Measuring Situational Cognitive Performance in the Wild: A Psychometric Evaluation of Three Brief Smartphone-Based Test Procedures.

Mobile devices provide new opportunities to draw conclusions about cognitive performance in everyday situations. To gain insights into cognitive performance patterns in healthy adult populations, we adapted three established cognitive tests for smartphone use: the Digit Symbol Substitution Task (DSST), Sustained Attention to Response Task (SART), and Psychomotor Vigilance Task (PVT). To increase their feasibility for ambulatory assessment, we identified the minimum measurement durations that provide reliable and valid state measures of cognitive performance. Over 2 weeks, 46 participants performed each test once per day at random times, along with self-reports (e.g., on concentration, mood, and mental demands). The validity and reliability of change are promising for the 30-second PVT and 90-second DSST and SART. The DSST and SART provide fruitful outcomes for ambulatory field studies linked to mood, stress, and mental demands. We provide digital versions of the adapted DSST and SART online for free.

Live-streaming Activity and Relaxation Breaks: a (Home-)Office-Compatible Approach to Promote Break Recovery, Mood, and Attention?

The aim of this study is to investigate whether short, live-streaming activity and relaxation lunch breaks have positive associations with office workers' mood (calmness, valence, and energetic arousal), back pain, and attention after break and whether these associations are mediated by better break recovery. Additionally, we considered the two respite interventions as resources possibly buffering the effects of elevated situational job demands. Ten-minute break exercises were conducted during lunch breaks via Zoom live-stream, and data on those days were compared with data on days on which participants spent their breaks as usual. Our sample of 34 office workers provided data for 277 work days (209 in the home office and 68 on site at the company). Multilevel path models revealed positive total associations of both respite interventions with the mood dimension of calmness. Activity breaks additionally showed a positive association with the energetic arousal dimension of mood, while relaxation breaks were positively related to objectively measured cognitive performance. Interestingly, activity breaks moderated the relationships of job demands with calmness and valence, indicating their function as a stress-buffering resource. There were no significant associations between the two respite interventions and back pain. Supplemented by participants' feedback, the findings of this study suggest that offering short virtually guided break exercises may represent a feasible and office-compatible approach to promote break recovery, mood and functionality at work, especially regarding home-office work. Possible advantages and disadvantages of the live-streaming format are discussed.

Weakly supervised end-to-end artificial intelligence in gastrointestinal endoscopy.

Artificial intelligence (AI) is widely used to analyze gastrointestinal (GI) endoscopy image data. AI has led to several clinically approved algorithms for polyp detection, but application of AI beyond this specific task is limited by the high cost of manual annotations. Here, we show that a weakly supervised AI can be trained on data from a clinical routine database to learn visual patterns of GI diseases without any manual labeling or annotation. We trained a deep neural network on a dataset of N = 29,506 gastroscopy and N = 18,942 colonoscopy examinations from a large endoscopy unit serving patients in Germany, the Netherlands and Belgium, using only routine diagnosis data for the 42 most common diseases. Despite a high data heterogeneity, the AI system reached a high performance for diagnosis of multiple diseases, including inflammatory, degenerative, infectious and neoplastic diseases. Specifically, a cross-validated area under the receiver operating curve (AUROC) of above 0.70 was reached for 13 diseases, and an AUROC of above 0.80 was reached for two diseases in the primary data set. In an external validation set including six disease categories, the AI system was able to significantly predict the presence of diverticulosis, candidiasis, colon and rectal cancer with AUROCs above 0.76. Reverse engineering the predictions demonstrated that plausible patterns were learned on the level of images and within images and potential confounders were identified. In summary, our study demonstrates the potential of weakly supervised AI to generate high-performing classifiers and identify clinically relevant visual patterns based on non-annotated routine image data in GI endoscopy and potentially other clinical imaging modalities.

Radon protection in apartments using a ventilation system wireless-controlled by radon activity concentration.

The new German Radiation Protection Act (StrlSchG) of 31 December 2018 established a reference value of 300 Bq m-3for the annual average radon activity concentration in buildings with recreation and living rooms, as well as in workplaces. It is expected that the reference value will be exceeded in a vast number of buildings throughout Germany and that radon protection measures will become indispensable. A simple and inexpensive radon protection measure for existing buildings is ventilation. In the scope of a joint project, ventilation systems with zone control and heat recovery are to be extended by the control parameter radon activity concentration. A highly sensitive, miniaturized radon monitor will be developed for this purpose, which can be integrated wirelessly into ventilation systems. Radon measurements were carried out in 13 apartments of an unoccupied heated apartment block in Germany over a period of three weeks in the wintertime. High radon activity concentrations were found on all three floors. The maximum values were 14000 Bq m-3on the first floor, 6000 Bq m-3on the second floor, and 2000 Bq m-3on the third floor. Ventilation experiments were carried out in an apartment with high radon activity concentration. Two decentralized ventilation systems with heat recovery were installed in each of the two opposite outside walls. The controlling device of the system was activated wirelessly depending on the radon activity concentration. The radon activity concentration was reduced from 8000 Bq m-3to 800 Bq m-3in a first experiment in the living room.

