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Challenging Case (challenging + case)
Selected AbstractsChinese Choices: A Poliheuristic Analysis of Foreign Policy Crises, 1950,1996FOREIGN POLICY ANALYSIS, Issue 1 2005Patrick James This paper uses the Poliheuristic Theory (PH), developed by Mintz, which incorporates both psychological and rational choice components in a synthesis of these previously isolated approaches, to explain decision making in Chinese foreign policy crises. China is an interesting initial case for this project for two reasons. One is its importance as a permanent member of the UN Security Council and rising superpower. The other is China's reputation as a nearly unique "black box",an especially challenging case,with regard to decision making in foreign policy crises. Taken from the authoritative compilation of the International Crisis Behavior (ICB) Project, the nine cases (with available data) in which China is a crisis actor span the period from 1950 to 1996. A comparative analysis of Chinese decision making in times of crisis is used to test hypotheses derived from the PH. The hypotheses focus on how decisions are anticipated to occur over two stages. Principal expectations are that the non compensatory rule, which places priority on political considerations, will determine viable alternatives at the first stage, while choices more in line with expected value maximization or lexicographic ordering will characterize the second stage. [source] Simulation of shallow flows over variable topographies using unstructured gridsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 5 2006A. Mohammadian Abstract Simulation of shallow flows over variable topographies is a challenging case for most available shock-capturing schemes. This problem arises because the source terms and flux gradients are not balanced in the numerical computations. Treatments for this problem generally work well on structured grids, but they are usually too expensive, and most of them are not directly applicable to unstructured grids. In this paper we propose two efficient methods to treat the source terms without upwinding and to satisfy the compatibility condition on unstructured grids. In the first method, the calculation of the bed slope source term is performed by employing a compatible approximation of water depth at the cell interfaces. In the second one, different components of the bed slope term are considered separately and a compatible discretization of the components is proposed. The present treatments are applicable for most schemes including the Roe's method without changing the performance of the original scheme for smooth topographies. Copyright © 2006 John Wiley & Sons, Ltd. [source] How Pervasive are Euro-Politics?JCMS: JOURNAL OF COMMON MARKET STUDIES, Issue 2 2000Effects of EU Membership on a New Member State While the consequences of becoming an EU Member State for national policies are usually the core concern of pre-membership debates and of post-accession assessments, studies of the effects of European integration on the political systems of the Member States have so far been less numerous. Among the new EU members, which are ideal cases for studying domestic accession effects, Austria is a particularly challenging case in terms of top-down impact on the national political system. A number of specific precautions were taken in order to protect typical features of the national political system (notably the traditional roles of parliament, Länder and social partners) from being eroded in the multi-level system. The basic research question of this article is whether or not these measures were actually successful. How ,sticky' is the EU upon closer inspection, i.e. how pervasive are its effects on adverse national structures? Can national measures, even at the constitutional level, outweigh specific consequences of participating in Euro-politics? If not 9as the Austrian case indicates), why not? The conclusions distinguish specific Austrian variables from generalizable ones and discuss the findings in the light of the existing literature. [source] A new method for the gradient-based optimization of molecular complexesJOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 9 2009Jan Fuhrmann Abstract We present a novel method for the local optimization of molecular complexes. This new approach is especially suited for usage in molecular docking. In molecular modeling, molecules are often described employing a compact representation to reduce the number of degrees of freedom. This compact representation is realized by fixing bond lengths and angles while permitting changes in translation, orientation, and selected dihedral angles. Gradient-based energy minimization of molecular complexes using this representation suffers from well-known singularities arising during the optimization process. We suggest an approach new in the field of structure optimization that allows to employ gradient-based optimization algorithms for such a compact representation. We propose to use exponential mapping to define the molecular orientation which facilitates calculating the orientational gradient. To avoid singularities of this parametrization, the local minimization algorithm is modified to change efficiently the orientational parameters while preserving the molecular orientation, i.e. we perform well-defined jumps on the objective function. Our approach is applicable to continuous, but not necessarily differentiable objective functions. We evaluated our new method by optimizing several ligands with an increasing number of internal degrees of freedom in the presence of large receptors. In comparison to the method of Solis and Wets in the challenging case of a non-differentiable scoring function, our proposed method leads to substantially improved results in all test cases, i.e. we obtain better scores in fewer steps for all complexes. © 2008 Wiley Periodicals, Inc. J Comput Chem, 2009 [source] Multimodal management, including precisely targeted irradiation, in a severe refractory case of Evans syndromePEDIATRIC BLOOD & CANCER, Issue S5 2006Thomas D. Miale MD Abstract A challenging case of acute autoimmune thrombocytopenia (ITP) which evolved into a chronic refractory case of Evans syndrome over a period of more than 23 years is presented and may illustrate current therapeutic dilemmas now perplexing patients and clinicians. Newer modalities are being developed and their eventual role in the scheme of clinical management remains to be established. While this