How to assess intra- and inter-observer agreement with quantitative PET using variance component analysis:a proposal for standardisation

BACKGROUND: Quantitative measurement procedures need to be accurate and precise to justify their clinical use. Precision reflects deviation of groups of measurement from another, often expressed as proportions of agreement, standard errors of measurement, coefficients of variation, or the Bland-Altman plot. We suggest variance component analysis (VCA) to estimate the influence of errors due to single elements of a PET scan (scanner, time point, observer, etc.) to express the composite uncertainty of repeated measurements and obtain relevant repeatability coefficients (RCs) which have a unique relation to Bland-Altman plots. Here, we present this approach for assessment of intra- and inter-observer variation with PET/CT exemplified with data from two clinical studies. METHODS: In study 1, 30 patients were scanned pre-operatively for the assessment of ovarian cancer, and their scans were assessed twice by the same observer to study intra-observer agreement. In study 2, 14 patients with glioma were scanned up to five times. Resulting 49 scans were assessed by three observers to examine inter-observer agreement. Outcome variables were SUVmax in study 1 and cerebral total hemispheric glycolysis (THG) in study 2. RESULTS: In study 1, we found a RC of 2.46 equalling half the width of the Bland-Altman limits of agreement. In study 2, the RC for identical conditions (same scanner, patient, time point, and observer) was 2392; allowing for different scanners increased the RC to 2543. Inter-observer differences were negligible compared to differences owing to other factors; between observer 1 and 2: −10 (95 % CI: −352 to 332) and between observer 1 vs 3: 28 (95 % CI: −313 to 370). CONCLUSIONS: VCA is an appealing approach for weighing different sources of variation against each other, summarised as RCs. The involved linear mixed effects models require carefully considered sample sizes to account for the challenge of sufficiently accurately estimating variance components. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12880-016-0159-3) contains supplementary material, which is available to authorized users

Which Tumor Suppressor Gene Plays an Important Role in Oncogenesis of Oral Cancer?

口腔領域癌の遺伝子学的解析はあまり行われていないため, 本稿では当科における癌抑制遺伝子異常の検索結果を用いて, 口腔癌においてどの遺伝子が重要な役割を果たしているのかを検討した。試料は, 口腔扁平上皮癌組織と, 同一症例の正常組織を用いた。RB遺伝子とWT遺伝子についてはサザンブロッティング法により, また, APC, P53, VHL, p15, p16, p18遺伝子についてはPCR-SSCP法および塩基配列決定法を用いて検索した。さらに, APC遺伝子についてはエクソン11のポリモルフィズムを利用したPCR-LOH分析をあわせて行った。以下に示す結果を得た。(1)APC遺伝子の点突然変異は8.3%, APC-LOHは informative 症例中の72.7%に認められた。(2)p16遺伝子とp18遺伝子の点突然変異はそれぞれ4.0%, 3.8%に認められた。p15遺伝子異常は認められなかった。(3)p53心遺伝子異常は7.7%に認められた。(4)WT遺伝子の部分欠失を6.5%に認めた。(5)RB遺伝子とVHL遺伝子の異常は認められなかった。以上の結果から, 種々の癌抑制遺伝子のうち, 特にAPC遺伝子が口腔扁平上皮癌発生に重要な役割を果たしていることが示唆された。Since there are few molecular biological studies on oral cancer, we evaluated genes which would play an important role in the oncogenesis of oral cancer based on our previous studies. To elucidate whether or not abnormalities of RB and WT genes could contribute to the development of oral squamous-cell carcinoma (SCC), genomic DNAs obtained from tumors and corresponding normal tissues were examined with Southern blotting. On the other hand, PCR-SSCP (polymerase chain reaction single-strand conformation polymorphism) and sequence analyses were performed to detect possible mutations of APC, VHL, p15, p16, p18 and p53. We also examined the tissue samples to detect loss of heterozygosity (LOH) at exon 11 of APC gene by PCR-LOH assay. We obtained the following results: (1) Point mutations of APC gene in tumor tissues were identified in 8.3(nil)atients with oral SCC, and PCR-LOH assay revealed LOH at exon 11 of APC gene in 72.71024720030f informative cases. (2) Point mutations of p16 and p18 genes were detected in 4.0-0x1.db55b085084p-148nd 3.80f oral SCC patients, respectively. However, no mutation of p15 gene was found. (3) Abnormalities of p53 gene were detected in 7.726725462457f all cases. (4) Southern blotting revealed partial deletions and rearrangements of WT gene in 6.50f the cases. (5) No abnormality of VHL and RB genes was detected in any of the cases. These results suggest that APC gene is most significantly associated with the development of human oral SCC among the known tumor suppressor genes

