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191.
Lawns are considered monocultures and lesser contributors to sustainability than diverse nature but are still a dominating green area feature and an important cultural phenomenon in cities. Lawns have esthetical values, provide playground, are potential habitat for species, contribute to carbon sequestration and water infiltration, but also increase pesticides, fertilization, are monocultures and costly to manage at the same time. To evaluate the potential impact of lawns, whether positive or negative, it is of interest to estimate the total lawn cover in cities and its change over time. This is not a straightforward process, e.g., because many lawns are small and covered by trees. In this study we review the existing literature of lawn cover in cities and the different methodologies used for cover estimation. We found both pros and cons with NDVI and LiDAR data as well as manually interpreted aerial photos. The total cover of lawns in three case study cities was estimated to 22.5%. By extrapolating these percentages to all Swedish cities lawn cover was estimated to 2589 km2 (0.6% of the terrestrial surface). The approximated total municipal management cost of lawns in all Swedish cities was 910,000,000 USD/ year. During 50 years lawn area almost doubled in relative cover and 56% of them were continuously managed. Since lawns constitute large parts of the urban greenery and are costly to manage it is highly relevant to consider their social, ecological and cultural value compared to alternatives, e.g., meadows with less intensive management. 相似文献
192.
Skew normal distribution is an alternative distribution to the normal distribution to accommodate asymmetry. Since then extensive studies have been done on applying Azzalini’s skewness mechanism to other well-known distributions, such as skew-t distribution, which is more flexible and can better accommodate long tailed data than the skew normal one. The Kumaraswamy generalized distribution (Kw ? F) is another new class of distribution which is capable of fitting skewed data that can not be fitted well by existing distributions. Such a distribution has been widely studied and various versions of generalization of this distribution family have been introduced. In this article, we introduce a new generalization of the skew-t distribution based on the Kumaraswamy generalized distribution. The new class of distribution, which we call the Kumaraswamy skew-t (KwST) has the ability of fitting skewed, long, and heavy-tailed data and is more flexible than the skew-t distribution as it contains the skew-t distribution as a special case. Related properties of this distribution family such as mathematical properties, moments, and order statistics are discussed. The proposed distribution is applied to a real dataset to illustrate the estimation procedure. 相似文献
193.
The current study examined associations between mothers’ behavioral profiles during mother‐child conflict interactions and their children's social skills. This person‐centered approach classified 181 mothers according to their levels of emotional responsiveness, intrusiveness, negativity, and engagement facilitation behaviors during an eight‐minute conflict discussion task with their child. Three distinct classes of mothers were identified using latent profile analysis: sensitive/engaged, moderately sensitive/engaged, and insensitive/disengaged. An analysis of covariance indicated that children of mothers in the sensitive/engaged group had significantly higher social skills than children of mothers in the moderately sensitive/engaged and insensitive/disengaged groups. Results suggest that mother‐child conflict interactions may benefit children's social development when mothers facilitate their children's participation in a highly sensitive manner. 相似文献
194.
Elena D. Concepción Martin K. Obrist Marco Moretti Florian Altermatt Bruno Baur Michael P. Nobis 《Urban Ecosystems》2016,19(1):225-242
Urban growth is a major factor of global environmental change and has important impacts on biodiversity, such as changes in species composition and biotic homogenization. Most previous studies have focused on effects of urban area as a general measure of urbanization, and on few or single taxa. Here, we analyzed the impacts of the different components of urban sprawl (i.e., scattered and widespread urban growth) on species richness of a variety of taxonomic groups covering mosses, vascular plants, gastropods, butterflies, and birds at the habitat and landscape scales. Besides urban area, we considered the average age, imperviousness, and dispersion degree of urban area, along with human population density, to disentangle the effects of the different components of urban sprawl on biodiversity. The study was carried out in the Swiss Plateau that has undergone substantial urban sprawl in recent decades.Vascular plants and birds showed the strongest responses to urban sprawl, especially at the landscape scale, with non-native and ruderal plants proliferating and common generalist birds increasing at the expense of specialist birds as urban sprawl grew. Overall, urban area had the greatest contribution on such impacts, but additional effects of urban dispersion (i.e., increase of non-native plants) and human population density (i.e., increases of ruderal plants and common generalist birds) were found. Our findings support the hypothesis that negative impacts of urban sprawl on biodiversity can be reduced by compacting urban growth while still avoiding the formation of very densely populated areas. 相似文献
195.
