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1.
《L'Anthropologie》2019,123(2):319-332
The territory of actual Kazakhstan is well known by a high concentration of archaeological sites of different phases of Palaeolithic period. This country situated at the crossroad of two worlds – between Europe and Asia – can be seen as one of the most important territories for understanding of the conduct of Prehistory not only in Central Asia, but also around of the world. The Prehistory study of Kazakhstan helps us to complete the image of the first human migrations from Africa. The lithic material from these sites is discovered in abundance. However, the most ancient period of Human civilisation of this territory is little known and studied not enough. By this paper we try to show the application of a new approach of the techno-typological study to the archaeological material to give a more exhaustive image of the lithic collections from the Palaeolithic sites of the Semizbugu complex and, based on the obtained data, to reconstruct the chain of lithic tools fabrication.  相似文献   

2.

The ability to measure bone tissue material properties plays a major role in diagnosis of diseases and material modeling. Bone’s response to loading is complex and shows a viscous contribution to stiffness, yield and failure. It is also ductile and damaging and exhibits plastic hardening until failure. When performing mechanical tests on bone tissue, these constitutive effects are difficult to quantify, as only their combination is visible in resulting stress–strain data. In this study, a methodology for the identification of stiffness, damping, yield stress and hardening coefficients of bone from a single cyclic tensile test is proposed. The method is based on a two-layer elasto-visco-plastic rheological model that is capable of reproducing the specimens’ pre- and postyield response. The model’s structure enables for capturing the viscously induced increase in stiffness, yield, and ultimate stress and for a direct computation of the loss tangent. Material parameters are obtained in an inverse approach by optimizing the model response to fit the experimental data. The proposed approach is demonstrated by identifying material properties of individual bone trabeculae that were tested under wet conditions. The mechanical tests were conducted according to an already published methodology for tensile experiments on single trabeculae. As a result, long-term and instantaneous Young’s moduli were obtained, which were on average 3.64 GPa and 5.61 GPa, respectively. The found yield stress of 16.89 MPa was lower than previous studies suggest, while the loss tangent of 0.04 is in good agreement. In general, the two-layer model was able to reproduce the cyclic mechanical test data of single trabeculae with an root-mean-square error of 2.91 ± 1.77 MPa. The results show that inverse rheological modeling can be of great advantage when multiple constitutive contributions shall be quantified based on a single mechanical measurement.

