525 research outputs found
Soft Gamma Rays from Heavy WIMPs
We propose an explanation of the galactic center gamma ray excess by
supersymmetric WIMPs as heavy as 500 GeV. The lightest neutralino annihilates
into vector-like leptons or quarks which cascade decay through intermediate
Higgs bosons. Due to the long decay chains, the gamma ray spectrum is much
softer than naively expected and peaks at GeV energies. The model predicts
correlated diboson and dijet signatures to be tested at the LHC.Comment: 8 pages, 8 figures; v2: focus on gamma ray excess, matches published
versio
Innovationen im Mobile Government – Eine Analyse von Dienstattraktivitäten und Motivationen von deutschen Kommunen
Städte und Gemeinden stehen unter einem immerwährenden Sparzwang. Gleichzeitig ergeben sich mit der wachsenden Beliebtheit des mobilen Internets innovative Anwendungsszenarien des Mobile Government. Diese Arbeit analysiert ein breites Spektrum an Mobile Government-Diensten aus der Sicht von kommunalen IT-Entscheidern und untersucht die organisationalen Faktoren, welche die wahrgenommene Attraktivität dieser Dienste beeinflussen. Hierzu wird auf Basis der Literatur sowie einer Serie von Interviews ein Modell bestehend aus drei Hauptdimensionen (Effizienzstreben, Innovationsstreben und IT-Erfahrenheit) abgeleitet. Wir testen das Modell empirisch mit Hilfe des Partial Least Square-Ansatzes in einer Erhebung mit 50 deutschen Städten und clustern die Fälle entsprechend der postulierten Dimensionen. Die Ergebnisse deuten darauf hin, dass sich die Motivationen in Städten mit hoher Ausprägung der wahrgenommenen Dienstattraktivität signifikant von denen mit geringer Ausprägung unterscheiden und dass die Innovatoren und IT-Erfahrenen unter den Städten in den nächsten drei Jahren deutlich stärker in mobile Dienste investieren werden als andere Kommunen
Phase 2 Study of Anti-Human Cytomegalovirus Monoclonal Antibodies for Prophylaxis in Hematopoietic Cell Transplantation.
Human cytomegalovirus (HCMV) can cause significant disease in immunocompromised patients, and treatment options are limited by toxicities. CSJ148 is a combination of two anti-HCMV human monoclonal antibodies (LJP538 and LJP539) that bind to and inhibit the functions of viral HCMV glycoprotein B (gB) and the pentameric complex, consisting of glycoproteins gH, gL, UL128, UL130, and UL131. In this phase 2, randomized, placebo-controlled trial, we evaluated the safety and efficacy of CSJ148 for prophylaxis of HCMV in patients undergoing allogeneic hematopoietic stem cell transplantation. As would be expected in the study population, all the patients (100%) reported at least one treatment-emergent adverse event. There were 22 deaths during this study, and over 80% of the patients receiving placebo or CSJ148 developed at least one adverse event of grade 3 or higher severity. No subject who received antibody developed a hypersensitivity- or infusion-related reaction. CSJ148-treated patients showed trends toward decreased viral load, shorter median duration of preemptive therapy, and fewer courses of preemptive therapy. However, the estimated probability that CSJ148 decreases the need for preemptive therapy compared to placebo was 69%, with a risk ratio of 0.89 and a 90% credible interval of 0.61 to 1.31. The primary efficacy endpoint was therefore not met, indicating that CSJ148 did not prevent clinically significant HCMV reactivation in recipients of allogeneic hematopoietic cell transplants. (This study has been registered at ClinicalTrials.gov under identifier NCT02268526 and at EudraCT under number 2017-002047-15.)
