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1.

Purpose

Product category rules (PCRs) provide category-specific guidance for estimating and reporting product life cycle environmental impacts, typically in the form of environmental product declarations and product carbon footprints. Lack of global harmonization between PCRs or sector guidance documents has led to the development of duplicate PCRs for the same products. Differences in the general requirements (e.g., product category definition, reporting format) and LCA methodology (e.g., system boundaries, inventory analysis, allocation rules, etc.) diminish the comparability of product claims.

Methods

A comparison template was developed to compare PCRs from different global program operators. The goal was to identify the differences between duplicate PCRs from a broad selection of product categories and propose a path toward alignment. We looked at five different product categories: milk/dairy (two PCRs), horticultural products (three PCRs), wood?Cparticleboard (two PCRs), and laundry detergents (four PCRs).

Results and discussion

Disparity between PCRs ranged from broad differences in scope, system boundaries, and impacts addressed (e.g., multi-impact vs. carbon footprint only) to specific differences of technical elements. The differences primarily reflected the different purposes of the PCR (e.g., label/report), the different standards they were based on (e.g., ISO 14025/PAS 2050), the use of different product categorization systems, or simply the result of being developed independently. Differing degrees of specificity and terminology between PCRs allowed for varied interpretation??at times making direct comparison difficult. For many of the differences between PCRs, however, there was no clear rationale why they could not be consistent in the future.

Conclusions

These results were used to outline a general guidance document for global alignment of PCRs which recommends (1) alignment of PCRs for different purposes, (2) provision of guidance for the adoption of aspects of other PCRs, and (3) provision of greater specificity on content. The overall recommendations also suggest collaboration among program operators to facilitate alignment on issues that evolve from independent development.  相似文献   

2.
3.

Purpose

The growing phase of emerging economy countries requires the implementation of environmental assessment tools in the building sector. The use of environmental product declarations (EPDs) has risen in developed countries as one of the main tools for environmental assessment. However, at what point should developing countries follow the EPD implementation strategies used by developed countries? What are the strengths and weaknesses of EPD in the emerging economy context, and what threats and opportunities does it face within the building sector? This work aims to answer these questions by taking Mexico as a case study.

Methods

A bibliographical review was conducted to determine the key elements for EPD development in the building sector in other countries, especially those in Europe, where EPDs originated. The review also examined the experience and perspective of other countries that are starting to contemplate this type of ecolabel as an option for environmental assessment within their own building sectors, as well as industry perspectives on EPDs, especially those of small and medium-sized enterprises (SMEs). Then, Mexico’s situation in regard to these key elements was examined, with a special focus on the main stakeholders detected: government and industry. Finally, after a contrast analysis was conducted between the developed countries and Mexico, the strengths and weaknesses of EPDs in the emerging economy context and the threats and opportunities within the building sector were determined.

Results and discussion

The use of EPDs in Europe has largely followed a normative and legislative pattern. Moreover, it has been the main data source for building environmental assessment schemes, and there is a strong life cycle assessment (LCA) platform that contributes to EPD development. Furthermore, there is a European tendency toward making the use of EPDs mandatory. However, there is a very different reality in emergent economy countries. In these countries, social housing represents a major part of the vision of the building sector, so it is taken as an initial approach to EPD development. In Mexico, there is a solid legislative framework in which EPDs could be implemented, and there is a variety of environmental assessment housing programs into which EPDs could be integrated. Nevertheless, there is an institutional void that has prevented the incorporation of the life cycle approach into the national strategy of sustainability in the building sector. Moreover, SMEs might not have the technical and financial capacity to develop EPD.

Conclusions

This analysis has proved that EPD implementation in emerging countries mainly depends on two aspects: Firstly, it must be a shared vision of sustainability between government and industry, in which there is a correspondence between the sustainability objectives of the two parties and SMEs have the ability to contribute toward their achievement. Secondly, a solid platform of knowledge that supports LCA in the building sector is necessary, and it must involve a strong relationship between government, academia, and stakeholders.
  相似文献   

4.