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4.
Aim, Scope and Background  Acquisition and analysis of huge amounts of data still pose a challenge, with few options available for solutions and support. Life cycle assessment (LCA) experts face such problems on a daily basis. However, data do not become useful until some of the information they carry is extracted, and most important, represented in a way humans can both recognize efficiently and understand and interpret as quickly as possible. Unfortunately, information representation techniques as used in this field are still based on traditional low-dimensional information spaces, featuring only a few basic choices to represent life cycle (LC) related data. We must part from those traditional techniques and shift to visual representations that are easier for us to understand due to the human capability for detecting spatial structures and shapes represented in different colors and textures. Then all the advantages of modern, advanced information visualization can be applied and exploited. Main Features  With the introduction of a new glyph-based information representation and visualization approach to LCA, current issues of representing LC-related information efficiently at a glance are being tackled. These new techniques support reduction of information load by providing tools to select and summarize data, assist in making explicit and transparent data feature propagation, and provide a means of representing data errors and uncertainty. In this approach the human perceptual capability for easily and quickly recognizing and understanding graphical objects in different colors and textures is exploited for the design and application of highly structured and advanced forms of multi-dimensional information representation. Results  Now in the example presented in this paper, OM-glyphs were used to represent LCA-related information for an industrial product and its compiled life cycle inventory under conditions normal for LCA. To demonstrate the application and benefits of the approach introduced, several different visualization scenarios were computed and presented. These were illustrated with a selection of generated glyph-based displays containing spherical glyph clusters for environmental items such as air pollutants and water pollutants, and inventory glyph matrices related to components and to LC phases. Where appropriate, to further aid understanding and clarity, displays were additionally shown with various orientations and in enlarged form. This is a functional feature of interactive 3D OM-glyph based information visualization that can be used in practice to efficiently navigate through displays while at the same time adjusting rendered scenes to the needs of the user at any given time. Due to the huge amount of data acquired and compiled, only a small fraction of the glyph-based displays could be shown, and, in consequence, only a fraction of the data properties, patterns and features available could be discussed in detail. However, it is believed that the basic principles and methods of this approach, as shown in a real application, could be clearly conveyed, and, most important, that the benefits and potential could be displayed in a convincing manner. This technology will support a marked increase in efficiency, speed and quality in LC information analysis. Conclusions  This paper concludes our short series on efficient information visualization in LCA. A new approach to efficient information visualization has been introduced, together with its basic principles. This background was enriched with discussions on and further insights into technical details of the approach and the framework developed. The first practical examples were provided in the previous paper, demonstrating the mapping of LCA-related data and their contexts to glyph parameters. In this paper the application of the approach was presented using data for an actual industrial product. During the discussions, and with the various glyph-based displays shown, it could be convincingly demonstrated that all data features, trends, patterns, relationships, and data imperfections detected and examined, and sometimes traced, could be quickly and efficiently recognized in a short time. Even basic data features, such as small gaps in the data propagation of related values, could be easily seen using OM-glyphs. In the case of traditional data representation, using for example LCI tables, this would require the identification and comparison of several thousand numerical entries. As is the case with all new technology, however, it is still difficult to obtain the interest of the experts, and to convince them that such new ideas will eventually change the face of industry. Outlook  A new, advanced and efficient information representation and visualization approach has been introduced to the LCA community. Hopefully, through this small series of papers, some interest will have been generated in the field of advanced information visualization. For the first time this area has been related to LCA, and some seeds for interdisciplinary research may have been sown. Now it is up to individuals, the experts in the various fields elated to those issues, to respond. The desired results will be stimulating discussions, an exchange of ideas, further initiated multilateral, interdisciplinary efforts, and improved collaboration between partners from academia and industry. At that point, efficient information visualization will finally have arrived at, and received, its deserved place within LCA.  相似文献   

5.
While many factors affecting human health that will alter with climate change are being discussed, there has been no discussion about how a warmer future will affect man’s thermoregulation. Using historical climate data for an Australian city and projections for Australia’s climate in 2070, we address the issue using heat balance modelling for humans engaged in various levels of activity from rest to manual labour. We first validate two heat balance models against empirical data and then use the models to predict the number of days at present and in 2070 that (1) sweating will be required to attain heat balance, (2) heat balance will not be possible and hyperthermia will develop, and (3) body temperature will increase by 2.5°C in less than 2 h, which we term “dangerous days”. The modelling is applied to people in an unacclimatised and an acclimatised state. The modelling shows that, for unacclimatised people, outdoor activity will not be possible on 33–45 days per year, compared to 4–6 days per year at present. For acclimatised people the situation is less dire but leisure activity like golf will be not be possible on 5–14 days per year compared to 1 day in 5 years at present, and manual labour will be dangerous to perform on 15–26 days per year compared to 1 day per year at present. It is obvious that climate change will have important consequences for leisure, economic activity, and health in Australia.  相似文献   