The interactive effects of heart rate variability and mindfulness on indicators of well-being in healthcare professionals' daily working life.

OBJECTIVE: Heart rate variability (HRV) and mindfulness have been described as correlates of self-regulation and well-being. The goal of the present study was to investigate their interactions from a within-person perspective in the context of work. METHODS: Applying an ambulatory assessment approach, we studied 89 healthcare professionals across two to four work shifts. Self-reports of momentary job demands, mindfulness, and well-being (as indicated by emotional exhaustion, relaxation, and contentment) were provided three to four times a day via smartphone questionnaires. Electrocardiogram and activity sensors continuously recorded data from the beginning to the end of the shifts. Multilevel models based on 937 measurements were built for emotional exhaustion, relaxation, and contentment. RESULTS: After controlling for covariates, including bodily movement, shift, and job demands, short-term HRV was marginally significantly related to decreased emotional exhaustion and significantly related to increased relaxation. State mindfulness was significantly related to decreased emotional exhaustion, and increased relaxation and contentment. Furthermore, HRV and mindfulness significantly interacted such that emotional exhaustion was lowest and relaxation was highest when both HRV and mindfulness were high. CONCLUSIONS: Together, the findings provide insights into the use of HRV and mindfulness as indexes of psychophysiological regulatory resources that seemingly intensify their respective beneficial effects on the daily well-being of employees.

Teachers' ambulatory heart rate variability as an outcome and moderating variable in the job demands-resources model.

Background and Objectives: According to the job demands-resources (JD-R) model, strain reactions are based on the level of job demands and moderating resources. The present study aims to contribute to psychophysiological research by integrating vagally mediated heart rate variability (HRV) into the JD-R framework. Design and Methods: Using a sample of school teachers, we conducted an ambulatory assessment study to investigate HRV as (1) a state outcome measure of job demands and resources and (2) a trait moderator in the relationship between job demands and emotional exhaustion. In total, 101 participants wore an electrocardiogram device on two school days and rated their level of job demands (emotional demands and time pressure), job resources (control and support), and exhaustion six times a day. Based on 669 measurements, multilevel models of the 5-minute state HRV measure and emotional exhaustion were built. Results: The results supported the health-impairing effects of job demands on emotional exhaustion but not state HRV. There was no evidence of the moderating effects of job resources. Notably, the 48-hour trait HRV measure significantly buffered the effect of emotional demands on exhaustion. Conclusions: These findings highlight the stress-buffering potential of trait HRV as theoretical research extension and practical intervention goal.

Characterization of the vasa vasorum in the human great saphenous vein: a scanning electron microscopy and 3D-morphometry study using vascular corrosion casts.

The vasa vasorum (VV) of explanted segments of the human great saphenous vein (Vena saphena magna; HGSV), harvested during dissection for coronary bypass grafts or diseased vein segments from the "Salzburger Landesklinikum," were studied by scanning electron microscopy and three-dimensional morphometry of microvascular corrosion casts. The main objective of this study was to examine the VV's structural arrangement in order to find the most vital segments of the HGSV and in turn to improve the results of coronary bypass surgeries. The study presents a meticulous analysis of the whole microvascular system of the VV of the HGSV and its three-dimensional arrangement. It is one of the first studies yielding detailed quantitative data on geometry of the VV of the HGSV. A detailed insight into different vascular parameters such as vessel diameter, interbranching, intervascular distances, and branching angles at different levels of the VV's angioarchitecture and in different parts of the HGSV in health and disease is given. Further, the geometry of bifurcations was examined in order to compute the physiological optimality principles of this delicate vascular system based on its construction, maintenance, and function.

Determination of the overall migration from silicone baking moulds into simulants and food using 1H-NMR techniques.

Different silicone baking moulds (37 samples) were characterized with respect to potential migrating substances using 1H-NMR, RP-HPLC-UV/ELSD and GC techniques. In all cases cyclic organosiloxane oligomers with the formula [Si(CH3)2-O]n were identified (n = 6 ... 50). Additionally, linear, partly hydroxyl-terminated organosiloxanes HO-[Si(CH3)2-O]n-H (n = 7 ... 20) were found in 13 samples. No substances other than siloxanes could be detected, meaning the migrants mainly consist of organopolysiloxanes. Based on this knowledge, a 1H-NMR quantification method for siloxanes was established for the analysis of both simulants and foodstuffs. Validation of the 1H-NMR method gave suitable performance characteristics: limit of detection 8.7 mg kg(-1) oil, coefficient of variation 7.8% (at a level of 1.0 mg kg(-1) food). Migration studies were carried out with simulants (olive oil, isooctane, ethanol (95%), Tenax) as well as preparation of different cakes. From the 1st to 10th experiment, siloxane migration into cakes only slightly decreased, with a significant dependence on fat content. Migration never exceeded a level of 21 mg kg(-1) (3 mg dm(-2)) and was, therefore, well below the overall migration limit of 60 mg kg(-1) (10 mg dm(-2)). However, migration behaviour into simulants differed completely from these results.