228 research outputs found
Freezing of parallel hard cubes with rounded edges
The freezing transition in a classical three-dimensional system of parallel
hard cubes with rounded edges is studied by computer simulation and
fundamental-measure density functional theory. By switching the rounding
parameter s from zero to one, one can smoothly interpolate between cubes with
sharp edges and hard spheres. The equilibrium phase diagram of rounded parallel
hard cubes is computed as a function of their volume fraction and the rounding
parameter s. The second order freezing transition known for oriented cubes at s
= 0 is found to be persistent up to s = 0.65. The fluid freezes into a
simple-cubic crystal which exhibits a large vacancy concentration. Upon a
further increase of s, the continuous freezing is replaced by a first-order
transition into either a sheared simple cubic lattice or a deformed
face-centered cubic lattice with two possible unit cells: body-centered
orthorhombic or base-centered monoclinic. In principle, a system of parallel
cubes could be realized in experiments on colloids using advanced synthesis
techniques and a combination of external fields.Comment: Submitted to JC
Testing expert groups for a habitat suitability model for the lynx Lynx lynx in the Swiss Alps
Importance of dispersal for the expansion of a Eurasian lynx Lynx lynx population in a fragmented landscape
Dispersal allows recolonization of previous areas of habitat following severe depression of a population but the significance of this is not clear in felids. There is little evidence to support the general belief that subadult felids will colonize new areas, although this isa crucial assumption in reintroduction or recovery projects. Eurasian lynx Lynx lynx were reintroduced into the Swiss Alps and have subsequently spread over part of their potential range but the expansion halted in the mid 1980s. We postulated that high lynx densities would lead to an expansion of the population, and to assess the potential of this population to expand we compared the dispersal characteristics of 22 subadults from the north-west Swiss Alps, where an increase in lynx abundance occurred from 1995 onwards, to 17 individuals from the Jura Mountains, an area with a lower lynx density. Dispersal data came mainly from radio-telemetry. Dispersal rates and distances for subadults that completed dispersal were lower in the north-west Swiss Alps than in the Jura Mountains. In general, subadults exhibited little ability to cross major barriers such as highways. The hypothesis that high density alone will foster theexpansion of the population was therefore not confirmed. This has consequences for the reintroduction and recovery of carnivores in fragmented landscapes. Toestablish only one strong source population may notbe an optimal strategy, and population nuclei shouldtherefore be founded in several neighbouring patche
Comparison of different lattice definitions of the topological charge
We present a comparison of different definitions of the topological charge on
the lattice, using a small-volume ensemble with 2 flavours of dynamical twisted
mass fermions. The investigated definitions are: index of the overlap Dirac
operator, spectral projectors, spectral flow of the Hermitian Wilson-Dirac
operator and field theoretic with different kinds of smoothing of gauge fields
(HYP and APE smearings, gradient flow, cooling). We also show some results on
the topological susceptibility.Comment: 7 pages, 2 figures, presented at the 32nd International Symposium on
Lattice Field Theory (Lattice 2014), 23-28 June 2014, Columbia University,
New York, NY, US
Vascular dysfunction in COVID-19 patients: update on SARS-CoV-2 infection of endothelial cells and the role of long non-coding RNAs
Although COVID-19 is primarily a respiratory disease, it may affect also the cardiovascular system. COVID-19 patients with cardiovascular disorder (CVD) develop a more severe disease course with a significantly higher mortality rate than non-CVD patients. A common denominator of CVD is the dysfunction of endothelial cells (ECs), increased vascular permeability, endothelial-to-mesenchymal transition, coagulation, and inflammation. It has been assumed that clinical complications in COVID-19 patients suffering from CVD are caused by SARS-CoV-2 infection of ECs through the angiotensin-converting enzyme 2 (ACE2) receptor and the cellular transmembrane protease serine 2 (TMPRSS2) and the consequent dysfunction of the infected vascular cells. Meanwhile, other factors associated with SARS-CoV-2 entry into the host cells have been described, including disintegrin and metalloproteinase domain-containing protein 17 (ADAM17), the C-type lectin CD209L or heparan sulfate proteoglycans (HSPG). Here, we discuss the current data about the putative entry of SARS-CoV-2 into endothelial and smooth muscle cells. Furthermore, we highlight the potential role of long non-coding RNAs (lncRNAs) affecting vascular permeability in CVD, a process that might exacerbate disease in COVID-19 patients
