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1.
研究生态环境与高质量发展耦合关系时空演变及驱动机制,对实现可持续发展、构建生态文明体系和建设美丽中国具有重要意义。综合构建了生态环境-高质量发展指标体系,运用耦合协调度模型、空间马尔科夫链和BP神经网络-地理加权回归组合模型,系统探讨2005-2020年福建省生态环境与高质量发展耦合关系的时空演变及驱动机制。结果表明:(1)研究期间,福建省生态环境指数整体稳定,而高质量发展指数呈现先降低后上升的变化趋势,二者在空间上的组合关系整体呈现错位特征。(2)福建省县域生态环境与高质量发展指标之间的耦合关系呈先降低后上升的趋势,且呈现明显的空间异质性。(3)协调发展和绿色发展是驱动生态环境质量提高的关键因素,其影响程度呈"圈层式"空间分布特征。 相似文献
2.
地区间发展不平衡是制约区域协调发展战略落实的重要障碍之一。基于2010—2019年长三角区域41个地级市的面板数据,构建了包含经济发展、科教事业、基础建设、人民生活、资源环境5个子系统的区域协调发展指标体系,借助GeoDa和ArcGIS软件,运用区域协调发展测度模型、探索性空间数据分析等方法,探讨区域协调发展的时空演变特征及各要素内部相关性。结果表明: 从区域发展的角度来看,长三角区域的发展协调性逐年增强。2010—2019年,上海市、苏州市等地区的经济发展、科教事业水平领先于其他城市,皖西北地区、舟山市、黄山市发展协调程度较弱。从空间自相关的角度来看,长三角区域各子系统平均自相关程度依次为人民生活>经济发展>资源环境>科教事业>基础建设。其中,经济发展与科教事业的全局莫兰指数呈下降趋势,科教事业没有呈现出显著相关性,基础建设的莫兰指数基本处于较低水平,不同年份浮动程度较大,人民生活在空间上具有明显的高-高与低-低集聚特征,资源环境的全局莫兰指数呈现“V”字形分布。经济建设和科教事业是与区域协调发展相关性最强的两种因素。 相似文献
3.
中国沿海省区海洋绿色发展测度及影响机理 总被引:1,自引:0,他引:1
海洋绿色发展是海洋高质量发展的重要内容,坚持生态优先和资源可持续的绿色发展模式对于海洋可持续的意义重大。在梳理了海洋绿色发展概念与内涵基础上,以沿海11省市为研究对象,基于2006-2017年沿海各省市的面板数据,建立海洋绿色发展评价指标体系,通过可变模糊识别模型对海洋绿色发展水平进行测度,并运用Arcgis软件和马尔可夫空间模型对其进行时空演变分析,最后运用面板数据模型进行影响因素分析。结果表明:①2006-2017年我国海洋绿色发展水平一直保持增长趋势,总体提高了19.6%,但整体仍呈中等水平,且地区差异明显。在空间分布上,空间集聚特征依然明显,东南沿海地区总体海洋绿色发展水平相对较高,西南和东北部分地区海洋绿色发展水平相对较低。②从时空演化特征来看,上海、天津、山东的海洋绿色发展水平相对较高,河北、广西的海洋绿色发展水平相对较低。区域背景对海洋绿色发展类型转移具有显著影响,高水平区域背景对海洋绿色发展水平增长具有辐射、促进作用,而低水平区域背景对增长具有制约、减缓作用。③从外部因素来看,政府调控、陆域经济水平和开放程度对海洋绿色发展有正向显著影响,环境治理有负向显著影响;从内部因素来看,海洋产业结构、海洋管理和海洋资源利用都有正向显著影响。根据总结以上结论,针对不同地区的海洋绿色发展情况提出不同的发展途径与对策,为海洋绿色发展提供科学的参考依据。 相似文献
4.
Fernando L. Cônsoli & S. Bradleigh Vinson 《Entomologia Experimentalis et Applicata》2004,112(1):47-55
Manipulation studies of the temporal availability of nutrients during parasitoid larval development (high‐quality host vs. host deprivation) demonstrated that parasitoid access to nutrition affected the wing morph development of Melittobia digitata Dahms (Hymenoptera: Eulophidae), but not the parasitoid's ovarian development. Around 70% of programmed short wing morph larvae (SWM) that had been host‐deprived at 120 h after host parasitization shifted their development and emerged as long wing morphs (LWM). A reversion in morph development of programmed LWM was also found when the larvae were offered new hosts after up to 120 h of development, and both programmed SWM or LWM larvae that differentiated as SWMs had a similar egg load. Although precocene treatment of programmed SWM induced 30% of LWM development, morph development of programmed LWM remained unaltered if treated with methoprene, a juvenile hormone analogue (JHA), indicating that the morph development of M. digitata does not appear to be under juvenile hormone control. However, both precocene and JHA affected the ovarian development of the emerging female. We hypothesize that specific nutrients from the host hemolymph, or changes in the host internal composition at the parasitoid larval sensitive stage (120–123 h) induce changes in pathways that control parasitoid metabolism and nutrient allocation decisions during the cell growth and development of imaginal discs. 相似文献
5.
