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1.
Approaches to semi-synthetic minimal cells: a review 总被引:1,自引:0,他引:1
Following is a synthetic review on the minimal living cell, defined as an artificial or a semi-artificial cell having the
minimal and sufficient number of components to be considered alive. We describe concepts and experiments based on these constructions,
and we point out that an operational definition of minimal cell does not define a single species, but rather a broad family
of interrelated cell-like structures. The relevance of these researches, considering that the minimal cell should also correspond
to the early simple cell in the origin of life and early evolution, is also explained. In addition, we present detailed data
in relation to minimal genome, with observations cited by several authors who agree on setting the theoretical full-fledged
minimal genome to a figure between 200 and 300 genes. However, further theoretical assumptions may significantly reduce this
number (i.e. by eliminating ribosomal proteins and by limiting DNA and RNA polymerases to only a few, less specific molecular
species). Generally, the experimental approach to minimal cells consists in utilizing liposomes as cell models and in filling
them with genes/enzymes corresponding to minimal cellular functions. To date, a few research groups have successfully induced
the expression of single proteins, such as the green fluorescence protein, inside liposomes. Here, different approaches are
described and compared. Present constructs are still rather far from the minimal cell, and experimental as well as theoretical
difficulties opposing further reduction of complexity are discussed. While most of these minimal cell constructions may represent
relatively poor imitations of a modern full-fledged cell, further studies will begin precisely from these constructs. In conclusion,
we give a brief outline of the next possible steps on the road map to the minimal cell.
相似文献
Pier Luigi Luisi (Corresponding author)Email: |
Francesca FerriEmail: |
Pasquale StanoEmail: |
2.
Greenhouse gas mitigation in developing countries through technology transfer?: a survey of empirical evidence 总被引:1,自引:0,他引:1
Sonja Peterson 《Mitigation and Adaptation Strategies for Global Change》2008,13(3):283-305
While greenhouse gas (GHG) emissions are projected to rise primarily in the developing countries, the potential for developing
new GHG mitigation technologies exists primarily in the industrialized countries. It is thus important, not only for predictions
about future emission paths but also for climate change mitigation policies, to understand how the international diffusion
of such technologies takes place and how it affects the energy infrastructure and GHG emissions in developing countries. This
paper provides an overview of the channels through which these technologies diffuse and focuses on the empirical evidence
pertaining to the effects these technologies have on GHG emissions in developing countries.
相似文献
Sonja PetersonEmail: |
3.
Recent paleogeographic scenarios postulate the isolation of continental Africa during the Late Cretaceous. The absence of abelisaurid theropods from Upper Cretaceous African strata was offered as support of hypothesized African isolation with the acknowledgement that the paucity of African abelisaurids may be mostly an issue of sampling. Here we report on a shed theropod tooth from the Upper Cretaceous (Maastrichtian, ∼70 Ma) Duwi Formation of Egypt. The tooth was referred to the Malagasy abelisaurid “Megalosaurus” crenatissimus (=Majungasaurus crenatissimus) in 1921. A discriminant function analysis was run to test for morphological congruence between the Egyptian tooth and the dentitions of 24 theropod taxa. The analysis correctly classified 96.6% of the teeth in the sample and assigned the tooth to Majungasaurus. As current paleogeographic reconstructions posit Madagascar had attained its current position relative to Africa before the Late Cretaceous, it is unlikely that the Egyptian tooth actually pertains to Majungasaurus. Nevertheless, its classification as an abelisaurid supports its referral to the clade. This tooth thus constitutes defensible evidence of an abelisaurid from the post-Cenomanian Cretaceous of mainland Africa. Combined with recent discoveries of abelisaurids in Niger and Morocco, the result indicates that Abelisauridae was a diverse group in Africa during the Cretaceous, existing in multiple places for at least ∼25 Ma and weakens support for hypotheses of an isolated Africa during the Late Cretaceous.Electronic Supplementary Material Supplementary material is available for this article at
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Joshua B. Smith (Corresponding author)Email: Phone: +1-314-9357033Fax: +1-314-9357361 |
Matthew C. LamannaEmail: |
4.
