Bern University of Applied Sciences
Recent publications
In dryland ecosystems, tree and shrub seedling establishment, growth and survival are limited by access to water and nutrients. Arbuscular mycorrhizal fungi (AMF) increase seedling establishment and survival by enhancing nutrient and water acquisition. We executed a fully-factorial greenhouse experiment to determine the interactive effect of AMF (with and without), water deficit (four levels), and soil layer (topsoil and subsoil) on the biomass, growth, nutrient concentrations, and mycorrhizal root colonization of seedlings of Commiphora myrrha, a tree species that dominates large areas of dry forest and woodland in the Horn of Africa. Mycorrhizal seedlings had higher root and shoot biomass than non-mycorrhizal seedlings. They also had higher nutrient concentrations in root and shoot. Plant biomass was higher when plants were grown in topsoil at lower soil moisture levels. Mycorrhizal responsiveness was highest at lower soil moisture. The drought response index was higher for mycorrhizal than for non-mycorrhizal plants, indicating enhanced mycorrhizal benefits at lower water supply. Seedlings grew better in topsoil than in subsoil. Mycorrhizal colonization of roots of C. myrrha seedlings was higher with lower moisture and higher in topsoil than in subsoil. The increased performance of mycorrhizal C. myrrha indicates that mycorrhization is a major component of the adaptive strategy of seedlings of this species, similar to other species in these dryland deciduous ecosystems. We conclude that for restoration purposes with this species, nursery seedlings should be mycorrhized because of their enhanced growth performance.
In the present study, we analyze the relationship between domestic and international online publicity and individual outcomes of suspects in three recent politically salient cases in Russia. The analysis is based on the data from Telegram – one of the most politically relevant online platforms in contemporary Russia, – Google News and data about individual criminal cases. We find that international online publicity is associated with decreased likelihood of imprisonment for individual suspects, while the relationship between the latter and domestic publicity is less straightforward. Our findings contribute to the scholarship on the connection between (online) publicity and political repression relevant for Russia and, potentially, other autocracies.
Background: An outbreak of salmonellosis due to Salmonella Typhimurium was detected coincidentally in a Swiss meat rabbitry, given that surveillance of Salmonella in rabbits is not mandatory in Switzerland. Methods: To assess the extent of potentially subclinical Salmonella carriage in meat rabbits, faecal pool samples of 50 farms (90% of Swiss commercial rabbitries) with ground covering litter and group housing were bacteriologically tested. Additionally, 236 rabbits showing clinical signs compatible with intestinal diseases, such as salmonellosis, were examined postmortem and analysed bacteriologically. Salmonella isolates were serotyped and analysed by whole genome sequencing (WGS). Results: Salmonella Typhimurium was detected in three commercial farms (6.0% of all tested farms). The affected farms were directly linked to the animal trade and Salmonella isolates were shown to be identical by WGS. Conclusion: There is no increased hazard for Salmonella carriage in the animal welfare-friendly Swiss husbandry systems in general, despite risk factors such as ground covering litter.
Background The domestication of goat ( Capra hircus ) started 11,000 years ago in the fertile crescent. Breed formation in the nineteenth century, establishment of herd books, and selection for specific traits resulted in 10 modern goat breeds in Switzerland. We analyzed whole-genome sequencing (WGS) data from 217 modern goats and nine wild Bezoar goats ( Capra aegagrus ). After quality control, 27,728,288 biallelic single nucleotide variants (SNVs) were used for the identification of runs of homozygosity (ROH) and the detection of ROH islands. Results Across the 226 caprine genomes from 11 populations, we detected 344 ROH islands that harbor 1220 annotated genes. We compared the ROH islands between the modern breeds and the Bezoar goats. As a proof of principle, we confirmed a signature of selection, which contains the ASIP gene that controls several breed-specific coat color patterns. In two other ROH islands, we identified two missense variants, STC1: p.Lys139Arg and TSHR :p.Ala239Thr, which might represent causative functional variants for domestication signatures. Conclusions We have shown that the information from ROH islands using WGS data is suitable for the analysis of signatures of selection and allowed the detection of protein coding variants that may have conferred beneficial phenotypes during goat domestication. We hypothesize that the TSHR :p.Ala239Thr variant may have played a role in changing the seasonality of reproduction in modern domesticated goats. The exact functional significance of the STC1 :p.Lys139Arg variant remains unclear and requires further investigation. Nonetheless, STC1 might represent a new domestication gene affecting relevant traits such as body size and/or milk yield in goats.
