Reduced leakage current in Josephson tunnel junctions with codeposited barriers

Josephson junctions were fabricated using two different methods of barrier formation. The trilayers employed were Nb/Al-AlOx/Nb on sapphire, where the first two layers were epitaxial. The oxide barrier was formed either by exposing the Al surface to O2 or by codepositing Al in an O2 background. The codeposition process yielded junctions that showed the theoretically predicted subgap current and no measurable shunt conductance. In contrast, devices with barriers formed by thermal oxidation showed a small shunt conductance in addition to the predicted subgap current.Comment: 3 pages, 4 figure

Is loss in femorotibial cartilage thickness related to severity of contra-lateral radiographic knee osteoarthritis? – Longitudinal data from the Osteoarthritis Initiative

SummaryObjectiveAnti-catabolic disease modifying drugs (DMOADs) aim to reduce cartilage loss in knee osteoarthritis (KOA). Testing such drugs in clinical trials requires sufficient rates of loss in the study participants to occur, preferably at a mild disease stage where cartilage can be preserved. Here we analyze a “progression” model in mild radiographic KOA (RKOA), based on contra-lateral radiographic status.MethodsWe studied 837 participants (62.4 ± 9 yrs; 30 ± 4.9 kg/m²; 61.8% women) from the Osteoarthritis Initiative (OAI) with mild to moderate RKOA (Kellgren Lawrence grade [KLG] 2–3) and with/without Osteoarthritis Research Society International (OARSI) atlas radiographic joint space narrowing (JSN). These had quantitative measurements of subregional femorotibial cartilage thickness from magnetic resonance imaging (MRI) at baseline and 1-year follow-up. They were stratified by contra-lateral knee status: no (KLG 0/1), definite (KLG2) and moderate RKOA (KLG 3/4).ResultsKLG2 knees with JSN and moderate contra-lateral RKOA had (P = 0.008) greater maximum subregional cartilage loss −220 μm [95% confidence interval (CI) −255, −184 μm] than those without contra-lateral RKOA −164 μm [−187, −140 μm]. Their rate of subregional cartilage loss was similar and not significantly different (P = 0.61) to that in KLG 3 knees without contra-lateral RKOA (−232 μm; [−266; −198 μm]). The effect of contra-lateral RKOA status was less in KLG2 knees without JSN, and in KLG3 knees.ConclusionKLG2 knees with JSN and moderate contra-lateral RKOA, display relatively high rates of subregional femorotibial cartilage loss, despite being at a relatively mild stage of RKOA. They may therefore provide a unique opportunity for recruitment in clinical trials that explore the efficacy of anti-catabolic DMOADs on structural progression

Phonon-pump XUV-photoemission-probe in graphene: evidence for non-adiabatic heating of Dirac carriers by lattice deformation

We modulate the atomic structure of bilayer graphene by driving its lattice at resonance with the in-plane E1u lattice vibration at 6.3um. Using time- and angle-resolved photoemission spectroscopy (tr-ARPES) with extreme ultra-violet (XUV) pulses, we measure the response of the Dirac electrons near the K-point. We observe that lattice modulation causes anomalous carrier dynamics, with the Dirac electrons reaching lower peak temperatures and relaxing at faster rate compared to when the excitation is applied away from the phonon resonance or in monolayer samples. Frozen phonon calculations predict dramatic band structure changes when the E1u vibration is driven, which we use to explain the anomalous dynamics observed in the experiment.Comment: 16 pages, 8 figure

Conferring legal personality on the world\u27s rivers: A brief intellectual assessment