Earliest zygodactyl bird feet: evidence from Early Cretaceous roadrunner-like tracks 总被引:2,自引:2,他引:0
Fossil footprints are important in understanding Cretaceous avian diversity because they constitute evidence of paleodiversity
and paleoecology that is not always apparent from skeletal remains. Early Cretaceous bird tracks have demonstrated the existence
of wading birds in East Asia, but some pedal morphotypes, such as zygodactyly, common in modern and earlier Cenozoic birds
(Neornithes) were unknown in the Cretaceous. We, herein, discuss the implications of a recently reported, Early Cretaceous
(120–110 million years old) trackway of a large, zygodactyl bird from China that predates skeletal evidence of this foot morphology
by at least 50 million years and includes the only known fossil zygodactyl footprints. The tracks demonstrate the existence
of a Cretaceous bird not currently represented in the body fossil record that occupied a roadrunner (Geococcyx)-like niche, indicating a previously unknown degree of Cretaceous avian morphological and behavioral diversity that presaged
later Cenozoic patterns.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
相似文献
Masaki MatsukawaEmail: |
5.
G. J. Nabuurs I. J. J. van den Wyngaert W. Daamen H. Kramer P. Kuikman 《Mitigation and Adaptation Strategies for Global Change》2008,13(3):267-282
A full account for carbon dioxide (CO2) and other greenhouse gas balance is presented for the Dutch forest and nature areas for 1990–2002 at a Tier 2.5 level. The
paper outlines how complex guidelines can be turned into a practical system, appropriate for a small country, making use of
the best knowledge and data available. The net total sink of all processes of the forest and other nature terrains balance
is very stable through time around an average of 1.74 million tonnes of CO2 per year. The sink is to a large extent determined by the growth of forest remaining forest, and the harvest taking place
in there. Newly added processes in this new National System are significant as well, but they compensate each other. The sources
from deforestation and nitrous oxide (N2O) emissions (around 900 ktonne CO2) are for two thirds compensated by the sinks from afforestation, dead wood, soil C changes due to land use changes, and trees
outside the forest. The land use changes between 1990 and 2000 showed that The Netherlands has an annual deforestation of
2504 ha (0.7% of the forest area) and an afforestation of 3124 ha. Deforestation led in total over the 13 years of 1990–2002
to an emission of 11.2 million tonne CO2 compensated by only 1.9 million tonne CO2 due to afforestation.
相似文献
G. J. NabuursEmail: |
6.
Pablo del Río 《Mitigation and Adaptation Strategies for Global Change》2009,14(3):203-213
Internal mitigation projects have recently been proposed as an additional flexibility mechanism, particularly in the context
of the European Union. Their main objective is to engage sectors not included in the European Union emissions trading scheme
(EU ETS) in cost-effective emissions reductions. However, in this paper it is argued that, when assessed in terms of dynamic
efficiency, the instrument is likely to be, at best, irrelevant to induce the scale of systemic technological changes which
are required to tackle the climate change problem and, at worst, detrimental for this task. Insights from the Evolutionary
Economics of technological change complemented with political economy considerations are used to support this claim.
相似文献
Pablo del RíoEmail: |
7.
Shimpei Iwasaki Bam Haja Nirina Razafindrabe Rajib Shaw 《Mitigation and Adaptation Strategies for Global Change》2009,14(4):339-355
Climate change combined with human activities poses significant risks to people’s livelihood especially in developing countries.
Adaptation at the community level is of crucial importance in enabling them to respond to the direct and indirect effects
of changes in climate. In a case study of fishing communities in Chilika lagoon, India, the focus is made on understanding
climate change adaptation at the community level and scaling it up into the policy perspective through application of Sustainable
Livelihood Approach. This article challenges the research and policy community to encourage the identification of locally
negative constraints and positive strengths toward climate resilient communities in rural areas.
相似文献
Rajib ShawEmail: |
8.
Molecular topology is an application of graph theory and statistics in fields like chemistry, biology, and pharmacology, in
which the molecular structure matters. Its scope is the topological characterization of molecules by means of numerical invariants,
called topological indices, which are the main ingredients of the molecular topological models. These are statistical models
that are instrumental in the discovery of new applications of naturally occurring molecules, as well as in the design of synthetic
molecules with specific chemical, biological, or pharmacological properties. In this review, we focus on pharmacology, which
is a novel field of application of molecular topology. Besides summarizing some recent developments, we also seek to bring
closer this interesting biomedical application of mathematics to an interdisciplinary readership.