Objective The combined use of action observation and motor imagery (AOMI) is a promising technique in neurorehabilitation that can be usefully applied in addition to conventional forms of therapy. Previous studies with healthy participants showed that the mere passive observation of walking results in a phase-dependent reflex modulation in the tibialis anterior muscle that resembles the pattern occurring when walking. In patients after stroke, a similar reflex modulation was found in several lower limb muscles during the real execution of walking, but responses were blunted. To clarify whether and how lower limb reflex responses are also modulated in such patients during the combined synchronous observation and imagery of walking, medium-latency cutaneous reflexes from the tibialis anterior muscle were measured. We compared the reflex responses of seven patients after stroke during the AOMI of walking from two different conditions: (a) elicited during the end stance phase and (b) during the end swing phase, both normalized to a baseline condition. Results So far, using the identical methodological set-up as in our study with healthy individuals, we could not find any noteworthy reflex response modulation. The study was registered with the German Clinical Trials Register (DRKS00028255). Trial registration : The study was registered with the German Clinical Trials Register: DRKS00028255.
The ability to predict the spatial distribution of tree root system variables (e.g., the Root system Area (RA), the maximum root diameter, the number of roots in diameter classes, the density of fine roots, etc.) under different environmental conditions is relevant to several scientific disciplines and to engineering practice. In this work, three well known analytical models from the literature are assembled into a unique framework called the Root Distribution Model (RDM). RDM models the expected vertical and horizontal distribution of coarse and fine root system variables for mature plants growing in different environmental conditions ranging from moderately humid to arid climates. All soil and moisture dynamic parameters are physically based, which make the model straightforward to calibrate via a single tuning parameter. At this investigative stage, it is shown that the model has the flexibility to represent a broad range of situations where soil moisture may result from precipitation inputs or from water level fluctuations due to either the presence of a water coarse or of deep aquifers or both. Accordingly, the distribution of the sectional RA may be either positively or negatively skewed, as well as show a peculiar bi-modal structure. The model can be used to study the impact of changing scenarios affecting precipitation, aquifer and channel hydrology.
We propose the usage of two power indices from cooperative game theory and public choice theory for ranking attributes of closed sets, namely intents of formal concepts (or closed itemsets). The introduced indices are related to extensional concept stability and are also based on counting of generators, especially of those that contain a selected attribute. The introduction of such indices is motivated by the so-called interpretable machine learning, which supposes that we do not only have the class membership decision of a trained model for a particular object, but also a set of attributes (in the form of JSM-hypotheses or other patterns) along with individual importance of their single attributes (or more complex constituent elements). We characterise computation of the Shapley and Banzhaf-Penrose values of a formal concept in terms of minimal generators and their order filters, provide the reader with their properties important for computation purposes, prove related #P-completeness results, and show experimental results with model and real datasets. We also show how this approach can be applied in both supervised (classification) and unsupervised (pattern mining) settings.
Despite broad consensus on the importance of measuring “impact,” the term is not always understood as estimating counterfactual and causal estimates. We examine a type of public sector financing, “Social Impact Bonds,” a scheme where investors front money for public services, with repayment conditional on impact. We examine five cases in four European countries of Social Impact Bonds financing active labor market programs, testing the claim that Social Impact Bonds would move counterfactual causal impact evaluation to the heart of policy. We examine first how evidence was integrated in contracts, second the overall evidence generated and third, given that neither contracts nor evaluations used counterfactual definitions of impact, we explore stakeholders’ perspectives to better understand the reasons why. We find that although most stakeholders wanted the Social Impact Bonds to generate impact estimates, beliefs about public service reform, incentives, and the logic of experimentation led to the acceptance of non-causal definitions.
