The influence of urban park characteristics on ant (Hymenoptera, Formicidae) communities

As rapid urbanization continues, existing natural areas within urban zones will play a critical role in safeguarding remaining biodiversity. Ants are an integral part of almost every terrestrial ecosystem, including urban environments, and understanding which environmental characteristics influence their persistence is critical. In this study, 24 protected natural areas within urban parks including mosaic, scrub, herbaceous and forest habitats were surveyed for ants with 563 pitfall traps. The data provide insights into the distribution and abundance of ant fauna in San Francisco natural areas, as well as which characteristics of parks have the most influence on ant community composition. A total of 2,068 ant individuals representing 15 species were collected. A regression analysis revealed that urban forests reduced ant richness and abundance and that there was little or no impact of the Argentine ant on native ants. Natural area size and shape were not important in explaining variations in overall ant species richness and abundance, with many smaller natural areas harboring ant populations that are just as diverse and robust as larger areas.     

Determining the effect of urbanization on generalist butterfly species diversity in butterfly gardens

This study investigates the effects of urbanization on local butterfly populations and the role of butterfly gardens in preserving regional butterfly diversity. Data are from 135 butterfly gardens of varying size, location, and number of blooming plants in the Washington DC metropolitan area observed during 2001 and 2002. We investigated the species diversity for comparable gardens in rural, suburban, and urban locations to determine whether the landscape matrix surrounding otherwise suitable habitat affects the diversity found in the habitat. We hypothesized that, once factors such as garden size and number of blooming plant species were taken into account, butterfly diversity for 12 generalist species would decrease as urbanization increased. We found that there were systematic decreases (with one exception) in diversity from rural to suburban to urban gardens only for medium-sized gardens (0.10 to 0.20 ha) with one to ten types of blooming plants, and large gardens (>0.20 ha) with over 20 types of blooming plants. Gardens of other sizes or plant communities showed some decreases in diversity from rural to suburban to urban sites, but these differences were not consistent across the urban/rural gradient. Results of this study indicate that local butterfly diversity is negatively affected by increasing levels of human population, but that the matrix is just one factor determining generalist species diversity.     

Effects of urbanization and land use on fish communities in Valley Creek watershed, Chester County, Pennsylvania

Valley Creek watershed, located in southeastern Pennsylvania, is a small, fourth-order stream that empties into the Schuylkill River at Valley Forge National Historic Park, thirty-five kilometers northwest of Philadelphia. The 64 km² watershed has been under extreme urbanization pressure over the past 30 years, resulting in rapidly increasing impervious surface cover and decreasing open space. The purpose of this study was to document some of the effects of urbanization on fish assemblages by quantifying the fish communities at fifteen sites throughout the watershed. Long-term effects of continued urbanization were identified, as data from the present study were compared to similar work completed nearly ten years earlier. There has been a shift in species composition from intolerant, coldwater species to more tolerant, eurythermal species. Currently, Valley Creek is supporting a naturally reproducing population of brown trout, but there has been a marked decline in relative abundance and range since 1993. Increased stream temperature from urban run-off is one of the primary issues in Valley Creek. Species composition was unique at each of the 15 stations owing to the effect of local land use in each station’;s drainage area. Fish assemblages revealed a patchy, non-continuous pattern of fish distribution.     

Effects of urbanization on trust: Evidence from an experiment in the field

I conducted a trust game in the field within a natural experiment paradigm to test the effects of urbanization on both in- and out-group trust. I found that urbanization has a larger positive effect on out-group trust than on in-group trust. My findings provide new knowledge to the literature on the intricacy of the urbanization-trust relationship and contribute to the ongoing discourse on the different foundations underpinning in-group and out-group trust.     

