A gyrokinetic model for the plasma periphery of tokamak devices

A gyrokinetic model is presented that can properly describe strong flows, large and small amplitude electromagnetic fluctuations occurring on scale lengths ranging from the electron Larmor radius to the equilibrium perpendicular pressure gradient scale length, and large deviations from thermal equilibrium. The formulation of the gyrokinetic model is based on a second order description of the single charged particle dynamics, derived from Lie perturbation theory, where the fast particle gyromotion is decoupled from the slow drifts, assuming that the ratio of the ion sound Larmor radius to the perpendicular equilibrium pressure scale length is small. The collective behavior of the plasma is obtained by a gyrokinetic Boltzmann equation that describes the evolution of the gyroaveraged distribution function and includes a non-linear gyrokinetic Dougherty collision operator. The gyrokinetic model is then developed into a set of coupled fluid equations referred to as the gyrokinetic moment hierarchy. To obtain this hierarchy, the gyroaveraged distribution function is expanded onto a velocity-space Hermite-Laguerre polynomial basis and the gyrokinetic equation is projected onto the same basis, obtaining the spatial and temporal evolution of the Hermite-Laguerre expansion coefficients. The Hermite-Laguerre projection is performed accurately at arbitrary perpendicular wavenumber values. Finally, the self-consistent evolution of the electromagnetic fields is described by a set of gyrokinetic Maxwell's equations derived from a variational principle, with the velocity integrals of the gyroaveraged distribution function explicitly evaluated

Zapotec and Mixe use of Tropical Habitats for securing medicinal plants in MéXico

Medicinal plants are essential in the medical systems of the Mixe and Zapotec. In this study ethno-ecological strategies, employed by the two neighboring Indian groups in Mexico, for obtaining medicinal plants are analyzed. The indigenous classification of the environment is notably different from the Western one and distinguishes six dissimilar principal "zones” or land use types. Most ethnomedically important species are cultivated in the "house garden” or gathered in the community or its immediate surroundings. The house garden, for example, contributes 31.8% and 26.2% of all medical taxa for the Mixe and Zapotec, respectively. These ethnobotanical data on the indigenous uses indicate that anthropogenic types of vegetation yield the largest percentage of medicinal tax

Non-unique factorization of polynomials over residue class rings of the integers

We investigate non-unique factorization of polynomials in Z_{p^n}[x] into irreducibles. As a Noetherian ring whose zero-divisors are contained in the Jacobson radical, Z_{p^n}[x] is atomic. We reduce the question of factoring arbitrary non-zero polynomials into irreducibles to the problem of factoring monic polynomials into monic irreducibles. The multiplicative monoid of monic polynomials of Z_{p^n}[x] is a direct sum of monoids corresponding to irreducible polynomials in Z_p[x], and we show that each of these monoids has infinite elasticity. Moreover, for every positive integer m, there exists in each of these monoids a product of 2 irreducibles that can also be represented as a product of m irreducibles.Comment: 11 page

Analysis and correction of the magnetic field effects in the Hybrid Photo-Detectors of the RICH2 Ring Imaging Cherenkov detector of LHCb

The Ring Imaging Cherenkov detectors of the LHCb experiment at the Large Hadron Collider at CERN are equipped with Hybrid Photo-Detectors. These vacuum photo-detectors are affected by the stray magnetic field of the LHCb magnet, which degrades their imaging properties. This effect increases the error on the Cherenkov angle measurement and would reduce the particle identification capabilities of LHCb. A system has been developed for the RICH2 Ring Imaging Cherenkov detector to perform a detailed characterisation of the magnetic distortion effects. It is described, along with the methods implemented to correct for these effects, restoring the optimal resolution.Comment: 16 pages, 11 figure

Lack of Leukocyte Migration Inhibition by Hepatitis B Antigen and Normal Nonspecific Immunoreactivity in Asymptomatic Carriers

The immune response to hepatitis B surface antigen (RBs Ag) was studied in 25 asymptomatic carriers by the leukocyte migration-inhibition (LMI) test in agarose. In the presence of purified RBs Ag, inhibition was demonstrated in only four of 25 carriers, in contrast to 24 of 28 patients who cleared the antigen after acute infection with hepatitis B. Tuberculin purified protein derivative (PPD) was also used as an antigen for the LMI test in these carriers. Inhibition was demonstrated in only 12 of 25 individuals who had positive PPD skin tests, in contrast to all of 14 normal noncarrier individuals with positive PPD skin tests and none of 12 normal noncarrier individuals with negative PPD skin tests. A nonspecific immunological investigation of the asymptomatic carriers gave normal results. The lack of an immune response to HBs Ag was thought to be responsible for the persistence of the antigen and also for the absence of symptom

The confined-deconfined interface tension, wetting, and the spectrum of the transfer matrix

