidence and Mortality rates
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Linear Mixed Model Analysis of Worldwide Longitudinal Infant Mortality Rate Data and Association with Human Development Index
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作者 Serpil Aktas 《Journal of Mathematics and System Science》 2013年第4期173-179,共7页
A linear mixed model is used to determine the explaining infant mortality rate data of United Nations countries. The HDI (human development index) has a significant negative linear relationship with infant mortality... A linear mixed model is used to determine the explaining infant mortality rate data of United Nations countries. The HDI (human development index) has a significant negative linear relationship with infant mortality rate. United Nations data shows that the infant mortality rate has a descending trend over the period 1990-2010. This study aims to assess the value of the HDI as a predictor of infant mortality rate. Findings in the paper suggest that significant percentage reductions in infant mortality might be possible for countries for controlling the HDI. 展开更多
关键词 Infant mortality rate human development index linear mixed models
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Quality and Testing Standards on Rice Production in China and Development Strategies
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作者 XIE LiHong CHEN Neng DUAN BinWu 《China Standardization》 2006年第3期16-20,共5页
China is the biggest country of rice production and consumption in the world;more than 50% of the population feeds chiefly on rice. The quality of rice and its role as a staplefood carry much weight. The rice qualitie... China is the biggest country of rice production and consumption in the world;more than 50% of the population feeds chiefly on rice. The quality of rice and its role as a staplefood carry much weight. The rice qualities are those aspects concerning processing, appearance,cooking, nutrition and safety of the product. The study, formulation and implementation of standardson rice qualities and testing bear heavily on the improving of rice qualities, human health,substitution of rice varieties, promoting quality rice production and regulating rice market. 展开更多
关键词 rate Quality and Testing Standards on Rice Production in China and Development Strategies
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Development of Heart Rate Variaty in the Early and Rehabilitation Phase of AMI
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作者 冯建章 冯秀华 《South China Journal of Cardiology》 CAS 2000年第1期1-3,共3页
Heart rate variaty (HRV) of 85cases with AMI was observed in the early phase after onset and rehabilitation phase at first month and sixth month, and was contrasted with six time threshold indices of 111 cases with co... Heart rate variaty (HRV) of 85cases with AMI was observed in the early phase after onset and rehabilitation phase at first month and sixth month, and was contrasted with six time threshold indices of 111 cases with coronary heart disease and that of 35 normal control. We found the HRV of AMI was apperantly lower in the acute phase than that of coronary heart disease and normal controls. HRV recovered gradually with inclining to be stable after half a year, but it was still lower than that of controls. Low HRV in early phase of AMI suggested the poor prognosis. 展开更多
关键词 Acute myocardial infarction Heart rate variaty Development
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薄荷醇对果蝇产卵驱避作用及毒杀效果
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作者 李迅 刘彤霄 +4 位作者 李隆琦 李一璇 姜雅琦 陈利荣 刘威 《昆虫学报》 CAS CSCD 北大核心 2024年第7期964-975,共12页
【目的】研究薄荷醇对常见几种果蝇Drosophila产卵的驱避作用,并通过后代存活率和发育历期及成虫死亡率以评价薄荷醇毒杀作用。【方法】应用产卵双向选择装置,在0.05%,0.1%和0.2%薄荷醇作用下检测果蝇的产卵选择性;利用双染料食物偏好... 【目的】研究薄荷醇对常见几种果蝇Drosophila产卵的驱避作用,并通过后代存活率和发育历期及成虫死亡率以评价薄荷醇毒杀作用。【方法】应用产卵双向选择装置,在0.05%,0.1%和0.2%薄荷醇作用下检测果蝇的产卵选择性;利用双染料食物偏好实验检测薄荷醇对果蝇的摄食行为影响;利用产卵装置,检测薄荷醇对黑腹果蝇D.melanogaster的位置的影响;利用黑暗条件、摘除触角和前腿以及Orco 2突变体测定薄荷醇对黑腹果蝇产卵选择性的影响;并测定薄荷醇对黑腹果蝇后代存活率与发育历期的影响;测定薄荷醇对黑腹果蝇成虫寿命、奔跑速度和攀爬速度的影响;利用二氢乙锭(dihydroethidium,DHE)荧光染色技术,评估喂食1%薄荷醇3 d后黑腹果蝇成虫肠道内活性氧(reactive oxygen species,ROS)水平。【结果】薄荷醇对果蝇雌成虫产卵有驱避性,在0.05%,0.1%和0.2%薄荷醇作用下黑腹果蝇雌成虫的产卵指数分别为-0.42,-0.58和-0.98;铃木氏果蝇D.suzukii、雅库巴果蝇D.yakuba和拟暗果蝇D.pseudoobscura雌成虫对薄荷醇的产卵避性反应与黑腹果蝇雌成虫相同。在摄食过程中,黑腹果蝇及铃木氏果蝇成虫均对薄荷醇培养基产生明显排斥反应。薄荷醇培养基对黑腹果蝇成虫有明显的位置驱避性,0.05%,0.1%和0.2%薄荷醇处理下位置指数分别为-0.32,-0.44和-0.84。各个浓度的薄荷醇对黑暗环境和摘除前足的黑腹果蝇雌成虫仍然表现出显著的产卵驱避性,但在摘除黑腹果蝇成虫触角的条件下,薄荷醇对它们的产卵驱避性显著降低,0.05%,0.1%和0.2%薄荷醇作用下产卵指数分别为-0.04,-0.06和-0.26,薄荷醇对Orco 2突变体仍旧有产卵驱避性。与对照组相比,1%薄荷醇处理组黑腹果蝇成蛹和成虫羽化时间明显延长,分别延长了0.74和0.73 d,存活率明显下降,分别下降了63.2%和91.3%。随着薄荷醇浓度的增加黑腹果蝇成虫存活率呈现下降的趋势,且明显降低其奔跑和攀爬速度,即薄荷醇降低了亲代黑腹果蝇的适合度。1%薄荷醇处理3 d显著提升了黑腹果蝇成虫肠道内的ROS水平。【结论】薄荷醇通过嗅觉介导了果蝇的产卵避性反应,且薄荷醇降低了后代和亲代的适合度和存活率。 展开更多
关键词 果蝇 薄荷醇 产卵避性 嗅觉系统 发育历期 存活率
