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The Spatial Distribution Characteristics of Resident Population Growth Rate in Henan Province, China
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作者 Kaiguang Zhang Hongling Meng +1 位作者 Mingting Ba Danhuan Wen 《Journal of Geoscience and Environment Protection》 2024年第11期191-206,共16页
Population is an important strategic resource for national development, a fundamental element of socio-economic development. The coordinated development of population and economy is an effective way to achieve rapid e... Population is an important strategic resource for national development, a fundamental element of socio-economic development. The coordinated development of population and economy is an effective way to achieve rapid economic growth. Based on the population statistics data of counties (districts) in Henan Province, China, from 2006 to 2021. The paper firstly uses the logistic population growth mathematical model to calculate the resident population growth rate of counties (districts), then utilizes the hotspot analysis and spatial semi-variogram analysis, to research the spatial distribution characteristics of the resident population growth rate in Henan Province. The research results show that the evolution of the regional resident population in the province basically conforms to the logistic natural growth model. The resident population growth rate shows the characteristics of high in the north and low in the south, high in the center and low in the surrounding regions. The resident population growth rate is positively correlated with the level of economic development;the urban built-up areas, especially the new regions in urban planning, have a fast growth rate of resident population, which has a significant siphon effect on the population of surrounding regions. The hotspots of resident population growth rate in the province are mainly distributed in the urban built-up areas and surrounding regions of Zhengzhou, Luoyang, and Xinxiang, accounting for about 3.51% of the total area of the province. The cold spots are mainly distributed in the eastern part of the province, forming zonal distribution, which spans across Shangqiu City, Zhoukou City, and Zhumadian City, accounting for about 8.61% of the total area of the province. The area with negative growth of resident population accounts for approximately 53.47% of the total province. The spatial distribution of the growth rate of the resident population in the whole province basically conforms to the spherical model, with a small dispersion degree and a short range. In the range, there is a high degree of variability in resident population growth rate. 展开更多
关键词 Resident population Growth rate Logistic Natural Growth Model Cold and Hot Spot Analysis Semi-Variogram Function Spatial Interpolation Henan Province
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The impact of COVID-19 on the birth rate in Nigeria:a report from population-based registries
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作者 Charlotte Blanche Oguejiofor Kenechi Miracle Ebubechukwu +32 位作者 George Uchenna Eleje Emmanuel Onyebuchi Ugwu Joseph Tochukwu Enebe Kingsley Emeka Ekwuazi Chukwuemeka Chukwubuikem Okoro Boniface Chukwuneme Okpala Charles Chukwunomunso Okafor Nnanyelugo Chima Ezeora Emeka Ifeanyi Iloghalu Chidebe Christian Anikwe Chigozie Geoffrey Okafor Polycarp Uchenna Agu Emeka Philip Igbodike Iffiyeosuo Dennis Ake Arinze Anthony Onwuegbuna Osita Samuel Umeononihu Onyedika Promise Anaedu Odigonma Zinobia Ikpeze David Chibuike Ikwuka Henry Ifeanyi Nwaolisa Ekene Agatha Emeka Jude Ogechukwu Okoye Ihechinyerem Kelechi Osuagwu Angela Ogechukwu Ugwu Toochukwu Benjamin Ejikeme Eziamaka Pauline Ezenkwele Chijioke Ogomegbunam Ezeigwe Malarchy Ekwunife Nwankwo Gerald Okanandu Udigwe Joseph Ifeanyichukwu Ikechebelu Grace Agbaeze Chukwuebuka Divine Nwanja Ahizechukwu Chigoziem Eke 《Infectious Diseases Research》 2023年第1期14-18,共5页
Background and objectives:Coronavirus disease 2019(COVID-19)is a pandemic that has become a major source of morbidity and mortality worldwide,affecting the physical and mental health of individuals influencing reprodu... Background and objectives:Coronavirus disease 2019(COVID-19)is a pandemic that has become a major source of morbidity and mortality worldwide,affecting the physical and mental health of individuals influencing reproduction.Despite the threat,it poses to maternal health in sub-Saharan Africa and Nigeria,there is little or no data on the impact it has on fertility,conception,gestation and birth.To compare the birth rate between pre-COVID and COVID times using selected months of the year.Materials and methods:This was a secondary analysis of cross-sectional analytical study data from the birth registries of three tertiary hospitals,comparing two years[2019(Pre-COVID)]versus[2020(COVID era)]using three months of the year(October to December).The data relied upon was obtained from birth registries in three busy maternity clinics all within tertiary hospitals in South-East Nigeria and we aimed at discussing the potential impacts of COVID-19 on fertility in Nigeria.The secondary outcome measures were;mode of delivery,booking status of the participants,maternal age and occupation.Results:There was a significant decrease in tertiary-hospital based birth rate by 92 births(P=0.0009;95%CI:-16.0519 to-4.1481)among mothers in all the three hospitals in 2020 during the COVID period(post lockdown months)of October to December.There was a significant difference in the mode of delivery for mothers(P=0.0096)with a 95%confidence interval of 1.0664 to 1.5916,as more gave birth through vaginal delivery during the 2020 COVID-19 period than pre-COVID-19.Conclusion:Tertiary-hospital based birth rates were reduced during the pandemic.Our multi-centre study extrapolated on possible factors that may have played a role in this decline in their birth rate,which includes but is not limited to;decreased access to hospital care due to the total lockdowns/curfews and worsening inflation and economic recession in the country. 展开更多
