Fluctuations in the presence of fields -Phenomenological Gaussian approximation and a new class of thermodynamic inequalities-

The work approaches the study of the fluctuations for the thermodynamic systems in the presence of the fields. The approach is of phenomenological nature and developed in a Gaussian approximation. The study is exemplified on the cases of a magnetizable continuum in a magnetoquasistatic field, as well as for the so called discrete systems. In the last case one finds that the fluctuations estimators depends both on the intrinsic properties of the system and on the characteristics of the environment. Following some earlier ideas of one of the authors we present a new class of thermodynamic inequalities for the systems investigated in this paper. In the case of two variables the mentioned inequalities are nothing but non-quantum analogues of the well known quantum Heisenberg (''uncertainty'') relations. Also the obtained fluctuations estimators support the idea that the Boltzmann's constant k has the signification of a generic indicator of stochasticity for thermodynamic systems. Pacs number(s): 05.20.-y, 05.40.-a, 05.70.-a, 41.20.GzComment: preprint, 24 page

Titration of syntaxin1 in Mammalian synapses reveals multiple roles in vesicle docking, priming, and release probability.

Synaptic vesicles undergo sequential steps in preparation for neurotransmitter release. Individual SNARE proteins and the SNARE complex itself have been implicated in these processes. However, discrete effects of SNARE proteins on synaptic function have been difficult to assess using complete loss-of-function approaches. We therefore used a genetic titration technique in cultured mouse hippocampal neurons to evaluate the contribution of the neuronal SNARE protein Syntaxin1 (Stx1) in vesicle docking, priming, and release probability. We generated graded reductions of total Stx1 levels by combining two approaches, namely, endogenous hypomorphic expression of the isoform Stx1B and RNAi-mediated knockdown. Proximity of synaptic vesicles to the active zone was not strongly affected. However, overall release efficiency of affected neurons was severely impaired, as demonstrated by a smaller readily releasable pool size, slower refilling rate of primed vesicles, and lower release probability. Interestingly, dose-response fitting of Stx1 levels against readily releasable pool size and vesicular release probability showed similar Kd (dissociation constant) values at 18% and 19% of wild-type Stx1, with cooperativity estimates of 3.4 and 2.5, respectively. This strongly suggests that priming and vesicle fusion share the same molecular stoichiometry, and are governed by highly related mechanisms

Going chiral: overlap versus twisted mass fermions

We compare the behavior of overlap fermions, which are chirally invariant, and of Wilson twisted mass fermions at full twist in the approach to the chiral limit. Our quenched simulations reveal that with both formulations of lattice fermions pion masses of O(250 MeV) can be reached in practical applications. Our comparison is done at a fixed value of the lattice spacing a=0.123 fm. A number of quantities are measured such as hadron masses, pseudoscalar decay constants and quark masses obtained from Ward identities. We also determine the axial vector renormalization constants in the case of overlap fermions.Comment: 22 pages, 10 figure

Phase II study of single-agent bosutinib, a Src/Abl tyrosine kinase inhibitor, in patients with locally advanced or metastatic breast cancer pretreated with chemotherapy

Background: This phase II study evaluated single-agent bosutinib in pretreated patients with locally advanced or metastatic breast cancer. Patients and methods: Patients received oral bosutinib 400 mg/day. The primary end point was the progression-free survival (PFS) rate at 16 weeks. Secondary end points included objective response rate, clinical benefit rate, 2-year overall survival rate, safety, and changes in levels of bone resorption/formation biomarkers. Results: Seventy-three patients were enrolled and treated. Median time from diagnosis of metastatic disease to initiation of bosutinib treatment was 24.5 months. For the intent-to-treat population, the PFS rate at 16 weeks was 39.6%. Unexpectedly, all responding patients (n = 4) were hormone receptor positive. The clinical benefit rate was 27.4%. The 2-year overall survival rate was 26.4%. The main toxic effects were diarrhea (66%), nausea (55%), and vomiting (47%). Grade 3-4 laboratory aminotransferase elevations occurred in 14 (19%) patients. Myelosuppression was minimal. No consistent changes in the levels of bone resorption/formation biomarkers were seen. Conclusions: Bosutinib showed promising efficacy in prolonging time to progression in chemotherapy-pretreated patients with locally advanced or metastatic breast cancer. Bosutinib was generally well tolerated, with a safety profile different from that of the Src/Abl tyrosine kinase inhibitor dasatinib in a similar patient population.peer-reviewe