上海城市人口总量控制与结构优化研究

上海的人口总量和结构一直与其独特的工业化、城镇化进程密不可分。工业化带动人口发展,人口发展推动城市发展。改革开放以来,上海正处于第四波工业化时期,人口增长较快。在人口结构上,户籍人口老龄化,而外来人口具有就近流动、城城流动、定居化特点,且教育水平逐年提高。从承载力上看,上海人口总量合理,但人口分布的不合理影响了人口结构的发展、城市社会的融合,带来了核心区人口过密、产城融合不畅的问题,以及偏好"人脑"、排斥"人手"的问题。面对人口老龄化和可能的人口逆流,上海应稳定人口总量,建设整体推进的多中心发展人口分布格局,完善户籍制度改革,破解"新二元结构",推动社会保障和公共服务均等化,同时结合政府改革,完善相关配套改革措施。     

The effects of urbanization on ant communities and myrmecochory in Manitoba,Canada

With the increase in urbanization globally, there is an increased need to understand the ecology of forest fragments in urban and urbanizing landscapes. Although urban forests are known to be relatively lacking in plants whose seeds are dispersed by ants, little is known about the effects of urbanization on the community composition and behaviour of forest dwelling ants. Ant communities in forest fragments along an urban–rural gradient were described using a rapid quadrat search technique and multivariate analysis. Interactions between the ants and seeds of the myrmecochorous Viola pubescens within a subset of these forests were described using a series of cafeteria experiments. Urbanization was found to be associated with changes in microhabitat characteristics and a concomitant simplification of the ant community. Despite this, the removal rate of V. pubescens seeds actually increased in urban forests, which may be a result of the foraging behaviour of the remaining species.

The structure of a micro-bat community in relation to gradients of environmental variation in a tropical urban area

We investigated patterns of community structure (species composition, foraging activity, and nightly foraging patterns) of bats in relation to gradients of environmental variation in a tropical urban area. A total of 32 sites spread equally across eight habitat types were sampled in the city of Townsville, North Queensland, Australia. Each site was sampled on 3 non-consecutive occasions using automated AnaBat systems. Eleven species were confidently identified while a possible four more were identified only to the genus level. Ordination of environmental variables measured at these sites identified two distinct environmental gradients reflecting the degree of urbanisation and foliage density. With increasing urbanisation there was a decline in species richness and total foraging activity. We used regression trees to characterise foraging preferences of each species. This analysis suggested that only one species of Mormopterus was able to exploit the resources provided by urbanisation. This species foraged in areas with higher numbers of white streetlights. The remaining species of bats preferred to forage within close proximity to natural vegetation and with low numbers of streetlights. The density of vegetation in long-established suburbs did not substantially reverse the trend for urban areas to have fewer bat species than original habitats.     

The effect of urbanization gradients and forest types on microclimatic regulation by trees,in association with climate,tree sizes and species compositions in Harbin city,northeastern China

Urban Ecosystems - Rapid urbanization and climate change require stronger microclimatic regulation by urban trees, and maximizing their cooling, humidifying, and shading functions requires an exact...     

对我国城市化健康发展的理论思考——城乡统筹发展的视角

本文简要回顾了我国近10年来城市化快速发展的理论和政策背景,指出快速城市化进程中存在土地、能源等自然资源过渡消耗和浪费问题,也存在重城轻乡等突出社会问题;采用人口供需平衡的方法,分析评价了我国人口城市化水平同经济发展水平、工业化水平和土地城市化的关系;对城市化加速理论进行剖析,认为我国当前工业化技术体系不适用于机器技术体系下城市化加速的经验规律,应该结合我国新型工业化的要求走资源节约型的新型城市化道路;建议适当降低城市化发展目标与速度,纠正城市化过程中＂城市偏向＂和＂以物为本＂的做法,体现国家赋予城市化带动农村发展的重任,实现城乡统筹发展。     

The dynamics of planted and colonising species on a green roof over six growing seasons 2001–2006: influence of substrate depth

Fifteen herbaceous perennial grass and herb species were planted into experimental green roofs in spring 2001. The species differed widely in their origins, heights, flowering times, life spans and growth forms but all were typical of dry and nutrient-stressed habitats. Three individuals of each species of a standardised size were randomly assigned to a planting grid at 20 cm apart in each experimental replicate plot at substrate depth of either 100 or 200 mm. Each treatment was replicated three times. During each growing season, the mean height and spread of each individual was recorded, together with flowering performance and % vegetation cover. In addition the numbers and % covers of all spontaneous colonised species were recorded. Greatest survival, diversity, size and flowering performance of planted species occurred at 200 mm depth. Bare ground and moss cover was greatest at 100 mm, as was diversity of colonising species. Differences between the early years and the final years of the experiment indicate the need for long-term monitoring of green roofs in addition to short-term experiments.     

