Electrostatic potential in a superconductor

The electrostatic potential in a superconductor is studied. To this end Bardeen's extension of the Ginzburg-Landau theory to low temperatures is used to derive three Ginzburg-Landau equations - the Maxwell equation for the vector potential, the Schroedinger equation for the wave function and the Poisson equation for the electrostatic potential. The electrostatic and the thermodynamic potential compensate each other to a great extent resulting into an effective potential acting on the superconducting condensate. For the Abrikosov vortex lattice in Niobium, numerical solutions are presented and the different contributions to the electrostatic potential and the related charge distribution are discussed.Comment: 19 pages, 11 figure

G-quadruplex recognition activities of <it>E. Coli</it> MutS

<p>Abstract</p> <p>Background</p> <p>Guanine quadruplex (G4 DNA) is a four-stranded structure that contributes to genome instability and site-specific recombination. G4 DNA folds from sequences containing tandemly repetitive guanines, sequence motifs that are found throughout prokaryote and eukaryote genomes. While some cellular activities have been identified with binding or processing G4 DNA, the factors and pathways governing G4 DNA metabolism are largely undefined. Highly conserved mismatch repair factors have emerged as potential G4-responding complexes because, in addition to initiating heteroduplex correction, the human homologs bind non-B form DNA with high affinity. Moreover, the MutS homologs across species have the capacity to recognize a diverse range of DNA pairing variations and damage, suggesting a conserved ability to bind non-B form DNA.</p> <p>Results</p> <p>Here, we asked if <it>E. coli</it> MutS and a heteroduplex recognition mutant, MutS F36A, were capable of recognizing and responding to G4 DNA structures. We find by mobility shift assay that <it>E. coli</it> MutS binds to G4 DNA with high affinity better than binding to G-T heteroduplexes. In the same assay, MutS F36A failed to recognize G-T mismatched oligonucleotides, as expected, but retained an ability to bind to G4 DNA. Association with G4 DNA by MutS is not likely to activate the mismatch repair pathway because nucleotide binding did not promote release of MutS or MutS F36A from G4 DNA as it does for heteroduplexes. G4 recognition activities occur under physiological conditions, and we find that M13 phage harboring G4-capable DNA poorly infected a MutS deficient strain of <it>E. coli</it> compared to M13mp18, suggesting functional roles for mismatch repair factors in the cellular response to unstable genomic elements.</p> <p>Conclusions</p> <p>Taken together, our findings demonstrate that <it>E. coli</it> MutS has a binding activity specific for non-B form G4 DNA, but such binding appears independent of canonical heteroduplex repair activation.</p

Biopsychosocial outcomes in individuals with and without spinal cord injury: a Swiss comparative study

STUDY DESIGN: Multicentre controlled study. OBJECTIVES: To investigate if individuals with and without spinal cord injury (SCI) differ in biopsychosocial variables according to the International Classification of Functioning, Disability and Health (ICF). SETTING: Participants were recruited through three major SCI rehabilitation centres in Switzerland. METHODS: A convenience sample of people with SCI (N=102) and a matched non-SCI sample (N=73) were compared according to secondary conditions, pain, depressive symptoms, participation, social support, self-efficacy, self-esteem, coping and sense of coherence. Difference tests and multivariate logistic regression analyses to predict the likelihood of group membership were calculated. RESULTS: People with SCI reported more health conditions, higher levels of anxiety and depressive symptoms, worse pain and pain interference, lower level of participation and social support, lower self-efficacy, self-esteem and task- and emotion-oriented coping. The two samples did not differ in satisfaction with social support, in use of avoidance-oriented coping and in sense of coherence. Health conditions, pain interference, participation and age were found to be significant predictors of the likelihood of group membership. In the logistic regression models, the number of health conditions, limitations due to health conditions, pain interference, participation, task-oriented coping and age are significant predictors of group membership, accounting for 55% of variation. CONCLUSION: Health conditions, pain interference and participation seemed to be the areas of biopsychosocial functioning that are substantially influenced by SCI. Potential buffering resources seem to be diminished in individuals with SCI. In rehabilitation practice, prevention of secondary conditions, treatment of pain, enhancement of participation and strengthening resources should be addressed