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New Positions (new + position)
Selected AbstractsDFT conformational studies of ,-maltotriose,JOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 7 2008Udo Schnupf Abstract Recent DFT optimization studies on ,-maltose improved our understanding of the preferred conformations of ,-maltose. The present study extends these studies to ,-maltotriose with three ,- D -glucopyranose residues linked by two ,-[1,4] bridges, denoted herein as DP-3's. Combinations of gg, gt, and tg hydroxymethyl groups are included for both "c" and "r" hydroxyl rotamers. When the hydroxymethyl groups are for example, gg-gg-gg, and the hydroxyl groups are rotated from all clockwise, "c", to all counterclockwise, "r", the minimum energy positions of the bridging dihedral angles (,H and ,H) move from the region of conformational space of (,, ,), relative to (0°, 0°), to a new position defined by (+, +). Further, it was found previously that the relative energies of ,-maltose gg-gg-c and "r" conformations were very close to one another; however, the DP-3's relative energies between hydroxyl "c" or "r" rotamers differ by more than one kcal/mol, in favor of the "c" form, even though the lowest energy DP-3 conformations have glycosidic dihedral angles similar to those found in the ,-maltose study. Preliminary solvation studies using COSMO, a dielectric solvation method, point to important solvent contributions that reverse the energy profiles, showing an energy preference for the "r" forms. Only structures in which the rings are in the chair conformation are presented here. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2008 [source] Craniomandibular joint in South American burrowing rodents (Ctenomyidae): adaptations and constraints related to a specialized mandibular position in diggingJOURNAL OF ZOOLOGY, Issue 3 2006D. H. Verzi Abstract A quali-quantitative morphofunctional analysis of the craniomandibular joint in subterranean rodents of the family Ctenomyidae showed that specializations of this joint are coupled with adaptations to digging. The presence of a postglenoid articular region in the skull of Eucelophorus and Ctenomys implies a new position of the mandible in digging, different from those involved in gnawing and chewing. In this third position of the mandible, the mandibular joint is stabilized when the deeply inserted incisors attack the soil or an obstacle, preventing dislocation. The proposed new mandibular function imposes a mechanical constraint on size and shape of the auditory bullae in tooth-digger ctenomyids, because inflated bullae preclude a satisfactory opening of the mandible when it articulates in the postglenoid region. The configuration of the craniomandibular joint and other specializations for digging of Eucelophorus are unique among all South American rodents. The presence of non-homologous, and even more specialized, postglenoid cavities in burrowing rodents of other continents suggests a common requirement for stabilizing the mandibular joint when strong forces with incisors are developed. The less specialized postglenoid region of Eucelophorus and Ctenomys, with respect to that of other rodent clades, may be related to the more recent differentiation of ctenomyids. [source] Transitions in Defense Management Reform: A Review of the Government Accountability Office's Chief Management Officer Recommendation and Comments for the New AdministrationPUBLIC ADMINISTRATION REVIEW, Issue 6 2008Philip J. Candreva The Government Accountability Office believes the answer to the U.S. Defense Department's persistent management problems is to be found in the creation of a new position, chief management officer, to oversee defense business transformation. The recommendation for this position is reviewed and used to raise questions and spur inquiry in the areas of evidence-based reform, the relationship between policy and administration, auditor overreach, and sustaining reforms through transition. The latter portion is expanded in this time of transition, and recommendations are made to the new administration to develop a management agenda, to the defense career executives to facilitate the transition, and to the next comptroller general to consider how the Government Accountability Office's varied roles produce outputs that align with the desired outcomes in both the policy and administration domains. [source] Conducting fieldwork with Tarieng communities in southern Laos: Negotiating discursive spaces between neoliberal dogmas and Lao socialist ideologyASIA PACIFIC VIEWPOINT, Issue 2 2010Steeve Daviau Abstract Based on research with ethnic minorities in Laos aimed at understanding how they cope with and negotiate political and economic ,double domination', this article examines the experiences of prolonged fieldwork in a remote Tarieng area in the Annam Range, southern Laos. After briefly reviewing Lao ethnographical policy and practice regarding ethnic minorities, I introduce the Tarieng people. I detail how I initially gained access to these local communities via long-term engagement with a range of development project initiatives. Then, after eight years of conducting such fieldwork in a Tarieng area ,below the radar of the state', I managed to obtain official authorisations to continue research as a graduate student. In this new position, I accessed the field via different negotiations with central, provincial and local official bureaucracies. After detailing this process, back in the field I reveal my strategies to create a discursive space that has allowed me to access dissident Tarieng voices and agency. Finally, I highlight four central elements that have continued to shape my field research: language proficiency, working with research assistants, awareness of political relations and cultural sensitivity, and ethical concerns. These have emerged while the possibilities and constraints of political engagement with the Tarieng people are explored. [source] Efficient