The influence of organizational social responsibility on involvement behavior in community sport membership associations

Membership‐based associations are critical to their local communities and the overall social impact of the nonprofit sector. This study examines how organizational social responsibility within nonprofit membership associations influences positive member involvement behaviors, including volunteering, speaking positively about the club, and member loyalty. Self‐administered online questionnaires were completed by 735 members within seven grassroots membership associations in Ontario, Canada offering community‐based sport programs. Results show that members are somewhat aware of and felt positively about their organization's socially responsible efforts. Awareness of these efforts had a positive direct effect on the involvement behaviors of members, including intention to stay involved with their club and speaking positively about their club to others (i.e., word of mouth). Members' level of social consciousness was found to have a positive direct effect on word of mouth. Furthermore, members' positive evaluation of sport clubs' socially responsible initiatives was found to partially mediate the positive relationship between social consciousness and involvement behavior, as well as partially mediate the positive relationship between awareness of those efforts and involvement behavior. Results of this research provide grassroots membership associations with an in‐depth understanding of how their organization's efforts toward social responsibility influence member perceptions and behaviors, which may help them focus their efforts and more effectively manage their social change agenda moving forward.     

The impact of biological preferences on parental investments in children and step-children

A remarriage typically involves significant changes in a family’s financial circumstance, and these changes, combined with the relative bargaining relationship between spouses, likely affect the well-being of the children who are part of the family. In this paper, I use the separate-spheres model, a theoretical model that explains the determinants of bargaining power in marriage, to analyze how a remarried couple’s bargaining relationship affects their child investment in stepfamilies. Based on this theoretical model, I build and estimate an empirical model that investigates the determinants of parental investment. As evidence of parental preference for biological children over stepchildren, I find that an increased wage rate of a biological mother significantly improves her child investment when her husband is a stepfather of the child, while there is no such effect for mothers living with the biological father of the child.

The influence of interviewer characteristics on support for democracy and political engagement in Sub-Saharan Africa*

This study investigates how an interviewer’s characteristics affect how respondents answer survey questions about democracy and political engagement. I analyze data from the 2008 Afrobarometer surveys, in which 810 interviewers surveyed 27,713 respondents across 20 countries in sub-Saharan Africa. Using these data, I study how interviewer education, age, and gender affect two outcomes: (1) response distributions to attitudinal and behavioral survey questions and (2) the likelihood of respondents saying ‘don’t know’ to a survey question. The analysis also investigates how the respondent’s perception of who sponsored the survey (NGO, private sector, government) affects attitudes. The results show that these interviewer characteristics affect the quality of survey data on political attitudes and behaviors. In the discussion, I consider the implications for research based on public opinion data about democracy and political engagement.     

Functional specificity in discussion networks: The influence of general and problem-specific networks on health outcomes

Though commonly used in social science research to measure the influence of social networks, the link between discussing “important matters” within networks and the achievement of instrumental ends is frequently unspecified or untested. To address this gap, we explore the consequences of using the general “important matters” approach versus one in which the substance of discussions is directly linked to the outcomes of interest. The egocentric social networks of people experiencing an acute health crisis are examined. We identify the characteristics of and the degree of membership overlap between “important matters” and “health matters” discussants, and explore their relative power in explaining a wide range of health and health services-related outcomes. We find no evidence for the influence of “important matters” networks, while characteristics of “health matters” networks demonstrate a significant effect across all models.     

