Norwegian University of Science and Technology

This paper deals with two major challenges in population-based structural health monitoring (PBSHM) for critical infrastructures, with focus on bridges. The first challenge is related to training a collaborative model based on local datasets from different bridges under privacy-preserving constraints. The second challenge is related to the (potential) limited amount of data and/or resources available locally at some bridges. To address these issues, we propose a framework based on clustered federated learning (CFL) for efficient and collaborative training of monitoring models while preserving data privacy. The approach leverages the concept of principal angles (PAs) to cluster the bridges according to their data distributions without domain-based prior information. Cluster-specific models are then trained efficiently according to the available local resources. Moreover, the proposed framework allows the integration of new bridges providing quick and resource-efficient knowledge transfer from the cluster-specific parameters to the infrastructure-specific parameters. Numerical results based on extensive simulations show that the proposed framework performs well, both within supervised and unsupervised settings, yielding more accurate results than traditional schemes.

The philosophical foundations of statistics involve issues in theoretical statistics, such as goals and methods to meet these goals, and interpretation of the meaning of inference using statistics. They are related to the philosophy of science and to the philosophy of probability.

A movement towards reduced grading practices has emerged internationally over the past few decades. Reduced grading refers to approaches aimed to limit the use and emphasis of grades in assessment, which has been shown to affect stakeholders differently and introduces unpredicted challenges (Normann et al., 2023). The movement has been embraced in various educational contexts; however, little is known about stakeholders’ perceptions of this shift away from grading. Analysing interviews with nine vocational teachers using thematic analysis (Braun & Clarke, 2021a), this study explores dilemmas encountered by teachers when implementing reduced grading. The study conceptualises teachers’ ambivalence towards reduced grading as a dilemma and outlines (1) the dilemma of being faithful or truthful (i.e., adhering to policy vs. ensuring transparency for students) and (2) how navigating the faithful-truthful dilemma was stressful for teachers. The concept of being faithful encompasses teachers’ professional loyalty in the form of adhering to policies, whilst being truthful involves focusing their professional loyalty towards students’ assessment needs. Balancing the dilemma is not an easy task. Grappling with the ideals of being faithful or truthful may create challenges for teachers’ professional loyalty, potentially leading to new sources of stress among teachers of not being able to document students’ learning and defend final grade justifications. A discussion and the implications for research, practice and policy are provided.

Background Children with juvenile idiopathic arthritis (JIA) are at risk for impaired bone health. This study evaluates bone mineral density (BMD) and potential risk factors for reduced BMD. Methods In the NorJIA study, Norwegian children with JIA, and age-matched and sex-matched controls participated in a multicentre cohort study with clinical examinations, questionnaires, imaging and blood tests. BMD was measured using dual-energy X-ray absorptiometry and adjusted for bone age. Standard descriptive statistics and t-tests were used. Results 205 children with JIA had BMD measured at two study visits, 2 years apart and 125 controls at the second visit. At visit 2, median age was 14.7 years (IQR 11.5–16.6). Median disease duration was 6.6 (IQR 4.7–10.4) years, 50.7% had used or were currently using biologic disease-modifying antirheumatic drugs and 25.9% had ever used systemic steroids. There were no substantial differences in BMD Z-scores between the JIA group and controls. Mean BMD Z-score L1-L4 in JIA was 0.0 (95% CI −0.1, 0.1) and in controls 0.1 (95% CI −0.1, 0.3). A robust association was seen between physical activity levels and BMD. In children with JIA, the mean BMD Z-score L1-L4 was −0.3 (95% CI −0.6, 0.0) in the low-activity group and 0.2 (95% CI 0.0, 0.4) in the high-activity group, with a similar trend in controls. Children with JIA were as physically active as controls. Conclusions BMD Z-scores in JIA were similar to controls and positively associated with physical activity. This underlines the importance of early disease control, steroid-sparing medications and physical activity to optimise bone health. Trial registration number NCT03904459.