关键词 birth rates COVID-19 lockdown NIGERIA PANDEMIC pre-COVID
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Effect of Dual Trigger In Vitro Fertilization and Intracytoplasmic Sperm Injection During the Gonadotropin-releasing Hormone-Antagonist Cycle on Final Oocyte Maturation and Cumulative Live Birth Rate in Women with Diminished Ovarian Reserve 被引量:1
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作者 Yu-meng REN Yan-bin WANG +4 位作者 Min FU Qiu-xiang ZHANG Huan SHEN Hong-jing HAN Fu-mei GAO 《Current Medical Science》 SCIE CAS 2022年第5期1066-1070,共5页
Objective It is well known that a dual trigger treatment can improve clinical outcomes of in vitro fertilization(IVF)in high or normal ovarian responders.However,it is not clear whether dual triggering also benefits p... Objective It is well known that a dual trigger treatment can improve clinical outcomes of in vitro fertilization(IVF)in high or normal ovarian responders.However,it is not clear whether dual triggering also benefits patients with diminished ovarian reserve(DOR).The aim of this study was to investigate whether a dual trigger treatment of gonadotropin-releasing hormone(GnRH)agonist combined with human chorionic gonadotropin(hCG)for final follicular maturation improves the cumulative live birth rate(CLBR)during the GnRH-antagonist cycle in patients with DOR.Methods This retrospective study included patients with DOR who received a GnRH-antagonist protocol during IVF and intracytoplasmic sperm injection(IVF-ICSI)cycles at Peking University People’s Hospital from January 1,2017 through December 31,2017.Oocyte maturation was triggered by GnRH combined with hCG(n=110)or hCG alone(n=71).Embryos were transferred on the third day after oocyte retrieval or during a subsequent freeze-thaw cycle.Patients were followed up for 3 years.Results The dual trigger treatment did not affect CLBR,which is an overall determinant of the success rate of assisted reproductive technology(ART).Women in the dual trigger group had significantly higher rates of fertilization than those in the hCG group(90.1%vs.83.9%,P=0.040).Conclusion Dual trigger with GnRH agonist and hCG did not improve CLBR in patients with DOR,but did slightly improve fertilization rate,oocyte count,and embryo quality. 展开更多
关键词 dual trigger gonadotropin releasing hormone antagonist protocols diminished ovarian reserve cumulative live birth rate
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Determinants of Home Deliveries by Pregnant Mothers in Lumbo Chabbobboma Zone of Gwembe District in Zambia
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作者 Miyoba M. Habanji 《Open Journal of Obstetrics and Gynecology》 2024年第6期938-966,共29页
Background: Home deliveries is still high globally at 42% WHO 2022, due to high home deliveries, maternal death is also high at 43% globally. In sub-Sahara region home deliveries still high. Giving birth at health fac... Background: Home deliveries is still high globally at 42% WHO 2022, due to high home deliveries, maternal death is also high at 43% globally. In sub-Sahara region home deliveries still high. Giving birth at health facilities in most of sub-Saharan African countries Zambia inclusive is still a challenge whereby more than 51% of first-time mothers give birth at home and this gives a risk of high maternal and perinatal deaths. Therefore Reducing number of home deliveries is important to improve maternal and perinatal health issues. In this study, the aim was to investigate the determinants of home deliveries by pregnant mothers in the Luumbo zone of Gwembe district, Zambia. Purpose: Access to skilled care and facilities with capacity to provide emergency and newborn care is critical to reduce maternal death. In Zambia 42% of women still deliveries from home, suggesting a persistent challenge for women to seek, reach, and receive quality maternity care. This study aimed investigate the determinants of home deliveries by pregnant mothers in Luumbo zone of Gwembe district, Zambia. Methods: The study was conducted among postnatal mothers who came for postnatal care at 6 weeks in Luumbo Chabbobboma clinic in Gwembe district southern province of Zambia. This was a descriptive cross-sectional study where a Simple random sampling technique was used to select 105 women of childbearing age who attended postnatal and had a recent delivery. Data were collected using a researcher-administered structured questionnaire to identify determinants of home deliveries in Luumbo Chabbobboma zone. Data analysis was done using SPSS computer software version 27.0. Both descriptive and inferential (chi-square test) analyses were performed and statistical significance was taken at α ≤ 0.05. Results: The results show that 46 (43.8%) respondents were in the age bracket 20 - 29 years. Of the 105 respondents included in the study, 24 (22.9%) of them delivered from home. The results show that high maternal age (p = 0.03), occupation (p = 0.024), distance to the facility (p = 0.014), means of transportation (p = 0.023), multiparity (p = 0.01), timing and number of ANC visits (p Conclusion: From this population. The major reason why women still deliver at home was long distance to the nearest facility. To reduce maternal and perinatal mortality access to health facilities by pregnant women needs to be improved. There should also be active engagement of the traditional and religious institutions in the area. 展开更多
关键词 Antenatal Care Factors Home birth Cultural Factors Maternal Mortality rate Skilled Delivery Home Delivery PREVALENCE Zambia
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The Control Efficiency of Plant Alcohol Extracts on the Laboratory Populations of Myzus persicae(Sulzer)and Lipaphis erysimi (Kaltenbach) 被引量:8
