The soft and the hard pomerons in hadron elastic scattering at small t

We consider simple-pole descriptions of soft elastic scattering for pp, pbar p, pi+ p, pi- p, K+ p and K- p. We work at t and s small enough for rescatterings to be neglected, and allow for the presence of a hard pomeron. After building and discussing an exhaustive dataset, we show that simple poles provide an excellent description of the data in the region - 0.5 GeV^2 < t < -0.1 GeV^2, 6 GeV<sqrt(s)< 63 GeV. We show that new form factors have to be used, and get information on the trajectories of the soft and hard pomerons.Comment: 27 pages, 9 figures, LaTeX. A few typos fixed, and references correcte

First-principles study of lattice instabilities in the ferromagnetic martensite Ni2_2MnGa

The phonon dispersion relations and elastic constants for ferromagnetic Ni$_2$MnGa in the cubic and tetragonally distorted Heusler structures are computed using density-functional and density-functional perturbation theory within the spin-polarized generalized-gradient approximation. For $0.9<c/a<1.06$, the TA$_2$ tranverse acoustic branch along $[110]$ and symmetry-related directions displays a dynamical instability at a wavevector that depends on $c/a$. Through examination of the Fermi-surface nesting and electron-phonon coupling, this is identified as a Kohn anomaly. In the parent cubic phase the computed tetragonal shear elastic constant, C$^\prime$=(C$_{11}-$C$_{12}$)/2, is close to zero, indicating a marginal elastic instability towards a uniform tetragonal distortion. We conclude that the cubic Heusler structure is unstable against a family of energy-lowering distortions produced by the coupling between a uniform tetragonal distortion and the corresponding $[110]$ modulation. The computed relation between the $c/a$ ratio and the modulation wavevector is in excellent agreement with structural data on the premartensitic ($c/a$ = 1) and martensitic ($c/a$ = 0.94) phases of Ni$_2$MnGa.Comment: submitted to Phys. Rev.

LHC Predictions from a Tevatron Anomaly in the Top Quark Forward-Backward Asymmetry

We examine the implications of the recent CDF measurement of the top-quark forward-backward asymmetry, focusing on a scenario with a new color octet vector boson at 1-3 TeV. We study several models, as well as a general effective field theory, and determine the parameter space which provides the best simultaneous fit to the CDF asymmetry, the Tevatron top pair production cross section, and the exclusion regions from LHC dijet resonance and contact interaction searches. Flavor constraints on these models are more subtle and less severe than the literature indicates. We find a large region of allowed parameter space at high axigluon mass and a smaller region at low mass; we match the latter to an SU(3)xSU(3)/SU(3) coset model with a heavy vector-like fermion. Our scenario produces discoverable effects at the LHC with only 1-2 inverse femtobarns of luminosity at 7-8 TeV. Lastly, we point out that a Tevatron measurement of the b-quark forward-backward asymmetry would be very helpful in characterizing the physics underlying the top-quark asymmetry.Comment: 35 pages, 10 figures, 4 table

Improving the lake scheme within a coupled WRF‐lake model in the Laurentian Great Lakes

In this study, a one‐dimensional (1‐D) thermal diffusion lake model within the Weather Research and Forecasting (WRF) model was investigated for the Laurentian Great Lakes. In the default 10‐layer lake model, the albedos of water and ice are specified with constant values, 0.08 and 0.6, respectively, ignoring shortwave partitioning and zenith angle, ice melting, and snow effect. Some modifications, including a dynamic lake surface albedo, tuned vertical diffusivities, and a sophisticated treatment of snow cover over lake ice, have been added to the lake model. A set of comparison experiments have been carried out to evaluate the performances of different lake schemes in the coupled WRF‐lake modeling system. Results show that the 1‐D lake model is able to capture the seasonal variability of lake surface temperature (LST) and lake ice coverage (LIC). However, it produces an early warming and quick cooling of LST in deep lakes, and excessive and early persistent LIC in all lakes. Increasing vertical diffusivity can reduce the bias in the 1‐D lake but only in a limited way. After incorporating a sophisticated treatment of lake surface albedo, the new lake model produces a more reasonable LST and LIC than the default lake model, indicating that the processes of ice melting and snow accumulation are important to simulate lake ice in the Great Lakes. Even though substantial efforts have been devoted to improving the 1‐D lake model, it still remains considerably challenging to adequately capture the full dynamics and thermodynamics in deep lakes.Key PointsA dynamic lake surface albedo scheme is added to the lake modelThe new lake model produces a more reasonable LST and LIC than the default lake modelIce melting and snow accumulation are important to simulating lake ice in the Great LakesPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135995/1/jame20346_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/135995/2/jame20346.pd

Comparison of the calculations of the stability properties of a specific stellarator equilibrium with different MHD stability codes