Wildlife populations globally have experienced widespread historical declines due to anthropogenic and environmental impacts, yet for some species, contemporary management and conservation programmes have enabled recent recovery. The impacts of decline and recovery on genomic diversity and, vice versa, the genetic factors that contribute to conservation success or failure are rich areas for inquiry, with implications for shaping how we manage species into the future. To comprehensively characterise these processes in natural systems requires range‐wide sampling and international collaboration, particularly for species with wide dispersal capabilities, broad geographic distributions, and complex regional metapopulation dynamics. Here, we present the first range‐ and genome‐wide population genomic analysis of grey seals based on 3812 nuclear SNPs genotyped in 188 samples from 17 localities. Our analyses support the existence of three main grey seal populations centred in the NW Atlantic, NE Atlantic and Baltic Sea, and point to the existence of previously unrecognised substructure within the NE Atlantic. We detected remarkably low levels of genetic diversity in the NW Atlantic population, and demographic analyses revealed a turbulent history of NE Atlantic and Baltic Sea grey seals, with bottlenecks in the Middle Ages and the 20th century due to hunting and habitat alterations. We found some localities deviated from isolation by distance patterns, likely reflecting wide‐scale metapopulation dynamics associated with recolonisation and recovery in regions where they were historically extirpated. We identify at least six grey seal genetic populations and reveal marked genetic effects of past declines and recent recovery across the species' range.

Background Although evidence for exercise-induced changes in neurocognitive biomarkers is emerging, research examining acute responses to different exercise regimes across sex and age is lacking. This study investigated serum concentrations of three neurocognitive biomarkers (i.e., Klotho, brain-derived neurotrophic factor (BDNF), and glycosylphosphatidylinositol-specific phospholipase D1 (GPLD1)) after acute strength and aerobic exercise, along with skeletal muscle gene expression. Methods In a within-subjects crossover design, blood samples of 19 young women, 20 young men, and 14 elderly men were taken before, immediately, 3 h and 24 h after one bout of strength training (ST) and high-intensity interval training (HIIT). Muscle biopsies were taken from a subgroup (n = 22) before, 3 h and 24 h after ST and HIIT for gene expression analyses. Time changes and baseline levels, including the influence of sex and age, were analyzed using a multilevel model and Welch’s analysis of variance, respectively. Biomarker levels were adjusted for exercise-induced plasma volume changes. Results Serum concentration of all biomarkers increased after ST and HIIT but were not affected by sex or age. While serum Klotho and BDNF levels peaked immediately after exercise in all groups, serum GPLD1 levels were highest at 3 h (young groups only). Age was a determining factor for baseline measures; young men had higher and lower resting serum Klotho and BDNF concentration, respectively, than elderly men. Muscle gene expression of Klotho increased after both exercise modes, and BDNF and GPLD1 expression was reduced within 24 h. Conclusions Circulating levels of biomarkers linked to brain health can acutely be increased by one bout of ST or HIIT. This increase might be related to altered gene expression of these proteins in skeletal muscle. Ultimately, this could have beneficial implications for the management of mental and neurocognitive impairments.

We prove a thick subcategory theorem for the category of d-excisive functors from finite spectra to spectra. This generalizes the Hopkins–Smith thick subcategory theorem (the d=1 case) and the $C_{2}$-equivariant thick subcategory theorem (the d=2 case). We obtain our classification theorem by completely computing the Balmer spectrum of compact d-excisive functors. A key ingredient is a non-abelian blueshift theorem for the generalized Tate construction associated to the family of non-transitive subgroups of products of symmetric groups. Also important are the techniques of tensor triangular geometry and striking analogies between functor calculus and equivariant homotopy theory. In particular, we introduce a functor calculus analogue of the Burnside ring and describe its Zariski spectrum à la Dress. The analogy with equivariant homotopy theory is strengthened further through two applications: We explain the effect of changing coefficients from spectra to ${\operatorname{H}\hspace {-0.2em}\mathbb{Z}}$-modules and we establish a functor calculus analogue of transchromatic Smith–Floyd theory as developed by Kuhn–Lloyd. Our work offers a new perspective on functor calculus which builds upon the previous approaches of Arone–Ching and Glasman.

