BLI EN DEL AV GJENGEN; HVORDAN MOTIVASJONSFAKTORER KAN BIDRA TIL Å BEKJEMPE TURNOVER I HOTELLBRANSJEN.

Denne oppgaven er utarbeidet i samarbeid med et utvalg konferanse- og leisurehoteller i Oslo-området. Studiet er basert på strategier og modeller som i kontekst med vår problemstilling og våre hypoteser forsøker å belyse temaet turnover i hotellbransjen. Gruppen belyser spesifikt tematikken rundt hva som motiverer den enkelte hotellmedarbeider og hvordan hoteller jobber for å beholde kompetente medarbeidere. Oppgaven vektlegger bruk av motivasjons- og hygienefaktorer for å bekjempe den høye graden av turnover som går igjen i bransjen. Det er benyttet kvalitativ metode i gjennomføringen blant ledere på de respektive hotellavdelingene. Gruppen har valgt å benytte dybdeintervjuer for å samle inn data. Funnene fra undersøkelsen konstaterer at sosiale betingelser spiller en større rolle for de ansatte motivasjon enn tidligere antatt, og at det bør rettes et større fokus mot å sikre gode sosiale forhold på arbeidsplassen. Videre anbefales det å kontinuerlig arbeide med kompetanse- og karriereutvikling for å sikre at kompetente medarbeidere ikke slutter i sine stillinger. Det ble også oppdaget at deler av teorien kan være noe utdatert og at noen sentrale teorier om motivasjon kan ha behov for modifikasjoner

Survival of glioblastoma in relation to tumor location: a statistical tumor atlas of a population-based cohort

Purpose: Previous studies on the effect of tumor location on overall survival in glioblastoma have found conflicting results. Based on statistical maps, we sought to explore the effect of tumor location on overall survival in a population-based cohort of patients with glioblastoma and IDH wild-type astrocytoma WHO grade II–III with radiological necrosis. Methods: Patients were divided into three groups based on overall survival: 24 months. Statistical maps exploring differences in tumor location between these three groups were calculated from pre-treatment magnetic resonance imaging scans. Based on the results, multivariable Cox regression analyses were performed to explore the possible independent effect of centrally located tumors compared to known prognostic factors by use of distance from center of the third ventricle to contrast-enhancing tumor border in centimeters as a continuous variable. Results: A total of 215 patients were included in the statistical maps. Central tumor location (corpus callosum, basal ganglia) was associated with overall survival 24 months. Increased distance from center of the third ventricle to contrast-enhancing tumor border was a positive prognostic factor for survival in elderly patients, but less so in younger patients. Conclusions: Central tumor location was associated with worse prognosis. Distance from center of the third ventricle to contrast-enhancing tumor border may be a pragmatic prognostic factor in elderly patients.publishedVersio

Exposure to a Human Relevant Mixture of Persistent Organic Pollutants or to Perfluorooctane Sulfonic Acid Alone Dysregulates the Developing Cerebellum of Chicken Embryo

Acknowledgements This project has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement No. 722634 (http://protected.eu.com/). The authors gratefully acknowledge the Proteomics Core Facility of the University of Aberdeen for their support & assistance in this work. The sequencing service was provided by the Norwegian Sequencing Centre (www.sequencing.uio.no), a national technology platform hosted by the University of Oslo and supported by the "Functional Genomics" and "Infrastructure" programs of the Research Council of Norway and the South-eastern Regional Health Authorities.Peer reviewedPublisher PD

Preoperative Planning and Functional Neuronavigation : with Functional MRI and Diffusion Tensor Tractography in Patients with Brain Lesions