6.
Aim, Scope and Background  When materials are recycled they are made available for use for several future life cycles and can therefore replace virgin material more than just once. In order to analyse the optimal waste management system for a given material, the authors have analysed the material flows in a life cycle perspective. It is important to distinguish this approach for material flow analysis for a given material from life cycle analysis of products. A product life cycle analysis analyses the product system from cradle to grave, but uses some form of allocation in order to separate the life cycle of one product from another in cases where component materials are recycled. This paper does not address allocation of burdens between different product systems, but rather focuses on methodology for decision making for waste management systems where the optimal waste management system for a given material is analysed. The focus here is the flow of the given material from cradle (raw material extraction) to grave (the material, or its inherent energy, is no longer available for use). The limitation on the number of times materials can be recycled is set by either the recycling rate, or the technical properties of the recycled material. Main Features  This article describes a mathematical geometric progression approach that can be used to expand the system boundaries and allow for recycling a given number of times. Case studies for polyethylene and paperboard are used to illustrate the importance of including these aspects when part of the Goal and Scope for the LCA study is to identify which waste management treatment options are best for a given material. The results and discussion examine the different conclusions that can be reached about which waste management option is most environmentally beneficial when the higher burdens and benefits of recycling several times are taken into account. Results  In order to assess the complete picture of the burdens and benefits arising from recycling the system boundaries must be expanded to allow for recycling many times. A mathematical geometric progression approach manages to take into account the higher burdens and benefits arising from recycling several times. If one compares different waste management systems, e.g. energy recovery with recycling, without expanding the system to include the complete effects of material recycling one can reach a different conclusion about which waste management option is preferred. Conclusions  When the purpose of the study is to compare different waste management options, it is important that the system boundaries are expanded in order to include several recycling loops where this is a physical reality. The equations given in this article can be used to include these recycling loops. The error introduced by not expanding the system boundaries can be significant. This error can be large enough to change the conclusions of a comparative study, such that material recycling followed by incineration is a much better option than waste incineration directly. Recommendations and Outlook  When comparing waste management solutions, where material recycling is a feasible option, it is important to include the relevant number of recycling loops to ensure that the benefits of material recycling are not underestimated. The methodology presented in this article should be used in future comparative studies for strategic decision-making for waste management. The approach should not be used for LCAs for product systems without due care, as this could lead to double counting of the benefits of recycling (depending on the goal and scope of the analysis). For materials where the material cycle is more of a closed loop and one cannot truly say that recycled materials replace virgin materials, a more sophisticated approach will be required, taking into account the fact that recycled materials will only replace a certain proportion of virgin materials.  相似文献   

7.
Aim, Scope and Background  The data-intensive nature of life cycle assessment (LCA), even for non-complex products, quickly leads to the utilization of various methods of representing the data in forms other than written characters. Up until now, traditional representations of life cycle inventory (LCI) data and environmental impact analysis (EIA) results have usually been based on 2D and 3D variants of simple tables, bar charts, pie charts and x/y graphs. However, these representation methods do not sufficiently address aspects such as representation of life cycle inventory information at a glance, filtering out data while summarizing the filtered data (so as to reduce the information load), and representation of data errors and uncertainty. Main Features  This new information representation approach with its glyph-based visualization method addresses the specific problems outlined above, encountered when analyzing LCA and EIA related information. In particular, support for multi-dimensional information representation, reduction of information load, and explicit data feature propagation are provided on an interactive, computer-aided basis. Results  Three-dimensional, interactive geometric objects, so called OM-glyphs, were used in the visualization method introduced, to represent LCA-related information in a multi-dimensional information space. This representation is defined by control parameters, which in turn represent spatial, geometric and retinal properties of glyphs and glyph formations. All relevant analysis scenarios allowed and valid can be visualized. These consist of combinations of items for the material and energy inventories, environmental items, life cycle phases and products, or their parts and components. Individual visualization scenarios, once computed and rendered on a computer screen, can then interactively be modified in terms of visual viewpoint, size, spatial location and detail of data represented, as needed. This helps to increase speed, efficiency and quality of the assessment performance, while at the same time considerably reducing mental load due to the more structured manner in which information is represented to the human expert. Conclusions  The previous paper in this series discussed the motivation for a new approach to efficient information visualization in LCA and introduced the essential basic principles. This second paper offers more insight into and discussion on technical details and the framework developed. To provide a means for better understanding the visualization method presented, examples have been given. The main purpose of the examples, as already indicated, is to demonstrate and make transparent the mapping of LCA related data and their contexts to glyph parameters. Those glyph parameters, in turn, are used to generate a novel form of sophisticated information representation which is transparent, clear and compact, features which cannot be achieved with any traditional representation scheme. Outlook  Final technical details of this approach and its framework will be presented and discussed in the next paper. Theoretical and practical issues related to the application of this visualization method to the computed life cycle inventory data of an actual industrial product will also be discussed in this next paper.  相似文献   

8.

