西藏城乡居民点空间分异特征与影响因素

西藏地处青藏高原腹地,区内适宜人类生活的空间十分有限,居民点空间分布受多因素制约.为揭示西藏居民点的空间分布特征和主要影响因素,采用高分影像,基于目视与机器解译结合提取西藏城乡居民点斑块数据,运用核密度、空间热点探测、GeoDetector等方法探索其空间分异特征与影响因素,以期为今后高原地区宜居地选址、制定区域经济发展等相关政策提供参考.结果表明: 西藏城乡居民点呈聚集分布模式,整体密度分布差异较大;呈以拉萨市为高密度核心,昌都市、林芝市、阿里地区为低密度边缘的“核心-边缘”结构;高密度核心区拉萨市斑块密度多达220 ind·km^-2,而低密度边缘区密度最大仅为5.7 ind·km^-2,两个区域相差43倍.西藏城乡居民点规模高低值聚簇现象显著,大斑块高值数量稀少,小斑块低值数量绝对优势突出;大斑块高值占比仅为3.7%,集中分布于拉萨市和山南市,低值聚簇区占比达到67.2%,主要分布于羌塘高原的阿里地区和那曲市.西藏城乡居民点被划分成6种类型,形成了以“一江两河”地区和“三江流域”为中心的两个圈层结构,由内到外依次为大斑块主导型、中密度团簇型、高密度散点型、低密度散点型和高寒地无人型;拉萨市以中密度团簇型为主,占比为31%,山南市以低密度散点型为主,占比为38%,昌都市以低密度散点型为主,占比高达51%,阿里地区、那曲市和日喀则市均以高寒地无人型为主,其中,在阿里地区占比高达64%.不同影响因子对西藏城乡居民点空间分布的影响程度差异性显著;人口和GDP对城乡居民点的分布均具有很强的决定性;此外,城镇居民点表现出强烈的道路指向性,农村居民点更多地表现为河流指向性.     

城乡二元差异视角下横断山区县域尺度居民生计水平测度

城市化导致城乡居民生计差异凸显,区域尺度的居民生计研究需充分考虑该差异。采用可持续生计方法(SLA),基于县域尺度建立城乡差异化的居民生计测度体系,引入城乡差异因子测度了横断山区县域的居民生计水平。结果表明：(1)引入城乡差异因子能一定程度消除居民生计水平测度研究中城镇居民生计优势对区域整体生计水平的放大作用;(2)2000—2015年横断山区城乡二元性结构特征显著,期间城乡居民生计关键驱动因子差异明显,乡村居民生计发展逐步由自然资本驱动转变为物质资本驱动,城镇规模超过产业发展状况成为影响城镇居民生计发展的关键影响因子,城乡统筹来看,投资规模和信息获取能力开始愈发的显现其对于居民生计发展的积极作用;(3)横断山区县域居民生计水平总体偏低,发展动能总体不足,两极化发展趋势日益明显;(4)区域居民生计水平总体呈南高北低的空间分布格局,同海拔、坡度呈显著的负相关关系,区域内越是生计脆弱的县域,其居民生计发展越易受到自然环境的制约,同时县域居民生计水平同区域劳动力数量、经济规模显著正相关,劳动力充足、经济发展水平较高的县域其居民生计对自然环境扰动具有更强的韧性。总体来看引入城乡差异因子的可持续...     

The assessment of the impact of different radon sources into indoor air

The contributions of different radon sources into total indoor radon level can differ in some times depending on geographical and climatic features of the locality, building characteristics, lifestyle and habits of the population. The revealing of most significant radon sources for examined locality and the assessment of their relative contributions will allow planning expected radon levels during building design stage. The analysis of the factors influencing indoor radon levels and the computation of radon enter to dwellings from different sources were carried out in Tomsk. About 200 dwellings were investigated on the radon presence by solid state track detectors. The results of the comparative analysis of the theoretical and experimental sets are discussed in this paper.     