Background No randomised controlled study (RCT) on the effectiveness of Independent Supported Housing (ISH) vs. housing as usual (HAU) settings for non-homeless individuals with severe mental illness (SMI) has been conducted to date because of limited feasibility. Alternative designs, such as observational studies, might be suitable for providing adequate evidence if well conducted. To test this hypothesis, this article reports on a prospective, direct comparison of the designs of two parallel studies in this field. Methods A two-centre, parallel-group non-inferiority effectiveness study was conducted at two locations in Switzerland using identical instruments and clinical hypotheses. One centre applied an RCT design and the other an observational study (OS) design with propensity score methods ( : NCT03815604). The comparability of the two study centres was investigated in terms of participants, procedures, and outcomes. The primary outcome was social inclusion and the secondary outcomes were quality of life and psychiatric symptoms. Results The study included 141 participants (RCT: n = 58; OS: n = 83). Within one year, 27% study dropouts occurred (RCT: 34%; OS: 22%). A similar balance of sample characteristics was achieved in the RCT and the OS using propensity score methods (inverse probability of treatment weighting). After one year, ISH was non-inferior to the control condition regarding social inclusion (mean differences [95% CI]) in the RCT (6.28 [–0.08 to 13.35]) and the OS (2.24 [–2.30 to 6.77]) and showed no significant differences in quality of life (RCT: 0.12 [–0.52 to 0.75]; OS: 0.16 [–0.26 to 0.58]) and symptoms (RCT: –0.18 [–0.75 to 0.40]; OS: 0.21 [–0.17 to 0.60]) in both study centres. However, strong and persistent preferences for ISH in the RCT control group reduced participants’ willingness to participate. Because of several limitations in the RCT, the results of the RCT and the OS are not comparable. Conclusion Participants were comparable in both study sites. However, there were significant problems in conducting the RCT because of strong preferences for ISH. The OS with propensity score methods provided results of more stable groups of participants and revealed balanced samples and valid outcome analysis. Our results do not support further investment in RCTs in this field.
This partially randomised controlled, crossover study sought to investigate the effects of normobaric hypoxia (NH) and hypobaric hypoxia (HH) on cognitive performance, the physiological response at rest and after a 3-min step-test. Twenty healthy participants (10 females and 10 males, 27.6±6.2yrs, 73.6±13.7kg, 175.3±8.9cm) completed a cognitive performance test, followed by the modified Harvard-step protocol, in four environments: normobaric normoxia (NN; P i O 2 : 146.0±1.5mmHg), NH (P i O 2 : 100.9±1.3mmHg), HH at the first day of ascent (HH1: P i O 2 = 105.6±0.4mmHg) and HH after an overnight stay (HH2: P i O 2 = 106.0±0.5mmHg). At rest and/or exercise, SpO 2 , NIRS, and cardiovascular and perceptual data were collected. The cerebral tissue oxygenation index and the cognitive performance (throughput, accuracy, and reaction time) were not different between the hypoxic conditions (all p>0.05). In NH, SpO 2 was higher compared to HH1 (ΔSpO 2 NH vs HH1: 1.7±0.5%, p = 0.003) whilst heart rate (ΔHR NH vs HH2: 5.8±2.6 bpm, p = 0.03) and sympathetic activation (ΔSNSi NH vs HH2: 0.8±0.4, p = 0.03) were lower in NH compared to HH2. Heart rate (ΔHR HH1 vs HH2: 6.9±2.6 bpm, p = 0.01) and sympathetic action (ΔSNSi HH1 vs HH2: 0.9±0.4, p = 0.02) were both lower in HH1 compared to HH2. In conclusion, cognitive performance and cerebral oxygenation didn’t differ between the hypoxic conditions. SpO 2 was only higher in NH compared to HH1. In HH2, heart rate and sympathetic activation were higher compared to both NH and HH1. These conclusions account for a P i O 2 between 100–106 mmHg.
