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- Botvinik-Nezer, Rotem, et al.
(författare)
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Variability in the analysis of a single neuroimaging dataset by many teams
- 2020
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 582, s. 84-88
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Tidskriftsartikel (refereegranskat)abstract
- Data analysis workflows in many scientific domains have become increasingly complex and flexible. Here we assess the effect of this flexibility on the results of functional magnetic resonance imaging by asking 70 independent teams to analyse the same dataset, testing the same 9 ex-ante hypotheses(1). The flexibility of analytical approaches is exemplified by the fact that no two teams chose identical workflows to analyse the data. This flexibility resulted in sizeable variation in the results of hypothesis tests, even for teams whose statistical maps were highly correlated at intermediate stages of the analysis pipeline. Variation in reported results was related to several aspects of analysis methodology. Notably, a meta-analytical approach that aggregated information across teams yielded a significant consensus in activated regions. Furthermore, prediction markets of researchers in the field revealed an overestimation of the likelihood of significant findings, even by researchers with direct knowledge of the dataset(2-5). Our findings show that analytical flexibility can have substantial effects on scientific conclusions, and identify factors that may be related to variability in the analysis of functional magnetic resonance imaging. The results emphasize the importance of validating and sharing complex analysis workflows, and demonstrate the need for performing and reporting multiple analyses of the same data. Potential approaches that could be used to mitigate issues related to analytical variability are discussed. The results obtained by seventy different teams analysing the same functional magnetic resonance imaging dataset show substantial variation, highlighting the influence of analytical choices and the importance of sharing workflows publicly and performing multiple analyses.
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2. |
- Niemi, MEK, et al.
(författare)
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- 2021
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swepub:Mat__t
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3. |
- Kanai, M, et al.
(författare)
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- 2023
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swepub:Mat__t
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4. |
- Bertovic, M., et al.
(författare)
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Methods for quantification and integration of human factors into probability of detection assessments
- 2023
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Ingår i: Insight. - : British Institute of Non-Destructive Testing (BINDT). - 1354-2575 .- 1754-4904. ; 65:7, s. 364-372
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Tidskriftsartikel (refereegranskat)abstract
- Human factors (HFs) are a frequently mentioned topic when talking about the reliability of non-destructive testing (NDT). However, probability of detection (POD), the commonly used measure of NDT reliability, only looks at the technical capability of an NDT system to detect a defect. After several decades of research on the influence of HFs on NDT reliability, there is still no commonly accepted approach to rendering HFs visible in reliability assessment. This paper provides an overview of possible quantitative and qualitative methods for integrating HFs into the reliability assessment. It is concluded that reliability assessment is best carried out using both quantifiable and non-quantifiable approaches to HFs.
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5. |
- Wall, Anders, et al.
(författare)
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E-Cigarette Aerosol Deposition and Disposition of [C-11]Nicotine Using Positron Emission Tomography : A Comparison of Nicotine Uptake in Lungs and Brain Using Two Different Nicotine Formulations
- 2022
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Ingår i: Pharmaceuticals. - : MDPI. - 1424-8247. ; 15:3
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Tidskriftsartikel (refereegranskat)abstract
- Smoking is a cause of serious disease in smokers. Electronic cigarettes, delivering aerosolized nicotine, offer adult smokers a potentially less harmful alternative to combustible cigarettes. This explorative PET/CT study investigated the distribution and deposition of inhaled [C-11]nicotine using the myblu (TM) e-cigarette with two nicotine formulations, freebase and lactate salt. Fifteen healthy adult smokers participated in the two-part study to assess the distribution and accumulation of [C-11]nicotine in the respiratory pathways and brain. Time-activity data for the respiratory pathways, lungs, oesophagus and brain were derived. 31-36% of both inhaled tracer formulations accumulated in the lung within 15-35 s. [C-11]Nicotine(freebase) exhibited higher uptake and deposition in the upper respiratory pathways. For [C-11]nicotine(lactate), brain deposition peaked at 4-5%, with an earlier peak and a steeper decline. A different kinetic profile was obtained for [C-11]nicotine(lactate) with lower tracer uptake and accumulation in the upper respiratory pathways and an earlier peak and a steeper decline in lung and brain. Using nicotine lactate formulations in e-cigarettes may thus contribute to greater adult smoker acceptance and satisfaction compared to freebase formulations, potentially aiding a transition from combustible cigarettes and an acceleration of tobacco harm reduction initiatives.
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6. |
- Wechalekar, Ashutosh, et al.
(författare)
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Pharmacodynamic evaluation and safety assessment of treatment with antibodies to serum amyloid P component in patients with cardiac amyloidosis : an open-label Phase 2 study and an adjunctive immuno-PET imaging study
- 2022
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Ingår i: BMC Cardiovascular Disorders. - : BioMed Central (BMC). - 1471-2261 .- 1471-2261. ; 22:1
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Tidskriftsartikel (refereegranskat)abstract
- Background In a Phase I study treatment with the serum amyloid P component (SAP) depleter miridesap followed by monoclonal antibody to SAP (dezamizumab) showed removal of amyloid from liver, spleen and kidney in patients with systemic amyloidosis. We report results from a Phase 2 study and concurrent immuno-positron emission tomography (PET) study assessing efficacy, pharmacodynamics, pharmacokinetics, safety and cardiac uptake (of dezamizumab) following the same intervention in patients with cardiac amyloidosis. Methods Both were uncontrolled open-label studies. After SAP depletion with miridesap, patients received <= 6 monthly doses of dezamizumab in the Phase 2 trial (n = 7), <= 2 doses of non-radiolabelled dezamizumab plus [Zr-89]Zr-dezamizumab (total mass dose of 80 mg at session 1 and 500 mg at session 2) in the immuno-PET study (n = 2). Primary endpoints of the Phase 2 study were changed from baseline to follow-up (at 8 weeks) in left ventricular mass (LVM) by cardiac magnetic resonance imaging and safety. Primary endpoint of the immuno-PET study was [Zr-89]Zr-dezamizumab cardiac uptake assessed via PET. Results Dezamizumab produced no appreciable or consistent reduction in LVM nor improvement in cardiac function in the Phase 2 study. In the immuno-PET study, measurable cardiac uptake of [Zr-89]Zr-dezamizumab, although seen in both patients, was moderate to low. Uptake was notably lower in the patient with higher LVM. Treatment-associated rash with cutaneous small-vessel vasculitis was observed in both studies. Abdominal large-vessel vasculitis after initial dezamizumab dosing (300 mg) occurred in the first patient with immunoglobulin light chain amyloidosis enrolled in the Phase 2 study. Symptom resolution was nearly complete within 24 h of intravenous methylprednisolone and dezamizumab discontinuation; abdominal computed tomography imaging showed vasculitis resolution by 8 weeks. Conclusions Unlike previous observations of visceral amyloid reduction, there was no appreciable evidence of amyloid removal in patients with cardiac amyloidosis in this Phase 2 trial, potentially related to limited cardiac uptake of dezamizumab as demonstrated in the immuno-PET study. The benefit-risk assessment for dezamizumab in cardiac amyloidosis was considered unfavourable after the incidence of large-vessel vasculitis and development for this indication was terminated. Trial registration NCT03044353 (2 February 2017) and NCT03417830 (25 January 2018).
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