Studies of development time of marine and freshwater copepods have taken separate tracks. Most studies on marine copepods report development time of each individual development stage, whereas studies on freshwater copepods report only development time, from egg to nauplius and nauplius to adult. This bias allows comparison of total development time but prevents detailed comparisons of patterns in stage-specific developmental schedules. With respect to egg to adult development time, three general relationships are known: developmental rates are dependent upon temperature and food concentration but independent of terminal body size; freshwater calanoids develop significantly slower than marine calanoids; freshwater cyclopoids develop at the same rate as marine calanoids. Two rules describe stage-specific developmental rates: the equiproportional rule and the isochronal rule. The first rule states that the duration of a given life history stage is a constant proportion of the embryonic development time; the second rule states that the time spent in each stage is the same for all stages. This review focuses on the second rule. From the 80+ published studies of copepod stage-specific developmental times, no species follows the isochronal rule strictly: Acartia spp. come closest with isochronal development from third nauplius (N3) to fourth copepodite (C4). The only pattern followed by all species is rapid development of the first and/or second naupliar stages, slow development of the second and/or third nauplius and prolonged development of the final copepodite stage. Once adulthood is reached, males are usually short-lived, but females can live for weeks to months in the laboratory. Adult longevity in the sea is, however, on the order of only a few days. The evolution of developmental patterns is discussed in the context of physiological constraints, along with consideration of possible relationships between stage-specific mortality rates and life history strategies. Physiological constraints may operate at critical bottlenecks in development (e.g. at the first feeding nauplius, N6, and the fifth copepodite stage). High mortality of eggs may explain why broadcast eggs hatch 2–3 times faster than eggs carried by females in a sac; high mortality of adults may explain why adults do not grow rather they maximize their reproductive effort by partitioning all energy for growth into egg production. 相似文献
6.
MicroRNA in cell differentiation and development 总被引:1,自引:0,他引:1
The regulation of gene expression by microRNAs (miRNAs) is a recently discovered pattern of gene regulation in animals and
plants. MiRNAs have been implicated in various aspects of animal development and cell differentiation, such as early embryonic
development, neuronal development, muscle development, and lymphocyte development, by the analysis of genetic deletions of
individual miRNAs in mammals. These studies show that miRNAs are key regulators in animal development and are potential causes
of human diseases. Here we review some recent discoveries about the functions of miRNAs in cell differentiation and development.
Supported by National Key Basic Research and Development Program of China (Grant No. 2005CB724602) and Knowledge Innovation
Project of the Chinese Academy of Sciences (Grant Nos. KSCX2-YW-R-096, KSCX1-YW-R-64) 相似文献
7.
Direct and indirect inhibition of Th1 development by progesterone and glucocorticoids. 总被引:13,自引:0,他引:13
Progesterone may contribute to the maternal suppression of immunity to the fetus by modulating the Th1/Th2 balance. To clarify whether progesterone directly or indirectly affects T cell differentiation, we used two experimental systems with isolated T cells in vitro. In one system, isolated CD4+CD8+thymocytes differentiated into Th1 and Th2 by two pulse stimulations with defined combinations of ionomycin and PMA followed by the treatment with IL-12, IL-4, and IL-2. In the second system, functional differentiation was induced in purified naive CD4 T cells with cytokines and Abs to CD3 and CD28. In both systems, progesterone added with cytokines suppressed Th1 development at concentrations associated with pregnancy, but enhanced the development of IL-10-producing Th2 cells. Because IL-10 is known to inhibit APC production of IL-12, Th1 development may be also suppressed indirectly by progesterone. However, progesterone failed to enhance IL-10 production in the absence of IL-12. The p38 mitogen-activated protein kinase (MAPK) inhibitor SB203580 inhibited Th1 development and enhanced Th2 development, as did progesterone, indicating that p38 MAPK and extracellular signal-regulated kinase pathways are involved in Th1 development. However, the progesterone effects may not be simply due to a modulation of MAPK activities, because the inhibitor did not significantly affect the development of IL-10-producing cells in the presence or absence of progesterone. Glucocorticoids exerted effects similar to those of progesterone on Th1/Th2 development even at lower concentrations. These results suggest that progesterone as well as glucocorticoids directly inhibit Th1 development and enhance Th2 development. 相似文献
8.
