Development, verification, and maintenance of computational software in geodynamics

Research on dynamical processes within the Earth and planets increasingly relies upon sophisticated, large-scale computational models. Improved understanding of fundamental physical processes such as mantle convection and the geodynamo, magma dynamics, crustal and lithospheric deformation, earthquake nucleation, and seismic wave propagation, are heavily dependent upon better numerical modeling. Surprisingly, the rate-limiting factor for progress in these areas is not just computing hardware, as was once the case. Rather, advances in software are not keeping pace with the recent improvements in hardware. Modeling tools in geophysics are usually developed and maintained by individual scientists, or by small groups. But it is difficult for any individual, or even a small group, to keep up with sweeping advances in computing hardware, parallel processing software, and numerical modeling methodology

Uncertainty propagation through a point model for steady-state two-phase pipe flow

Uncertainty propagation is used to quantify the uncertainty in model predictions in the presence of uncertain input variables. In this study, we analyze a steady-state point-model for two-phase gas-liquid flow. We present prediction intervals for holdup and pressure drop that are obtained from knowledge of the measurement error in the variables provided to the model. The analysis also uncovers which variables the predictions are most sensitive to. Sensitivity indices and prediction intervals are calculated by two different methods, Monte Carlo and polynomial chaos. The methods give similar prediction intervals, and they agree that the predictions are most sensitive to the pipe diameter and the liquid viscosity. However, the Monte Carlo simulations require fewer model evaluations and less computational time. The model predictions are also compared to experiments while accounting for uncertainty, and the holdup predictions are accurate, but there is bias in the pressure drop estimatespublishedVersio

Community Seismic Network

The article describes the design of the Community Seismic Network, which is a dense open seismic network based on low cost sensors. The inputs are from sensors hosted by volunteers from the community by direct connection to their personal computers, or through sensors built into mobile devices. The server is cloud-based for robustness and to dynamically handle the load of impulsive earthquake events. The main product of the network is a map of peak acceleration, delivered within seconds of the ground shaking. The lateral variations in the level of shaking will be valuable to first responders, and the waveform information from a dense network will allow detailed mapping of the rupture process. Sensors in buildings may be useful for monitoring the state-of-health of the structure after major shaking

Social and life skills in adolescents who have self-harmed: analysis of survey responses from a national sample of adolescents in Norway

publishedVersio

Extensive spontaneous plasticity of corticospinal projections after primate spinal cord injury.

Although axonal regeneration after CNS injury is limited, partial injury is frequently accompanied by extensive functional recovery. To investigate mechanisms underlying spontaneous recovery after incomplete spinal cord injury, we administered C7 spinal cord hemisections to adult rhesus monkeys and analyzed behavioral, electrophysiological and anatomical adaptations. We found marked spontaneous plasticity of corticospinal projections, with reconstitution of fully 60% of pre-lesion axon density arising from sprouting of spinal cord midline-crossing axons. This extensive anatomical recovery was associated with improvement in coordinated muscle recruitment, hand function and locomotion. These findings identify what may be the most extensive natural recovery of mammalian axonal projections after nervous system injury observed to date, highlighting an important role for primate models in translational disease research

Epidemiological Studies Among Royal Norwegian Navy Servicemen : Cohort Establishment, Cancer Incidence and Cause-Specific Mortality