While there are a number of sleep medicine and sleep research publications in Asia, and their quality is increasing each year, the actual situation of sleep disorders in the general population still remains an issue of major concern. Scientists and medical doctors believe that, for the first time in history, the general lack of sleep could lead to a diminution of life expectancy. It is also known that, as people are working more and more and are more tired, they are more likely to become victims of accidents. Most of the time these incidents have little gravity, but sometimes they can cost thousands of innocent lives or contribute to disasters such as the Chernobyl nuclear plant explosion or the Bhopal gas tragedy. Based on the Asian Sleep Research Society Summit and Symposium Round Table held during the fall of 2009 on Okinawa, this review aims to give an accurate view of the actual situation of sleep research and medicine in Asia. The particular example of the obstructive sleep apnea syndrome will illustrate the importance of sleep medicine in this part of the world. Finally, the actual situation will be discussed to elaborate some possible strategies to improve the sleep situation for Asian populations.

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9.
Goal, Scope and Background  The EU 5th framework project OMNIITOX will develop models calculating characterisation factors for assessing the potential toxic impacts of chemicals within the framework of LCA. These models will become accessible through a web-based information system. The key objective of the OMNIITOX project is to increase the coverage of substances by such models. In order to reach this objective, simpler models which need less but available data, will have to be developed while maintaining scientific quality. Methods. Experience within the OMNIITOX project has taught that data availability and quality are crucial issues for calculating characterisation factors. Data availability determines whether calculating characterisation factors is possible at all, whereas data quality determines to what extent the resulting characterisation factors are reliable. Today, there is insufficient knowledge and/or resources to have high data availability as well as high data quality and high model quality at the same time. Results  The OMNIITOX project is developing two inter-related models in order to be able to provide LCA impact assessment characterisation factors for toxic releases for as broad a range of chemicals as possible: 1) A base model representing a state-of-the-art multimedia model and 2) a simple model derived from the base model using statistical tools. Discussion. A preliminary decision tree for using the OMNIITOX information system (IS) is presented. The decision tree aims to illustrate how the OMNIITOX IS can assist an LCA practitioner in finding or deriving characterisation factors for use in life cycle impact assessment of toxic releases. Conclusions and Outlook  Data availability and quality are crucial issues when calculating characterisation factors for the toxicity impact categories. The OMNIITOX project is developing a tiered model approach for this. It is foreseen that a first version of the base model will be ready in late summer of 2004, whereas a first version of the simple base model is expected a few months later.  相似文献   

10.
For the analysis of ultrahigh-dimensional data, the first step is often to perform screening and feature selection to effectively reduce the dimensionality while retaining all the active or relevant variables with high probability. For this, many methods have been developed under various frameworks but most of them only apply to complete data. In this paper, we consider an incomplete data situation, case II interval-censored failure time data, for which there seems to be no screening procedure. Basing on the idea of cumulative residual, a model-free or nonparametric method is developed and shown to have the sure independent screening property. In particular, the approach is shown to tend to rank the active variables above the inactive ones in terms of their association with the failure time of interest. A simulation study is conducted to demonstrate the usefulness of the proposed method and, in particular, indicates that it works well with general survival models and is capable of capturing the nonlinear covariates with interactions. Also the approach is applied to a childhood cancer survivor study that motivated this investigation.  相似文献   

