Energy Flow in the Hadronic Final State of Diffractive and Non-Diffractive Deep-Inelastic Scattering at HERA

An investigation of the hadronic final state in diffractive and non--diffractive deep--inelastic electron--proton scattering at HERA is presented, where diffractive data are selected experimentally by demanding a large gap in pseudo --rapidity around the proton remnant direction. The transverse energy flow in the hadronic final state is evaluated using a set of estimators which quantify topological properties. Using available Monte Carlo QCD calculations, it is demonstrated that the final state in diffractive DIS exhibits the features expected if the interaction is interpreted as the scattering of an electron off a current quark with associated effects of perturbative QCD. A model in which deep--inelastic diffraction is taken to be the exchange of a pomeron with partonic structure is found to reproduce the measurements well. Models for deep--inelastic $ep$ scattering, in which a sizeable diffractive contribution is present because of non--perturbative effects in the production of the hadronic final state, reproduce the general tendencies of the data but in all give a worse description.Comment: 22 pages, latex, 6 Figures appended as uuencoded fil

A Search for Selectrons and Squarks at HERA

Data from electron-proton collisions at a center-of-mass energy of 300 GeV are used for a search for selectrons and squarks within the framework of the minimal supersymmetric model. The decays of selectrons and squarks into the lightest supersymmetric particle lead to final states with an electron and hadrons accompanied by large missing energy and transverse momentum. No signal is found and new bounds on the existence of these particles are derived. At 95% confidence level the excluded region extends to 65 GeV for selectron and squark masses, and to 40 GeV for the mass of the lightest supersymmetric particle.Comment: 13 pages, latex, 6 Figure

Psycho-social factors associated with mental resilience in the Corona lockdown

The SARS-CoV-2 pandemic is not only a threat to physical health but is also having severe impacts on mental health. Although increases in stress-related symptomatology and other adverse psycho-social outcomes, as well as their most important risk factors have been described, hardly anything is known about potential protective factors. Resilience refers to the maintenance of mental health despite adversity. To gain mechanistic insights about the relationship between described psycho-social resilience factors and resilience specifically in the current crisis, we assessed resilience factors, exposure to Corona crisis-specific and general stressors, as well as internalizing symptoms in a cross-sectional online survey conducted in 24 languages during the most intense phase of the lockdown in Europe (22 March to 19 April) in a convenience sample of N = 15,970 adults. Resilience, as an outcome, was conceptualized as good mental health despite stressor exposure and measured as the inverse residual between actual and predicted symptom total score. Preregistered hypotheses (osf.io/r6btn) were tested with multiple regression models and mediation analyses. Results confirmed our primary hypothesis that positive appraisal style (PAS) is positively associated with resilience (p < 0.0001). The resilience factor PAS also partly mediated the positive association between perceived social support and resilience, and its association with resilience was in turn partly mediated by the ability to easily recover from stress (both p < 0.0001). In comparison with other resilience factors, good stress response recovery and positive appraisal specifically of the consequences of the Corona crisis were the strongest factors. Preregistered exploratory subgroup analyses (osf.io/thka9) showed that all tested resilience factors generalize across major socio-demographic categories. This research identifies modifiable protective factors that can be targeted by public mental health efforts in this and in future pandemics

Salvage therapy of progressive and recurrent Hodgkin's disease: results from a multicenter study of the pediatric DAL/GPOH-HD study group.

Contains fulltext : 48383.pdf (publisher's version ) (Closed access)PURPOSE: To evaluate a salvage therapy (ST-HD-86) for patients with progressive and relapsed Hodgkin's disease after primary treatment in the pediatric DAL/GPOH studies. The essential chemotherapeutic regimens were ifosfamide, etoposide, and prednisone (IEP) and doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD). METHODS: One hundred seventy-six patients with progression (n = 51) or first relapse (n = 125) were enrolled by 67 centers. The median time from initial diagnosis to progression/relapse was 1.1 year (range, 0.1 to 15.3 years), and the patients' median age was 14.7 years (range, 4.3 to 24.5 years). Salvage chemotherapy consisted of two to three cycles of IEP alternating with one to two cycles of ABVD supplemented in part by one to two cycles of cyclophosphamide, vincristine, procarbazine, and prednisone or lomustine (CCNU), etoposide, and prednimustine. Radiotherapy was given to involved areas using individualized doses. In the 1990s, additional high-dose chemotherapy with autologous stem-cell transplantation (SCT) was introduced for patients with unfavorable prognosis. RESULTS: Disease-free survival (DFS) and overall survival (OS) after 10 years are 62% and 75%, respectively (SE, 4% each). Of 176 patients, 73 suffered second events. The risk-factor analysis revealed the time to progression/relapse as the strongest prognostic factor (P = .0001). Patients with progression have an inferior outcome (DFS, 41%; OS, 51%), whereas patients with late relapse (> 12 months after end of therapy) do well (DFS, 86%; OS, 90%), although none of them received SCT in second remission. CONCLUSION: The result can be considered favorable. Whereas the salvage strategy for progressive disease has to be optimized further, it is possible to reduce intensity and avoid SCT in late relapses after Hodgkin's disease in childhood/adolescence