Purpose

The development of product category rules (PCRs) is inconsistent among the program operators using ISO 14025 as the basis. Furthermore, the existence of several other product claim standards and specifications that require analogous rules for making product claims has the potential to reduce any consistency in PCRs present in the ISO 14025 domain and result in unnecessary duplication of PCRs. These inconsistencies and duplications can be attributed to (a) insufficient specificity in related standards, (b) the presence of several standards and specifications, (c) lack of/limited coordination among program operators, and (d) lack of a single global database for PCRs. As a result, current PCR development threatens the legitimacy of life cycle assessment-based product claims.

Process

Through discussions over the past few years, in multistakeholder organizations, it has become clear that more guidance on the development of PCRs is necessary. In response to this need, the Product Category Rule Guidance Development Initiative (www.pcrguidance.org) was launched as an independent multistakeholder effort in early 2012. The premise for the Initiative was that the Guidance would be created by a voluntary group of international stakeholders that would share ownership of the outputs.

Outcome

The Guidance is now published, along with supplementary materials, on the Initiative website. The guidance document specifies requirements, recommendations, and options on (1) steps to be taken before PCR creation; (2) elements of a PCR; (3) review, publication, and use of PCRs; and (4) best practices for PCR development and management. Supplementary materials include a PCR template, a conformity assessment form, and a list of program operators from around the world.

Conclusions

The Guidance will help reduce cost and time to develop a PCR by supporting the adaptation of an existing PCR or by building on elements from existing PCRs. It will help reduce confusion and frustration when creating PCRs that are based on one or more standards and programs. Overall, the Guidance is a robust handbook for consistency and clarity in the development of PCRs.  相似文献   

5.

Introduction

The European Commission is supporting the development of the International Reference Life Cycle Data System (ILCD). This consists primarily of the ILCD Handbook and the ILCD Data Network. This paper gives an insight into the scientific positions of business, governments, consultants, academics, and others that were expressed at this public consultation workshop.

Workshop focus

The workshop focused on four of the topics of the main guidance documents of the ILCD Handbook: (1) general guidance on life cycle assessment (LCA); (2) guidance for generic and average life cycle inventory (LCI) data sets; (3) requirements for environmental impact assessment methods, models and indicators for LCA; and (4) review schemes for LCA.

Workshop participation

This consultation workshop was attended by more than 120 participants during the 4 days of the workshop. Representatives came from 23 countries, from both within and outside the European Union.

Workshop structure

Approximately half of the participants were from business associations or individual companies. Another 20% were governmental representatives. Others came predominantly from consultancies and academia.

Results

This public consultation workshop provided valuable inputs into the overall ILCD Handbook developments as well as for further development. This paper focuses on some of the main scientific issues that were raised.  相似文献   

6.

Purpose

Porcelain stoneware tile (PST) is currently the ceramic tile of greatest commercial and innovation interest. An environmental life cycle assessment of different varieties of PST was undertaken to enable hotspots to be identified, strategies to be defined, differences between PST varieties to be evaluated and guidance for PST manufacturers to be provided in choosing the Environmental Product Declaration (EPD) programme that best suited their needs according to grouping criteria.

Methods

Analysis of previous information allowed three main parameters (thickness, glaze content and mechanical treatment) to be identified in order to encompass all PST variations. Fifteen varieties of PST were thus studied. The coverage of 1 m2 of household floor surface with the different PST varieties for 50 years was defined as functional unit. The study sets out environmental data whose traceability was verified by independent third parties for obtaining 14 EPDs of PST under Spanish EPD programmes.

Results and discussion

The study presents PST inventory analysis and environmental impact over the entire life cycle of the studied PST varieties. The natural gas consumed in the manufacturing stage accounted for more than 70% abiotic depletion–fossil fuels and global warming; electricity consumption accounted for more than 60% ozone layer depletion, while the electricity generated by the cogeneration systems avoided significant environmental impacts in the Spanish power grid mix. The variations in PST thickness, amount of glaze and mechanical treatments were evaluated. The PST variety with the lowest environmental impact was the one with the lowest thickness, was unglazed and had no mechanical treatments. Similarly, the PST variety with the highest environmental impact was the one with the greatest thickness, was glazed and had been mechanically treated.

Conclusions

The PST life cycle stage with the highest environmental impact was the manufacturing stage. The main hotspots found were production and consumption of energy and raw materials extraction. Variation in thickness was a key factor that proportionally influenced almost all studied impact categories; the quantity of glaze strongly modified abiotic depletion–elements and eutrophication, while the mechanical treatments contributed mainly to ozone depletion. The study of all PST varieties led to the important conclusion, against the current trend, that differences among them were found to be so significant that declaring a number of PSTs within the same EPD is not directly possible, and it needs preliminary verification to ensure compliance with the product category rule.
  相似文献   

7.

