K-theory for ternary structures

Ziel dieser Arbeit ist es K-Theorie für JB*-Tripelsysteme zu definieren. Dies sind Banachräume, versehen mit einem dreifachen Produkt, die als Kategorie äquivalent zu den beschränkten symmetrischen Gebieten in Banachräumen sind, die einen Basispunkt haben. Da JB*-Tripelsysteme im Allgemeinen keine eindeutige Operatorraumstruktur besitzen, definieren wir zunächst eine K-Theorie für sogenannte ternäre Ringe von Operatoren (kurz TROs), die diese Einschränkung nicht haben. Als Anwendung klassifizieren wir die induktiven Limiten endlichdimensionaler TROs. Als nächstes betten wir jedes JB*-Tripelsystem in seinen universellen einhüllenden TRO ein, dessen Existenz wir beweisen. Diese Zuordnung ist funktoriell und erlaubt uns, die K-Theorie eines JB*-Tripelsystems als K-Theorie seines universellen einhüllenden TROs zu definieren. Nachdem wir die universellen einhüllenden TROs der endlichdimensionalen Cartanfaktoren bestimmt haben, gelingt es uns mit einer K-theoretischen Version der Wurzelsysteme alle endlichdimensionalen, treu darstellbaren JB*-Tripelsysteme zu klassifizieren

Collective Excitations of (154)Sm nucleus at FEL{gamma}+LHC Collider

The production of collective excitations of the (154)Sm at FEL{gamma}+LHC collider is investigated. We show that this machine will be a powerful tool for investigation of high energy level excitations.Comment: 6 pages, 1 figure, 4 table

Competing electric and magnetic excitations in backward electron scattering from heavy deformed nuclei

Important $E2$ contributions to the $(e,e^{\prime})$ cross sections of low-lying orbital $M1$ excitations are found in heavy deformed nuclei, arising from the small energy separation between the two excitations with $I^{\pi}K = 2^+1$ and 1$^+1$, respectively. They are studied microscopically in QRPA using DWBA. The accompanying $E2$ response is negligible at small momentum transfer $q$ but contributes substantially to the cross sections measured at $\theta = 165 ^{\circ}$ for $0.6 < q_{\rm eff} < 0.9$ fm$^{-1}$ ($40 \le E_i \le 70$ MeV) and leads to a very good agreement with experiment. The electric response is of longitudinal $C2$ type for $\theta \le 175 ^{\circ}$ but becomes almost purely transverse $E2$ for larger backward angles. The transverse $E2$ response remains comparable with the $M1$ response for $q_{\rm eff} > 1.2$ fm$^{-1}$ ($E_i > 100$ MeV) and even dominant for $E_i > 200$ MeV. This happens even at large backward angles $\theta > 175 ^{\circ}$, where the $M1$ dominance is limited to the lower $q$ region.Comment: RevTeX, 19 pages, 8 figures included Accepted for publication in Phys Rev

Medical education reform in Tajikistan: comparison of the conventional one-year family medicine residency program and the new two-year residency program for postgraduate medical education

INTRODUCTION: The last two decades have seen a shift in former Soviet countries from highly specialized to more family medicine-focused systems. Medical education has slowly adjusted to these reforms, although the region is still at risk to have a chronic shortage of family doctors. This paper presents the evaluation of a new post-graduate family medicine program in Tajikistan, focused on competency-based training. The findings are relevant for policy makers, international organizations and practitioners participating in similar medical education reform programs. METHODS: We employed a quasi-experimental control group design and compared intervention residents, control group residents with traditional training, and 1st year residents with no training in two outcomes, clinical knowledge and competencies. We employed two objective measures, a written multiple-choice question test (MCQT) and an Objective Structured Clinical Examination (OSCE), respectively. We report reliability and validity of the measures along with ANOVA, planned contrasts and effect size estimates to examine differences across groups. RESULTS: We found statistically significant differences in both clinical knowledge and competencies between intervention and control groups. We also detected a large intervention effect size. Participants in the intervention outperformed control group participants in the two measures. Our analysis suggests that intervention and control group participants are comparable in terms of initial knowledge and competencies, strengthening the argument that the intervention caused the improvement in the program outcomes. DISCUSSION: Receiving tailored training and structured opportunities to practice knowledge and competencies in clinical settings have a positive effect on the education of family medicine doctors in Tajikistan. Our results support curriculum reform and investment in medical education in the form of longer and supervised on-the-job preparation designed to be more in line with international standards. We discuss suggestions for future studies and potential requirements to inform replicability in other countries. CONCLUSION: Family medicine is well recognized as central to health systems throughout the world, but high quality residency training lags behind in some countries. Our study showed that investing in family medicine residency programs and structured training is effective in increasing critical clinical competencies. We encourage promoting comprehensive post graduate family medicine doctor training so that the goals of a family medicine centered health system are attainable

