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1.
A temnospondyl ilium from the uppermost Toutunhe Formation (Middle Jurassic, Callovian) of the southern Junggar Basin is described. Among the known temnospondyls it is very unusual in morphology because of its very long and slender shaft. It compares closely only to the ilium of one of the latest known trematosaurids from the Ladinian of southern Germany. The Toutunhe Formation has also yielded vertebrae and skull fragments of temnospondyls which belong to the brachyopid Gobiops from the Upper Jurassic of Mongolia. Brachyopoid ilia do not, however, display a morphology similar to that of the new specimen. It is therefore concluded that this specimen represents a second taxon of temnospondyl from the Toutunhe Formation, which probably represents the latest surviving trematosauroid. The Trematosauroidea, which was hitherto exclusively known from the Lower to early Upper Triassic, therefore joins the Brachyopoidea – and possibly the Capitosauroidea – as another group of temnospondyls which survived the end-Triassic mass extinction. 相似文献
2.
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
相似文献
Joshua B. Smith (Corresponding author)Email: Phone: +1-314-9357033Fax: +1-314-9357361 |
Matthew C. LamannaEmail: |
3.
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: |
4.
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: |
5.
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: |
6.
Community-based vulnerability assessment has often assumed that the local is the relevant level of adaptation to climate change.
This paper suggests that not only do a number of levels from the international to the regional influence which adaptations
can take place locally, but the governance network that is made up by actors on different levels may to a large extent be
formed in responses to globalising factors, such as internationalisation of economies and the changing role of the state.
The paper presents a study of adaptation in reindeer (Rangifier tarandus) herding, forestry and fishing communities in northern Norway, Sweden, and Finland, with a focus on assessing stakeholders’
own perceptions of environmental, socio-political and economic factors that affect them. In general, the paper illustrates
the integration of non-subsistence economies into large and complex interactions where local adaptation is a result of the
sum of stresses impacting individual entrepreneurs, and the potential they have to adapt their practices given governance
(and their access to support) on different scales.
相似文献
E. Carina H. KeskitaloEmail: |
7.
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: |
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.
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: |
10.
Intrageneric differences in the four stereoisomers of stenusine in the rove beetle genus, Stenus (Coleoptera, Staphylinidae) 总被引:1,自引:1,他引:0
Lusebrink I Burkhardt D Gedig T Dettner K Mosandl A Seifert K 《Die Naturwissenschaften》2007,94(2):143-147
Most species of the rove beetle genus Stenus employ the spreading alkaloid stenusine as an escape mechanism on water surfaces. In the case of danger, they emit stenusine
from their pygidial glands, and it propels them over the water very quickly. Stenusine is a chiral molecule with four stereoisomers:
(2′R,3R)-, (2′S,3R)-, (2′S,3S)-, and (2′R,3S)-stenusine. The percentile ratio of these four isomers is only known for the most common species of the genus: Stenus comma. With the intention of determining the stereoisomer ratios of five additional species from the two subgenera, Stenus and Hypostenus, we used GC/mass spectrometry measurements with a chiral phase. The results showed that the ratio differs among the genus. These findings can be a basis for chemotaxonomy. It is also possible
that the biological function of stenusine, e.g., as antibiotic or fungicide, varies with changing stereoisomer composition.
相似文献
Inka LusebrinkEmail: |
11.
Further evidence of nuclear reactions in the Pd/D lattice: emission of charged particles 总被引:1,自引:1,他引:0
Almost two decades ago, Fleischmann and Pons reported excess enthalpy generation in the negatively polarized Pd/D-D2O system, which they attributed to nuclear reactions. In the months and years that followed, other manifestations of nuclear
activities in this system were observed, viz. tritium and helium production and transmutation of elements. In this report,
we present additional evidence, namely, the emission of highly energetic charged particles emitted from the Pd/D electrode
when this system is placed in either an external electrostatic or magnetostatic field. The density of tracks registered by
a CR-39 detector was found to be of a magnitude that provides undisputable evidence of their nuclear origin. The experiments
were reproducible. A model based upon electron capture is proposed to explain the reaction products observed in the Pd/D-D2O system.
相似文献
Pamela A. Mosier-BossEmail: |
12.
Upasna Sharma Anand Patwardhan 《Mitigation and Adaptation Strategies for Global Change》2008,13(8):819-831
Differences in impacts of climate hazards across exposed units are determined by many factors including the severity of the
hazard itself, the population that is exposed to the hazard and the coping capacity of the exposed units to the hazard. Coping
capacity or adaptive capacity results from a combination of development status (generic capacity) and interventions pertinent
to the hazard (specific capacity). This paper explores the extent to which the generic adaptive capacity may explain the variation
in tropical cyclone impacts. Therefore this paper offers an empirical approach by which adaptive capacity may be measured
and validated against actual outcomes. Results not only validate the role of generic adaptive capacity in explaining variations
in impact but also reveal that general development indicators are not very important as far as predicting outcomes is concerned.
