脂肪干细胞在组织工程中的研究进展

随着组织工程技术的不断发展,种子细胞的来源问题已经成为制约其发展的一个重要的因素,,自脂肪间充质干细胞发现以来,人们对其的研究不断深入。近几年,越来越多的实验证实,脂肪间充质干细胞可以向成骨细胞、成软骨细胞、神经细胞、肌细胞和脂肪细胞等不同胚层来源的细胞分化。而且脂肪组织来源广泛、取材容易、便于自体移植：脂肪间充质干细胞在体外长期培养的过程中始终保持其多向分化潜能、遗传背景相当稳定、体内植入后少有免疫排斥的问题,因而是一种非常理想的组织工程种子细胞。     

Carbon and energy prices under uncertainty: A theoretical analysis of fuel switching with heterogenous power plants

European power producers have a major influence on the EU ETS, given that both their CO₂ emissions and their EUA (European Union Allowance) allocations account for more than half of the total volumes of the scheme. Fuel switching is often considered as the main short-term abatement measure under the EU ETS. It consists in substituting combined cycle gas turbines (CCGTs) for hard-coal plants in power generation. Thereby coal plants run for shorter periods, and CO₂ emissions are reduced. This paper provides the first theoretical analysis of fuel switching, in a context where power plants involved are not equally efficient. We begin with a preliminary work using illustrative examples and sensitivity analyses, which enables us to observe how differences in the efficiency of power plants impact the cost of fuel switching, and how this is related to the level of switching effort. Based on this, we build a theoretical model taking into account the effect of differences in the efficiency of power plants involved in fuel switching. We also investigate the effect of the timing of fuel switching abatements, within the temporally defined environment of our dynamic model. Results demonstrate that the gas price and uncontrolled CO₂ emissions act together on the carbon price. We show that the influence of the gas price on the carbon price depends on the level of uncontrolled CO₂ emissions, due to heterogeneity of power plants that are used in the fuel switching process. Furthermore, we show that the time of occurrence of uncontrolled emissions matters so that shocks have a stronger impact when they occur in a period that is closed to the end of the phase.     

A choice experiment on fuel taxation and earmarking in Norway

Pigouvian taxes are efficient — but unpopular among voters — and hence often politically infeasible. Earmarking of revenues has been widely reported to increase public support for taxes, but earmarking is generally not the most efficient use of the revenues. This trade-off between efficiency and political feasibility is the motivation for our primary research objective: to quantify the effect of earmarking on support for fuel tax rises. Our secondary research objective is to investigate why earmarking increases support. Using data from a representative sample of the Norwegian voter population (N = 1147), we estimate models of voter preferences for fuel taxes using logistic regression models. Our results show that, in the absence of earmarking, the majority of voters would like to reduce fuel taxes, but earmarking the revenues for environmental measures has a substantial effect on voter support for fuel tax increases, garnering a majority for increases of up to 15% above present levels. Further analysis indicates that a prime reason why earmarking for environmental measures is popular is that it increases the perceived environmental effectiveness of the tax, and hence its legitimacy as an environmental rather than a fiscal policy instrument.     

Identifying R&D partners through Subject-Action-Object semantic analysis in a problem & solution pattern

Today’s companies still rely heavily on expert knowledge rather than quantitative data with a systematic approach to effectively identify and choose Research and Development (R&D) partners. It is advantageous to identify and select potential R&D partners using a Problem & Solution (P&S) pattern. This paper presents a novel process for identifying R&D partners on the basis of solution similarities that assist technology managers in understanding the relationships between research targets. First, we choose a thematic dataset that contains problems and quantitative data with relative topic terms. Then, we extract Subject-Action-Object semantic structures in a P&S pattern from the dataset, and identify various solutions to a technical problem, with each as a subject. In addition, we provide correlation mapping to visualise the text characters and identify R&D partners. Finally, we validate the proposed method through a case study of the dye-sensitized solar cells sector.     

Should I advertise on the interstate?

The highway logo signing program has existed for over 20 years. Since its inception, most motorists have become accustomed to relying on these blue signs to provide information on services available at each highway exit. However, there is little, if any, literature that examines the program as an advertising source, and no formal literature that addresses the signing program from the perspective of the independent business owner. This paper provides service business owners with information about the highway logo signing program, and is directed toward independent owners who are considering the signing program as an advertising source. A five step process is described that owners can follow to first determine if the venue is viable, and then if the investment is value-added for them.     

燃油税实施效果评价及税制完善的建议

我国燃油税改革正式实施已满两年,其积极的效果和存在的弊端初步显现。本文在对我国燃油税改善的实施效果进行评价的基础上,借鉴典型国家燃油税税制的设立经验,提出完善我国燃油税税制的建议。     

THE CHOICE OF CELLS IN CHI–SQUARE TESTS

The choice of cells in chi–square goodness of fit tests is a classical problem. Some recent results in this area are discussed. It is shown that the likelihood ratio of alternatives w.r.t. null distributions plays a key role when judging different procedures. The discussion centers on the case of a simple hypothesis, but location–scale models and tests of independence in contingency tables are also considered.     

On the power of indicators: how the choice of fuel poverty indicator affects the identification of the target population

In light of the creation of the EU Energy Poverty Observatory (EPOV) in January 2018 and the increase in debates on how fuel poverty is measured, we propose a critical analysis of fuel poverty indicators and demonstrate that choosing a given indicator is central to the identification of the fuel-poorpopulation.

First, we conducted an inter-indicator analysis to show how profiles of fuel-poor households vary depending on the indicator selected. We designed a multidimensional approach based on a multiple correspondence analysis and a hierarchical and partitioning clustering analysis to study characteristics of fuel-poor households. We highlight the difficulty of identifying a fuel-poor ‘typical profile’ and show that the composition of the population depends on the choice of the indicator.

Second, we applied an intra-indicator analysis using two objective expenditure-based indicators with thresholds. In particular, we conducted a sensitivity analysis based on a logit model including variables describing household and dwelling characteristics. We show that the profiles of fuel-poor households as well as the drivers of fuel poverty vary considerably with the chosen threshold level.Given these findings, we stress the need to review how we currently rely on conventional fuel poverty indicators to identify target groups and give some recommendations.     

浅析电子喷油器常用的检测方法

气车电控汽油喷射系统已经成为汽油车的标准配置。文章介绍了电子喷油器的常见故障、产生的原因及检测方法。     

燃油税政策的国际比较与启示

世界各国征收的燃油税大多是以消费税和增值税为主的多个税种的组合。尽管各国燃油税有差异,但也有许多共性,如燃油课税的主要目的都是作为道路交通建设资金的来源;燃油税多是采取从量定额征收,税费占燃油价格的比例都较高;车用燃料消费所占比例越高的油品,征收环节越靠近生产环节;对非道路用燃料进行税收减免等。本文认为,开征燃油税首要目的是筹集道路养护资金,其次才是促进节能与环保,应综合考虑各种因素来设置税率,并辅之以相应的税收优惠措施。