Publications by authors named "VOIT K"

Unlike traditional base materials such as concrete or masonry, there are no guidelines for rock as a base material for post-installed anchors. The varying rock properties (e.g.

View Article and Find Full Text PDF

Health crises such as the current COVID-19 pandemic pose challenges to the conduct of clinical studies. Aspects of research ethics, such as obtaining informed consent (IC), can be complicated. We are concerned with whether or not the proper IC procedures were followed in the context of clinical studies at Ulm University in the years 2020 to 2022.

View Article and Find Full Text PDF

To determine and compare the measurement uncertainty of different geological-geotechnical testing methods, numerous test locations were selected in a hard rock quarry. Measurements were carried out along two vertical measurement lines perpendicular to the mining levels of an existing exploration. Along these lines, the rock quality basically varies due to weathering (decreasing influence with increasing distance from the original ground surface), but also due to the influence of the geological-tectonic conditions on site.

View Article and Find Full Text PDF

Introduction: There is currently no binding, internationally accepted and successful approach to ensure global equitable access to healthcare during a pandemic. The aim of this ethical analysis is to bring into the discussion a legally regulated vaccine allocation as a possible strategy for equitable global access to vaccines. We focus our analysis on COVAX (COVID-19 Vaccines Global Access) and an existing EU regulation that, after adjustment, could promote global vaccine allocation.

View Article and Find Full Text PDF

Advances in head-mounted microscopes have enabled imaging of neuronal activity using genetic tools in freely moving mice but these microscopes are restricted to recording in minimally lit arenas and imaging upper cortical layers. Here we built a 2-g, three-photon excitation-based microscope, containing a z-drive that enabled access to all cortical layers while mice freely behaved in a fully lit environment. The microscope had on-board photon detectors, robust to environmental light, and the arena lighting was timed to the end of each line-scan, enabling functional imaging of activity from cortical layer 4 and layer 6 neurons expressing jGCaMP7f in mice roaming a fully lit or dark arena.

View Article and Find Full Text PDF

Forming a complete picture of the relationship between neural activity and skeletal kinematics requires quantification of skeletal joint biomechanics during free behavior; however, without detailed knowledge of the underlying skeletal motion, inferring limb kinematics using surface-tracking approaches is difficult, especially for animals where the relationship between the surface and underlying skeleton changes during motion. Here we developed a videography-based method enabling detailed three-dimensional kinematic quantification of an anatomically defined skeleton in untethered freely behaving rats and mice. This skeleton-based model was constrained using anatomical principles and joint motion limits and provided skeletal pose estimates for a range of body sizes, even when limbs were occluded.

View Article and Find Full Text PDF

Sensory signals are transmitted via the thalamus primarily to layer 4 (L4) of the primary sensory cortices. While information about average neuronal connectivity in L4 is available, its detailed higher-order circuit structure is not known. Here, we used three-dimensional electron microscopy for a connectomic analysis of the thalamus-driven inhibitory network in L4.

View Article and Find Full Text PDF

Natural stone constructions for the protection of slopes, banks and riverbeds are widely used in infrastructure engineering. These structures are made of stacked natural stones, which can be placed loosely on top of each other. Additionally, their bond behavior can be improved by using concrete mortar to fill the joints between the stones.

View Article and Find Full Text PDF
Article Synopsis
  • Mice have a large visual field that is stabilized by the vestibular ocular reflex (VOR), allowing them to detect predators and track prey effectively.
  • Researchers developed a method to digitally reconstruct the visual environment of freely moving mice during prey capture tasks, isolating visual input and analyzing head and eye movements.
  • The study found that prey images consistently fall in a specific area of the stabilized visual field that minimizes motion blur, corresponding to a region with a high density of specialized retinal cells responsible for processing motion.
View Article and Find Full Text PDF

In the case of fastenings on rock, as a result of the variability, it is quite difficult to make a preliminary assessment of the load-bearing capacity of rock as a base material. This paper therefore investigates which rock parameters next to an anchor position have an influence on the load-bearing capacity. For this purpose, tests are carried out on post-installed anchors in different lithologies in eastern Austria.

