906 resultados para Total economic value


Relevância:

90.00% 90.00%

Publicador:

Resumo:

The production of fish and net economic return in pangasiid catfish (Pangasius hypophthalmus) monoculture and polyculture with silver carp (Hypophthalmichthys molitrix) in farmers' ponds were assessed. The experiment was arranged in three treatments each with three replications. The ponds were stocked with 30,000 fishes per hectare. In treatment 1 (T1) pangasiid catfish only, in treatment 2 (T2) pangasiid catfish and silver carp at the ratio of 1:1, and in treatment 3 (T3) pangasiid catfish and silver carp at the ratio of 2:1 were stocked. At harvest, production of fish was found significantly (p<0.05) different among the treatments, highest in T1 and lowest in T2. Though the total biomass production and total economic return was significantly highest in T1 than in T2 and T3, the net economic return was lowest because of the required highest input costs especially for supplemental feed and fingerlings, resulted the highest cost per unit yield (CPY in Tk/kg) in T1. Highest cost for supplemental feed required in T1 was due to highest quantity of feed required for the highest number of pangasiid catfish stocked in that treatment. The findings of the present study suggest that though monoculture of pangasiid catfish give higher fish biomass production but polyculture with silver carp is environmentally good and economically profitable.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

The article presents the forestry, fishery and ecological values of mangroves. Studies on the measurement of the economic value of mangroves that were conducted in Thailand, Indonesia and Ecuador are also presented.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Purpose: Although business models that deliver sustainability are increasingly popular in the literature, few tools that assist in sustainable business modelling have been identified. This paper investigates how businesses might create balanced social, environmental and economic value through integrating sustainability more fully into the core of their business. A value mapping tool is developed to help firms create value propositions better suited for sustainability. Design/methodology/approach: In addition to a literature review, six sustainable companies were interviewed to understand their approaches to business modelling, using a case study approach. Building on the literature and practice, a tool was developed which was pilot tested through use in a workshop. The resulting improved tool and process was subsequently refined through use in 13 workshops. Findings: A novel value mapping tool was developed to support sustainable business modelling, which introduces three forms of value (value captured, missed/destroyed or wasted, and opportunity) and four major stakeholder groups (environment, society, customer, and network actors). Practical implications: This tool intends to support business modelling for sustainability by assisting firms in better understanding their overall value proposition, both positive and negative, for all relevant stakeholders in the value network. Originality/value: The tool adopts a multiple stakeholder view of value, a network rather than firm centric perspective, and introduces a novel way of conceptualising value that specifically introduces value destroyed or wasted/ missed, in addition to the current value proposition and new opportunities for value creation. © Emerald Group Publishing Limited.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Invasive alien species have become one of the most serious environmental issues in the world. Data of taxon, origin, pathway, and environmental impacts of invasive alien microorganisms, invertebrates, amphibians and reptiles, fish, birds, mammals, herbs, trees, and, marine organisms in terrestrial, aquatic, and marine ecosystems of China were analyzed during 2001 and 2003, based on literature retrieval and field survey. There were 283 invasive alien species in China, and the number of species of invasive alien microorganisms, aquatic plants, terrestrial plants, aquatic invertebrates, terrestrial invertebrates, amphibians and reptiles, fish, and mammals were 19, 18, 170, 25, 33, 3, 10, and 5, respectively. The proportion of invasive alien species originated from America, Europe, Asia, Africa, and Oceania were 55.1, 21.7, 9.9, 8.1, and 0.6%, respectively. Methods for estimation of direct economic losses to agriculture, forestry, stockbreeding, fishery, road and water transportation, storage, water conservancy, environment and public facilities, and human health were established. Methods for estimation of indirect economic losses caused by invasive alien species to service functions of forest ecosystems, agricultural ecosystems, grassland ecosystems, and wetland ecosystems were also established. The total economic losses caused by invasive alien species to China were to the time of USD 14.45 billion, with direct and indirect economic losses accounting for 16.59% and 83.41% of total economic losses, respectively.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

