48 research outputs found
Scaling properties of high p_T inclusive hadron production
We analyze the scaling properties of inclusive hadron production in
proton-proton and in heavy ion collisions from fixed target to collider
energies. At large transverse momentum p_T, the invariant cross section
exhibits a power-like behavior Ed^3\sigma/d^3p\propto p_T^{-n} at fixed
transverse x, x_T=2p_T/\sqrt{s}, and fixed center-of-mass scattering angle
\theta_{cm}. Knowledge of the exponent n allows one to draw conclusions about
the production mechanisms of hadrons, which are poorly known, even at high p_T.
We find that high-p_T hadrons are produced by different mechanisms at
fixed-target and collider energies. For pions, higher-twist subprocesses where
the pion is produced directly dominate at fixed target energy, while
leading-twist partonic scattering plus fragmentation is the most important
mechanism at collider energies. High-p_T baryons on the other hand appear to be
produced by higher-twist mechanisms at all available energies. The higher-twist
mechanism of direct proton production can be verified experimentally by testing
whether high p_T protons are produced as single hadrons without accompanying
secondaries. In addition, we find that medium-induced gluon radiation in heavy
ion collisions can violate scaling.Comment: 14 pages, 3 figure
Temporal Vagueness, Coordination and Communication
How is it that people manage to communicate even when they implicitly differ on the meaning of the terms they use? Take an innocent-sounding expression such as tomorrow morning. What counts as morning? There is a surprising amount of variation across different people.
Sustainability Science
Meeting fundamental human needs while preserving earth's life support systems will require an accelerated transition toward sustainability. A new field of sustainability science is emerging that seeks to understand the fundamental character of interactions between nature and society and to encourage the interactions along more sustainable trajectories. Such an integrated, place-based science will require new research strategies and institutional innovations to enable them especially in developing countries still separated by deepening divides from mainstream science. Sustainability science needs to be widely discussed in the scientific community, reconnected to the political agenda for sustainable development, and become a major focus for research
Auswirkungen anthropogener Klimaveränderungen auf die Ertragsleistung von Weizen in Europa: Ergebnisse des Europäischen Verbundprojektes ESPACE-Wheat
Simulation of particle suspensions at the Institute for Computational Physics
In this report we describe some of our projects related to the simulation of particle-laden flows. We give a short introduction to the topic and the methods used, namely the Stochastic Rotation Dynamics and the lattice Boltzmann method. Then, we show results from our work related to the behaviour of claylike colloids in shear flow as well as structuring effects of particles in the vicinity of rigid walls
Occurrence, risk factors and outcome of adenovirus infection in adult recipients of allogeneic hematopoietic stem cell transplantation.
BACKGROUND: Adenovirus (ADV) infections can have a high mortality in immunocompromised patients and are difficult to treat. OBJECTIVES AND STUDY DESIGN: We retrospectively analyzed occurrence and risk factors of ADV infection in 399 adults with hematological disorders undergoing hematopoietic stem cell transplantation (allo-HSCT), focusing on alternative donor transplantation (ADT) and disseminated disease. RESULTS: ADV infection occurred in 42 patients (10.5%). Disease was localized in 18 and disseminated in 6 patients. ADV infection was observed in 15% after ADT, performed in 29% of all recipients, and was less frequent (6%) in T-cell-replete (TCR) haploidentical transplantation using post-transplantation cyclophosphamide (PTCY) than in other ADT protocols. Lower age, the use of alternative donor grafts and acute graft-versus-host disease (GvHD)≥grade II were risk factors for ADV infection. After failure of standard antiviral treatment, three patients with disseminated ADV disease received one dose of ADV-specific T cells, resulting in virological response in 2/3 patients, clearance of ADV viremia in 2/2 patients, and survival of 1/3 patients; both patients with pneumonia died. CONCLUSIONS: ADV infection was of moderate occurrence in our adult recipients of allo-HSCT despite a high proportion of potential high-risk patients receiving ADT. TCR strategies using PTCY might limit ADV complications in haploidentical transplantation. Despite feasible adoptive therapy strategies, outcome of disseminated disease remains dismal
Comparative Investigations on the Nitrogen Metabolism of Two Agrostis tenuis Populations from a Metalliferous Waste1)1)Dedicated to Prof. Dr. L. Steubing on the occasion of her 60th birthday.
Virus infection in HLA-haploidentical hematopoietic stem cell transplantation: Incidence in the context of immune recovery in two different transplantation settings.
We retrospectively compared the incidence of virus infections and outcome in the context of immune reconstitution in two different HLA-haploidentical transplantation (haplo-HSCT) settings. The first was a combined T-cell-replete and T-cell-deplete approach using antithymocyte globulin (ATG) prior to transplantation in patients with hematological diseases (cTCR/TCD group, 28 patients; median age 31 years). The second was a T-cell-replete (TCR) approach using high-dose posttransplantation cyclophosphamide (TCR/PTCY group, 27 patients; median age 43 years). The incidence of herpesvirus infection was markedly lower in the TCR/PTCY (22 %) than in the cTCR/TCD group (93 %). Recovery of CD4+ T cells on day +100 was faster in the TCR/PTCY group. CMV reactivation was 30 % in the TCR/PTCY compared to 57 % in the cTCR/TCD group, and control with antiviral treatment was superior after TCR/PTCY transplantation (100 vs 50 % cTCR/TCD). Twenty-five percent of the patients in the cTCR/TCD group but no patient in the TCR/PTCY group developed PTLD. While 1-year OS was not different (TCR/PTCY 59 % vs cTCR/TCD 39 %; p = 0.28), virus infection-related mortality (VIRM) was significantly lower after TCR/PTCY transplantation (1-year VIRM, 0 % TCR/PTCY vs 29 % cTCR/TCD; p = 0.009). On day +100, predictors of better OS were lymphocytes >300/μl, CD3+ T cells >200/μl, and CD4+ T cells >150/μl, whereas the application of steroids >1 mg/kg was correlated with worse outcome. Our results suggest that by presumably preserving antiviral immunity and allowing fast immune recovery of CD4+ T cells, the TCR approach using posttransplantation cyclophosphamide is well suited to handle the important issue of herpesvirus infection after haplo-HSCT