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1.
ABSTRACT Cities and metropolitan regions face several challenges including urban sprawl, auto dependence and congestion, and related environmental and human health effects. Examining the spatial characteristics of daily household activity‐travel behavior holds important implications for understanding and addressing urban transportation issues. Research of this sort can inform development of urban land use policy that encourages the use of local opportunities, potentially leading to reduced motorized travel. This article examines the potential household activity‐travel response to a planned metropolitan polycentric hierarchy of activity centers. Behavioral observations have been drawn from an activity‐travel survey conducted in the Portland, Oregon, metropolitan area during the mid‐1990s. Evidence presented from exploratory analysis indicates an urban/suburban differential, with less daily travel and smaller activity spaces for urban households. Investigation of the travel reduction potential of the proposed land‐use strategy suggests that location effects could be offset by adjustments to household sociodemographic and mobility characteristics.  相似文献   

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Over the past decade, M‐type cytoplasmic male sterility (CMS) line W931A and a variety of restorer lines have been exploited for the release of hybrid seeds in soybean (Glycine max). However, the identities of restorer genes in the nuclei of soybean restorer lines are still unclear. In this study, we analysed the inheritance pattern of restorer locus Rf‐m from restorer line WR016 and constructed a high‐resolution map of this locus. Results showed that Rf‐m in WR016 is a monogenic dominant gene located within a 162.4‐kb region on chromosome 16, which is flanked on each side by new developed simple sequence repeat (SSR) markers GmSSR1602 and GmSSR1610 at a distance of 0.11 and 0.25 cM, respectively. Nineteen open reading frames (ORFs) were predicted in this region. Of these, seven genes arranged in tandem on chromosome 16 encode pentatricopeptide repeat (PPR) proteins, which is similar to other reported restorer loci in plants. These results lay a solid foundation for map‐based cloning of the Rf‐m gene and will be helpful for marker‐assisted selection of elite CMS restorer lines.  相似文献   

4.
Numerous scholars studying community efforts to (re‐)establish autonomy have begun to focus on the importance of empowerment in the economic, political and cultural spheres. There is a growing understanding that such empowerment can be hastened by affirmative development strategies that build on community assets and capacities rather than attempting to redress – and thereby emphasising – needs or lack. Such development work reflects intertwined currents in contemporary philosophy, influenced by the thought of Friedrich Nietzsche and of Gilles Deleuze. In Taiwan, a recent resurgence in identities among marginalised aboriginal or indigenous peoples (‘Formosans’) has been accompanied by novel approaches to development. This discussion heuristically employs a set of development theories that are essentially variants of ‘asset‐based community development’ (ABCD) to suggest that a focus on affirmation and empowerment has been and can be a key to success in Formosan development initiatives. The paper presents the results of qualitative field research, illuminating three case studies of Formosan development – in Tsou, Tayal and Taroko territories. It argues that Formosan development will benefit from a focus on community capacity, political empowerment and social as well as physical assets, and that to an important degree this has already happened in some communities.  相似文献   

5.
Mega‐city regions (MCRs) have emerged as the main spatial form of China's new urbanization strategy and become the basic spatial units participating in global and regional competition. However, MCRs are not equally capable of boosting regional economic development due to their different levels of development. Therefore, this paper adopts the concept of competitiveness as both a theoretical framework and an empirical model to evaluate the development status of China's MCRs. Based on a review of the existing literature, this paper proposes a multi‐tier evaluation system to calculate the competitiveness of 13 MCRs. The chosen indicators come from the six perspectives of economic development, human resources, infrastructural accessibility, integration into the global economy, capacity for scientific and technological innovation, and sustainable development. The results show that there are great disparities and regional inequalities in competitiveness across different MCRs. The Yangtze River Delta, Pearl River Delta, and Beijing–Tianjin–Tangshan MCRs are the first‐tier MCRs with the highest levels of development and have significant global influence as well. Chengdu–Chongqing, Shandong Peninsula, South‐central Liaoning, and Wuhan belong to the second‐tier of MCRs that show partial advantages and have significant regional influence. The remaining regions belong to the third‐ or fourth‐tier of MCRs that have relatively weak competitiveness. The competitiveness of MCRs largely depends on the concentration of core elements in core cities.  相似文献   