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Sustainability Assessment of Banana (Musa spp.) Yield Gap Reduction through Value Chain Development Interventions in Smallholder Farming Systems in Manicaland, Zimbabwe
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作者 Mthintwa Tawanda Hove Hlamalani Ngwenya Johan Van Niekerk 《Agricultural Sciences》 2024年第8期962-992,共31页
This study evaluated the effectiveness of donor supported agricultural value chain development projects in sustainably narrowing yield gaps for banana smallholder farmer producers in Manicaland, Zimbabwe. The study us... This study evaluated the effectiveness of donor supported agricultural value chain development projects in sustainably narrowing yield gaps for banana smallholder farmer producers in Manicaland, Zimbabwe. The study used a mixed methods research design that relied on farmers records for the quantitative analysis and focus group discussion and in-depth interviews for key experts for the qualitative aspects. A mix of regression analysis, t-tests, Pearsons’s correlation and analysis of variance statistical methods were used for the quantitative analysis while thematic response analysis was used for the qualitative engagements. The findings showed that by the end of the activity, the project had successfully narrowed the banana yield gaps to 18.66 tons per hectare working with a potential yield base of 40 tons. However, 5 years after the project closure the yield gap had fallen to 24.7 tons indicating a lack of sustainability of yield gap reduction. However, the yield gap slump does not override the fact that farmers on average were still able to sell approximately 5 tons per every 6 months after 5 years from the project closure which is beyond any poverty threshold. This suggests genuine upward economic mobility. Additionally, in analyzing what factors had the greatest influence on yield gap reduction, the access to fertilizer ranked highest where genetics, irrigation and improved agronomy followed in that respective order. The study further showed that farmers who receive value chain development support whilst at an already commercialized state tend to maintain productivity thresholds higher in comparison to those who are at a pre commercial state. This is evidenced by the fact that the pre commercial farmers had a yield reduction of 30.83 percent after 5 years of the project closure whereas the former realized a productivity growth of 7.84%. In conclusion, whilst the intervention was successful in transitioning farmers out of poverty, more investment should be made towards transitioning smallholder farmers to integrated soil fertility management practices and improvement of agronomic efficiency through stronger on field collaboration between research institutions, the government and development institutions. 展开更多
关键词 Yield Gap Value Chain Development Soil Health Varietal Replacement rate Sustainability and Economic Mobility
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Exploring the Association between Climate Change and Human Development: A Visual Analytics Study
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作者 Dongli Zhang Wullianallur Raghupathi Viju Raghupathi 《Atmospheric and Climate Sciences》 2024年第4期368-395,共28页
This study explores the complex relationship between climate change and human development. The aim is to understand how climate change affects human development across countries, regions, and the global population. Vi... This study explores the complex relationship between climate change and human development. The aim is to understand how climate change affects human development across countries, regions, and the global population. Visual analytics were used to examine the impact of various climate change indicators on different aspects of human development. The study highlights the urgent need for climate change action and encourages policymakers to make decisive moves. Climate change adversely affects numerous aspects of daily life, leading to significant consequences that must be addressed through policy changes and global governance recommendations. Key findings include that regions with higher CO2 emissions experience a significantly higher incidence of life-threatening diseases compared to regions with lower emissions. Additionally, higher CO2 emissions correlate with consistent death rates. Increased pollution exposure is associated with a higher prevalence of life-threatening diseases and higher rates of malnutrition. Moreover, greater mineral depletion is linked to more frequent life-threatening diseases, suggesting that industrialization contributes to adverse health effects. These results provide valuable insights for policy and decision-making aimed at mitigating the impact of climate change on human development. 展开更多
关键词 Air Pollution Climate Change CO2 Emissions Death rate GDP Human Development Visual Analytics
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