210 research outputs found

    Two-Dimensional Vortex Lattice Melting

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    We report on a Monte-Carlo study of two-dimensional Ginzburg-Landau superconductors in a magnetic field which finds clear evidence for a first-order phase transition characterized by broken translational symmetry of the superfluid density. A key aspect of our study is the introduction of a quantity proportional to the Fourier transform of the superfluid density which can be sampled efficiently in Landau gauge Monte-Carlo simulations and which satisfies a useful sum rule. We estimate the latent heat per vortex of the melting transition to be 0.38kBTM\sim 0.38 k_B T_M where TMT_M is the melting temperature.Comment: 10 pages (4 figures available on request), RevTex 3.0, IUCM93-00

    Existence of the Abrikosov vortex state in two-dimensional type-II superconductors without pinning

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    Theory alternative to the vortex lattice melting theories is advertised. The vortex lattice melting theories are science fiction cond-mat/9811051 because the Abrikosov state is not the vortex lattice with crystalline long-range order. Since the fluctuation correction to the Abrikosov solution is infinite in the thermodynamic limit (K.Maki and H.Takayama, 1972) any fluctuation theory of the mixed state should consider a superconductor with finite sizes. Such nonperturbative theory for the easiest case of two-dimensional superconductor in the lowest Landau level approximation is presented in this work. The thermodynamic averages of the spatial average order parameter and of the Abrikosov parameter βa\beta_{a} are calculated. It is shown that the position H_{c4} of the transition into the Abrikosov state (i.e. in the mixed state with long-range phase coherence) depends strongly on sizes of two-dimensional superconductor. Fluctuations eliminate the Abrikosov vortex state in a wide region of the mixed state of thin films with real sizes and without pinning disorders, i.e. H_{c4} << H_{c2}. The latter has experimental corroboration in Phys.Rev.Lett. 75, 2586 (1995).Comment: 4 pages, 0 figure

    Early exercise in blunt chest wall trauma: protocol for a mixed-methods, multicentre, parallel randomised controlled trial (ELECT2 trial)

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    Introduction: Chronic pain and disability are now well-recognised long-term complications of blunt chest wall trauma. Limited research exists regarding therapeutic interventions that can be used to address these complications. A recent feasibility study was completed testing the methods of a definitive trial. This protocol describes the proposed definitive trial, the aim of which is to investigate the impact of an early exercise programme on chronic pain and disability in patients with blunt chest wall trauma. Methods/analysis: This mixed-methods, multicentre, parallel randomised controlled trial will run in four hospitals in Wales and one in England over 12-month recruitment period. Patients will be randomised to either the control group (routine physiotherapy input) or the intervention group (routine physiotherapy input plus a simple exercise programme completed individually by the patient). Baseline measurements including completion of two surveys (Brief Pain Inventory and EuroQol 5-dimensions, 5-Levels) will be obtained on initial assessment. These measures and a client services receipt inventory will be repeated at 3-month postinjury. Analysis of outcomes will focus on rate and severity of chronic pain and disability, cost-effectiveness and acceptability of the programme by patients and clinicians. Qualitative feedback regarding acceptability will be obtained through patient and clinician focus groups. Ethics/dissemination: London Riverside Research Ethics Committee (Reference number: 21/LO/0782) and the Health Research Authority granted approval for the trial in December 2021. Patient recruitment will commence in February 2022. Planned dissemination is through publication in a peer-reviewed Emergency Medicine Journal, presentation at appropriate conferences and to stakeholders at professional meetings. Trial registration number: ISRCTN65829737; Pre-results

