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261.
Willem Odendaal 《Journal of Land Use Science》2020,15(2-3):457-476
ABSTRACT This paper is about mining under communal ownership which makes this kind of mining a new mining frontier. The newness of the frontier is that it has introduced a series of institutional complexities that is uncommon to artisanal and large-scale mining. Mining companies have to negotiate deals with communities and their leaders to be able to prospect for mineral resources. We also argue that the state’s environmental legislation is poorly harmonised with the prevalent conditions in communal areas where mining is gaining greater importance. Legislation remains silent on the rights of those living on communal land. These rights remain in a state of confusion with often negative effects on the local communities who are exposed to a number of duplicating development programmes and legislative structures. The aim of this paper is to explore the dynamics communal mining in the Kunene Region in north-western Namibia. 相似文献
262.
263.
The possibility of finding new medicines from natural sources is one of the more commonly cited reasons for preserving biodiversity,
and employing indigenous knowledge of traditional healing remedies greatly increases the likelihood of discovering these hidden
medicinal compounds. The main difficulties in using natural products as a source for pharmaceutical lead compounds involve
separating the plethora of compounds from the original extract, as well as the gamble of time and money invested in an activity
that may not yield a novel compound. However, while these difficulties exist, the potential of natural products still far
outweighs the limitations of the simple structures and known modes of action of synthetic lead compounds. As such, the production
of novel medicines, particularly for cancer and human immunodeficiency virus (HIV) treatments as well as the inhibition of
antibiotic-resistant bacteria, now requires the utilization of natural products. This paper provides a review of the current
methods used in elucidating pharmaceutical lead compounds from natural sources, focusing on plant samples in particular. 相似文献
264.
Sovereign financial disaster risk management: The case of Mexico 总被引:1,自引:0,他引:1
Victor Cardenas Stefan Hochrainer Reinhard Mechler Georg Pflug Joanne Linnerooth-Bayer 《Environmental Hazards》2007,7(1):40-53
In 2006, Mexico became the first transition country to transfer part of its public-sector natural catastrophe risk to the international reinsurance and capital markets. The Mexican case is of considerable interest to highly exposed transition and developing countries, many of which are considering similar transactions. Risk financing instruments can assure governments of sufficient post-disaster capital to provide emergency response, disaster relief to the affected population and repair public infrastructure. The costs of financial instruments, however, can greatly exceed expected losses, and for this reason it is important to closely examine their benefits and alternatives. This paper analyzes the Mexican case from the perspective of the risk cedent (the Ministry of Finance and Public Credit), which was informed by analyses provided by the International Institute for Applied Systems Analysis (IIASA). The rationale for a government to insure its contingent liabilities is presented along with the fiscal, legal and institutional context of the Mexican transaction. Using publicly available data, the paper scrutinizes the choice the authorities faced between two different risk-transfer instruments: reinsurance and a catastrophe bond. Making use of IIASA's catastrophe simulation model (CATSIM), this financial risk management decision is analyzed within the context of a public investment decision. 相似文献
265.
Economic resilience to natural and man-made disasters: Multidisciplinary origins and contextual dimensions 总被引:4,自引:0,他引:4
Economic resilience is a major way to reduce losses from disasters. Its effectiveness would be further enhanced if it could be precisely defined and measured. This paper distinguishes static economic resilience—efficient allocation of existing resources—from dynamic economic resilience—speeding recovery through repair and reconstruction of the capital stock. Operational definitions are put forth that incorporate this important distinction. The consistency of the definitions is examined in relation to antecedents from several disciplines. The effectiveness of economic resilience is evaluated on the basis of recent empirical studies. In addition, its potential to be enhanced and eroded is analyzed in various contexts. 相似文献
266.
Growing interest in green products has provided fresh impetus to the research in the field of renewable materials. Plant fibers are not only renewable but also light in weight and low in cost. Polymer composites manufactured using them find applications in diverse fields such as automobiles, housing, and furniture. However, their hydrophilic nature and inadequate adhesion with matrix limits their use in high performance applications. In this study, a novel method for improving adhesion characteristics of natural fibers has been developed. This method is carried out by treating hemp fibers with a fungus: Ophiostoma ulmi, obtained from elm tree infected with Dutch elm disease. Treated fibers showed improved acid–base characteristics and resistance to moisture. Improved acid–base interactions between fiber and resin are expected to improve the interfacial adhesion, whereas improved moisture resistance would benefit the durability of the composites. Finally, composites were prepared using untreated/treated fibers and unsaturated polyester resin. Composites with treated fibers showed slightly better mechanical properties, which is most probably due to improved interfacial adhesion. 相似文献
267.
