The yellow pages service of GTE SuperPages enables Web users to flexibly search through liitings of 11 million businesses in over 17000 categories. To achieve the flexibility desired it uses an Information Retrieval (IR) engine to search through complex listing objects. The objects themselves are stored in an object database. The use of the IR engine enables us to create an index that spans all...

Animal behavior is often altruistic. In the frame of the theory of natural selection, altruism can only exist under specific conditions like kin selection or reciprocal cooperation. We show that reciprocal cooperation, which is generally invoked to explain non-kin altruism, requires very restrictive conditions to be stable. Some of these conditions are not met in many cases of altruism observed...

Social responsibility of pastoralists is one of the most important elements and an integral part of rangelands exploitation. It not only leads to better rangeland health, but also enhances exploiters’ satisfaction for continuous sustainable utilization of rangelands. The present study investigated the role of social responsibility in rangelands condition in nomadic areas of Gonbad County in Gol...

Rangelands are the main sources of forage for livestock feeding by localpeople. Beside forage production, rangeland ecosystems provide many other goods andservices such as medicinal plants, recreation, soil and water conservation, wildlife habitat,fishing, hunting, hiking, etc. Nevertheless, there are no much information about the waythat local communities think about the rangelands goods and s...

Rangelands are uncultivated lands that include grasslands, savannahs, steppes, shrub lands, deserts and tundra. The native vegetation on rangelands is predominantly grasses, forbs and shrubs (Kothmann, 1974). Rangelands cover 31 percent of the land surface area of the United States (Havstad et al., 2009), and up to half of the land surface area worldwide (Lund, 2007). Most land areas that are n...

This study describes the components of available forage in Vahregan watershed, Central Iran and highlight issues relating to forage endowment and environmental dynamics. In this study, proper use factor and palatability models and their components use to develop the model of available forage and measure it. The components climatic, topography, land systems, vegetation, land use and grass and sh...

Models that seek to guide decisions on policy in rangelands must address the close links between ecological, economic, and social processes, and the adaptation of participants through time. We used an agent-based modeling approach to implement a parsimonious conceptual model of rangelands that includes biophysical processes central to the functioning of rangelands, commercial enterprises, and i...

Recognition of byproducts and their exploiting economic evaluation is one of basic requirements in documenting prospect of rangelands utilization. In this regard, the present study was performed to estimate the economic indices of exploiting byproducts production in Varnasa rangelands, Naghadeh, Iran. For this purpose, the economic data for calculating economic indices were collected after samp...

To reduce dependence on foreign oil reserves, there has been a push in North America to develop alternative domestic energy resources. Relatively undeveloped renewable energy resources include biofuels and wind and solar energy, many of which occur predominantly on rangelands. Rangelands are also key areas for natural gas development from shales and tight sand formations. Accordingly, policies ...

assignment of additional exploitation of rangelands including ecotourism to the natives in addition to compensation for residents is thought to prevent further destruction of the pastures. in doing so, the local communities are financially supported and so their participation rate will be higher in protecting and restoring of rangelands. lasem watershed is one of iran's rangelands with gre...