The Effect of Fluctuations on the QCD Critical Point in a Finite Volume

We investigate the effect of a finite volume on the critical behavior of the theory of the strong interaction (QCD) by means of a quark-meson model for two quark flavors. In particular, we analyze the effect of a finite volume on the location of the critical point in the phase diagram existing in our model. In our analysis, we take into account the effect of long-range fluctuations with the aid of renormalization group techniques. We find that these quantum and thermal fluctuations, absent in mean-field studies, play an import role for the dynamics in a finite volume. We show that the critical point is shifted towards smaller temperatures and larger values of the quark chemical potential if the volume size is decreased. This behavior persists for antiperiodic as well as periodic boundary conditions for the quark fields as used in many lattice QCD simulations.Comment: 9 pages, 2 figures, 1 tabl

Agglomeration and filtration of colloidal suspensions with DVLO interactions in simulation and experiment

Cake filtration is a widely used solid-liquid separation process. However, the high flow resistance of the nanoporous filter cake lowers the efficiency of the process significantly. The structure and thus the permeability of the filter cakes depend on the compressive load acting on the particles, the particles size, and the agglomeration of the particles. The latter is determined by the particle charge and the ionic strength of the suspension, as described by the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. In this paper, we propose a combined stochastic rotation dynamics (SRD) and molecular dynamics (MD) methodology to simulate the cake formation. The simulations give further insight into the dependency of the filter cakes' structure on the agglomeration of the particles, which cannot be accessed experimentally. The permeability, as investigated with lattice Boltzmann (LB) simulations of flow through the discretized cake, depends on the particle size and porosity, and thus on the agglomeration of the particles. Our results agree qualitatively with experimental data obtained from colloidal boehmite suspensions.Comment: revised version, 30 pages, 11 figures, 62 reference

Generic Role Model for the Systematic Development of Internal AI-based Services in Manufacturing

Latest research has shown that one challenge for the development and implementation of Industrial AI-based services is uncertainty of roles and responsibilities. To address this challenge, we developed a generic role model for the systematic development of AI-based services in manufacturing. The role model describes which roles are necessary within the development process of an Industrial AI-based service. Thereby, a distinction is made whether the roles are assigned to the “core team”, the “extended team” or participate in “supporting roles”. Furthermore, the model shows whether the roles are involved in the “Ideation” phase, the “Requirements and design” phase, the “Test” phase or the “Implementation and roll-out” phase. Based on desktop research, semi-structured interviews and expert workshops we identified 22 roles that are relevant to the development and implementation of Industrial AI-based services

On the Phase Structure of QCD in a Finite Volume

The chiral phase transition in QCD at finite chemical potential and temperature can be characterized for small chemical potential by its curvature and the transition temperature. The curvature is accessible to QCD lattice simulations, which are always performed at finite pion masses and in finite simulation volumes. We investigate the effect of a finite volume on the curvature of the chiral phase transition line. We use functional renormalization group methods with a two flavor quark-meson model to obtain the effective action in a finite volume, including both quark and meson fluctuation effects. Depending on the chosen boundary conditions and the pion mass, we find pronounced finite-volume effects. For periodic quark boundary conditions in spatial directions, we observe a decrease in the curvature in intermediate volume sizes, which we interpret in terms of finite-volume quark effects. Our results have implications for the phase structure of QCD in a finite volume, where the location of a possible critical endpoint might be shifted compared to the infinite-volume case.Comment: 11 pages, 3 figures, 4 tables; minor text corrections, one figure added, appendix added, references added, matches PLB versio

Effect of voluntary exercise on number and volume of cardiomyocytes and their mitochondria in the mouse left ventricle

Voluntary exercise (VE) has a beneficial influence on the heart and mean lifespan. The present study evaluates structural adaptations of cardiomyocytes and their mitochondria due to VE by new, unbiased stereological methods. Female, 7-9-week-old mice were randomly assigned to a control (CG, n=7) or VE group (EG, n=7). EG animals were housed in cages with free access to a running wheel and had a mean running distance of 6.7 (1.8)km per day. After 4weeks, the hearts of all mice were processed for light and electron microscopy. We estimated the number and volume of cardiomyocytes by the disector method and the number and volume of mitochondria by estimation of the Euler number. In comparison to CG, VE did not have an effect on the myocardial volume of the left ventricle (CG: 93 (10), EG: 103 (17) (mm3)), the number of cardiomyocytes (CG: 2.81 (0.27), EG: 2.82 (0.43) (×106)) and their number-weighted mean volume. However, the composition of the cardiomyocytes changed due to VE. The total volume of mitochondria (CG: 21.8 (4.9), EG: 32.2 (4.3) (mm3), P<0.01) and the total number (CG: 3.76 (0.44), EG: 7.02 (1.13) (×1010), P<0.001) were significantly higher in EG than in CG. The mean number-weighted mitochondrial volume was smaller in EG than in CG (P<0.05). In summary, VE does not alter ventricular volume nor cardiomyocyte volume or number but the oxidative capacity of cardiomyocytes by an increased mitochondrial number and total volume in the left ventricle. These structural changes may participate in the beneficial effects of V

Linking the Quark Meson Model with QCD at High Temperature

We model the transition of a system of quarks and gluons at high energies to a system of quarks and mesons at low energies in a consistent renormalization group approach. Flow equations interpolate between the physics of the high-temperature degrees of freedom and the low-temperature dynamics at a scale of 1 GeV. We also discuss the dependence of the equation of state on baryon density and compare our results with recent lattice gauge simulations.Comment: 11 pages, 4 figures additional discussion of the second order phase transitio