Purpose

Growing public concern about the current state of our planet led to the creation of numerous regulations, standards, and certifications for the protection of humans and the environment. Ecolabels were defined for products such as cleaning products, paints, and many others. Wood building products are no exception. The objective of this study is to analyze the existing ecolabelling programs for appearance wood products in nonresidential applications and to evaluate them relatively to their effective role in environment protection or reduction of environment footprint.

Methods

The research was conducted on the most common International Organization for Standardization (ISO) type I ecolabels in North America, the European Union, and Japan. Certification schemes applicable to appearance wood products for nonresidential applications were considered. In a life cycle assessment perspective, certification criteria were compared regarding their ability to consider and integrate environment impacts.

Results and discussion

A wide range of ecolabels can apply to appearance wood products, from indoor air quality to wood from sustainable forest management. Moreover, it has been found that among all certification schemes studied, those integrating the whole life cycle were the most relevant.

Conclusions

The remaining limitation of ISO type I ecolabels is the lack of environmental information enabling the differentiation between products bearing the same ecolabel. This can be overcome by ISO type III environmental product declarations. Thus, allowing a better understanding of the implications related with the use of wood products compared to other materials in the nonresidential building sector.  相似文献   

8.

Goal, Scope and Background

The aim of the present study is to evaluate, through LCA, the potential environmental impact associated to urban waste dumping in a sanitary landfill for four case studies and to compare different technologies for waste treatment and leachate or biogas management in the framework of the EPD® system. Specific data were collected on the four Italian landfills during a five-year campaign from 2000 to 2004. This work also analyses the comparability of EPD results for different products in the same product category. For this purpose, a critical review of PSR 2003:3, for preparing an EPD on ‘Collection, transfer and disposal service for urban waste in sanitary landfills', is performed.

Methods

PSR 2003:3 defines the requirements, based on environmental parameters, that should be considered in an LCA study for collecting and disposal service of Municipal Solid Waste (MSW) in a sanitary landfill. It defines functional unit, system boundaries towards nature, other technical systems and boundaries in time, cut-off rules, allocation rules and parameters to be declared in the EPD. This PSR is tested on four case studies representing the major landfills located from the farthest west to the farthest east side of the Ligurian Region. Those landfills are managed with different technologies as concerns waste pre-treatment and leachate or biogas treatment. For each landfill, a life cycle assessment study is performed.

Results and Discussion

The comparison of the LCA results is performed separately for the following phases: Transport, Landfill, Leachate and Biogas. The following parameters are considered: Resource use (Use of non-renewable resources with and without energy content, Use of renewable resources with and without energy content, Water consumption); Pollutant emissions expressed as potential environmental impact (Global Warming Potential from biological and fossil sources, Acidification, Ozone depletion, Photochemical oxidant formation, Eutrophication, Land use, Hazardous and other Waste production). The comparison of the LCA results obtained for alternative landfill and biogas management techniques in the case studies investigated shows that the best practicable option that benefits the environment as a whole must be identified and chosen in the LCA context. For example, a strong waste pre-treatment causes a high biological GWP in the Landfill phase, but a low GWP contribution in the Biogas phase, due to the consequent low biogas production, evaluated for 30 years since landfill closure.

Conclusion

The analysis of four case studies showed that, through the EPD tool, it is possible to make a comparison among different declarations for the same product category only with some modification and integration to existent PSR 2003:3. Results showed that different products have different performances for phases and impact categories. It is not possible to identify the \best product\ from an environmental point of view, but it is possible to identify the product (or service) with the lowest impact on the environment for each impact category and resource use.

Recommendation and Perspective

In consequences of the verification of the comprehensiveness of existent PSR 2003:3 for the comparability of EPD, some modifications and integration to existent rules are suggested.
  相似文献   

9.

Purpose

Life cycle assessment (LCA) is a tool that can be utilized to holistically evaluate novel trends in the construction industry and the associated environmental impacts. Green labels are awarded by several organizations based on single or multiple attributes. The use of multi-criteria labels is a good start to the labeling process as opposed to single criteria labels that ignore a majority of impacts from products. Life cycle thinking, in theory, has the potential to improve the environmental impacts of labeling systems. However, LCA databases currently are lacking in detailed information about products or sometimes provide conflicting information.