相似文献
Vincent M. VillarEmail: |
9.
Over the past decade “bicellar” lipid mixtures composed of the long-chain dimyristoyl phosphatidylcholine (DMPC) and the short-chain
dihexanoyl PC (DHPC) molecules have emerged as a powerful medium for studying membrane associated, biologically relevant macromolecules
and assemblies. Depending on temperature, lipid concentration and composition these lipid mixtures can assume a variety of
morphologies, some of them alignable in the presence of a magnetic field. This article will examine the biophysical studies
that have elucidated the various morphologies assumed by these lipid mixtures, and their use in the biochemical studies of
biomolecules.
相似文献
John KatsarasEmail: |
10.
N. Anger B. Brouns J. Onigkeit 《Mitigation and Adaptation Strategies for Global Change》2009,14(5):379-398
We investigate the role of domestic allowance allocation and global emissions constraints for the carbon-market impacts of
linking the EU Emissions Trading Scheme (ETS) internationally. Employing a quantitative simulation model of the global carbon
market, we find that the economic benefits from connecting the European ETS to emerging non-EU schemes strongly depend on
the regional allowance allocation of the linking participants: In a world of moderate carbon constraints, an economically
efficient regional allowance allocation induces a much stronger fall in total compliance costs than a sub-optimal (i.e. too
high) domestic allocation of emissions permits. However, a more efficient (i.e. stricter) allocation shifts abatement efforts
and compliance costs to energy-intensive industries which are covered by the domestic ETS. We further find that committing
to ambitious global emissions reduction targets (compatible with stabilizing CO2 concentrations at 450 ppm) induces much stronger regional abatement efforts and substantially higher compliance costs for
the abating regions. In such an ambitious climate policy regime, an efficient domestic allocation of allowances is even more
important from an economic perspective: Here, linking emissions trading schemes diminishes the associated compliance costs
on the largest scale.
相似文献
J. OnigkeitEmail: |
11.
Preety M. Bhandari Suruchi Bhadwal Ulka Kelkar 《Mitigation and Adaptation Strategies for Global Change》2007,12(5):919-933
India occupies 2.4% of the world’s geographical area with a large percentage of its land under agriculture. About 228 Million
hectares (Mha) of its geographical area (nearly 69%) fall within the dryland (arid, semi-arid and dry sub-humid) region. Of
the total cultivated area of 142 Mha, major part of agriculture in the country is rainfed, extending to over 97 Mha and constituting
nearly 68% of the net cultivated area, therefore making the agricultural sector vulnerable and exposed to the vagaries of
weather conditions. Climate change adds to this dimension of stress. A strong need is felt for targeting programmes in these
areas that address issues related to employing suitable soil and water conservation measures. In this context this paper seeks
to examine the case for watershed development as an adaptive strategy. An examination of the possibility of fortifying the
existing programme with a view to adapting to expected changes in climate in future is undertaken. Also, the possibility of
watershed development integrating into a suitable mitigation strategy for the country is assessed.
相似文献
Preety M. BhandariEmail: |
12.
Maisch MW Matzke AT Grossmann F Stöhr H Pfretzschner HU Sun G 《Die Naturwissenschaften》2005,92(1):40-44
A lower molar of a haramiyoid mammal is described from the Toutunhe Formation of Liuhuanggou near Urumqi in the southern Junggar Basin, Xinjiang, China. It is referred to Eleutherodon sp., otherwise exclusively known from the Upper Bathonian of England. It is the first record of the order Haramiyida from Asia and the first Mesozoic mammal described from the southern Junggar Basin. Apart from the English specimens of Eleutherodon and Staffia from the Upper Jurassic of East Africa, it is the geologically youngest haramiyoid known. It is the first vertebrate taxon from the Toutunhe Formation that is probably not endemic and lends some support to the dating of the Formation as late Middle Jurassic, probably Bathonian.
相似文献
Michael W. MaischEmail: |
13.
