Xem 1-20 trên 28 kết quả Ecological value
  • The ecology of ideas of which this book is a part started to emerge in my head a long time ago. As time passed new ideas were added, some of which fl ourished, while others were unable to secure a spot in the evolving landscape. The particular combination of insights that forms the main argument of this book started taking shape after 27 November 2004. On that day our twin sons Daniel and Nestor were born. For quite some time after that I spent a lot of time holding one of them asleep in my arms. The only thing I could do in parallel was reading. So...

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  • 5 Restoration Ecology Restoration ecology is a subdiscipline of ecological engineering that has been growing out of the need and desire to add ecological value to ecosystems that have been degraded by human impacts.

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  • Human activities may seriously affect the quality of aquatic ecosystems. Pathogen organisms, nutrients, heavy metals, toxic elements, pesticides, pharmaceuticals and various other organic micropollutants enter to aquatic environment through a range of point and diffuse sources. The presence of these compounds has adverse impacts on aquatic biota. It is well recognised that the distribution and the abundance of various species in aquatic systems are directly related to the water quality and hydrological conditions....

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  • Agroecology encompasses not only aspects of ecology and agriculture, but the ecology of sustainable food production systems, including the technology and related societal and cultural values (e.g. Gliessman 1998; Altieri and Hecht 1990; Altieri 1989, 1987, 1983) to better promote healthy and functional environments for a sustainable quality of life (see also Castillo et al. 2005). To provide effective com munication regarding the status and advances in this burgeoning field, connections must be established with many disciplines including (but not limited to)...

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  • The importance of cyanobacterial toxins in drinking water sources has been highlighted by the adoption of a provisional drinking water “Guideline Value” for microcystin- LR, one of the most abundant toxins, by the World Health Organization (WHO). A number of nations have now legislated a guideline for microcystins into their drinking water regulations, with the consequent need for monitoring and analytical techniques. The Chemical Safety Committee of the WHO also has under consideration a Guideline Value for cylindrospermopsin, the other most damaging cyanobacterial toxin....

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  • Suppose we have a function f (x) where the variable x may be a vector of many dimensions. We seek the point x∗ such that f (x∗) is the maximum value among all possible f (x). This point x∗ is called the global optimum of the function f (x). It is possible that x∗ is a unique point but it is also possible that there are several points that share the maximal value f (x∗). Optimization is a field of mathematics that concerns itself with finding the point x∗ given the function f (x).

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  • 7 Conservation Genetics The Need for Conservation Biodiversity quite simply refers to all of the different life forms on our planet, and includes both species diversity and genetic diversity. There are many reasons why we value biodiversity, the most pragmatic being that ecosystems.

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  • CHAPTER TWO Recent revisions to the early Paleozoic time scale have been used to recalibrate ages assigned to stratigraphically dated paleomagnetic poles of that era. In particular, a value of 545 Ma has been used for the base of the Cambrian. Selected poles have then been used to derive apparent polar.

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  • Large lakes are important because of their size and ecological distinctiveness, as well as their economic and cultural value. Optimal management of them requires a proper understanding of anthropogenic impacts, both on the lake ecosystems, as such and on the services they provide for society. The specific structural and functional properties of large lakes, e.g. morphology, hydrography, biogeochemical cycles, and food-web structure, are all directly related to their size.

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  • The contemporary debate about the nature of human nature, centering around the implications of Darwin’s theory of evolution, is the newest chapter in a long history of explorations. Confl icting ideas about human nature have always sat at the core of philosophical debates, often educational ones. Plato and Aristotle, for example, had differing views on human nature, and thus different approaches to educational philosophy.1 So too did Descartes, Hobbes, Locke, Hume and Rousseau

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  • This volume details some of the latest advances in spectral theory and nonlinear analysis through various cutting-edge theories on algebraic multiplicities, global bifurcation theory, non-linear Schrodinger equations, non-linear boundary value problems, large solutions, metasolutions, dynamical systems, and applications to spatial ecology.

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  • Ecologically, Ennore Creek is the most strategic place where many industries started mushrooming in and around the creek in the late 1970s led to meristamatic growth affecting the fishing community (Arunagiri et al., 1998). The environmental degradation of the Ennore Creek is structurally different from the problem of pollution of the metropolitan city of Chennai. This narrow creek is one among the most polluted creeks along the Eastern Coast, which is not only receiving worldwide attention, but also one of the areas demanding intensive research.

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  • Most available literature on cockroaches deals with domestic pests and the half dozen or so other species that are easily and commonly kept in laboratories and museums. It reflects the extensive efforts undertaken to find chinks in the armor of problematic cockroaches, and the fact that certain species are ideal for physiological and behavioral investigations under controlled conditions. These studies have been summarized in some excellent books, including those by Guthrie and Tindall (1968), Cornwell (1968),Huber et al. (1990), Bell and Adiyodi (1982a), and Rust et al. (1995).

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  • The authors and contributors to this report acknowledge the Indigenous Traditional Owners of Country throughout Northern Australia, and their right to speak for Country. The authors are recipients of an ARC Linkage Grant focused on investigating connectivity conservation issues in various regions, including Northern Australia. Some of the outcomes from that research were drawn upon for this report.

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  • Knowing nature is a complex, multiple, and highly political process. This is clearly illustrated by looking at the knowledge and management of a piece of land, seemingly isolated but impacting and impacted by decision- making processes, politics, and technology around the world. A barren stretch of ground in the Sahelian region of West Africa holds diverse meanings to different people and institutions. Livestock herders value it for its proximity to a water point and for the grass it will grow once the rains come.

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  • Volunteers Are a Valuable Financial Resource. A volunteer’s time is an important resource for many charities and congregations, especially those that do not have the money to hire labor to carry out certain tasks. Volunteer time is comparable to a monetary donation. Independent Sector, a national advocate for the nonprofit sector, computes annually an equivalent average hourly wage for a volunteer’s time. The calculation is derived from the average hourly wage of nonagricultural workers plus 12 percent for fringe benefits. By this calculation, the typical 2002 volunteer value was $16.

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  • An extensive body of research suggests that psychological assets do confer resilience and protection and do so at both an individual and an ecological level (Bartley 2006; Fagg et al 2006; Sacker and Schoon 2007). The optimism, self esteem, self efficacy and interest in others that contribute to a child’s success at school are also characteristics of resilient neighbourhoods and communities, where norms of trust, tolerance, support, participation and reciprocity may provide some protection from the effects of deprivation.

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  • Sea Lamprey Objectives Reduce sea lamprey abundance to allow the achievement of other fish community objectives. Obtain a 75% reduction in parasitic sea lampreys by the year 2000 and a 90% reduction by the year 2010. Species Diversity Objective Recognize and protect the array of other indigenous fish species because they contribute to the richness of the fish community. These fish – cyprinids, rare ciscoes, suckers, burbot, gar, and sculpins- are important because of their ecological significance; intrinsic value; and social, cultural, and economic benefits.

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  • Although farmers do not receive any support from society for the contribution of the dehesa to welfare of society and the environment, they still conserve, prune and reforest oaks to maintain fruit production to feed and fatten Iberian pigs during the montanera or pannage. The ability of the Iberian pig breed to feed on acorns is a key feature in maintaining the dehesa.

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  • Due to the growing importance of forest goods and services an increasing amount of information is being collected on the ecological and also on the socio-economic value of goods and services provided by forests. However, much of this information is collected and presented at incompatible scales or it has been classified differently. In order to make comparative ecological or economic analysis possible, standardized frameworks for assessing the importance of forest goods and services are needed.

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