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作者 ZHOU Qiong, LIANG Guang-wen ,ZENG Ling and SHEN Shu-ping(Department of Biology, Xiangtan Normal University, Xiangtan 411201 , P. R. China Laboratory of Insect Ecology , South China Arigcultural University ,Guangzhou 510642 , P. R. China) 《Agricultural Sciences in China》 CAS CSCD 2002年第11期1199-1203,共5页
The effects of semiochemicals extracted from 63 species of plants, on peach aphid (Myzus per-sicae) and mustard aphid (Lipaphis erysimi), were studied in laboratory. The deterrent rate, reproduction deterrent index an... The effects of semiochemicals extracted from 63 species of plants, on peach aphid (Myzus per-sicae) and mustard aphid (Lipaphis erysimi), were studied in laboratory. The deterrent rate, reproduction deterrent index and the interferential index of population control (IIPC) was used to evaluate the efficiency of semiochemicals on population control of the two target aphids. The results showed that the extracts of 34 species of common plants have noticeable effect on both aphid populations, especially, Xanthium sibiricum Petr. Et Widd. and Syngonium podophyllum Schott. These plant extracts could be used to construct the plant pro-tectant to protect crops. 展开更多
关键词 Plant alcohol extracts Peach aphid [Myzus persicae(Sulzer)] Mustard aphid [Lipaphis erysimi (Kaltenbach)] Deterrent rate Interferential index of population control (IIPC)
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Intra-specific variations of two Leymus chinensis divergence populations in Songnen Plain, Northeast China
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作者 WANG Ren zhong (Laboratory of Quantitative Vegetation Ecology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.) 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2002年第1期20-26,共7页
Population demography, seed production, biomass allocation, net photosynthesis and transpiration of two Leymus chinensis divergent populations and between two years in Songnen plain, northeast China were compared.... Population demography, seed production, biomass allocation, net photosynthesis and transpiration of two Leymus chinensis divergent populations and between two years in Songnen plain, northeast China were compared. Strong differences between the dry 1997 and moist 1998 occurred in vegetative shoot and sexual shoot densities, sexual differentiation and tiller densities, as well as in the lengths of inflorescence, seed numbers per inflorescence, seed weights and biomass allocation in each population respectively ( P < 0.01). While strong differences between the two populations occurred in vegetative shoot densities, sexual shoot densities, sexual differentiation and seed weights in each year ( P < 0.01). The differences between the two populations in tiller densities and in biomass allocation to sexual shoots were significant ( P <0.05). But there were no significant differences between the two populations in the lengths of inflorescence, seed numbers per inflorescence and biomass allocation to rhizomes and vegetative shoots ( P >0.05). Excepting the transpiration rate in the early June, the differences between the two populations in net photosynthesis and transpiration rate of vegetative shoots and sexual shoots were strongly significant in the early June and July respectively ( P <0.01). Relative stable variations in population demography and physiological traits between the two populations indicated that they are divergently in the Songnen Plain. 展开更多
关键词 population demography seed productions biomass allocation net photosynthetic rate transpiration rate Leymus chinensis populations Songnen Plain
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Effects of anthropogenic disturbances on natural regeneration and population structure of gum arabic tree (Acacia senegal)in the woodlands of Lake Baringo ecosystem, Kenya
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作者 Stephen F. Omondi David W. Odee +2 位作者 George O. Ongamo James I. Kanya Damase P. Khasa 《Journal of Forestry Research》 SCIE CAS CSCD 2017年第4期775-785,共11页
Despite the ecological and economic importance of Acacia senegal, little is known about the effects of anthropogenic disturbances on its natural regeneration patterns and population structure. We investigated the effe... Despite the ecological and economic importance of Acacia senegal, little is known about the effects of anthropogenic disturbances on its natural regeneration patterns and population structure. We investigated the effects of these factors within the Lake Baringo woodland ecosystem. Data was collected from 60 plots of 20 m × 20 m systematically distributed in four A. senegal-dominated populations within the Lake Baringo woodland. Sample populations spanned a degradation gradient measured by a population disturbance index (PDI). Trees were measured for diameter at breast height (DBH) and categorized by growth stages: seedling, sapling and adult tree. Higher seedling and sapling densities were recorded in lightly than heavily disturbed populations, but only sapling density was significantly different between the two disturbance levels (P = 0.02). Lightly disturbed populations revealed a reversed J-shape size-class distribution (SCD) indicative of stable structure unlike the heavily disturbed populations. The quotient and permutation indices indicated unstable populations with episodic recruitment and mortality. Our study reveals that natural regeneration and population structure of A. senegal were affected majorly by selective harvesting and heavy browsing. Suitable management strategies to control livestock grazing and illegal tree harvesting within the woodland is required to promote conservation of the species genetic resources 展开更多
关键词 Anthropogenic disturbance population dynamics Renewal rate Selective harvesting Tropical woodland
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Is It Wrong to Apply the Intrinsic Rate of Natural Increase to Individuals and Compare It among Genotypes?