transposition of a single Minos transposon copy in the genome of the ascidian Ciona intestinalis with a transgenic line expressing transposase in eggsDEVELOPMENTAL DYNAMICS, Issue 4 2010Akiko Hozumi Abstract Transgenesis with transposons is an important technique for studying genetic functions. In the ascidian Ciona intestinalis, methods for germline transformation with the Tc1/mariner transposon Minos have been established. A system to remobilize a single Minos copy in the genome is needed to refine this transgenic technique. In this study, such an experimental system was established with a transgenic line expressing Minos transposase in eggs. In the eggs of a double transgenic animal from a cross between the egg transposase line and a transgenic line having a single Minos insertion, the transposon was transposed into new positions of the Ciona genome, thus creating new insertions. Some of the new insertions caused enhancer detection. The majority of the new insertion sites were mapped on different chromosomes from that of the transposon donor. This characteristic of Minos is in contrast to that of the Sleeping Beauty transposon, which causes frequent intrachromosomal transposition. Developmental Dynamics 239:1076,1088, 2010. © 2010 Wiley-Liss, Inc. [source] A micromechanical study of rolling and sliding contacts in assemblies of oval granulesINTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 5 2003Hossein M. Shodja Abstract The evolution of the microstructure of an assembly of cohesionless granular materials with associated pores, which carry the overall applied stresses through frictional contacts is a complex phenomenon. The macroscopic flow of such materials take place by the virtue of the relative rolling and sliding of the grains on the micro-scale. A new discrete element method for biaxial compression simulations of random assemblies of oval particles with mixed sizes is introduced. During the course of deformation, the new positions of the grains are determined by employing the static equilibrium equations. A key aspect of the method is that, it is formulated for ellipse cross-sectional particles, hence desirable inherent anisotropies are possible. A robust algorithm for the determination of the contact points between neighbouring grains is given. Employing the present methodology, many aspects of the behaviour of two-dimensional assemblies of oval cross-sectional rods have been successfully addressed. The effects of initial void ratio, interparticle friction angle, aspect ratio, and bedding angle on the rolling and sliding contacts are examined. The distribution of normals to the rolling and sliding contacts have different patterns and are concentrated along directions, which are approximately perpendicular to one another. On the other hand, the distribution of all contact normals (combined rolling and sliding) are close to that of rolling contacts, which confirm that rolling is the dominant mechanism. This phenomenon becomes more pronounced for higher intergranular friction angle. Characteristics of the rolling and sliding contacts are also discussed in the context of the force angle, which is the inclination of contact force with respect to the contact normal. Copyright © 2003 John Wiley & Sons, Ltd. [source] Two novel somatic mutations in the human interleukin 6 promoter region in a patient with sporadic breast cancerINTERNATIONAL JOURNAL OF IMMUNOGENETICS, Issue 6 2003A. Saha Summary Two new single nucleotide mutations were observed within the promoter region of human interleukin-6 gene (IL-6) in the tumour sample of a patient with sporadic breast cancer, which was a somatic change. Both mutations, one at ,125 (C > G) and the other at position ,173 (G > T) from the translation start site, were transversions observed at new positions, not reported earlier. In addition to these two novel mutations in this patient, a known somatic polymorphism was also observed at position ,174 (G > C) (from the transcription initiation site, redesignated as ,236 from the translational initiation site as per the HUGO nomenclature). Further, a preliminary comparative analysis of the studied promoter region by the ,ConsInspector 3.0' program, where the mutated sequence (AF362378) was compared with the sequence existing in the database (Y00081), depicted the presence of the variations in putative binding sites for transcription factors such as glucocorticoid response element (GRE) and nuclear factor kappa-B (NF,-B), which could lead to differential expression of this gene. [source] Optimizing precision of rotating compensator ellipsometryPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 5 2008L. Broch Abstract We present a method especially adapted to the RCE ellipsometer in the PCSA configuration (Polarizer, Compensator, Sample, Analyzer) when measurements with high degree of accuracy are required. The optimum precision conditions can be achieved for any sample by an adjustement of the azimuth of the analyzer and the polarizer. This new method of tracking is used to minimize the random errors and new positions of the analyzer and the polarizer according the sample are given. In these cases, the variances of tan , and tan , can be divided up to five. Experimental verification of error reductions is also achieved. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Momentum Trading by InstitutionsTHE JOURNAL OF FINANCE, Issue 6 2002S.G. Badrinath We document the equity trading practices of approximately 1,200 institutions from the third quarter of 1987 through the third quarter of 1995. We decompose trading by institutions into the initiation of new positions (entry), the termination of previous positions (exit), and adjustments to ongoing holdings. Institutions act as momentum traders when they enter stocks but as contrarian traders when they exit or make adjustments to ongoing holdings. We find significant differences in trading practices among different types of institutions. [source] | |||||||||||||