Prevalence of Helicobacter pylori Infection and Identification of Risk Factors in Rural and Urban Beijing, China

Background:  The prevalence of Helicobacter pylori is higher in developing countries such as China. The aim of this study was to investigate the prevalence of H. pylori in one rural and one urban region of Beijing, China.
Materials and Methods:  Healthy individuals in rural Pinggu and urban Haidian voluntarily participated in this study. The diagnosis of H. pylori infection was reached using the ¹³C-urea breath test. Associations between H. pylori and sex, age, living area (i.e. rural vs urban), education level, smoking, and alcohol consumption were evaluated.
Results:  Of the 1232 included subjects, 54.7% of tested individuals residing in Pinggu and 41.3% in Haidian were positive for H. pylori . In urban region, more individuals were negative for H. pylori (429 of 731), whereas in the rural region, more individuals were positive for H. pylori ( p <  .05). Univariate analysis identified geographic area and lower education and annual income as significant factors associated with H. pylori . Men in rural areas were more likely than women in rural areas to be infected, and both men and women in the rural area were more likely to be positive for H. pylori than men and women in the urban area (all p  < .05).
Conclusions:  H. pylori infection is common in both rural and urban regions of Beijing. Residing in a rural area, having a lower family income, and lower education level are significant risk factors associated with infection.     

铁西区城市改造过程中建筑景观的演变规律

探索城市改造过程中景观的变化规律对城市景观变化的预测有重要的指导意义。以沈阳市铁西区1997、2002、2005、2008年建筑物三维信息为基础数据。按照建筑物使用性质将其分为居住、工业、商业、教育与医疗、其他建筑5类,按照建筑物的高度将其分为平房、低层、多层、中高层、高层和超高层6类。采用转移矩阵法分析了不同时段建筑类型的更替规律。并将探索性空间数据分析法应用于建筑改造空间分布特征的研究。结果显示:1997到2002年,居住建筑是建筑改造的主体。2002年后,工业建筑成为建筑改造的主体。1997到2008年,不同高度类型的建筑更替顺序为:平房→低层建筑→多层建筑。新增建筑先以低层为主,后以中高层,逐渐以高层为主。建筑改造在空间上并不是随机分布的,而是存在显著的空间正相关关系。在局部空间范围内,建筑改造呈现成片集中改造的现象。     

城市遮阴环境变化对大叶黄杨光合过程的影响

城市遮阴与自然生态系统遮阴环境不同,它由城市中的建筑、基础设施等人工构筑物所产生,并对植物光合过程产生影响。采用Li-6400便携式光合作用测定系统对北京市不同建筑遮阴环境下的生态因子特征及大叶黄杨光合参数特性进行了现场实验对比观测与分析。研究显示:(1)城市建筑或基础设施布局或格局变化导致建筑遮阴环境光、温等生态因子的差异性变化,主要体现在光合有效辐射(PAR)在时间分布及强度上的显著差异。(2)遮阴改变大叶黄杨的光合参数,日净光合速率曲线为不规则单峰型,由遮阴进入太阳直射时,净光合速率(Pn)明显升高,随遮阴程度加重峰值时间有后延现象,完全遮阴时净光合速率最低。(3)大叶黄杨叶片在有一定时间太阳直射的中度遮阴(2.3h和5.5h)下适应性良好,日均净光合速率、光补偿点(LCP)、光合能力(P_nmax)、叶面积(LA)、比叶重(LMA)没有显著差异,植物主要通过光合色素含量及组成的改变来适应太阳直射时间变短(2.3h)的遮阴环境。(4)遮阴改变植物的光暗适应策略,没有阳光直射的重度遮阴下,大叶黄杨通过其光合、形态、光合色素等多方面的改变来适应遮阴环境,建筑重度遮阴严重影响植物光合过程。探讨了不同程度建筑遮阴对植物光合作用的影响及植物的适应机制,为基于提高其生态服务功能的树种配置和城市规划提供科学依据。     