The longitudinal effects of influence of parental attachment and emotion regulation on Internet delinquency in early adolescence

ABSTRACT

The purpose of this study was to identify the longitudinal influence of parental attachment and emotion regulation on changes in Internet delinquency. This study used the Korean Youth Panel Survey (KYPS) data, in which 2,844 school-age children were annually assessed from Grade 4 in 2004 to Grade 8 in 2008 in South Korea. Latent growth models were used to examine developmental trajectories of Internet delinquency, parental attachment, and emotion regulation longitudinally. This study showed that adolescents experience an increase in Internet delinquency over the fourth year and a decline in the fifth year. The initial level of parental monitoring had significant effects on the initial level of emotion regulation. In addition, the initial level of parental attachment was associated with a slower rate of acceleration of Internet delinquency across time. The study findings indicate that parental attachment influences Internet delinquency among Korean adolescents. The practice implications of the findings are discussed in terms of Internet delinquency reduction efforts.     

轨道交通建设对苏州商业空间结构的影响研究

文章通过分析苏州商业空间的演变历程和轨道交通建设对苏州商业空间发展可能带来的影响,阐述了未来苏州商业空间结构将经历点状扩散、带形发展、连接成片三个阶段的演变趋势,并提出了苏州建设有序商业空间结构的具体策略,为苏州轨道交通与商业空间建设提供理论依据和决策参考。     

The Influence of Family Structure on Sexual Activity in a Randomized Effectiveness Trial for Minority Youth

This study examined the influence of family structure on the outcomes of a sex education program in Miami, Florida. Using an experimental design, data collection occurred at pretest, 3-month, and 6-month follow-up with a sample of teenagers from high schools with a large majority of minority youth, assigned into treatment (n = 549) and control (n = 424) groups. Results indicated family structure had no influence on predicting teen sexual activity at pretest or at 3- or 6-month follow-up. Additional research using experimental designs is needed to assess the influence of family structure on other areas of adolescent development.     

The Treatment of Relationship Status in Research on Dating and Mate Selection

The relationship status of study participants (e.g., daters, cohabitors, marrieds, or unmarrieds) has implications for understanding dating and mate selection. Procedures used in studies may blur or ignore status distinctions. The authors examined methods used in 791 studies published from 1991 – 2001. Most commonly, status of participants is unspecified, and different statuses are collapsed for analysis. Status of participants is associated with recruitment method, and type (e.g., romantic, friendship) and form (e.g., perceived, current) of relationship measured. Unspecified samples are associated with research on the topics of universal properties or causal conditions, and specified samples with mate selection. The connection between status and topic is becoming more blurred over time. Recommendations for studying and reporting status are provided.     

Disentangling substantiation: The influence of race, income, and risk on the substantiation decision in child welfare

Understanding the source of disparities found at decision-making points along the child welfare pathway is essential to understanding and addressing the overrepresentation of African American children. Although research has documented the existence of disparities, it has been less successful in identifying the explanatory factors behind them. Critiques of research examining these disparities have suggested that poverty is likely a stronger explanatory factor than race, yet analyses that include measures of poverty using data from child welfare systems have largely not been conducted. This study uses data from the Texas child welfare system to identify the factors contributing to disparities at the substantiation decision. Given the relationship between poverty and child maltreatment, the analyses control for the effect of family income, as well as other factors related to maltreatment, to better understand the effect of race on this decision-making point. Findings indicate that when family income is controlled, race is not a significant factor in the substantiation decision. However, when also controlling for caseworker perceptions of risk, race emerges as the stronger explanatory factor. This suggests not only an important relationship between race, income, and risk assessment, but also that disproportionality in the child welfare system is a complex phenomenon that cannot be explained by a single factor. These results further demonstrate that the effect of racial bias on decision-making remains an important consideration in understanding the overrepresentation of African American children.     

The influence of the economic crisis on quality of care for older people: system readiness for innovation in Europe

The aim of this study is to examine the influence of the recent economic crisis on the quality of long-term care for older people in Belgium and the Netherlands. A mixed-method approach was applied, primarily focused on conducting semi-structured qualitative interviews with health professionals working in a management role in organizations providing long-term care for older people. The results show that Dutch organizations seem to be prepared for the influences of the economic crisis on the quality of its care provision primarily in terms of a sound system readiness. At the same time, Belgian organizations seem to be prepared for the influences of the economic crisis on the quality of its care provision primarily in terms of a favorable sociopolitical context. Comparing two countries allows for reciprocal lesson-drawing. The conclusion drawn in this study is that a sustainable long-term care system requires above all stability and structure.