    Forum on Scenarios for Climate and Societal Futures: Meeting Report

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    The second Scenarios Forum took place in June 2022 in Laxenburg, Austria. The goal of the second Scenarios Forum was to bring together the diverse set of communities using or developing scenarios in climate change and sustainability analysis to exchange experiences, ideas, and lessons learned; identify opportunities for synergies and collaboration between communities; reflect on the use of scenarios; and identify knowledge gaps for future research. The Scenarios Forum 2022 brought together over 500 researchers onsite and online to share experiences to date on progress toward this goal. The Forum confirmed that the SSP-RCP framework is being widely and increasingly used across a variety of research communities and assessment processes in the climate and biodiversity communities. Key discussions on future needs during the Scenarios Forum included the need for expansion of the solution space to facilitate a wider diversity of response strategies, broadening the labeling of scenarios to facilitate connection to other communities, initiating a discussion on high-end community scenarios and the tension in the scenarios framework between providing building-blocks for scientists and identifying key community-level scenarios

    Core-collapse supernova subtypes in luminous infrared galaxies

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    The fraction of core-collapse supernovae (CCSNe) occurring in the central regions of galaxies is not well constrained at present. This is partly because large-scale transient surveys operate at optical wavelengths, making it challenging to detect transient sources that occur in regions susceptible to high extinction factors. Here we present the discovery and follow-up observations of two CCSNe that occurred in the luminous infrared galaxy (LIRG) NGC 3256. The first, SN 2018ec, was discovered using the ESO HAWK-I/GRAAL adaptive optics seeing enhancer, and was classified as a Type Ic with a host galaxy extinction of AV = 2.1−0.1+0.3 mag. The second, AT 2018cux, was discovered during the course of follow-up observations of SN 2018ec, and is consistent with a subluminous Type IIP classification with an AV = 2.1 ± 0.4 mag of host extinction. A third CCSN, PSN J10275082−4354034 in NGC 3256, was previously reported in 2014, and we recovered the source in late-time archival Hubble Space Telescope imaging. Based on template light curve fitting, we favour a Type IIn classification for it with modest host galaxy extinction of AV = 0.3−0.3+0.4 mag. We also extend our study with follow-up data of the recent Type IIb SN 2019lqo and Type Ib SN 2020fkb that occurred in the LIRG system Arp 299 with host extinctions of AV = 2.1−0.3+0.1 and AV = 0.4−0.2+0.1 mag, respectively. Motivated by the above, we inspected, for the first time, a sample of 29 CCSNe located within a projected distance of 2.5 kpc from the host galaxy nuclei in a sample of 16 LIRGs. We find, if star formation within these galaxies is modelled assuming a global starburst episode and normal IMF, that there is evidence of a correlation between the starburst age and the CCSN subtype. We infer that the two subgroups of 14 H-poor (Type IIb/Ib/Ic/Ibn) and 15 H-rich (Type II/IIn) CCSNe have different underlying progenitor age distributions, with the H-poor progenitors being younger at 3σ significance. However, we note that the currently available sample sizes of CCSNe and host LIRGs are small, and the statistical comparisons between subgroups do not take into account possible systematic or model errors related to the estimated starburst ages.</p

    Age at first birth in women is genetically associated with increased risk of schizophrenia

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    Prof. Paunio on PGC:n jäsenPrevious studies have shown an increased risk for mental health problems in children born to both younger and older parents compared to children of average-aged parents. We previously used a novel design to reveal a latent mechanism of genetic association between schizophrenia and age at first birth in women (AFB). Here, we use independent data from the UK Biobank (N = 38,892) to replicate the finding of an association between predicted genetic risk of schizophrenia and AFB in women, and to estimate the genetic correlation between schizophrenia and AFB in women stratified into younger and older groups. We find evidence for an association between predicted genetic risk of schizophrenia and AFB in women (P-value = 1.12E-05), and we show genetic heterogeneity between younger and older AFB groups (P-value = 3.45E-03). The genetic correlation between schizophrenia and AFB in the younger AFB group is -0.16 (SE = 0.04) while that between schizophrenia and AFB in the older AFB group is 0.14 (SE = 0.08). Our results suggest that early, and perhaps also late, age at first birth in women is associated with increased genetic risk for schizophrenia in the UK Biobank sample. These findings contribute new insights into factors contributing to the complex bio-social risk architecture underpinning the association between parental age and offspring mental health.Peer reviewe
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