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41.
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Wulf-Peter?SchmidtEmail author 《The International Journal of Life Cycle Assessment》2003,8(3):167-174
Background In developing products various requirements have to be integrated including functionality, quality, affordability as well
as environmental aspects. Often conflicting requirements have to be fulfilled. Therefore, multi-dimensional decision support
approaches are necessary.
Methods Here, one approach is to relate the conflicting requirements to each other. Life Cycle Costing (LCC) has the potential to
support the trade-off between some environmental targets and overall affordability targets by including all monetary flows
along the product life cycle (going beyond the well-known costs of ownership by integrating also long-term use and end-of-life
costs). Those solutions can be identified that (a) have the highest efficiencies (where do we get most environmental improvements
per Ϊ and (b) have the highest affordability for the customer along the life cycle. Furthermore, on-costs in the design phase
can be justified in terms of future savings either for the customer or for the recycling of the products. These represent
real business cases for environmental actions. Three types of environmental business cases can be differentiated.
Results and Discussion This paper presents various examples where LCC is integrated into product design. However, there are a number of open issues
in the implementation of LCC within real product development including data availability and uncertainty (future costs/ savings),
level of discounting, accounting and compensation. Various internal case studies done in the last years showed that already
few changes in the costs structure can significantly affect the identi-fied future costs.
Recommendation and Outlook Uncertainties in LCC are higher than in LCA and highest when applied in the stage of product develop-ment, i.e. used to support
DfE action. As a consequence, the result-ing figures can only be seen as directional. Therefore, the use of LCC in Design
for Environment cannot be recommended without major restrictions in terms of guidance, experience/training. The link-age between
LCC and DfE can either be established via (1) experts supporting design teams or (2) as part of a DfE tool. The DfE tool has
to include detailed guidance for interpretation, and its application should be based on a solid training for DfE engineers. 相似文献
43.
LCA of concrete and steel building frames 总被引:1,自引:0,他引:1
Asa Jonsson Thomas Bjorklund Anne -Marie Tillman 《The International Journal of Life Cycle Assessment》1998,3(4):216-224
The effects on the external environment of seven concrete and steel building frames representative of present-day building
technology in Sweden were analysed using LCA methodology. Objects of the study included frame construction and supplementary
materials. Several-storey offices and dwellings were studied. The functional unit was defined as one average m2 of floor area during the lifetime of the building. Inventory data were elaborated for concrete and steel production, the
building site, service life, demolition and final disposal. Parameters included were raw material use, energy use, emissions
to air, emissions to water and waste generation. The inventory results were presented and evaluated as such, in addition to
an interpretation by using three quantitative impact assessment methods. Parameters that weighed heavily were use of fossil
fuels, CO2, electricity, SOx
2 NOx
2 alloy materials and waste, depending on what assessment method was used. Over the life cycle, building production from cradle
to gate accounted for about the same contribution to total environmental loads as maintenance and replacement of heat losses
through external walls during service life, whereas demolition and final disposal accounted for a considerably lower contribution. 相似文献
44.
