194 research outputs found
Verona validation of the DAAE score, a tool for estimating risk of clinical disease progression in people with multiple sclerosis
No full textBackground: The DAAE Score is a tool for estimating patient risk of disease progression. We aimed to validate this tool externally. Methods: Data was collected from a clinical cohort treated at the MS Center of Verona. We appraised binary predictions in case-control balanced data using synthetic-minority-oversampling techniques. Results: Included patients (n = 218) had a mean(SD) age and disease duration of 36.8(11.0) and 6.5(6.6). Over 5.2(1.2) years, 53(24.3 %) patients converted to secondary progressive MS. Validation analyses revealed an AUROC=0.948[95 %CI=0.918-0.978], brier-score=1.09, prediction accuracy=89.4 %(95 %CI=85.1 %-94.1 %), sensitivity=0.76(95 %CI=0.69-0.84), and specificity=0.94(95 %CI=0.90-0.99). Conclusion: Within MS Center of Verona, the DAAE Score performs well on external validation
Informing Design for Sustainable Behaviour
No full textPhD i produktdesignPhD in Industrial Design Engineerin
Clinical risk stratification: Development and validation of the DAAE score, a tool for estimating patient risk of transition to secondary progressive multiple sclerosis
No full textBackground: Because secondary progressive multiple sclerosis (SPMS) is associated with worse prognosis, early predictive tools are needed. We aimed to use systematic literature review and advanced methods to create and validate a clinical tool for estimating individual patient risk of transition to SPMS over five years. Methods: Data from the Jacobs Multiple Sclerosis Center (JMSC) and the Multiple Sclerosis Center Amsterdam (MSCA) was collected between 1994 and 2022. Participants were relapsing-remitting adult patients at initial evaluation. We created the tool in four stages: (1) identification of candidate predictors from systematic literature review, (2) ordinal cutoff determination, (3) feature selection, (4) feature weighting. Results: Patients in the development/internal-validation/external-validation datasets respectively (n = 787/n = 522/n = 877) had a median age of 44.1/42.4/36.6 and disease duration of 7.7/6.2/4.4 years. From these, 12.6 %/10.2 %/15.4 % converted to SPMS (median=4.9/5.2/5.0 years). The DAAE Score was named from included predictors: Disease duration, Age at disease onset, Age, EDSS. It ranges from 0 to 12 points, with risk groups of very-low=0–2, low=3–7, medium=8–9, and high≥10. Risk of transition to SPMS increased proportionally across these groups in development (2.7 %/7.4 %/18.8 %/40.2 %), internal-validation (2.9 %/6.8 %/26.8 %/36.5 %), and external-validation (7.5 %/9.6 %/22.4 %/37.5 %). Conclusion: The DAAE Score estimates individual patient risk of transition to SPMS consistently across datasets internationally using clinically-accessible data. With further validation, this tool could be used for clinical risk estimation
Exchange of water masses between the southern Weddell Sea continental shelf and the deep ocean
No full textThe exchange of water masses between the shallow Weddell Sea continental shelf and the deep ocean is of climatic importance. Firstly, on-shelf transport of warm oceanic water masses, contributes to basal melting of ice shelves, which affects the stability of the Antarctic Ice Sheet. Secondly, export of denseWeddell Sea shelf water, contributes to production of Antarctic Bottom Water (AABW), which feeds into the lower limb of the global thermohaline circulation. This thesis considers processes related to both on-shelf heat transport, and to export of dense shelf water. Based on a combination of idealized numerical model experiments and observations of hydrography and current at various locations in the southern Weddell Sea, the thesis discusses pathways and variability of the oceanic circulation along the continental slope, on the continental shelf and inside the Filchner Trough (FT), a deep trough across the continental shelf. The response to wind forcing is assessed, along with mechanisms contributing to mixing and transformation of water masses. The Antarctic Slope Front (ASF) protects the Weddell Sea continental shelf from the salineWarm DeepWater (WDW) offshore. Most of the on-shore transport occurs in the summer season, when the thermocline is shoaling at the shelf break, and through the FT, where the sill depth is 200 m below the shelf depth. However, on-shelf transport of warm water may also occur when dense shelf water is present on the shelf. An isopycnal connection between the dense shelf water and the WDW offshore creates a pathway for WDWto access the shelf without doing work against the buoyancy forces. The southward transport of heat into the FT is sensitive to the slope current properties, and to the characteristics of the dense shelf water. The slope current is associated with the ASF, and flows westward along the continental slope. The core of the slope current is found to migrate shoreward onto shallower isobaths under strong wind forcing, leading to different inflow regimes in the FT. In the weak wind regime, the slope current core is located over deep isobaths, and does not interact with the FT topography. In this regime, the southward heat transport into the FT is dominated by eddies, and is sensitive to dense shelf water properties. In the strong wind regime, the slope current is topographically steered southward into the Filchner sill region. However, potential vorticity constraints at the sill edge force the slope current to turn and exit the Filchner sill, without reaching the deeper part of the trough. The recirculating slope current efficiently advects eddies out of the Filchner sill