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Fractional differential problems with numerical anti-reflective boundary conditions from a numerical linear algebra perspective : A computational study with an extensive numerical validation
No full textIn the current work, we propose numerical anti-reflective boundary conditions (BCs) in the context of nonlocal problems of fractional differential type: the numerical linear algebra goal is a O(N log N) complexity of the resulting direct and iterative algorithms, accompanied by a qualitative better approximation, with the mitigation of boundary artifacts. In fact, for showing the quality of the numerical anti-reflective BCs, we compare various types of numerical BCs, including the anti-symmetric ones considered in the case of fractional differential problems for modeling reasons. More in detail, given important similarities between anti-symmetric and anti-reflective BCs, we compare them from the perspective of computational efficiency, by considering non-truncated and truncated versions, and also other standard numerical BCs such as periodic BCs or reflective/Neumann BCs. A short theoretical analysis and several numerical tests, tables, and visualizations are provided and critically discussed. The conclusion is that the truncated numerical anti-reflective BCs perform better, both in terms of low computational cost and accuracy
Timing of MRI for early treatment response prediction of chemoradiotherapy in uterine cervical cancer
No full textAim: To explore the optimal use of MRI including time point to predict early treatment response during definitive chemoradiotherapy in cervical carcinoma. Methods: Pilot study including 15 patients with cervical carcinoma stage IIB-IIIB (FIGO 2009) scheduled for chemoradiotherapy. All patients underwent four MRI examinations (at baseline, 3 weeks, 5 weeks, and 12 weeks after treatment start). Maximum tumor size, size change (Delta size), visibility on diffusion-weighted imaging (DWI), apparent diffusion coefficient (ADC) mean and change in ADC (Delta ADC) at the different time points were recorded. Results: 7/15 patients relapsed during the study period, referred to as "poor prognosis" (PP) and the remaining 8/15 are referred to as "good prognosis" (GP). At all four time points, the tumors in the PP patients were larger than in the GP patients. Tumor size did change between the time point but this was not significant between the groups. Visible tumor on high b-value DWI reached a sensitivity and specificity for predicting prognostic group being highest at 5 weeks, 83 % (5/6) and 63 % (5/ 8), respectively. The combination of tumor size at baseline and visible tumor on DWI at 5 weeks, resulted in an area under the curve (AUC) = 0.83. At 12 weeks, no GP patients, but 2/7 PP patients showed visible tumor on DWI. Addition of ADC-values in the analysis did not improve the predictive value at any time point. Conclusion: This pilot study indicates that the tumor size on baseline MRI, combined with tumor visibility on DWI at 5 weeks, may predict outcome of chemoradiotherapy
Radiation doses in ventriculoperitoneal shunt catheter imaging - Comparing traditional plain radiography with computed tomography and photon counting computed tomography.
No full textINTRODUCTION: Hydrocephalus is a common condition with enlarged ventricles in the brain. It is often surgically treated with a ventriculoperitoneal shunt system. These patients require regular radiological controls, which exposes them to a cumulative dose of ionizing radiation. The aim with this study was to identify CT protocols that provide diagnostically adequate image quality with equal or lower radiation dose, compared with traditional plain radiography. METHODS: Four anthropomorphic phantoms representing pediatric patients of ages 1, 5 and 10, and an adult, were imaged with a series of CT protocols on three different scanners (including one photon counting) to determine a protocol that would offer the lowest radiation dose with adequate image quality. The image quality was visually assessed and graded by two radiologists. For comparison, a retrospective study was conducted on patients who had undergone a shunt series with plain radiography from April 2021 to December 2023. RESULTS: The mean effective dose for all the 137 patients imaged with plain radiography was 2.35 mSv, ranging from 0.14 to 3.73 mSv. The mean effective dose increased with age. For all four phantoms, the study identified at least one CT protocol that provided a lower effective dose than the mean dose from plain radiography in the respective age group, as well as one minimal dose protocol per patient group. As expected, CT examinations had significantly shorter time durations (approximately 10 s vs 14.9 min for adults). CONCLUSION: This study showed that various low-dose CT protocols, with or without photon counting technology, can be used for imaging ventriculoperitoneal shunt catheters, with comparable or lower effective dose compared with plain radiography. IMPLICATIONS FOR PRACTICE: A transition from plain radiography to CT offers several benefits, such as decreased discomfort for the patient, shorter examination time, richer imaging data, and decreased radiation dose