P. Sudha V. Ramprasad M. D. V. Nagendra H. D. Kulkarni N. H. Ravindranath 《Mitigation and Adaptation Strategies for Global Change》2007,12(6):1131-1152
This paper addresses methodological issues in estimating carbon (C) sequestration potential, baseline determination, additionality
and leakage in Khammam district, Andhra Pradesh, southern part of India. Technical potential for afforestation on cultivable
wastelands, fallow, and marginal croplands was considered for Eucalyptus clonal plantations. Field studies for aboveground and belowground biomass, woody litter, and soil organic carbon for baseline
and project scenarios were conducted to estimate the carbon sequestration potential. The baseline carbon stock was estimated
to be 45.3 t C/ha, predominately in soils. The additional carbon sequestration potential under the project scenario for 30 years
is estimated to be 12.8 t C/ha/year inclusive of harvest regimes and carbon emissions due to biomass burning and fertilizer
application. Considering carbon storage in harvested wood, an additional 45% carbon benefit can be accounted. The project
scenario has a higher benefit/cost ratio compared to the baseline scenario. The initial investment cost requirement, however,
is high and lack of access to investment is a significant barrier for adoption of agroforestry in the district.
相似文献
N. H. RavindranathEmail: |
14.
Alexander Golub Jos Cozijnsen Annie Petsonk 《Mitigation and Adaptation Strategies for Global Change》2009,14(5):433-453
This article examines possibilities for linkage between the European Union Emissions Trading System (EU ETS) and Russia, with
a view to enhancing cooperation on a broader scale than the project-based approaches that have been tested thus far. Three
paths for possible EU-Russia linkage are presented by which the Russian Assigned Amount under the Kyoto Protocol can be greened
in order to stimulate emissions trading: 1. Joint implementation—reductions earned via individual projects in Russia; 2. Greened
allowances or green investment schemes; and 3. Linked cap-and-trade systems, in which a Russian domestic emissions trading
system would link with the European Union Emissions Trading System. The authors conclude that the third option, emissions
trading through linked domestic emissions trading systems, offers the best opportunities at the lowest transaction costs.
The authors discuss useful innovative instruments like call options and slip level arrangements on government-to-government
and business-to-business levels.
相似文献
Annie PetsonkEmail: |
15.
An important aspect of present global energy scenarios is the assumption that the amount of biomass that can be grown on the
available area is so limited that a scenario based on biomass as the major source of energy should be unrealistic. We have
been investigating the question whether a Biomass Scenario may be realistic. We found that the global energy demand projected
by the International Energy Agency in the Reference Scenario for the year 2030 could be provided sustainably and economically
primarily from lignocellulosic biomass grown on areas which have been degraded by human activities in historical times. Moreover,
other renewable energies will contribute to the energy mix. There would be no competition with increasing food demand for
existing arable land. Afforestation of degraded areas and investment for energy and fuel usage of the biomass are not more
expensive than investment in energy infrastructure necessary up to 2030 assumed in the fossil energy based Reference Scenario,
probably much cheaper considering the additional advantages such as stopping the increase of and even slowly reducing the
CO2 content of the atmosphere, soil, and water conservation and desertification control. Most importantly, investment for a Biomass
Scenario would be actually sustainable, in contrast to investment in energy-supply infrastructure of the Reference Scenario.
Methods of afforestation of degraded areas, cultivation, and energetic usage of lignocellulosic biomass are available but
have to be further improved. Afforestation can be started immediately, has an impact in some few years, and may be realized
in some decades.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
相似文献
Jürgen O. MetzgerEmail: |
16.
Kenneth T. Gillingham Steven J. Smith Ronald D. Sands 《Mitigation and Adaptation Strategies for Global Change》2008,13(7):675-701
In the coming century, modern bioenergy crops have the potential to play a crucial role in the global energy mix, especially
under policies to reduce carbon dioxide emissions as proposed by many in the international community. Previous studies have
not fully addressed many of the dynamic interactions and effects of a policy-induced expansion of bioenergy crop production,
particularly on crop yields and human food demand. This study combines an updated agriculture and land use (AgLU) model with
a well-developed energy-economic model to provide an analysis of the effects of bioenergy crops on energy, agricultural and
land use systems. The results indicate that carbon dioxide mitigation policies can stimulate a large production of bioenergy
crops, dependent on the level of the policy. This production of bioenergy crops can lead to several impacts on the agriculture
and land use system: decreases in forestland and unmanaged land, decreases in the average yield of food crops, increases in
the prices of food crops, and decreases in the level of human demand of calories.
