Transverse target-spin asymmetry in exclusive electroproduction of Po mesons

Steenhoven, G. van der [Promotor]Blok, H.P. [Copromotor

Effective Lagrangians for BCS Superconductors at T=0

We show that the low frequency, long wavelength dynamics of the phase of the pair field for a BCS-type s-wave superconductor at T=0 is equivalent to that of a time-dependent non-linear Schr\"odinger Lagrangian (TDNLSL), when terms required by Galilean invariance are included. If the modulus of the pair field is also allowed to vary, the system is equivalent to two coupled TDNLSL's. We also refer the interested reader to our earlier paper, `Nonlinear Schrodinger equation for superconductors' [cond-mat/9312099], for a different line of derivationComment: Latex, 13 page

Livelihood diversification and the expansion of artisanal mining in rural Tanzania: drivers and policy implications

This paper provides an extended analysis of livelihood diversification in rural Tanzania, with special emphasis on artisanal and small-scale mining (ASM). Over the past decade, this sector of industry, which is labour-intensive and comprises an array of rudimentary and semi-mechanized operations, has become an indispensable economic activity throughout Sub-Saharan Africa, providing employment to a host of redundant public sector workers, retrenched large-scale mine labourers and poor farmers. In many of the region’s rural areas, it is overtaking subsistence agriculture as the primary industry. Such a pattern appears to be unfolding within the Morogoro and Mbeya regions of southern Tanzania, where findings from recent research suggest that a growing number of smallholder farmers are turning to ASM for employment and financial support. It is imperative that national rural development programmes take this trend into account and provide support to these people

Dexamethasone and long-term outcome in adults with bacterial meningitis

This follow-up study of the European Dexamethasone Study was designed to examine the potential harmful effect of adjunctive dexamethasone treatment on long-term neuropsychological outcome in adults with bacterial meningitis. METHODS: Neurological, audiological, and neuropsychological examinations were performed in adults who survived pneumococcal or meningococcal meningitis. RESULTS: Eighty-seven of 99 (88%) eligible patients were included in the follow-up study; 46 (53%) were treated with dexamethasone and 41 (47%) with placebo. Median time between meningitis and testing was 99 months. Neuropsychological evaluation showed no significant differences between patients treated with dexamethasone and placebo. The proportions of patients with persisting neurological sequelae or hearing loss were similar in the dexamethasone and placebo groups. The overall rate of cognitive dysfunction did not differ significantly between patients and control subjects; however, patients after pneumococcal meningitis had a higher rate of cognitive dysfunction (21 vs 6%; p = 0.05) and experienced more impairment of everyday functioning due to physical problems (p = 0.05) than those after meningococcal meningitis. INTERPRETATION: Treatment with adjunctive dexamethasone is not associated with an increased risk for long-term cognitive impairment. Adults who survive pneumococcal meningitis are at significant risk for long-term neuropsychological abnormalities

Dynamics of quantum quenching for BCS-BEC systems in the shallow BEC regime

The problem of coupled Fermi-Bose mixtures of an ultracold gas near a narrow Feshbach resonance is approached through the time-dependent and complex Ginzburg-Landau (TDGL) theory. The dynamical system is constructed using Ginzburg-Landau-Abrikosov-Gor'kov (GLAG) path integral methods with the single mode approximation for the composite Bosons, and the equilibrium states are obtained in the BEC regime for adiabatic variations of the Feshbach detuning along the stationary solutions of the dynamical system. Investigations into the rich superfluid dynamics of this system in the shallow BEC regime yields the onset of multiple interference patterns in the dynamics as the system is quenched from the deep-BEC regime. This results in a partial collapse and revival of the coherent matter wave field of the BEC, whose temporal profile is reported.Comment: 24 pages, 7 figures. Submitted to European Journal of Physics Plu

BCS to Bose Crossover in Anisotropic Superconductors

In this work we use functional integral techniques to examine the nearest neighbour attractive Hubbard model on a quasi-2D lattice. It is a simple phenomenological model for the high-Tc cuprates that allows both extended (non-local) s- and d-wave singlet superconductivity as well as mixed symmetry states. The Hartree-Gor'kov mean field theory of the model has a finite temperature phase diagram which shows a transition from pure s-wave to pure d-wave superconductivity, via a mixed symmetry s+id state, as a function of doping. Including Gaussian fluctuations we examine the crossover from weak-coupling BCS superconductivity to the strong-coupling Bose-Einstein condensation of composite s- or d-wave bosons and comment on the origin and symmetry of the pseudogap.Comment: 20 pages inc. 13 figure

Comparison of Training, Anthropometric, Physiological and Psychological Variables of Ultra-Endurance Cyclists and Runners

AbstractWe compared training, anthropometric, physiological and psychological characteristics between 14 cyclists, participants in a 24-hour mountain bike race and 12 runners, participants in a 7-day running ultra-marathon. Methods: Questionnaires and physiological measurements. Results: The differences in ages between cyclists and runners were significant (p << 0.01). The pre-race minus post-race differences (Δ) in body mass (from 76.5 ± 13.1kg to 72.0 ± 12.0kg) and (Δ) in value of hematocrit (6.1 ± 3.5%) were significant only in runners. The post-race minus pre-race difference (Δ) in the rating of perceived exertion was significant in both groups

Comparison of speech intelligibility in quiet and in noise after hearing aid fitting according to a purely prescriptive and a comparative fitting procedure

We compared two different types of hearing-aid fitting procedures in a double-blind randomized clinical study. Hearing aid fittings based on a purely prescriptive procedure (the NAL-RP formula) were compared to a comparative fitting procedure based on optimizing speech intelligibility scores. Main outcome measures were improvement of speech intelligibility scores in quiet and in noise. Data were related to the real-ear insertion responses that were measured after fitting. For analysis purposes subgroups were composed according to degree of hearing loss, characterized by unaided speech intelligibility in quiet, previous experience with hearing aids, unilateral or bilateral fittings and type of hearing aid. We found equal improvement of speech intelligibility in quiet, while fitting according to the prescriptive formula resulted in a somewhat better performance as expressed by the speech-to-noise ratio in comparison to the comparative procedure. Both procedures resulted in comparable real-ear insertion responses