Resistance of superconducting nanowires connected to normal metal leads

We study experimentally the low temperature resistance of superconducting nanowires connected to normal metal reservoirs. We find that a substantial fraction of the nanowires is resistive, down to the lowest temperature measured, indicative of an intrinsic boundary resistance due to the Andreev-conversion of normal current to supercurrent. The results are successfully analyzed in terms of the kinetic equations for diffusive superconductors

Erosive and non-erosive hand osteoarthritis. Use and limitations of two scoring systems

SummaryObjective:To assess the evolution and progression of osteoarthritis (OA) in the finger joints using anatomical changes on standard radiographs.Methods:Data obtained from 85 patients enrolled in a prospective study were used to evaluate systems to score the morbidity and the progression of the disease over 3 years. Posteroanterior (PA) radiographs of the metacarpophalangeal (MCP) and interphalangeal (IP) joints were obtained at entry and after 3 years. Assessment of the progression of OA over time is based on: (1) the increase in incidence of OA in previously normal joints during the study period, (2) the changes in the OA-associated features (osteophyte growth, loss of joint space, subchondral cysts or sclerosis) in the pathological finger joints (anatomical lesion progression score system), and (3) the recognition of consecutive anatomical phases in the course of ‘erosive’ OA (anatomical phase progression score system).Results:Almost 80% of the distal IP and 50% of the proximal IP were affected at study entry. In approximately 40% of the patients, the classical picture of OA of the IP joints was complicated by manifest erosive changes, which were followed by a repair phenomenon in the 'eroded' finger joints. MCP were less affected and showed the non-erosive picture of OA. Numbers of affected DIP, PIP and MCP joints per patient at entry did not differ from those after 3 years of follow-up. Two systems to score the progression of OA (anatomical lesion and anatomical phase progression score system) showed definite progression within 3 years of follow-up, especially in the IP joints. Since changes in both non-erosive and erosive joints were recorded by the anatomical lesion progression system, it was found much more sensitive to change than the anatomical phase progression system which principally recorded the progression through the destructive phases of erosive OA. The results of both progression score systems correlated well.Conclusion:Conventional radiographs can be used to assess the morbidity and progression of hand OA. The existence of non-erosive and erosive forms of OA of the finger joints necessitates the use of two scoring systems: the anatomical lesion progression score system and the anatomical phase progression score system

Optimized alkylated cyclodextrin polysulphates with reduced risks on thromboembolic accidents improve osteoarthritic chondrocyte metabolism

Objectives. To compare the ability of different cyclodextrin polysulphate (CDPS) derivatives to affect human articular cartilage cell metabolism in vitro

Cross-cultural adaptation of the Dutch version of the Functional Index for Hand Osteoarthritis (FIHOA) and a study on its construct validity

SummaryObjectiveTo validate a cross-culturally translated and adapted Dutch version of the Functional Index for Hand Osteoarthritis (FIHOA) in patients with osteoarthritis (OA) of the hands and to evaluate its construct validity by comparing with the Australian/Canadian Osteoarthritis Hand Index (AUSCAN).MethodsThe FIHOA was translated into Dutch and cross-culturally adapted. The questionnaire was administered to 72 patients with hand OA (female/male ratio: 64/8, handedness: right: 62/left: 7/both: 3). A visual analogue scale (VAS) pain scale (100mm) and the AUSCAN questionnaire were also recorded. An item–item analysis was performed. Test–retest reliability (time interval: 5 days) was assessed in 21 patients with intraclass correlation coefficient (ICC) and Bland and Altman graphical method. Construct validity was assessed by Spearman rank correlation coefficient between the FIHOA and AUSCAN.ResultsInternal consistency was high (Cronbach's alpha=0.89). All items, except for one (‘Are you able to clench the fist?’), and the mean total FIHOA scores were statistically different between the subgroups based on the VAS (mean total score=7.46 and 14.19, in a-/mild symptomatic and symptomatic group, respectively (P<0.001)).The Spearman's correlation between all subscales of the AUSCAN (pain, stiffness, functionality) and the FIHOA was good, especially with the subscale functionality (r=0.81, P<0.01). Test–retest reliability was excellent with an ICC of 0.96 for the total score and the Bland and Altman plot showing a homogeneous distribution of the differences.ConclusionThe psychometric properties of the Dutch version of the FIHOA are excellent. There is a good correlation between the FIHOA and all subscales of the AUSCAN, especially the subscale functionality

Improving transferability of introduced species' distribution models: new tools to forecast the spread of a highly invasive seaweed

Extent: 13 p.The utility of species distribution models for applications in invasion and global change biology is critically dependent on their transferability between regions or points in time, respectively. We introduce two methods that aim to improve the transferability of presence-only models: density-based occurrence thinning and performance-based predictor selection. We evaluate the effect of these methods along with the impact of the choice of model complexity and geographic background on the transferability of a species distribution model between geographic regions. Our multifactorial experiment focuses on the notorious invasive seaweed Caulerpa cylindracea (previously Caulerpa racemosa var. cylindracea) and uses Maxent, a commonly used presence-only modeling technique. We show that model transferability is markedly improved by appropriate predictor selection, with occurrence thinning, model complexity and background choice having relatively minor effects. The data shows that, if available, occurrence records from the native and invaded regions should be combined as this leads to models with high predictive power while reducing the sensitivity to choices made in the modeling process. The inferred distribution model of Caulerpa cylindracea shows the potential for this species to further spread along the coasts of Western Europe, western Africa and the south coast of Australia.Heroen Verbruggen, Lennert Tyberghein, Gareth S. Belton, Frederic Mineur, Alexander Jueterbock, Galice Hoarau, C. Frederico D. Gurgel, Olivier De Clerc

Superconductor-insulator transition in nanowires and nanowire arrays

Superconducting nanowires are the dual elements to Josephson junctions, with quantum phase-slip processes replacing the tunneling of Cooper pairs. When the quantum phase-slip amplitude ES is much smaller than the inductive energy EL, the nanowire responds as a superconducting inductor. When the inductive energy is small, the response is capacitive. The crossover at low temperatures as a function of ES/EL is discussed and compared with earlier experimental results. For one-dimensional and two-dimensional arrays of nanowires quantum phase transitions are expected as a function of ES/EL. They can be tuned by a homogeneous magnetic frustration.Comment: 15 pages, 10 figure