Lung cancer incidence attributable to residential radon exposure in Finland

This study aimed to estimate (1) the number of avoidable lung cancer cases attributable to residential radon in Finland in 2017, separately by age, sex, dwelling type and smoking status, (2) the impact of residential radon alone and the joint effect of residential radon and smoking on the number of lung cancers and (3) the potential decrease in the number of radon-attributable lung cancers if radon concentrations exceeding specified action levels (100, 200 and 300 Bq m^?3) would have been mitigated to those levels. Population-based surveys of radon concentrations and smoking patterns were used. Observed radon levels were contrasted with 25 Bq m^?3 representing a realistic minimum level of exposure. Lung cancer risk estimates for radon and smoking were derived from literature. Lastly, the uncertainty due to the estimation of exposure and risk was quantified using a computationally derived uncertainty interval. At least 3% and at most 8% of all lung cancers were estimated as being attributable to residential radon. For small cell carcinoma, the proportion of cases attributable to radon was 8–13%. Among smokers, the majority of the radon-related cases were attributable to the joint effect of radon and smoking. Reduction of radon exposure to 100 Bq m^?3 action level would eliminate approximately 30% of radon-attributable cases. Estimates were low compared with the literature, given the (relatively high) radon levels in Finland. This was mainly due to the lower radon levels and higher smoking prevalence in flats than in houses and a more realistic point of comparison, factors which have been ignored in previous studies. The results can guide actions in radon protection and in prevention of lung cancers.

     

Managing conflict between humans and wildlife: trends in licensed operations to resolve problems with badgers Meles meles in England

• 1 Successful wildlife management needs to be underpinned by frequent evaluation of the problems arising and the management techniques used to resolve them. The aims of this review were: (i) to investigate spatial and temporal patterns in the occurrence and characteristics of badger–human conflict in England; and (ii) to determine which factors influence the success of management actions. Licences are required before interfering with badgers or setts, so we carried out analyses of records of applications received by Defra and data from follow‐up monitoring of management actions.
• 2 The number of licence applications rose significantly during the recording period (1994–2004), with an increasing proportion coming from the east of England and from urban, as opposed to rural, areas. Damage problems caused by setts were the most frequent sources of conflict in both urban and rural areas. However, the majority of rural problems related to agricultural land, whereas buildings and gardens were most affected in urban areas. A higher proportion of problems involved outlier setts in urban areas compared with rural areas.
• 3 The use of one‐way gates to exclude badgers from part or all of a problem sett was the commonest management action proposed by Defra Wildlife Advisers, with total sett closure more common in urban, compared with rural, areas. Follow‐up monitoring revealed that the success of action varied in relation to the type of sett causing a problem, the type of management action undertaken and the land use (urban or rural) at the problem location, with total closure of an urban main sett being the least successful strategy. This review provides an assessment of current trends in conflict occurrence and will help in the development of management techniques.

     

Mechanical denaturation of globular protein in the solid state

A method for taking stress-strain diagrams in microsamples prepared from glutaraldehyde-treated monocrystals and amorphous films of hen egg-white lysozyme has been developed. Analysis of the diagrams has shown that the deformation obeys Hooke's law within 0-2%. Upon further deformation of a crystalline sample (up to 6-10%), when a critical stress, sigma(cr), is reached, the protein molecules in the sample denature and become greatly extended. Depending on the crystal type and crystallographic direction, the sample length increases 2-4 times. The critical stress is essentially dependent on the factors affecting intra- and intermolecular interactions: temperature, hydration level and urea concentration. Mechanisms for mechanical denaturation are proposed.     

