Search

Distributed phased array radar networks provide an improved target detection and parameter estimation performance due to extended spatial coverage and multiple observation perspectives. By increasing a network’s baseline, these capabilities can be further enhanced. However, the spatial area that the Rx stations need to cover increases with growing baselines, requiring a high number of Rx beams. This poses a challenge, since the number of receiving channels is often limited by hardware or software. Therefore, designing the Rx beamformer is a key factor for baseline extension and network performance. In this paper, we analyze the use of two different beamformers for a bistatic network configuration: a commonly used sum beam method and a recently proposed eigenbeamformer. The numerical results demonstrate the superiority of the eigenbeamformer in parameter estimation accuracy, resource efficiency and baseline extension ability.

The aim of the study was to characterize the value of combined endoscopy of tracheobronchial tree and oesophagus within 1 session for diagnosis of HIV-associated disorders. Hospitalized HIV-positive patients who underwent combined flexible broncho-oesophagoscopies between 1999 and 2002 in 2 units for infectious diseases were studied retrospectively. 54 HIV patients were analysed; 89% were at stage CDC C, 79% were male, mean age was 40 y. Bronchoscopy led to a diagnosis in 57.4% (95% CI 43.2-70.8). In 40.7%, these were AIDS-defining events (ADE) and 16.7% were general disorders (GD). Oesophagoscopy was diagnostic in 46.3% (95% CI 32.6-60.4). In 35.2% these were ADE, and 11.1% were GD. Patients with pathological oesophagoscopy had a significantly lower CD4 cell count and a higher viral load. There was no association of pathological bronchoscopy with pathological oesophagoscopy regarding ADE. No severe complication was recorded. It is concluded that combined flexible broncho-oesophagoscopy is a valuable and safe method for the diagnosis of HIV-associated disorders. The diagnostic output is highest in patients with advanced disease. A pathological finding in oesophagoscopy cannot be predicted by the presence of bronchoscopic abnormalities. Prospective studies are necessary to confirm these results.

Rhesus-positive and Rhesus-negative persons differ in the presence-absence of highly immunogenic RhD protein on the erythrocyte membrane. The biological function of the RhD molecule is unknown. Its structure suggests that the molecular complex with RhD protein transports NH3 or CO2 molecules across the erythrocyte cell membrane. Some data indicate that RhD positive and RhD negative subjects differ in their tolerance to certain biological factors, including, Toxoplasma infection, aging and fatique. Present cross sectional study performed on 3,130 subjects) showed that Rhesus negative subjects differed in many indices of their health status, including incidences of many disorders. Rhesus negative subjects reported to have more frequent allergic, digestive, heart, hematological, immunity, mental health, and neurological problems. On the population level, a Rhesus-negativity-associated burden could be compensated for, for example, by the heterozygote advantage, but for Rhesus negative subjects this burden represents a serious problem.

Background The aim of this article is to make physicians of all specialties aware of the possible variations of clinical course in human cowpox infection. This has been a matter of current interest since the detection of a first cluster of infections among owners of white pet rats in the Krefeld area in the spring of 2008. Two further cases arose in the Krefeld area in November 2008, and there have since been multiple further reports from various regions in Germany and the neighboring countries.

Interference effects among several commands offered by an experimental text editor were demonstrated. The experiment involved 24 computer novices correcting texts with a computer in several working sessions. The interference effects are interpreted as ‘fan-effects’, similar to those studied with propositional material (Anderson 1976). During the processing of editing tasks, increased latencies for key-strokes were observed with rising degrees of fan. Two sorts of fan degrees were manipulated in the experiment: Firstly, fan-effects arise if the same features of editing tasks occur for different commands (task fan). Secondly, fan-effects also arise if the same user action (e.g. key-stroke) is required for the execution of different commands (key fan). The mapping from task features to command names was varied. Consistent editors were compared to inconsistent ones. In consistent editors the same task features were mapped to the same key-strokes for different commands, while in inconsistent editors the mapping from task features to command keys was random. For consistent editors, interference due to fan is reduced as compared to inconsistent editors. The interference effects, as well as their qualitative dependence on consistency, point to functional equivalences among interference effects as observed here and as studied previously with propositional materials.

n/a