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1.
Urban greenspace benefits urbanites in numerous ways ranging from regulating flooding, air quality, and local climate to providing opportunities for exercise and relaxation. These benefits may influence human health. Greenspace, for example, may facilitate exercise, thereby helping to reduce body mass index (BMI) and combat obesity, a current epidemic of great public health concern. Little evidence exists to support this assertion, however, and we lack a full understanding of the mechanisms whereby this relationship operates, the populations for whom greenspace is linked to weight status, and the aspects of urban greenspace that are linked to weight status. This study seeks to identify relationships among the composition and arrangement of greenspace and BMI for different populations using regression models for eight age and gender groups in Cleveland, Ohio, US. We find that several greenspace variables are related to BMI for women under 65 years and males under 51 years, but not for older groups, and that the aspects and types of greenspace that are significantly related to BMI vary among groups. Relationships between greenspace attributes and BMI are generally stronger for female groups and for younger groups. Providing access to greenspace with particular attributes such as greenspaces with water, canopy cover, or connected greenspaces could support a healthy weight status for some populations, but these attributes are not consistent across age and gender groups. These results could help to inform policy aimed at designing urban greenspace to benefit the health of different population subgroups. 相似文献
2.
本文在对会泽近几年乐业辣椒的生产发展情况进行调查的基础上,结合当地农业结构调整,从科学发展观的角度,提出做大会泽辣椒产业的对策措施.主要内容包括运用现代科学技术手段,实行乐业辣椒标准化生产,提高单位面积的产量和产品的质量,确保达到国家无公害农产品的要求;健全服务体系,扶持龙头企业和各种营销组织,实施品牌战略,提高乐业辣椒的知名度和市场占有率等等. 相似文献
3.
Asheesh Shanker Aarti BhargavaRicha Bajpai Stuti SinghSucharita Srivastava Vinay Sharma 《Scientia Horticulturae》2007
Characterization of microsatellites is extremely important for the development of molecular markers. Here, we present the detection and abundance of microsatellites or simple sequence repeats (SSRs) in UniGene sequences of Citrus sinensis. A total of 427 SSRs were mined in 8786 UniGene sequences downloaded from National Center for Biotechnology Information (NCBI). Depending on the repeat units, the length of SSRs ranged from 14 to 21 for mono-, 14 to 48 for di-, 18 to 48 for tri-, 24 to 40 for tetra- and 42 bp for hexa-nucleotide repeats. Average density of SSRs (1SSR/12.92 kb of 5518.71 kb sequences mined) suggests that only 4.43% of sequences contained SSRs. Di-nucleotide repeats were most frequent repeat type (49.41%) followed by tri-nucleotide repeats (41.45%). An attempt was made to design primer pairs for 427 identified SSRs but these were found only for 216 sequences. The positions of SSRs with respect to open reading frame (ORF) detected and annotation of sequences containing SSRs were also carried out to assign function to each of the sequences. 相似文献
4.
ABSTRACT: Recent progress in cassava transformation has allowed the robust production of transgenic cassava even under suboptimal plant tissue culture conditions. The transformation protocol has so far been used mostly for the cassava model cultivar 60444 because of its good regeneration capacity of embryogenic tissues. However, for deployment and adoption of transgenic cassava in the field it is important to develop robust transformation methods for farmer- and industry-preferred landraces and cultivars. Because dynamics of multiplication and regeneration of embryogenic tissues differ between cassava genotypes, it was necessary to adapt the efficient cv. 60444 transformation protocol to genotypes that are more recalcitrant to transformation. Here we demonstrate that an improved cassava transformation protocol for cv. 60444 could be successfully modified for production of transgenic farmer-preferred cassava landraces. The modified transformation method reports on procedures for optimization and is likely transferable to other cassava genotypes reportedly recalcitrant to transformation provided production of high quality FEC. Because the three farmer-preferred cassava landraces selected in this study have been identified as resistant or tolerant to cassava mosaic disease (CMD), the adapted protocol will be essential to mobilize improved traits into cassava genotypes suitable for regions where CMD limits production. 相似文献
5.
