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Stumbling Block (stumbling + block)
Selected AbstractsIncreasing ocean temperatures allow tropical fishes to survive overwinter in temperate watersGLOBAL CHANGE BIOLOGY, Issue 2 2010WILL F. FIGUEIRA Abstract The southeast coast of Australia is a global hotspot for increasing ocean temperatures due to climate change. The temperate incursion of the East Australian Current (EAC) is increasing, affording increased connectivity with the Great Barrier Reef. The survival of tropically sourced juveniles over the winter is a significant stumbling block to poleward range shifts of marine organisms in this region. Here we examine the dependence of overwintering on winter severity and prewinter recruitment for eight species of juvenile coral reef fishes which are carried into temperate SE Australia (30,37 °S) by the EAC during the austral summer. The probability of persistence was most strongly influenced by average winter temperature and there was no effect of recruitment strength. Long-term (138 years) data indicate that winter water temperatures throughout this region are increasing at a rate above the global average and predictions indicate a further warming of >2 °C by the end of the century. Rising ocean temperatures are resulting in a higher frequency of winter temperatures above survival thresholds. Current warming trajectories predict 100% of winters will be survivable by at least five of the study species as far south as Sydney (34 °S) by 2080. The implications for range expansions of these and other species of coral reef fish are discussed. [source] Federalism and the Failure of Imperial Reform, 1774,1775HISTORY, Issue 282 2001Neil York The dispute that pitted British imperialists against American colonists was only superficially constitutional. Belief in indivisible sovereignty and the supremacy of crown and parliament, which prevailed at Whitehall and Westminster, became irreconcilable with American aspirations as a result of actual circumstance not theoretical incompatibility. This was clearly demonstrated by the failure of various proposals made in 1774 and 1775 to reform the empire. These proposals sought to improve relations through a better sharing of power that would in some sense federalize the empire. Whether the reformers called for Americans to be seated in parliament or to be allowed an intercolonial congress of their own, the great stumbling block was political not constitutional. Whatever the merits of their plans, the reformers could not satisfy either side, even though both professed to want compromise that would prevent confrontation. In the process a sense of common identity was lost that could not be recovered, at least in the manner suggested by the reformers. Only with the breakdown of the idealized Atlantic community did constitutional differences lead to an impasse. [source] Effect of prolonged hydroxytamoxifen treatment of MCF-7 cells on mitogen activated kinase cascadeINTERNATIONAL JOURNAL OF CANCER, Issue 5 2002Fanjaniriana Rabenoelina Abstract Resistance to the antiestrogen tamoxifen is the main stumbling block for the success of breast cancer therapy. We focused our study on cellular alterations induced by a prolonged treatment with the active tamoxifen metabolite hydroxytamoxifen (OHT). We show that a prolonged OHT treatment (for up to 7 days) led to a progressive increase in the level of phosphorylated p44/42 mitogen activated kinase (MAP kinase) induced by 10,7 M TPA stimulation, without any significant change in the protein level. This effect was also observed in MCF-7 cells grown first in medium containing dextran-coated charcoal-treated FCS (DCC medium) for 20 days prior to OHT treatment, indicating a specific effect of the antiestrogen and not an effect of estrogen deprivation. It was prevented by cotreatment with estradiol and not observed in the estrogen receptor negative HeLa cell line, suggesting that it was mediated by the estrogen receptor. TPA induced phosphorylation of MEK1/2 was also raised by OHT treatment, without any change in their protein level or Raf-1 and H-Ras levels. When the MCF-7R OHT resistant cell line was grown in antiestrogen containing medium, the level of phosphorylated p44/42 MAP kinase was also high but reversed when the antiestrogen was removed. The 2 other MAP kinase, JNK and P38 pathways were not affected in the same way by OHT treatment. In conclusion, our data reveal that a prolonged OHT treatment, by increasing p44/42 MAPK activity, affects a key step in the growth control of MCF-7 cells, although not sufficiently to overcome the growth inhibitory effect of the drug. © 2002 Wiley-Liss, Inc. [source] Consumer Awareness and Willingness to Pay for High-Pressure Processing of Ready-to-Eat FoodJOURNAL OF FOOD SCIENCE EDUCATION, Issue 2 2009Doris T. Hicks ABSTRACT:, Commercial, nonthermal processing of food, such as high hydrostatic-pressure processing (HPP), has increased. The safety and quality of foods produced by HPP has not been well communicated to the public. An online, nationwide consumer survey was implemented to assess awareness of alternative food processing technologies, consumer food safety attitudes and knowledge, and willingness to pay (WTP) for HPP products. The consumer survey was administered by ZoomerangÔ, an online survey clearinghouse. The survey was completed by 1204 adults. Frequencies and crosstabs were calculated on Zoomerang and SPSS used for one-way ANOVA and chi-square analyses. The survey assessed knowledge of HPP, attitudes about new food processing techniques, WTP for HPP foods and demographics. Overall, many demographic characteristics reflected U.S. census population. While traditional methods, that is, canning, freezing, and microwaving were all well recognized by over 80% of respondents, only 8% recognized HPP. Trends indicated an increase in age, education, and income reflected greater food safety knowledge. Regardless of demographics, no survey respondent exhibited knowledge mastery (80%). Given an explanation of HPP and its benefits, 39% of respondents indicated they would be WTP an additional cost, with higher income and education having the most impact. Majority of respondents indicated a WTP of $0.25 to $0.50 regardless of the value of the food product. More respondents were WTP slightly more for a more expensive product. New technologies often encounter a stumbling block in consumer acceptance and processing costs. A consumer's WTP, once they were informed, could