Modelling categorical covariates in Bayesian disease mapping by partition structures

We consider the problem of mapping the risk from a disease using a series of regional counts of observed and expected cases, and information on potential risk factors. To analyse this problem from a Bayesian viewpoint we propose a methodology, which extends a spatial partition model by including categorical covariate information. Such an extension allows to detect clusters in the residual variation, reflecting further, possibly unobserved, covariates. The methodology is implemented by means of reversible jump Markov chain Monte Carlo sampling. An application is presented, in order to illustrate and compare our proposed extensions with a purely spatial partition model. Here we analyse a well-known dataset on lip cancer incidence in Scotland

Film thickness measurements in a running hydrostatic unit using ultrasound

The present paper describes the measurement of the oil film thickness in the range of a few micrometers in an operating hydrostatic unit using ultrasound. The investigated tribological system consists of a rotating steel cylinder block and a stationary bi-metal valve plate under static and hydrodynamic lubrication. The film thickness has been recorded in a wide range of operating conditions, pressure between 100 to 300 bar and rotational speed between 500 and 3000 rpm, to support a deeper understanding of the system. Temperature sensors were implemented next to the ultrasound sensors to compensate the ultrasound signal amplitude and phase change due to temperature dependent acoustic impedances. To confirm the results, especially the presence of deliberate zero-film conditions, wear profiles of the running surface were taken. The ultrasound technique also allows the real-time observation of film thickness oscillations with shaft and piston frequency. Steady-state measurements confirm the system behavior observed in transient operation and zero-film conditions with respect to hardware configuration were detected. The findings will be utilized to support current product development activities and to validate and improve simulation models used for film thickness predictions

The effect of exercise hyperpnea on gross efficiency and anaerobic capacity estimates during a 3-min cycle time trial

This study aimed to analyze the effect of exercise-induced hyperpnea on gross efficiency (GE) and anaerobic capacity estimates during a self-paced 3-min supramaximal cycle time trial (TT). Fourteen highly-trained male cyclists performed 7×4-min submaximal stages, a 6-min passive rest, a 3-min TT, a 5-min passive rest, and a 6-min submaximal stage. Three models were based on the 7×4-min linear regression extrapolation method, using (1) the conventional model (7-YLIN); (2) the same 7-YLIN model but correcting for the additional ventilatory cost (i.e., hyperpnea) (7-YLIN-V-cor); and, (3) accounting for linearly declining GE during the TT (7-YLIN-D). The other three models were based on GE from the last submaximal stage, using the conventional model (GELAST) and the same modifications as described for 7+YLIN, i.e., (1) GELAST, (2) GELAST-V-cor, and (3) GELAST-D. The GELAST model generated 18% higher values of anaerobic capacity than the 7-YLIN model (P<0.05). During the TT, the hyperpnea corrected model (i.e., 7-YLIN-V-cor or GELAST-V-cor) generated, compared to the respective conventional model (i.e., 7-YLIN or GELAST), ~0.7 percentage points lower GE and ~11% higher anaerobic capacity (all, P<0.05). The post-TT GE was 1.9 percentage points lower (P<0.001) and the 7-YLIN-D or GELAST-D model generated, compared to the respective conventional model, a lower GE (~1.0 percentage points) and ~17% higher anaerobic capacity during the TT (all, P<0.05). In conclusion, the correction for a declining GE due to hyperpnea during a supramaximal TT resulted in an increased required total metabolic rate and anaerobic energy expenditure compared to the conventional models

Enzymfreisetzung und Aktivierung der Kallikrein-Kinin-Systeme bei experimenteller Pankreatitis