6.
Soybean (Glycine max [L.] Merr.) cultivars are generally sensitive to flooding stress. The plant growth is severely affected and grain yield is largely reduced in the flooded field. It is important to develop flood‐tolerant soybean cultivars for grain production in regions of heavy rainfalls worldwide. In this study, a total of 722 soybean genotypes were evaluated for flooding tolerance at R1 stages (first flower at any node) in the 5‐year flooding screening tests. Differential soybean genotypes exhibited diverse responses to flooding stress with that plant foliar damage score (FDS) and plant survival rate (PSR) ranged from 1.9 to 8.8 and 3.4% to 81.7%, respectively (p < .0001). Based on our standard of flooding evaluation, most genotypes were sensitive to flooding with 6.0 of average FDS and 38.7% of PSR. Fifty‐two soybean genotypes showed flooding tolerance and 11 genotypes were with consistent flooding tolerance during 4‐ to 5‐year continual evaluations. In the meantime, six genotypes were identified with consistent high sensitivity to flooding. The group analysis showed that genotypes from different sources had distinguishable responses to flooding stress (p < .0001). The interacting analysis of year and flooding tolerance indicated that FDS and PSR means were significantly different among 5 years due to weather temperature and flooding treatment time influences of each year (p < .0001). Furthermore, five breeding lines with high‐yielding and flood‐tolerant traits were developed using selected consistent flood‐tolerant and high‐yielding genotypes through conventional breeding approach.  相似文献   

7.
着装行为通过影响室内空气参数的设定而影响建筑空调能耗。利用能耗模拟软件DeST,计算出该地区典型着装行为下实测运行参数与期望参数对应的建筑空调能耗比推荐标准下能耗分别降低了10.86%和13.16%。而基于典型着装行为的实验热学性能参数下,平均只降低4%,说明由着装热阻关联的主观温度需要按地区着装行为进行修正。提出了控制建筑空调能耗的着装行为调节模型,着装行为节能率εc为负值时节能,为正值时不节能。京津地区办公建筑节能率为0的临界服装热阻为0.563 clo,空调系统设计和运行节能的前提是,着装热阻低于临界值。着装行为调节模型为地区着装形式和着装面料提供了量化标准,为精确控制建筑能耗提供了一种方法。  相似文献   

8.
Over the past three decades, we have seen a flourishing of scholarship which explores the emerging political spaces and variegated scales of governance in China. This research draws on political economic tradition to argue that the way in which cities and regions are governed is indeed infused with socio‐political struggles which are proliferating at a range of spatial scales. Such theoretical interpretation is illuminating, but it has been subject to increasing criticism from the poststructuralist approach that views scale as an epistemological construct. This paper uses the Pearl River Delta Intercity Railway System (PRD‐ICRS) as a case study to challenge the onesidedness of both the political economy tradition and the poststructuralist approach in reading scale. It employs the “scale politics” thesis to argue that scale is more than a material existence (or institutionalised structure) that represents a particular arrangement of political power, being subject to perpetual transformation through regulatory projects and strategies. It is also a “representation trope” deployed in political discourses to acquire persuasive power to frame and legitimise these projects and strategies. Scale is thus both material and discursive. Understanding the two moments of scale enables a fuller dissection of political transformation.  相似文献   

9.
Vivek Maize Hybrid 9‐ a popular single‐cross hybrid developed by crossing CM 212 and CM 145 was released for commercial cultivation in India. The parental lines, being deficient in lysine and tryptophan, were selected for introgression of opaque‐2 allele using CML 180 and CML 170 as donor lines through marker‐assisted backcross breeding. The opaque‐2 homozygous recessive genotypes with >90% recovery of the recurrent parent genome were selected in BC2F2, and the seeds with <25% opaqueness in BC2F3 were forwarded for seed multiplication. Vivek Quality Protein Maize (QPM) 9, the improved QPM hybrid, showed 41% increase in tryptophan and 30% increase in lysine over the original hybrid. The grain yield of the improved hybrid was on par with the original hybrid. The newly improved QPM maize hybrid released in 2008 will help in reducing the protein malnutrition because its biological value is superior over the normal maize hybrids. This short duration QPM maize hybrid has been adopted in several hill states of North Western and North Eastern Himalayan regions.  相似文献   

10.
Emerging post‐development literatures consider how post‐structural and post‐colonial critiques of development could form the basis for new kinds of development practices. Much of the search for such post‐development possibilities draws on new theories of discourse. This paper considers the challenges of bringing together empirical research and the experience of doing development with the often ethereal and deeply speculative work of discourse theorists. I reflect on the course taken by my own research in Northern Thailand, and discuss the possibilities that can emerge as theory confronts empirics, and conceptual frameworks are transformed through the daily politics of fieldwork.  相似文献   