11.
Goal, Scope and Background This paper gives an overview on how the wood and packaging material production is inventoried in ecoinvent. Packaging materials have been a very important topic in the area of Life Cycle Assessment for more than twenty years. Wood is the most important renewable material and regenerative fuel used worldwide, and an important raw material for paper / board. Several methodological problems arising when inventorying wood for material and energetic uses in a generic database are discussed in more detail. Within the ecoinvent project, the Swiss data base for life cycle inventory data, two reports are dedicated to these two important topics – report No. 9 for wood and report No. 11 for packaging materials. Methods The whole wood chain has been modeled in a consistent way. This allows one to use this data for LCAs of building materials, bioenergy or paper production. The data represent average technologies used in Central Europe in the year 2000. A revenue-based co-product allocation approach is used for the different outputs. Correction factors are introduced for the consistent modeling of mass-based, material inherent wood properties such as solar energy, carbon uptake and land use. For packaging materials, the datasets represent European average data for the most often used materials as well as specific datasets for the production of actual packaging boxes and containers.Results and Discussion For wood, revenue-based allocation and the use of the correction factors for mass-related wood properties are shown and explained. For packaging materials, the importance of the raw material wood to the total load is shown. Furthermore trends in the data inventories for board packaging materials over the last two decades are discussed: mainly due to the increased comprehensiveness of the data, higher cumulative emissions can be observed. Conclusion For wood, the database ecoinvent provides consistent datasets for the entire chain from forestry to intermediate products such as timber, different types of wood-based boards, chips, pellets, etc. For packaging materials, the number of datasets of basic materials has been extended. A modular concept for actual packaging container datasets allows the user an easy modeling of various types of packaging containers/boxes. In the area of paper and board, a comprehensive database for the production of various types of pulp, paper and board is provided, which is representative for the average European production situation. Outlook Since wood is only limited and representative data for Europe is therefore not included, an update in the near future would be reasonable. Possible further extensions in the future could include various, final wooden products. For the data on paper/board, different levels of quality are observed, requiring a selective up-date of these data. Future extensions could include datasets for the import of pulp from overseas – especially from South America and Canada.  相似文献   

12.

Background  

One of the most powerful methods for the prediction of protein structure from sequence information alone is the iterative construction of profile-type models. Because profiles are built from sequence alignments, the sequences included in the alignment and the method used to align them will be important to the sensitivity of the resulting profile. The inclusion of highly diverse sequences will presumably produce a more powerful profile, but distantly related sequences can be difficult to align accurately using only sequence information. Therefore, it would be expected that the use of protein structure alignments to improve the selection and alignment of diverse sequence homologs might yield improved profiles. However, the actual utility of such an approach has remained unclear.  相似文献   

