Scratching the surface:Footprint of a late Carboniferous ice sheet

International audienceField observations in conjunction with aerial images from an unmanned aerial vehicle were used to create the first map of a glacial unconformity underlying the late Carboniferous Dwyka Group of South Africa. Crosscutting relationships reveal that the glacial unconformity at Oorlogskloof, in which flutes, grooves, and striae were ploughed into unconsolidated sand, formed in a three-phased process charting a periodic shift in the locus of subglacial erosion. The unconformity formed by a periodically decoupled ice sheet in a probable tidewater setting. This model contrasts with earlier views that the structures simply record progressive ice-margin liftoff during transgression, and they provide unique insight into the complex temporal development of a 300 Ma subglacial environment

3D Model of a hand specimen of the Rasthof Formation bearing lonestones and granule clusters

As supplementary material, we present a 3 D model of a hand specimen of the Rasthof Formation in .fbx format. It can be viewed in the free Windows 3D Viewer app, and imported to various other software platforms e.g. Agisoft Metashape. The model was constructed from 119 photos taken by Christoph Kettler in May 2020. The photographs were aligned, a dense point cloud generated, textured, and a 3 D model created following the standard photogrammetry workflow in Agisoft Metashape. The model was then exported to .fbx format for viewing on multiple different platforms

Visible-to-telecom quantum frequency conversion of light from a single quantum emitter

Quantum frequency conversion (QFC), a nonlinear optical process in which the frequency of a quantum light field is altered while conserving its non-classical correlations, was first demonstrated 20 years ago. Meanwhile, it is considered an essential tool for the implementation of quantum repeaters since it allows for interfacing quantum memories with telecom-wavelength photons as quantum information carriers. Here we demonstrate efficient (>30%) QFC of visible single photons (711 nm) emitted by a quantum dot (QD) to a telecom wavelength (1,313 nm). Analysis of the first and second-order coherence before and after wavelength conversion clearly proves that important properties, such as the coherence time and photon antibunching, are fully conserved during the frequency translation process. Our findings underline the great potential of single photon sources on demand in combination with QFC as a promising technique for quantum repeater schemes.Comment: 11 pages, 4 figure

Bullying girls - Changes after brief strategic family therapy: A randomized, prospective, controlled trial with one-year follow-up

Background: Many girls bully others. They are conspicuous because of their risk-taking behavior, increased anger, problematic interpersonal relationships and poor quality of life. Our aim was to determine the efficacy of brief strategic family therapy (BSFT) for bullying-related behavior, anger reduction, improvement of interpersonal relationships, and improvement of health-related quality of life in girls who bully, and to find out whether their expressive aggression correlates with their distinctive psychological features. Methods: 40 bullying girls were recruited from the general population: 20 were randomly selected for 3 months of BSFT. Follow-up took place 12 months after the therapy had ended. The results of treatment were examined using the Adolescents' Risk-taking Behavior Scale (ARBS), the State-Trait Anger Expression Inventory (STAXI), the Inventory of Interpersonal Problems (IIP-D), and the SF-36 Health Survey (SF-36). Results: In comparison with the control group (CG) (according to the intent-to-treat principle), bullying behavior in the BSFT group was reduced (BSFT-G from n = 20 to n = 6; CG from n = 20 to n = 18, p = 0.05) and statistically significant changes in all risk-taking behaviors (ARBS), on most STAXI, IIP-D, and SF-36 scales were observed after BSFT. The reduction in expressive aggression (Anger-Out scale of the STAXI) correlated with the reduction on several scales of the ARBS, IIP-D, and SF-36. Follow-up a year later showed relatively stable events. Conclusions: Our findings suggest that bullying girls suffer from psychological and social problems which may be reduced by the use of BSFT. Expressive aggression in girls appears to correlate with several types of risk-taking behavior and interpersonal problems, as well as with health-related quality of life. Copyright (c) 2006 S. Karger AG, Basel

Outcome analysis following removal of locking plate fixation of the proximal humerus