AdAPT : Advertisement detector adaptation under newspaper domain shift with null-based pseudo-labeling
No full textDetecting advertisements in digitized newspapers is a key step in large-scale media analytics and digital archiving. However, variations in layout, typography, and advertisement design across publishers and time periods cause significant domain shifts that reduce the generalization ability of supervised detectors. This paper presents AdAPT, a confidence-guided pseudo-labeling pipeline for unsupervised domain adaptation in advertisement detection. The proposed method leverages both advertisement-free (Null) and advertisement-containing pages from unlabeled target domains to generate reliable pseudo-labels. By retraining a YOLO-based detector using labeled source data combined with filtered pseudo-labeled target samples, AdAPT achieves robust adaptation without requiring manual annotation. Experiments conducted on two unseen newspapers (Adresseavisen and iTromsø) demonstrate that Null-based pseudo-labeling provides the most stable and accurate adaptation, yielding up to 38% error reduction compared to the baseline. The results highlight AdAPT as a simple, scalable, and annotation-efficient solution for maintaining high-performance advertisement detection across diverse newspaper collections.CC BY 4.0Corresponding author: Faeze Zakaryapour SayyadReceived 16 October 2025, Revised 21 November 2025, Accepted 30 November 2025, Available online 1 December 2025, Version of Record 3 December 2025.Declaration of competing interestThe authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Faeze Zakaryapour Sayyad reports financial support was provided by Mid Sweden University. Faeze Zakaryapour Sayyad reports a relationship with Knowledge Foundation (kks.se) within the Industrial graduate school Smart Industry Sweden, Media Research company that includes: employment and funding grants. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.AcknowledgmentThis work was supported in part by The Knowledge Foundation(kks.se) within the Industrial graduate school Smart Industry Sweden and Media Research AB. The authors would also like to thank Oscar Berg for his valuable comments on this work.</p
Modeling and Simulating Cyberattacks with Dynamic Graphs : With applications to cloud security assessments
No full textThis dissertation presents a formalism for exploring two fundamental, yet underrepresented, cyberattack dynamics. Namely, how adversary actions drive the emergence of cyberattacks and how adversaries manipulate dynamic system structures, such as by creating and destroying objects. The formalism in question is encapsulated in the Dynamic Meta Attack Language (DynaMAL), a meta-level formalism for modeling and simulating cyberattacks with dynamic graphs. DynaMAL has been designed and developed in accordance with the design science research framework across four studies. The first study introduces an attack graph construction language for assessing cloud architectures and identifies the central problem of representing attacks in which adversaries manipulate dynamic system structures. The second study is a systematic literature review of cyberattack simulations that identifies key simulation concepts used in later stages of the design process. Building on the two initial studies, the third study establishes the cyberattack modeling foundations of DynaMAL, comprising a dynamic graph system, a multi-layered graph model, a lazy graph generation strategy, and the DynaMAL grammar. Finally, the fourth study develops the corresponding discrete-event simulation process for DynaMAL. The resulting capabilities are evaluated through a first simulation experiment that uses three cloud penetration testing scenarios that rely on dynamically creating and destroying resources. The scenarios are then solved automatically with near-optimal results by combining two search and optimization algorithms.I den här avhandlingen presenteras en formalism för att utforska två fundamentala men underrepresenterade cyberattackdynamiker. Dessa är hur antagonisters handlingar driver fram cyberattacker och hur antagonister manipulerar dynamiska systemstrukturer, till exempel genom att skapa och förstöra resurser. Formalismen i fråga är inkapslad i ett Dynamic Meta Attack Language (DynaMAL), en formalism på metanivå för att modellera och simulera cyberattacker med dynamiska grafer. DynaMAL:s design och utveckling fortlöper genom fyra studier utförda i