The thesis covers the establishment and quality controls of two cohorts of civilian and military personnel serving in the Royal Norwegian Navy (RNoN) after January 1, 1950, and two studies among male members of the military cohort. For the civilian cohort, the criterion for inclusion was all civilians who have served at any time during 1950–2005 in the Navy, while the military cohort was limited to officers and enlisted personnel. All branches of the Navy were covered, hereunder the Fleet, the Coast Guard and the Coastal Artillery. By 1950, the Norwegian Fleet was either destroyed during the Second World War (WWII) or out-dated. The rebuilding of the Navy was yet to begin, and Norway had just become a member of the North Atlantic Treaty Organisation (NATO) at the Treaty foundation in 1949. With its border with the Soviet Union in the north Norway became of strategic importance, and the Cold War shaped the design of the Norwegian Defence. The present work started in 2002 with establishment of the cohorts. The registration work resulted in a military cohort of 29 056 persons (2.5% women) with an average of 6.2 years service in the Navy. The cohort of 8 378 civilians (39% women) had an average of 11 years in the Navy. Both cohorts were regarded as virtually complete. The first cohort study dealt with asbestos related cancers among Navy vessels crews. Asbestos has been commonly used in shipbuilding for heat and sound insulation, and for fireproofing. Until 1987, asbestos aboard the Navy vessels potentially caused exposure to 11 500 crew members. Engine room crews were considered to experience higher exposure intensity than other crews aboard. Asbestos is the only environmental factor known to cause malignant mesothelioma, and an elevated incidence of this disease served as an indicator of asbestos exposure. The incidence of other potentially asbestos related cancers (lung, laryngeal, pharyngeal, stomach and colorectal cancers) was evaluated according to duty station and mesothelioma incidence. Elevated incidence of mesothelioma was found among engine room crews only, and the time from first exposure to date of diagnosis ranged from 28 to 48 years (median 41). The mesothelioma incidence offered no consistent explanation to the variation in incidence of other potentially asbestos-related cancers. The second cohort study examined the cause-specific mortality and cancer incidence compared to the national rates. Internal comparisons between vessel crews and land-based personnel were performed. A military career implies adaptation to a rigid disciplinary system, handling of weaponry, and a life at remote locations causing separation from family members. In foreign navies, a higher than average alcohol consumption with a negative impact on occupational efficiency and adverse health outcome, has been reported. Special attention was thus given towards deaths from violent causes, alcohol related diseases (mental and behavioural disorders due to use of alcohol, liver cirrhosis) and incidence of alcohol-related cancers (mouth, pharynx, larynx, oesophagus and liver cancer). For the cohort as a whole, the overall mortality was 16% lower than in the general Norwegian male population. The physical and psychological screenings for military service and the demand for “keeping up” during service imply that the Navy personnel were highly selected and expected to be healthier than the general population. This phenomenon has been termed “healthy soldier effect”. Overall cancer incidence was 6% higher, mostly due to excess prostate cancer and malignant melanoma and non-melanoma skin cancers. Death from violent causes (accidents and suicide) was 36% lower than expected. Both overall mortality and cancer were higher among sailors than among land-based personnel. No increased risk of alcohol related cancers or mortality was found for the cohort as a whole, but a higher risk was found among those serving aboard the vessels than for land based personnel.  Epidemiologiske studier blant offiserer og vervet personell i Sjøforsvaret. Kohortetablering, kreftforekomst og årsaksspesifikk dødelighet Avhandlingen omhandler etablering og kvalitetskontroller av kohorter (studiegrupper) bestående av sivilt og militært personell som har tjenestegjort i Sjøforsvaret (Marinen, Kystvakta og Kystartilleriet) etter 1950, samt to epidemiologiske studier blant mannlige militære. Tidsperioden karakteriseres av gjenoppbygging etter den andre verdenskrig, hvor Sjøforsvaret tilpasses ”den kalde krigen” og designes for invasjonsforsvar i kyst-farvann, og Sovjetunionens fall i 1991 med påfølgende omorganisering og nedbygging. Arbeidet startet i 2002 med etablering av kohorter. Kilde til personopplysninger var Forsvarets Personelldatabase og rulleblader på papir. Inkludert i den sivile kohorten var alle sivilt ansatte, mens den militære kohorten ble begrenset til offiserer og vervete. Registreringsarbeidet resulterte i en militær kohort bestående av 29 056 personer, hvorav 2,5% kvinner, med gjennomsnitt tjenestetid i Sjøforsvaret på 6 år. Den sivile kohorten bestod av 8341 personer (39% kvinner) med 11 års tjeneste i snitt. Kohortene ble vurdert å være nær komplette. Observerte antall krefttilfeller og dødsfall blant Sjøforsvarspersonellet ble sammenlignet med tilsvarende tall for den mannlige norske befolkning. Det ble også foretatt interne sammenligninger mellom ulike avdelinger i Sjøforsvaret. Den første kohortstudien omhandlet asbestrelatert kreft. Asbest har vært brukt i skipsbygging som varme- og støyisolasjon og som brannsikring, og ble fjernet ved utskifting og overhaling av fartøyene i løpet av 1980-tallet. Rundt 11 500 besetningsmedlemmer kan ha vært eksponerte. Asbest er den eneste kjente miljøfaktor som kan forårsake mesoteliom (brysthinnekreft), og andre asbestrelaterte kreftformer (kreft i lunge, svelg, strupe, mage, og i tykk- og endetarm) ble evaluert i lys av tjenestested og forekomst av mesoteliom. Økt risiko for mesoteliom ble kun funnet blant maskinromsbesetninger. Den andre kohortstudien dreide seg om kreft og dødsårsaker. Militær karriere betyr tilpasning til et rigid disiplinært system, håndtering av våpen og potensielt farlig maskineri, samt tjeneste på fjerne steder, atskilt fra familie. Et stort potensiale for ulykker, samt rapporter om høyt alkoholforbruk i utenlandske mariner, medførte fokus på voldsomme dødsfall samt dødsfall grunnet alkoholrelaterte sykdommer som skrumplever og alkoholpsykoser, og forekomst av alkoholrelatert kreft. For kohorten under ett var dødeligheten 16% lavere enn i den generelle norske mannlige befolkning. Dette kan forklares med seleksjoner på fysisk og mental helse ved opptak til militærtjeneste (sesjon) og befalsutdanning, samt regelmessige fysiske tester og helsekontroller under tjenesten. Kreftforekomsten var 6% forhøyet, først og fremst grunnet økt forekomst av prostatakreft og hudkreft. Voldsomme dødsfall (ulykker, selvmord) var 36% lavere enn forventet. Generelt var dødelighet og kreftforekomst høyere blant fartøybesetninger enn landbasert personell. Ingen økt risiko for alkoholbetinget dødsfall eller kreft ble observert for kohorten under ett, men høyere risiko ble funnet for fartøybesetningene sammenliknet med landpersonell