Perceived risk of lock-in in the front-end phase of major transportation projects

Lock-in is defined as the tendency to continue with an inefficient decision or project proposal. The front-end phase is critical to project success, yet most studies have focused on lock-in in the implementation phase. Moreover, little is known about the way in which decision-makers perceive the risk of lock-in. In this paper we identify determinants of lock-in in the front-end phase and we reveal decision-makers’ perceptions of risk of lock-in. Our findings show that risk attitudes towards lock-in vary with the level of risk aversion. However, this is not sufficiently acute to drive the level of regret needed to avoid lock-in. This implies that decision-makers do not accurately assess the risk of lock-in and as such their risk perceptions are a mediating factor in the formation of lock-in. Based on escalation of commitment, path dependency, and prospect theory, the main contribution lies in providing a more comprehensive understanding of lock-in in the front-end phase

Second opinion basisgegevens anders betalen voor mobiliteit

Dit rapport bevat een second opinion bij onderzoek van Ecorys. Ecorys heeft ten behoeve van de invoering van een kilometerprijs het autopark en het aantal autokilometers onderzocht. De studie van Ecorys is in de meeste opzichten zorgvuldig en adequaat uitgevoerd. De opmerkingen in deze second opinion betreffen uitzonderingen op deze algemene observatie. Ten eerste blijkt de omvang van het autopark in Nederland niet eenvoudig te meten, ondanks de inspanningen van Ecorys. Er zijn ruim 100.000 personenauto’s die onder de kilometerprijs vallen maar waarover bijna niets bekend is. Ten tweede is het doel van de studie weliswaar verhelderd ten opzichte van de eerdere versie van het rapport, maar nog steeds wat abstract. Het is niet goed duidelijk waarom de gegevens van belang zijn voor de tarievenstructuur en niet voor de tarieven zelf. Ten derde is het jammer dat in het overzicht van inkomsten uit autobelastingen in hoofdstuk 7 de opbrengst van de provinciale opcenten op de Motorrijtuigenbelasting niet is meegenomen. Tot slot een opmerking die niets afdoet aan de kwaliteit van de rapportage zelf. Het rapport is geschreven in de periode dat de kilometerheffing nog niet controversieel was verklaard. De veronderstelling dat de kilometerheffing ingevoerd wordt, lijkt nu achterhaald, al kan het onderwerp tijdens de kabinetsformatie weer op de agenda komen

Primary Care Providers’ Perceptions of the Acceptability, Appropriateness, and Feasibility of a Mammography Decision Aid for Women Aged 75 and Older

Background. Clinicians need to find decision aids (DAs) useful for their successful implementation. Therefore, we aimed to conduct an exploratory study to learn primary care clinicians? (PCPs) perspectives on a mammography DA for women ≥75 to inform its implementation. Methods. We sent a cross-sectional survey to 135 PCPs whose patients had participated in a randomized trial of the DA. These PCPs practiced at 1 of 11 practices in Massachusetts or North Carolina. PCPs were asked closed-ended and open-ended questions on shared decision making (SDM) around mammography with women ≥75 and on the DA?s acceptability, appropriateness, and feasibility. Results. Eighty PCPs participated (24 [30%] from North Carolina). Most (n = 69, 86%) thought that SDM about mammography with women ≥75 was extremely/very important and that they engaged women ≥75 in SDM around mammography frequently/always (n = 49, 61%). Regarding DA acceptability, 60% felt the DA was too long. Regarding appropriateness, 70 (89%) thought it was somewhat/very helpful and that it would help patients make more informed decisions; 55 (70%) would recommend it. Few (n = 6, 8%) felt they had other resources to support this decision. Regarding feasibility, 53 (n = 67%) thought it would be most feasible for patients to receive the DA before a visit from medical assistants rather than during or after a visit or from health educators. Most (n = 62, 78%) wanted some training to use the DA. Limitations. Sixty-nine percent of PCPs in this small study practiced in academic settings. Conclusions. Although PCPs were concerned about the DA?s length, most found it helpful and informative and felt it would be feasible for medical assistants to deliver the DA before a visit. Implications. Study findings may inform implementation of this and other DAs

The genetic architecture of the human cerebral cortex

INTRODUCTION The cerebral cortex underlies our complex cognitive capabilities. Variations in human cortical surface area and thickness are associated with neurological, psychological, and behavioral traits and can be measured in vivo by magnetic resonance imaging (MRI). Studies in model organisms have identified genes that influence cortical structure, but little is known about common genetic variants that affect human cortical structure. RATIONALE To identify genetic variants associated with human cortical structure at both global and regional levels, we conducted a genome-wide association meta-analysis of brain MRI data from 51,665 individuals across 60 cohorts. We analyzed the surface area and average thickness of the whole cortex and 34 cortical regions with known functional specializations. RESULTS We identified 306 nominally genome-wide significant loci (P < 5 × 10−8) associated with cortical structure in a discovery sample of 33,992 participants of European ancestry. Of the 299 loci for which replication data were available, 241 loci influencing surface area and 14 influencing thickness remained significant after replication, with 199 loci passing multiple testing correction (P < 8.3 × 10−10; 187 influencing surface area and 12 influencing thickness). Common genetic variants explained 34% (SE = 3%) of the variation in total surface area and 26% (SE = 2%) in average thickness; surface area and thickness showed a negative genetic correlation (rG = −0.32, SE = 0.05, P = 6.5 × 10−12), which suggests that genetic influences have opposing effects on surface area and thickness. Bioinformatic analyses showed that total surface area is influenced by genetic variants that alter gene regulatory activity in neural progenitor cells during fetal development. By contrast, average thickness is influenced by active regulatory elements in adult brain samples, which may reflect processes that occur after mid-fetal development, such as myelination, branching, or pruning. When considered together, these results support the radial unit hypothesis that different developmental mechanisms promote surface area expansion and increases in thickness. To identify specific genetic influences on individual cortical regions, we controlled for global measures (total surface area or average thickness) in the regional analyses. After multiple testing correction, we identified 175 loci that influence regional surface area and 10 that influence regional thickness. Loci that affect regional surface area cluster near genes involved in the Wnt signaling pathway, which is known to influence areal identity. We observed significant positive genetic correlations and evidence of bidirectional causation of total surface area with both general cognitive functioning and educational attainment. We found additional positive genetic correlations between total surface area and Parkinson’s disease but did not find evidence of causation. Negative genetic correlations were evident between total surface area and insomnia, attention deficit hyperactivity disorder, depressive symptoms, major depressive disorder, and neuroticism. CONCLUSION This large-scale collaborative work enhances our understanding of the genetic architecture of the human cerebral cortex and its regional patterning. The highly polygenic architecture of the cortex suggests that distinct genes are involved in the development of specific cortical areas. Moreover, we find evidence that brain structure is a key phenotype along the causal pathway that leads from genetic variation to differences in general cognitive function

