Constrained information flows in temporal networks reveal intermittent communities

Many real-world networks represent dynamic systems with interactions that change over time, often in uncoordinated ways and at irregular intervals. For example, university students connect in intermittent groups that repeatedly form and dissolve based on multiple factors, including their lectures, interests, and friends. Such dynamic systems can be represented as multilayer networks where each layer represents a snapshot of the temporal network. In this representation, it is crucial that the links between layers accurately capture real dependencies between those layers. Often, however, these dependencies are unknown. Therefore, current methods connect layers based on simplistic assumptions that do not capture node-level layer dependencies. For example, connecting every node to itself in other layers with the same weight can wipe out dependencies between intermittent groups, making it difficult or even impossible to identify them. In this paper, we present a principled approach to estimating node-level layer dependencies based on the network structure within each layer. We implement our node-level coupling method in the community detection framework Infomap and demonstrate its performance compared to current methods on synthetic and real temporal networks. We show that our approach more effectively constrains information inside multilayer communities so that Infomap can better recover planted groups in multilayer benchmark networks that represent multiple modes with different groups and better identify intermittent communities in real temporal contact networks. These results suggest that node-level layer coupling can improve the modeling of information spreading in temporal networks and better capture intermittent community structure.Comment: 10 pages, 10 figures, published in PR

Relevant vs non-relevant subspecialist for patients hospitalised in internal medicine at a local hospital: which is better? A retrospective cohort study

Background: Studies of the treatment of patients in-hospital with a specifc diagnosis show that physicians with a subspecialisation relevant to this diagnosis can provide a better quality of care. However, studies including patients with a range of diagnoses show a more negligible efect of being attended by a relevant subspecialist. This project aimed to study a more extensive set of patients and diagnoses in an environment where the subspecialist present could be controlled. Thus, this study investigated whether being attended by a physician with a subspeciality relevant to the patient’s primary diagnosis was prospectively associated with readmission, in-hospital mortality, or length of stay compared to a physician with a subspeciality not relevant to the patient’s primary diagnosis. Methods: We have conducted a retrospective register-based study of 11,059 hospital admissions across 9 years at a local hospital in south-eastern Norway, where it was possible to identify the physician attending the patients at the beginning of the stay. The outcomes studied were emergency readmissions to the same ward within 30days, any in hospital mortality and the total length of stay. The patients admitted were matched with the consultant(s) responsible for their treatment. Then, the admissions were divided into two groups according to their primary diagnosis. Was their diagnosis within the subspeciality of the attending consultant (relevant subspecialist) or not (non-relevant subspecialist). The two groups were then compared using bivariable and multivariable models adjusted for patient characteristics, comorbidities, diagnostic group and physician sex. Results: A relevant subspecialist was present during the frst 3 days in 8058 (73%) of the 11,059 patient cases. Patients attended to by a relevant subspecialist had an odds ratio (OR) of 0.91 (95% confdence interval 0.76 to 1.09) for being readmitted and 0.71 (0.48 to 1.04) for dying in the hospital and had a length of stay that was 0.18 (−0.07 to 0.42) days longer than for those attended to by a non-relevant subspecialist. Conclusions: This study found that patients attended by a relevant subspecialist did not have a signifcantly diferent outcome to those attended by a non-relevant subspecialist. Keywords: Subspecialisation, Internal medicine, Treatment outcome, Readmissions, In-hospital mortality, Length of staypublishedVersio

Rhythm of relationships in a social fish over the course of a full year in the wild

Abstract Background Animals are expected to adjust their social behaviour to cope with challenges in their environment. Therefore, for fish populations in temperate regions with seasonal and daily environmental oscillations, characteristic rhythms of social relationships should be pronounced. To date, most research concerning fish social networks and biorhythms has occurred in artificial laboratory environments or over confined temporal scales of days to weeks. Little is known about the social networks of wild, freely roaming fish, including how seasonal and diurnal rhythms modulate social networks over the course of a full year. The advent of high-resolution acoustic telemetry enables us to quantify detailed social interactions in the wild over time-scales sufficient to examine seasonal rhythms at whole-ecosystems scales. Our objective was to explore the rhythms of social interactions in a social fish population at various time-scales over one full year in the wild by examining high-resolution snapshots of a dynamic social network. Methods To that end, we tracked the behaviour of 36 adult common carp, Cyprinus carpio, in a 25 ha lake and constructed temporal social networks among individuals across various time-scales, where social interactions were defined by proximity. We compared the network structure to a temporally shuffled null model to examine the importance of social attraction, and checked for persistent characteristic groups over time. Results The clustering within the carp social network tended to be more pronounced during daytime than nighttime throughout the year. Social attraction, particularly during daytime, was a key driver for interactions. Shoaling behavior substantially increased during daytime in the wintertime, whereas in summer carp interacted less frequently, but the interaction duration increased. Therefore, smaller, characteristic groups were more common in the summer months and during nighttime, where the social memory of carp lasted up to two weeks. Conclusions We conclude that social relationships of carp change diurnally and seasonally. These patterns were likely driven by predator avoidance, seasonal shifts in lake temperature, visibility, forage availability and the presence of anoxic zones. The techniques we employed can be applied generally to high-resolution biotelemetry data to reveal social structures across other fish species at ecologically realistic scales

Vurdering av filleristing av barn i straffesaker for norske domstoler

Dette er en flerfaglig gjennomgang av samtlige norske straffesaker funnet på Lovdata fra 2004 fram til 2015 om «filleristing». Hver sak er gjennomgått av forfatterne; to jurister og tre medisinske eksperter på hodeskader hos barn. Materialet har bestått av straffesaksdokumentene, inkludert sakkyndige rapporter og aktuelle pasientjournaler med billeddiagnostikk av de samme barna. Rettssakene presenteres ut fra dommene, og i de aktuelle sakene er rettens vurderinger i mange saker knyttet opp mot de rettssakkyndiges vurderinger. Parallelt har de medisinske forfatterne etterprøvd hvorvidt de sakkyndiges vurderinger står seg ut fra dagens kunnskap om slike skadebilder. Særlig vekt er lagt på muligheten for at skadebildet ikke er påført ved foreldres eller andres voldsbruk, men av medisinske tilstander hos barnet selv. Det kan synes som om det er få fellende straffedommer som utelukkende er basert på sakkyndighetsvurderinger vedrørende filleristing. I flere andre saker synes det å foreligge tvil når det gjelder skadeårsak og skadepåføring. I tillegg presenteres enkelte barnevernssaker med vekt på beviskravet ved filleristing sammenliknet med straffesakene, men her uten å ha foretatt nye medisinske vurderinger