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作者 Takahiro Miyo 《Open Journal of Genetics》 2018年第1期1-13,共13页
In order to gain insights into the seasonal dynamics of genetic variation in insecticide resistance within a natural population of Drosophila melanogaster during population growth, which we considered the most importa... In order to gain insights into the seasonal dynamics of genetic variation in insecticide resistance within a natural population of Drosophila melanogaster during population growth, which we considered the most important ecological factor there, we conducted a series of genetic analyses of resistance factors involved in that population and compared individual-based intrinsic rates of natural increase among resistance genotypes. However, some researchers have argued that it is a misconception to apply the intrinsic rate of natural increase to individuals, because it is a population parameter. We consider that their criticisms were incorrect. In this article, I described our research briefly and set forth the reasons why we conducted these studies. 展开更多
关键词 Drosophila MELANOGASTER INSECTICIDE Resistance Intrinsic rate of NATURAL Increase NATURAL population
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An assessment of factors leading to the decline of Beclardia macrostachya (orchidaceae) population in Mauritius
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作者 Vishwakalyan Bhoyroo Daneshwar Puchooa +1 位作者 Vijayanti Mala Sanmukhiya Sanmukhiya Elisabeth Rababakonandrianina 《Advances in Bioscience and Biotechnology》 2013年第3期317-330,共14页
Clearing of forest land for agriculture and urbanization following colonization have reduced the forest cover in Mauritius to 3% of total land cover. Today exotic species such as Psidium cattleianum (wild guava), Arau... Clearing of forest land for agriculture and urbanization following colonization have reduced the forest cover in Mauritius to 3% of total land cover. Today exotic species such as Psidium cattleianum (wild guava), Araucaria columnaris, and Ravenala madagascarensis dominate at Pigeon Wood, the only site in Mauritius where Beclardia can be found, leaving little space for very few indigenous tree species like Labourdonnaisia glauca, Apholoia theiformis and Foetida mauritiana. Beclardia macrostachya is an orchid endemic to Mauritius, Madagascar andReunion. Though it is abundant in the latter countries, it is one of the rarest orchids in Mauritius. An assessment of the factors associated with the stability of this orchid was carried out in forests of these three countries to understand the drastic decline of this orchid in Mauritius. Morphometric and fertility counts carried out at different forests revealed differences in fitness and fertility rates among forests of the same countries and between different countries. Stability of the different Beclardia populations was carried out based on counts of juveniles and adults. Higher fertility rates and most stable populations were observed in the forests of Reunion Island (Bebours) and Madagascar (Ambohitanteley), whereas very low fruit set were observed in Mauritius, unless manual pollination was carried out. Microscopic analysis revealed the presence of pelotons of endomycorrhiza during the early development of the seedlings, in vivo. Based on comparative studies among the different sites, pollinator limitation and absence of suitable hosts were the primary factors that led to the present decline in Mauritius. The high density of wild guava, Psidium cattleianum, which has slowly taken up most of the forest areas inMauritiushas affected the regenerating capacity of Beclardia macrostachya and the density of putative hosts of this orchid. GC-MS/MS analysis of nectar revealed α-D- glucopyranose to be the primary reward of the pollinators and benzyl alcohol, methoxybenzyl alcohol and methoxy methyl phenol to be components floral fragrance. 展开更多
关键词 Beclardia macrostachya Conservation Fertility rate population Dynamics POLLINATOR Limitation PSIDIUM Cattleianum
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The Role of Nuclear Regulators in Reviewing Population Growth Projections
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作者 Samia Morsy Medhat Abdel-Aal 《Journal of Environmental Science and Engineering(A)》 2013年第7期447-452,共6页
One of the roles of nuctear regulators is to review population projections calculated by applicants for populations lying in the vicinity of nuclear power plants. This paper examines methods of calculating rates of gr... One of the roles of nuctear regulators is to review population projections calculated by applicants for populations lying in the vicinity of nuclear power plants. This paper examines methods of calculating rates of growth and thus calculating future population growth. This paper is concerned about regulators making sure that nuclear power plants are not located near densely populated centers and that population centers located near nuclear power plants do not become densely populated. In the case of El Dabaa city in the north coast of Egypt, south west of the nominated plant site, three rates of growth 1.5%, 2.5% and 3% were identified. The first is the current population growth rate of the city, the second is the average national growth rate and the third is the expected growth rate of the city when the nuclear power plant gets constructed and operated. In all three cases, this city is a population center and rules of distance from the nuclear power plant shall apply. Thus the further natural growth of this city should be controlled and directed away from the downwind of the plant. 展开更多
关键词 Nuclear regulators APPLICANT nuclear power plant population growth projections rates of growth population centers downwind direction.