Post‐market monitoring (PMM) consistent with Swiss and European Union legislation should ensure the detection and prevention of adverse effects on the environment possibly deriving from commercial cultivation of genetically modified (GM) crops. Insect‐resistant GM crops (such as Bt‐maize) raise particular questions regarding disturbances of biological control functions provided by beneficial insects such as predators and parasitoids (so‐called natural enemies). Consensus among regulators, scientists and the agricultural biotech industry on appropriate PMM plans allowing the detection and possibly prevention of such adverse effects is still lacking. The aims of this study were to identify the necessity for PMM of Bt‐maize expressing Cry1Ab on natural enemies and to develop an appropriate PMM plan. The approach chosen consisted in determining what type of monitoring is most appropriate to address potential effects of Bt‐maize on natural enemies during commercial cultivation. This included identifying whether there remain substantial scientific uncertainties that would support case‐specific monitoring. Existing pre‐market risk assessment data indicate that Bt‐maize (Cry1Ab) comprises a negligible risk for disturbances in biological control functions of natural enemies. As a consequence, a faunistic monitoring of specific groups of natural enemies is not considered an appropriate approach to detect failures in biological control functions. Alternatively, an approach is proposed that consists in indirectly analysing biological control functions by surveying outbreaks of maize herbivores. Unusual herbivore outbreaks could indicate failures in biological control functions of natural enemies. Data could be collected via questionnaires addressed to farmers growing Bt‐maize. Significant correlations between unusual occurrences of specific maize herbivores and the cultivation of Bt‐maize would subsequently need specific studies to determine possible causalities in more detail. The here proposed approach has the advantage of covering different natural enemy groups. It represents a cost‐effective strategy to obtain scientifically sound data as a basis for regulatory decision‐making. 相似文献
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49.
Yang Ou Shang-Jui Wang Le Jiang Bin Zheng Wei Gu 《The Journal of biological chemistry》2015,290(1):457-466
Although p53 is frequently mutated in human cancers, about 80% of human melanomas retain wild-type p53. Here we report that PHGDH, the key metabolic enzyme that catalyzes the rate-limiting step of the serine biosynthesis pathway, is a target of p53 in human melanoma cells. p53 suppresses PHGDH expression and inhibits de novo serine biosynthesis. Notably, upon serine starvation, p53-mediated cell death is enhanced dramatically in response to Nutlin-3 treatment. Moreover, PHGDH has been found recently to be amplified frequently in human melanomas. We found that PHGDH overexpression significantly suppresses the apoptotic response, whereas RNAi-mediated knockdown of endogenous PHGDH promotes apoptosis under the same treatment. These results demonstrate an important role of p53 in regulating the serine biosynthesis pathway through suppressing PHGDH expression and reveal serine deprivation as a novel approach to sensitize p53-mediated apoptotic responses in human melanoma cells. 相似文献
50.
Alteration of tubuliform silk gland cytoarchitecture with the reproductive cycle of the Western black widow spider,Latrodectus hesperus 下载免费PDF全文
Elizabeth Herrera Ly Truc Nguyen Erica Escobar Wendy Ouriel Merri Lynn Casem 《Invertebrate Biology》2015,134(4):332-340
The protein synthetic and secretory activity of spider tubuliform glands is known to be coordinated with the reproductive stage of the spider. For spiders that produce multiple egg cases, such as the black widow Latrodectus hesperus, this means that the cells that make up the tubuliform gland cycle from minimal to maximal silk protein synthesis and exocytosis as the spider transitions from early vitellogenesis to a gravid state and back. The impact of these transitions on the cells that form the tubuliform gland has yet to be characterized. The entire tubuliform gland undergoes an elastic deformation, doubling in size in response to the accumulation and depletion of egg case silk proteins within its lumen. Similarly, the diversity and organization of organelles within the cytoplasm of the secretory epithelial cells that make up the wall of the tubuliform gland change with the reproductive stage of the spider. Progression of a spider from early to late vitellogenesis is accompanied by decondensed nucleoli and distention of the rough endoplasmic reticulum, markers of protein synthetic activity. The presumed silk proteins that fill the lumen of the tubuliform gland of a gravid spider include a fibrous matrix with homogeneous spherical inclusions. These components are also present within the cytoplasm of the cell; however, only the fibrous material appears to be enclosed by membranous organelles. Transition of the tubuliform gland from peak silk synthesis back to a quiescent state is marked by the appearance of multivesicular bodies and organelles resembling phagophores and autophagosomes, suggestive of a role for autophagy in the process of recovery. The reproducible cellular dynamics of the tubuliform silk gland of the black widow spider makes it a potential model system for study of the regulation of silk gene expression, endomembrane transport, and exocytosis of silk proteins and autophagy. 相似文献