Those indicators of development that can be linked to the impact process are significant in explaining and predicting impact.
This can help identify those aspects of generic adaptive capacity which are important from the perspective of policy action
for enhancing adaptive capacity to a particular climate hazard.
相似文献
Anand PatwardhanEmail: |
13.
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: |
14.
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: |
15.
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: |
16.
Serge I. P. Stalpers André R. van Amstel Rob B. Dellink Ivo Mulder Saskia E. Werners Carolien Kroeze 《Mitigation and Adaptation Strategies for Global Change》2008,13(4):359-378
This article discusses an approach for identification and evaluation of short-term greenhouse gas (GHG) emission reduction
options in firms. The approach is based on lessons learnt from a project using Participatory Integrated Assessment (PIA) and
builds on the idea that effective public climate policy for firms requires options that have support from stakeholders and
are practically feasible. Scenarios are used to provide a link with short-term policy developments and a model assists to
communicate quantitative effects of options to participating stakeholders. Our approach can be seen as a first step towards
a framework that meets the need for more systematic approaches to PIAs identifying effective public policies for short-term
GHG emission reduction options in firms. In order to identify effective options for non-carbon dioxide GHG emission reductions,
our approach has been applied to Dutch dairy farms, after which it has been refined. The case study suggests that our approach
can provide balance between practical, context specific issues and scientific-theoretical aspects, thereby avoiding common
pitfalls of participatory research projects to focus too much on either theory or practical issues.
相似文献
Serge I. P. StalpersEmail: |
17.
Ingrid Christine Koch Coleen Vogel Zarina Patel 《Mitigation and Adaptation Strategies for Global Change》2007,12(8):1323-1339
Climate change is a multi-dimensional issue and in terms of adaptation numerous state and non-state actors are involved from
global to national and local scales. The aim of this paper is first to analyse specific institutional networks involved in
climate change predominantly at the national level in South Africa and second to determine how different stakeholders perceive
their role vis-a-vis climate change adaptation. Within the South African context there is a gap in understanding and evaluating
how institutional networks operate and thus the findings of this work may help inform and strengthen such relationships in
the future. Results showed that few institutions fully understand the implications of adaptation and their roles and responsibilities
have not yet been properly defined. Constraints relating to capacity, lack of awareness and poor information flow need to
be addressed. Climate change is perceived as an important issue although problems such as poverty reduction and job creation
remain national priorities. Most importantly this research has demonstrated how adaptation challenges the hierarchical manner
in which government works and a more collaborative approach to climate change adaptation is needed. Adaptation needs to be
mainstreamed and institutional networks need to be strengthened in order for adaptation mechanisms to be effectively implemented.
相似文献
Ingrid Christine KochEmail: |
18.
Development of regional climate mitigation baseline for a dominant agro-ecological zone of Karnataka,India 总被引:1,自引:0,他引:1
P. Sudha D. Subhashree H. Khan G. T. Hedge I. K. Murthy V. Shreedhara N. H. Ravindranath 《Mitigation and Adaptation Strategies for Global Change》2007,12(6):1051-1075
Setting a baseline for carbon stock changes in forest and land use sector mitigation projects is an essential step for assessing
additionality of the project. There are two approaches for setting baselines namely, project-specific and regional baseline.
This paper presents the methodology adopted for estimating the land available for mitigation, for developing a regional baseline,
transaction cost involved and a comparison of project-specific and regional baseline. The study showed that it is possible
to estimate the potential land and its suitability for afforestation and reforestation mitigation projects, using existing
maps and data, in the dry zone of Karnataka, southern India. The study adopted a three-step approach for developing a regional
baseline, namely: (i) identification of likely baseline options for land use, (ii) estimation of baseline rates of land-use
change, and (iii) quantification of baseline carbon profile over time. The analysis showed that carbon stock estimates made
for wastelands and fallow lands for project-specific as well as the regional baseline are comparable. The ratio of wasteland
Carbon stocks of a project to regional baseline is 1.02, and that of fallow lands in the project to regional baseline is 0.97.
The cost of conducting field studies for determination of regional baseline is about a quarter of the cost of developing a
project-specific baseline on a per hectare basis. The study has shown the reliability, feasibility and cost-effectiveness
of adopting regional baseline for forestry sector mitigation projects.
相似文献
N. H. RavindranathEmail: |
19.
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: |
20.
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: |