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Analysis of the Main Characteristics of the Population in the Mariovo Region as Part of the Crna Reka Basin in the Republic of Macedonia
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作者 Cane Koteski Nikola V.Dimitrov Zlatko Jakovlev 《Journal of Tourism and Hospitality Management》 2018年第2期73-88,共16页
In the scientific paper,the demographic discharge is treated as the main problem where the Mariovo region is located in the South-eastern part of the Republic of Macedonia,a region that covers an area of 828 km2,in wh... In the scientific paper,the demographic discharge is treated as the main problem where the Mariovo region is located in the South-eastern part of the Republic of Macedonia,a region that covers an area of 828 km2,in which the Municipality of Vitoliste covers a total area of 495 km2 and the Municipality of Staravina with a total area of 333 km2,a region in which there are 25 village settlements,the Municipality of Vitolishte has 14 villages and the Staravina Municipality has 11 villages,a region that lost more than 95%of its population in the period from 1961 to 2002,through various migrations to the closer cities in the state and part left as economic migrants in other countries.The purpose of this scientific paper is to provide answers to questions as how to stop the devastation of this region and how to revitalize this region and make people return to live in this space again.Methods of study used include:geographical methods,statistical-mathematical methods,cartographic methods,information methods,cabinet-laboratory methods,and field researches that were made in the period from May to June 2003.The paper deals with the following:the numerical and natural movement of the population,migrations,population by age and gender,territorial distribution of the population,national structure,and educational characteristics of the population.At the end of the research,the findings include the reasons,consequences and measures for its revitalization in the next 10 years of the Mariovo region as part of the Crna Reka basin in the Republic of Macedonia. 展开更多
关键词 numerical MOVEMENT birth rate MORTALITY migration age SEX PREVALENCE
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The Determinants of Population Growth in Rwanda
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作者 Daniel Ruturwa Sebikabu Ignace H.Kabano 《Journal of Economic Science Research》 2019年第3期37-44,共8页
The fertility occupies a central position in the study of population growth.The growth of the population depends entirely on human fertility,including birth,death rates and life expectancy.Growth of the fertility is o... The fertility occupies a central position in the study of population growth.The growth of the population depends entirely on human fertility,including birth,death rates and life expectancy.Growth of the fertility is one of the key determinants of the Population Growth.This paper focused on the determinant factors of population growth in Rwanda.From the findings,there is a statistically significance of fertility trends at 0.05 percent because the t-statistic in table-4 is greater than its critical value(1.96)at 0.05 percent.The results provides evidence of Fertility,birth,death and life expectancy as factors which boost population to grow in Rwanda.The results founded,indicate the existence of high fertility rates even decreasing,lead to increase population due to its positive values over time.This means that Fertility rates in Rwanda has a positive impact on the country's population growth,especially in the youth who realizes around 48 percent of entire Rwandan’s Population.The relationship between fertility rate and the time describe a decreasing function,which interesting for us showing that fertility has been reduced over time.In other words,as well as the years increased,the fertility decreased.The coefficient of Time is(-0.117035)which implies that a unit change in time will change Total Fertility Rate(TFR)by(-0.117035),table-1.The model of fertility represents a decreasing function while the time function still increasing,as shows in the figure-2.The fertility variable has positive relationships with the population dependent variable even the fertility coefficient is negative,the probability p-value is significant at 0.05 significance level on one hand and the absolute t-statistic is great than the critical value at 0.05 level of significance,which confirm the statistically significance of t-statistic.The coefficients on the death rate and Life expectancy are respectively positive and significant at all confidence level,table-5. 展开更多
关键词 population FERTILITY birth DEATH LIFE EXPECTANCY Rwanda
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Effects of N Rates on Canopy Microclimate and Population Health in Irrigated Rice 被引量:17
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作者 贺帆 《Agricultural Science & Technology》 CAS 2009年第6期79-83,共5页