Kerri Kruse Joanna White Darren K. Walton Danny Tu 《International Gambling Studies》2016,16(2):328-346
Evidence suggests that problem gambling is an unstable state where gamblers move into and out of risk over time. This article looks at longitudinal changes in risky gambling and the factors associated with an increased risk (measured by the Problem Gambling Severity Index [PGSI]) in the current New Zealand context, which has experienced a doubling of the electronic gaming machine (EGM) market over the last two decades. Respondents from a nationally representative baseline sample (n = 2672) were recontacted two years later to assess changes in gambling behaviours. Among the 901 respondents reached at follow-up, average gambling risk increased over time, and the prevalence of those who had at least some level of gambling risk (i.e. low-risk or greater) more than doubled (from 4.7% to 12.4%). The majority (80.2%) of those who were at risk at follow-up had not been at risk at baseline. Multivariate linear regression analyses show that the predictors of low to moderate increased risk include Pacific ethnicity; high neighbourhood deprivation status; baseline frequent, continuous gambler type; baseline PGSI status; and playing EGMs. These findings highlight the need to develop theories of gambling addiction trajectories and to identify the earliest point along the trajectory where public health interventions should occur. 相似文献
196.
The purpose of this study is to explore the conflict between use and preservation in national parks policy as seen through
the mission statement of the National Parks Service. The histories of the national parks were qualitatively coded in order
to further explore this controversy, or what we have termed “mission rivalry”. 相似文献
197.
Peter K. Dunn Michael D. Carey Michael B. Farrar Alice M. Richardson Christine McDonald 《The American statistician》2017,71(4):326-335
The six recommendations made by the Guidelines for Assessment and Instruction in Statistics Education (GAISE) committee were first communicated in 2005 and more formally in 2010. In this article, 25 introductory statistics textbooks are examined to assess how well these textbooks have incorporated the three GAISE recommendations most relevant to implementation in textbooks (statistical literacy and thinking; use of real data; stress concepts over procedures). The implementation of another recommendation (using technology) is described but not assessed. In general, most textbooks appear to be adopting the GAISE recommendations reasonably well in both exposition and exercises. The textbooks are particularly adept at using real data, using real data well, and promoting statistical literacy. Textbooks are less adept—but still rated reasonably well, in general—at explaining concepts over procedures and promoting statistical thinking. In contrast, few textbooks have easy-usable glossaries of statistical terms to assist with understanding of statistical language and literacy development. Supplementary materials for this article are available online. 相似文献
198.
Using a convenience sample of 318 undergraduate and graduate social work students (193 women and 125 men) from a public university in India, this study examined the differences between Indian social work students' perceptions toward the role of government in addressing social issues in India. Using Predictive Analytics Software (PASW) 18, several statistical procedures were conducted to analyze the relationship between social work students' demographic variables and their perceptions of the government's role in addressing social issues in India. The results indicated that older social work students were more likely to perceive that the government should ensure equal opportunities for citizens. Female social work students were more likely to perceive that the government should ensure housing for citizens. BSW students were more likely to perceive that the government should ensure employment of citizens. Macro social work students were more likely to perceive that the government should ensure equal opportunities, housing, food, employment, and health insurance for citizens. The findings of this study may help social work educational administrators and faculty in India to develop a curriculum that provides social work students with the opportunity to critically examine the complex relationship between age, gender, marital status, number of children, socioeconomic status, educational status, area of concentration, and the role of the government in addressing social issues. Doing so will prepare social work students and professionals to think and engage in a manner that will allow them to challenge and advocate for a change to the status quo. 相似文献
199.
The present study investigated whether perception of receiving emotional support mediates the relationship between one partner's giving of emotional support and the other partner's depressive symptomatology using a population-based sample of 423 couples from the Changing Lives of Older Couples study. A path model was used guided by the Actor-Partner Interdependence Model. Results indicated that spouses' giving emotional support was related to the degree to which their spouse reported receiving emotional support. Perception of receiving emotional support, in turn, was related to lower depressive symptomatology of the support recipient. Both husbands and wives can benefit from emotional support through their perception of receiving emotional support, and spouses' perceptions, as well as their actions, should be considered in support transactions. 相似文献
200.
This study highlights the changes that have occurred at postsecondary institutions after conversion from not-for-profit to for-profit control. Using Delta Cost Project Data and a pre-post study design with a control group of not-for-profit institutions that did not convert, comparisons are drawn. The findings suggest that institutions that convert experience greater enrollment growth, a decline in fulltime employment levels per full time equivalent (FTE) student, no change in average expenses per FTE student, a decrease in total revenue, a decrease in Pell Grants received, a decrease in tuition and fees revenue, and a decline in average subsidy per student post conversion. These findings are critical to the creation of informed policy decisions regarding institutional conversions. 相似文献