Objective The primary objective of this observational study was to analyze the time to the first edge-of-bed (EOB) mobilization in adults who were critically ill with severe versus non-severe COVID-19 pneumonia. Secondary objectives included the description of early rehabilitation interventions and physical therapy delivery. Methods All adults with laboratory-confirmed COVID-19 requiring intensive care unit admission for ≥72 hours were included and divided according to their lowest PaO2/FiO2 ratio into severe (≤ 100 mmHg) or non-severe (> 100 mmHg) COVID-19 pneumonia. Early rehabilitation interventions consisted of in-bed activities, edge-of-bed or out-of-bed mobilizations, standing, and walking. The Kaplan–Meier estimate and logistic regression were used to investigate the primary outcome time-to-EOB and factors associated with delayed mobilization. Results Among the 168 patients included in the study (mean age = 63 y [SD = 12 y]; Sequential Organ Failure Assessment [SOFA] = 11 [IQR 9–14]), 77 (46%) were classified as non-severe and 91 (54%) were classified as severe COVID-19 pneumonia. Median time-to-EOB was 3.9 days (95% CI = 2.3–5.5) with significant differences between subgroups (non-severe = 2.5 days [95% CI = 1.8–3.5]; severe = 7.2 days [95% CI = 5.7–8.8]). Extracorporeal membrane oxygenation (ECMO) use and high SOFA scores (adjusted effect = 13.7 days [95% CI = 10.1–17.4] and 0.3 days [95% CI = 0.1–0.6]) were significantly associated with delayed EOB mobilization. Physical therapy started within a median of 1.0 days (95% CI = 0.9–1.2) without subgroup differences. Conclusions This study shows that early rehabilitation and physical therapy within the recommended 72 hours during the COVID-19 pandemic could be maintained regardless of disease severity. In this cohort, the median time-to-EOB was fewer than 4 days, with disease severity and advanced organ support significantly delaying the time-to-EOB. Impact Early rehabilitation in the intensive care unit could be sustained in adults who are critically ill with COVID-19 pneumonia and can be implemented with existing protocols. Screening based on PaO2/FiO2 ratio might reveal patients at risk and increased need for physical therapy.
Physical activity, particularly walking, is commonly used for the treatment of diseases such as low back pain. In this study, the effects of walking wearing the new ToneFit Reha training belt (TFR) were compared to both Nordic walking and regular walking. The TFR is intended to intensify the effects of walking through the integration of two adjustable resistance handles. Ten patients with low back pain performed regular walking, Nordic walking and walking with the TFR in a movement laboratory. The kinematics of the trunk, upper extremities and lower extremities were measured, and the activity of the trunk and upper extremity muscles recorded. Data were analysed by repeated-measures ANOVA and paired t-test. Kinematics indicated that walking with the TFR introduces instability that was mitigated by a delayed peak trunk rotation (peak at 63.3% gait cycle, vs. 52.8% in walking (p=0.001) and 51.0% in NW (p=0.007)). Upper extremity kinematics (constrained elbow flexion, high peak shoulder abduction) showed movement patterns that need to be considered when training over a longer period. Increased muscle activity was observed especially for upper extremity muscles, when training with TFR. Overall, walking with the TFR was found to be a suitable therapy for use in a rehabilitation setting.