13.
Aim, Scope and background  Given the communication limitation of a damage-oriented approach, the question addressed in this paper is how normalisation can be developed instead. Normalisation of product service systems without value choices is, in accordance to ISO 14042, suitable for external communication. Reason normalisation approaches use a geographically-defined baseline year of emissions, optionally combined with politically established target emissions (Guinée 2002, Stranddorf et al. 2001). In contradiction to these approaches, this paper aims to draw up the general structure of an alternative normalisation procedure. The normalisation procedure suggested here is based on environmental quality objectives (EQO), in order to streamline the result to include as few output parameters as possible, without compromising the scientific robustness of the method. Main Features  This article describes a normalisation procedure based on environmental quality objectives. Comparison between this approach and a damage-oriented approach is conducted. The relevant working area concerning dose and effect is evaluated. Then a discussion is conducted focusing on the trade-off necessary to achieve an integrated category indicator, covering the following issues; model reliability, user applicability and the unambiguously of the result. Result  A damage-oriented approach will have to take into account all the defined consequences from all impact categories that affect the safeguards in parallel. In other words, each impact category indicator and its potential effects on all safeguards must be evaluated and accounted for. In the case where a single category indicator cannot be found without utilising value choices, a number of category indicators will then have to constitute an intermediate category indicator result, where weighting must be applied in order to streamline the result. In contrast to the above approach, the suggested normalisation procedure utilises the precautionary principle with respect to the essential EQO in order to achieve a category indicator result, called a critical load category indicator result. In practice, this means that the number of figures in an LCIA-profile based on critical load will always be the same as the number of impact categories. Conclusions  The suggested EQO normalisation procedure forms a set of critical loads per impact category, where each is defined by a critical load function where linearity is defined between a zero load and the critical load. This procedure will affect the temporal resolution and the field of application of the LCIA method. The positive aspect is that the suggested normalisation procedure renders the method applicable for long-lived products like, for example, buildings or other infrastructures. This aspect is gained by reducing the damage-oriented resolution. Consequently, for long-lived products where the main environmental loads will appear in the future, it is hard to assess by a damage-oriented LCIA method (if all boundary conditions are not assumed to be fixed). The EQO normalisation method will, in this respect, improve the overall reliability of the outcome of an LCA when long-lived products are assessed. For short-lived products, adequate boundary conditions can be achieved, and for this reason a damage-oriented approach will have the possibility to address current consequences. Nevertheless, a damage-oriented approach working area is not applicable beneath thresholds unlike the EQO normalisation procedure. The most effective decision support of short-lived products is therefore achieved when both approaches are applied. Outlook  A complementary paper will be produced where the described normalisation procedure is exemplified in a case study, with special interest on assessment of chemical substances.  相似文献   

14.
Background, aim, and scope  Under ISO 14040, normalisation is an optional step in life-cycle impact assessment designed to provide environmental context by indicating the relative contribution that the product system under investigation makes in the various impact categories, in comparison to a suitable reference scenario. The challenge for many studies, however, is to provide the appropriate context by adopting a normalisation reference scenario that is well matched to the product system’s parent environment. Australia has a highly urbanised population, mainly contained in just eight capital cities. In the context of normalising environmental impacts against the profile of an ‘average’ Australian, this poses a unique problem, compared to other industrialised regions of the world. This study aims to use publicly available data on environmentally relevant emissions and non-renewable resource consumption in 2005/2006 to develop regional normalisation data for Australia, at both inventory and characterisation levels. Methods  The regionalised inventory of emissions and resources production is constructed using a framework of 60 regional Statistical Divisions from the Australian Standard Geographical Classification system. Data from the National Pollutant Inventory, Australian Greenhouse Emissions Information System and the Australian Bureau of Agricultural and Resource Economics (energy and mineral statistics) are used as the basis for the inventories. These data could subsequently be used by any LCA practitioner to construct characterisation or normalisation data by impact category, according to any preferred life-cycle impact assessment methodology, for any of 60 regions in the country. In this study, the regionalised inventory data were assessed using the CML 2001 baseline and IMPACT 2002+ life-cycle impact assessment methods in SimaPro v.7.1.5. Results  Characterisation results from the two LCIA methods for Australia’s eight state and territory capital cities are presented, together with an overall national profile. These data are also shown on a per capita basis to highlight the relative environmental profiles of citizens in the different cities. Interestingly, many significant impacts occur outside of the capital cities but are linked to facilities providing the majority of their services and products to these urban centres (e.g. power stations, minerals processing). Comparison of the average Australian data with the Netherlands, Western Europe and the World shows the results to be broadly similar. Discussion  Analysis of the CML 2001 baseline characterisation results, on a per capita basis, shows substantial differences between the major cities of the country. In each impact category, these differences can be successfully traced to specific emissions in the raw data sources, the influence of prevailing climate conditions, or factors such as the mix of non-renewable energy resources in each state. Some weaknesses are also evident in the collection and estimation techniques of the raw data sources and in the application of European-based impact assessment models. Australia is a net exporter of many products, particularly natural resources. Therefore, a significant part of the characterisation data presented here for Australia represents products that will be consumed in other parts of the world. Similarly, at a regional level, there will be many inventory items produced in one area yet consumed in another. In this way, the impacts associated with consumption (particularly in densely populated but largely industry-free cities) are dissipated into other production centres. Conclusions  This study provides the first set of comprehensive inventory and characterisation data for Australia from a production perspective, disaggregated at a regional level. Despite Australia’s unique spatial demography, it is now possible to properly characterise the relative significance of environmental impacts occurring in any of 60 specific regions across the country. Recommendations and perspectives  Australia’s unique concentration of urban populations demonstrates the importance of regionally specific environmental assessments. Whilst the data presented in this study will be of most use to Australian LCA practitioners, it is also demonstrative of the broader global distribution of environmental impacts between urban and non-urban areas. The disconnection of environmental impacts between the place of production and the place of consumption is highlighted by this study and should be considered in any studies using these normalisation data for environmental profiling. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   

