De Haas-van Alphen spectroscopy and magnetic breakdown in moiré graphene.

Quantum oscillations originating from the quantization of electron cyclotron orbits provide sensitive diagnostics of electron bands and interactions. We report on nanoscale imaging of the thermodynamic magnetization oscillations caused by the de Haas-van Alphen effect in moiré graphene. Scanning by means of superconducting quantum interference device (SQUID)-on-tip in Bernal bilayer graphene crystal axis-aligned to hexagonal boron nitride reveals large magnetization oscillations with amplitudes reaching 500 Bohr magneton per electron in weak magnetic fields, unexpectedly low frequencies, and high sensitivity to superlattice filling fraction. The oscillations allow us to reconstruct the complex band structure, revealing narrow moiré bands with multiple overlapping Fermi surfaces separated by unusually small momentum gaps. We identified sets of oscillations that violate the textbook Onsager Fermi surface sum rule, signaling formation of broad-band particle-hole superposition states induced by coherent magnetic breakdown.

Imaging quantum oscillations and millitesla pseudomagnetic fields in graphene.

The exceptional control of the electronic energy bands in atomically thin quantum materials has led to the discovery of several emergent phenomena1. However, at present there is no versatile method for mapping the local band structure in advanced two-dimensional materials devices in which the active layer is commonly embedded in the insulating layers and metallic gates. Using a scanning superconducting quantum interference device, here we image the de Haas-van Alphen quantum oscillations in a model system, the Bernal-stacked trilayer graphene with dual gates, which shows several highly tunable bands2-4. By resolving thermodynamic quantum oscillations spanning more than 100 Landau levels in low magnetic fields, we reconstruct the band structure and its evolution with the displacement field with excellent precision and nanoscale spatial resolution. Moreover, by developing Landau-level interferometry, we show shear-strain-induced pseudomagnetic fields and map their spatial dependence. In contrast to artificially induced large strain, which leads to pseudomagnetic fields of hundreds of tesla5-7, we detect naturally occurring pseudomagnetic fields as low as 1 mT corresponding to graphene twisting by 1 millidegree, two orders of magnitude lower than the typical angle disorder in twisted bilayer graphene8-11. This ability to resolve the local band structure and strain at the nanoscale level enables the characterization and use of tunable band engineering in practical van der Waals devices.

Magnetic Imaging and Domain Nucleation in CrSBr Down to the 2D Limit.

Recent advancements in 2D materials have revealed the potential of van der Waals magnets, and specifically of their magnetic anisotropy that allows applications down to the 2D limit. Among these materials, CrSBr has emerged as a promising candidate, because its intriguing magnetic and electronic properties have appeal for both fundamental and applied research in spintronics or magnonics. In this work, nano-SQUID-on-tip (SOT) microscopy is used to obtain direct magnetic imaging of CrSBr flakes with thicknesses ranging from monolayer (N = 1) to few-layer (N = 5). The ferromagnetic order is preserved down to the monolayer, while the antiferromagnetic coupling of the layers starts from the bilayer case. For odd layers, at zero applied magnetic field, the stray field resulting from the uncompensated layer is directly imaged. The progressive spin reorientation along the out-of-plane direction (hard axis) is also measured with a finite applied magnetic field, allowing evaluation of the anisotropy constant, which remains stable down to the monolayer and is close to the bulk value. Finally, by selecting the applied magnetic field protocol, the formation of Néel magnetic domain walls is observed down to the single-layer limit.

DICOM® integrated EEG data: A first clinical implementation of the new DICOM standard for neurophysiology data.

