University of Mainz

About: University of Mainz is a education organization based out in Mainz, Rheinland-Pfalz, Germany. It is known for research contribution in the topics: Population & Immune system. The organization has 37673 authors who have published 71163 publications receiving 2497880 citations. The organization is also known as: Johannes Gutenberg-Universität Mainz & Universität Mainz.

Static and dynamic properties of a viscous silica melt

Abstract: We present the results of a large scale molecular dynamics computer simulation in which we investigated the static and dynamic properties of a silica melt in the temperature range in which the viscosity of the system changes from ${O(10}^{\ensuremath{-}2})$ P to ${O(10}^{2})$ P. We show that even at temperatures as high as 4000 K the structure of this system is very similar to the random tetrahedral network found in silica at lower temperatures. The temperature dependence of the concentration of the defects in this network shows an Arrhenius law. From the partial structure factors we calculate the neutron scattering function and find that it agrees very well with experimental neutron scattering data. At low temperatures the temperature dependence of the diffusion constants D shows an Arrhenius law with activation energies which are in very good agreement with the experimental values. With increasing temperature we find that this dependence shows a crossover to one which can be described well by a power law, $D\ensuremath{\propto}(T\ensuremath{-}{T}_{c}{)}^{\ensuremath{\gamma}}$. The critical temperature ${T}_{c}$ is 3330 K and the exponent $\ensuremath{\gamma}$ is close to 2.1. Since we find a similar crossover in the viscosity, we have evidence that the relaxation dynamics of the system changes from a flowlike motion of the particles, as described by the ideal version of mode-coupling theory, to a hoppinglike motion. We show that such a change of the transport mechanism is also observed in the product of the diffusion constant and the lifetime of a Si-O bond or the space and time dependence of the van Hove correlation functions.

Thoracic Endovascular Aortic Repair (TEVAR) for the treatment of aortic diseases: a position statement from the European Association for Cardio-Thoracic Surgery (EACTS) and the European Society of Cardiology (ESC), in collaboration with the European Association of Percutaneous Cardiovascular Interventions (EAPCI)

Abstract: Thoracic endovascular aortic repair (TEVAR) is an emerging treatment modality, which has been rapidly embraced by clinicians treating thoracic aortic disease.1–4 Fundamentally, it is a far less invasive approach than open surgery and its availability and relative ease of application has changed and extended management options in thoracic aortic disease, including in those patients deemed unfit or unsuitable for open surgery. In the operating room, this requires considerable perceptual, cognitive and psychomotor demands on the operators. The dramatic expansion of TEVAR activity has necessarily prompted a requirement to systematically consider the indications, appropriateness, limitations and delivery of this treatment, which has been adopted by many specialties including cardiologists, cardiovascular surgeons, radiologists and vascular surgeons.5 Our task has been to generate a multidisciplinary position statement that supports and advises all clinicians utilizing this technological advance. This document focuses on the main diagnoses—thoracic aortic aneurysm (TAA), thoracic aortic dissection (TAD) of the descending aorta (type B according to the Stanford classification) and thoracic aortic injury (TAI)—indications and applicability of TEVAR and includes information regarding its limitations and complications. It acts as a position statement for both societies that reflects current understanding of thoracic aortic endovascular therapy. ### Evaluation of symptoms and patient status Symptoms in patients with TAA and chronic dissection are rare and non-specific.6,7 New onset of hoarseness or dysphagia may suggest a developing aneurysm in the distal aortic arch and proximal descending aorta. Most asymptomatic cases are discovered incidentally, while symptomatic patients have usually developed complications. Even in patients with acute aortic syndromes, chest pain, back pain and signs of malperfusion are often misinterpreted due to lack of awareness. In cases of clinical suspicion, a computed tomography (CT)-angiography is the diagnostic modality of first choice. ### Multidisciplinary consultation Patient selection should be performed on an individual basis according to anatomy, pathology, comorbidity and …

Search for dark matter and other new phenomena in events with an energetic jet and large missing transverse momentum using the ATLAS detector

Abstract: Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses proton-proton collision data corresponding to an integrated luminosity of 36.1 fb−1 at a centre-of-mass energy of 13 TeV collected in 2015 and 2016 with the ATLAS detector at the Large Hadron Collider. Events are required to have at least one jet with a transverse momentum above 250 GeV and no leptons (e or μ). Several signal regions are considered with increasing requirements on the missing transverse momentum above 250 GeV. Good agreement is observed between the number of events in data and Standard Model predictions. The results are translated into exclusion limits in models with pair-produced weakly interacting dark-matter candidates, large extra spatial dimensions, and supersymmetric particles in several compressed scenarios.

Neanderthal behaviour, diet, and disease inferred from ancient DNA in dental calculus

Abstract: Recent genomic data have revealed multiple interactions between Neanderthals and modern humans, but there is currently little genetic evidence regarding Neanderthal behaviour, diet, or disease. Here we describe the shotgun-sequencing of ancient DNA from five specimens of Neanderthal calcified dental plaque (calculus) and the characterization of regional differences in Neanderthal ecology. At Spy cave, Belgium, Neanderthal diet was heavily meat based and included woolly rhinoceros and wild sheep (mouflon), characteristic of a steppe environment. In contrast, no meat was detected in the diet of Neanderthals from El Sidron cave, Spain, and dietary components of mushrooms, pine nuts, and moss reflected forest gathering. Differences in diet were also linked to an overall shift in the oral bacterial community (microbiota) and suggested that meat consumption contributed to substantial variation within Neanderthal microbiota. Evidence for self-medication was detected in an El Sidron Neanderthal with a dental abscess and a chronic gastrointestinal pathogen (Enterocytozoon bieneusi). Metagenomic data from this individual also contained a nearly complete genome of the archaeal commensal Methanobrevibacter oralis (10.2× depth of coverage)-the oldest draft microbial genome generated to date, at around 48,000 years old. DNA preserved within dental calculus represents a notable source of information about the behaviour and health of ancient hominin specimens, as well as a unique system that is useful for the study of long-term microbial evolution.

Fermionic transport and out-of-equilibrium dynamics in a homogeneous Hubbard model with ultracold atoms

Abstract: The transport measurements of an interacting fermionic quantum gas in an optical lattice provide a direct experimental realization of the Hubbard model—one of the central models for interacting electrons in solids—and give insights into the transport properties of many-body phases in condensed-matter physics.