The sea surface and air–sea exchange processes have been identified as essential for both short- and long-term atmospheric and ocean forecasts. The two phases of the fluid layer covering our planet interact across a vast range of scales that we need to explore to achieve a better understanding of the exchange processes. While satellites provide a distributed large-scale view of the sea surface situation, highly detailed measurements, e.g., from oceanographic towers, are necessarily local. An intermediate solution can be provided by swarms of miniature surface buoys that measure waves and other key parameters. As size, weight, and cost are reduced, these can be deployed in large numbers to investigate specific processes that are at present only crudely parameterized in our models, also because of the scarcity of good measurements. Perhaps the most crucial process is white capping in stormy conditions, where air–sea exchanges are enhanced by one or two orders of magnitude. Other applications include wave–current interactions, wave–ice interactions, and plunging breakers in the coastal zone. Stimulated by a dedicated workshop, we summarize here the main findings and possibilities derived from the different approaches and, in particular, the state of the art for a selection of miniature buoys. We list the presented solutions, as well as other, similar and larger, buoys, with their main characteristics and range of application. We describe the various possibilities of practical use and the scientific and engineering problems to be solved. Looking to the future, we also point out where the present technological improvements are leading to.

Background Proinflammatory cytokines are central to disease mechanisms and important therapeutic targets in inflammatory chronic diseases. This exploratory study aimed to compare cytokine concentrations in saliva, serum, and temporomandibular joint (TMJ) synovial fluid in children with juvenile idiopathic arthritis (JIA) and controls. Methods In this cross-sectional study, we included consecutive children with JIA and TMJ arthritis, planned for a TMJ corticosteroid injection, and non-JIA controls from three different centers in Norway. Data on demographics, disease activity, presence of TMJ arthritis, and medication were obtained. Samples of unstimulated saliva, serum, and TMJ synovial fluid were collected. The amount of recovered synovial fluid in each sample, collected by the push-and-pull technique, was quantified with the hydroxocobalamin method. Cytokine levels were analyzed using Luminex xMAP technology. Results Fifteen patients with JIA and TMJ arthritis (JIA-TMJ) (median age 15.0 (interquartile range (IQR) 11.0–16.0) years) and 34 controls (median age 13.0 (IQR 9.8–15.0) years) were consecutively recruited. Samples of saliva (JIA-TMJ, n = 13, and controls, n = 28), serum (JIA-TMJ, n = 11, and controls, n = 16), and TMJ synovial fluid (JIA-TMJ, n = 8) were collected. In saliva from JIA-TMJ, we found significantly higher levels of the cytokines IL-1β, IL-4, IL-5, IL-9, IL-10, IL-12, IL-13, IL-17, Eotaxin, FGF basic, GM CSF, PDGF bb, TNF, and RANTES, while IP-10 was found in significantly lower concentration compared to controls. In serum, there were no significant differences in these cytokine concentrations between JIA-TMJ and controls. Three TMJ synovial samples fulfilled the strict sampling criteria and were included in the analysis. The level of detected cytokines in TMJ synovial samples was higher in JIA-TMJ compared to controls, as described in a previous Nordic study. Conclusions In this exploratory study, several proinflammatory cytokines were found in higher concentrations in saliva in JIA-TMJ compared to saliva from the controls. No differences were seen in serum between the groups. Some pro- and anti-inflammatory cytokines detected in JIA-TMJ synovial fluid were found in higher concentrations compared to TMJ synovial fluid from healthy adult reference data.