The following compilation is substantially reproduced and adapted from a series of essays that appeared in the blog of the International Water Law Project (www.inter nationalwaterlaw.org). The series was solicited in response to the unique recent phenomenon in which a number of courts and legislatures around the world have conferred legal personality on particular rivers. What resulted is a fantastic, thoughtprovoking and timely compilation. In effect, various water bodies around the world have been accorded legal rights – some though legislative actions and others via judicial decisions – that in some jurisdictions, equate with those recognized in human beings. Although there may be interesting parallels in rights accorded to corporations, children and the intellectually challenged, the practical implications of these particular actions are still not well recognized or understood. Harkening back to Christopher Stone’s remarkable 1972 article ‘Should Trees Have Standing? Toward Legal Rights for Natural Objects’, the series pursued some of the most fascinating and perplexing issues surrounding legal personality in rivers. What actual rights might such legal personality provide? How does a river represent itself in court and before other societal institutions? If a river can suffer harm and sue alleged perpetrators of that harm, might it be subject to lawsuits for damages it might inflict as a result of flooding? What resources might a river have at its disposal to protect its rights? Does the recognition of such rights comport with the rights, interests and perspective of indigenous peoples? These are just some of the unique issues considered in these provocative essays. The legislative and judicial actions discussed in this series are a novel legal approach to the management of critical freshwater resources. These mechanisms, however, have yet to be fully evaluated, scrutinized and tested. The essays that follow constitute a thought-provoking effort to contribute to that assessment. Moreover, they were written with the sincere objective of ensuring the sustainability of unique freshwater resources around the world. The International Water Law Project is itself a unique institution. Existing solely on the Internet, the website is one of the premier resources and clearinghouses for information on international water law and policy. Its purpose is to educate and provide relevant resources to researchers and the public and to facilitate cooperation over the world’s freshwater resources

Sub-cycle multidimensional spectroscopy of strongly correlated materials

Strongly correlated solids are extremely complex and fascinating quantum systems, where new states continue to emerge, especially when interaction with light triggers interplay between them. In this interplay, sub-laser-cycle electron response is particularly attractive as a tool for ultrafast manipulation of matter at PHz scale. Here we introduce a new type of non-linear multidimensional spectroscopy, which allows us to unravel the sub-cycle dynamics of strongly correlated systems interacting with few-cycle infrared pulses and the complex interplay between different correlated states evolving on the sub-femtosecond time-scale. We demonstrate that single particle sub-cycle electronic response is extremely sensitive to correlated many-body dynamics and provides direct access to many body response functions. For the two-dimensional Hubbard model under the influence of ultra-short, intense electric field transients, we demonstrate that our approach can resolve pathways of charge and energy flow between localized and delocalized many-body states on the sub-cycle time scale and follow the creation of a highly correlated state surviving after the end of the laser pulse. Our findings open a way towards a regime of imaging and manipulating strongly correlated materials at optical rates, beyond the multi-cycle approach employed in Floquet engineering, with the sub-cycle response being a key tool for accessing many body phenomena.Comment: 10 pages, 4, figures, Methods (5 pages), Supplementary information (4 figures, 4 pages

Tibial coverage, meniscus position, size and damage in knees discordant for joint space narrowing - data from the Osteoarthritis Initiative.

INTRODUCTION: Meniscal extrusion is thought to be associated with less meniscus coverage of the tibial surface, but the association of radiographic disease stage with quantitative measures of tibial plateau coverage is unknown. We therefore compared quantitative and semi-quantitative measures of meniscus position and morphology in individuals with bilateral painful knees discordant on medial joint space narrowing (mJSN). METHODS: A sample of 60 participants from the first half (2,678 cases) of the Osteoarthritis Initiative cohort fulfilled the inclusion criteria: bilateral frequent pain, Osteoarthritis Research Society International (OARSI) mJSN grades 1-3 in one, no-JSN in the contra-lateral (CL), and no lateral JSN in either knee (43 unilateral mJSN1; 17 mJSN2/3; 22 men, 38 women, body mass index (BMI) 31.3 + 3.9 kg/m(2)). Segmentation and three-dimensional quantitative analysis of the tibial plateau and meniscus, and semi-quantitative evaluation of meniscus damage (magnetic resonance imaging (MRI) osteoarthritis knee score = MOAKS) was performed using coronal 3T MR images (MPR DESSwe and intermediate-weighted turbo spin echo (IW-TSE) images). CL knees were compared using paired t-tests (between-knee, within-person design). RESULTS: Medial tibial plateau coverage was 36 + 9% in mJSN1 vs 45 + 8% in CL no-JSN knees, and was 31 + 9% in mJSN2/3 vs 46 + 6% in no-JSN knees (both P < 0.001). mJSN knees showed greater meniscus extrusion and damage (MOAKS), but no significant difference in meniscus volume. No significant differences in lateral tibial coverage, lateral meniscus morphology or position were observed. CONCLUSIONS: Knees with medial JSN showed substantially less medial tibial plateau coverage by the meniscus. We suggest that the less meniscal coverage, i.e., less mechanical protection may be a reason for greater rates of cartilage loss observed in JSN knees. Copyright 2012 Osteoarthritis Research Society International. All rights reserved

