Entanglement of indistinguishable particles in condensed matter physics

The concept of entanglement in systems where the particles are indistinguishable has been the subject of much recent interest and controversy. In this paper we study the notion of entanglement of particles introduced by Wiseman and Vaccaro [Phys. Rev. Lett. 91, 097902 (2003)] in several specific physical systems, including some that occur in condensed matter physics. The entanglement of particles is relevant when the identical particles are itinerant and so not distinguished by their position as in spin models. We show that entanglement of particles can behave differently to other approaches that have been used previously, such as entanglement of modes (occupation-number entanglement) and the entanglement in the two-spin reduced density matrix. We argue that the entanglement of particles is what could actually be measured in most experimental scenarios and thus its physical significance is clear. This suggests entanglement of particles may be useful in connecting theoretical and experimental studies of entanglement in condensed matter systems.Comment: 13 pages, 6 figures, comments welcome, published version (minor changes, added references

On Approximation of the Eigenvalues of Perturbed Periodic Schrodinger Operators

This paper addresses the problem of computing the eigenvalues lying in the gaps of the essential spectrum of a periodic Schrodinger operator perturbed by a fast decreasing potential. We use a recently developed technique, the so called quadratic projection method, in order to achieve convergence free from spectral pollution. We describe the theoretical foundations of the method in detail, and illustrate its effectiveness by several examples.Comment: 17 pages, 2 tables and 2 figure

Bilateral Comparison of Elbow Ulnar Collateral Ligament Thickness in Division I Baseball Athletes

It has been established the mechanics of throwing a baseball contributes to ulnar collateral ligament (UCL) injury because of the repetitive valgus stress on the anterior band of the UCL, as it is the primary stabilizer of valgus stress in the elbow. This repetitive stress has been shown to cause adaptations in tensile properties leading to damage or failure of the UCL. Previous research has shown that ultrasound imaging may have the ability to detect changes in the UCL before the onset of symptoms in pitchers. PURPOSE: This study was performed to compare bilateral UCL thickness in Division I baseball players. METHODS: 22 Division I baseball players from the same university participated in this study. The players were separated into two groups based on position: pitchers (n=11; 190.9 ± 7.8 cm; 92.3 ± 11.2 kg) and position players (n=11; 184.6 ± 7.0 cm; 85.9 ± 10.8 kg). Ultrasound imaging was captured bilaterally on the players’ elbows using B-mode ultrasonography (LOGIQ, GE Healthcare). Players were tested seated in a reclined position with the arm resting on a plinth, shoulder abducted 90o, elbow extended 150o, and with forearm in a supinated position. The midpoint thickness of the UCL was measured in millimeters using ImageJ (National Institute of Health). The difference between throwing arm and non-throwing arm UCL thickness was calculated as ‘UCL Dif’. A two-way mixed factor ANOVA (position [pitcher vs position player] x arm [throwing arm and non-throwing arm]) was used to analyse UCL thickness. RESULTS:[BD1] There was no position x arm interaction (p=0.735); however, there were significant main effects for position (p = 0.003) and arm (p ≤ 0.001). When collapsed by position, UCL thickness was significantly greater in the throwing arm compared to the non-throwing arm (0.621 ± 0.008 mm vs. 0.581 ± 0.008 mm). When collapsed across arms, pitchers had significantly greater throwing arm UCL thickness compared to position players (0.618 ± 0.008 vs. 0.518 ± 0.008). CONCLUSION: The UCL thickness in pitchers’ throwing elbow was greater compared to position players. The greater UCL thickness in the throwing arm appears to be an adaptive change to the repetitive stress during a pitch. We believe the known relationships between UCL thickness, player position, and arm dominance can be best explained by positional demands and throwing style

497. Safety and tolerability of 2000mg intravenous sotrovimab dose in immunocompromised participants uninfected with SARS-CoV-2 in the PROTECT-V trial