Assessing the Environmental Costs and Benefits of Households Electricity Consumption Management

In this study the environmental costs and benefits of smart metering technology systems installed in households in Norway have been assessed. Smart metering technology systems enable mechanisms to manage electricity consumption by shifting loads. With the use of Life Cycle Assessment (LCA) and the ReCiPe method for impact assessment, the life cycle impacts of installation and operation of a system in a household have been found. Environmental benefits of using the systems to manage electricity consumption have been quantified. The results of the study indicated that the environmental costs of smart metering technology systems mainly are caused by the production of system components and system electricity use during operation. For the production of system components, the use of electronics in the components was generally the major contributor to the total environmental impacts. Further, the systems metal depletion potential was high relative to other environmental impacts after normalization in impact assessment. The main environmental benefits of smart metering technology systems in a Norwegian perspective will be in a critical supply situation of electricity to avoid use of reserve capacity gas power plants, and the results from the study showed that the systems in such a case can contribute to an avoided emission of greenhouse gases. Load shifting from a general basis may however not always have environmental benefits and this will depend on the existing alternatives for electricity production

Prakademikeren. En studie av kunnskapsarbeid.

Ordet ”prakademiker” er sammensatt av begrepene praktiker og akademiker, og det er en betegnelse på akademikere som søker å utvikle sine ferdigheter i praktiske kontekster utenfor universitetene. Jeg har i oppgaven vist at ”prakademikeren” vil ha en spesiell posisjon siden han/hun kan teste ut i praksis hvordan hans/hennes teorier ser ut til å virke. I oppgaven har jeg fulgt det grove skillet mellom strukturelt syn og prosessuelt syn på kunnskap, og kunnskapsarbeidet ses ut fra ”prakademikernes” egne perspektiver. Jeg valgte å studere to ”prakademikere”, og har gjort intervjuer for å få tilgang til deres opplevelser. Den ene framsto som mer strukturelt orientert mens den andre inntok et mer eksplisitt prosessuelt syn. Ved å kontrastere disse to ”prakademikerne” har jeg fått innsyn i hvordan forholdet er mellom kunnskapsperspektiv og praktisk kunnskapsarbeid

Arkivvitenskapelig paradigmeteori. En studie i Terry Cooks arkivvitenskapelige perspektiver med vekt på endringene i fag og vitenskap etter 1980, og forståelsen av norsk politikk for arkiv og dokumentasjonsforvaltning 1990-2022

Diskusjonen rundt eksistensen av arkivvitenskapelige paradigmer har pågått i arkivmiljøer innenfor akademia og i noen grad også praksisfeltet siden 1980-årene. Med utgangspunkt i Terry Cooks artikkel «Evidence, Memory, Identity, and Community. Four Shifting Archival Paradigms» fra 2013, lovarbeid og rapporter, drøfter dette essayet hvorvidt norsk politikk for arkiv og dokumentasjonsforvaltning kan sies å ha tatt opp i seg teoretiske elementer fra arkivmiljøer og -teoretikere i andre land. Cooks paradigmebeskrivelser er ikke tilstrekkelige til alene å forklare utviklingen for dokumentasjonsforvaltning i Norge, men forutsetter en sterk og selvstendig demokratiteoretisk utvikling som blir samvirkende med de forholdene Cook peker på. Dette kan sies å ha bidratt til en tydeliggjøring og styrking av sammenhengen mellom demokrati og arkiv, og av forståelsen av arkiv som en demokratiserende samfunnsressurs.publishedVersio

Påbudt å kartlegge egnethet for ombruk ved riving

Nå må du kartlegge hvilke deler som kan få nytt liv, om du skal rive en bygning. Byggforskserien gir gode råd om prosessen.publishedVersio

Perspectives on learning in view of changes and challenges for records management within the Norwegian public sector

