Contributions to anelasticity in langasite and langatate

Maximization of the quality factors Q of langasite (LGS) and langatate (LGT) is necessary for optimal performance of acoustic resonators of these materials in frequency-control and high-temperature sensing applications. In this report, measurements and least-squares analysis of Q(-1) as a function of ultrasonic frequency and temperature of undoped LGS (100 K to 750 K) and LGT (300 K to 760 K) reveal a superposition of physical effects, including point-defect relaxations and intrinsic phonon-phonon loss. In LGS, these effects are superimposed on a large temperature-dependent background with weak frequency dependence that is interpreted as arising from a relaxation process with a distribution of activation energies. This distributed relaxation is suggested to be a result of anelastic kink migration. No evidence for a significant background of this form is found in the LGT specimen, consistent with the lower measured dislocation etch-pit density of this crystal. The analysis of the dependence of Q(-1) of LGT on frequency and temperature indicates that, at near-ambient temperatures, the damping in this specimen is close to the intrinsic limit determined by phonon-phonon interactions. Piezoelectric/carrier relaxation, which must occur at sufficiently elevated temperatures, is found not to be a significant contribution to Q(-1), relative to defect-related contributions, in either LGS or LGT in the measured range of temperatures

Multiple Gluon Effects in q+qˉ→t+tˉ+Xq+\bar q\to t+\bar t + X at FNAL Energies: Semi-Analytical Results

We apply our Yennie-Frautschi-Suura exponentiated cross section formulas for the parton processes q + {^(} \bar q {^)}{^\prime} \ra q{^\prime}{^\prime} + {^(} \bar q {^)}{^\prime}{^\prime}{^\prime} + n(G) to the process q + \bar q \ra t + \bar t + n(G) at FNAL energies, where G is a QCD gluon. We use semi-analytical methods to compute the ratio $r_{exp}=\sigma_{exp}/\sigma_B$, where $\sigma_{exp}$ is our soft gluon YFS exponentiated cross section and $\sigma_B$ is the Born cross section. For $m_t= 0.176(0.199)$TeV, we get $r_{exp}=1.65(1.48)$, respectively, for $q=u$ for example. These results are not inconsistent with the recent observations by CDF and D0.Comment: 6 pages, latex replaces postscript at archiver's reques

Effects of progesterone on parturition in the tammar, Macropus eugenii

Summary. Tammar wallabies were treated with progesterone injections or implants during late pregnancy to determine whether progesterone withdrawal was essential for parturition. Neither physiological (implanted group) nor pharmacological (injected group) levels of circulating progesterone prevented parturition occurring at about the expected time in about two-thirds of animals that were pregnant. The neonates of both groups were normal in size and weight, but about a third of treated pregnant animals retained their fetuses or aborted. The retained fetuses were retarded in development. Therefore, progesterone treatment had no influence on the duration of gestation, or parturition, in the tammar wallaby, but high progesterone concentrations may interfere with the normal course of development and birth in a proportion of treated animals

International education: a force for peace and cross-cultural understanding?

This paper discusses the notion that the international sojourn has the potential to transform sojourners into cultural mediators who carry the power to improve global relations. A year-long ethnographic study of the adjustment experiences of international postgraduate students in England revealed a universal early enthusiasm for cross-cultural contact that was matched by a widespread adoption of segregated patterns of interacting. The most common friendship networks were described by bonds with conationals, and yet all students attested to an increase in their cultural learning and mindfulness by the end of the sojourn. Nevertheless, intercultural competence was maximised only in those few students who pursued a multicultural strategy of interaction, leading the researcher to call on Higher Education Institutions to instigate policies to encourage lasting cross-cultural contact

Control of Gammaherpesvirus Latency by Latent Antigen-Specific Cd8+ T Cells

The contribution of the latent antigen-specific CD8+ T cell response to the control of gammaherpesvirus latency is currently obscure. Some latent antigens induce potent T cell responses, but little is known about their induction or the role they play during the establishment of latency. Here we used the murine gammaherpesvirus system to examine the expression of the latency-associated M2 gene during latency and the induction of the CD8+ T cell response to this protein. M2, in contrast to the M3 latency-associated antigen, was expressed at day 14 after infection but was undetectable during long-term latency. The induction of the M291–99/Kd CD8+ T cell response was B cell dependent, transient, and apparently induced by the rapid increase in latently infected cells around day 14 after intranasal infection. These kinetics were consistent with a role in controlling the initial “burst” of latently infected cells. In support of this hypothesis, adoptive transfer of an M2-specific CD8+ T cell line reduced the initial load of latently infected cells, although not the long-term load. These data represent the first description of a latent antigen-specific immune response in this model, and suggest that vaccination with latent antigens such as M2 may be capable of modulating latent gammaherpesvirus infection

Tissue Effects in a Randomized Controlled Trial of Short-term Finasteride in Early Prostate Cancer.

BackgroundIn the Prostate Cancer Prevention Trial, finasteride selectively suppressed low-grade prostate cancer and significantly reduced the incidence of prostate cancer in men treated with finasteride compared with placebo. However, an apparent increase in high-grade disease was also observed among men randomized to finasteride. We aimed to determine why and hypothesized that there is a grade-dependent response to finasteride.MethodsFrom 2007 to 2012, we randomized dynamically by intranet-accessible software 183 men with localized prostate cancer to receive 5mg finasteride or placebo daily in a double-blind study during the 4-6weeks preceding prostatectomy. As the primary end point, the expression of a predefined molecular signature (ERβ, UBE2C, SRD5A2, and VEGF) differentiating high- and low-grade tumors in Gleason grade (GG) 3 areas of finasteride-exposed tumors from those in GG3 areas of placebo-exposed tumors, adjusted for Gleason score (GS) at prostatectomy, was compared. We also determined androgen receptor (AR) levels, Ki-67, and cleaved caspase 3 to evaluate the effects of finasteride on the expression of its downstream target, cell proliferation, and apoptosis, respectively. The expression of these markers was also compared across grades between and within treatment groups. Logistic regression was used to assess the expression of markers.FindingsWe found that the predetermined molecular signature did not distinguish GG3 from GG4 areas in the placebo group. However, AR expression was significantly lower in the GG4 areas of the finasteride group than in those of the placebo group. Within the finasteride group, AR expression was also lower in GG4 than in GG3 areas, but not significantly. Expression of cleaved caspase 3 was significantly increased in both GG3 and GG4 areas in the finasteride group compared to the placebo group, although it was lower in GG4 than in GG3 areas in both groups.InterpretationWe showed that finasteride's effect on apoptosis and AR expression is tumor grade dependent after short-term intervention. This may explain finasteride's selective suppression of low-grade tumors observed in the PCPT

Heat dissipation in atomic-scale junctions

Atomic and single-molecule junctions represent the ultimate limit to the miniaturization of electrical circuits. They are also ideal platforms to test quantum transport theories that are required to describe charge and energy transfer in novel functional nanodevices. Recent work has successfully probed electric and thermoelectric phenomena in atomic-scale junctions. However, heat dissipation and transport in atomic-scale devices remain poorly characterized due to experimental challenges. Here, using custom-fabricated scanning probes with integrated nanoscale thermocouples, we show that heat dissipation in the electrodes of molecular junctions, whose transmission characteristics are strongly dependent on energy, is asymmetric, i.e. unequal and dependent on both the bias polarity and the identity of majority charge carriers (electrons vs. holes). In contrast, atomic junctions whose transmission characteristics show weak energy dependence do not exhibit appreciable asymmetry. Our results unambiguously relate the electronic transmission characteristics of atomic-scale junctions to their heat dissipation properties establishing a framework for understanding heat dissipation in a range of mesoscopic systems where transport is elastic. We anticipate that the techniques established here will enable the study of Peltier effects at the atomic scale, a field that has been barely explored experimentally despite interesting theoretical predictions. Furthermore, the experimental advances described here are also expected to enable the study of heat transport in atomic and molecular junctions, which is an important and challenging scientific and technological goal that has remained elusive.Comment: supporting information available in the journal web site or upon reques

More on scattering of Chern-Simons vortices

I derive a general formalism for finding kinetic terms of the effective Lagrangian for slowly moving Chern-Simons vortices. Deformations of fields linear in velocities are taken into account. From the equations they must satisfy I extract the kinetic term in the limit of coincident vortices. For vortices passing one over the other there is locally the right-angle scattering. The method is based on analysis of field equations instead of action functional so it may be useful also for nonvariational equations in nonrelativistic models of Condensed Matter Physics.Comment: discussion around Eq.(45) is generalised, one more condition for the local right-angle scattering is adde