近年来,随着对作物重茬障碍原因的深入研究,植物的化感作用越来越受到国内外众多学者的重视。花椒(Zanthoxy piperitum.)为芸香科植物,是一种收益早、用途广、价值高的经济树种,是川西干旱河谷地区的重要经济作物,其连作障碍也倍受关注,系统研究花椒化感作用将有助于理解和最终解决花椒连作障碍问题。本文首先通过萃取、层析等方法分离花椒主效化感成分;通过外加不同浓度的花椒叶水浸液研究了对土壤氮素养分循环的影响;研究了花椒叶水浸液对苜蓿生理生化、光合作用、氮素养分吸收的影响,并对外施氮肥对这种化感影响的缓解作用做了研究;研究了花椒化感潜力对全球变化——UV-B增强辐射的响应。主要研究结果如下: 1.用不同极性的有机溶剂对花椒叶水浸液浓缩浸膏萃取、柱层析,结合生物活性检测,分离得到主效化感作用组分的一种化感物质——对甲氧基苯酚。采用该物质纯品进行生物活性检测,证明其具有化感作用。 2.花椒叶水浸液处理土壤30天后,土壤硝态氮、铵态氮、无机氮(硝态氮+铵态氮)与对照相比,随着花椒叶水浸液浓度的增加呈现降低的趋势,其中土壤铵态氮含量显著降低,而硝态氮含量的变化则不显著,无机氮含量也显著降低。土壤脲酶和蛋白酶的活性与无机氮含量的变化趋势相同。随着花椒叶水浸液浓度的增加,氨化细菌数量显著降低,固氮菌的数量变化不显著,硝化细菌和反硝化细菌数量有减少的趋势。60天后,硝态氮含量、铵态氮含量、无机氮随水浸液浓度增加的变化趋势与30天时相似;随着花椒叶水浸液浓度的增加,氨化细菌、固氮菌的数量显著减少,硝化细菌数量、反硝化细菌数量仍呈减少趋势;土壤脲酶、蛋白酶活性与第30天的变化趋势相同。第60天与第30天的结果相比,相同水浸液浓度处理的硝态氮、铵态氮、无机氮均有下降的趋势,但除了25g.L-1水浸液处理的外,其它相同浓度的处理间差异均不显著;除了12.5 g.L的处理外土壤脲酶活性均呈增强的趋势;蛋白酶活性都有不同程度的增加;花椒叶水浸液处理的土壤硝化细菌和反硝化细菌数量呈增加趋势。 3.随着花椒叶水浸液浓度的增加,显著抑制了苜蓿根长、地上地下生物量、叶绿素含量、叶片中可溶性蛋白的含量,净光合速率。苜蓿体内四种抗氧化酶(POD、SOD、CAT、APX) 活性随着水浸液浓度的增加而降低,而丙二醛含量则增加。苜蓿氮初级同化相关酶硝酸还原酶(NR)、谷氨酰合成酶(GS)、谷氨酸脱氢酶(GDH)的活性随着水浸液浓度的增加受到不同程度的影响。总的来说,苜蓿硝酸还原酶、谷氨酰合成酶的活性受到抑制,而谷氨酸脱氢酶活性的变化则比较复杂,根呈先降低后增加的趋势,叶片则无显著变化。外施两种不同浓度的硝酸铵氮肥后,对12.5、25 g.L-1花椒叶水浸液处理的苜蓿化感作用有显著的缓解作用,表现在株高、生物量、光合作用等方面,大多达到与对照(0 g.L-1)未施氮肥无显著差异的水平,而对50 g.L-1水浸液处理的苜蓿幼苗,虽有一定的缓解作用,但这种作用均未达到与对照(0 g.L-1)未施氮肥时无显著差异的水平。 4. UV-B增强辐射处理花椒后,花椒的化感潜力显著增强。花椒叶片内UV-B吸收物质的含量和总酚含量均显著增加。 In recent years, with profound research on the reasons of continuous cropping obstacles, allelopathy received increasing attention to many scholars at home and abroad. Zanthoxy bungeanum as a Rutaceae plant is a high economic value species which gains early and uses widely. Zanthoxylum is an important economic crop in the arid valley of western Sichuan region, and its not even has received much concern for the continuous cropping obstacles. The systematic study of allelopathy of Zanthoxylum will contribute to the understanding and final settlement of this issue. The major allelopathic composition was separated through the extraction, chromatography combined with other methods. The impact on soil nutrient cycling was also studied through the addition of different concentrations of water extracts of Zanthoxylum. Furthermore, the effects of water extracts of Zanthoxylum leaves on alfalfa leaf physiological and biochemical indexes, photosynthesis, soil enzymes and nutrient uptake of nitrogen and the mitigation of allelopathy through using external fertilizer were studied to put forward scientific resolvent for Zanthoxylum continuous cropping obstacles .The response of allelopathic potential of Zanthoxylum to global change - UV-B enhanced radiation was studied . The main findings are as follows: 1. Through extraction with different polar organic solvents on concentrated water extract of Zanthoxylum leaf and then using column chromatography combined with detection of biological activity, one of the main allelopathic components- methoxy-phenol was isolated. The biological activity testing of the pure material of methoxy-phenol proved that it does have allelopathic potential. 2. Thirty days after treating soil with water extract of Zanthoxylum leaf, as compared with the control, the contents of soil nitrate, ammonium, nitrate plus ammonium nitrogen showed a trend of decrease with the increase of the concentration of water extract whereas the content of ammonium nitrogen showed a significant reduction, and the content of nitrate did not change significantly, the content of nitrate plus ammonium nitrogen also showed a significant (P <0.05) redction. The activity of soil urease and protease showed the same trend as the content of nitrate nitrogen plus ammonium nitrogen. With the increase in the concentration of water extract, the number of ammonification bacteria significantly reduced but nitrogen-fixing bacteria did not change significantly and there was a decreasing trend in the number of nitrifying bacteria and denitrifying bacteria. Sixty days after the treatment, with the increase in solution concentration of water extract of Zanthoxylum leaf, the content of nitrate、 ammonium nitrogen, nitrate plus ammonium nitrogen showed a similar change trend to 30 days’; the number of ammonification bacteria, nitrogen-fixing bacteria significantly reduced ; the number of nitrifying bacteria, denitrifying bacteria was still an downward trend; the activity of soil urease and protease showed the same trend as the 30th days’. Compared to the results of the 30th days’, the content of nitrate, ammonium, nitrate plus ammonium nitrogen showed a decrease trend between the treatment of same concentration, but there was no significant difference except the treatment of 25g.L-1 between the same concentration; the activity of soil urease showed enhanced trend except the treatment of 12.5 g.L-1; the activity of protease increased to varying degrees; the number of ammonification bacteria、 nitrifying bacteria and denitrifying bacteria were growing while nitrogen-fixing bacteria reduced.. 3. With the increase of the concentration of water extract of Zanthoxylum leaf, the water extract significantly inhibited the root length, aboveground biomass, content of chlorophyll and soluble protein in leaf and net photosynthetic rate. The activity of four antioxidant enzymes (POD, SOD, CAT, APX) reduced with the increase in concentration of the water extract but the content of MDA increased. The activity of enzymes related to primary nitrogen assimilation such nitrate reductase (NR), glutamyl synthetase (GS), glutamate dehydrogenase (GDH) were subject to different degrees with an increase in the concentration of water extracts. In general, the activity of nitrate reductase, glutamyl synthetase were inhibited, while change in the activity of glutamate dehydrogenase was more complex. The activity of glutamate dehydrogenase in leaf was first reduced and then increase,but did not change significantly in root. After using two external different concentrations of nitrogen fertilizer, there was a significant mitigation in inhibiton in plant height, biomass, photosynthesis, etc. in the treatment of 12.5,25 gL-1 of water extract of Zanthoxylum leaf, and most of these indexes showed no significant difference with the control (0 g.L-1, no external fertilizer was added) .Although there showed a certain degree of ease in the treatment of 50 g.L-1 , there was still a significant difference compared with the control (0 gL-1) in which no external fertilizer was used. 4.The allelopathic potential of Zanthoxylum positively responded to enhanced UV-B significantly. The content of UV-B absorbing compounds and the total phenol also significant increased.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