OBJECTIVE: Demonstrating a pilot implementation of the Digital Imaging and Communication in Medicine (DICOM) neurophysiology standard published in 2020. METHODS: An automated workflow for converting EEG data from a proprietary vendor EEG format to standardized and interoperable DICOM format was developed and tested. RESULTS: Retrieval of proprietary EEG data, associated videos, annotations and metadata from the vendor EEG archive and their subsequent conversion to DICOM EEG was possible without changes to the departmental workflow. To transfer DICOM EEG data to the central radiology DICOM archive, only minor extensions in the parameterization of the archive's DICOM interfaces were necessary. Linkage with the electronic health record (EHR) and display in a DICOM EEG viewer could be demonstrated. A random sample of 88 DICOM EEG studies was compared to the original vendor files and EEG and video file sizes were comparable. CONCLUSIONS: Storing and reviewing EEG data in standardized DICOM format is feasible, facilitated by existing DICOM infrastructure, and therefore allows for vendor independent access to EEG data. SIGNIFICANCE: We report the first implementation of the DICOM neurophysiology standard, thus promoting standardization in the field of neurophysiology as well as data exchange and access to legacy recordings in an interoperable vendor independent format.

Hip and trunk kinematics during reaching on a mobile and stable seat.

Reaching movements are often used to assess selective trunk control in people with neurological conditions. Also, it is known that reaching performance after stroke is increased through training on a mobile seat compared to conventional physical therapy. However, the effect of a mobile seat on joint kinematics has not yet been investigated. This study aimed to quantify differences in the range of motion of the hip and trunk during reaching exercises on a mobile and stable sitting surface. Fifteen healthy participants performed reaching beyond arm's length on a mobile and a stable seat in four different directions: ipsilateral, anterior, contralateral, and contralateral diagonal. Biomechanical data were collected, including kinematics of the hip and trunk, and surface electromyography of the trunk muscles. The mobile sitting surface led to a higher range of motion in the trunk and the hip in the frontal and sagittal plane, but not in the rotational plane. Differences between reaching directions were found in all joint directions, except that of trunk flexion. Hence, movement patterns of the hip and trunk differ during reaching on different sitting surfaces and in different directions. A larger range of motion in the frontal or sagittal plane while training on the mobile seat provides added neuromuscular stimuli to the trunk muscles (= a higher demand on trunk muscles), which could result in more efficient training and therefore, increased trunk control after stroke. However, this has to be investigated in a future study with people after stroke.

Long-Term Total Neoadjuvant Therapy Leads to Impressive Response Rates in Rectal Cancer: Results of a German Single-Center Cohort.

Intensified preoperative chemotherapy after (chemo)radiotherapy, (Total Neoadjuvant Therapy-TNT), increases pathological complete response (pCR) rates and local control. In cases of clinically complete response (cCR) and close follow-up, non-operative management (NOM) is feasible. We report early outcomes and toxicities of a long-term TNT regime in a single-center cohort. Fifteen consecutive patients with distal or middle-third locally advanced rectal cancer (UICC stage II-III) were investigated, who received neoadjuvant chemoradiotherapy (total adsorbed dose: 50.4 Gy in 28 fractions and two concomitant courses 5-fluorouracil (250 mg/m2/d)/oxaliplatin (50 mg/m2), followed by consolidating chemotherapy (nine courses of FOLFOX4). NOM was offered if staging revealed cCR 2 months after TNT, with resection performed otherwise. The primary endpoint was complete response (pCR + cCR). Treatment-related side effects were quantified for up two years after TNT. Ten patients achieved cCR, of whom five opted for NOM. Ten patients (five cCR and five non-cCR) underwent surgery, with pCR confirmed in the five patients with cCR. The main toxicities comprised leukocytopenia (13/15), fatigue (12/15) and polyneuropathy (11/15). The most relevant CTC °III + IV events were leukocytopenia (4/15), neutropenia (2/15) and diarrhea (1/15). The long-term TNT regime resulted in promising response rates that are higher than the response rates of short TNT regimes. Overall tolerability and toxicity were comparable with the results of prospective trials.

Scanning SQUID-on-tip microscope in a top-loading cryogen-free dilution refrigerator.