Blood-Oxygenation-Level-Dependent functional Magnetic-Resonance-Imaging (BOLD fMRI) og Diffusion Tensor Imaging (DTI) er spesialiserte MR-teknikker for avbildning av henholdsvis funksjonelle områder i grå substans og nevronale forbindelser i hvit substans. Ved å bearbeide BOLD fMRI bildene kan man kartlegge funksjonelle områder i hjernen og visualisere dem i form av fargekart for eksempel overlagt på anatomiske MRbilder. Ved å bearbeide DTI bildene med en teknikk som heter Diffusion Tensor Tractography (DTT) kan man kartlegge nevronale forbindelser i hjernen og visualisere dem som ”fiber-bunter”. Resultatet fra disse undersøkelsene kan være til hjelp ved planlegging og reseksjon av hjernesvulster fordi disse metodene gir informasjon om funksjonen i grå og hvit substans som ligger i nærheten av svulsten. Dermed kan man operere bort mest mulig av svulsten uten å skade disse viktige funksjonelle områdene under operasjonen. Slik funksjonell informasjon fra BOLD fMRI og DTT kan integreres i nevronavigasjons-systemer og brukes under selve operasjonen. Det overordnede målet med arbeidet bak denne avhandlingen har vært å utvikle, implementere og evaluere BOLD fMRI og DTT ved 3 Tesla for rutinemessig bruk i forbindelse med prekirurgisk planlegging og funksjonell nevronavigasjon kombinert med minimal invasiv nevrokirurgi. En første tilnærming til å utvikle BOLD fMRI oppgaver for bruk til kartlegging av viktige områder i hjernebarken hos pasienter er å samle inn normgivende funksjonelle data i friske individer. Vi undersøkte derfor et utvalg motoriske oppgaver med BOLD fMRI i friske forsøkspersoner, for deretter å evaluere hvilke som var best egnet for funksjonell kartlegging og framstilling av det primære motoriske området. Bevegelse av fingre, tær og tunge var de oppgavene med høyest suksses-rate i friske frivillige og viste seg også å fungere med like stor grad av suksses for pasienter med hjernesvulster. Vi har også undersøkt et utvalg språkoppgaver i friske forsøkspersoner for å evaluere reproduserbarhet og grad av lateralisering av språkaktiveringene i de enkelte oppgavene, for å bestemme hvilke oppgaver som er best egnet til å kartlegge de fremre og bakre språkområdene. Vi fant at en ordgenererings-oppgave var best egnet for kartlegging av det fremre språkområdet, mens en navngivings-oppgave var best egnet for det bakre området. Vi har også utviklet en ny språkoppgave med potensialet for samtidig kartlegging av både det fremre og bakre språkområdet i en og samme undersøkelse. Denne oppgave har i tillegg fordelen av å være mer engasjerende å utføre, noe som kan hjelpe personen som utfører oppgaven til å beholde konsentrasjonen og motivasjonen gjennom hele undersøkelsen. Vi har også evaluert bruken av BOLD fMRI og DTT i ultralyd-veiledet funksjonell nevronavigasjon ved å retrospektivt gå igjennom et 3-års materiale med pasienter operert på denne måten. Her fant vi at fjerning av hjernesvulstvev ga en signifikant forbedring i klinisk status etter 3 måneder sammenlignet med før operasjonen. For gliomene fant vi et gjennomsnittelig gjenværende svulst volum på 11% etter operasjonen. Vi fant også en signifikant korrelasjon mellom avtagende avstand mellom tumor og funksjonelt område og økende gjenværende svulstvolum etter operasjonen. Dette tyder på at operasjonene er gjennomført som et kompromiss mellom å fjerne så mye svulstvev som mulig uten å samtidige risikere nye nevrologiske utfall. Det var imidlertid noen pasienter med avstand mellom tumor og funksjonelt område på mindre enn 2 mm som ble radikalt operert uten nye nevrologiske utfall etter operasjonen. Dette tyder på at funksjonell nevronavigasjon med oppdatert anatomisk informasjon fra 3D ultralyd under operasjonen gir nevrokirurgene en fordel når de opererer, samt muliggjør så mye fjerning av svulsten som mulig uten å påføre nye nevrologiske utfall. Utfordringene i den videre bruken av disse teknikkene består i å etablere standardiserte oppgaver og analyser for tolkning av disse undersøkelsene, samt å planlegge og utføre kontrollerte kliniske forsøk, enten i form av prospektive oppfølgings studier eller randomiserte studier, for å evaluere effekten av prekirurgisk BOLD fMRI og DTT på morbiditet og mortalitet i pasienter med hjernelesjoner.Blood-Oxygenation-Level-Dependent functional Magnetic-Resonance-Imaging (BOLD fMRI) and Diffusion Tensor Imaging (DTI) are specialized MRI-techniques for imaging of eloquent cortices and neural tracts in gray and white matter, respectively. By processing of the BOLD fMRI images, it is possible to map eloquent cortices and visualize them as statistical parametric color coded maps to be overlain on for instance anatomical MRI-images. Processing of the DTI images using a technique called Diffusion Tensor Tractography (DTT), makes it possible to map important neural tracts and visualize them as fiber bundles. The results from these examinations may be helpful during planning and resection of brain lesions, by providing information on functional eloquent cortices and important white matter tracts in close proximity to the lesion, as the goal of surgery is to maximize resection without inflicting new neurological deficits. This functional information may also be incorporated into neuronavigation systems and utilized during surgery. The overall aim of this thesis was to develop, implement, and evaluate BOLD fMRI and DTT at 3 Tesla for routine use in preoperative planning and 3D ultrasound-guided functional neuronavigation combined with minimal invasive neurosurgery. Obtaining normative functional data in healthy subjects is a first step in the development of clinical useful tasks. Thus, we investigated different motor tasks in a group of healthy subjects to evaluate which combination was best suited for functional mapping and delineation of the primary motor cortex. Movement of fingers, toes, and tongue yielded the highest success rates in healthy subjects and proved equally successful in patients with brain lesions. We also investigated a set of language tasks and the reproducibility of the activation size and location for these. We found that a word-generation task and a responsive naming task should be preferred for mapping of the frontal and temporal language area, respectively. A novel language task with the potential to map both the frontal and temporal language areas was also established. This task has the advantage of being more engaging, which may help the subjects to maintain concentration and stay motivated throughout the scanning session. We have also evaluated the use of BOLD fMRI and DTT in 3D ultrasound-guided functional neuronavigation by retrospectively reviewing patients operated during a threeyear period. We found that surgery gave an overall significant improvement in clinical status compared to preoperatively, and for gliomas we found a median residual tumor volume of 11%. We also found a significant correlation between decreasing lesion-toeloquent- area distance and increasing residual tumor percentage in gliomas, indicating that the resections were performed as a compromise between removing as much tumor tissue as possible without jeopardizing eloquent areas. Furthermore, some glioma patients with lesion-to-eloquent-area distance less than 2 mm also had radical resections without post-operative neurological deficits. Thus indicating that guided functional neuronavigation with updated anatomical information using 3D ultrasound gives the surgeon an advantage when resecting brain lesions, as well as facilitates maximal tumor resection with minimal deficit. The challenges ahead lie in establishing standardized tasks and analysis for processing of these investigations, as well as carrying out prospective outcome studies or clinical randomized trials in order to produce evidence for effect of presurgical BOLD fMRI and DTT on morbidity and mortality in patients with brain lesions