城市内涝调节服务供需关键区识别与优先级划分

在全球气候变化和城市化背景下,城市内涝灾害频发,严重危及城市居民的人身安全、财产安全及公共安全。如何精准施策,针对关键区域进行城市内涝调节治理已成为社会各界关注并亟需解决的重要问题。基于生态系统服务供需视角,以径流调节率表征城市内涝调节的供给水平,以胁迫性、暴露性和脆弱性指标表征城市内涝调节的需求水平,构建了完整的技术路线和指标体系,从而识别城市内涝调节供需失衡的关键区,并确定规划干预的优先级。基于此,以岛屿型城市厦门岛为例,使用遥感数据和人口、社会、经济数据,运用ArcMap10.8、ENVI5.3和GeoDA平台,模拟评估了城市街区尺度下城市内涝调节服务的供需水平及空间分布特征。通过供需匹配将研究单元划分为:高供-高需,低供-高需,低供-低需和高供-低需4种类型,并识别出114个供需严重失衡的关键区,该类关键区面临城市内涝调节服务供给短缺的严峻挑战,是未来城市规划过程中需要重点优化的对象。在此基础上,使用优先级指数将关键区划分为5个规划干预优先级,明确了城市内涝治理的优先次序。研究结果为开展具有针对性的城市内涝调节治理实践提供了新的科学依据,同时在解决城市内涝灾害问题,推进以人为核...     

Dosimetric assessment of radon in a vegetable system

An alpha-dose calculation due to radon uptake in anthers of Tradescantia, clone 4430, has been performed. Probability distribution density of the dose in the pollen mother cells was calculated by means of a model that simulates the interaction of separate alpha-particles with these cells. It is shown that alpha-radiation from either radon or its decay products surrounding the buds does not reach pollen mother cells because of the short-range alpha-particles. However, it is suggested that radon diffuses through the gap structure of the bud to the anther from which a radon-gas adsorption process takes place. Absorbed-dose calculations in the anther are discussed as well as their relationship to the experimental results of micronucleus induction in pollen mother cells. The radon concentration interval used (0.85 kBq m(-3)-98.16 kBq m(-3)) is equivalent to the exposure to an average environmental radon concentration (40 Bq m(-3)) for 2.3 months or 22.1 years, respectively. The lowest radon concentration to induce micronuclei was 12.1 kBq m(-3), which is 15 times in excess of that adopted for old buildings in Canada.     

Ten-year changes in central obesity and BMI in rural and urban Cameroon

Objective: To compare the 10‐year changes in the distribution of adiposity in rural and urban Cameroonian populations. Methods and Procedures: Two cross‐sectional surveys of populations in the same rural and urban areas of Cameroon, aged ≥24 years, were carried out in 1994 (1,762 subjects) and 2003 (1,398 subjects) using similar methodology. All eligible subjects answered a structured questionnaire on their educational level, alcohol consumption, and tobacco smoking and weight, height, and waist circumference (WC) were measured. Results: Between 1994 and 2003, the age‐standardized prevalence of BMI ≥25 kg/m² increased significantly only in the rural area (+54% for women and +82% for men), while the age‐standardized prevalence of central obesity (WC ≥80 cm (women), ≥94 cm (men)) increased significantly only in the urban population (+32% for women and +190% for men). These differences persisted after adjustments for age group, alcohol consumption, tobacco smoking, and level of education, and within almost all the strata of the studied risk factors. Discussion: Changes in adiposity over time in Cameroon were characterized by an increase of BMI in the rural area and of WC in the urban area.     

Focus: Health Equity: Differences Risk Factors for Hypertension Among Elderly Woman in Rural and Urban Indonesia

