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Radiographic imaging with x-rays and protons is an omnipresent tool in basic research and applications in industry, material science and medical diagnostics. The information contained in both modalities can often be valuable in principle, but difficult to access simultaneously. Laser-driven solid-density plasma-sources deliver both kinds of radiation, but mostly single modalities have been explored for applications. Their potential for bi-modal radiographic imaging has never been fully realized, due to problems in generating appropriate sources and separating image modalities. Here, we report on the generation of proton and x-ray micro-sources in laser-plasma interactions of the focused Texas Petawatt laser with solid-density, micrometer-sized tungsten needles. We apply them for bi-modal radiographic imaging of biological and technological objects in a single laser shot. Thereby, advantages of laser-driven sources could be enriched beyond their small footprint by embracing their additional unique properties, including the spectral bandwidth, small source size and multi-mode emission.

Femtosecond (fs) x-ray pulses are a key tool to study the structure and dynamics of matter on its natural length and time scale. To complement radio-frequency accelerator-based large-scale facilities, novel laser-based mechanisms hold promise for compact laboratory-scale x-ray sources. Laser-plasma driven undulator radiation in particular offers high peak-brightness, optically synchronized few-fs pulses reaching into the few-nanometer (nm) regime. To date, however, few experiments have successfully demonstrated plasma-driven undulator radiation. Those that have, typically operated at single and comparably long wavelengths. Here we demonstrate plasma-driven undulator radiation with octave-spanning tuneability at discrete wavelengths reaching from 13 nm to 4 nm. Studying spontaneous undulator radiation is an important step towards a plasma-driven free-electron laser. Our specific setup creates a photon pulse, which closely resembles the plasma electron bunch length and charge profile and thus might enable novel methods to characterize the longitudinal electron phase space.

Bovine respiratory disease (BRD) is the leading cause of mortality and antimicrobial drug (AMD) use in weaned dairy heifers. Limited information is available regarding antimicrobial resistance (AMR) in respiratory bacteria in this population. This study determined AMR gene presence in 326 respiratory isolates (Pasteurella multocida, Mannheimia haemolytica, and Histophilus somni) from weaned dairy heifers using whole genome sequencing. Concordance between AMR genotype and phenotype was determined. Twenty-six AMR genes for 8 broad classes of AMD were identified. The most prevalent, medically important AMD classes used in calf rearing, to which these genes predict AMR among study isolates were tetracycline (95%), aminoglycoside (94%), sulfonamide (94%), beta-lactam (77%), phenicol (50%), and macrolide (44%). The co-occurrence of AMR genes within an isolate was common; the largest cluster of gene co-occurrence encodes AMR to phenicol, macrolide, elfamycin, β-lactam (cephalosporin, penam cephamycin), aminoglycoside, tetracycline, and sulfonamide class AMD. Concordance between genotype and phenotype varied (Matthew’s Correlation Coefficient ranged from −0.57 to 1) by bacterial species, gene, and AMD tested, and was particularly poor for fluoroquinolones (no AMR genes detected) and ceftiofur (no phenotypic AMR classified while AMR genes present). These findings suggest a high genetic potential for AMR in weaned dairy heifers; preventing BRD and decreasing AMD reliance may be important in this population.

Ultrafast pump–probe experiments open the possibility to track fundamental material behaviour, such as changes in electronic configuration, in real time. To date, most of these experiments are performed using an electron or a high-energy photon beam that is synchronized to an infrared laser pulse. Entirely new opportunities can be explored if not only a single, but multiple synchronized, ultrashort, high-energy beams are used. However, this requires advanced radiation sources that are capable of producing dual-energy electron beams, for example. Here, we demonstrate simultaneous generation of twin-electron beams from a single compact laser wakefield accelerator. The energy of each beam can be individually adjusted over a wide range and our analysis shows that the bunch lengths and their delay inherently amount to femtoseconds. Our proof-of-concept results demonstrate an elegant way to perform multi-beam experiments in the future on a laboratory scale.

The occurrence of isomers of the bicyclic octapeptide α-amanitin, which presents a macrolactam with a tryptathionine cross-link forming a handle, has been reported under the term of atropoisomers. Here, the authors synthesize its analogs and analyse their isomers, proposing and describing for them the term ansamer.

Abstract Background The coronavirus pandemic led to a lockdown of public life. For universities, this meant suspensions or corresponding adaptations of practical courses. In Germany, Kiel Dental Clinic received special permission to start practical courses under appropriate hygiene conditions. The study aimed at recording the experiences and associated challenges of course implementation under the special regulations from the perspective of students and teachers. Methods Qualitative guided interviews were conducted with students and teachers at Kiel in the summer semester 2020. Students (4th, 6th, 8th, 10th semesters) were recruited and lecturers responsible for conducting the practical courses within the dental clinic’s four departments. Evaluation was carried out by means of qualitative content analysis, whereby deductive procedures were supplemented by inductive ones. Results Thirty-nine students and 19 lecturers took part. The flow of information at the start of the course was welcomed by students and teachers across the board. The lack of or limited adjustment to the scope tended to be assessed positively by students. The majority of both groups suspected there had been no reduction in learning, and learning had been improved due to the smaller group sizes. Regarding the necessary conditions for conducting the course, positive and negative aspects became apparent. Conclusion Students and teachers felt very relief to start the practical courses under special conditions although the implementation was very challenging for both groups. The structural and content-related course adaptations required a high degree of flexibility on the part of students and lecturers alike, but also meant that courses were able to be conducted without serious deficits in learning gains.