AIM: To investigate whether cigarette smoke (CS) promotes the expression of endoplasmic reticulum-associated apoptosis protein CCAAT/enhancer-binding protein homologous protein (CHOP) in rat lung tissues.METHODS: Adult male Wistar rats (n=40) were randomly divided into 4 groups with 10 rats in each group:control group, CS-2 group (exposed to CS for 2 months), CS-4 group (exposed to CS for 4 months) and ex-smoking (Ex-S) group (exposed to CS for 4 months and then quit smoking for 1 month). The percentage of forced expiratory volume in 0.3 second to forced vital capacity (FEV0.3/FVC) and peak expiratory flow (PEF) were measured. TUNEL assay was used to detect the apoptotic cells. In situ hybridization and RT-PCR were used to determine the mRNA expression of CHOP. The methods of immunohistochemistry and Western blot were used to determine the protein expression of CHOP. Western blot was also used to determine the protein levels of protein kinase R-like endoplasmic reticulum kinase (PERK), p-PERK, eukaryotic initiation factor (eIF) 2α and p-eIF2α.RESULTS: The pulmonary function greatly decreased in the rats exposed to CS for 2 months in comparison with control group (P<0.05), markedly decreased in the rats exposed to CS for 4 months as compared with the rats after exposure to CS for 2 months (P<0.05), and was improved little in ex-smoking rats (P>0.05). The structural destruction of the lung was observed in the rats exposed to CS for 2 months, and more obvious changes were found in the rats exposed to CS for 4 months. However, the structural destruction of the lung remained obvious in ex-smoking rats. The apoptotic cells were markedly increased in the rats exposed to CS for 2 months and were even more in the rats exposed to CS for 4 months. The apoptotic cells were alveolar epithelial cell I (ACE I), ACE Ⅱ, vascular endothelial cells and bronchial epithelial cells. The protein levels of p-PERK, p-eIF2α and CHOP were remarkably increased in the rats after exposure to CS for 2 months compared with the control rats (P<0.05), significantly elevated in the rats exposed to CS for 4 months compared with the rats exposed to CS for 2 months (P<0.05), and slightly decreased in ex-smoking rats in comparison with the rats after exposure to CS for 4 months (P>0.05). The total protein levels of PERK and eIF2α did not change between the control rats and those exposed to CS.CONCLUSION: CS promotes the development of chronic obstructive pulmonary disease (COPD) by inducing the expression of endoplasmic reticulum-associated apoptosis protein CHOP via PERK/eIF2α/CHOP signaling pathway. 相似文献
6.
Urban green spaces (UGS) are increasingly acknowledged for their importance for the well-being of urban populations. However, studies are lacking the consideration of the demand and use of UGS by different population groups and connecting UGS with social infrastructure. In an era of worldwide urbanization and ageing, this European study sheds light on the role of UGS for care facilities for elderly. 126 care facilities from 17 cities in Austria, Germany, Norway, Poland, Romania and Slovenia took part in an online survey. Administrations of care facilities gave insights on the (1) importance of gardens related to care facilities for the quality of life for the seniors, (2) importance of UGS outside of care facilities for the quality of life for the seniors and (3) the consideration of natural and age-friendly designs and management of ecosystem disservices of UGS. The results emphasize not only the importance of UGS for the quality of life of seniors residing in care facilities, but also for the staff and visitors. UGS contribute to physical activities, recreation, and social interactions. The study found that in particular facilities with an own garden are highly aware of the benefits UGS provide. The study holds important lessons for UGS planning, management and design not only to focus on the quantitative supply of UGS, but also to consider age-sensitive amenities in and access to UGS of high quality for seniors. 相似文献
7.
47份鲜食玉米对丝黑穗病和瘤黑粉病的抗性鉴定与评价 总被引：1，自引：0，他引：1
2018年通过田间人工接种对47份鲜食玉米杂交种进行了由丝孢堆黑粉菌(Sporisorium reilianum)引起的玉米丝黑穗病和玉蜀黍黑粉菌(Ustilago maydis)引起的玉米瘤黑粉病的抗性鉴定和评价。对丝黑穗病的鉴定结果表明,47份鲜食玉米杂交种中无高抗材料;4份材料表现抗病,分别是三禾甜加糯6号、金辉588、金辉895和黑甜糯520,占8.5%;1份材料盛彩甜3号表现中抗,占2.1%;14份材料表现感病,占29.8%;28份材料表现高感,占59.6%。对瘤黑粉病的鉴定结果表明,47份鲜食玉米杂交种中27份材料表现高抗,占57.4%;6份材料表现抗病,占12.8%;6份材料表现中抗,占12.8%;5份材料表现感病,占10.6%;3份材料表现高感,占6.4%。鲜食玉米新品种中抗丝黑穗病品种比较匮乏,抗瘤黑粉病品种比较丰富,但兼抗两种病害的品种严重缺乏。 相似文献
8.