View Article and Find Full Text PDF

This paper aims to analyze the ethical challenges in experimental drug use during the early stage of the COVID-19 pandemic, using Germany as a case study. In Germany uniform ethical guidelines were available early on nationwide, which was considered as desirable by other states to reduce uncertainties and convey a message of unity. The purpose of this ethical analysis is to assist the preparation of future guidelines on the use of medicines during public health emergencies.

View Article and Find Full Text PDF

We designed a head-mounted three-photon microscope for imaging deep cortical layer neuronal activity in a freely moving rat. Delivery of high-energy excitation pulses at 1,320 nm required both a hollow-core fiber whose transmission properties did not change with fiber movement and dispersion compensation. These developments enabled imaging at >1.

View Article and Find Full Text PDF

Beam parameters of a probing laser source in an optical riblet sensor are studied by considering the high demands on a sensors' precision and reliability for the determination of deviations of the geometrical shape of a riblet. Mandatory requirements, such as minimum intensity and light polarization, are obtained by means of detailed inspection of the optical response of the riblet using ray and wave optics; the impact of wavelength is studied. Novel measures for analyzing the riblet shape without the necessity of a measurement with a reference sample are derived; reference values for an ideal riblet structure obtained with the optical riblet sensor are given.

View Article and Find Full Text PDF

Interferometry and holography are two domains that are based on observation and recording of interference fringes from two light beams. While the aim of the first technique is to reveal and map the phase difference of two wave fronts, the main task of the second technique is to reconstruct one of the two recording waves via diffraction of the other wave from the recorded fringe pattern (hologram). To create fringes, mutually coherent waves from the same laser are commonly used.

View Article and Find Full Text PDF

Introduction: Previous research undertaken in the Northern Territory of Australia has identified interest among nurses in engaging in the active workforce post-retirement. Relatively little is known about which nurses are interested in such engagement, and the types of work arrangements that might be of interest. This study aims to provide an enhanced understanding of the retirement plans and post-retirement employment intentions of nurses and midwives living and working in the Northern Territory (NT) of Australia.

View Article and Find Full Text PDF

The problem of diffraction of an electromagnetic wave by a thick hologram grating can be solved by the famous Kogelnik's coupled-wave theory (CWT) to a very high degree of accuracy. We confirm this finding by comparing the CWT and the exact result for a typical example and propose an explanation in terms of perturbation theory. To this end we formulate the problem of diffraction as a matrix problem following similar well-known approaches, especially rigorous coupled-wave theory (RCWT).

View Article and Find Full Text PDF

Holographic spectroscopy is highlighted as a powerful tool for the analysis of photosensitive materials with pronounced alterations of the complex permittivity over a broad range in the visible spectrum, due to the advances made both in the fields of advanced holographic media and highly tunable lasers systems. To analytically discuss consequences for in- and off-Bragg reconstruction, we revised Kogelnik's coupled wave theory strictly on the basis of complex permittivities. We extended it to comply with modern experimental parameters such as out-of-phase mixed holograms and highly modulated gratings.

View Article and Find Full Text PDF

Diffraction efficiency, relaxation behavior and dependence on pump-beam intensity of small-polaron based holograms are studied in thermally reduced, nominally undoped lithium niobate in the visible spectrum (λ = 488 nm). The pronounced phase gratings with diffraction efficiency up to η = (10.8 ± 1.

View Article and Find Full Text PDF

Introduction: Many countries are facing an ageing of the nursing workforce and increasing workforce shortages. This trend is due to members of the 'baby boomer' generation leaving the workforce for retirement and a declining pool of younger people entering the nursing profession. New approaches to engaging older nurses in the workforce are becoming common in nursing globally but have yet to be adapted to remote contexts such as the Northern Territory (NT) of Australia.

View Article and Find Full Text PDF

In single crystals of the DNA nucleotide 2'deoxyguanosine-5'phosphate (5'dGMP) X- or gamma-irradiated at 4.2 K or 15 K, two primary radical species can be discriminated and assigned to the cation and anion of the guanine base, G(+) and G(-). Both species are unstable.

View Article and Find Full Text PDF