The scanning superconducting quantum interference device (SQUID) fabricated on the tip of a sharp quartz pipette (SQUID-on-tip) has emerged as a versatile tool for the nanoscale imaging of magnetic, thermal, and transport properties of microscopic devices of quantum materials. We present the design and performance of a scanning SQUID-on-tip microscope in a top-loading probe of a cryogen-free dilution refrigerator. The microscope is enclosed in a custom-made vacuum-tight cell mounted at the bottom of the probe and is suspended by springs to suppress vibrations caused by the pulse tube cryocooler. Two capillaries allow for the in situ control of helium exchange gas pressure in the cell that is required for thermal imaging. A nanoscale heater is used to create local temperature gradients in the sample, which enables quantitative characterization of relative vibrations between the tip and the sample. The spectrum of the vibrations shows distinct resonant peaks with a maximal power density of about 27 nm/Hz1/2 in the in-plane direction. The performance of the SQUID-on-tip microscope is demonstrated by magnetic imaging of the MnBi2Te4 magnetic topological insulator, magnetization and current distribution imaging in a SrRuO3 ferromagnetic oxide thin film, and thermal imaging of dissipation in graphene.

Nano-Patterned Magnetic Edges in CrGeTe3 for Quasi 1-D Spintronic Devices.

The synthesis of two-dimensional van der Waals magnets has paved the way for both technological applications and fundamental research on magnetism confined to ultra-small length scales. Edge magnetic moments in ferromagnets are expected to be less magnetized than in the sample interior because of the reduced amount of neighboring ferromagnetic spins at the sample edge. We recently demonstrated that CrGeTe3 (CGT) flakes thinner than 10 nm are hard ferromagnets; i.e., they exhibit an open hysteresis loop. In contrast, thicker flakes exhibit zero net remnant field in the interior, with hard ferromagnetism present only at the cleaved edges. This experimental observation suggests that a nontrivial interaction exists between the sample edge and the interior. Here, we demonstrate that artificial edges fabricated by focus ion beam etching also display hard ferromagnetism. This enables us to write magnetic nanowires in CGT directly and use this method to characterize the magnetic interaction between the interior and edge. The results indicate that the interior saturation and depolarization fields depend on the lateral dimensions of the sample. Most notably, the interior region between the edges of a sample narrower than 300 nm becomes a hard ferromagnet, suggesting an enhancement of the magnetic exchange induced by the proximity of the edges. Last, we find that the CGT regions amorphized by the gallium beam are nonmagnetic, which introduces a novel method to tune the local magnetic properties of CGT films, potentially enabling integration into spintronic devices.

How causal machine learning can leverage marketing strategies: Assessing and improving the performance of a coupon campaign.

We apply causal machine learning algorithms to assess the causal effect of a marketing intervention, namely a coupon campaign, on the sales of a retailer. Besides assessing the average impacts of different types of coupons, we also investigate the heterogeneity of causal effects across different subgroups of customers, e.g., between clients with relatively high vs. low prior purchases. Finally, we use optimal policy learning to determine (in a data-driven way) which customer groups should be targeted by the coupon campaign in order to maximize the marketing intervention's effectiveness in terms of sales. We find that only two out of the five coupon categories examined, namely coupons applicable to the product categories of drugstore items and other food, have a statistically significant positive effect on retailer sales. The assessment of group average treatment effects reveals substantial differences in the impact of coupon provision across customer groups, particularly across customer groups as defined by prior purchases at the store, with drugstore coupons being particularly effective among customers with high prior purchases and other food coupons among customers with low prior purchases. Our study provides a use case for the application of causal machine learning in business analytics to evaluate the causal impact of specific firm policies (like marketing campaigns) for decision support.

The Effect on Muscle Activity of Reaching Beyond Arm's Length on a Mobile Seat: A Pilot Study for Trunk Control Training for People After Stroke.

Objective: This pilot study compared muscle activity during lateral reaching tasks between mobile and stable sitting using a novel therapy chair in people after stroke and healthy controls. Design: Observational pilot study. Setting: This study was conducted in a rehabilitation center for people after stroke and at the university's movement laboratory for healthy participants. Participants: A total of eleven people after stroke and fifteen healthy people (N=26) took part. Interventions: Lateral reaching exercises to the ipsilateral and contralateral sides were performed on a mobile and a stable seat. Main Outcome Measure: Muscular activity of the multifidus, erector spinae and external oblique was measured bilaterally. A within-subject linear mixed model was applied to analyze the effects of seat condition, task, muscle side, and group. Results: A seat condition effect was found for the multifidus and external oblique that was dependent on the muscle side and task. During ipsilateral reaching, the activity of the multifidi decreased for people after stroke on the mobile seat, while increasing for healthy participants. The erector spinae showed no condition effect. Decreased activity of the external oblique was found for both groups on the mobile seat. Conclusions: Mobile sitting influences muscular activity. However, these preliminary results should be further investigated in order to generate recommendations for rehabilitation.