The reduced tension $\sigma_{cd}$ of the interface between the confined and the deconfined phase of $SU(3)$ pure gauge theory is determined from numerical simulations of the first transfer matrix eigenvalues. At $T_c = 1/L_t$ we find $\sigma_{cd} = 0.139(4) T_c^2$ for $L_t = 2$. The interfaces show universal behavior because the deconfined-deconfined interfaces are completely wet by the confined phase. The critical exponents of complete wetting follow from the analytic interface solutions of a $\Z(3)$-symmetric $\Phi^4$ model in three dimensions. We find numerical evidence that the confined-deconfined interface is rough.Comment: Talk presented at the International Conference on Lattice Field Theory, Lattice 92, to be published in the proceedings, 4 pages, 4 figures, figures 2,3,4 appended as postscript files, figure 1 not available as a postscript file but identical with figure 2 of Nucl. Phys. B372 (1992) 703, special style file espcrc2.sty required (available from hep-lat), BUTP-92/4

Evaluation of propofol for repeated prolonged deep sedation in children undergoing proton radiation therapy

Background The aim of this study is to evaluate the safety and sufficiency of a fixed dose rate propofol infusion for repeated prolonged deep sedation in children for proton radiation therapy (PRT). Methods With ERB approval, we recorded anaesthesia monitoring data in children undergoing repeated prolonged propofol sedation for PRT. Sedation was introduced with a single bolus of i.v. midazolam 0.1 mg kg−1 followed by repeated small boluses of propofol until sufficient depth of sedation was obtained. Sedation was maintained with fixed dose rate propofol infusion of 10 mg kg−1 h−1 in all patients up to the end of the radiation procedure. Patient characteristics, number and duration of sedation, propofol induction dose, necessity to alter propofol infusion rate, and heart rate, mean arterial pressure, respiratory rate were noted at the end of the radiation procedure before cessation of the propofol infusion. Data are mean (sd) or range (median) as appropriate. Results Eighteen children aged from 1.4 to 4.2 yr (2.6 yr) had 27.6 (sd 2.0) (497 in total) radiation procedures within 44.1 (4.0) days lasting 55.7 (8.8) min. Propofol bolus dose for induction, monitoring, and positioning was 3.7 (1.0) mg kg−1. Propofol bolus requirements were quite stable over the successive weeks of treatment and variability was larger between individuals than over time. In none of the children did propofol infusion rate need to be changed from the pre-set 10 mg kg−1 h−1 flow rate because of haemodynamic state, respiratory conditions or inadequate anaesthesia. Conclusions Repeated prolonged deep sedation over several weeks in very young children using a fixed rate propofol infusion was safe and adequate for all patient

Erhöhte Trockenstresstoleranz von Kleegras nach reduzierter Bodenbearbeitung

Grass-clover leys are an integral part of organic rotations. We performed an experiment with reduced tillage (RT) and conventional tillage (CT) using mouldboard ploughing in a rotation in Frick (Switzerland) on a heavy soil and 1000 mm mean annual precipitation. The grass-clover mixture was sawn in autumn 2005 after uniform seed bed preparation with a rotary hoe in both tillage systems without ploughing. After emergence most of the clover seedlings collapsed in the CT plots due to draught, while they survived in the RT plots. This led to a much higher share of clover in the mixture under RT. Grass-clover yields were 29 and 23% higher in RT than in CT plots in the first and second year of cultivation in 2006 and 2007, respectively. Grass grown in RT plots was higher in nitrogen (N), phosphorous (P), potassium (K) and magnesium (Mg) content than in CT plots; clover contained solely more P in RT plots. Over all grass-clover had better growing conditions in RT compared to CT plots in our experiment, reflecting after-effects of the differentiated tillage schemes applied for the preceding arable crops. It is suggested that reduced tillage has a high potential to improve water stress tolerance of cropping systems

Improved serodiagnosis of alveolar echinococcosis of humans using an in vitro-produced Echinococcus multilocularis antigen

Serology is an important tool for the diagnosis of alveolar echinococcosis (AE) in humans. In order to improve serodiagnostic performance, we have developed an in vitro-produced Echinococcus mulilocularis metacestode vesicle fluid (EmVF) antigen for application in an immunoblot assay. Immunoblot analysis of EmVF revealed an abundant immunoreactive band triplet of 20-22kDa, achieving a sensitivity of 100% based on the testing of sera from 62 pre-operative and pre-treatment cases of active and inactive AE. Thus, the EmVF-immunoblotting allowed the specific detection of cases seronegative by the Em2- and/or EmII/3-10-ELISA, usually attributable to abortive, inactive cases of AE. The specificity of the EmVF-immunoblotting did not allow discrimination between AE and cystic echinococcosis (CE) but was 100% with respect to non-Echinococcus parasitic infections or cancer malignancies. Based on the findings of this study, it is recommended that the current ELISA test combination (Em2- and II/3-10-ELISA) be complemented with EmVF-immunoblotting, allowing an improved diagnosis of both clinical and subclinical forms of AE, including those associated with E. multilocularis-specific antibody reactivities not detectable by ELIS