15.
In many randomized clinical trials of therapeutics for COVID-19, the primary outcome is an ordinal categorical variable, and interest focuses on the odds ratio (OR; active agent vs control) under the assumption of a proportional odds model. Although at the final analysis the outcome will be determined for all subjects, at an interim analysis, the status of some participants may not yet be determined, for example, because ascertainment of the outcome may not be possible until some prespecified follow-up time. Accordingly, the outcome from these subjects can be viewed as censored. A valid interim analysis can be based on data only from those subjects with full follow-up; however, this approach is inefficient, as it does not exploit additional information that may be available on those for whom the outcome is not yet available at the time of the interim analysis. Appealing to the theory of semiparametrics, we propose an estimator for the OR in a proportional odds model with censored, time-lagged categorical outcome that incorporates additional baseline and time-dependent covariate information and demonstrate that it can result in considerable gains in efficiency relative to simpler approaches. A byproduct of the approach is a covariate-adjusted estimator for the OR based on the full data that would be available at a final analysis.  相似文献   

16.
17.
Attributional and consequential LCA of milk production   总被引:1,自引:1,他引:0  
Background, aim and scope  Different ways of performing a life cycle assessment (LCA) are used to assess the environmental burden of milk production. A strong connection exists between the choice between attributional LCA (ALCA) and consequential LCA (CLCA) and the choice of how to handle co-products. Insight is needed in the effect of choice on results of environmental analyses of agricultural products, such as milk. The main goal of this study was to demonstrate and compare ALCA and CLCA of an average conventional milk production system in The Netherlands. Materials and methods  ALCA describes the pollution and resource flows within a chosen system attributed to the delivery of a specified amount of the functional unit. CLCA estimates how pollution and resource flows within a system change in response to a change in output of the functional unit. For an average Dutch conventional milk production system, an ALCA (mass and economic allocation) and a CLCA (system expansion) were performed. Impact categories included in the analyses were: land use, energy use, climate change, acidification and eutrophication. The comparison was based on four criteria: hotspot identification, comprehensibility, quality and availability of data. Results  Total environmental burdens were lower when using CLCA compared with ALCA. Major hotspots for the different impact categories when using CLCA and ALCA were similar, but other hotspots differed in contributions, order and type. As experienced by the authors, ALCA and use of co-product allocation are difficult to comprehend for a consequential practitioner, while CLCA and system expansion are difficult to comprehend for an attributional practitioner. Literature shows concentrates used within ALCA will be more understandable for a feeding expert than the feed used within CLCA. Outcomes of CLCA are more sensitive to uncertainties compared with ALCA, due to the inclusion of market prospects. The amount of data required within CLCA is similar compared with ALCA. Discussion  The main cause of these differences between ALCA and CLCA is the fact that different systems are modelled. The goal of the study or the research question to be answered defines the system under study. In general, the goal of CLCA is to assess environmental consequences of a change in demand, whereas the goal of ALCA is to assess the environmental burden of a product, assuming a status-quo situation. Nowadays, however, most LCA practitioners chose one methodology independent of their research question. Conclusions  This study showed it is possible to perform both ALCA (mass and economic allocation) and CLCA (system expansion) of milk. Choices of methodology, however, resulted in differences in: total quantitative outcomes, hotspots, degree of understanding and quality. Recommendations and perspectives  We recommend LCA practitioners to better distinguish between ALCA and CLCA in applied studies to reach a higher degree of transparency. Furthermore, we recommend LCA practitioners of different research areas to perform similar case studies to address differences between ALCA and CLCA of the specific products as the outcomes might differ from our study.  相似文献   