Hoover SE Higo HA Winston ML 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》2006,176(1):55-63
We examined the effect of larval and adult nutrition on worker honey bee (Apis mellifera L.) ovary development. Workers were fed high or low-pollen diets as larvae, and high or low-protein diets as adults. Workers
fed low-protein diets at both life stages had the lowest levels of ovary development, followed by those fed high-protein diets
as larvae and low- quality diets as adults, and then those fed diets poor in protein as larvae but high as adults. Workers
fed high-protein diets at both life stages had the highest levels of ovary development. The increases in ovary development
due to improved dietary protein in the larval and adult life stages were additive. Adult diet also had an effect on body mass.
The results demonstrate that both carry-over of larval reserves and nutrients acquired in the adult life stage are important
to ovary development in worker honey bees. Carry-over from larval development, however, appears to be less important to adult
fecundity than is adult nutrition. Seasonal trends in worker ovary development and mass were examined throughout the brood
rearing season. Worker ovary development was lowest in spring, highest in mid-summer, and intermediate in fall. 相似文献
9.
Judith A. Arcidiacono Steven R. Bauer David S. Kaplan Clare M. Allocca Sumona Sarkar Sheng Lin-Gibson 《Cytotherapy》2018,20(6):779-784
The development of standards for the field of regenerative medicine has been noted as a high priority by several road-mapping activities. Additionally, the U.S. Congress recognizes the importance of standards in the 21st Century Cure Act. Standards will help to accelerate and streamline cell and gene therapy product development, ensure the quality and consistency of processes and products, and facilitate their regulatory approval. Although there is general agreement for the need of additional standards for regenerative medicine products, a shared understanding of standards is required for real progress toward the development of standards to advance regenerative medicine. Here, we describe the roles of standards in regenerative medicine as well as the process for standards development and the interactions of different entities in the standards development process. Highlighted are recent coordinated efforts between the U.S. Food and Drug Administration and the National Institute of Standards and Technology to facilitate standards development and foster science that underpins standards development. 相似文献
10.
《Reproductive biology》2020,20(2):115-126
The development of primordial germ cells and gonads are determinants of reproductive health and fertility. Although the gonadal development process is similar for both genders, the gender-determining process and the mechanism of development of female and male gonads have different molecular mechanisms. Spermatogenesis and oogenesis are also included in this process for a healthy gonadal development. Many specific molecular signaling pathways play role in oogenesis and spermatogenesis and it is important to know at which stage these factors are effective, to understand the mechanism of a healthy gonadal development. With this review, we defined the importance of stage specific genes expressing during the events such as oogenesis and spermatogenesis with the prenatal and postnatal gonadal development. It will be important to know about the cellular signals involved in the control of the gonadal development. 相似文献
11.
以"人地协调"发展理念和"过程+格局+机制"思维范式为切入点,构建了基于DPSIR模型的绿色发展水平指标体系,运用熵权TOPSIS模型、障碍度模型和GIS空间可视化等方法对2008-2017年东北地区各城市的绿色发展水平时空分异特征与障碍因素进行实证研究。结果表明:①研究期内东北地区各城市绿色发展水平总体呈现从"小差距低水平"逐渐向"大差距高水平"转变的时序特征,空间分布大致呈现自北向南阶梯式递减的格局特征,且空间集聚效应显著。②东北地区各城市经济发展水平与绿色发展水平之间并非完全呈正相关关系,即,经济发展水平越高的城市,绿色发展水平不一定越高;而经济发展水平较低的城市,绿色发展反而达到较高的水平。这可能与区域资源环境承载力的大小有关。③东北地区各城市绿色发展水平时空分异的作用机制不尽相同,其中,资源禀赋条件、经济发展状况、政府投资规模在绿色发展水平的变化中起着重要的作用,同时也是导致东北地区绿色发展水平不同阶段呈现不同进化特征的主要原因。 相似文献
12.
生物技术与我国农业发展 总被引:2,自引:0,他引:2
从国际农业生物技术的发展趋势,看农业生物技术在现代中国农业发展中的重要地位和作用。分析了我国农业生物技术发展的现状和面临的挑战,提出在日益激烈的国际农业竞争环境中,我国农业生物技术的发展战略和措施 。 相似文献
13.
MicroRNA与动物发育 总被引:1,自引:0,他引:1
MicroRNA(miRNA)是一类约22nt大小的内源性非编码RNA,它们通过剪切靶基因的转录产物或者抑制转录产物的翻译从而起到转录后调控靶基因表达的作用。在动物体内,通过基因敲除等方法所进行的大量研究表明了miRNA参与了胚胎早期发育、脑及神经发育、心脏发育、肌肉及骨骼发育等动物发育的各个方面。miRNA是动物发生发育过程中重要的调控因子。主要介绍了近年来miRNA在动物生长发育过程中的研究进展。 相似文献
14.