enlighet med designforskningsramverket. Den första studien bidrar med ett attackgrafkonstruktionsspråk för att utvärdera molnarkitekturer, vilket utvecklar problematiken med att representera när antagonister manipulerar dynamiska systemstrukturer. Den andra studien är en systematisk litteraturstudie som granskar cyberattacksimuleringsforskning och uppdagar flertalet nyckelkoncept som understödjer de senare designaktiviterna. I den påföljande tredje studien etableras ett fundament för cyberattackmodellering innefattandes ett dynamiskt grafsystem, en lagerbaserad grafmodell, en lat grafgenereringsstrategi och DynaMAL-grammatiken. Den fjärde studien färdigställer DynaMAL-formalismen genom att implementera en motsvarande diskret händelsestyrd simuleringsprocess. De resulterande förmågorna utvärderas via ett första simuleringsexperiment, varvid tre molnpenetrationstestningsscenarion som krävde att resurser dynamiskt skapades eller förstördes används. Scenariona löses sedan automatiskt med nära inpå optimala resultat genom att kombinera två sök- och optimeringsalgoritmer.QC 20251219</p
Economic Evaluation of a Problem-Solving Intervention With Workplace Involvement Among Employees With Common Mental Disorder in Swedish Primary Care: Results From a Cluster-Randomized Controlled Trial
No full textObjectives The aim of this study was to evaluate the cost-effectiveness of a problem-solving intervention with workplace involvement (PSI-WPI) compared with care as usual (CAU) among employees on sick leave due to common mental disorders in Swedish primary healthcare centers. Methods Employees aged 18 to 59 years on sick leave for common mental disorders (n = 197) were included in a controlled cluster-randomized trial by coordinators (n = 19) recruited at primary care centers in Region Västra Götaland, Sweden. The study was conducted between February 2018 and August 2021, with 18 months of follow-up per participant. The economic evaluation included a cost-effectiveness analysis comparing changes in sick leave with direct costs from a healthcare perspective, calculated from register data, and intervention costs; a cost-utility analysis based on EQ-5D questionnaires and a societal perspective included indirect costs calculated from registered sick leave. Sensitivity analyses explored robustness to alternative missingness assumptions. Results The PSI-WPI resulted in more sickness absence (average 40 extra days; 95% confidence interval, 3-77 days) compared with CAU and higher healthcare costs (SEK 21 650, SEK 4962-48 262) over 18 months. At 12 months, the cost of care was SEK 23 734 (SEK 537-46 931) higher in the PSI-WPI group. The difference in quality-adjusted life-years between the groups was negligible. The sensitivity analysis indicated robust results, and diagnoses not targeted by the study were important cost drivers. Conclusions The PSI-WPI was not cost-effective for employees on sick leave due to common mental disorders compared with CAU only
Balancing grazing and biodiversity : arthropod responses to modern cattle farming practices
No full textRuminant production exerts severe pressure on ecosystems through land use change for pasture and fodder production, contributing to biodiversity loss, disruption of natural biogeochemical fluxes, and climate change. Whereas ruminant production can support biodiversity that has co-evolved with grasslands and grazing animals, the values of temporary grasslands are poorly understood. In this study, we assessed the effects of grazing regimes practised on modern cattle farms, including no grazing, on the abundance, biomass, and taxonomic richness of aerial and ground-dwelling arthropods. We assessed the potential value of organic management compared to grazing on conventional farms, and the role of vegetation structure on the pastures. We sampled arthropods in temporary pastures and silage grasslands, spring cereal fields, and in farmyards on 43 dairy and suckler cow farms in Finland. We show that grazing benefits the richness of ground-dwelling arthropods in fields, and the benefits were most evident at extensive levels of grazing at the farm scale. Grazing had no significant benefits for the biomass of ground-dwelling arthropods or relative abundance of aerial arthropods over field vegetation. Grazed rotational grasslands had similar levels of arthropods as mown grasslands or cereal crops, except for a higher richness of ground-dwelling arthropods. Taxonomic richness of ground-dwelling arthropods was higher on organic farms than conventional, but only at low grazing intensities. Although our study suggests several ways in which livestock farmers can maintain and increase arthropod populations on their farms, these may be associated with some reduction in production output on modern farms oriented towards high yields
Can Individuals with Visual Field Loss Drive Safely?