Method

This study compares generic and green-labeled carpets, paints, and linoleum flooring using the Building for Environmental and Economic Sustainability (BEES) LCA database. The results from these comparisons are not intuitive and are contradictory in several impact categories with respect to the greenness of the product. Other data sources such as environmental product declarations and ecoinvent are also compared with the BEES data to compare the results and display the disparity in the databases.

Results

This study shows that partial LCAs focused on the production and transportation phase help in identifying improvements in the product itself and improving the manufacturing process but the results are uncertain and dependent upon the source or database. Inconsistencies in the data and missing categories add to the ambiguity in LCA results.

Conclusions

While life cycle thinking in concept can improve the green labeling systems available, LCA data is lacking. Therefore, LCA data and tools need to improve to support and enable market trends.  相似文献   

10.

Purpose

In this study, life cycle assessment (LCA) is applied to a sample of 40 low-energy individual houses for the French context in order to identify guidance values for different environmental priorities (energy and water consumption, greenhouse gases emissions, waste generation etc.).

Methods

Calculation rules for the LCA derived from EeBGuide guidance and HQE Performance specific rules for the French context. Data are based on Environmental Product Declaration (EPD for the impacts related to products and technical equipment while generic data are used for energy and water processes. The LCA is defined for the entire life cycle of a building from cradle-to-grave according to NF EN 15978 standard. It includes the products and equipment implemented in the building, the different uses of energy for heating, domestic hot water, lighting, ventilation and auxiliaries, and the different uses of water consumption.

Results and discussion

Results for the 40 houses showed that the average life cycle non-renewable primary energy consumption is about 37 kWh/(m2*year) while the life cycle greenhouse gases emissions are of 8.4 kg CO2-eq/(m2*year). The embodied impacts represent between 40% and 72% for the following indicators: acidification, global warming, non-renewable primary energy, and radioactive waste. The net fresh water use is mostly determined by the direct use of the water in use, and the non-hazardous waste indicator is only linked to the materials and equipment. When integrating the variability of the different houses design, energy performance, climate requirements, it was found that those values can vary of an order of two between the 10 and 90% percentiles’ values. It was found that the results are also sensitive to the enlargement of the system boundaries (e.g. inclusion of the other uses of energy such as building appliances) and the modification of the reference study period.

Conclusions and recommendations

This study provided a first set of LCA guidance values describing a range of environmental impacts for new low-energy individual houses in France. Results were also reported for different design parameters, system boundaries and reference study period. The outcomes of this study can now serve as a basis to guide and support new LCA-based labelling systems developed by public authorities and labelling schemes (e.g. the HQE Association).
  相似文献   

11.

Purpose

The paper provides a late report from the United Nations Environment Program (UNEP)/Society of Environmental Toxicology and Chemistry (SETAC) Life Cycle Initiative workshop “Life Cycle Impact Assessment (LCIA)—where we are, trends, and next steps;” it embeds this report into recent development with regard to the envisaged development of global guidance on environmental life cycle impact assessment indicators and related methodologies.

Methods

The document is the output of the UNEP/SETAC Life Cycle Initiative’s workshop on “Life Cycle Impact Assessment—where we are, trends, and next steps.” The presentations and discussions held during the workshop reviewed the first two phases of the Life Cycle Initiative and provided an overview of current LCIA activities being conducted by the Initiative, governments and academia, as well as corporate approaches. The outcomes of the workshop are reflected in light of the implementation of the strategy for Phase 3 of the Life Cycle Initiative.

Results

The range of views provided during the workshop indicated different user needs, with regards to, amongst other things, the required complexity of the LCIA methodology, associated costs, and the selection of LCIA categories depending on environmental priorities. The workshop’s results signified a number of potential focus areas for Phase 3 of the Initiative, including capacity building efforts concerning LCIA in developing countries and emerging economies, the preparation of training materials on LCIA, the production of global guidance on LCIA, and the potential development of a broader sustainability indicators framework.

