Disorder driven destruction of a phase transition in a superconductor

We investigate the effects of disorder on a layered superconductor. The clean system is known to have a first order phase transition which is clearly identified by a sharp peak in the specific heat. The peak is lost abruptly as the strength of the disorder is increased. Hence, for strong disorder there is no phase transition as a function of temperature but merely a crossover which is still detectable in the IV characteristic.Comment: 3 pages REVTeX , 5 figure

Har Ager-Svinemælk og Ager-Tidsel skudhvile?

Rodukrudt er et stigende og udbredt problem i specielt økologisk jordbrug inden for de nordiske lande, hvor specielt arterne Ager-Tidsel og Ager-Svinemælk optræder som problemukrudt. For at kunne udføre en effektiv bekæmpelse, er det nødvendigt at kende de faktorer som bestemmer om planterne er i hvile

Pea-barley intercrop N dynamics in farmers fields

Knowledge about crop performances in farmers’ fields provides a link between on-farm practice and re-search. Thereby scientists may improve their ability to understand and suggest solutions for the problems facing those who have the responsibility of making sound agricultural decisions. Nitrogen (N) availability is known to be highly heterogeneous in terrestrial plant communities (Stevenson and van Kessel, 1997), a heterogeneity that in natural systems is often associated with variation in the distri-bution of plant species. In intercropping systems the relative proportion of component crops is influenced by the distribution of growth factors such as N in both time and space (Jensen, 1996). In pea-barley intercrops, an increase in the N supply promotes the growth of barley thereby decreasing the N accumulation of pea and giving rise to changes in the relative proportions of the intercropped components (Jensen, 1996). The pres-sure of weeds may, however, significantly change the dynamics in intercrops (Hauggaard-Nielsen et al., 2001). Data from farmers’ fields may provide direct, spatially explicit information for evaluating the poten-tials of improving the utilisation of field variability by intercrops

Atrial Fibrillation Ablation: Guidance by Newer Imaging Techniques

Ventricular tachycardia (VT) occurs in the diseased heart as well as in the normal heart but it is not always easy to distinguish. Ventricular tachycardias in the morphologically normal ventricle include idiopahic (fascicular) left ventricular tachycardia and out-flow-tract tachycardia from the right ventricular outflow tract (RVOT) or left ventricular outflow tract (LVOT), whereas VT in diseased heart comprises stable and unstable VT in post-infarction ventricle, VT in dilated cardiomyopathy, VT in arrhythmogenic right ventricular cardiomyopathy, and bundle branch re-entry

Cell mediated immune response dominates in experimental mammary gland Candida krusei infection in immunocompetent and immuno - compromised (nu/nu) mice

Experimental local mammary gland Candida krusei infection in immuno-competent and in congenic athymie nude BALB/c mice over a period of 21 days demonstrated that the immunocompetent mice readily cleared the infection whereas the infection persisted in the athymic mice. The fungal burden, however, was similar in the nude mice and in the immuno-compctcnt mice until day 18 after infection. The ratio Ofinterferony/interleukin-4 (1FN-y/IL-4) concentrations in supernatants from (ZonA stimulated splenocytcs of the infected mice indicated a predominant Th1 response to the C. krusei infection. Stimulated splenocytes of the infected immuno-competent mice synthesised significantly higher concentrations of the two eytokines than did the  splenocytes from the infected nude mice. The present study indicates that local C. krusei infection is associated with a predominant IFN-y-Th1 response although a gradual activation of the Th2 -arm (IL-4) of the immune system may beindicated late in the course of infection

Tissue doppler imaging predicts improved systolic performance and reversed left ventricular remodeling during long-term cardiac resynchronization therapy

AbstractObjectivesWe sought to evaluate the long-term impact of cardiac resynchronization therapy (CRT) on left ventricular (LV) performance and remodeling using three-dimensional echocardiography and tissue Doppler imaging (TDI).BackgroundThree-dimensional echocardiography and TDI allow rapid and accurate evaluation of LV volumes and performance.MethodsTwenty-five consecutive patients with severe heart failure and bundle branch block who underwent biventricular pacemaker implantation were included. Before and after implantation of the pacemaker, three-dimensional echocardiography and TDI were performed. These examinations were repeated at outpatient visits every six months.ResultsFive patients (20%) died during one-year follow-up. In the remaining 20 patients, significant reductions in LV end-diastolic volume and LV end-systolic volume of 9.6 ± 14% and 16.5 ± 15%, respectively (p < 0.01), could be demonstrated during long-term follow-up. Accordingly, LV ejection fraction increased by 21.7 ± 18% (p < 0.01). According to a newly developed TDI technique—tissue tracking—all regional myocardial segments improved their longitudinal systolic shortening (p < 0.01). The extent of the LV base displaying delayed longitudinal contraction, as detected by TDI before pacemaker implantation, predicted long-term efficacy of CRT. The QRS duration failed to predict resynchronization efficacy.ConclusionsCardiac resynchronization significantly improved LV function and reversed LV remodeling during long-term follow-up. Patients likely to benefit from CRT can be identified by TDI before implantation of a biventricular pacemaker

Probability Models for Degree Distributions of Protein Interaction Networks

The degree distribution of many biological and technological networks has been described as a power-law distribution. While the degree distribution does not capture all aspects of a network, it has often been suggested that its functional form contains important clues as to underlying evolutionary processes that have shaped the network. Generally, the functional form for the degree distribution has been determined in an ad-hoc fashion, with clear power-law like behaviour often only extending over a limited range of connectivities. Here we apply formal model selection techniques to decide which probability distribution best describes the degree distributions of protein interaction networks. Contrary to previous studies this well defined approach suggests that the degree distribution of many molecular networks is often better described by distributions other than the popular power-law distribution. This, in turn, suggests that simple, if elegant, models may not necessarily help in the quantitative understanding of complex biological processes.