development unfolds, highly targeted radiotherapy was applied in this case to reduce platelet uptake by a refractory recurrent splenule with the goal of stabilizing the platelet count until promising investigational thrombopoietic agents or other newer, less toxic therapies might become available for wider application. Pediatr Blood Cancer 2006;47:726,728. © 2006 Wiley-Liss, Inc. [source] A Concerted Approach for the Determination of Molecular Conformation in Ordered and Disordered MaterialsCHEMISTRY - A EUROPEAN JOURNAL, Issue 22 2007Jan Sehnert Abstract We present the successful application of a concerted approach for the investigation of the local environment in ordered and disordered phases in the solid state. In this approach we combined isotope labeling with computational methods and different solid-state NMR techniques. We chose triphenylphosphite (TPP) as an interesting example of our investigations because TPP exhibits two crystalline modifications and two different amorphous phases one of which is highly correlated. In particular we analyzed the conformational distribution in three of these phases. A sample of triply labeled 1-[13C]TPP was prepared and 1D MAS as well as wide-line 13C NMR spectra were measured. Furthermore we acquired 2D 13C wide-line exchange spectra and used this method to derive highly detailed information about the phenyl orientation in the investigated TPP phases. For linkage with a structure model a DFT analysis of the TPP molecule and its immediate environment was carried out. The ab initio calculations of the 13C chemical shift tensor in three- and six-spin systems served as a base for the calculation of 1D and 2D spectra. By comparing these simulations to the experiment an explicit picture of all phases could be drawn on a molecular level. Our results therefore reveal the high potential of the presented approach for detailed studies of the mesoscopic environment even in the challenging case of amorphous materials. [source] Molecular diagnosis in dermatopathology: What makes sense, and what doesn'tEXPERIMENTAL DERMATOLOGY, Issue 1 2009Markus Braun-Falco Abstract:, Molecular techniques have provided us with a wealth of information about biological events in healthy individual, and improved tremendously our understanding about the pathogenesis of a huge variety of cutaneous diseases. Those methods have originally been invented to support basic scientific investigations on a molecular level and are translated increasingly into sophisticated diagnostic tools changing the classic paradigm of diagnostic pathology; among them are immunohistochemistry (IHC), polymerase chain reaction (PCR), G-banding, loss of heterozygosity, fluorescence in situ hybridization (FISH), chromogen in situ hybridization (CISH), comparative genomic hybridization on chromosomes and microarray technology. Some of them such as IHC and PCR have already been standardized to a level that allows its utility in daily routine diagnostics for several dermatological diseases. For others like array-based technologies, their optimal indications await to be fully determined. These ancillary methods have the great potential to contribute important new information to challenging cases, and will help to improve diagnostic accuracy particularly in cases in which conventional histopathology is ambiguous. Thus, they will broaden our armamentarium for diagnostic pathology. Herein, some key techniques will be reviewed and their applicability towards the diagnosis of dermatological diseases critically discussed. [source] Does a new undergraduate curriculum based on Tomorrow's Doctors prepare house officers better for their first post?MEDICAL EDUCATION, Issue 12 2003A qualitative study of the views of pre-registration house officers using critical incidents Introduction, In 1994 Manchester University introduced an integrated undergraduate medical course using problem-based learning (PBL) throughout. The study reported here explored whether there were any differences between the new course graduates (NCGs) and the traditional course graduates (TCGs) in the types of scenarios they recalled as ,critical incidents', or challenging cases, while working as pre-registration house officers (PRHOs). The focus is on differences rather than causal links. Method, We used semistructured interviews to generate our data. Twenty-four traditional course graduates and 23 new course graduates were interviewed approximately 3 months after starting their first PRHO placement. Results, We identified 4 types of critical incidents relating to: clinical practice; limitations of competence; emotional involvement; and communication. Traditional course graduates reported difficulties in making patient management decisions, whereas the NCGs were better at dealing with uncertainty, knowing their limits and asserting their rights for support. Communication difficulties and coping with emotional involvement were common across both groups of graduates and hence remain problems in relation to being prepared for the role of a PRHO. Conclusions, Graduates of the new, integrated curriculum seemed to be much better at dealing with uncertainty, knowing their personal limits and asserting their rights for support when they felt these limits had been reached. Communication difficulties and emotional involvement remain major factors in the transition from student to PRHO. [source] EDM,DEDM and protein crystal structure solutionACTA CRYSTALLOGRAPHICA SECTION D, Issue 5 2009Rocco Caliandro Electron-density modification (EDM) procedures are the classical tool for driving model phases closer to those of the target structure. They are often combined with automated model-building programs to provide a correct protein model. The task is not always performed, mostly because of the large initial phase error. A recently proposed procedure combined EDM with DEDM (difference electron-density modification); the method was applied to the refinement of phases obtained by molecular replacement, ab initio or SAD phasing [Caliandro, Carrozzini, Cascarano, Giacovazzo, Mazzone & Siliqi (2009), Acta Cryst. D65, 249,256] and was more effective in improving phases than EDM alone. In this paper, a novel fully automated protocol for protein structure refinement based on the iterative application of automated model-building programs combined with the additional power derived from the EDM,DEDM algorithm is presented. The cyclic procedure was successfully tested on challenging cases for which all other approaches had failed. [source] | ||||||||||||||||