Introduction: Hypertension is a major risk factor for cardiovascular disease. A high prevalence of hypertension is found in elderly women. Rural areas have different characteristics from urban areas. Therefore, it is necessary to identify risk factors for hypertension in rural and urban elderly women for optimal therapy management. Methods: This cross-sectional study was conducted in rural (Banyuwangi district) and urban (Surabaya city) areas, East Java, Indonesia. The study was carried out in 2015-2016 in women aged ≥45 years, residing in an area for ≥10 years, and willing to collect urine for 24 hours. Respondents consisted of 54 older adults from rural areas and 51 older adults from urban areas who actively participate in the integrated healthcare center for the elderly. The independent t-test and multivariate logistic regression were used to analyze the data. Results: The prevalence of hypertension in the rural area was 27.8% and in the urban area was 37.25%. The risk factors for hypertension in the urban area were urine sodium level (AOR=1.02, 95% CI=1.001-1.04, p-value=0.043), urine potassium level (AOR=0.88, 95% CI=0.78-0.999, p-value=0.022), and Body Mass Index (AOR=1.26, 95% CI=1.06-1.49, p-value=0.008). Meanwhile, the factor associated with hypertension in the rural area was age (AOR=1.08, 95% CI=1.003-1.16, p-value=0.042). Conclusion: The prevalence of hypertension in the urban area was higher than in the rural area. There were differences in risk factors for hypertension that occurred both in rural and urban areas. However, risk factors in both areas are equally important to overcome. Collaboration from multiple stakeholders and sectors is urgently needed, such as the Public Health Center, Integrated Assistance Post for Non-Communicable Diseases, and the local health office.     

中国人身体质量指数的地理性分布

2009-2013年测量了中国11个汉语方言族群26954例汉族人的身高、体重值,计算了身体质量指数(I_(bm)),将汉族人的I_(bm)与经度、纬度进行相关分析。研究结果表明:总的说来,随年龄增长,11个方言族群I_(bm)值均呈线性增大,并且年龄组间差异均具有统计学意义。11个族群中,北方话族群I_(bm)值明显大于南方各族群。乡村男性(r=0.671; p0.05)、城市女性(r=0.043; p=0.820>0.05)I_(bm)与经度无相关。按照I_(bm)均数大于24.0、I_(bm)均数在23.1～24.0之间、I_(bm)均数小于23.0,可以将中国方言族群分成3个层次,中国北方话族群均分布在第1、2层次,南方族群主要分布在第2、3层次,也就是说11个族群大致按照纬度高低顺序依次分布在第1、2、3层次。遗传、环境、饮食、劳作强度等因素都不同程度影响身高、体重,也影响中国人的I_(bm)值。     

Identifying the contradiction between the cultivated land fragmentation and the construction land expansion from the perspective of urban-rural differences

Land use contradictions and conflicts between arable and construction land areas have long been major topics in the field of land use research. However, few studies have explored the impact of differences in development between urban and rural areas on the amount and landscape level of arable land. In this study, two decades of data were combined to classify the Yangtze River Delta mega-city cluster area, where urbanization has been evident in China, into urban and rural areas. Based on this, we analyzed the differences in the changes in the amount of arable land caused by the expansion of urban and rural construction land. In this study, a comprehensive framework of arable land fragmentation indicators was constructed and the geographically weighted regression model was introduced to detect spatial and temporal dynamic change patterns of arable land fragmentation caused by different urbanization processes in urban and rural areas. The results show the following: (a) The expansion of urban and rural construction land caused arable land loss, and both contributed non-negligibly to arable land loss. (b) The distribution of the arable land fragmentation index showed obvious spatial heterogeneity, and its low-value area corresponded to a lower level of urban/rural construction land development. However, its high-value area did not show a stable dependence on the level of urban/rural construction land development. (c) Changes in urban and rural built-up land were the driving factors for changes in the degree of arable land fragmentation. In general, the expansion of the urban fringe increased the fragmentation of arable land, and the intensive expansion of urban centers curbed the fragmentation of arable land. However, rural construction land exhibited a stronger and more widespread impact than urban areas as a whole. This study contributes new ideas for arable land conservation policies under the growing mechanization of agriculture, especially in areas with large differences in development between urban and rural areas. Additionally, it emphasizes the need for rational planning of construction land in rural areas. The results of this study can provide references for urban-rural development planning, rural revitalization, and implementation of arable land protection.     