Rapid and robust endoscopic content area estimation: A lean GPU-based pipeline and curated benchmark dataset.

Endoscopic content area refers to the informative area enclosed by the dark, non-informative, border regions present in most endoscopic footage. The estimation of the content area is a common task in endoscopic image processing and computer vision pipelines. Despite the apparent simplicity of the problem, several factors make reliable real-time estimation surprisingly challenging. The lack of rigorous investigation into the topic combined with the lack of a common benchmark dataset for this task has been a long-lasting issue in the field. In this paper, we propose two variants of a lean GPU-based computational pipeline combining edge detection and circle fitting. The two variants differ by relying on handcrafted features, and learned features respectively to extract content area edge point candidates. We also present a first-of-its-kind dataset of manually annotated and pseudo-labelled content areas across a range of surgical indications. To encourage further developments, the curated dataset, and an implementation of both algorithms, has been made public (https://doi.org/10.7303/syn32148000, https://github.com/charliebudd/torch-content-area). We compare our proposed algorithm with a state-of-the-art U-Net-based approach and demonstrate significant improvement in terms of both accuracy (Hausdorff distance: 6.3 px versus 118.1 px) and computational time (Average runtime per frame: 0.13 ms versus 11.2 ms).

Multi-level network dataset of ten Swiss wetlands governance cases based on qualitative interviews and quantitative surveys.

The dataset of this paper originated from quantitative online surveys and qualitative expert interviews with organizational actors relevant to the governance of ten Swiss wetlands from 2019 till 2021. Multi-level networks represent the wetlands governance for each of the ten cases. The collaboration networks of actors form the first level of the multi-level networks and are connected to multiple other network levels that account for the social and ecological systems those actors are active in. 521 actors relevant to the management of the ten wetlands are included in the collaboration networks; quantitative survey data exists for 71% of them. A unique feature of the collaboration networks is that it differentiates between positive and negative forms of collaboration specified based on actors' activity areas. Therefore, the data describes not only if actors collaborate but also how and where actors collaborate. Further additional two-mode networks (actor participation in forums and involvement in other regions outside the case area) are elicited in the survey and connected to the collaboration network. Finally, the dataset also contains data on ecological system interdependencies in the form of conceptual maps derived from 34 expert interviews (3-4 experts per case).

Surface electromyographic activity of trunk muscles during trunk control exercises for people after stroke; effect of a mobile and stable seat for rehabilitation.

The aim of this study was to explore differences in trunk muscle activity on a stable and mobile seat for people after stroke and healthy participants. Trunk control exercises are known to have a beneficial effect on trunk control, balance, and mobility after stroke. The effect of such exercises could be enhanced by the use of a mobile seat to provide further training stimuli. However, little research on the musculoskeletal effects of trunk training on mobile seats has been carried out. On a stable and a mobile seat, thirteen people after stroke and fifteen healthy participants performed two selective trunk control exercises, which were lateral flexion initiated by the pelvis and the thorax. The maximal surface electromyography relative to static sitting of the muscles multifidus, erector spinae, and obliquus externus was recorded bilaterally. The effects of group, seat condition, trunk control exercise, and muscle side were investigated employing within-subject linear-mixed-models. Compared to the stable seat, the maximal muscle activity of people after stroke on the mobile seat was higher during the thorax-initiated exercise and lower during the pelvis-initiated exercise. Healthy participants showed opposite results with higher muscle activity on the mobile seat during the pelvis-initiated exercise. For trunk control training on a mobile seat with high muscle activation people after stroke should perform trunk control exercises initiated by the thorax, for training with lower muscle activity people after stroke should initiate selective trunk movements by the pelvis. The results can support the planning of progressive trunk control rehabilitation programs.