area, and limits the southward heat transport. A recirculation of the slope current across the Filchner sill could influence the export of dense Ice Shelf Water (ISW) from the FT. The slope current is mainly wind-driven, and responds to monthly scale variability in the along-slope wind stress. Here, it is shown that the variability of the ISW overflow velocity is also connected to the upstream wind stress, which could result from interaction between the ISW overflow and the recirculating slope current. New insight is gained regarding the ISW pathway from the Filchner Ice Shelf (FIS) front toward the continental slope. The ISW is flowing northward as a mid-depth jet along the eastern side of the FT. An eastward turning of the ISW across the FIS front could be related to potential vorticity constraints associated with the large increase in water column depth at the FIS front. The dense ISW overflows the Filchner sill and continues westward along the continental slope as a bottom intensified plume. The plume thickness fluctuates strongly on time scales of a few days. High shear and mixing is observed during the early stage of a thick plume event, and indicate efficient entrainment of WDW, which is essential for production of AABW. The efficient mixing is, at least partly, related to topographic vorticity waves. In summary this thesis discusses key elements of the current circulation and its variability in the southern Weddell Sea. The thesis demonstrates the inter-connection between the cold water masses on the continental shelf and the warmer off-shelf water masses. Today, the ASF is an important barrier which protects the Weddell Sea continental shelf from the warm water off-shore. However, the stability of the ASF is vulnerable to climate change, and is not well resolved in global climate models. This study highlights the need for improved understanding of the processes related to the slope front system, and the importance of the exchange and interaction between water masses in the Filchner Trough
Katalysator eller kontrollør? Samspillet mellom synlig ledelse og kontinuerlig forbedring i lean produksjon
No full textLean er et populært organisasjonsdesign i vår samtid og i dag snakker de aller fleste industrikretser om lean (Skorstad, 2021). Ved å innføre en rekke grep, for eksempel standardisering, synlig ledelse og kontinuerlig forbedring, lover organisasjonsformen forbedret produktivitet og kvalitet (Ingvaldsen, Ringen og Rolfsen, 2014). I møtet mellom synlig ledelse og kontinuerlig forbedring oppstår imidlertid et tilsynelatende paradoks: På den ene siden passer ledere på at arbeidet foregår som det skal. Samtidig oppfordres ansatte til å drive forbedringsarbeid av prosessene. Ansatte blir altså både kontrollert, og oppfordret til å ta kontrollen selv. Samspillet mellom synlig ledelse og kontinuerlig forbedring danner dermed utgangspunkt for denne oppgaven, som har fått lite oppmerksomhet i forskningen som foreligger.
For å besvare forskningsspørsmålet har jeg gjennomført en casestudie hos det norske industriselskapet Hydro. Jeg har studert to avdelinger på to ulike aluminiumsverk som har implementert lean og anvender praksisene synlig ledelse og kontinuerlig forbedring. Metoder som feltarbeid, intervjuer og dokumentgjennomgang er brukt, i tillegg til at jeg har nyttiggjort meg av min egen erfaring fra bedriften som ferievikar, intern og forskningsassistent.
Funnene fra studien viser at synlig ledelse foregår på ulike måter som har ulike effekter på operatørdrevet kontinuerlig forbedring. Fysisk tilstedeværelse støtter operatørers aktive deltakelse i forbedringsarbeidet, men å være fysisk til stede er ikke tilstrekkelig i seg selv. Å demonstrere synlighet ved å følge opp arbeidsutførelse samt forbedringsforslag og -grupper er i større grad effektivt for å engasjere operatører i forbedringsarbeid. I caseorganisasjonen kommer denne oppfølgingen vanligvis til uttrykk gjennom uformelle former for synlig ledelse heller enn gjennom de planlagte strukturene.
Forskningen min bidrar til å utvide det vi vet om lean ledelse generelt, og relasjonen mellom synlig ledelse og kontinuerlig forbedring spesielt. Allerede er det godt etablert i litteraturen at ledelse er avgjørende for å lykkes med lean, noe min forskning underbygger. Jeg argumenterer for at synlig ledelse ikke nødvendigvis stikker kjepper i hjulene for operatørers engasjement i forbedringsarbeid. Ved å anvende elementer fra relasjonsorienterte lederstiler kan ledere tvert imot fungere som en katalysator for operatørdrevet kontinuerlig forbedring.
Referanser:
Ingvaldsen, J. A., Ringen, G. og Rolfsen, M. (2014) Lean på global vandring, i Rolfsen, M. (red.) Lean blir norsk: Lean i den norske samarbeidsmodellen. Bergen: Fagbokforlaget, s. 33-47.
Skorstad, E. J. (2021) Organisasjonsformer: Arbeidsvilkår og effektivitet. 3. utgave. Oslo: Gyldendal.Lean is a popular organizational design in the present times, and most industrial circles today talk about lean (Skorstad, 2021). By adopting a set of practices, for instance, standardization, visual leadership, and continuous improvement, lean makes promises about increased efficiency and profitability (Ingvaldsen, Ringen og Rolfsen, 2014). However, a paradox emerges when visual leadership and continuous improvement are combined. Managers inspect the work to ensure that it is in line with the defined procedures, all the while employees are encouraged to lead improvements of the same work processes. Thus, employees are both controlled and encouraged to take control themselves. This master’s thesis explores the relationship between visual leadership and continuous improvement, which has gotten little attention in the prior literature.