Conclusions

These suggestions have been taken into account in the strategy for Phase 3 of the Life Cycle Initiative in two flagship projects, one on global capability development on life cycle approaches and the other on global guidance on environmental life cycle impact assessment indicators. In the context of the latter project, first activities are being organized and planned. Moreover, UNEP has included the recommendations in its Rio + 20 Voluntary Commitments: UNEP and SETAC through the UNEP/SETAC Life Cycle Initiative commit to facilitate improved access to good quality life cycle data and databases as well as expanded use of key environmental indicators that allows the measurement and monitoring of progress towards the environmental sustainability of selected product chains.  相似文献   

12.

Purpose

The objective of the paper is to discuss the role of a new guidance document for life cycle assessment (LCA) in the construction sector available as an online InfoHub.

Methods

This InfoHub derives from the EeBGuide European project that aimed at developing a guidance document for energy-efficient building LCA studies. The InfoHub is built on reference documents such as the ISO 14040-44 standards, the EN 15804 and EN 15978 standards as well as the ILCD Handbook. The guidance document was filled with expertise and knowledge of several experts. The focus was put on providing scientifically sound, yet practical guidance.

Results

The EeBGuide InfoHub is an online guidance document, setting rules for conducting LCA studies and giving instructions on how to do this. The document has a section on buildings—new and existing—and a section on construction products. It is structured according to the life cycle stages of the European standards EN 15804 and EN 15978, covering all aspects of LCA studies by applying provisions from these standards and the ILCD handbook, wherever applicable. The guidance is presented for different scopes of studies by means of three study types. For the same system boundaries, default values are proposed in early or quick assessment (screening and simplified LCA) while detailed calculation rules correspond to a complete LCA. Such approach is intended to better match the user needs in the building sector.

Conclusions and recommendations

This paper can be viewed as a contribution to the ongoing efforts to improve the consistency and harmonisation in LCA studies for building products and buildings. Further contributions are now needed to improve building LCA guidance and to strengthen links between research, standardisation and implementation of LCA in the construction practice.  相似文献   

13.

Purpose

A strategic product development tool combining REACH and environmental and financial factors was previously developed for a coatings company. This paper presents results from refining this tool for an office furniture company, using life cycle assessment (LCA)-based environmental information, addressing the research questions: ? Is it possible to combine information from REACH with the LCA approach to provide useful information for a furniture producer in their environmental product development process? ? Does the approach developed for substances in mixtures need to be adapted for articles? ? Is there a correlation between energy consumption and the environmental impacts analysed? ? Will product designers get the same information independent of the environmental impact category used? ?C Will the strategy tool indicate the same ranking of products for all environmental impacts? ?C Does REACH information indicate the same set of priorities as those arising from LCA environmental data alone? (Do they agree, or is there a conflict?) ? Will strategic decisions differ if different environmental indicators are in focus? The strategy tool??s purpose is to analyse company product portfolios, identifying products that need redevelopment or redesign because of issues concerning hazardous substances, or environmental performance.

Methods

The LCA data used is cradle-to-gate data from type III environmental declarations for 11 seating solutions. REACH Complexity, health hazard and environmental class indicators (based on risk phrases) are combined with financial data and LCA-based indicators. Correlations between energy consumption and environmental impact factors for these specific furniture products are investigated. Establishing any such correlations serves to simplify subsequent analysis in the product development process, by effectively reducing the number of indicators that need to be taken into consideration.

Results

Correlations between energy consumption and the environmental impacts global warming, acidification, eutrophication and heavy metals are presented. Strategy tool figures are shown for energy consumption, ozone depletion potential and photochemical oxidation potential. The results for office chairs and conference/visitor chairs are presented separately, as the two types of chairs fulfil different functions.

Conclusions

The correlation between energy consumption and certain environmental impact indicators affords a simplification of the product development process, since energy consumption can be used as a reasonable proxy for these indicators in this specific case. The results support acknowledged principles of Ecodesign. Energy and materials minimization improves environmental performance??higher recycled material content and proportion of renewable energy resources are also beneficial. Designers have to consider multiple aspects in parallel and the strategy tool is useful for this purpose; the furniture producer has gained useful product development insight. The tool is applicable for strategic choice of products for development or redesign that can be useful across many business sectors.  相似文献   

14.

Background

The design of oligonucleotides and PCR primers for studying large genomes is complicated by the redundancy of sequences. The eukaryotic genomes are particularly difficult to study due to abundant repeats. The speed of most existing primer evaluation programs is not sufficient for large-scale experiments.