Purpose To explore the challenges and opportunities for the implementation of falls preventive services across Europe. Methods An online cross-sectional survey among healthcare professionals was initiated by the European Geriatric Medicine Society (EuGMS) Special Interest Group on Falls and Fractures containing a Likert scale and multiple-choice questions on education and knowledge, current practices, barriers, and facilitators for falls prevention. Survey participation for healthcare professionals was encouraged by the EuGMS through an email invitation, website banner, and social media. National representatives from 24 countries further promoted it via societies, local networks, and hospital channels. Results A total of 1669 multidisciplinary healthcare professionals participated from 34 European countries (median 47 years; 75% female; 40.6% physicians (73.3% geriatricians/trainees), 36% physiotherapists, 23.4% other healthcare professionals). Only 26.9% believed their undergraduate education adequately prepared them for clinical practice in this area. A total of 75.8% of respondents reported opportunistically screening older adults for fall risk often or always during consultations. Gait and balance assessment was considered the most important and was the most frequently performed component of the multifactorial fall risk assessment. The top-five barriers were staffing issues, lack of time, older adults' non-adherence to recommended strategies, workload related to falls prevention, and prioritizing other tasks. The top-five facilitators were more time, easy-to-use guidelines, sufficient resources, increased education and training on falls prevention, and increased collaboration. We observed regional and country-level variation in these top barriers and facilitators. Conclusion This survey highlights the need for improved undergraduate education in falls prevention across Europe. It is essential to educate and engage governmental bodies and insurers to secure their support and prioritization of falls prevention initiatives. Furthermore, enhancing education, addressing older adults' nonadherence, interdisciplinary collaboration and providing easy-to-use guidelines seem crucial for effective implementation. The falls prevention strategy should be tailored to the local context.

The COVID-19 pandemic highlighted the need to improve ICU capacity and working conditions in Norwegian hospitals and recruit and retain nurses. The aim of this study is to explore what motivates nurses to continue working in the ICU using a constructivist approach, asserting that knowledge is created through the interaction between the researcher, the participants, and the context. Eight individual semi-structured interviews with intensive care nurses were audio-recorded and transcribed verbatim. The data were analysed using thematic analysis. We identified one main overarching theme, “an interpersonal and professionally focussed work environment,” highlighting how a supportive and professional atmosphere boosts intensive care nurses’ job satisfaction and motivation, and three subthemes. The sub-themes were named: “unity and well-being,” underscoring the need for professional and interpersonal support, “close and professional leadership,” emphasising the importance of having an attentive, accessible, and unifying leader, and “professional engagement and mastery,” focussing on the significance of training, continuous skill development, and task distribution based on competence and experience. This study adds new knowledge about environmental factors that contribute to the understanding of why intensive care nurses remain in their profession and their motivation to continue working in the ICU despite the high workload.

Low-level mixed-phase clouds occur frequently and persistently in the central Arctic and thus play a key role in climate feedback mechanisms, airmass transformations, and sea ice melt. Turbulent entrainment at cloud top driven by radiative cooling modulates these clouds by affecting the boundary layer heat budget. However, reliable measurements of this small-scale process are scarce. This study presents new insights into entrainment in radiatively driven cloudy mixed layers at high latitudes based on a library of daily large-eddy simulations covering the full Multidisciplinary Drifting Observatory for the Study of Arctic Climate (MOSAiC) drift. The simulations are based on measurements, cover a periodic and homogeneously forced small domain representing conditions observed at the Polarstern research vessel, and resolve Arctic turbulence and clouds to a high degree. Approximately 1 out of 3 simulated days contains cloud mass in the liquid phase. A drift-average heat budget analysis shows that the bulk cloud-topped mixed layer is dominated by radiative cooling. Warming by top entrainment partially counters this cooling, at efficiencies of about 21%. While this compensation is significant, such efficiencies are also much lower compared to previous findings for subtropical warm marine stratocumulus. Interestingly, a few outlying MOSAiC cases show similarly high efficiencies. Analysis of turbulence energetics and dedicated sensitivity experiments reveals that high entrainment efficiency can be achieved in two ways: surface coupling and strong local wind shear. The former explains the high efficiencies in the subtropics, while the latter drives the highest efficiencies encountered during MOSAiC. In general, these findings emphasize the important role played by wind shear in boosting entrainment efficiency. Significance Statement Stratocumulus cloud layers in the high Arctic often contain liquid water at subzero temperatures. Such cloud layers cool rapidly through radiation, a process that locally creates turbulence. This turbulence causes mixing in the atmosphere. Using many high-resolution atmospheric model simulations on a supercomputer, we investigate how this mixing process causes warming in the cloud layer. The simulations are closely based on measurements made during the recent yearlong Multidisciplinary Drifting Observatory for the Study of Arctic Climate (MOSAiC) drift experiment. We find that the warming only partially counteracts the radiative cooling and that a strong change in the wind with height can affect this balance.

