Snow metamorphism: a fractal approach

Snow is a porous disordered medium consisting of air and three water phases: ice, vapour and liquid. The ice phase consists of an assemblage of grains, ice matrix, initially arranged over a random load bearing skeleton. The quantitative relationship between density and morphological characteristics of different snow microstructures is still an open issue. In this work, a three-dimensional fractal description of density corresponding to different snow microstructure is put forward. First, snow density is simulated in terms of a generalized Menger sponge model. Then, a fully three-dimensional compact stochastic fractal model is adopted. The latter approach yields a quantitative map of the randomness of the snow texture, which is described as a three-dimensional fractional Brownian field with the Hurst exponent H varying as continuous parameter. The Hurst exponent is found to be strongly dependent on snow morphology and density. The approach might be applied to all those cases where the morphological evolution of snow cover or ice sheets should be conveniently described at a quantitative level

Reproduction and population structure of the sea cucumber Holothuria tubulosa in the Dardanelles Strait, Turkey

In this study, Holothuria tubulosa Gmelin 1791 was investigated from April 2013 to March 2014 in the Dardanelles Strait, to outline the morphological characteristics, reproductive patterns and the relationship between population characteristics and environmental parameters. Between 15 and 30 individuals of this species were sampled monthly from three stations. There was a negative allometry between length and weight, being gutted weight the most reliable measurement for this species. Reproductive patterns of the species were identified the first time for Turkish coasts. By macroscopic examination of the gonads, smallest sizes (gutted length) were measured as 8.4 and 8.1 cm for female and male, respectively. Sex ratio was calculated as 1: 1.1 with differences between seasons. The reproduction of sea cucumbers occurred between August and September after Gonadosomatic Index (GSI) values reached their maximum in July. The species was found down to 10 m depth with a population density of 0.21 / m2, which was rather low compared to previously reported values for Mediterranean populations of this species. There was a high positive correlation between population density and GSI of the species. The highest population density was observed where the largest sea grass meadows are found

Transversity and Collins functions from SIDIS and e+e- data

A global analysis of the experimental data on azimuthal asymmetries in semi-inclusive deep inelastic scattering (SIDIS), from the HERMES and COMPASS Collaborations, and in e+e- --> h1 h2 X processes, from the BELLE Collaboration, is performed. It results in the extraction of the Collins fragmentation function and, for the first time, of the transversity distribution function for u and d quarks. These turn out to have opposite signs and to be sizably smaller than their positivity bounds. Predictions for the azimuthal asymmetry A_{UT}^{sin(phi_h + phi_S)}, as will soon be measured at JLab and COMPASS operating on a transversely polarized proton target, are then presented

Numerical investigation of the polymer melt flow in injection molding by using ILU preconditioned GMRES

The implementation of a modern preconditioned Newton‐Krylov solvers to the polymer melt flow in injection molding is the main focus of this paper. The viscoelastic and non‐isothermal characteristics of the transient polymer flow is simulated numerically and the highly non‐linear problem solved. This non‐linear behavior results from the combination of the dominant convective terms and the dependence of the polymer viscosity to the changing temperature and the shear rate. The governing non‐Newtonian fluid flow and energy equations with appropriate approximations are discretized by finite differencing. Elliptic Grid Generation technique is used to map physical domain to computational domain. The resulting non‐linear system is solved by using Newton's method. GMRES, one of the Krylov subspace methods, used as an iterative algorithm in order to solve the linear system at each non‐linear step. Incomplete LU preconditioner is used for better convergence. Numerical solution of polymer flow is presented to demonstrate that these methods are efficient and robust for solving such flow problems. Polimerinio lydinio tekėjimo skaitinė analizė panaudojant GMRES metodą su ilu sąlygotumą gerinančia matrica Santrauka Šiame darbe nagrinejamas šiuolaikiniu Niutono‐Krylovo metodu efektyvumas, kai jais sprendžiame polimerinio lydinio tekejimo uždavini. Uždavinys yra stipriai netiesinis, tai salygoja vyraujančiu konvekciniu nariu saveika ir koeficientu priklausomybe nuo temperatūros. Uždavinys aproksimuojamas baigtiniu skirtumu schema. Panaudojant elipsini tinklo generatoriu fizine skaičiavimo sritis yra atvaizduojama i skaičiavimo sriti. Gautoji netiesiniu lygčiu sistema sprendžiama Niutono metodu. Kiekviename iteraciniame žingsnyje tiesiniu lygčiu sistema sprendžiama GMRES metodu, kuris modifikuojamas nepilnos LU faktoriza‐cijos neišreikštiniu operatoriumi. Pateiktieji skaičiavimo eksperimento rezultatai iliustruoja algoritmu efektyvuma ir universaluma. First Published Online: 14 Oct 201

Current clinician perspective on non-vitamin K antagonist oral anticoagulant use in challenging clinical cases.

