24 research outputs found

    Urban Biodiversity and Landscape Ecology: Patterns, Processes and Planning

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    Effective planning for biodiversity in cities and towns is increasingly important as urban areas and their human populations grow, both to achieve conservation goals and because ecological communities support services on which humans depend. Landscape ecology provides important frameworks for understanding and conserving urban biodiversity both within cities and considering whole cities in their regional context, and has played an important role in the development of a substantial and expanding body of knowledge about urban landscapes and communities. Characteristics of the whole city including size, overall amount of green space, age and regional context are important considerations for understanding and planning for biotic assemblages at the scale of entire cities, but have received relatively little research attention. Studies of biodiversity within cities are more abundant and show that longstanding principles regarding how patch size, configuration and composition influence biodiversity apply to urban areas as they do in other habitats. However, the fine spatial scales at which urban areas are fragmented and the altered temporal dynamics compared to non-urban areas indicate a need to apply hierarchical multi-scalar landscape ecology models to urban environments. Transferring results from landscape-scale urban biodiversity research into planning remains challenging, not least because of the requirements for urban green space to provide multiple functions. An increasing array of tools is available to meet this challenge and increasingly requires ecologists to work with planners to address biodiversity challenges. Biodiversity conservation and enhancement is just one strand in urban planning, but is increasingly important in a rapidly urbanising world

    A common biological basis of obesity and nicotine addiction

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    Smoking influences body weight such that smokers weigh less than non-smokers and smoking cessation often leads to weight increase. The relationship between body weight and smoking is partly explained by the effect of nicotine on appetite and metabolism. However, the brain reward system is involved in the control of the intake of both food and tobacco. We evaluated the effect of single-nucleotide polymorphisms (SNPs) affecting body mass index (BMI) on smoking behavior, and tested the 32 SNPs identified in a meta-analysis for association with two smoking phenotypes, smoking initiation (SI) and the number of cigarettes smoked per day (CPD) in an Icelandic sample (N=34 216 smokers). Combined according to their effect on BMI, the SNPs correlate with both SI (r=0.019, P=0.00054) and CPD (r=0.032, P=8.0 × 10<sup>−7</sup>). These findings replicate in a second large data set (N=127 274, thereof 76 242 smokers) for both SI (P=1.2 × 10<sup>−5</sup>) and CPD (P=9.3 × 10<sup>−5</sup>). Notably, the variant most strongly associated with BMI (rs1558902-A in FTO) did not associate with smoking behavior. The association with smoking behavior is not due to the effect of the SNPs on BMI. Our results strongly point to a common biological basis of the regulation of our appetite for tobacco and food, and thus the vulnerability to nicotine addiction and obesity

    Accounting for Earth's curvature and elevation in animal movement modeling

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    Animals move in three dimensions, yet movement models do not capture the third dimension when data are collected as longitude and latitude coordinates (only) and models are developed in two dimensions. Here, we ask the question to what extent topography and the shape of the Earth—its ellipsoidal shape—affect the quantification of animal movement. To answer this question, we draw from the fields of ecology and geodesy: geodesy provides the mathematics to solve the problem on the curved surface of the Earth exactly, as opposed to using a map projection, because all map projections impart a scale distortion that systematically enlarges or shrinks the distances between points in space. We provide mathematical derivations to solve this problem in two different ways and show that they are equivalent. We also provide analyses of data from pumas (Puma concolor) and humpback whales (Megaptera novaeangliae) to discuss the impact of not accounting for the macroscopic, ellipsoidal shape of the Earth nor for topography when quantifying animal movements. In short, if the vertical extent of the movement is small compared to the horizontal extent, then the difference is de minimis. Conversely, if an animal moves vertically as much, or more, than how far it moves horizontally, then the difference is not negligible. Using map-projection coordinates without corrections systematically increases and/or decreases distances and, therefore, speeds.Full Tex

    Use of glass transition temperature for stabilization of board's cracks of Eucalyptus grandis

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    The Eucalyptus grandis logs temperatures were determined and correlated with the board's cracks during steaming. Thermocouples were inserted in the logs center, registering their temperatures during steaming at 90"C. The logs were sawed and the board's cracks measured. It was concluded that: (1) the logistic S-shaped curve explains the logs temperature variation; (2) the logs with diameter of 20 to <25, 25 to <30 and 30 to <35 cm presented, respectively, 84.2"C, 73.1"C and 45.8"C in the steaming; and (3) the cracks lengths significantly decreased in logs that reached the glass transition temperature.<br>As temperaturas em toras de Eucalyptus grandis, durante a vaporização, foram determinadas e correlacionadas com as rachaduras das tábuas. Nos centros das toras foram inseridos termopares e registradas suas temperaturas durante a vaporização à 90"C. As toras foram desdobradas e as rachaduras das tábuas mensuradas. Concluiu-se que: (1) o modelo estatístico sigmoidal logístico explica a variação da temperatura nas toras; (2) as toras com 20 a <25, 25 a <30 e 30 a <35 cm de diâmetro apresentaram, respectivamente, 84,2"C, 73,1"C e 45,8"C ao final da vaporização; e (3) as rachaduras foramsignificativamente menores nas toras que atingiram a temperatura de transição vítrea
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