Normative data for pituitary size and volume in the general population between 50 and 66 years

Purpose The main aim of this study was to provide normative data for pituitary height and volume in persons between 50 and 66 years in the general population. The secondary aim was to establish a convenient surrogate marker of pituitary size for use in routine radiological practice. Methods From a geographically defined prospective healthy study, 1006 participants between 50 and 66 years had a brain MRI, of which 988 (519 women) were included in this study. We measured the mid-sagittal height, max-sagittal height and total volume of the anterior pituitary lobe based on T1-weighted 3D MRI images. Results Both the mean mid-sagittal and max-sagittal pituitary height were signifcantly larger in women compared to men, with 4.9±1.7 mm versus 4.4±1.4 mm (p<.001) for the mean mid-sagittal height and 6.8±1.2 mm versus 6.1±1.1 mm (p<0.001) for the mean max-sagittal height. The mean anterior pituitary lobe volume was also signifcantly larger in women than in men (494±138 mm3 vs. 405±118 mm3 ) (p<0.001). There were no signifcant diferences in these pituitary sagittal heights nor volume in either sex between the age groups 50–54, 55–59 and 60–66 years. The 95th percentile for mid-sagittal height, max-sagittal height and pituitary volume was 7.7 mm, 8.6 mm and 851 mm3 for women and 6.6 mm, 7.8 mm and 610 mm3 for men. Conclusion This study show that women have a larger pituitary gland than men in the age group between 50 and 66 years and provides normative data for pituitary size estimates which can be used for clinical diagnostic purposes as well as future research

Glioblastoma Segmentation: Comparison of Three Different Software Packages

-To facilitate a more widespread use of volumetric tumor segmentation in clinical studies, there is an urgent need for reliable, user-friendly segmentation software. The aim of this study was therefore to compare three different software packages for semi-automatic brain tumor segmentation of glioblastoma; namely BrainVoyagerTM QX, ITK-Snap and 3D Slicer, and to make data available for future reference. Pre-operative, contrast enhanced T1-weighted 1.5 or 3 Tesla Magnetic Resonance Imaging (MRI) scans were obtained in 20 consecutive patients who underwent surgery for glioblastoma. MRI scans were segmented twice in each software package by two investigators. Intra-rater, inter-rater and between-software agreement was compared by using differences of means with 95% limits of agreement (LoA), Dice’s similarity coefficients (DSC) and Hausdorff distance (HD). Time expenditure of segmentations was measured using a stopwatch. Eighteen tumors were included in the analyses. Inter-rater agreement was highest for BrainVoyager with difference of means of 0.19 mL and 95% LoA from -2.42 mL to 2.81 mL. Between-software agreement and 95% LoA were very similar for the different software packages. Intra-rater, inter-rater and between-software DSC were ≥ 0.93 in all analyses. Time expenditure was approximately 41 min per segmentation in BrainVoyager, and 18 min per segmentation in both 3D Slicer and ITK-Snap. Our main findings were that there is a high agreement within and between the software packages in terms of small intra-rater, inter-rater and between-software differences of means and high Dice’s similarity coefficients. Time expenditure was highest for BrainVoyager, but all software packages were relatively time-consuming, which may limit usability in an everyday clinical setting.publishedVersio