11.
This case study investigates the complex ways that recurrent ecological damage affected the course of socio‐economic development on Niue Island, a Pacific micro‐state. In tracing the historical record of droughts and hurricanes from 1900 to 1990, it is clear that severely inclement weather repeatedly destroyed agricultural development endeavours on the island leading to stagnation in this economic sector. In the aftermath of such disasters there were additional widespread social, political, and economic responses resulting in insidious but inexorable change. These responses – metaphoric ‘winds of change’– constituted, bolstered and sustained the transition to a MIRAB economy.  相似文献   

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Development of effective molecular markers linked to Pm21 deriving from Haynaldia villosa is critical for wheat breeding of powdery mildew resistance. In this study, we designed 12 pairs of conserved‐intron scanning primers (CISPs), using intron‐containing conserved genes located on the short arm of Brachypodium distachyon chromosome 3 (3BdS) aligned with cDNA or expressed sequence tags (ESTs) of Triticeae crops. Of 12 CISP primer pairs, 11 amplified DNA both in H. villosa and in wheat, and four displayed H. villosa chromosome 6VS‐specific polymorphisms. Six non‐polymorphic DNAs were further sequenced for designing internal primers, and five additional 6VS‐specific markers were obtained. Of the total nine 6VS‐specific co‐dominant markers, six could effectively trace Pm21 in F2 population derived from the hybrid between the T6AL.6VS line and ‘Yangmai 158’. This study demonstrated that Brachypodium genomic information could be powerfully utilized to develop molecular markers in H. villosa or other Triticeae species.  相似文献   

14.
As the urban world population grows steadily, cities have become the main habitat for human beings. Against this backdrop, city quality or the level of development of the city's habitat that ensures the satisfaction of objective and subjective human needs become a matter of growing interest and concern for academics, policy makers, and citizens. Building on a resource‐based view of city quality, the aim of this paper is twofold. First, it proposes and validates scales for six city sub‐habitats: political, economic, social, natural, artificial, and technological. Second, it tests a model and the underlying hypothesis about the ranking of those sub‐habitats and of the perceived controversy regarding decision making upon them. For those purposes, a survey of 768 city inhabitants was conducted in Portugal to measure city quality and their sub‐habitats. Both the predicted ranking of importance of the sub‐habitats and the perceived ranking of controversy were empirically validated. The results constitute a novel and important contribution to understand city quality and its sub‐habitats, whose conceptual power relies on hierarchized factors linked to citizens’ happiness and to the level of controversy of the solutions.  相似文献   

15.
Barley (Hordeum vulgare) is an important component of heart‐healthy whole grain diets because it contains β‐glucan. All current US barley varieties with high β‐glucan are spring habit and have waxy starch. Winter varieties have agronomic advantages but require low‐temperature tolerance (LTT). Vernalization sensitivity (VS) is associated with higher levels of LTT. To rapidly develop fall‐sown varieties with LTT and higher grain β‐glucan, we therefore used marker‐assisted selection (MAS) at the WX and VRN‐H2 loci. The MAS‐derived lines, together with unrelated non‐waxy germplasm developed via phenotypic selection (PS), were used for a genome‐wide association scan (GWAS). The panel was phenotyped for grain β‐glucan, LTT and VS. It was genotyped with 3072 single‐nucleotide polymorphisms (SNPs) and allele‐specific primers. Marker‐assisted selection fixed target alleles at both loci but only one of the target phenotypes (higher β‐glucan percentage) was achieved. Variation for VS and LTT is attributable to (i) incomplete information about VRN‐H1 at the outset of the project and (ii) unexpected allelic variation at VRN‐H3 with a large effect on VS and LTT.  相似文献   

16.
The realisation that climate change might necessitate resettlement of people displaced initially raised interest in the experience of development‐forced displacement and resettlement (DFDR). Looking back, in 1980 the first international policy on involuntary resettlement was approved to address perceived weaknesses in state property and expropriation law to safeguard people in the way of development projects. Since then international policy and praxis have brought global attention to developmentally displaced people but have not guaranteed them an effective safeguard. Recently, renewed attention has focussed on state legal and governance frameworks substantively and procedurally. Identifying four key policy objectives that resonate with climate change displacement I analyse their treatment in a data base of DFDR laws and regulations from 40 Asia Pacific states. This analysis finds overall little legal congruence. Innovative new formulations in some Asian state laws address recent public criticisms and research findings, but mostly are yet to demonstrate positive outcomes for displaced people. Pacific states increasingly abandon expropriation law to negotiate lease terms for public infrastructure projects with customary landowners that do not extinguish customary title. Any laws governing climate change relocations must protect rights, livelihoods, well‐being, inclusive decision‐making and community initiatives with procedures whilst not relinquishing climate‐change‐reducing action.  相似文献   