为进一步壮大预制菜市场规模、促进预制菜消费需求不断增长,对北京市1085位居民消费者的调研结果进行数据分析,结果发现：绝大多数消费者对预制菜有所了解,了解的主要渠道为线下广告/试吃或网络推广,了解预制菜的消费者中青年消费者群体购买意愿偏高;不同年龄的消费群体对预制菜口味有着不同的偏好与要求,麻辣鲜香口味的预制菜总体上更受欢迎,并且消费者对口味的偏好随着年龄的增长逐渐偏向于清淡;大多数消费者偶尔购买预制菜,在消费者消费预制菜的情景上,工作与疫情影响更大;电商渠道和连锁超市渠道是消费者购买预制菜的主要渠道。通过二元选择模型研究分析消费者个人特征对预制菜消费的影响,发现消费者年龄、职业和在家烹饪频率对预制菜消费有显著影响,40周岁以下的年轻人、学生和企业员工、每周在家烹饪3次以上的消费者购买预制菜的倾向更高。通过主成分分析及聚类分析方法,对消费者预制菜购买动机及其选择结果进行分析,发现追求方便快捷型的消费者口味偏向于麻辣,购买预制菜多用于节日聚餐,购买渠道多为连锁超市和农贸市场;追求性价比型的消费者口味偏向于清淡、麻辣,购买预制菜多用于节日聚餐、送人,购买渠道多为农贸市场;追求安全型的消费者... 相似文献
9.
Urban greenspaces are multifunctional spaces, providing services to people and biodiversity. With space in urban areas being limited creation and maintenance of urban greenspaces relies on understanding the preferences of urban residents for their characteristics. Such preferences are expected to vary with current availability, and the availability of alternatives to greenspaces such as gardens or gyms. We carried out a nationwide discrete choice experiment with Scottish urban residents to estimate values associated with greenspace attributes of: recreational features; plants and natural features; trees; accessibility; time to walk from home and size, to test the hypotheses that: (i) people are willing to pay to maintain greenspace, (ii) people have willingness to pay for greenspaces with multiple functions, including features for direct use (e.g. play equipment) and biodiversity (e.g. wildflowers), (iii) willingness to pay for individual greenspace will vary according to socioeconomic characteristics and (iv) vary with the amount of greenspace or substitute facilities available. We find a positive willingness to pay to maintain greenspace in general, and higher willingness to pay for larger greenspaces closer to home, which are multifunctional and contain both direct use features (e.g. children’s play park) and biodiversity features. Although we find significant heterogeneity in willingness to pay for maintaining greenspace, this is not well explained by either socioeconomic characteristics or the availability of substitute facilities. Our results have relevance for urban natural capital accounting, and demonstrate to urban planners the importance of the design and maintenance of multi-functional greenspaces for urban populations and would benefit from future research that further explores heterogeneity, including perceptions of greenspace access and substitutes, and greenspace quality. 相似文献
10.
Urban sprawl is a major driving force of land use change. To develop strategies for sustainable urban development, planners need suitable indicators, one of which is the quality and quantity of green spaces in a city. To implement conservation strategies for urban areas, an assessment of how people perceive green spaces is required. The aim of this paper is to analyze: (1) willingness to contribute financially to two types of urban green spaces, (2) how people's attitudinal and socio-economic characteristics affect this willingness, and (3) to what extent this willingness is affected by the information that green spaces are important for avifauna conservation. We found that 72% of the respondents in Montpellier, France preferred natural (versus ornamental) green spaces and wanted them to be increased in the city. To achieve this, 52% of the respondents were willing to pay a percentage of their monthly household income. Giving information about birds to residents increased their preferences (especially for those having a “favourable” attitude for urban fauna) for “natural” green spaces and increased willingness to pay for green spaces among people using green spaces at least monthly. For people less concerned about nature, there was no such effect of providing bird information on preferences for green spaces. 相似文献
11.
Urban forests provide opportunities for outdoor recreation to many people. Knowledge of the motives for visiting forests is needed for the planning and management of these forests. Since forests are used for a diverse set of recreational activities, however, the motives for different activities are multifaceted. To explore recreational motives, this scene preference study conducted in Sweden examined relations between setting evaluations (i.e., mystery, legibility, valence, and activation), setting preference, general forest perceptions, and intention to engage in forest activities. Two alternative models were examined in relation to five different activities: walking, going on outings, exercising, picking berries or mushrooms, and studying plants and animals. Results revealed that preference mediated between setting evaluations and intention to go on outings, whereas setting evaluations were direct predictors of intention to walk and exercise. However, the models did not describe antecedents of intention to pick berries or mushrooms, or to study plants and animals, satisfactorily. In addition, general forest perceptions, particularly emphasising the restorative qualities of forests, were important for intention to engage in all the examined recreation activities. Results are discussed in relation to landscape preference research and attitude-behaviour theory. In addition, practical implications for encouraging forest recreation are highlighted. 相似文献
12.