BLI EN DEL AV GJENGEN; HVORDAN MOTIVASJONSFAKTORER KAN BIDRA TIL Å BEKJEMPE TURNOVER I HOTELLBRANSJEN.

Denne oppgaven er utarbeidet i samarbeid med et utvalg konferanse- og leisurehoteller i Oslo-området. Studiet er basert på strategier og modeller som i kontekst med vår problemstilling og våre hypoteser forsøker å belyse temaet turnover i hotellbransjen. Gruppen belyser spesifikt tematikken rundt hva som motiverer den enkelte hotellmedarbeider og hvordan hoteller jobber for å beholde kompetente medarbeidere. Oppgaven vektlegger bruk av motivasjons- og hygienefaktorer for å bekjempe den høye graden av turnover som går igjen i bransjen. Det er benyttet kvalitativ metode i gjennomføringen blant ledere på de respektive hotellavdelingene. Gruppen har valgt å benytte dybdeintervjuer for å samle inn data. Funnene fra undersøkelsen konstaterer at sosiale betingelser spiller en større rolle for de ansatte motivasjon enn tidligere antatt, og at det bør rettes et større fokus mot å sikre gode sosiale forhold på arbeidsplassen. Videre anbefales det å kontinuerlig arbeide med kompetanse- og karriereutvikling for å sikre at kompetente medarbeidere ikke slutter i sine stillinger. Det ble også oppdaget at deler av teorien kan være noe utdatert og at noen sentrale teorier om motivasjon kan ha behov for modifikasjoner

Express Team-Based Learning (eTBL): A Time-Efficient TBL Approach in Neuroradiology

Rationale and Objectives Team-based learning (TBL) is a student-centred, teacher-directed instructional method that promotes active learning. The application phase of TBL stimulates group discussion and critical thinking, which could be useful for learning radiology. We designed and evaluated two modified TBL-sessions on computed tomography and magnetic resonance imaging diagnostics in neuroradiology. Our aim was to examine what effects engaging students in in-class team application tasks had on student learning. Materials and Methods A cross-over study was conducted, including 105 third-year medical students using two modified TBL sessions as the active learning intervention compared with two traditional lectures as a control. Student learning was assessed by results on the neuroradiology part of the end-of-year written examination. Student engagement and perceptions were assessed using the Student Self-Report of Engagement Measure and an additional four Likert-type items. Results There were no statistically significant differences in student scores on the examination. Students reported high levels of engagement, and reported being more satisfied overall with the TBL sessions than traditional lectures. Students rated the TBL sessions higher than lectures on ability to make difficult material comprehensible, ability to engage students and to give them feedback. Conclusion The modified TBL sessions halved in-class teaching time and by omitting the readiness assurance tests, there was more in-class time to focus on problem-solving of real clinical cases. Moreover, shorter sessions may ease implementation of TBL in the curriculum and allow for more frequent sessions. Students were more satisfied with eTBL than lectures, and reported high levels of engagement

The Direction of Tumour Growth in Glioblastoma Patients

Generating MR-derived growth pattern models for glioblastoma multiforme (GBM) has been an attractive approach in neuro-oncology, suggesting a distinct pattern of lesion spread with a tendency in growing along the white matter (WM) fibre direction for the invasive component. However, the direction of growth is not much studied in vivo. In this study, we sought to study the dominant directions of tumour expansion/shrinkage pre-treatment. We examined fifty-six GBMs at two time-points: at radiological diagnosis and as part of the pre-operative planning, both with contrast-enhanced T1-weighted MRIs. The tumour volumes were semi-automatically segmented. A non-linear registration resulting in a deformation field characterizing the changes between the two time points was used together with the segmented tumours to determine the dominant directions of tumour change. To compute the degree of alignment between tumour growth vectors and WM fibres, an angle map was calculated. Our results demonstrate that tumours tend to grow predominantly along the WM, as evidenced by the dominant vector population with the maximum alignments. Our findings represent a step forward in investigating the hypothesis that tumour cells tend to migrate preferentially along the WM