Since tidal marshes and estuaries cover large areas of the world's coasts and exhibit a very high net primary productivity, they offer a most important food source for an ever increasing world population. The food web of numerous estuaries and coastal waters is based on the primary productivity of coastal marshes that constitute centers of solar energy fixation and an important link in the mineral cycles. The fixed carbon and minerals enterthe water primarily as detritus where a complex food web makes them accessible to commercially important fish and benthic communities. With the launch of LANDSAT, NOAA-2, and Skylab, relatively high resolution spacecraft data became available for mapping and inventorying tidal marshes and their productivity on a global scale. Upwelling regions that attract large fish populations as well as other coastal water properties relating to the presence of finfish, Crustacea, and shellfish could be identified and observed. Using multispectral analysis techniques, classification accuracies greater than 80 percent have been obtained for most marsh plant species, and greater than 90 percent for key types such asSpartina alterniflora, which is the primary producer in large tide marshes of the coastal eastern USA. The capacity of remote sensors on spacecraft such as NOAA-2, LANDSAT, and Skylab to assess coastal food resources on a global scale is discussed from the point of view of resolution, classification accuracy, and cost effectiveness. 相似文献
268.
This paper explores the positive aspects of collaboration in natural resources. Its purpose was to investigate participants'
overall attitudes about keys to successful collaboration. The sample for the study consisted of 671 participants involved
in 30 collaborative initiatives (CI) with the Forest Service. Using a mailed questionnaire, this study profiled the collaborative
initiatives investigating purpose, problems addressed, groups involved, and years in existence. Respondents were queried on
their overall perspectives on keys to successful collaboration. A total of more than 300 comments was collected from respondents
and six categories emerged: development, information exchange, organizational support, personal communication, relationships/team
building, and accomplishments. Continued research will need to explore the short- and long-term impacts of collaboration in
natural resources. 相似文献
269.
Spatial pattern and persistence of historical fire boundaries in southern interior British Columbia 总被引:2,自引:0,他引:2
Geraldine J. Jordan Marie-Josée Fortin Kenneth P. Lertzman 《Environmental and Ecological Statistics》2008,15(4):523-535
Recent ecosystem and fire management research aims to quantify, model and understand historical fire disturbances focusing
on their frequency, size and distribution. Less attention, however, has been paid to fire boundaries and their location on
the landscape. Our study presents a spatial method to quantify the location, pattern and persistence of historical fire boundaries
using tree ring fire scar data in the lower Stein watershed (British Columbia). Data from Pinus ponderosa and Pseudotsuga menziesii collected in 35 one-hectare plots over a 412-hectare study area were analyzed for the period between 1879 and 1947 using
local spatial statistics and boundary detection techniques. Results of the analysis using local spatial statistic Moran’s
I showed significant clustering of boundaries near topographic breaks. To determine and test whether fire boundaries between
plots were persistent, we used boundary detection methods and developed a spatially restricted randomization test. The results
revealed that out of 86 possible boundary links, 8 were significantly persistent (P < 0.025) while another 8 were significantly rare (P < 0.025). These spatial methods can help determine the historical spatial configuration of persistent boundaries and can
be used to maintain natural forest dynamics.
相似文献
Geraldine J. JordanEmail: |
270.
This paper examines the effect that endangered species regulation has on natural resource development. Specifically, we use data from competitive auctions to estimate the effect that land-use regulation protecting endangered caribou in the Canadian province of Alberta has on the price producers pay for the right to extract oil. We exploit a regression discontinuity design to evaluate how prices differ along regulation boundaries that constrain resource development. The auction format and the regulation discontinuity allow us to measure the total cost of the regulation. We find that producers pay 24% less on average for oil leases that are regulated and that the total net present value cost of the regulation exceeds $1.15 billion for leases sold between 2003 and 2012, all of which is borne by the government. In spite of these costs, the populations of endangered caribou remain in widespread decline. 相似文献