A particular configuration of the LHD stellarator with an unusually flat pressure profile has been chosen to be a test case for comparison of the MHD stability property predictions of different three-dimensional and averaged codes for the purpose of code comparison and validation. In particular, two relatively localized instabilities, the fastest growing modes with toroidal mode number n = 2 and n = 3 were studied using several different codes, with the good agreement that has been found providing justification for the use of any of them for equilibria of the type considered

Diagnosis and rational treatment of painful diabetic peripheral neuropathy: an interdisciplinary expert consensus

Diabetic peripheral neuropathy is a common chronic complication of diabetes mellitus, significantly impairing well-being, quality of life and functioning of patients. The prevalence of diabetic peripheral neuropathy in the Russian Federation ranges from 0.1% to 67.2% in type 1 and from 0.1 to 42.4% in type 2 diabetes mellitus. However, based on the large-scale epidemiological studies, the true prevalence of diabetic peripheral neuropathy is much higher (50 to 70%), with its painful variant occurring in 16% to 30% of patients. Despite the fact that diabetic peripheral neuropathy remains the most common chronic complication of diabetes mellitus, its diagnosis and therapy leave much to be desired. To optimize diagnostic and treatment approaches to painful diabetic peripheral neuropathy, a group of experts representing the leading Russian professional medical associations has developed clinical guidelines for the diagnosis and rational therapy of patients with painful diabetic peripheral neuropathy. This document presents practical aspects of the clinical diagnosis of painful diabetic peripheral neuropathy and an algorithm for differential diagnosis of pain in the lower extremities in patients with diabetes mellitus. The use of symptomatic analgesics with central action, such as anticonvulsants, antidepressants and opioids, is based on the main aspects of neuropathic pain pathophysiology. The characteristics of each drug class are given, with consideration of evidence on their efficacy, tolerability, and the possibility of combination therapy. The data on the first, second, and third lines of agents is presented in accordance with several international clinical guidelines. The need for a tailored drug choice, taking into account the evidence-based data on their efficacy and safety, concomitant drug therapy, tolerability, cost and preferences of the patient, age of the patient and concomitant disorders, is emphasized

Conservative Therapy of Pressure Ulcers Using Physical Methods (Review)

In Russia and European countries, the incidence of pressure (decubitus) ulcers in sedentary patients with severe comorbidities, spinal trauma, and cerebral accident sequelae varies from 3 to 40 %, reaching 80 % in the chronic critical illness. The final result of conservative treatment of pressure ulcers (PU) with adequate correction of comorbidities and proper care of the immobilized patient depends largely on the choice of local interventions.   Aim of the review: to demonstrate the range of effective methods of physical treatment of pressure ulcers suitable for conservative treatment.   Materials and methods. We selected and analyzed 80 scientific publications. Sources were selected from the PubMed, Scopus, and RSCI databases of medical and biological publications. The following methods were covered: negative pressure wound therapy, ultrasonic methods, hydrosurgical treatment, plasma flows, laser therapy (including low-level laser therapy), «hardware» acceleration of regenerative processes, including electrical stimulation, as well as a combination of these methods.   Results. The variety of physical methods of wound treatment, on the one hand, provides an opportunity to select an individual therapy program. On the other hand, each method has its own limitations and contraindications. That is why in practice various combinations of these methods are reasonable.   Conclusion. For several objective reasons, no reduction of PU incidence in clinical practice is expected. Therefore, studying the issues of evidence-based clinical effectiveness and economic feasibility of various conservative techniques of decubitus treatment to find best solutions in this area is warranted

Optical Properties and Upconversion Luminescence of BaTiO3 Xerogel Structures Doped with Erbium and Ytterbium

Erbium upconversion (UC) photoluminescence (PL) from sol-gel derived barium titanate (BaTiO3:Er) xerogel structures fabricated on silicon, glass or fused silica substrates has been studied. The fabricated structures under continuous-wave excitation at 980 nm and nanosecond laser excitation at 980 and 1540 nm demonstrate room temperature PL with the bands at 410, 523, 546, 658, 800 and 830 nm, which correspond to the 2H9/2 → 4I15/2, 2H11/2 → 4I15/2, 4S3/2 → 4I15/2, 4F9/2→ 4I15/2 and 4I9/2→ 4I15/2 transitions in Er3+ ions. The intensity of erbium UС PL increases when an additional macroporous layer of strontium titanate is used beneath the BaTiO3 xerogel layer. It is enhanced for BaTiO3 xerogel films codoped with erbium and ytterbium (BaTiO3:Er,Yb). The redistribution of the intensity of the PL bands is observed for the latter and it depends on the excitation conditions. Finally, a Bragg reflector and a microcavity structure comprising of alternating (BaTiO3:Er,Yb) and SiO2 xerogel layers were fabricated with the cavity mode near the red PL band of Er3+ ions. Enhancement of UC PL from the microcavity was observed for the sample annealed from 450°C to 600°C. The fabricated cavity structures annealed at 450°C allow us to tune the cavity mode with 10 nm shift within the temperature range from +20°C to +130°C. Photonic application of BaTiO3 xerogel structures doped with lanthanides is discussed