To answer my research question, I have conducted a case study at the Norwegian industrial company Hydro. I have studied two departments of two different aluminum factories. The departments have adopted lean, as well as visual leadership and continuous improvement as practices. Methods like fieldwork, interviews, and document review have been used. Also, my own experience within the company as a holiday substitute, intern, and research assistant has extended my understanding.
The findings from my study show that visual leadership is conducted in various ways with different effects on employee-driven continuous improvement. Physical presence supports active participation among employees, but merely being present is not sufficient. Demonstrating presence by following up on work performance, improvement suggestions, and improvement groups is more effective in encouraging employees to contribute to continuous improvement activities. In the case organization, such follow-ups usually happen in informal settings rather than through formal work systems.
My research contributes to the field of lean leadership, especially on the topics of visual leadership and continuous improvement. It is well-established in the prior literature that leadership is essential to succeed with lean, which is underpinned by my research. I argue that visual leadership does not necessarily inhibit employee-driven continuous improvement. If leaders adopt elements from relational-oriented leadership styles, leaders can be catalysts rather than obstructors of employee-driven continuous improvement.
References:
Ingvaldsen, J. A., Ringen, G. og Rolfsen, M. (2014) Lean på global vandring, i Rolfsen, M. (red.) Lean blir norsk: Lean i den norske samarbeidsmodellen. Bergen: Fagbokforlaget, s. 33-47.
Skorstad, E. J. (2021) Organisasjonsformer: Arbeidsvilkår og effektivitet. 3. utgave. Oslo: Gyldendal
Differentiated Food Taxes as a Tool in Health and Nutrition Policy
No full textThe purpose of the present study is to analyse the effects of using economic policy tools in nutrition policy, e.g. introduction of specific taxes on unhealthy food components or differentiated VAT on foods. The effects of such regulation instruments are demonstrated using Denmark as an illustrative case. A model concept combining econometric models of food consumption behaviour for different socio-demographic groups with a model for conversion between food consumption and nutrient intake is developed. The socio-demographic effects of four different tax or subsidy regulation schemes are investigated.obesity, food taxes, econometric model, socio-demographic differences, Agricultural and Food Policy, Food Consumption/Nutrition/Food Safety,
Målinger i sjøen ved Kårstø, 2008-2009 Datarapport
No full textRapporten oppsummerer målinger av strøm og temperatur/hydrografi i sjøen ved Kårstø i perioden juni 2008 – juni 2009. Feltprogrammet bestod av strømmåling på Falkeidflæet, logging av temperatur (og salinitet) i 70 m og 100 m dyp ved kjølevannsinntaket ved Haugsneset, samt supplerende vertikalprofiler for hydrografi ved Haugsneset og på Falkeidflæet. Rapporten presenterer måleresultatene, uten noen dyptgående diskusjon. Materialet er tilgjengelig i digital form for evt. seinere anvendelser.Gassnova SF, Porsgrunn v/ Laila Helgesen / Bjørn Bergese
Transkraniell likestrømsstimulering og Alzheimers sykdom: Forholdet mellom kognitiv prestasjon og vanndiffusjon i hvit substans
No full textFormålet med oppgaven var å undersøke effekten av anodal high definition (HD)-tDCS over venstre dorsolateral prefrontal cortex hos pasienter med Alzheimers sykdom. Utfallsmål var prestasjoner på tester for oppmerksomhet, utsatt hukommelse og på Repeatable Battery for the Assessment of Neuropsychological Status total indeksskåre. Diffusjons tensor avbildning ble også benyttet for mål på fraksjonell anisotropi (FA), gjennomsnittlig diffusjon (MD), aksonal diffusjon (AD) og radial diffusjon (RD) i fiberbanene venstre anterior thalamic radiation, venstre cingulum cingular bundle og forceps minor. Resultatene ga ikke indikasjon for at anodal HD-tDCS kan forbedre kognitiv prestasjon hos pasienter med Alzheimers sykdom. Det ble imidlertid observert en tendens til at deltakere med høyere FA og lavere MD, RD og AD viste en mer stabil kognitiv prestasjon i etterkant av tDCS behandlingen. Effekten var mest fremtredende for hukommelsesfunksjon
A four-month home-based tDCS study on patients with Alzheimer’s disease
No full textIn the present open-label study, our first aim was to study the tolerability and feasibility of long-term treatment with transcranial direct current stimulation (tDCS) and the second aim was to measure whether the treatment led to cognitive improvement. Participants with AD used a tDCS home-treatment kit inducing a low current (2 mA) via two scalp electrodes 30 minutes daily for 4 months. A total of 8 participants were recruited. The treatment technique was manageable for the participants and their spouses, and no troublesome side effects were reported. No significant effects of treatment were found after 4 months
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