18.
A large and increasing number of women in the western world will at some point during their life be investigated morphologically for breast cancer. Fine needle aspiration (FNA) is one morphological method which is considered to be the fastest, cheapest and the most patient-friendly approach. Nevertheless, the technique has not gained major clinical success outside of Scandinavia, mainly because of a high frequency of insufficient samples. With this in mind it is quite peculiar that standard needles which are mainly configured for blood sampling and infusion therapy, comprising large quantities of residual spaces, are used. In this study we have developed and tested a new needle dedicated for FNA, which is intended to abate this drawback by increasing the sampling yield by changing the tip angle, the cannula wall-thickness and the storage compartment. In total, 499 consecutive aspiration procedures of palpable breast lesions were performed to compare the new needle (outer diameter 0.6 mm) with standard needles (outer diameters 0.6 mm and 0.7 mm). The new needle provided three times more material than did standard needles of the same diameter. Surprisingly, the new needle also provided more material than the standard 0.7 mm needle, which increased up to almost twice the material in cases with no material in the syringe. The frequency of tests with sparse harvested material (<4 mg) was less with the new needle (9%) compared to its standard counterpart (35%). The presented results were obtained by a very skilled sampling operator. Thus for the average sampling operator who probably obtains more samples in the spare range, the new dedicated FNA needle should have even more added value.  相似文献   

19.
Critical conservation decisions often hinge on estimates of population size, population growth rate, and survival rates, but as a practical matter it is difficult to obtain enough data to provide precise estimates. Here we discuss Bayesian methods for simultaneously drawing on the information content from multiple sorts of data to get as much precision as possible for the estimates. The basic idea is that an underlying population model can connect the various sorts of observations, so this can be elaborated into a joint likelihood function for joint estimation of the respective parameters. The potential for improved estimates derives from the potentially greater effective sample size of the aggregate of data, even though some of the data types may only bear directly on a subset of the parameters. The achieved improvement depends on specifics of the interactions among parameters in the underlying model, and on the actual content of the data. Assuming the respective data sets are unbiased, notwithstanding the fact that they may be noisy, we may gauge the average improvement in the estimates of the parameters of interest from the reduction, if any, in the standard deviations of their posterior marginal distributions. Prospective designs may be evaluated from analysis of simulated data. Here this approach is illustrated with an assessment of the potential value in various ways of merging mark-resight and carcass-survey data for the Florida manatee, as could be made possible by various modifications in the data collection protocols in both programs.  相似文献   

20.
The saiga (Saiga tatarica, Bovidae, Cetartiodactyla) is facing a precarious situation in the wild and unfortunately also zoos have failed so far in establishing a stable captive population. Cologne Zoo was one of the most successful zoos in holding and breeding this endangered species. We analysed life history and breeding of the Cologne animals. We highlight differences between wild and captive saigas and potential trouble spots for captive breeding. Being seasonal breeders, oestrus length usually lasted 1–2 days with an average time of 19.85 days between oestrus periods if not pregnant. Gestation lengths lasted 133–151 days with gestations of twins 4.39 days shorter on average than for one lamb. Bearing twins was not a rule for the Cologne saigas. We found correlations between litter size and the age of the female or the number of births of the female, respectively. A disparity between the theoretically possible number of offspring and the actual number born emphasises the need to safeguard continuous breeding, to prevent the loss of the few years in a female’s breeding life. The information that emerged from our study will be valuable if future captive breeding of saigas is intended.  相似文献   

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