Differently Shaped Hard Body Colloids in Confinement: From passive to active particles
We review recent progress in the theoretical description of anisotropic hard
colloidal particles. The shapes considered range from rods and dumbbells to
rounded cubes, polyhedra and to biaxial particles with arbitrary shape. Our
focus is on both static and dynamical density functional theory and on computer
simulations. We describe recent results for the structure, dynamics and phase
behaviour in the bulk and in various confining geometries, e.g. established by
two parallel walls which reduce the dimensionality of the system to two
dimensions. We also include recent theoretical modelling for active particles,
which are autonomously driven by some intrinsic motor, and highlight their
fascinating nonequilibrium dynamics and collective behaviour.Comment: 15 pages, 6 figures, EPJ ST (accepted
Quantitative evaluation of the beneficial effects in the mdx mouse of epigallocatechin gallate, an antioxidant polyphenol from green tea
In two separate previous studies, we reported that subcutaneous (sc) or oral administration of (−)-epigallocatechin-3-gallate (EGCG) limited the development of muscle degeneration of mdx mice, a mild phenotype model for Duchenne muscular dystrophy (DMD). However, it was not possible to conclude which was the more efficient route of EGCG administration because different strains of mdx mice, periods of treatment and methods of assessment were used. In this study, we investigated which administration routes and dosages of EGCG are the most effective for limiting the onset of dystrophic lesions in the same strain of mdx mice and applying the same methods of assessment. Three-week-old mdx mice were injected sc for 5weeks with either saline or a daily average of 3 or 6mg/kg EGCG. For comparison, age-matched mdx mice were fed for 5weeks with either a diet containing 0.1% EGCG or a control diet. The effects of EGCG were assessed quantitatively by determining the activities of serum muscle-derived creatine kinase, isometric contractions of triceps surae muscles, integrated spontaneous locomotor activities, and oxidative stress and fibrosis in selected muscles. Oral administration of 180mg/kg/day EGCG in the diet was found the most effective for significantly improving several parameters associated with muscular dystrophy. However, the improvements were slightly less than those observed previously for sc injection started immediately after birth. The efficacy of EGCG for limiting the development of dystrophic muscle lesions in mice suggests that EGCG may be of benefit for DMD patient
High precision and high throughput surface structuring by synchronizing mechanical axes with an ultra short pulsed laser system in MOPA arrangement
Erratum to “The Challenge of Triaging Chest Pain Patients: The Bernese University Hospital Experience”
Accurate diagnosis of the causes of chest pain and dyspnea remain challenging. In this preliminary observational study with a 5-year follow-up, we attempted to find a simplified approach to selecting patients with chest pain needing immediate care based on the initial evaluation in ED. During a 24-month period were randomly selected 301 patients and a conditional inference tree (CIT) was used as the basis of the prognostic rule. Common diagnoses were musculoskeletal chest pain (27%), ACS (19%) and panic attack (12%). Using variables of ACS symptoms we estimated the likelihood of ACS based on a CIT to be high at 91% (32), low at 4% (198) and intermediate at 20.5–40% in (71) patients. Coronary catheterization was performed within 24 hours in 91% of the patients with ACS. A culprit lesion was found in 79%. Follow-up (median 4.2 years) information was available for 70% of the patients. Of the 164 patients without ACS who were followed up, 5 were treated with revascularization for stable angina pectoris, 2 were treated with revascularization for myocardial infarction, and 25 died. Although a simple triage decision tree could theoretically help to efficient select patients needing immediate care we need also to be vigilant for those presenting with atypical symptoms
Ultra-high-precision surface structuring by synchronizing a galvo scanner with an ultra-short-pulsed laser system in MOPA arrangement
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