A microscopic semiclassical confining field equation for U(1)U(1) lattice gauge theory in 2+1 dimensions

We present a semiclassical nonlinear field equation for the confining field in 2+1--dimensional $U(1)$ lattice gauge theory (compact QED). The equation is derived directly from the underlying microscopic quantum Hamiltonian by means of truncation. Its nonlinearities express the dynamic creation of magnetic monopole currents leading to the confinement of the electric field between two static electric charges. We solve the equation numerically and show that it can be interpreted as a London relation in a dual superconductor.Comment: 21 pages, epsf postscript figures included, full postscript available at ftp://ftp.th.physik.uni-frankfurt.de/pub/cbest/micro.ps.Z or http://www.th.physik.uni-frankfurt.de/~cbest/pub.htm

A Numerical Transfer-Matrix Study of Surface-Tension Anisotropy in Ising Models on Square and Cubic Lattices

We compute by numerical transfer-matrix methods the surface free energy $\tau(T),$ the surface stiffness coefficient $\kappa(T),$ and the single-step free energy $s(T)$ for Ising ferromagnets with $(\infty \times L)$ square-lattice and $(\infty \times L \times M)$ cubic-lattice geometries, into which an interface is introduced by imposing antiperiodic or plus/minus boundary conditions in one transverse direction. These quantities occur in expansions of the angle-dependent surface tension, either for rough or for smooth interfaces. The finite-size scaling behavior of the interfacial correlation length provides the means of investigating $\kappa(T)$ and $s(T).$ The resulting transfer-matrix estimates are fully consistent with previous series and Monte Carlo studies, although current computational technology does not permit transfer-matrix studies of sufficiently large systems to show quantitative improvement over the previous estimates.Comment: 40 pages, 17 figures available on request. RevTeX version 2.

Improved high-temperature expansion and critical equation of state of three-dimensional Ising-like systems

High-temperature series are computed for a generalized $3d$ Ising model with arbitrary potential. Two specific ``improved'' potentials (suppressing leading scaling corrections) are selected by Monte Carlo computation. Critical exponents are extracted from high-temperature series specialized to improved potentials, achieving high accuracy; our best estimates are: $\gamma=1.2371(4)$, $\nu=0.63002(23)$, $\alpha=0.1099(7)$, $\eta=0.0364(4)$, $\beta=0.32648(18)$. By the same technique, the coefficients of the small-field expansion for the effective potential (Helmholtz free energy) are computed. These results are applied to the construction of parametric representations of the critical equation of state. A systematic approximation scheme, based on a global stationarity condition, is introduced (the lowest-order approximation reproduces the linear parametric model). This scheme is used for an accurate determination of universal ratios of amplitudes. A comparison with other theoretical and experimental determinations of universal quantities is presented.Comment: 65 pages, 1 figure, revtex. New Monte Carlo data by Hasenbusch enabled us to improve the determination of the critical exponents and of the equation of state. The discussion of several topics was improved and the bibliography was update

Radiopurity of CaWO4 crystals for direct dark matter search with CRESST and EURECA

The direct dark matter search experiment CRESST uses scintillating CaWO4 single crystals as targets for possible WIMP scatterings. An intrinsic radioactive contami- nation of the crystals as low as possible is crucial for the sensitivity of the detectors. In the past CaWO4 crystals operated in CRESST were produced by institutes in Russia and the Ukraine. Since 2011 CaWO4 crystals have also been grown at the crystal laboratory of the Technische Universit ¨at Mu ¨nchen (TUM) to better meet the requirements of CRESST and of the future tonne-scale multi-material experiment EURECA. The radiopurity of the raw mate- rials and of first TUM-grown crystals was measured by ultra-low background ¿-spectrometry. Two TUM-grown crystals were also operated as low-temperature detectors at a test setup in the Gran Sasso underground laboratory. These measurements were used to determine the crystals’ intrinsic a-activities which were compared to those of crystals produced at other institutes. The total a-activities of TUM-grown crystals as low as 1.23 ± 0.06 mBq/kg were found to be significantly smaller than the activities of crystals grown at other institutes typically ranging between ~ 15 mBq/kg and ~ 35 mBq/kg