Das klinische Bild der akuten Pankreatitis wird entscheidend durch die sekundäre Schädigung von Herz-Kreislauf-System, Lunge und Niere bestimmt. Ziel der vorliegenden Untersuchung war es, durch Messungen in venösem Pankreasblut, Pankreaslymphe und Peritonealexsudat die Kompartimente zu bestimmen, über die die systemischen Schädigungen vermittelt werden. An anästhesierten Schweinen wurden die systemischen, hämodynamischen Parameter durch gesteuerte Volumentherapie konstant gehalten. Die Schweine wurden randomisiert der Kontrollgruppe (n = 9) oder einer der Pankreatitisgruppen zugeteilt (jeweils n = 10). Die Pankreatitis wurde durch Infusion von freier Fettsäure in die Pankreasarterien (FFS) oder durch Infusion einer 5%igen Natrium-Taurocholat-Lösung retrograd in den Pankreasgang (NaT) ausgelöst. Nach Isolation des Pankreas wurde venöses Pankreasblut, Pankreaslymphe und Peritonealexsudat gewonnen und die Aktivität von Lipase, Phospholipase A und Plasmaprokallikrein sowie die Konzentration von Organkallikrein und Kininogen bestimmt. In beiden Pankreatitismodellen fand sich ein Anstieg der Enzymaktivitäten. Die höchsten Aktivitäten fanden sich im Peritonealexsudat (Phospholipase A nach 40 min: Kontrolle 10,0 U/1, NaT 72,2 U/1). In beiden Pankreatitismodellen fanden sich außerdem Hinweise für eine Aktivierung des Organkallikrein-Kinin-Systems durch den Anstieg der Organkallikreinkonzentration und den Abfall der Gesamtkininogenkonzentration. Die stärksten Veränderungen fanden sich wieder im Peritonealexsudat (Organkallikrein nach 40 min: Kontrolle 14,7 ng/ml, NaT 452 ng/ml).The clinical course of acute pancreatitis is strongly influenced by secondary cardiac, pulmonary and renal damage. The aim of the present study was to gather information about the compartment promoting the systemic damage. Therefore the activity of lipase, phospholipase A and plasmaprokallikrein and the concentration of tissue kallikrein and kininogen were measured in portal venous blood, pancreatic lymph and peritoneal exudate. Anaesthetized pigs were subjected to fluid resuscitation to keep systemic haemodynamic parameters constant. The pancreas was isolated in situ. The pigs were randomly assigned to a control group (n = 9) or one of the two pancreatitis groups (n = 10 each). Pancreatitis was induced by i.a. infusion of free fatty acid (FFS) or retrograde infusion of 5 % sodium taurocholate intraductally (NaT). In both pancreatitis groups the activity of lipase and phospholipase A increased. The most pronounced changes were seen in the peritoneal exsudate (phospholipase A activity 40 min after induction: control 10.0 U/1, NaT 72.2 U/1). In both pancreatitis groups there was evidence for activation of the tissue kallikreinkinin system in the form of an increase in the kallikrein concentration and a decrease in the kininogen concentration. Again the changes were most pronounced in the peritoneal exsudate (tissue kallikrein 40 min after induction: control 14.7 ng/ml, NaT 452 ng/ml)

Light-induced translation of motorized molecules on a surface

Molecular machines are a key component in the vision of molecular nanotechnology and have the potential to transport molecular species and cargo on surfaces. The motion of such machines should be triggered remotely, ultimately allowing a large number of molecules to be propelled by a single source, with light being an attractive stimulus. Here, we report upon the photoinduced translation of molecular machines across a surface by characterizing single molecules before and after illumination. Illumination of molecules containing a motor unit results in an enhancement in the diffusion of the molecules. The effect vanishes if an incompatible photon energy is used or if the motor unit is removed from the molecule, revealing that the enhanced motion is due to the presence of the wavelength-sensitive motor in each molecule

Metal-Insulator Transition in a Disordered Two-Dimensional Electron Gas in GaAs-AlGaAs at zero Magnetic Field

A metal-insulator transition in two-dimensional electron gases at B=0 is found in Ga(Al)As heterostructures, where a high density of self-assembled InAs quantum dots is incorporated just 3 nm below the heterointerface. The transition occurs at resistances around h/e^2 and critical carrier densities of 1.2 10^11cm^-2. Effects of electron-electron interactions are expected to be rather weak in our samples, while disorder plays a crucial role.Comment: 4 pages, 3 figures, 21 reference