Exchange Field Induced Magnetoresistance in Colossal Magnetoresistance Manganites

The effect of an exchange field on electrical transport in thin films of metallic ferromagnetic manganites has been investigated. The exchange field was induced both by direct exchange coupling in a ferromagnet/antiferromagnet multilayer and by indirect exchange interaction in a ferromagnet/paramagnet superlattice. The electrical resistance of the manganite layers was found to be determined by the absolute value of the vector sum of the effective exchange field and the external magnetic field.Comment: 5 pages, 4 figure

Internal Anisotropy of Collision Cascades

We investigate the internal anisotropy of collision cascades arising from the branching structure. We show that the global fractal dimension cannot give an adequate description of the geometrical structure of cascades because it is insensitive to the internal anisotropy. In order to give a more elaborate description we introduce an angular correlation function, which takes into account the direction of the local growth of the branches of the cascades. It is demonstrated that the angular correlation function gives a quantitative description of the directionality and the interrelation of branches. The power law decay of the angular correlation is evidenced and characterized by an exponent and an angular correlation length different from the radius of gyration. It is demonstrated that the overlapping of subcascades has a strong effect on the angular correlation.Comment: RevteX, 8 pages, 6 .eps figures include

Relationship between knee pain and the presence, location, size and phenotype of femorotibial denuded areas of subchondral bone as visualized by MRI

Objective: Conflicting associations between imaging biomarkers and pain in knee osteoarthritis (OA) have been reported. A relation between pain and denuded areas of subchondral bone (dABs) has been suggested and this study explores this relationship further by relating the presence, phenotype, location and size of dABs to different measures of knee pain. Methods: 633 right knees from the Osteoarthritis Initiative (OAI) (250 men, age 61.7 +/- 9.6 yrs, BMI 29.4 +/- 4.7 kg/m(2)) were included. Manual segmentation of the femorotibial cartilage plates was performed on 3 T coronal fast low angle shot with water excitation (FLASHwe) images. dABs were defined as areas where the subchondral bone was uncovered by cartilage. The following measures of pain were used: weightbearing-, non-weightbearing-, moderate-to-severe-, infrequent- and frequent knee pain. Results: Using pain measures from subjects without dABs as a reference, those with at least one dAB had a 1.64-fold higher prevalence ratio [PR, 95% confidence interval (CI) 1.24-2.18] to have frequent and 1.45-fold higher for moderate-to-severe knee pain (95% CI 1.13-1.85). Subjects with dABs in central subregions had a 1.53-fold increased prevalence of having weightbearing pain (95% Cl 1.20-1.97), especially when the central subregion was moderately (>10%) denuded (PR 1.81, 95% CI 135-2.42). Individuals with cartilage-loss-type dABs had a slightly higher prevalence (PR 1.13, 95% CI 1.00-1.27) of having frequent knee pain compared to individuals with intra-chondral-osteophyte-type dABs. Conclusion: This study supports a positive relation between femorotibial dABs and knee pain, especially when the dABs are located centrally (i.e., in weightbearing regions) or when the respective central subregion is moderately denuded. (C) 2013 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved