Expensive Process (expensive + process)

Distribution by Scientific Domains


Selected Abstracts


The Cost Efficiency of Wild Dog Conservation in South Africa

CONSERVATION BIOLOGY, Issue 4 2005
P. A. LINDSEY
crianza de especies cinegéticas; financiamiento de donantes; Lycaon pictus; metapoblación; reintroducción Abstract:,Aside from Kruger National Park, no other suitable reserves of sufficient size exist in South Africa that will hold a viable population of wild dogs (Lycaon pictus). Consequently, conservation efforts have been focused on creating a metapopulation through a series of wild dog reintroductions into isolated fenced reserves. Additional potential exists for conserving wild dogs on private ranch land. Establishing the metapopulation was an expensive process, accounting for approximately 75% of the US$380,000 spent on wild dog conservation in South Africa during 1997-2001. The principal goal of the metapopulation project was to reduce the risk of catastrophic population decline. Now that this has been achieved, we developed a uniform cost-efficiency index to estimate the cost efficiency of current and potential future conservation strategies in South Africa. Conserving wild dogs in large protected areas was predicted to be the most cost-efficient conservation strategy (449 packs/$100,000 expenditure). Establishing the metapopulation has been less cost efficient (23 packs/$100,000), and expansion of the metapopulation was predicted to be even less cost efficient if predation by wild dogs results in additional costs, as is to be expected if private reserves are used for reintroductions (3-13 packs/$100,000). Because of low logistical costs, conserving wild dogs in situ on private ranch land was potentially more cost efficient than reintroducing wild dogs (14-27 packs/$100,000). We recommend that donor funding be used to reintroduce wild dogs into transfrontier parks, when they are established, to maintain the existing metapopulation and to establish conservation programs involving wild dogs on private ranch land. Investing in the expansion of the metapopulation should be limited to state-owned nature reserves willing to carry predation costs without compensation. Resumen:,Además del Parque Nacional Kruger, en África del Sur no existen otras reservas de suficiente tamaño como para mantener una población viable de perros salvajes (Lycaon pictus). En consecuencia, los esfuerzos de conservación se han enfocado en la creación de una metapoblación por medio de una serie de reintroducciones en pequeñas reservas cercadas. Hay un potencial adicional para la conservación de perros salvajes en terrenos privados. El establecimiento de la metapoblación fue un proceso costoso, ,75% de US $380,000 que fueron gastados en la conservación de perros salvajes entre 1997 y 2001 en África del Sur. La meta principal del proyecto de metapoblación fue la reducción del riesgo de una declinación catastrófica de la población. Ya que esto se ha logrado, desarrollamos un índice de rentabilidad uniforme para estimar la rentabilidad de las actuales y potenciales estrategias de conservación en África del Sur. Se predijo que la estrategia de conservación de más rentable (449manadas/$100,000 de gasto) era la conservación de perros salvajes en áreas protegidas grandes. El establecimiento de la metapoblación ha sido menos rentable (23 manadas/$100,000), y se predijo que la expansión de la metapoblación sería aun menos rentable si la depredación por perros salvajes resulta en costos adicionales, como se esperaría si se utilizan reservas privadas para las reintroducciones (3-13 manadas/$100,000). Debido a los bajos costos de logística, la conservación de perros salvajes in situ en terrenos privados fue potencialmente más rentable que reintroducir a los perros salvajes (14-27 manadas/$100,000). Recomendamos que el financiamiento de donantes sea utilizado para reintroducir perros salvajes en parque transfronterizos, cuando sean establecidos, para mantener a la metapoblación existente y para establecer programas de conservación que involucren a perros salvajes en terrenos privados. La inversión en la expansión de la metapoblación deberá limitarse a reservas naturales propiedad del estado que estén dispuestas a absorber los costos de la depredación sin ser compensadas. [source]


A two-stage convective air and vacuum freeze-drying technique for bamboo shoots

INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 6 2005
Yanyang Xu
Summary To obtain dehydrated bamboo shoot slices of high quality, a two-stage hybrid method of drying was tested to see if it could be cost-effective. While freeze-drying provides the best quality bamboo shoot it is a very expensive process. In this study, the drying techniques (a) hot airflow drying followed by vacuum freeze drying and (b) the reverse of the process (a) were examined. The quality of bamboo shoots dried by process (b) was found to be approximately equal to that of freeze-dried bamboo shoots but at a significantly lower cost. This paper reports results comparing the two processes in terms of energy consumption and the physico-chemical properties of the dried bamboo. [source]


Removal of organic contaminants in paper pulp effluents by AOPs: an economic study

JOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 5 2002
Montserrat Pérez
Abstract The degradation of the organic content of a bleaching Kraft mill effluent was carried out using Advanced Oxidation Processes (AOPs). The study was focused on the identification of the AOP, or combination of AOPs, that showed the highest efficiency together with the lowest cost. Direct UV photolysis (UV), TiO2 assisted-photocatalysis (TiO2/UV), Fenton, Fenton-like, and photo-Fenton reactions (Fe(II)/H2O/UV), UV-assisted ozonation (O3/UV) and addition of Fe2+ and/or H2O2 to the TiO2/UV and the O3/UV systems, were used for the degradation of a conventional cellulose bleaching effluent. The effluent was characterized by the general parameters TOC, COD and color, and analyzed for chlorinated low molecular weight compounds using GC,MS. The costs of the systems per unit of TOC reduction were compared. Fenton, Fenton-like and photo-Fenton reactions achieved better levels of TOC degradation than photocatalysis and with lower cost's than photocatalytic treatments. Ozonation is an effective but rather expensive process. The use of UVA light, however, increased the effectiveness of ozonation with a significant decrease (>25%) in the operational cost. © 2002 Society of Chemical Industry [source]


Field trial of serially passaged isolates of BYDV-PAV overcoming resistance derived from Thinopyrum intermedium in wheat

PLANT BREEDING, Issue 3 2006
F. Chain
Abstract Barley yellow dwarf disease (BYDD) is one of the main viral diseases of small grain cereals. This disease, reported on numerous plant species of the Poaceae family, is caused by a complex of viral species including the species Barley yellow dwarf virus -PAV (BYDV-PAV, family Luteoviridae, genus Luteovirus), frequently found in western Europe. Resistance sources towards BYDD are scarce. Indeed, breeding-resistant genotypes is a long and expensive process. Thus, estimating the durability of the resistance genes before the achievement of selection would be an asset for breeders. One isolate of BYDV-PAV has been serially passaged on two hosts, ,Zhong ZH' and ,TC14', carrying a gene for partial resistance. The resulting viral population showed an increase of the speed of development of the infection in controlled conditions. In this study, these viral populations were evaluated in a 3-year field trial, including a susceptible host, ,Rendezvous', and a host carrying the resistance gene of ,TC14' in a ,Rendezvous' background, to assess the effect of serial passages in field conditions. Results indicate that isolates issued from serial passages on hosts carrying a gene for partial resistance induced increased damage in field conditions when compared with the initial isolate. Yield losses are mainly due to a decrease of the number of kernels per square metre. The interest on using partial resistance gene to control BYDD is discussed. [source]