[Instruments of official communication by regulatory authorities on risks of drug use]. / Instrumente behördlicher Kommunikation zu Anwendungsrisiken von Arzneimitteln.

Active communication of authorities, such as the Federal Institute for Drugs and Medical Devices (BfArM) and the Paul Ehrlich Institute (PEI), including maintenance of contacts with health care professionals, as well as press and public relations work, are essential prerequisites for ensuring that information on the risks of using medicinal products reaches both affected patients and healthcare professionals quickly and in a targeted manner. The various instruments of targeted communication describe possible risks and also contain recommendations that help to reduce the risk of using a medicinal product. The supplementary public relations work aims to make the tasks and objectives of the authority known to the public and to experts with the goal of creating and expanding trust in the actions of the authorities. To this end, appropriate communication platforms must be established and accepted so that they are used by both experts and the general public and the authority is perceived and appreciated as a reliable source of risk information. The currently available instruments of targeted risk communication, such as Dear Health Care Professional Communication (DHPC), risk management plans, and educational materials are described in this paper as well as broader communication on official websites or towards the media. Finally, PEI's risk communication is highlighted with particular reference to COVID-19 vaccines.

Interior and Edge Magnetization in Thin Exfoliated CrGeTe3 Films.

CrGeTe3 (CGT) is a semiconducting vdW ferromagnet shown to possess magnetism down to a two-layer thick sample. Although CGT is one of the leading candidates for spintronics devices, a comprehensive analysis of CGT thickness dependent magnetization is currently lacking. In this work, we employ scanning SQUID-on-tip (SOT) microscopy to resolve the magnetic properties of exfoliated CGT flakes at 4.2 K. Combining transport measurements of CGT/NbSe2 samples with SOT images, we present the magnetic texture and hysteretic magnetism of CGT, thereby matching the global behavior of CGT to the domain structure extracted from local SOT magnetic imaging. Using this method, we provide a thickness dependent magnetization state diagram of bare CGT films. No zero-field magnetic memory was found for films thicker than 10 nm, and hard ferromagnetism was found below that critical thickness. Using scanning SOT microscopy, we identify a unique edge magnetism, contrasting the results attained in the CGT interior.

Deep homography estimation in dynamic surgical scenes for laparoscopic camera motion extraction.

Current laparoscopic camera motion automation relies on rule-based approaches or only focuses on surgical tools. Imitation Learning (IL) methods could alleviate these shortcomings, but have so far been applied to oversimplified setups. Instead of extracting actions from oversimplified setups, in this work we introduce a method that allows to extract a laparoscope holder's actions from videos of laparoscopic interventions. We synthetically add camera motion to a newly acquired dataset of camera motion free da Vinci surgery image sequences through a novel homography generation algorithm. The synthetic camera motion serves as a supervisory signal for camera motion estimation that is invariant to object and tool motion. We perform an extensive evaluation of state-of-the-art (SOTA) Deep Neural Networks (DNNs) across multiple compute regimes, finding our method transfers from our camera motion free da Vinci surgery dataset to videos of laparoscopic interventions, outperforming classical homography estimation approaches in both, precision by 41%, and runtime on a CPU by 43%.

Gender differences in wage expectations.

Using an own survey on wage expectations among students at two Swiss institutions of higher education, we examine the wage expectations of our respondents along two main lines. First, we investigate the rationality of wage expectations by comparing average expected wages from our sample with those of similar graduates; further, we examine how our respondents revise their expectations when provided information about actual wages. Second, using causal mediation analysis, we test whether the consideration of a rich set of personal and professional controls, inclusive of preferences on family formation and number of children in addition to professional preferences, accounts for the difference in wage expectations across genders. Results suggest that both males and females overestimate their wages compared to actual ones and that males respond in an overconfident manner to information about realized wages. Personal mediators alone cannot explain the indirect effect of gender on wage expectations; however, when combined with professional mediators, this results in a quantitatively large reduction in the unexplained effect of gender on wage expectations. Nonetheless, a non-negligible and statistically significant direct (or unexplained) effect of gender on wage expectations remains in several, but not all specifications.