<p>Abstract</p> <p>Background</p> <p>Concerning surgical management experience with locking plates for proximal humeral fractures has been described with promising results. Though, distinct hardware related complaints after fracture union are reported. Information concerning the outcome after removal of hardware from the proximal humerus is lacking and most studies on hardware removal are focused on the lower extremity. Therefore the aim of this study was to analyze the functional short-term outcome following removal of locking plate fixation of the proximal humerus.</p> <p>Methods</p> <p>Patients undergoing removal of a locking plate of the proximal humerus were prospectively followed. Patients were subdivided into the following groups: Group HI: symptoms of hardware related subacromial impingement, Group RD: persisting rotation deficit, Group RQ: patients with request for a hardware removal. The clinical (Constant-Murley score) and radiologic (AP and axial view) follow-up took place three and six months after the operation. To evaluate subjective results, the Medical Outcomes Study Short Form-36 (SF-36), was completed.</p> <p>Results</p> <p>59 patients were included. The mean length of time with the hardware in place was 15.2 ± 3.81 months. The mean of the adjusted overall Constant score before hardware removal was 66.2 ± 25.2% and increased significantly to 73.1 ± 22.5% after 3 months; and to 84.3 ± 20.6% after 6 months (p < 0.001). The mean of preoperative pain on the VAS-scale before hardware removal was 5.2 ± 2.9, after 6 months pain in all groups decreased significantly (p < 0.001). The SF-36 physical component score revealed a significant overall improvement in both genders (p < 0.001) at six months.</p> <p>Conclusion</p> <p>A significant improvement of clinical outcome following removal was found. However, a general recommendation for hardware removal is not justified, as the risk of an anew surgical and anesthetic procedure with all possible complications has to be carefully taken into account. However, for patients with distinct symptoms it might be justified.</p

Does fixed-angle plate osteosynthesis solve the problems of a fractured proximal humerus?: A prospective series of 87 patients

Background and purpose There is considerable controversy about the treatment of complex, displaced proximal humeral fractures. Various types of head-preserving osteosynthesis have been suggested. This prospective case series was designed to evaluate the perioperative and early postoperative complications associated with fixed-angle implants and to record outcome after bone healing

Practical examination of bystanders performing Basic Life Support in Germany: a prospective manikin study

<p>Abstract</p> <p>Background</p> <p>In an out-of-hospital emergency situation bystander intervention is essential for a sufficient functioning of the chain of rescue. The basic measures of cardiopulmonary resuscitation (Basic Life Support – BLS) by lay people are therefore definitely part of an effective emergency service of a patient needing resuscitation. Relevant knowledge is provided to the public by various course conceptions. The learning success concerning a one day first aid course ("LSM" course in Germany) has not been much investigated in the past. We investigated to what extent lay people could perform BLS correctly in a standardised manikin scenario. An aim of this study was to show how course repetitions affected success in performing BLS.</p> <p>Methods</p> <p>The "LSM course" was carried out in a standardised manner. We tested prospectively 100 participants in two groups (<b>Group 1: </b>Participants with previous attendance of a BLS course; <b>Group 2: </b>Participants with no previous attendance of a BLS course) in their practical abilities in BLS after the course. Success parameter was the correct performance of BLS in accordance with the current ERC guidelines.</p> <p>Results</p> <p>Twenty-two (22%) of the 100 investigated participants obtained satisfactory results in the practical performance of BLS. Participants with repeated participation in BLS obtained significantly better results (<b>Group 1: </b>32.7% vs. <b>Group 2: </b>10.4%; p < 0.01) than course participants with no relevant previous knowledge.</p> <p>Conclusion</p> <p>Only 22% of the investigated participants at the end of a "LSM course" were able to perform BLS satisfactorily according to the ERC guidelines. Participants who had previously attended comparable courses obtained significantly better results in the practical test. Through regular repetitions it seems to be possible to achieve, at least on the manikin, an improvement of the results in bystander resuscitation and, consequently, a better patient outcome. To validate this hypothesis further investigations are recommended by specialised societies.</p