Artikkelen bygger på et bredt grunnlag av dybdeintervjuer med ansatte i flere yrkesgrupper i norsk kommunal og statlig forvaltning, og tar fatt i problemsituasjonen i dokumentasjonsforvaltning i offentlig sektor. Det gjelder manglende arkivering og sviktende rutiner for journalføring, mangler som er beskrevet i offentlige utredninger og rapporter fra blant andre Arkivverket og Riksrevisjonen, som er sentrale tilsyns- og revisjonsorganer for sektoren. Jeg diskuterer disse utfordringene på bakgrunn av den ansvars- og oppgaveoverføring som har funnet sted i offentlig sektor i kjølvannet av digitaliseringsprosesser, og som har medført at saksbehandlere nå selv må utføre det som tidligere ble ansett som oppgaver for virksomhetenes arkivtjenester. Et sentralt spørsmål er hvordan og i hvilken grad ansatte i offentlig sektor har fått tilført kunnskap og kompetanse om arkivering og dokumentasjonsforvaltning, og hvor bredt spekter av kunnskap og kompetanse som har blitt overført. Jeg diskuterer også disse spørsmålene ut fra mer allmenn teori om kunnskapsoverføring og læring i organisasjoner, og ser om det på basis av mine undersøkelser er mulig å si noe om tilstedeværelse av faktorer med potensiale for å fremme eller hemme kunnskapsoverføring og læring i virksomhetene.The article is based on in-depth interviews with several public officials in various occupational categories in municipal and state administration and addresses the problem situation concerning records management in the Norwegian public sector. It concerns a lack of archiving and failing routines for record-keeping, shortcomings that are described in several reports from audit and supervisory bodies central to the sector. I’m discussing these challenges in view of the transfer of tasks and responsibilities that has taken place in the Norwegian public sector in the wake of digitalization. As a result of this transfer, case managers must now perform tasks previously performed by the organization’s record managers. An important question is how and to what extent employees in the public sector have acquired knowledge and expertise regarding records management, and how wide a range of knowledge and skills have been transferred. I discuss these questions in view of more general theory of knowledge transfer and learning within organizations and see if my material gives any insight as to the presence of factors with a potential to promote or inhibit knowledge transfer and organizational learning.publishedVersio

X ray emission spectroscopy of bulk liquid water in no man s land

The structure of bulk liquid water was recently probed by x ray scattering below the temperature limit of homogeneous nucleation TH of amp; 8764;232 K [J. A. Sellberg et al., Nature 510, 381 384 2014 ]. Here, we utilize a similar approach to study the structure of bulk liquid water below TH using oxygen K edge x ray emission spectroscopy XES . Based on previous XES experiments [T. Tokushima et al., Chem. Phys. Lett. 460, 387 400 2008 ] at higher temperatures, we expected the ratio of the 1b1 amp; 8242; and 1b1 amp; 8242; amp; 8242; peaks associated with the lone pair orbital in water to change strongly upon deep supercooling as the coordination of the hydrogen H bonds becomes tetrahedral. In contrast, we observed only minor changes in the lone pair spectral region, challenging an interpretation in terms of two interconverting species. A number of alternative hypotheses to explain the results are put forward and discussed. Although the spectra can be explained by various contributions from these hypotheses, we here emphasize the interpretation that the line shape of each component changes dramatically when approaching lower temperatures, where, in particular, the peak assigned to the proposed disordered component would become more symmetrical as vibrational interference becomes more importan

Ensemble methods and data augmentation by noise addition applied to the analysis of spectroscopic data

Near-infrared spectroscopy has gained great acceptance in the industry due to its multiple applications and versatility. Sometimes, however, the construction of accurate and robust calibration models involves the collection of a large number of samples with related reference analysis that can complicate and prolong the calibration stage. In this paper, ensemble methods and data augmentation by noise simulation have been applied to spectroscopic data in combination with PLSR to obtain robust models able to handle different types of perturbations likely to affect NIR data. Several types of noise have been investigated as well as different ensemble methods focused on obtaining robust PLS models able to predict both the original and the perturbed test data. The suitability of ensemble methods to perform robust calibration models has been investigated and compared to extended multiplicative signal correction (EMSC) and other calibration approaches in a real case of temperature compensation. Extended multiplicative signal correction (EMSC) and ensemble methods seem to be the most appropriate methods yielding the best results in terms of accuracy and prediction ability with a reduced calibration data set