No full textIn Sweden, individuals with detected visual field loss (VFL) will have their driver’s license withdrawn based on perimetry results. In a previous study, a simulator-based method was used to test VFL individuals driving performance. Over 200 VFL individuals passed the simulator test and regained their driver’s licenses. Method: Seventy of the VFL individuals who had their driver’s license withdrawn due to VFL but then regained it after passing the simulator test and still had a valid driver’s license in February 2022 took part in a regular on-road driving test study. In addition, one age matched, and one younger control group (both groups matched on driving experience as well as area of living) also participated in this on-road study. Traffic inspectors, blind to group affiliation assessed the participants in cars provided by the exam office. Results: Just over 67% of the VFL participants passed the on-road test while almost 66% of the age- matched and just over 81% of the young controls passed the test. No statistical differences exist between the three groups. Discussion: The process used in Sweden for withdrawing driver’s licenses due to VFL seems to be unfair as all results indicate that participants with a detected VFL passed the on-road driving test to the same extent as did their matched controls. Second, a comparative study is needed to clarify if a simulator-based method or on-road testing is to prefer. Conclusion: Perimetry alone cannot predict driving performance on a driving test in a simulator nor on an on-road driving test assessed by traffic inspectors.
Lack of increase in mercury contamination in coastal Western Australia since European settlement
No full textCurrent knowledge of long-term mercury (Hg) deposition is predominantly based on studies from the Northern Hemisphere, leading to a geographical bias in the comprehension of the global Hg cycle. Aiming to contribute to fill this knowledge gap, our study presents a high-resolution Hg record of a seagrass Posidonia australis sedimentary archive encompassing the last 3300 years in the Waychinicup estuary (Western Australia, WA). This setting is an ideal site for studying the natural Hg cycle, as it is located in the southwest of the state, outside the prevailing wind patterns that transport emissions from major Hg sources. Our results show that Hg concentrations fluctuated from ∼1300 BCE to 100 CE with a shift in the paleorecord around 350 BCE, which could potentially be associated with an intensified El Niño Southern Oscillation period. From around 100 until ∼1880 CE, the Hg concentration remained relatively constant (∼2 μg kg−1) with an increase up to 8 μg kg−1 from 1880 CE until present. Although Hg accumulation doubled since European settlement in WA (from 2.4 to 4.8 μg m−2 yr−1), such an increase can be explained by enhanced organic carbon accumulation, rather than changes in external Hg fluxes. Therefore, our study showcases the importance of considering biogeochemical processes when reconstructing long-term Hg accumulation based on sedimentary archives. Furthermore, the results demonstrate the key role of seagrass meadows as natural paleoarchives of environmental contamination, providing valuable insights into human impacts on coastal areas and to establish pre-anthropogenic baseline metal concentrations
"I care about transport sustainability, but i have children": Open-text surveys highlight the concerns of families with children
No full textThe importance of providing access to quality public transport has been discussed in numerous literature and reports. Despite growing recognition of the need for inclusive public transport, the specific mobility needs of children and their caregivers remain largely overlooked in transport planning and evaluation. Conventional assessments—which rely on structured, expert-driven criteria such as accessibility, punctuality, and safety— often fail to capture the nuanced capabilities and unequal access experienced by underrepresented groups, such as families with children. This study addresses this gap by adopting an inductive approach to analyze open-text responses from survey data collected between 2022 and 2023 by the Swedish Public Transport Association. Employing sentiment and content analysis, we investigated how the survey respondents address children-related accessibility challenges and concerns about traveling by public transport while accompanying children. Approximately 15 % of the survey respondents answered the open-text questions, with around 3 % (415 individuals in 2022 and 588 in 2023) specifically mentioning the words “child” or “children.” Reviewing the responses, we identified four key concerns that constrain the capabilities of children and their caregivers: (1) time-management pressures, (2) affordability and value concerns, (3) safety concerns, and (4) comfort and convenience limitations. Through the lenses of transport justice and capability theory, we argue that capability deprivation could reinforce car dependency or reduce mobility and social participation opportunities for families with children. The results underscore the need to integrate child- and caregiver-specific needs into public transport planning and design. Furthermore, this study highlights the value of unstructured public feedback in revealing unmet mobility demands and nuanced quality expectations, which are critical for ensuring equitable access to sustainable transport for all citizens