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81.
Yeast cell biologists use a variety of fluorescent protein tags for determining protein localization and for measuring protein dynamics using fluorescence recovery after photobleaching (FRAP). Although many modern fluorescent proteins, such as those with photoactivatable and photoconvertible characteristics, have been developed, none has been exploited for studies in budding yeast. We describe here the construction of yeast-tagging vectors containing photoactivatable green fluorescent protein (PA-GFP) for analysis of protein behaviour. We tagged two yeast proteins, Erg6p and Num1p, with PA-GFP and demonstrated specific photoactivation of the fusion proteins in live cells. Fluorescence intensity measurements showed that a short 5 s exposure to 413 nm light is sufficient to produce the maximum level of activated GFP fluorescence. Local photoactivation of cortical Num1p-PA-GFP showed movement of the marked proteins, providing new insights into the behaviour of Num1p at the cell cortex. Since photoactivation can be achieved using standard mercury arc illumination, the PA-GFP tag represents a convenient and economical way to determine protein dynamics in the cell. Thus, the tagging modules should facilitate protein-tracking studies in a wide variety of cell biological processes in yeast.  相似文献   
82.
Governments worldwide should provide incentives for initial large-scale GS projects to help build the knowledge base for a mature, internationally harmonized GS regulatory framework. Health, safety, and environmental risks of these early projects can be managed through modifications of existing regulations in the EU, Australia, Canada, and the U.S. An institutional mechanism, such as the proposed Federal Carbon Sequestration Commission in the U.S., should gather data from these early projects and combine them with factors such as GS industrial organization and climate regime requirements to create an efficient and adaptive regulatory framework suited to large-scale deployment. Mechanisms to structure long-term liability and fund long-term postclosure care must be developed, most likely at the national level, to equitably balance the risks and benefits of this important climate change mitigation technology. We need to do this right. During the initial field experiences, a single major accident, resulting from inadequate regulatory oversight, anywhere in the world, could seriously endanger the future viability of GS. That, in turn, could make it next to impossible to achieve the needed dramatic global reductions in CO2 emissions over the next several decades. We also need to do it quickly. Emissions are going up, the climate is changing, and impacts are growing. The need for safe and effective CO2 capture with deep GS is urgent.  相似文献   
83.
Reservoirs are sometimes managed to meet agricultural and other water demands, while also maintaining streamflow for aquatic species and ecosystems. In the Henrys Fork Snake River, Idaho (USA), irrigation-season management of a headwater reservoir is informed by a flow target in a management reach ~95 km downstream. The target is in place to meet irrigation demand and maintain aquatic habitat within the 11.4 km management reach and has undergone four flow target assignments from 1978 to 2021. Recent changes to irrigation-season management to maximize reservoir carryover warranted investigation into the flow target assignment. Thus, we created a streamflow-habitat model using hydraulic measurements, habitat unit mapping, and published habitat suitability criteria for Brown Trout (Salmo trutta), Rainbow Trout (Oncorhynchus mykiss), and Mountain Whitefish (Prosopium williamsoni). We used model output to compare habitat availability across two management regimes (1978–2017 and 2018–2021). We found that efforts to minimize reservoir releases in 2018–2021 did not reduce mean irrigation-season fish habitat relative to natural flow, but did reduce overall fish habitat variability during the irrigation season compared to streamflow management in 1978–2017. Field observations for this research led to an adjusted flow target in 2020 that moved the target location downstream of intervening irrigation diversions. Using our model output, we demonstrated that moving the location of the target to account for local irrigation diversions will contribute to more consistently suitable fish habitat in the reach. Our study demonstrates the importance of site selection for establishing environmental flow targets.  相似文献   
84.
Alkylresorcinols, resorcinol derivatives with a long hydrocarbon chain at position 5 of the phenolic ring, have been reported to act as antioxidants and protect polyunsaturated fatty acids against peroxidation. Their structures with meta‐dihydroxy substitutions do not, however, support active hydrogen donation and scavenging of peroxyl radicals responsible for propagation of lipid oxidation. This study compares the antioxidant properties of 5‐n‐pentadecylresorcinol and α‐tocopherol using two model systems: (i) the DPPH· model to test their ability for hydrogen atom donation; and (ii) a triacylglycerol oxidation model to test their ability for scavenging peroxyl radicals. In agreement with theoretical expectations, results from both models showed 5‐n‐pentadecylresorcinol to have very low hydrogen donation and peroxyl radical‐scavenging potency. © 2000 Society of Chemical Industry  相似文献   
85.