小麦发育过程及生育期机理模型的研究I.建模的基本设想与模型的描述 总被引:34,自引:4,他引:30
将小麦发育的温度效应曲线化,以发育生理生态过程为基础,利用作物生理发育时间(Physiological Development Time,简称PDT)为尺度,提出系统地预测小麦顶端发育阶段和物候生育期的模拟模型.预测的顶端发育阶段包括单棱期、二棱期、小花原基分化期、雌雄蕊原基分化期、药隔期、四分体期、抽穗期.物候发育阶段包括种子萌发、出苗期、分蘖期、越冬期、返青期、拔节期、孕穗期、抽穗期、开花期、灌浆期、成熟期.模型中用来描述特定品种发育遗传差异的参数有温度敏感性、生理春化时间、光周期敏感性和基本早熟性,分别体现了不同品种小麦在热效应、春化作用、光周期反应以及最早开花时间这四方面的遗传特性,共同决定了不同品种到达各发育阶段的生理发育时间 相似文献
15.
16.
区域可持续发展SD规划模型的试验优控——以干旱区柴达木盆地为例 总被引:24,自引:0,他引:24
柴达木盆地作为我国下世纪重点开发地区之一,对其资源合理开发利用不仅对青海省经济发展有着举足轻重的作用,而且对缩小东西部发展差距、支援西藏、巩固国防有着不可估量的作用。以对盆地的实地考察为基础,运用SD模型对盆地资源开发和经济同生态环境协调发展弹性方案进行试验调控,得出追求经济发展为主目标的发展型方案、追求资源与生态环境保护为目标的保护型方案和追求人口、资源、环境和经济社会协调发展为主目标的协调型发 相似文献
17.
高等植物开花结实的多胺研究进展 总被引:1,自引:0,他引:1
多胺是广泛分布于植物体内具有调控作用的生理活性物质,其代谢变化与高等植物的 生长和发育关系密切。本文概述了多胺与植物花芽形成、花器官分化以及开花、坐果和果实发育的关系;并就外源多胺对植物开花坐果的影响做了述评,对多胺在植物开花结实中可能 的作用机理及今后的研究方向和应用潜力进行了讨论。 相似文献
18.
Diet and metabolic development 总被引:1,自引:0,他引:1
For many years, investigators have been concerned with mechanisms that control and alter genetically regulated development. An intriguing aspect of these mechanisms is the ability of environmental factors to induce certain metabolic processes. Animal studies have shown that dietary manipulation of cholesterol and fatty acid metabolism during development can have persistent and permanent effects. In addition, there appears to be a critical period when changes in the diet can have lasting consequences. The changes in the control exerted by nutritional factors on metabolic development coincide with three phases of development: prenatal, suckling, and weaning. The effects of diet on cholesterol and fatty acid metabolism throughout these three phases of development will be addressed in this review. 相似文献
19.
免疫疗法已被成功应用于多种肿瘤的治疗,显著提高患者的生存质量。免疫细胞疗法是当前免疫疗法研发的重点方向之一。免疫细胞疗法发展历经了由非特异性免疫到无差别化特异性免疫,再到差别化特异性免疫的发展阶段。免疫细胞疗法已有多个产品获批上市,产业体系初步成型,主要包括疗法/药物研发和相关服务/器材供应。通过梳理国内外免疫细胞疗法产业发展态势,分析免疫细胞疗法发展的技术瓶颈,找出我国发展该产业存在的主要问题,并提出发展建议,为我国发展免疫细胞疗法产业提供参考。 相似文献
20.
What was unique about our laboratory was the detailed simulation of a human rearing environment for infant chimpanzees, together
with continuous, intensive observation and recording of behavioral development. Communication in American Sign Language (ASL)
was integrated into this procedure in a way that simulates the teaching of vocal and gestural languages to human children.
The result is a comprehensive longitudinal record of the stage by stage development of two-way communication in sign language
and its relation to basic aspects of behavioral development such as: locomotion, manipulative skills, observational learning,
and social play.
In the longitudinal records of five infant chimpanzees, we can trace the patterns of development and also examine the consistency
of individual differences through the first five years. The central question is the relation between developing skills in
the use of American Sign Language and the rest of behavioral development. To analyze factors that influence development, we
have compared records for infant chimpanzees reared in the crossfostering laboratory with records for chimpanzees reared in
the wild by their own mothers and chimpanzees reared in cages under conventional laboratory conditions, as well as with records
of development for human children, reared in homes and reared in institutions. 相似文献