Drug Policy and the HIV Pandemic in Russia and Ukraine

Over the past three years Russia and Ukraine have experienced one of the fastest growing HIV pandemics in Europe. In contrast to other parts of the world, the main driver behind the rate of infection is injecting drug use. Recent government policies have placed a heavy emphasis on reducing availability and on harsh punishments for drug users. This approach has not succeeded in significantly reducing the level of drug use. It has pushed the drug scene underground and increased risky behaviours among vulnerable groups. In the absence of measures to reduce infections and reverse the rate of transmission, the long-term impact of HIV/AIDS on population growth and economic development is likely to be grave

The evolutionary history of the Arabidopsis arenosa complex : diverse tetraploids mask the Western Carpathian center of species and genetic diversity

The Arabidopsis arenosa complex is closely related to the model plant Arabidopsis thaliana. Species and subspecies in the complex are mainly biennial, predominantly outcrossing, herbaceous, and with a distribution range covering most parts of latitudes and the eastern reaches of Europe. In this study we present the first comprehensive evolutionary history of the A. arenosa species complex, covering its natural range, by using chromosome counts, nuclear AFLP data, and a maternally inherited marker from the chloroplast genome [trnL intron (trnL) and trnL/F intergenic spacer (trnL/F-IGS) of tRNALeu and tRNAPhe, respectively]. We unravel the broad-scale cytogeographic and phylogeographic patterns of diploids and tetraploids. Diploid cytotypes were exclusively found on the Balkan Peninsula and in the Carpathians while tetraploid cytotypes were found throughout the remaining distribution range of the A. arenosa complex. Three centers of genetic diversity were identified: the Balkan Peninsula, the Carpathians, and the unglaciated Eastern and Southeastern Alps. All three could have served as long-term refugia during Pleistocene climate oscillations. We hypothesize that the Western Carpathians were and still are the cradle of speciation within the A. arenosa complex due to the high species number and genetic diversity and the concurrence of both cytotypes there

First Order Calculation of the Inclusive Cross Section pp to ZZ by Graviton Exchange in Large Extra Dimensions

We calculate the inclusive cross section of double Z-boson production within large extra dimensions at the Large Hadron Collider (LHC). Using perturbatively quantized gravity in the ADD model we perform a first order calculation of the graviton mediated contribution to the pp to ZZ cross section. At low energies (e.g. Tevatron) this additional contribution is very small, making it virtually unobservable, for a fundamental mass scale above 2500 GeV. At LHC energies however, the calculation indicates that the ZZ-production rate within the ADD model should differ significantly from the Standard Model if the new fundamental mass scale would be below 15000 GeV. A comparison with the observed production rate at the LHC might therefore provide direct hints on the number and structure of the extra dimensions.Comment: 7 pages, 7 figures, accepted for publication in Phys. Rev.

Evidence for Diverging Barriers in the Disordered Vortex Solid in the K,Ba BiO3 Superconducting Oxide

International audienceVortex dynamics has been investigated in the cubic K, Ba BiO3 superconductor using ac susceptibility measurements on a large frequency range 0.03 Hz , v , 60 kHz . Power law diverging barriers have been obtained on both sides of the order-disorder transition line. The m exponent remains close to 5 2 (elastic creep value) in some part of the disordered phase and finally decreases at high temperature and/or high field, in good agreement with the recent plastic collective creep theory [J. Kierfeld, H. Nordborg, and V. M. Vinokur, Phys. Rev. Lett., 85, 4948 (2000)]

Thermodynamics of the vortex liquid in heavy ion-irradiated superconductors

It is shown that the large effect of heavy ion-irradiation on the thermodynamical properties of the anisotropic superconductor YBa$_{2}$Cu$_{3}$O$_{7-\delta}$ extends well into the superconducting fluctuation regime. The presence of the induced amorphous columnar defects shifts the specific heat maximum at the normal-to-superconducting transition. This effect is similar to that recently put into evidence in cubic K$_{x}$Ba$_{1-x}$BiO$_{3}$ ($x \simeq 0.35$). In both compounds, vortex pinning manifests itself as a sharp angular dependence of the \em equilibrium \rm torque. In YBa$_{2}$Cu$_{3}$O$_{7-\delta}$, pinning by the defects appears at the temperature $T_{C_{p}}^{max}$ of the specific heat maximum, well above the magnetic irreversibility line $T_{irr}(H)$. In isotropic K$_{x}$Ba$_{1-x}$BiO$_{3}$, the onset of the pinning-related torque anomaly tracks the onset of the specific heat anomaly and the irreversibility line. In YBa$_{2}$Cu$_{3}$O$_{7-\delta}$, fluctuations of the amplitude of the order parameter (and not vortex line wandering) are ultimately responsible for the vanishing of pinning. In K$_{x}$Ba$_{1-x}$BiO$_{3}$, vortex pinning disappears only at the superconducting-to-normal transition. The results indicate that in both compounds, the pinning energy at the ``Bose glass'' transition is large with respect to the total free energy gain in the superconducting state. By implication, the mechanism of this latter transition should be reconsidered.Comment: 9 pages, 9 figures, resubmitted to PRB 23-09-200

A Novel Algorithm for the Determination of Walker Damage in Loaded Disc Springs

In this paper, a novel algorithm for the determination of Walker damage in loaded disc springs is presented. The algorithm takes a 3D-scan of a disc spring, measured residual stresses, material parameters, and spring loads as inputs. It outputs a distribution of Walker damage over the surface area of the input disc spring. As the algorithm allows a fully automated determination of the Walker damage, it can be used by disc spring manufacturers to reduce the working time spent on this task by specialized engineers significantly. Compared to spreadsheet applications using analytical formulas and finite element models using idealized geometry, this approach offers a superior description of the stress states in disc springs

Die Zwischenwahlen in Argentinien: ein Sieg für Präsident Kirchner und viele offene Fragen

Am 23. Oktober 2005 waren landesweit knapp 26 Mio. Argentinier dazu aufgerufen, in Zwischenwahlen 127 der 257 Mitglieder des Unterhauses neu zu bestimmen. In acht der 24 Provinzen wurden zur gleichen Zeit Senatoren für den nationalen Kongress gewählt. Neben verschiedenen Entscheidungen auf lokaler Ebene fanden zudem in elf Gliedstaaten Wahlen zu den Provinzparlamenten statt. Wenn auch nicht ganz so durchschlagend wie von ihm erhofft, so war Néstor Kirchner doch der Sieger des Wahlsonntags. Nach der Hälfte seiner Amtszeit sieht der Präsident vor allem seine Position gegenüber Eduardo Duhalde gestärkt. Sein direkter Vorgänger in der Casa Rosada und ehemaliger Förderer, der zu seinem stärksten Widersacher innerhalb der peronistischen Bewegung geworden war, musste sich in der Provinz von Buenos Aires, seiner Machtbasis, geschlagen geben. Angesichts der schwachen und zersplitterten Opposition als auch der vorerst weiterhin voranschreitenden wirtschaftlichen Erholung spricht momentan alles für den Sieg eines Peronisten bei den Präsidentschaftswahlen 2007. Kirchner hat sich noch nicht festgelegt, ob er eine zweite Amtszeit anstrebt. Es wäre aber überraschend, sollte er sich nicht zur Widerwahl stellen. (Brennpkt. Lat.am/DÜI