The Fungicide Chlorothalonil Is Nonlinearly Associated with Corticosterone Levels, Immunity, and Mortality in Amphibians
Background: Contaminants have been implicated in declines of amphibians, a taxon with vital systems similar to those of humans. However, many chemicals have not been thoroughly tested on amphibians or do not directly kill them
Edge magnetoplasmons in periodically modulated structures
We present a microscopic treatment of edge magnetoplasmons (EMP's) within the
random-phase approximation for strong magnetic fields, low temperatures, and
filling factor , when a weak short-period superlattice potential is
imposed along the Hall bar. The modulation potential modifies both the spatial
structure and the dispersion relation of the fundamental EMP and leads to the
appearance of a novel gapless mode of the fundamental EMP. For sufficiently
weak modulation strengths the phase velocity of this novel mode is almost the
same as the group velocity of the edge states but it should be quite smaller
for stronger modulation. We discuss in detail the spatial structure of the
charge density of the renormalized and the novel fundamental EMP's.Comment: 8 pages, 4 figure
Einfluss von Ozon, CO2 und Trockenstress auf das Wachstum und die Pollenproduktion der Beifuß-Ambrosie (Ambrosia artemisiifolia)
Klimaveränderungen beeinflussen das pflanzliche Wachstum und können auch einen Einfluss auf den Pollen haben. Wichtige Faktoren sind dabei erhöhte CO2-Konzentrationen, Trockenstress und Schadstoffbelastungen. Die Pollen der Beifuß-Ambrosie gehören mit zu den stärksten Allergie-Auslösern und beeinflussen die menschliche Gesundheit. In dieser Studie wurde die Beifuß-Ambrosie über die gesamte Vegetationsperiode erhöhten CO2- (700 ppm) und Ozon- (80 ppb) Konzentrationen ausgesetzt. Ferner wurde der Einfluss von Trockenstress unter unterschiedlichen CO2-Konzentrationen untersucht. Erhöhtes CO2 und Trockenstress hatten keinen Einfluss auf die Größe, Form und Oberflächenstruktur des Pollens. Bezüglich morphologischer Parameter resultierte erhöhtes CO2 in einer Zunahme des Stängelwachstums und der Hauptinfloreszenz, sowie vermehrter Pollenproduktion. Trockenstress führte zu einem reduzierten Wachstum des Stängels und der Hauptinfloreszenz und verringerter Pollen-Ausbeute. Erhöhte Ozon-Werte führten tendenziell zu einer geringeren, statistisch jedoch nicht signifikant veränderten Pollenausbeute. Diese Ergebnisse weisen darauf hin, dass Klimaveränderungen die Entwicklung von Ambrosia-Pollen beeinflussen und dadurch auch die öffentliche Gesundheit beeinträchtigen.Stichwörter: Allergie, Infloreszenz, Klimawandel, Luftschadstoff, Stängel, VegetationsperiodeEffects of ozone, CO2 and drought stress on the growth and pollen production of common ragweed (Ambrosia artemisiifolia)Climate change will affect the growth of plants and may also influence the production of pollen. The important factors influencing climate change are increased CO2 concentrations, drought and air pollution. Common ragweed pollen is known to be strongly allergenic, thereby affecting human health. In this study, common ragweed plants were grown over an entire vegetation period under conditions of twice the ambient level of CO2 (700 ppm) and ozone (80 ppm), respectively. Furthermore, the effect of soil drought combined with different CO2 levels was investigated. Scanning electron microscopy showed no change in surface morphology and size of CO2- and drought-treated pollen. Regarding morphological parameters, elevated CO2 resulted in an increased length of the stem and the main inflorescence and higher pollen yields, whereas drought reduced the stem and inflorescence lengths and resulted in a lower pollen yield, a result that was mitigated by elevated CO2. Twice the ambient level of ozone tends to result in a reduced pollen yield. However, this was not statistically significant. These findings support the idea that the conditions of climate change will influence the development of common ragweed pollen, thereby affecting public health.Keywords: Allergy, air pollution, inflorescence, climate change, stem, vegetation perio
Magnetotransport of electrons in quantum Hall systems
Recent theoretical results on magnetotransport of electrons in a 2D system in
the range of moderately strong transverse magnetic fields are reviewed. The
phenomena discussed include: quasiclassical memory effects in systems with
various types of disorder, transport in lateral superlattices,
interaction-induced quantum magnetoresistance, quantum magnetooscillations in
dc and ac transport, and oscillatory microwave photoconductivity.Comment: Mini-review for Proceedings of the DFG Priority Progamme "Quantum
Hall Systems"; to be published in a special issue of Physica Status Solidi
(b); 27 pages, 22 figure
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