Malaria-causing parasites achieve rapid proliferation in human blood through multiple rounds of asynchronous nuclear division followed by daughter cell formation. Nuclear divisions critically depend on the centriolar plaque, which organizes intranuclear spindle microtubules. The centriolar plaque consists of an extranuclear compartment, which is connected via a nuclear pore-like structure to a chromatin-free intranuclear compartment. Composition and function of this non-canonical centrosome remain largely elusive. Centrins, which reside in the extranuclear part, are among the very few centrosomal proteins conserved in Plasmodium falciparum. Here we identify a novel centrin-interacting centriolar plaque protein. Conditional knock down of this Sfi1-like protein (PfSlp) caused a growth delay in blood stages, which correlated with a reduced number of daughter cells. Surprisingly, intranuclear tubulin abundance was significantly increased, which raises the hypothesis that the centriolar plaque might be implicated in regulating tubulin levels. Disruption of tubulin homeostasis caused excess microtubules and aberrant mitotic spindles. Time-lapse microscopy revealed that this prevented or delayed mitotic spindle extension but did not significantly interfere with DNA replication. Our study thereby identifies a novel extranuclear centriolar plaque factor and establishes a functional link to the intranuclear compartment of this divergent eukaryotic centrosome.

Abstract Background One relevant strategy to prevent the onset and progression of type 2 diabetes mellitus (T2DM) focuses on increasing physical activity. The use of activity trackers by patients could enable objective measurement of their regular physical activity in daily life and promote physical activity through the use of a tracker-based intervention. This trial aims to answer three research questions: (1) Is the use of activity trackers suitable for longitudinal assessment of physical activity in everyday life? (2) Does the use of a tracker-based intervention lead to sustainable improvements in the physical activity of healthy individuals and in people with T2DM? (3) Does the accompanying digital motivational intervention lead to sustainable improvements in physical activity for participants using the tracker-based device? Methods The planned study is a randomized controlled trial focused on 1642 participants with and without T2DM for 9 months with regard to their physical activity behavior. Subjects allocated to an intervention group will wear an activity tracker. Half of the subjects in the intervention group will also receive an additional digital motivational intervention. Subjects allocated to the control group will not receive any intervention. The primary outcome is the amount of moderate and vigorous physical activity in minutes and the number of steps per week measured continuously with the activity tracker and assessed by questionnaires at four time points. Secondary endpoints are medical parameters measured at the same four time points. The collected data will be analyzed using inferential statistics and explorative data-mining techniques. Discussion The trial uses an interdisciplinary approach with a team including sports psychologists, sports scientists, health scientists, health care professionals, physicians, and computer scientists. It also involves the processing and analysis of large amounts of data collected with activity trackers. These factors represent particular strengths as well as challenges in the study. Trial Registration The trial is registered at the World Health Organization International Clinical Trials Registry Platform via the German Clinical Studies Trial Register (DRKS), DRKS00027064 . Registered on 11 November 2021.

The surface pressure fluctuations, which are a source of low-frequency noise emissions, are numerically investigated on a 2 MW wind turbine under different inflow conditions. In order to evaluate the impact of a complex-terrain flow, a computational setup is presented that is aimed at reproducing a realistic flow field in the complex terrain in Perdigão, Portugal. A precursor simulation with the steady-state atmospheric computational fluid dynamics (CFD) code E-Wind is used, which was calibrated with meteorological (met) mast data to generate a site- and situation-specific inflow for a high-resolution delayed detached-eddy simulation (DDES) with FLOWer. A validation with lidar and met mast data reveals a good agreement of the flow field in the vicinity of the turbine in terms of mean wind speed and wind direction, whereas the turbulence intensity is slightly underestimated. Further downstream in the valley and on the second ridge, the deviations between simulation and measurement become significantly larger. The geometrically resolved turbine is coupled to the structural solver SIMPACK and simulated both in the complex terrain and in flat terrain with simpler inflows as reference. The surface pressure fluctuations are evaluated on the tower and blades. It is found that the periodic pressure fluctuations at the tower sides and back are dominated by vortex shedding, which strongly depends on the inflow and is reduced by inflow turbulence. However, the dominant pressure fluctuations on the upper part of the tower, which are caused by the blade–tower interaction, remain almost unchanged by the different inflows. The predominant pressure fluctuations on the blades occur with the rotation frequency. They are caused by a combination of rotor tilt, vertical wind shear and inclined flow and are thus strongly dependent on the inflow and the surrounding terrain. The inflow turbulence masks fluctuations at higher harmonics of the blade–tower interaction with its broadband characteristic caused by the interaction of the leading edge and the inflow turbulence.

Scientific tasks aimed at decoding and characterizing complex systems and processes at high pressures set new challenges for modern X-ray diffraction instrumentation in terms of X-ray flux, focal spot size and sample positioning. Presented here are new developments at the Extreme Conditions beamline (P02.2, PETRA III, DESY, Germany) that enable considerable improvements in data collection at very high pressures and small scattering volumes. In particular, the focusing of the X-ray beam to the sub-micrometer level is described, and control of the aberrations of the focusing compound refractive lenses is made possible with the implementation of a correcting phase plate. This device provides a significant enhancement of the signal-to-noise ratio by conditioning the beam shape profile at the focal spot. A new sample alignment system with a small sphere of confusion enables single-crystal data collection from grains of micrometer to sub-micrometer dimensions subjected to pressures as high as 200 GPa. The combination of the technical development of the optical path and the sample alignment system contributes to research and gives benefits on various levels, including rapid and accurate diffraction mapping of samples with sub-micrometer resolution at multimegabar pressures.