Objective The aim was to elucidate the effects of N rates on rice canopy microclimate and community health so as to provide a sci- entific basis for studying the production potential in irrigated rice with healthy can... Objective The aim was to elucidate the effects of N rates on rice canopy microclimate and community health so as to provide a sci- entific basis for studying the production potential in irrigated rice with healthy canopy. Method The effects of rice population structure traits under different N rates on rice canopy temperature, relative humidity ( RH), light transmittance and sheath blight were studied by using Sunscan canopy analysis system and HOBO( Pro Temp/RH IS logger). Result The results showed that leaf area index, plant height and tiller number had significant effects on canopy cooling, RH enhancing and light reducing. Extremely significant multiple linear regression relationships existed among canopy day temperature, day RH, LAI and tiller number, and among light transmittance, tiller number and plant height. At flowering stage, per unit LAI could result in a day-maximum-temperature (Tmax) deceasing of 0.87℃ and a day-minimum-RH (RHmin) enhancing of 2.5% within canopy. Similarly, 100 plants per ms could respectively cause a Tmax deceasing of 1.23℃ and an RHmin enhancing of 3.3% in rice canopy. And per 10 cm plant height and 100 plants per m^2 could respectively reduce 9.3% and 7.8% of light in canopy. Conclusion Sheath blight disease index was significantly enhanced as the canopy day temperature decreased, day RH increased and light transmittance reduced. Bigger canopy from higher nitrogen level treatment leads to a more stable canopy microclimate with little changes in temperature and RH during day and night, which has the risk of worsening canopy health. Thus, moderately controlling the space development of canopy is the basis of constructing healthy canopy in rice. 展开更多
关键词 RICE N rates Canopy microclimate population structure Sheath blight
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Role of ICSI in Non-male Factor Cycles as the Number of Oocytes Retrieved Decreases from Four to One 被引量:3
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作者 Na GUO Xiang HUA +1 位作者 Yu-feng LI Lei JIN 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2018年第1期131-136,共6页
This study aimed to investigate whether intracytoplasmic sperm injection(ICSI) shows an advantage over in vitro fertilization(IVF) in non-male factor cycles as the number of oocytes retrieved decreases from four t... This study aimed to investigate whether intracytoplasmic sperm injection(ICSI) shows an advantage over in vitro fertilization(IVF) in non-male factor cycles as the number of oocytes retrieved decreases from four to one.We undertook a retrospective analysis of 1305 IVF/ICSI cycles of non-male factor in which four or fewer oocytes were retrieved.Comparisons were made between conventional IVF(CI) and ICSI when one,two,three or four oocyte(s) were retrieved.Primary outcomes including normal fertilization rate,proportion of embryos per obtained oocyte,cycle cancellation rate,implantation rate,clinical pregnancy rate(PR),live birth rate(LBR),cumulative PR and cumulative LBR were evaluated.The results showed that the normal fertilization rate(72.5% vs.50.0%) and the proportion of embryos per obtained oocyte(72.5% vs.55.0%) were significantly increased in one oocyte retrieved cycles in ICSI group as compared with CI group.However,the proportion of embryos per obtained oocyte was markedly decreased in ICSI group when three(52.3% vs.61.3%) or four(56.9% vs.64.0%) oocytes were retrieved.The implantation rates,clinical PRs,LBRs,cumulative PRs and cumulative LBRs in CI group were comparable to those in ICSI group when one,two,three or four oocyte(s) were retrieved.In conclusion,ICSI doesn't show advantages over IVF in low oocyte yield cycles of non-male factors,even when only one oocyte was retrieved.Key words 展开更多
关键词 low oocyte yield intracytoplasmic sperm injection in vitro fertilization oocytenumber cumulative live birth rate
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Population Characteristics and Future Population Countermeasures for the Studied Counties in Tibet, China 被引量:1
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作者 LIUJian PENGChuan-zhong +1 位作者 Xiang-mei ZHONGXiang-hao 《Wuhan University Journal of Natural Sciences》 EI CAS 2005年第4期739-744,共6页
Focusing on the 18 counties along “One River and Two Tributaries” region, and based on the data from China 3nl, 4th and 5th population censuses, this article has analyzed the time and spatial changing patterns of th... Focusing on the 18 counties along “One River and Two Tributaries” region, and based on the data from China 3nl, 4th and 5th population censuses, this article has analyzed the time and spatial changing patterns of the population in this region. The analyses show that since the 3nl population census, total population, average age and total birth rate have all changed considerably: ① Total population has grown, fast, with most counties' annual average growth rate of more than 10. ② In terms of the region's average age, in 2000 the age in the 18 counties is younger than 30 years old. ③ Compared with the 3nl population census, labor force by the 5th census is much younger. ④ Countermeasures are proposed to control population by controlling birth rate as the result of the local resident's quality improvement by education. 展开更多
关键词 Key words average age total birth rate dependency index population development countermeasures One River and Two Tributaries region TIBET
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Effect of bis(tributyltin)oxide on reproduction and population growth rate of calanoid copepod Schmackeria poplesia 被引量:1
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作者 黄瑛 朱丽岩 +1 位作者 邱旭春 张天文 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2010年第2期280-287,共8页