Timing matters: the impact of response measures on COVID-19-related hospitalization and death rates in Germany and Switzerland.

We assess the impact of the timing of lockdown measures implemented in Germany and Switzerland on cumulative COVID-19-related hospitalization and death rates. Our analysis exploits the fact that the epidemic was more advanced in some regions than in others when certain lockdown measures came into force, based on measuring health outcomes relative to the region-specific start of the epidemic and comparing outcomes across regions with earlier and later start dates. When estimating the effect of the relative timing of measures, we control for regional characteristics and initial epidemic trends by linear regression (Germany and Switzerland), doubly robust estimation (Germany), or synthetic controls (Switzerland). We find for both countries that a relatively later exposure to the measures entails higher cumulative hospitalization and death rates on region-specific days after the outbreak of the epidemic, suggesting that an earlier imposition of measures is more effective than a later one. For Germany, we further evaluate curfews (as introduced in a subset of states) based on cross-regional variation. We do not find any effects of curfews on top of the federally imposed contact restriction that banned groups of more than 2 individuals.

[Psychiatric polypharmacy and electroconvulsive therapy in treatment-resistant depression]. / Psychiatrische Polypharmazie und Elektrokonvulsionstherapie bei therapieresistenter Depression.

BACKGROUND: Despite its relevant medical risks, polypharmacy is common particularly among difficult to treat conditions, e.g. treatment refractory depression (TRD). According to numerous guidelines, electroconvulsive therapy (ECT) is the treatment of choice in severe and treatment-resistant major depression due to the high effectiveness; however, to date limited data are available concerning the effects of ECT on the concomitant prescription of psychiatric medication. METHODS: For a retrospective explorative analysis of psychiatric polypharmacy (MED) in TRD, data from 58 inpatient treatments were collected. Due to depressive episodes, all patients received psychopharmacological treatment and cognitive behavioral therapy (MED group). Of the patients 29 also underwent ECT (ECT group). Using a modified drug burden index (mod-DBI), the psychiatric medication was quantified at admission (TP0), start (TP1) and termination of ECT (TP2) and discharge in the ECT group or in comparable periods in the MED group (TP3). Differences in distribution were tested with the t-test and alterations in measurements were tested by means of variance analysis (F-test). RESULTS: Patients treated with ECT showed higher mod-DBI values at TP0, mainly due to more frequent prescription of benzodiazepines (BZD), mood stabilizers (MS) and antipsychotic drugs (AP). At the beginning of the inpatient treatment (TP0-TP1) there was an increase in BZD use (in both groups); in the ECT group MS were reduced and AP increased. In the time interval TP1-TP3, BZD (in both groups) and AP (ECT group) were again less frequently prescribed and MS (ECT and MED group) were increased again. Excluding BZD, there was a significant increase in mod-DBI in both groups, whereas the mod-DBI no longer showed significant differences at TP2 and TP3. CONCLUSION: The data possibly indicate that patients with TRD who receive ECT during inpatient treatment already have a more extensive psychiatric medication at admission. Also, psychiatric medication appears to be increased less prominently when ECT is performed. These findings and the possibly associated long-term benefits should be addressed in future research.

Scanning SQUID microscopy in a cryogen-free cooler.

Scanning superconducting quantum interference device (SQUID) microscopy is a powerful tool for investigating electronic states at surfaces and interfaces by mapping their magnetic signal. SQUID operation requires cryogenic temperatures, which are typically achieved by immersing the cryostat in liquid helium. Making a transition to cryogen free systems is desirable, but has been challenging, as electric noise and vibrations are increased in such systems. We report on the successful operation of a scanning SQUID microscope in a modified Montana Instruments cryogen-free cooler with a base temperature of 4.3 K. We demonstrate scanning SQUID measurements with flux noise performance comparable to a wet system and correlate the sensor-sample vibrations to the cryocooler operation frequencies. In addition, we demonstrate successful operation in a variety of SQUID operation modes, including mapping static magnetic fields, measurement of local susceptibility, and spatial mapping of current flow distribution.