This paper explores Canada's approach to water governance. It argues that fragmented governance has had negative impacts on Canada's ability to manage water resources adequately (particularly in the context of urbanization, agriculture and resource extraction), and to deal with new issues (such as climate change). Further, it argues that Canada's highly decentralized approach to water governance creates challenges of integration, coordination and data availability. The paper explores possible future strategies for innovations in water governance that may have the potential to improve water management outcomes.  相似文献   
86.
The goal of this article was to examine theoretically important mechanisms of change in psychotherapy outcome across different types of treatment. Specifically, the role of gains in self-understanding, acquisition of compensatory skills, and improvements in views of the self were examined. A pooled study database collected at the University of Pennsylvania Center for Psychotherapy Research, which includes studies conducted from 1995 to 2002 evaluating the efficacy of cognitive and psychodynamic therapies for a variety of disorders, was used. Patient samples included major depressive disorder, generalized anxiety disorder, panic disorder, borderline personality disorder, and adolescent anxiety disorders. A common assessment battery of mechanism and outcome measures was given at treatment intake, termination, and 6-month follow-up for all 184 patients. Improvements in self-understanding, compensatory skills, and views of the self were all associated with symptom change across the diverse psychotherapies. Changes in self-understanding and compensatory skills across treatment were predictive of follow-up symptom course. Changes in self-understanding demonstrated specificity of change to dynamic psychotherapy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
87.
88.
To illustrate the conditions under which successful innovation adoption takes place, this paper focuses on the implementation of information and communication technologies (ICT) through emerging communities in schools. Two types of such communities are described in terms of the degree of participation in the implementation: school-wide communities and enclaves. The article describes implementation practices in four primary schools with reported high ICT use, selected as case-studies. Four criteria, reflecting the domain, personnel relationships, policy and implementation goals and strategies, as well as staff consistency, are employed to outline the existence and types of communities of implementation within these schools. Findings indicate that, although both school-wide communities and enclaves are present in successful schools, enclaves – compared to school-wide communities – are related to lower levels of implementation. Based on these findings the authors discuss policy directions towards the development of school-wide communities as a purposeful implementation strategy to help transition ICT institutionalization from the initiation to the habitualization stage.  相似文献   
89.
Enfuvirtide (ENF) is a fusion inhibitor that prevents the entry of HIV virions into target cells. Studying the characteristics of viral evolution during treatment and after a treatment interruption can lend insight into the mechanisms of viral evolution and fitness. Although interruption of anti-HIV therapy often results in rapid emergence of an archived “wild-type” virus population, previous work from our group indicates that when only ENF is interrupted, viral gp41 continues to evolve forward and resistance mutations are lost due to back-mutation and remodeling of the envelope protein. To examine the co-evolution of gp120 and gp41 during ENF interruption we extend the Bayesian Hierarchical Phylogenetic model (HPM). Current HPMs enforce conditional independence across all outcomes while biologically all gene regions within a patient should return the same tree unless recombination confers an evolutionary selective advantage. A two-way-interaction HPM is proposed that provides middle ground between these two extremes and allows us to test for differences in evolutionary pressures across gene regions in multiple patients simultaneously. When the model is applied to a well-characterized cohort of HIV-infected patients interrupting ENF we find that across patients, the virus continued to evolve forward in both gene regions. Overall, the hypothesis of independence over dependence between the gene regions is supported. Models that allow for the examination of co-evolution over time will be increasingly important as more therapeutic classes are developed, each of which may impact other through novel and complex mechanisms.  相似文献   
90.
Wear and corrosion are the most important factors that the surface of the engineering parts must confront. The need for protection and improvement of the mechanical characteristics of the surface of engineering parts can be to some extent satisfied by coatings. Coatings are considered as an excellent solution when resistance to corrosion, oxidation or low friction is demanded, but due the complexity of selecting the appropriate one, engineers often avoid them. The need for simultaneous consideration of qualitative and quantitative properties, render the use of classic material selection theories inadequate. An expert system for coating selection is presented in this paper, which can handle both qualitative and quantitative variables. The mathematical model used combines the multi-criteria decision making theories (MCDM) together with the fuzzy sets theory. The “Max-Min set” method is applied to calculate the ordering value of the alternatives while the TOPSIS method is used to rank them. A numerical example is provided to illustrate the method. Finally, the process presented can be easily computerized, to create the relative software.  相似文献   
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