Background: There remains a need for pre-exposure prophylaxis against SARS-CoV-2 infection in vulnerable patients in whom response to vaccination is often sub-optimal. The PROTECT-V platform trial is testing pre-exposure prophylactic interventions for COVID-19 in vulnerable patient populations: transplant recipients, individuals with oncological/haematological diagnoses, immune deficiency, autoimmune diseases requiring immunosuppression, and individuals receiving dialysis. Methods: Sotrovimab is a dual-action monoclonal antibody and the second agent to be added to the PROTECT-V platform (Clinicaltrials.gov: NCT04870333; EudraCT: 2020-004144-28). Although a single sotrovimab 500mg intravenous (IV) dose has been widely used for early treatment, data on a 2000mg IV dose are limited. Tolerability data in the first 143 participants randomized to this arm of the trial are presently available. Patients are randomized 1:1 sotrovimab to placebo. Data remain blinded. Results: Median age was 66 years (range 21 – 86) and 82 (57%) patients were female. 132 (96%) had received ≥3 doses of SARS-CoV-2 vaccine. Patient populations were: 82 (57%) autoimmune disease; 26 (18%) haematological/oncological diseases; 21 (15%) transplant recipients; 12 (8%) immunodeficiency; 2 (1%) on dialysis. Two (1%) participants experienced a mild infusion related reaction (IRR). The infusion was briefly interrupted, but completed. Thirty (21%) participants experienced at least one symptom in the 24 hours post-infusion, but none were severe or required hospital admission. The most common symptoms were dizziness (7 [5%]), headache (7 [5%]), rigors (5 [4%]) and fever (4 [3%]). No severe adverse events were reported within 72 hours of IMP infusion at the time of writing. The first 55 patients underwent routine hematological and biochemical blood test evaluation 72 hours post-infusion. Ten events from 9 participants exhibited worsening of laboratory parameters, meeting at least grade two DAIDS criteria or worse. None of these were clinically significant. Conclusion: A 2000mg IV dose of sotrovimab was tolerated well in this blinded analysis of immunocompromised participants, with no severe IRRs or significant change in haematological or biochemical markers up to 72 hours post infusion. Disclosures: Davinder Dosanjh, n/a, Astrazeneca: Honoraria|Astrazeneca: Employee|Boehringer Ingelheim: Advisor/Consultant|Boehringer Ingelheim: Honoraria|Gilead: Advisor/Consultant|GSK: Grant/Research Support|Synairgen: Advisor/Consultant Louise Crowley, n/a, GSK: Grant/Research Support Michael Chen-Xu, n/a, GSK: Grant/Research Support Rona M. Smith, MD MRCP, GSK: Grant/Research Support|Union Therapeutics: Grant/Research Suppor

Psychological barriers in oil futures markets

WTI and Brent futures are tested for the presence of psychological barriers around $10 price levels, applying a multiple hypothesis testing approach for statistical robustness. Psychological barriers are found to be present in Brent prices but not in WTI prices, which is argued to be due to the more prominent role that Brent plays as a global benchmark and, based on recent behavioural finance research, the greater complexity inherent in Brent fundamental value determination. Brent particularly displays evidence that when breaching a$10 barrier level from below with rising prices, the trend is for prices to fall on average subsequently. Similar behavioural-based patterns are evidenced at the $1 barrier level for the WTI-Brent spread. We show that psychological barriers only appear to influence prices in the pre-credit crisis period of 1990-2006, with such effects dissipating during the crisis and as markets reverted back to wider economy focused fundamentals. A range of reaction windows are applied with the main finding being that the trading potential around such psychological barrier levels is primarily in the immediate 1-5 days following a breach. The research contributes to the scant existing research on psychological influences on energy market traders, and suggests strong potential for further application of behavioural finance theories to improving understanding of energy markets price dynamics

Modelling the behaviour of the bonding of fibre reinforced concrete at the plate end

Comunicação apresentada em International Symposium Polymers in Concrete (ISPIC 2006), Guimarães, 2006In this paper, the finite element method is used to analyse the behaviour of concrete externally strengthened by fibre reinforced polymers (FRP). This model aims to analyse the stress distribution in the FRP-concrete interface at the plate end of a bending beam. The behaviour of the concrete-poxy-FRP arrangement is modelled with interface elements with initial zero thickness, using a discrete crack approach. A localized damage model is adopted for the interface and a parametric study is performed to approximate the material parameters adopted. The importance of each parameter is assessed. This model is subsequently verified using experimental data collected from the literature. Finally, a proposal is made concerning the adoption of a relation GF II/GF for the interface behaviour. Mention is also made to some of the main mathematical models found in the literature, which are compared to the present approach