This study assesses the value of restoring forested wetlands via the U.S. government's Wetlands Reserve Program (WRP) in the Mississippi Alluvial Valley by quantifying and monetizing ecosystem services. The three focal services are greenhouse gas (GHG) mitigation, nitrogen mitigation, and waterfowl recreation. Site- and region-level measurements of these ecosystem services are combined with process models to quantify their production on agricultural land, which serves as the baseline, and on restored wetlands. We adjust and transform these measures into per-hectare, valuation-ready units and monetize them with prices from emerging ecosystem markets and the environmental economics literature. By valuing three of the many ecosystem services produced, we generate lower bound estimates for the total ecosystem value of the wetlands restoration. Social welfare value is found to be between $1435 and $1486/ha/year, with GHG mitigation valued in the range of $171 to $222, nitrogen mitigation at $1248, and waterfowl recreation at $16. Limited to existing markets, the estimate for annual market value is merely $70/ha, but when fully accounting for potential markets, this estimate rises to $1035/ha. The estimated social value surpasses the public expenditure or social cost of wetlands restoration in only 1 year, indicating that the return on public investment is very attractive for the WRP. Moreover, the potential market value is substantially greater than landowner opportunity costs, showing that payments to private landowners to restore wetlands could also be profitable for individual landowners. © 2009 Elsevier B.V.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

There is a need for coordinated research for the sustainable management of tropical peatland. Malaysia has 6% of global tropical peat by area and peatlands there are subject to land use change at an unprecedented rate. This paper describes a stakeholder engagement exercise that identified 95 priority research questions for peatland in Malaysia, organized into nine themes. Analysis revealed the need for fundamental scientific research, with strong representation across the themes of environmental change, ecosystem services, and conversion, disturbance and degradation. Considerable uncertainty remains about Malaysia's baseline conditions for peatland, including questions over total remaining area of peatland, water table depths, soil characteristics, hydrological function, biogeochemical processes and ecology. More applied and multidisciplinary studies involving researchers from the social sciences are required. The future sustainability of Malaysian peatland relies on coordinating research agendas via a ‘knowledge hub’ of researchers, strengthening the role of peatlands in land-use planning and development processes, stricter policy enforcement, and bridging the divide between national and provincial governance. Integration of the economic value of peatlands into existing planning regimes is also a stakeholder priority. Finally, current research needs to be better communicated for the benefit of the research community, for improved societal understanding and to inform policy processes.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Lumpfish, or lumpsucker, Cyclopterus lumpus (Linnaeus, 1758) is widely distributed in the North Atlantic Ocean. It has a considerable economic value and substantial fisheries occur in several North Atlantic regions owing to the use of its fully ripe internal egg masses in the ovaries as an alternative to sturgeon caviar. Despite being intensively fished in several locations, biological knowledge is limited and no genetic structure information is available. In this study, the stock structure of C. lumpus was investigated across the North Atlantic using ten microsatellite loci. Out of ten loci, two exhibited higher level of differentiation but their inclusion/ exclusion from the analyses did not drastically change the observed genetic pattern. A total of three distinct genetic groups were detected: Maine-Canada-Greenland, Iceland-Norway and Baltic Sea. These results, discussed in terms of origin of differentiation, gene flow, and selection, showed that gene flow was rather limited among the detected groups, and also between Greenland and Maine-Canada.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

In ecotoxicology a major focus is in the aquatic environment, not only because it presents a great economic value to man but it is an ecosystem widely affected by the growing anthropogenic pollution. Most of the studies performed relate to adverse effects in development, reproductive or endocrine disruption but little is known about the possible effects in bone formation and skeletal development. In this study, we set out to evaluate the effects of 8 aquatic pollutants on the skeletal development using an in vivo system, the zebrafish larvae aged 20 days post-fertilization, through chronic exposure. Several endpoints were considered such as the cumulative mortality, total length, occurrence of skeletal deformities and marker gene expression. We were able to establish LD50 values for some pollutants, like 3-methylcholanthrene, lindane, diclofenac, cobalt and vanadate and found that the total length was not affected by any of the pollutants tested. Cobalt was the most harmful chemical to affect hatching time, severely affecting the ability of the zebrafish embryos to hatch and overall the number of deformities increased upon exposure to tested chemicals but no patterns of deformities were identified. We also propose that 3-methylcholanthrene has an osteogenic effect, affecting osteoblast and osteoclast function and that op levels can act as a mediator of 3-methylcholanthrene toxic stress to the osteoblast. In turn we found naphthalene to probably have a chondrogenic effect. Our results provided new insights into the potential osteotoxicity of environmental pollutants. Future studies should aim at confirming these preliminary data and at determining mechanisms of osteotoxicity.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Tese de Doutoramento, Geografia (Ordenamento do Território), 25 de Novembro de 2013, Universidade dos Açores.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

This thesis is a Field Lab project requested by the organizer of the Volta a Portugal em Bicicleta 2015, Podium Events. Its purpose is to determine the economic impact of the event for the 21 host economies and Portugal as a whole. The Volta started in Viseu and ended in Lisboa, and lasted for two weeks from the 29th July until the 8th August. Results were computed by accessing data provided by the different economic agents involved in the event (spectators, attendees and organizer), through face-to-face surveys and contact via e-mail. The Volta generated a total economic impact of €76.261.876. Keywords: Cycling,

Relevância:

90.00% 90.00%

Publicador:

Resumo:

This thesis is a Field Lab project requested by the organizer of the Volta a Portugal em Bicicleta 2015, Podium Events. Its purpose is to determine the economic impact of the event for the 21 host economies and Portugal as a whole. The Volta started in Viseu and ended in Lisboa, and lasted for two weeks from the 29th July until the 8th August. Results were computed by accessing data provided by the different economic agents involved in the event (spectators, attendees and organizer), through face-to-face surveys and contact via e-mail. The Volta generated a total economic impact of €76.261.876.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

En Colombia el sector pecuario, es uno de los más representativos para el crecimiento y sostenibilidad de la economía del país. El sector aporta el 9% del PIB, sus ventas al exterior representan el 21% del valor de las exportaciones totales y genera el 19% del empleo a nivel nacional y el 66% en las zonas rurales. En el contexto del municipio de Sesquilé, la producción en el sector pecuario ha generado la inconformidad por parte de los habitantes y productores del municipio. Este trabajo de grado se desarrolla bajo la Metodología de Matriz de Marco Lógico, la cual presenta una dinámica de identificación del problema central que afecta al sector pecuario y permite plantear diferentes ejes para encontrar las alternativas más óptimas de mejoramiento al mismo, con el apoyo de la Alcaldía Municipal, los Presidentes de la Juntas de Acción Comunal y los habitantes. Para cumplir con el objetivo de caracterizar el sector pecuario del Municipio de Sesquilé, se tiene en cuenta variables productivas y logísticas, para la identificación de alternativas que permitan la generación de empleo y de ingresos en la población. Se identificaron problemas de carácter social, político, económico, tecnológico y logístico, a los cuales se establecen una serie de recomendaciones con pautas de cómo mejorar y aprovechar las oportunidades potenciales que brinda el sector.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Using monthly time-series data 1999-2013, the paper shows that markets for agricultural commodities provide a yardstick for real purchasing power, and thus a reference point for the real value of fiat currencies. The daily need for each adult to consume about 2800 food calories is universal; data from FAO food balance sheets confirm that the world basket of food consumed daily is non-volatile in comparison to the volatility of currency exchange rates, and so the replacement cost of food consumed provides a consistent indicator of economic value. Food commodities are storable for short periods, but ultimately perishable, and this exerts continual pressure for markets to clear in the short term; moreover, food calories can be obtained from a very large range of foodstuffs, and so most households are able to use arbitrage to select a near optimal weighting of quantities purchased. The paper proposes an original method to enable a standard of value to be established, definable in physical units on the basis of actual worldwide consumption of food goods, with an illustration of the method.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

In recent years the contribution of the marketing function has changed and interest now centres on its contribution to a firm’s financial performance. The Marketing Science Institute in the USA has stated that it is the number one marketing issue facing corporate America. The Australian Marketing Institute is promoting a set of marketing metrics that will help Australian firms measure the function’s contribution to shareholder value creation. Much of the literature relates notions such as customer satisfaction and other marketing activities with a firm’s profit. A missing link appears to be the choice firms make in terms of which customer groups to target and the resultant impact on shareholder value performance. The generic customer groups comprise: existing customers, former customers and prospects. A review of the literature reveals that marketing costs and benefits vary across these groups. The challenge for management is to determine which group represents the best target and to allocate scarce marketing resources accordingly. The task is made even more challenging because the economic value of members within each group also varies and some product lines may be unprofitable and therefore, may not be worth pursuing. To generate superior shareholder value it may not simply be the case of acquiring the maximum number of new customers from any source but to find the appropriate mix of the generic customer groups and manage the individual customer relationships accordingly. This paper seeks to firstly summarise and review the recent literature on marketing and its relationship to shareholder value and secondly to propose a model for allocating marketing resources across generic customer groups in order to generate improved shareholder value performance. Importantly, the model not only covers increasing business with customers but also shedding customers or shedding the extent of business conducted with customers as means of generating shareholder value.