A full life-cycle toxicity test, combined with histology, on calanoid copepod Schmackeria poplesia was used to study the effect of bis(tributyltin) oxide (TBTO). The results indicate no sex-specific differences in... A full life-cycle toxicity test, combined with histology, on calanoid copepod Schmackeria poplesia was used to study the effect of bis(tributyltin) oxide (TBTO). The results indicate no sex-specific differences in TBTO toxicity. Long-term mortalities of the copepods exposed to concentrations higher than 20 ng TBTO L"1 were significantly elevated compared with that of control, and larval development was inhibited when they were exposed to 40 and 60 ng TBTO L-1. The percentages of ovigerous females were reduced compared with the control (P〈0.01) after 24 days exposure to concentrations higher than 10 ng TBTO L-1. Histological examinations suggest that exposure to TBTO might block the posterior end of the diverticula and inhibits the production of egg sacs. A modified Euler-Lotka equation was used to calculate a population-level endpoint, the intrinsic rate of natural increase (rm), from individual life-table endpoints, i.e. mortality rate, time of release of first brood, sex ratio, the fraction of ovigerous females among all females as well as the number of nauplii per ovigerous female. Apart from the highest TBTO concentration (60 ng LI), where all females aborted their egg sacs, 20 ng TBTO L-1 was the only concentration that significantly decreased rm compared with that of control (an effect associated with decreased sex ratio). The results show that the S. poplesia is affected by prolonged exposure to low concentrations of TBTO. The full life-cycle toxicity test combined with histology experiments provides more integral understanding of the toxicity of endocrine disrupters. 展开更多
关键词 TRIBUTYLTIN REPRODUCTION population growth rate GONAD Schmackeria poplesia toxicity testing
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Decreasing Birth Rate Determining Worldwide Incidence and Regional Variation of Female Breast Cancer 被引量:1
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作者 Wenpeng You Ian Symonds +1 位作者 Frank J. Rühli Maciej Henneberg 《Advances in Breast Cancer Research》 2018年第1期1-14,共14页
Purpose: Urbanization, obesity and ageing associated with lifestyle changes (Westernized diet patterns, pollution, physical inactivity) have been proposed as the major contributing factors for the global rise in breas... Purpose: Urbanization, obesity and ageing associated with lifestyle changes (Westernized diet patterns, pollution, physical inactivity) have been proposed as the major contributing factors for the global rise in breast cancer (BCa) and have been the variables used to predict the future breast cancer rate. At the same time, socio-economic level, instead of birth rate, has been proposed for explanation of dramatic regional variations of breast cancer incidence. We sought to determine which factor plays the determining role in predicting worldwide breast cancer incidence rates and regional variations. Methods: Bivariate correlation was conducted to examine the relationships between country-specific estimates of birth rate, BCa incidence, urbanization, overweight, ageing and GDP. Partial correlation was performed to identify the correlation between BCa incidence with each independent variable while we controlled the other four variables. Multiple linear regression was used to identify the most significant predictors of BCa incidence. Post hoc Scheff and independent T-Test analysis were performed to compare mean differences in BCa incidence rates and residuals of BCa standardised on birth rate in the WHO regions, and UN developed and developing regions respectively. Results: Worldwide, BCa incidence rate tends to increase while birth rate decreases and urbanization, overweight, ageing and GDP increase. However, birth rate was the only variable that had a significant correlation with BCa incidence when controlled for the other four variables. Birth rate was the only significant predictor of BCa incidence in regression analysis. Multiple mean differences of BCa incidence between regions were significant, but all disappeared when the contributing effect of birth rate on BCa incidence rate was removed. Conclusions: Birth rate plays a determining role in worldwide BCa incidence rate and regional variations. Current BCa projection methods may estimate future rates of BCa poorly if they fail to incorporate the impact of birth rate. 展开更多
关键词 Regional Variations HORMONES BREAST Cancer birth rate Mean Difference Comparison
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A growing captive population erodes the wild Red-crowned Cranes(Grus japonensis) in China 被引量:1
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作者 Daqing Zhou Xin Xia +5 位作者 Wanggu Xu Haonan Zhang Zhedong Qian Jun Gao Zhi Wang Mingkang Jiang 《Chinese Birds》 CSCD 2016年第4期210-217,共8页
Background: The Red-crowned Crane(Grus japonensis) is an endangered bird species and while the wild population continues to decrease in China, the captive population has dramatically increased over the last two decade... Background: The Red-crowned Crane(Grus japonensis) is an endangered bird species and while the wild population continues to decrease in China, the captive population has dramatically increased over the last two decades. We hypothesized that some of the captive Red-crowned Cranes originated from the wild and that a growing captive population is eroding the wild population in China.Methods: We surveyed the size of the population and determined the average annual growth rate, reproductive success rate and mortality rate of captive Red-crowned Cranes in 2013 in China. We assessed this erosion effect through mathematical models, in which the size of