东南诸河流域1990-2015年土地利用时空变化特征及驱动机制

土地利用/覆被变化作为影响全球环境变化的重要因素,是人类活动最直接的反映,其驱动力分析能够很好地揭示人类活动对土地资源的影响机制。运用ArcGIS空间分析和SPSS主成分分析等方法,从整个东南诸河流域片区的尺度上,研究了包含中国台湾地区在内的1990—2015年间的土地利用时空变化特征,并探究其主要驱动机制。研究结果为:(1)全流域各土地类型面积占比为:林地耕地草地城乡建设用地水域未利用土地,林地与耕地的空间分布特征均为"北聚南散,北多南少",城乡建设用地集中分布在经济较为发达的台湾海峡两岸沿海地区以及流域大陆北部靠近长江三角洲的地区。(2)全流域土地类型的面积变化量为:城乡建设用地耕地草地林地水域未利用土地。流域土地利用综合动态度为0.68%,整体用地类型转化程度先降低再增加,并以城乡建设用地和耕地为主要变化类型。流域南部各市的土地利用变化较北部剧烈,台湾地区主要土地利用变化类型为耕地和城乡建设用地。(3)大陆地区城乡建设用地变化的主要驱动力为人口数量及结构、城市化和社会经济发展,台湾地区在此基础上增加了社会工农产业结构调整因素。大陆耕地变化的主要驱动力为人口数量及结构、城市化水平和社会工农产业结构,社会工农产业结构和农业生产水平是台湾地区耕地变化的主要驱动力。本研究为东南诸河流域土地资源规划管理提供科学依据,为自然流域尺度的土地利用变化及其驱动机制研究提供可靠实例。     

Body Mass Index and Cardiovascular Disease Risk Factors in Seven Asian and Five Latin American Centers: Data from the International Clinical Epidemiology Network (INCLEN)

We have tested the hypothesis that the relationship between body mass index (BMI) and other cardiovascular disease (CVD) risk factors as well as socioeconomic status is different in five Latin American populations (where BMI is high) and seven Asian populations (where BMI is low). Random samples of approximately 200 males aged between 35 and 65 years were selected from 12 general or industrial populations in Latin America and Asia. Standardized measures of height, weight, blood pressure, blood cholesterol, cigarette smoking, highest level of completed education, occupation and income were made. The mean BMI (kg/m₂) was 253 (SD 3.74) in the five Latin American populations (which were all urban), 22.2 (SD 3.24) in the four Asian urban populations and 21.4 (SD 3.33) in the three Asian rural populations. Despite the differences in mean BMI levels, statistically significant positive relationships of a similar magnitude were seen between BMI and blood pressure levels in Latin America and Asia. Similarly, there was a statistically significant positive relationship found between BMI and total cholesterol in both Latin American and Asian urban samples, but of a higher magnitude in Asian rural samples. Current cigarette smokers had significantly lower BMI than ex-smokers or never smokers in Latin America and Asia. In Asia, there were statistically significant positive associations between BMI and levels of education and income as well as with occupation — these relationships were stronger for education and occupation in rural than in urban samples. There were no statistically significant associations between BMI and these measures of socioeconomic status in Latin America. The similarities of the associations between BMI and blood pressure and cholesterol levels in the two groups suggest that efforts to reduce BMI in all populations is likely to be important in reducing risk of CVD. Preventing the future rise of BMI in populations tions where BMI is still relatively low is a high priority. The difference in association between BMI and socioeconomic status in the different population groups requires study of the way sociocultural factors influence behavior that determines BMI levels.     

Environmental factors, health-related habits, and serum selenium levels in cancer patients and healthy controls