Results

In order to improve the efficiency and success rate of automatic primer/oligo design, we created a novel method which allows rapid masking of repeats in large sequence files, for example in eukaryotic genomes. It also allows the detection of all alternative binding sites of PCR primers and the prediction of PCR products. The new method was implemented in a collection of efficient programs, the GENOMEMASKER package. The performance of the programs was compared to other similar programs. We also modified the PRIMER3 program, to be able to design primers from lowercase-masked sequences.

Conclusion

The GENOMEMASKER package is able to mask the entire human genome for non-unique primers within 6 hours and find locations of all binding sites for 10 000 designed primer pairs within 10 minutes. Additionally, it predicts all alternative PCR products from large genomes for given primer pairs.  相似文献   

15.

Purpose

The number of scrap tires generated in China has grown dramatically every year. Generation of ground rubber from scrap tires is the dominant management option in China. It is necessary to assess the environmental impacts of ground rubber production from scrap tires to provide technical advices on a cleaner production.

Methods

Production of ground rubber from recycled scrap tires consist of three steps: rubber powder preparation, devulcanization, and refining. A process life cycle assessment (LCA) of ground rubber production from scrap tires is carried out, and Eco-indicator 99 method coupled with ecoinvent database is applied to evaluate the environmental impacts of this process.

Results and discussion

During the ground rubber production stage, the impact factor of respiratory inorganic is the most serious one. Devulcanization has the highest environmental load of about 66.2 %. Moreover, improvement on the flue gas treatment contributes to a cleaner production and a more environmental-friendly process. Applying clean energy can largely reduce environmental load by about 21.5 %.

Conclusions

The results can be a guidance to reduce environmental load when producing ground rubber from scrap tires. Meanwhile, increasing energy efficiency, improving environmental protection equipment, and applying clean energy are the effective measures to achieve this goal.  相似文献   

16.

Purpose

The paper introduces the publication on “Global Guidance Principles for Life Cycle Assessment Databases”; it focuses on the development of training material and other implementation activities on the publication.

Methods

The document is the output of the “Shonan Guidance Principles” workshop. The publication provides guidance principles for life cycle assessment (LCA) databases; this includes how to collect raw data, how to develop datasets, and how to manage databases. The publication also addresses questions concerning data documentation and review, coordination among databases, capacity building, and future scenarios. As a next step, the publication is used to prepare training material and other implementation activities.

Results

The publication was launched at the LCM 2011 Conference. Since then outreach activities have been organized in particular in emerging economies. Further developments with regard to the guidance principles are foreseen as part of a flagship project within phase 3 of the Life Cycle Initiative. Training material is being developed that will include how to set up databases and develop datasets. The topic has been taken up by United Nations Environment Programme (UNEP) in its Rio?+?20 Voluntary Commitments: UNEP and Society of Environmental Toxicology and Chemistry (SETAC) through the UNEP/SETAC Life Cycle Initiative commit to facilitate improved access to good quality life cycle data and databases as well as expanded use of key environmental indicators that allows the measurement and monitoring of progress towards the environmental sustainability of selected product chains.

Conclusions

The adoption of the “Global Guidance Principles” publication as a de facto global standard is expected to facilitate the work of database teams, especially, in developing countries, and the collaboration in regional networks. These efforts are supported by the development of training material and other implementation activities.  相似文献   

17.

Key message

The rice local population was clearly differentiated into six groups over the 100-year history of rice breeding programs in the northern limit of rice cultivation over the world.

Abstract

Genetic improvements in plant breeding programs in local regions have led to the development of new cultivars with specific agronomic traits under environmental conditions and generated the unique genetic structures of local populations. Understanding historical changes in genome structures and phenotypic characteristics within local populations may be useful for identifying profitable genes and/or genetic resources and the creation of new gene combinations in plant breeding programs. In the present study, historical changes were elucidated in genome structures and phenotypic characteristics during 100-year rice breeding programs in Hokkaido, the northern limit of rice cultivation in the world. We selected 63 rice cultivars to represent the historical diversity of this local population from landraces to the current breeding lines. The results of the phylogenetic analysis demonstrated that these cultivars clearly differentiated into six groups over the history of rice breeding programs. Significant differences among these groups were detected in five of the seven traits, indicating that the differentiation of the Hokkaido rice population into these groups was correlated with these phenotypic changes. These results demonstrated that breeding practices in Hokkaido have created new genetic structures for adaptability to specific environmental conditions and breeding objectives. They also provide a new strategy for rice breeding programs in which such unique genes in local populations in the world can explore the genetic potentials of the local populations.  相似文献   

18.