the captive Red-crowned Crane population was determined from the annual growth rate, the reproductive success rate and the rate of mortality.Results: We found there were a total of 1520 captive Red-crowned Cranes in 2013 in China, with an average annual gro-wth rate of 7.46%, a reproductive success rate of 9.17% and a mortality rate of 3.6%. We found that approximately 1027 supplementary Red-crowned Cranes per year and a total of 244, over the 14 year period from 1999 to 2013, were needed to account for the growing captive population in China.Conclusion: We conclude that the 244 birds probably came from the wild by taking eggs and capturing juveniles or adults and hence accepted the hypothesis. Perhaps more surprisingly, our annual estimate of the number of supplementary Red-crowned Cranes in captive populations is very conservative, with the erosion effect substantially underestimated, because the total number of captive Red-crowned Cranes in 2013 was underestimated, with the annual reproductive success rate in zoos overestimated. The existence of an erosion effect provides a new perspective for the interpretation of why the Red-crowned Crane population in the wild continues to decrease. In our opinion, it is important to understand the consequences of this erosion effect on the management and conservation of this endangered bird species in China. 展开更多
关键词 ZOO Nature reserve CRANE Captive population Reproductive success rate
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Cumulative live birth rates of in vitro fertilization/intracytoplasmic sperm injection after multiple complete cycles in China 被引量:1
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作者 Lei Huang Qun Lu +16 位作者 Jiangbo Du Hong Lv Shiyao Tao Shiyao Chen Xiuzhu Li Xiumei Han Kun Zhou Bo Xu Xiaoyu Liu Hongxia Ma Yankai Xia Guangfu Jin Hongbing Shen Xiufeng Ling Zhibin Hu Jichun Tan Feiyang Diao 《The Journal of Biomedical Research》 CAS CSCD 2020年第5期361-368,I0002-I0006,共13页
There were few studies of cumulative live birth rates(CLBRs) based on multicenter reproductive clinical data from the general Chinese population.Here we report a retrospective cohort study,including 14 311 women with1... There were few studies of cumulative live birth rates(CLBRs) based on multicenter reproductive clinical data from the general Chinese population.Here we report a retrospective cohort study,including 14 311 women with17 315 cycles,in three reproductive centers to evaluate two estimated parameters of CLBRs with multiple transfer cycles of in vitro fertilization(IVF)/intracytoplasmic sperm injection(ICSI) in a Chinese population.We found that CLBRs were related to female age and endometrial thickness.By the fourth transfer cycle,the conservative and optimal estimates of CLBRs were 52.95% and 77.30% in women under 30 years of age,and 18.17% and26.51% in those 37 years of age or older,respectively.The two estimates were 44.70% and 63.15% in women with endometrial thickness more than 7 mm,and 32.05% and 46.18% in those with less than 7 mm,respectively.In addition,body mass index(BMI),duration of infertility,and infertility diagnoses may also be related to CLBRs on certain conditions.The findings from this study on CLBRs after multiple transfer cycles of IVF/ICSI treatment on different conditions in the Chinese population should be beneficial to both infertile couples and clinicians. 展开更多
关键词 cumulative live birth rate in vitro fertilization intracytoplasmic sperm injection
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The Demographic Problem in Greece:Consequences and Solutions
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作者 Adrianos Pavlopoulos Theodoros Rachiotis 《Journal of Environmental Science and Engineering(A)》 CAS 2024年第3期100-110,共11页
Globally,population dynamics are shifting towards increased life expectancy,and many countries,including Greece,face significant demographic challenges.Greece is particularly impacted by one of the lowest birth rates ... Globally,population dynamics are shifting towards increased life expectancy,and many countries,including Greece,face significant demographic challenges.Greece is particularly impacted by one of the lowest birth rates in the world and a rapidly aging population.This demographic shift places unprecedented pressure on the nation’s pension systems and economic stability,as more people retire than enter the workforce.This study aims to explore the historical factors contributing to Greece’s demographic situation,analyze the consequences of current trends,and propose strategic solutions.The research utilizes a literature review approach and the case study of Greece to understand the depth and breadth of the demographic crisis.Key areas of focus include the declining birth rate,the economic implications of an aging population,and the potential of migration and policy reform to rejuvenate demographic dynamics.The study evaluates various policy interventions from other countries to propose a tailored,multi-faceted strategy for Greece.These strategies emphasize economic incentives for young families,improved childcare and parental support,healthcare investment,and inclusive migration policies to enhance workforce numbers.This comprehensive approach seeks to provide actionable insights that can help Greece mitigate the effects of demographic decline and foster a more sustainable future,aligning policy interventions with socio-economic and cultural realities. 展开更多
关键词 Demographic problem low birth rate IMPLICATIONS POLICIES REFORMS
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