Following the increasing public health concerns related to physical inactivity in the population, the relationship between outdoor recreation and public health has been increasingly acknowledged over the last decades. To improve public health, planners and policy-makers aim to provide good accessibility to recreational landscapes to facilitate outdoor recreational activity. At the same time, they are facing development pressure due to urban growth. In order for planners and policy-makers to secure people access to urban and near urban recreational areas, there is a need to map and measure access in a way that is adequate as a basis for decision-making in planning and design processes. Access is often defined as distance, or proximity, from residents’ homes to recreational areas. This paper explores different ways to map and measure distance to recreational areas, and aims to provide better decision support for planners and decision-makers. Moss municipality in Norway serves as a case study. We begin by addressing the meaning of the term ‘recreational landscape’ and how the choice of definition affects the results when mapping recreational areas. We also discuss who we are measuring distance for, and how different user groups will have different thresholds or critical distances affecting their frequency of visits to a recreational area. Last, we explore different methods for measuring distance within a GIS environment. The paper shows how the purpose of the analysis must be decisive when defining recreational landscapes and choosing methods for measuring access to recreational landscape, in order to provide valuable input to planners and policy-makers aiming at enhancing the possibility for outdoor recreation for people. 相似文献
13.
Using normative scenarios in landscape ecology 总被引：1，自引：1，他引：1
The normative landscape scenario is one of many types of scenario methods that are used by landscape ecologists. We describe how normative landscape scenarios are different from other types and how these differences create special potential for engaging science to build landscape policy and for exploring scientific questions in realistic simulated landscapes. We describe criteria and a method for generating normative scenarios to realize this potential in both policy and landscape ecology research. Finally, we describe how the method and criteria apply to an interdisciplinary project that proposed alternative scenarios for federal agricultural policy and related futures for agricultural watersheds in Iowa, USA.This revised version was published online in May 2005 with corrections to the Cover Date. 相似文献
14.
How should we measure landscape connectivity? 总被引：9，自引：0，他引：9
The methods for measuring landscape connectivity have never been compared or tested for their responses to habitat fragmentation. We simulated movement, mortality and boundary reactions across a wide range of landscape structures to analyze the response of landscape connectivity measures to habitat fragmentation. Landscape connectivity was measured as either dispersal success or search time, based on immigration into all habitat patches in the landscape. Both measures indicated higher connectivity in more fragmented landscapes, a potential for problematic conclusions for conservation plans. We introduce cell immigration as a new measure for landscape connectivity. Cell immigration is the rate of immigration into equal-sized habitat cells in the landscape. It includes both within- and between-patch movement, and shows a negative response to habitat fragmentation. This complies with intuition and existing theoretical work. This method for measuring connectivity is highly robust to reductions in sample size (i.e., number of habitat cells included in the estimate), and we hypothesize that it therefore should be amenable to use in empirical studies. The connectivity measures were weakly correlated to each other and are therefore generally not comparable. We also tested immigration into a single patch as an index of connectivity by comparing it to cell immigration over the landscape. This is essentially a comparison between patch-scale and landscape-scale measurement, and revealed some potential for patch immigration to predict connectivity at the landscape scale. However, this relationship depends on the size of the single patch, the dispersal characteristics of the species, and the amount of habitat in the landscape. We conclude that the response of connectivity measures to habitat fragmentation should be understood before deriving conclusions for conservation management. 相似文献
15.
苹果试管染色体组工程育种 总被引：7，自引：0，他引：7
用秋水仙０．４％和０．８％的浓度，诱变苹果７个二倍品种自然授粉的胚，通过试管培养，抑制胚芽成梢，促使染色体组突变的四倍体细胞分化不定芽，形成植株。经染色计数梢端切片，鉴定出一批同质的四倍体株系，部分植已栽植于果园。此项研究了简易可靠的诱变，有效地避免或减轻了浣诱变中嵌合体的干扰，为人工创造四倍种质，有计划地进行多倍体育种开辟了新途径。 相似文献
16.
不同浸种温度对樟子松种子发芽率的影响 总被引：2，自引：0，他引：2
采用随机区组设计,研究25、35、45、55℃温水浸种24h和不浸种5个处理对樟子松种子发芽率的影响。结果表明:樟子松育苗前,最好用25℃和35℃温水浸种24h,有利提高发芽率。用温水浸种的所有处理14d发芽率均极显著高于不浸种的发芽率,不浸种的发芽率仅为38%。用25、35℃温水浸种均显著高于55℃温水浸种的发芽率;25、35、45℃温水浸种之间、45℃温水浸种与55℃温水浸种之间发芽率不显著。樟子松以25℃浸种24h的发芽率最高,高达52%,35℃浸种24h的发芽率达51%,45℃浸种24h的发芽率达48%,55℃浸种24h的发芽率达46%。 相似文献
17.