相似文献
Steven J. Smith (Corresponding author)Email: |
17.
Veronika Dornburg Gregg Marland 《Mitigation and Adaptation Strategies for Global Change》2008,13(3):211-217
Kirschbaum (Mitig Adapt Strat Glob Change 11:1151–1164, 2006) explores the climatic impact over time of temporarily sequestering carbon from the atmosphere. He concludes that temporary
storage of carbon in the terrestrial biosphere “achieves effectively no climate-change mitigation”. His strongly worded statement
begs for a response. This paper argues that Kirschbaum’s conclusion is an artifact of the specific perspective of his analysis
and his choice of a definition for climate-change impact. Even temporary sinks put us on a lower path for climate change,
a path that will not otherwise be accessible. For carbon sinks in the terrestrial biosphere, we argue that sooner is better
and longer is better, but even known temporary sinks have value.
相似文献
Gregg Marland (Corresponding author)Email: |
18.
Kirsten Halsnæs Priyadarshi Shukla 《Mitigation and Adaptation Strategies for Global Change》2008,13(2):105-130
The paper presents a number of ideas on how climate change policy implementation in developing countries can be supported
by alternative international cooperation mechanisms that are based on stakeholder interests and policy priorities including
broader economic and social development issues. It includes a brief review of current development policies, technological
research and promotion efforts, and climate change that demonstrates that mutual policy initiatives undertaken by governments
and the private sector actually have major positive impacts on climate change without being initiated by this global policy
concern. Furthermore a number of examples are given on how future development objectives in Brazil, China, and India jointly
can support economic and social goals and global climate change concerns if these goals are taken into consideration and supported
by international cooperative mechanisms. The paper proposes international cooperative mechanisms that can support the implementation
of integrated development and climate change policies. The mechanisms include an international sustainable development (SD)
and Climate Finance Mechanism (SDCFM), technology development and transition programmes, technology standards, and other measures.
相似文献
Priyadarshi Shukla (Corresponding author)Email: |
19.
The double trade-off between adaptation and mitigation for sea level rise: an application of FUND 总被引:6,自引:2,他引:4
Richard S. J. Tol 《Mitigation and Adaptation Strategies for Global Change》2007,12(5):741-753
This paper studies the effects of adaptation and mitigation on the impacts of sea level rise. Without adaptation, the impact
of sea level rise would be substantial, almost wiping out entire countries by 2100, although the globally aggregate effect
is much smaller. Adaptation would reduce potential impacts by a factor 10–100. Adaptation would come at a minor cost compared
to the damage avoided. As adaptation depends on socio-economic status, the rank order of most vulnerable countries is different
than the rank order of most exposed countries. Because the momentum of sea level rise is so large, mitigation can reduce impacts
only to a limited extent. Stabilising carbon dioxide concentrations at 550 ppm would cut impacts in 2100 by about 10%. However,
the costs of emission reduction lower the avoided impacts by up to 25% (average 10%). This is partly due to the reduced availability
of resources for adaptation, and partly due to the increased sensitivity to wetland loss by adaptation.
相似文献
Richard S. J. TolEmail: |
20.
Investigation at the scene of a crime begins with the search for clues. In the case of bloodstains, the most frequently used
reagents are luminol and reduced phenolphthalein (or phenolphthalin that is also known as the Kastle–Meyer colour test). The
limitations of these reagents have been studied and are well known. Household cleaning products have evolved with the times,
and new products with active oxygen are currently widely used, as they are considered to be highly efficient at removing all
kinds of stains on a wide range of surfaces. In this study, we investigated the possible effects of these new cleaning products
on latent bloodstains that may be left at a scene of a crime. To do so, various fabrics were stained with blood and then washed
using cleaning agents containing active oxygen. The results of reduced phenolphthalein, luminol and human haemoglobin tests
on the washed fabrics were negative. The conclusion is that these new products alter blood to such an extent that it can no
longer be detected by currently accepted methods employed in criminal investigations. This inability to locate bloodstains
means that highly important evidence (e.g. a DNA profile) may be lost. Consequently, it is important that investigators are
aware of this problem so as to compensate for it.
相似文献
Fernando Verdú (Corresponding author)Email: |