Background Healthcare is facing a shortage of qualified healthcare professionals. The pandemic has brought to light the fragile balance that affects all healthcare systems. Governments have realized that these systems and the professionals working in them need support at different levels to strengthen the retention of the workforce. Health professionals’ education can play an important role in ensuring that new generations of workers have sound personal and professional competencies to successfully face the challenges of professional practice. These challenges are described in the literature, but the extent to which they are considered in health professionals’ education is less clear. Methods This qualitative study compares the professional challenges and educational needs described in the literature with the current curricula for health professionals offered in Switzerland. Data were collected nationally through focus group interviews with 65% of Switzerland’s directors of bachelor’s and master’s programs of health professions (nursing, physiotherapy, occupational therapy, midwifery, nutrition and dietetics, osteopathy, radiologic medical imaging technology, health promotion and prevention, and health sciences). The data attained were analyzed using knowledge mapping. Results The results reveal a gap among education programs with regard to occupational health promotion and cultural diversity. Both topics are taught with a sole focus on patients, and students are expected to adopt similar strategies for their health promotion and stress management. Physicians are insufficiently involved in interprofessional education. The programs fail to enhance health professionals’ political, economic and digital competencies. Conclusion The results of this study offer clear guidance about what topics need to be integrated into curricula to improve health professionals’ well-being at work and their preparedness to face daily professional challenges.
Evaluating conversational agents (CA) that are supposed to be applied in healthcare and ensuring their quality is essential to avoid patient harm. However, most researchers only study usability and use the CA in clinical trials before conducting such careful evaluation. In previous work, consensus on metrics for evaluating healthcare CA have been found. However, the metrics are still too generic to form an evaluation framework. In this work, we try to link the ISO technical specification ISO/TS 82304-2 Quality Requirements for Health and Wellness Apps to the set of metrics to come a step closer towards an evaluation framework. We identify three links between ISO requirements and the set of metrics, namely accessibility, usability, and security. Although the technical specification rather lists aspects to be considered during development instead of concrete metrics for studying the quality, we can link to some aspects that are also of interest for health CA evaluation. For example, measuring the readability for ensuring accessibility or implementing the Web Content Accessibility Guidelines are two aspects of relevance for health CA.
Soil visible-near infrared (vis–NIR) spectra are complex and modeling soil properties can be challenging. They can suffer from additive and multiplicative noise, they are hyper-dimensional and highly collinear, making their analyses and interpretation sometimes difficult. Here, we introduce the Gaussian pyramid scale space as a multi-resolution approach for denoising spectra, reducing dimensionality, and improving the interpretability and accuracy of spectroscopic machine learning. We also used the approach to analyse contextual interactions between different resolutions and the stability of feature importance across different resolutions. Using an Australian data set and the German data in the LUCAS spectral database we found that with a single Gaussian scale that represents a relatively coarse spectral resolution, we could estimate organic carbon, clay and pH as accurately as with multiple Gaussian scales, or using all resolutions. This indicates that, in the vis–NIR range, there are no relevant interactions between resolutions, which simplifies interpretations. We conclude that the Gaussian pyramid scale space can help to model soil properties with spectral machine learning, improving both accuracy and interpretability. Because the Gaussian pyramid approach is computationally efficient, it can also be used for preprocessing and knowledge discovery before more elaborate modeling is applied.
The Swiss classification of surgical interventions (CHOP) has to be used in daily practice by physicians to classify clinical procedures. Its purpose is to encode the delivered healthcare services for the sake of quality assurance and billing. For encoding a procedure, a code of a maximal of 6-digits has to be selected from the classification system, which is currently realized by a rule-based system composed of encoding experts and a manual search in the CHOP catalog. In this paper, we will investigate the possibility of automatic CHOP code generation based on a short query to enable automatic support of manual classification. The wide and deep hierarchy of CHOP and the differences between text used in queries and catalog descriptions are two apparent obstacles for training and deploying a learning-based algorithm. Because of these challenges, there is a need for an appropriate classification approach. We evaluate different strategies (multi-class non-terminal and per-node classifications) with different configurations so that a flexible modular solution with high accuracy and efficiency can be provided. The results clearly show that the per-node binary classification outperforms the non-terminal multi-class classification with an F1-micro measure between 92.6 and 94%. The hierarchical prediction based on per-node binary classifiers achieved a high exact match by the single code assignment on the 5-fold cross-validation. In conclusion, the hierarchical context from the CHOP encoding can be employed by both classifier training and representation learning. The hierarchical features have all shown improvement in the classification performances under different configurations, respectively: the stacked autoencoder and training examples aggregation using true path rules as well as the unified vocabulary space have largely increased the utility of hierarchical features. Additionally, the threshold adaption through Bayesian aggregation has largely increased the vertical reachability of the per node classification. All the trainable nodes can be triggered after the threshold adaption, while the F1 measures at code levels 3–6 have been increased from 6 to 89% after the threshold adaption.