encourage industry to look favorably on this technology. [source] The end of progressive politics?PUBLIC POLICY RESEARCH, Issue 3 2008Carey Oppenheim Progressive politics has reached a stumbling block on its path to social change and it is time to identify new ways forward, say Carey Oppenheim and Lisa Harker. [source] Modeling and Selection of Flexible Proteins for Structure-Based Drug Design: Backbone and Side Chain Movements in p38 MAPKCHEMMEDCHEM, Issue 2 2008Jyothi Subramanian Abstract Receptor rearrangement upon ligand binding (induced fit) is a major stumbling block in docking and virtual screening. Even though numerous studies have stressed the importance of including protein flexibility in ligand docking, currently available methods provide only a partial solution to the problem. Most of these methods, being computer intensive, are often impractical to use in actual drug discovery settings. We had earlier shown that ligand-induced receptor side-chain conformational changes could be modeled statistically using data on known receptor,ligand complexes. In this paper, we show that a similar approach can be used to model more complex changes like backbone flips and loop movements. We have used p38 MAPK as a test case and have shown that a few simple structural features of ligands are sufficient to predict the induced variation in receptor conformations. Rigorous validation, both by internal resampling methods and on an external test set, corroborates this finding and demonstrates the robustness of the models. We have also compared our results with those from an earlier molecular dynamics simulation study on DFG loop conformations of p38 MAPK, and found that the results matched in the two cases. Our statistical approach enables one to predict the final ligand-induced conformation of the active site of a protein, based on a few ligand properties, prior to docking the ligand. We can do this without having to trace the step-by-step process by which this state is arrived at (as in molecular dynamics simulations), thereby drastically reducing computational effort. [source] Exploiting the Kubas Interaction in the Design of Hydrogen Storage MaterialsADVANCED MATERIALS, Issue 18 2009Tuan K. A. Hoang Abstract Hydrogen adsorption and storage using solid-state materials is an area of much current research interest, and one of the major stumbling blocks in realizing the hydrogen economy. However, no material yet researched comes close to reaching the DOE 2015 targets of 9,wt% and 80,kg,m,3 at this time. To increase the physisorption capacities of these materials, the heats of adsorption must be increased to ,20,kJ,mol,1. This can be accomplished by optimizing the material structure, creating more active species on the surface, or improving the interaction of the surface with hydrogen. The main focus of this progress report are recent advances in physisorption materials exhibiting higher heats of adsorption and better hydrogen adsorption at room temperature based on exploiting the Kubas model for hydrogen binding: (,2 -H2),metal interaction. Both computational approaches and synthetic achievements will be discussed. Materials exploiting the Kubas interaction represent a median on the continuum between metal hydrides and physisorption materials, and are becoming increasingly important as researchers learn more about their applications to hydrogen storage problems. [source] PREFERENTIAL TRADE AGREEMENTS AND MULTILATERAL TARIFF COOPERATION*INTERNATIONAL ECONOMIC REVIEW, Issue 1 2006Kamal SaggiArticle first published online: 23 JAN 200 Are preferential trade agreements (PTAs) building or stumbling blocks for multilateral trade liberalization? I address this question in an infinitely repeated tariff game between three countries engaged in intraindustry trade under oligopoly. The central result is that when countries are symmetric, a free trade agreement (FTA) undermines multilateral tariff cooperation by adversely affecting the cooperation incentive of the nonmember whereas a customs union (CU) does so via its effect on the cooperation incentives of members. However, when countries are asymmetric with respect to either market size or cost, there exist circumstances where PTAs facilitate multilateral tariff cooperation. [source] Applying the developmental perspective in the psychiatric assessment and diagnosis of persons with intellectual disability: part II , diagnosisJOURNAL OF INTELLECTUAL DISABILITY RESEARCH, Issue 1 2005A. Dosen Abstract Background The descriptive phenomenological categorical psychiatric diagnostic systems that are currently being used in the field of intellectual disability do not adequately provide for the special needs of persons with intellectual disability. Many relevant diagnostic questions are left unanswered or are only partially accounted for. This is particularly true for persons with low developmental levels. Method A solution to these stumbling blocks is sought in enhancing the contemporary categorical diagnostic systems by also applying methods derived from the developmental perspective. Result By taking the levels of emotional and personality development, in addition to other developmental aspects into account, the clinical picture becomes more comprehensible and explainable. Conclusion The integrative diagnosis that results from this combined approach provides an insight into the processes that have led to the disorder and enriches one's understanding of the presentation form of the disorder. This diagnosis is process- rather than symptom-oriented and is particularly useful with persons who have a low level of psychosocial development. [source] E-BUSINESS AND SUPPLY CHAIN MANAGEMENT: AN OVERVIEW AND FRAMEWORK,PRODUCTION AND OPERATIONS MANAGEMENT, Issue 4 2002M. ERIC JOHNSON The web is having a significant impact on how firms interact with each other and their customers. Past stumbling blocks for supply chain integration such as high transaction costs between partners, poor information availability, and the challenges of managing complex interfaces between functional organizations are all dissolving on the web. In this paper, we examine how the web is changing supply chain management. We present a survey of emerging research on the impact of e-business on supply chain management including descriptive frameworks, analytical models, empirical analysis, and case studies. We classify the work into three major categories: e-commerce, e-procurement, and e-col-laboration. [source] | |||||||||||||