Introduction

Percutaneous or endocavitory drainage of a diverticular abscess under radiological guidance often enables one to perform a one-staged resection and anastomosis (without stoma formation) instead of a two-staged procedure. It reduces the significant postoperative morbidity and mortality associated with the conventional emergency surgical management. However, radiological guidance is not always available due to limited resources during out-of-hours.

Case presentation

A 78-year-old Caucasian woman underwent transrectal drainage of a diverticular abscess performed with a pigtail catheter without radiological guidance. Technical details of the procedure are described and alternative options discussed.

Conclusion

In carefully selected patients, per-rectal drainage using a pigtail catheter can be performed without radiological guidance and the procedure offers a simple and effective way of controlling sepsis.  相似文献   

19.

Purpose

Disposable beverage bottles made of polyethylene terephthalate (PET) stand in sharp contrast to many other disposable plastic packaging systems in the US for their high level of post-consumer recovery for recycling. This is due in part to container deposit programs in several US states, such as the California Redemption Value (CRV) program. We investigate the impacts of PET bottle recycling in the CRV program to evaluate its effectiveness at reducing environmental burdens.

Methods

We develop a life cycle model using standard process LCA techniques. We use the US LCI database to describe the energy production infrastructure and the production of primary materials. We describe the inventory and logistical requirements for materials recovery on the basis of state-maintained statistics and interviews with operators and industry representatives. We report inventory indicators describing energy, freight, and waste disposal requirements. We report several impact indicators based on CML and TRACI-2.0 techniques. We apply system expansion to compare post-consumer activities to produce secondary polymer against equivalent primary production.

Results and discussion

While bottle collection is distributed across the state, processing is more centralized and occurs primarily near urban centers. The average distance traveled by a bottle from discard to recovery is 145–175 km. Recycling requires 0.45–0.66 MJ of primary energy/L of beverage, versus 3.96 MJ during the pre-consumer phase. Post-consumer environmental impacts are significantly lower than pre-consumer impacts, with the exception of eutrophication. The results are robust to model sensitivity, with allocation of fuel for bottle collection being the most significant parameter. Curbside collection is slightly more energy efficient than consumer drop-off, and is subject to smaller parametric uncertainty. Recycling has the potential for net environmental benefits in five of seven impact categories, the exceptions being smog (marginal benefits) and eutrophication (increased impacts).

Conclusions

California’s decentralized program for collecting and processing PET bottles has produced a system which generates a large stream of post-consumer material with minimal environmental impact. The selection of a reclamation locale is the most significant factor influencing post-consumer impacts. If secondary PET displaces primary material, several environmental burdens can be reduced.

Recommendations and perspectives

Our results suggest that deposit programs on disposable packaging are an effective policy mechanism to increase material recovery and reduce environmental burdens. Deposit programs for other packaging systems should be considered.  相似文献   

20.

Background and aims

Rare Earth Elements (REE) are widely used to trace natural geochemical processes. They are also increasingly used by man (electronics industry, medicine, agriculture) and therefore considered as emerging pollutants. The present study documents REE mobility in non-polluted natural soil-plant systems in order to characterize their environmental availability for future anthropogenic pollution.

Methods

The study is based on a field approach in non-polluted natural sites with contrasting geological environments (limestone, granite, and carbonatite) and highly variable REE contents.

Results

REE concentrations in soils do not directly reflect bedrock concentrations, but depend largely on pedogenetic processes and on the mineralogy of bedrock and soil. The soils of all sites are with respect to bedrock enriched in heavy REE. The REE uptake by plants is not primarily controlled by the plant itself, but depends on the concentration and the speciation in the soil and the adsorbed soil water pool.

Conclusions

REE uptake by plant roots are linked with those of Fe. Roots absorb preferentially the light REE. Before translocation, REE are retained by the Casparian strip leading to much lower concentrations in the aerial parts. The transport of the REE within the xylem is associated with the general nutrient flux.  相似文献   

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