Impact of treatment planning target volumen (PTV) size on radiation induced diarrhoea following selenium supplementation in gynecologic radiation oncology - a subgroup analysis of a multicenter, phase III trial

Background: In a previous analysis (Int J Radiat Oncol Biol Phys 70:828-835,2010), we assessed whether an adjuvant supplementation with selenium (Se) improves Se status and reduces the radiation-induced side-effects of patients treated by adjuvant radiotherapy (RT) for cervical and uterine cancer. Now, a potential relation between the planning target volume (PTV) of the RT and the Se effect concerning radiation induced diarrhoea was evaluated in detail. Methods: Whole blood Se concentrations had been measured in patients with cervical (n=11) and uterine cancer (n=70) after surgical treatment, during, and at the end of RT. Patients with initial Se concentrations of less than 84 μg/l were categorized as Se-deficient and randomized before RT to receive Se (as sodium selenite) per os on the days of RT, or to receive no supplement during RT. Diarrhoea was graded according to the Common Toxicity Criteria system (CTC, Version 2a). The evaluation of the PTV of the RT was ascertained with the help of a specialised computer-assisted treatment planning software used for radiation planning procedure. Results: A total of 81 patients had been randomized for the initial supplementation study, 39 of which received Se [selenium group, SeG] and 42 serving as controls [control group, CG]. Mean Se levels did not differ between SeG and CG upon study initiation, but were significantly higher in the SeG compared to the CG at the end of RT. The actuarial incidence of at least CTC 2 radiation induced diarrhoea in the SeG was 20.5% compared to 44.5% in the CG (p=0.04). The median PTV in both groups was 1302 ml (916–4608). With a PTV of 1302 ml (n=40) the actuarial incidence of at least CTC 2 diarrhoea in the SeG was 19.1% (4 of 21 patients) versus 52.6% (10 of 19 patients) in the CG (p=0.046). Conclusions: Se supplementation during RT was effective to improve blood Se status in Se-deficient cervical and uterine cancer patients, and reduces episodes and severity of RT-induced diarrhoea. This effect was most pronounced and significant in patients with large PTV (> 1302 ml)

No Accumulation of Transposable Elements in Asexual Arthropods.

Transposable elements (TEs) and other repetitive DNA can accumulate in the absence of recombination, a process contributing to the degeneration of Y-chromosomes and other nonrecombining genome portions. A similar accumulation of repetitive DNA is expected for asexually reproducing species, given their entire genome is effectively nonrecombining. We tested this expectation by comparing the whole-genome TE loads of five asexual arthropod lineages and their sexual relatives, including asexual and sexual lineages of crustaceans (Daphnia water fleas), insects (Leptopilina wasps), and mites (Oribatida). Surprisingly, there was no evidence for increased TE load in genomes of asexual as compared to sexual lineages, neither for all classes of repetitive elements combined nor for specific TE families. Our study therefore suggests that nonrecombining genomes do not accumulate TEs like nonrecombining genomic regions of sexual lineages. Even if a slight but undetected increase of TEs were caused by asexual reproduction, it appears to be negligible compared to variance between species caused by processes unrelated to reproductive mode. It remains to be determined if molecular mechanisms underlying genome regulation in asexuals hamper TE activity. Alternatively, the differences in TE dynamics between nonrecombining genomes in asexual lineages versus nonrecombining genome portions in sexual species might stem from selection for benign TEs in asexual lineages because of the lack of genetic conflict between TEs and their hosts and/or because asexual lineages may only arise from sexual ancestors with particularly low TE loads

Assessment of left atrial functional parameters using a novel dedicated analysis tool for real-time three-dimensional echocardiography: validation in comparison to magnetic resonance imaging

Real-time three-dimensional echocardiography (RT3DE) is superior to two-dimensional echocardiography in assessing left atrial (LA) parameters, but to date algorithms developed for the left ventricle were applied due to a lack of dedicated LA software. In addition, no data are available on RT3DE assessment of active atrial contraction. The aim of this study was to validate a novel RT3DE analysis tool specifically dedicated to evaluate the LA. Cardiac magnetic resonance imaging (MRI) served as standard of reference. Fifty-five patients scheduled for pulmonary vein isolation underwent cardiac MRI and RT3DE. On ultrasound image datasets, a dynamic polyhedron model of the LA was generated from which LA maximum and minimum volumes (LAmax and LAmin), passive atrial emptying fraction (LAEF), and active atrial ejection fraction (LAEFtrue) were derived and compared to values obtained from cardiac MRI. High intraclass correlations between RT3DE and MRI were found for LAmax (r=0.94, p<0.001), LAmin (r=0.95, p<0.001), LAEF (r=0.92, p<0.001), and LAEFtrue (r=0.87, p<0.001). Similarly, Bland-Altman analysis revealed narrow limits of agreement for LAmax (−28.6 to 14.1ml), LAmin (−26.8 to 12.4ml), LAEF (−11.2 to 14.9%), and LAEFtrue (−10.6 to 6.8%). LAmax, LAmin and LAEFtrue were measured significantly (p<0.05) lower by RT3DE (111±38ml vs. 118±39ml, 73±38ml vs. 80±41ml, and 23±14% vs. 27±14%, respectively). Interobserver and intraobserver RT3DE measurements correlated closely. RT3DE using a novel dedicated software tool is valid, accurate and reproducible for assessing LA dimensional and functional parameters. This study corroborates previous reports and extends its validity to the assessment of active LA contractio