Orbital current mode in elliptical quantum dots

An orbital current mode peculiar to deformed quantum dots is theoretically investigated; first by using a simple model that allows to interpret analytically its main characteristics, and second, by numerically solving the microscopic equations of time evolution after an initial perturbation within the time-dependent local-spin-density approximation. Results for different deformations and sizes are shown.Comment: 4 REVTEX pages, 4 PDF figures, accepted in PRB:R

Universality of Symmetry and Mixed-symmetry Collective Nuclear States

The global correlation in the observed variation with mass number of the $E2$ and summed $M1$ transition strengths is examined for rare earth nuclei. It is shown that a theory of correlated $S$ and $D$ fermion pairs with a simple pairing plus quadrupole interaction leads naturally to this universality. Thus a unified and quantitative description emerges for low-lying quadrupole and dipole strengths.Comment: In press, Phys. Rev. Lett. 199

Conformational Changes in Pediocin AcH upon Vesicle Binding and Approximation of the Membrane-Bound Structure in Detergent Micelles

Pediocin AcH is a 44-residue antimicrobial peptide with bactericidal potency against Gram-positive bacteria such as Listeria. It belongs to a family of bacteriocins that, when membrane-associated, is predicted to contain β-sheet and α-helical regions. All bacteriocins in this family have a conserved N-terminal disulfide bond. An additional C-terminal disulfide bond in pediocin AcH is thought to confer enhanced potency and broader specificity range against sensitive bacteria. The C-terminal disulfide bond may also affect the conformation of the C-terminus. The secondary structures of pediocin AcH in aqueous solution and vesicles from susceptible cells, as well as the ability of trifluoroethanol (TFE) and detergent systems to induce secondary structures like those induced in vesicles, were studied by circular dichroism (CD) spectroscopy. Like related peptides, pediocin AcH was highly unordered in aqueous solution, 56%. However, it also contained 20% β-strand and 15% β-turn structures. Upon complete binding to vesicles, 32% α-helical structure formed, the unordered structure decreased to 32%, and the β-strand and β-turn structures remained largely unchanged. Thus, a βα domain structure formed in vesicles. The helical structure likely forces the C-terminal tail to loop back on the helix so that the C24−C44 disulfide bond can form. Detergent micelles were superior to TFE in their ability to induce secondary structural fractions in pediocin AcH comparable to those observed in vesicles. This demonstrates the importance of a hydrocarbon−water interface to pediocin AcH structure induction and suggests that it is preferable to use detergent micelles as solvents in NMR studies of pediocin AcH structure

Orbital Magnetic Dipole Mode in Deformed Clusters: A Fully Microscopic Analysis

The orbital M1 collective mode predicted for deformed clusters in a schematic model is studied in a self-consistent random-phase-approximation approach which fully exploits the shell structure of the clusters. The microscopic mechanism of the excitation is clarified and the close correlation with E2 mode established. The study shows that the M1 strength of the mode is fragmented over a large energy interval. In spite of that, the fraction remaining at low energy, well below the overwhelming dipole plasmon resonance, is comparable to the strength predicted in the schematic model. The importance of this result in view of future experiments is stressed.Comment: 10 pages, 3 Postscript figures, uses revte