Previous studies conducted in Yugoslavia indicated that the concentration of selenium in soil, food items, and serum of the population is very low. The aim of the study was to investigate the possible relationship among environmental, health-related habits, nutrition, and selenium serum levels in cancer patients and the healthy population. The case-control study included a group of cancer patients and a matched group of healthy controls: 57 cancer patients and 41 healthy controls living in Stari Grad (an urban area of Belgrade), as well as 17 cancer patients and 13 healthy controls living in Barajevo (a rural community in the vicinity of Belgrade). The healthy controls were matched to cancer patients in sex and age; they were not blood related. The selenium serum levels were measured by atomic absorption spectrophotometry. Health-related habits and relevant dietary factors (“food frequency” method) that may influence the selenium serum levels were assessed by questionnaires. The differences in average values of selenium serum levels between the cancer patients and healthy controls were not significantly different, but both were below the lowest recorded in referential studies. A significant difference between the values obtained from urban and rural subgroups was noted. The most important factors that influenced the level of selenium included the residence place in the region with selenium deficiency (Barajevo), age, associated chronic diseases, and some dietary factors potentially related to the intake of selenium. The results obtained in this investigation pointed out that use of selenium supplementation in this area should be seriously considered. Deceased     

Geographical Factors Affecting Bed Net Ownership,a Tool for the Elimination of Anopheles-Transmitted Lymphatic Filariasis in Hard-to-Reach Communities

Vector control, including the use of bed nets, is recommended as a possible strategy for eliminating lymphatic filariasis (LF) in post-conflict countries such as the Democratic Republic of Congo (DRC). This study examined the geographical factors that influence bed net ownership in DRC in order to identify hard-to-reach communities that need to be better targeted. In particular, urban/rural differences and the influence of population density, proximity to cities and health facilities, plus access to major transport networks were investigated. Demographic and Health Survey geo-referenced cluster level data were used to map bed net coverage (proportion of households with at least one of any type of bed net or at least one insecticide-treated net (ITN)), and ITN density (ITNs per person) for 260 clusters. Bivariate and multiple logistic or Poisson regression analyses were used to determine significant relationships. Overall, bed net (30%) and ITN (9%) coverage were very low with significant differences found between urban and rural clusters. In rural clusters, ITN coverage/density was positively correlated with population density (r = 0.25, 0.27 respectively, p<0.01), and negatively with the distance to the two largest cities, Kinshasa or Lubumbashi (r = −0.28, −0.30 respectively, p<0.0001). Further, ownership was significantly negatively correlated with distance to primary national roads and railways (all three measures), distance to main rivers (any bed net only) and distance to the nearest health facility (ITNs only). Logistic and Poisson regression models fitted to the rural cluster data indicated that, after controlling for measured covariates, ownership levels in the Bas-Congo province close to Kinshasa were much larger than that of other provinces. This was most noticeable when considering ITN coverage (odds ratio: 5.3, 95% CI: 3.67–7.70). This analysis provides key insights into the barriers of bed net ownership, which will help inform both LF and malaria bed net distribution campaigns as part of an integrated vector management strategy.     

长三角地区城市生态旅游发展水平时空演变及其影响因素

城市生态旅游作为旅游可持续发展的一种理想模式,是对城市环境问题和旅游发展方式的一种回应。基于城市生态旅游核心要义,构建城市生态旅游发展水平评价指标体系,运用熵权TOPSIS法对2010-2019年长三角地区41个城市的城市生态旅游发展水平进行测度,通过标准差椭圆和马尔科夫链分析其时空演变特征,并利用地理探测器探析城市生态旅游发展的影响因素。结果表明:(1)长三角地区城市生态旅游各维度发展水平增速各异,供给和保障是影响综合发展水平的主要因素,各维度空间格局差异显著;(2)城市生态旅游综合发展水平呈波动上升态势,增速较缓;空间分布较不均衡,已初步形成"东南高-西北低"的分布格局;(3)城市生态旅游发展水平重心呈现"西北-东南-西北"的偏移规律,向东南部集聚程度逐渐增强,水平等级转移仅发生在相邻等级之间;(4)交通发展水平和城镇化水平对城市生态旅游发展的影响较为显著,经济发展水平和居民收入水平的影响逐渐增强,产业结构水平和环保重视程度的促进效果不显著;两因子的交互作用大于单因子的作用力,表现出双因子增强或非线性增强的交互关系。研究结果可为长三角地区提高城市生态旅游发展水平与全面推进旅游可持续发展提供一定的理论依据与科学参考。