17.
双季稻地区发展一季稻存在的问题及解决措施   总被引:1,自引:0,他引:1  
湖南省是典型的双季稻区,水稻常年播种面积400万hm~2,稻谷总产2500万t左右,随着种植业结构的进一步调整,全省双季稻面积逐年减少,而一季稻(包括中稻和一季晚稻)面积逐年增加,  相似文献   

18.
A genetic linkage map of walnut containing 2,220 single nucleotide polymorphisms (SNPs) in 16 linkage groups (LGs) was constructed using an F1 mapping population from a cross between “Chandler” and “Idaho,” two contrasting heterozygous parents. Five quantitative yield traits, lateral fruitfulness, harvest date and three nut traits (shell thickness, nut weight and kernel fill) were then mapped on to linkage groups. A significant quantitative trait locus (QTL) in LG 11 with negative additive effects suggested heterozygote superiority in the expression of lateral bearing. A set of three QTLs explaining ~10% of the variation in harvest date was located in LG 1. Shell thickness, nut weight and kernel fill were under the control of two to three linked pleiotropic QTLs in LG 1 segregating from “Idaho.” The marginal positive additive effects of QTLs for harvest date, shell thickness and nut weight and small negative additive effects for kernel fill suggested that the QTLs had a marginal effect on the expression of these traits.  相似文献   

19.
The effects of elevated concentrations of atmospheric CO2 (e[CO2]) on the nutritive value of wheat vegetative matter and grain as a feedstock for ruminants were investigated in a study undertaken at the Australian grains free‐air CO2 enrichment (AGFACE) facility. The study included two commercial wheat cultivars (Janz and Yitpi) and two genetic selections from a Seri/Babex population (SB003 and SB062) which had previously been characterised for low and high water‐soluble carbohydrate accumulation efficiency. The trial was grown under ambient (~390 µmol/mol) and elevated (~550 µmol/mol) CO2 conditions, and plants harvested at tillering, anthesis and physiological maturity. Composition analyses to determine the nutritive value for ruminant feed were undertaken on stems, leaves and grain. Plant and grain nitrogen were reduced in the e[CO2] treatments, and as expected, the water‐soluble carbohydrates increased. All genotypes responded to e[CO2] with the effects of altered composition evident within 60 days of sowing. Determinants of ruminant feed quality such as neutral and acid detergent fibre and estimated in vitro metabolisable energy were not significantly affected. The reduced plant and grain N will impact on the nutritive value and supplementation may be required. The impact of e[CO2] on chemical composition of wheat plants may be greater if the predicted climate change is associated with concomitant abiotic stress such as high ambient temperature or low soil moisture.  相似文献   

20.
Lacking of reference genome sequence for the development of stable molecular markers for specific chromosomes (intervals) remains to be a challenge in cotton, which was a necessary step in fine mapping of gene (QTL). In this study, the feasibility of development of single‐nucleotide polymorphism (SNP) markers between CS‐B14Sh (a substitution line for short arm of Chromosome 14) and TM‐1 (the recurrent parent) was explored using next‐generation sequencing (NGS) based on reduced representation libraries (RRLs). High‐quality genome sequences, representing about 7.1%, 8.8% and 10.4% of the tetraploid cotton genome, were generated for TM‐1, 3‐79 (the donor parent) and CS‐B14Sh, respectively. A total of 397 putative SNP markers were detected between CS‐B14Sh and TM‐1, and most (358) of them were also detected between TM‐1 and 3‐79. Allele‐specific PCR method was used for validation of 40 SNP markers, and 27 of them showed polymorphism between TM‐1 and CS‐B14Sh, and a linkage group comprising of 25 SNP markers and five SSR markers was constructed. The order of SNP markers agreed well with the position of them on Chr05 of D genome, which further approved the truth of SNPs detected. The results suggested that the development of SNP markers in specific genome region using NGS was efficient in substitution or near‐isogenic lines.  相似文献   

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