Personal recovery is important for mental health services and service users; moreover, valid and reliable assessment instruments are necessary for measuring personal recovery. Therefore, this study aimed to evaluate the unidimensional factor structure of the German version of the Questionnaire about the Process of Recovery. The study was conducted using a cross‐sectional design with a convenience sample. The questionnaire was completed by 200 patients of outpatient services of two psychiatric hospitals in Switzerland. A confirmatory factor analysis was conducted to validate the unidimensional factor structure of the German version of the Questionnaire about the Process of Recovery. Cronbach's alpha was calculated to assess the internal consistency. The results showed an overall acceptable model fit (χ2 = 134.188, df = 90, P = 0.002; RMSEA = 0.050, 90% CI: 0.031–0.067; CFI = 0.937; TLI = 0.927) and excellent internal consistency (Cronbach's α = 0.91). These results are consistent with those of studies that have examined the Questionnaire about the Process of Recovery in other languages. This study provides preliminary evidence that the German version of the Questionnaire about the Process of Recovery is a reliable assessment instrument for measuring personal recovery among people with mental illness experiences. However, it is necessary to conduct further psychometric tests to verify the validity and reliability of the instrument. The German version of the Questionnaire about the Process of Recovery can be applied to both research and clinical practice, especially as a means of facilitating communication during the planning and evaluation of treatment goals.
We study the formation of laser-induced periodic surface structures (LIPSS) on diamond-like nanocomposite (DLN) a-C:H:Si:O films and titanium-doped DLN films during femtosecond (fs) laser ablation processing with linearly-polarized beams of IR and visible fs-lasers (wavelengths 1030 nm and 515 nm, pulse duration 320 fs, pulse repetition rates 100 kHz-2 MHz, scanning beam velocity 0.04–0.4 m/s). The studies are focused on (i) comparison of high spatial frequency LIPSS (HSFL) and low spatial frequency LIPSS (LSFL) formed on DLN and Ti-DLN films by IR fs-laser processing, (ii) effects of the pulse repetition rate on the parameters of LIPSS formed on the DLN and Ti-DLN films, (iii) Raman spectroscopy analysis of the LIPSS-structured films with application for ultrathin surface graphitization, and (iv) relationship between the fs-laser-induced surface graphitization and LIPSS formation on the films. A variety of the HSFL and LSFL have been produced on the surface of DLN and Ti-DLN films, with all the LIPSS being oriented perpendicular to the beam polarization direction. The HSFL periods are varied from ~80 to 240 nm and the LSFL periods are varied from 355 to 840 nm, depending on the fs-laser irradiation conditions (wavelength, fluence, pulse repetition rate) and films properties. Various plasmonic effects such as the superposition of the HSFL and LSFL and emergence of very unusual sinusoid-like structures on the DLN and Ti-DLN films are presented and discussed.
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3,772 members
Sebastian Gurtner
  • Business School
Nikolaus Obwegeser
  • Business School
Hanna Hölling
  • Bern Academy of the Arts
Kerstin Denecke
  • Department of Engineering and Information Technology
Stefan Schmid
  • Department of Health Professions
Falkenplatz 24, 3012, Bern, Switzerland