OBJECTIVE: The evolution of non-vitamin K antagonist anticoagulants (NOACs) has changed the horizon of stroke prevention in atrial fibrillation (SPAF). All 4 NOACs have been tested against dose-adjusted warfarin in well-designed, pivotal, phase III, randomized, controlled trials (RCTs) and were approved by regulatory authorities for an SPAF indication. However, as traditional RCTs, these trials have important weaknesses, largely related to their complex structure and patient participation, which was limited by strict inclusion and extensive exclusion criteria. In the real world, however, clinicians are often faced with complex, multimorbid patients who are underrepresented in these RCTs. This article is based on a meeting report authored by 12 scientists studying atrial fibrillation (AF) in diverse ways who discussed the management of challenging AF cases that are underrepresented in pivotal NOAC trials. METHODS: An advisory board panel was convened to confer on management strategies for challenging AF cases. The article is derived from a summary of case presentations and the collaborative discussions at the meeting. CONCLUSION: This expert consensus of cardiologists aimed to define management strategies for challenging cases with patients who underrepresented in pivotal trials using case examples from their routine practice. Although strong evidence is lacking, exploratory subgroup analysis of phase III pivotal trials partially informs the management of these patients. Clinical trials with higher external validity are needed to clarify areas of uncertainty. The lack of clear evidence about complex AF cases has pushed clinicians to manage patients based on clinical experience, including rare situations of off-label prescriptions

Assessment of Austrian contribution toward EU 2020 target sharing: Responding to the energy and climate package of the European Commission

The overarching implications of the EU 2020 targets for Austria call for a fundamental restructuring of the Austrian energy sector towards increased energy efficiency. Two guiding principles for this restructuring are required in order to be compatible with the targets for greenhouse gas emissions and renewables (RES) expected for Austria: final energy consumption needs to be stabilised at the levels of 2005; renewable energy sources need to be expanded at least by 40 percent. For the final negotiations on phase 3 of the EU Emissions Trading System we propose contributions on three issues: 1. operational procedures for dealing with carbon leakage and competitiveness in all sectors that provide criteria for allocating free allowances: 2. empowering the carbon market by extending the task of the emissions allowances issuing carbon authority to control the liquidity of the carbon market in view of stabilising the carbon price; 3. designing the auctioning mechanism by considering timing and auctioning as a strategic instrument for enhancing the carbon market and considering unified auc-tioning with revenues split among EU countries. Similarly we suggest for the final negotiations on the RES Directive improvements that overcome discrepancies between national RES targets and available resources for implementation. This requires in particular improved cooperation between EU countries for a better mapping of targets and potentials

Semi-Inclusive Deep Inelastic Scattering processes from small to large P_T

We consider the azimuthal and $P_T$ dependence of hadrons produced in unpolarized Semi-Inclusive Deep Inelastic Scattering (SIDIS) processes, within the factorized QCD parton model. It is shown that at small $P_T$ values, P_T \lsim 1 GeV/c, lowest order contributions, coupled to unintegrated (Transverse Momentum Dependent) quark distribution and fragmentation functions, describe all data. At larger $P_T$ values, P_T \gsim 1 GeV/c, the usual pQCD higher order collinear contributions dominate. Having explained the full $P_T$ range of available data, we give new detailed predictions concerning the azimuthal and $P_T$ dependence of hadrons which could be measured in ongoing or planned experiments by HERMES, COMPASS and JLab collaborations.Comment: 14 pages, 17 figures, uses revtex

The protective effects of melatonin and vitamin E on antioxidant enzyme activities and epididymal sperm characteristics of homocysteine treated male rats

The aims of this study were to investigate the effects of homocysteine (Hcy) on epididymal sperm characteristics, plasma testosterone level and biochemical changes related to oxidative stress and to examine the effects of melatonin (Mlt) or Vitamin E (VE) administration on these parameters in Hcy-treated male rats. In this study, 32 adult male albino rats of Wistar strain were used. The rats were randomly divided into four groups. The first group of rats received only Hcy (0.71 mg/kg/day) intraperitonially (ip) for 6 weeks. The second group of rats was given Hcy along with simultaneous administration of Mlt (1 mg/kg/day) subcutaneously. The third group of rats received Hcy along with simultaneous administration of VE (125 mg/kg/day, ip). The fourth group of rats served as control during 6 weeks and was daily given 0.1mL of physiological saline (NaCl, 0.9%) ip. While the plasma malondialdehyde level significantly (p < 0.05) increased, the plasma superoxide dismutase, glutathione peroxidase and catalase activities significantly (p < 0.05) decreased in Hcy-treated rats when compared to control rats. Furthermore, the epididymal sperm concentration, the percentage of progressive sperm motility and plasma testosterone level were significantly (p < 0.05) lower in Hcy-treated rats than those of the control rats. The simultaneous administration of Mlt or VE to Hcy-treated animals impeded the decrease in the plasma antioxidant enzyme activities, testosterone level, the epididymal sperm concentration and motility. In conclusion, this study indicates that chronic administration of Hcy has the harmful effect on the epididymal sperm characteristics of male rats. The administration of Mlt or VE can prevent adverse effects of Hcy on the plasma antioxidant enzyme activities, testosterone level, epididymal sperm count and motility in male rats

Geo-Biological Investigations on Azooxanthellate Cold-Water Coral Reefs on the Carbonate Mounds Along the Celtic Continental Slope

Northeast Atlantic 2004 Cruise No. 61, Leg 1 April 19 to May 4, 2004, Lisbon – Cor

Lycopene and ellagic acid prevent testicular apoptosis induced by cisplatin

The aim of this studywasto investigate the possible protective effects of lycopene (LC) and ellagic acid (EA) on cisplatin (CP)-induced testicular apoptosis in male rats. The control group was treated with placebo; LC, EA and CP groups were given alone LC, EA and CP, respectively; the CP + LC group was treated with a combination of CP and LC; and the CP + EAgroup was treated with a combination of CP and EA. Although CP significantly increased the number of Bax-positive (apoptotic) cells it had no effect on the number of Bcl- 2-positive (antiapoptotic) cells compared with the control group. Administration of CP caused significant increase in lipid peroxidation and nonsignificant decrease in superoxide dismutase (SOD) activity along with some histopathological lesions in testicular tissue. However, combined treatments of LC or EA in addition to CP tended to prevent the CP-induced testicular apoptosis, histopathological lesions and lipid peroxidation