茄子茎段组培容易染菌,为了测试15种灭菌方法的灭菌效果,选取紫圆茄、紫长茄、绿茄3种类型茄子品种,根据染菌率和植株再生成活率判断最佳灭菌方法。结果表明,不同类型茄子适用的灭菌方法不同。紫圆茄茎段适宜的灭菌方法为:2%Na Cl O浸泡10min,再用0.1%Hg Cl2浸泡10min;紫长茄茎段适宜的灭菌方法为:4%Na Cl O浸泡10min,再用0.3%Hg Cl2浸泡10min;绿茄茎段适宜的灭菌方法为:6%Na Cl O浸泡10min,再用0.1%Hg Cl2浸泡10min。绿茄茎段保存试验结果表明,低温保存有利于降低茄子茎段组培染菌率,其中最适保存条件为5℃下保存3d以内,染菌率在20%以下,再生成活率保持在60%左右,可以满足植株再生要求。 相似文献
18.
V. J. Gemas M. J. Rijo-Johansen R. Tenreiro P. Fevereiro 《The Journal of Horticultural Science and Biotechnology》2013,88(3):312-319
SummaryCharacterization and selection of olive clones for the production of olive oil is essential in Portugal because of its profitable exploitation. “Moura-Serpa” is the most important Portuguese region for the production of olive oil relying on three cultivars for oil quality. These are ‘Galega Vulgar’, ‘Cordovil de Serpa’ and ‘Verdeal Alentejana’. Therefore, it is of great importance to guarantee the varietal certification of the young trees and the establishment of new orchards. Random Amplified Polymorphic DNA (RAPD) technique was used to characterize these three cultivars. Analysis started using twenty primers that allowed us to distinguish the three cultivars and to select a reduced set of primers. The selected primers were used for inter- and intra-varietal analysis and for establishing a profiling system to assay genetic diversity in other olive cultivars. The method has the potential for use in varietal certification and breeding programmes that need to analyse a high number of samples. 相似文献
19.
Interdisciplinarity,landscape ecology and the `Transformation of Agricultural Landscapes' 总被引：4，自引：0，他引：4
The theme, the `Transformation of Agricultural Landscapes' is used as a context for examining the current status of landscape ecology and its ability to provide a critical set of responses to a defined range of environmental issues. The links between academic structures and the public demand for landscape-based information raises the potential for landscape ecology to provide solutions. Current approaches within landscape ecology are examined and the dominance of the interdisciplinary approach is found to be deficient. A solution is for the land(scape) system itself to become the initial focus of landscape research. A land system has its own systematic properties which extend beyond the biological dominance of ecosystem science which to many is the basis for landscape ecology. For knowledge of the landscape itself to emerge, landscape ecology must develop more as a discipline with its own theoretical bases and foci than as an interdisciplinary area. 相似文献
20.
Paula J. Peper Claudia P. Alzate John W. McNeil Jalil Hashemi 《Urban Forestry & Urban Greening》2014,13(1):175-183
Tree growth equations are an important and common tool used to effectively assess the yield and determine management practices in forest plantations. Increasingly, they are being developed for urban forests, providing tools to assist urban forest managers with species selection, placement, and estimation of management costs and ecosystem services. This study describes the development of allometric equations for Fraxinus americana and F. pennsylvanica growing in Oakville, Canada. With data collected from 103 ash trees, five allometric models were tested to develop equations estimating diameter-at-breast-height (dbh), tree height, crown width and crown height, using age and dbh as explanatory variables. Mean annual growth rates are presented to demonstrate species growth performance and were not significantly different over the first 40 years of growth for the two species. Of all the tested random coefficient models for both species, the cubic with weight 1/x provided the best fit for estimating dbh from age. The best models for other parameters were the loglog for crown height from dbh, the quadratic for crown diameter from dbh, and the linear for tree height from dbh for F. americana. Model types showed more consistency for F. pennsylvanica with linear providing the best fit for crown diameter, crown height and tree height from dbh. The number of model types suggests the difficulty of fitting any single model to the vast array of conditions affecting plant growth in urban areas where management practices and environment can significantly influence tree size and growth. These models may be used to estimate the growth of ash tree populations in Oakville and communities with similar climate, soil, planting, and management environments. 相似文献