Emergency dispatchers are required to remain calm and focused, managing complex and intense situations when allocating resources and providing information to first responders on site. However, despite their importance in securing public safety, the working conditions of emergency dispatchers have received marginal attention. This study addresses this gap by exploring: (1) “How do police emergency dispatchers experience their working conditions?” and (2) “Which initiatives do the emergency dispatchers suggest for reducing stress, improving the working conditions, and promoting health maintenance?” We applied qualitative content analysis to responses from 78 police emergency dispatchers to open‐ended questions from an online survey. The work's demanding and intense nature is regarded as both stressful and engaging. Cumulative stress is perceived as more challenging than dramatic incidents. Noise and suboptimal technical solutions add to the burden. Lack of follow‐up, understaffing and turnover may be depicted as a vicious circle that could be counterbalanced by more staff, outsourcing of redundant tasks, better technical equipment, and leadership‐initiated debriefing. Although limitations apply, the results from this study are important for practitioners and researchers within the field of operative psychology and emergency dispatchers. The results can contribute to an improved work environment, work culture, training, well‐being, and performance of police emergency dispatchers, which can increase job performance as well as effectiveness and, consequently, secure public safety.

This paper presents an instrumentation system that maps sea ice fields from ships using a LiDAR sensor and an optical camera. The output is a multimodal point cloud containing 3D coordinates, LiDAR intensity values, and RGB colors from the camera. The system is designed to be completely independent of the ship it is mounted on, making it a scalable solution for in-situ sea ice analysis with minimal installation effort. To achieve this, a GNSS-aided inertial navigation system is developed to estimate the system’s trajectory during transit. The navigation system uses a factor graph approach to perform full-trajectory smoothing and integrates a novel method to include motion constraints from the ship’s dynamics. Specifically, we model how orientation changes are reflected as position displacements caused by a lever arm between the ship’s center of rotation and the instrumentation system. The navigation system is evaluated against ship navigation data, and results indicate that the system pose estimates align well with the ship estimates. The resulting ice maps are validated by comparing rendered point cloud images with photographs captured by the system camera. Using this technique, the presented examples illustrate how the generated point clouds provide insights into properties such as ice deformation, surface reflectivity, and color.

As containerships continue to increase in size, liner networks have evolved into spoke network structures, with the integration of deep-sea main routes and regional feeder routes. Taking into account the practical context of the domestic piggyback (DP) policy in China, this paper addresses joint operations between two different providers of deep-sea main routes and regional (domestic) feeder routes, respectively. The resulting planning problem is denoted the liner feeder shipping network design problem (LFSNDP) with joint operations under the DP policy, which involves decisions about hub port location, feeder network design, and fleet deployment. We propose a mixed-integer programming (MIP) model for the LFSNDP. Furthermore, we extend this model to the LFSNDP-MAH (multiple allocation hub), which considers multi hub-allocation and cargo splitting. The two models can be solved using a commercial MIP-solver with a number of candidate main and feeder route combinations generated as input. Finally, we conduct experiments on instances based on a real case study to provide managerial insights. The results show that the LFSNDP model can solve the network design problem with cargo piggybacking, while we show that the LFSNDP-MAH, based on multi-allocation of hubs and cargo splitting, can reduce operation cost by rebalancing cargo flows.