Altered white matter microstructural organization in posttraumatic stress disorder across 3047 adults: results from the PGC-ENIGMA PTSD consortium

A growing number of studies have examined alterations in white matter organization in people with posttraumatic stress disorder (PTSD) using diffusion MRI (dMRI), but the results have been mixed which may be partially due to relatively small sample sizes among studies. Altered structural connectivity may be both a neurobiological vulnerability for, and a result of, PTSD. In an effort to find reliable effects, we present a multi-cohort analysis of dMRI metrics across 3047 individuals from 28 cohorts currently participating in the PGC-ENIGMA PTSD working group (a joint partnership between the Psychiatric Genomics Consortium and the Enhancing NeuroImaging Genetics through Meta-Analysis consortium). Comparing regional white matter metrics across the full brain in 1426 individuals with PTSD and 1621 controls (2174 males/873 females) between ages 18-83, 92% of whom were trauma-exposed, we report associations between PTSD and disrupted white matter organization measured by lower fractional anisotropy (FA) in the tapetum region of the corpus callosum (Cohen's d = -0.11, p = 0.0055). The tapetum connects the left and right hippocampus, for which structure and function have been consistently implicated in PTSD. Results were consistent even after accounting for the effects of multiple potentially confounding variables: childhood trauma exposure, comorbid depression, history of traumatic brain injury, current alcohol abuse or dependence, and current use of psychotropic medications. Our results show that PTSD may be associated with alterations in the broader hippocampal network.New methods for child psychiatric diagnosis and treatment outcome evaluatio

Neuroimaging-based classification of PTSD using data-driven computational approaches: a multisite big data study from the ENIGMA-PGC PTSD consortium

Background: Recent advances in data-driven computational approaches have been helpful in devising tools to objectively diagnose psychiatric disorders. However, current machine learning studies limited to small homogeneous samples, different methodologies, and different imaging collection protocols, limit the ability to directly compare and generalize their results. Here we aimed to classify individuals with PTSD versus controls and assess the generalizability using a large heterogeneous brain datasets from the ENIGMA-PGC PTSD Working group. Methods: We analyzed brain MRI data from 3,477 structural-MRI; 2,495 resting state-fMRI; and 1,952 diffusion-MRI. First, we identified the brain features that best distinguish individuals with PTSD from controls using traditional machine learning methods. Second, we assessed the utility of the denoising variational autoencoder (DVAE) and evaluated its classification performance. Third, we assessed the generalizability and reproducibility of both models using leave-one-site-out cross-validation procedure for each modality. Results: We found lower performance in classifying PTSD vs. controls with data from over 20 sites (60 % test AUC for s-MRI, 59 % for rs-fMRI and 56 % for D-MRI), as compared to other studies run on single-site data. The performance increased when classifying PTSD from HC without trauma history in each modality (75 % AUC). The classification performance remained intact when applying the DVAE framework, which reduced the number of features. Finally, we found that the DVAE framework achieved better generalization to unseen datasets compared with the traditional machine learning frameworks, albeit performance was slightly above chance. Conclusion: These results have the potential to provide a baseline classification performance for PTSD when using large scale neuroimaging datasets. Our findings show that the control group used can heavily affect classification performance. The DVAE framework provided better generalizability for the multi-site data. This may be more significant in clinical practice since the neuroimaging-based diagnostic DVAE classification models are much less site-specific, rendering them more generalizable.Stress-related psychiatric disorders across the life spa

Surface chemical states on LPCVD-grown 4H-SiC epilayers

Applied Surface Science1261-234-42ASUS

Kostenoverschrijdingen in transportinfrastructuurprojecten in Nederland: Implicaties voor besluitvorming

Kostenoverschrijdingen zijn een groot en aanhoudend probleem in grootschalige transportinfrastructuurprojecten. In samenwerking met het Ministerie van Infrastructuur en Milieu heeft de TU Delft onderzoek uitgevoerd naar een groot aantal projecten in Nederland en heeft het de projectprestatie in Nederland vergeleken met dat in andere landen in de wereld. Dit artikel gaat in op de implicaties van deze resultaten op 1) de huidige besluitvorming van grootschalige projecten en 2) kostenschattingen. We bevelen aan dat er in het algemeen meer aandacht wordt besteed aan kostenschattingen, en specifiek raden we aan om de methode ‘Reference Class Forecasting’ te gebruiken bij het voorspellen van de kosten omdat die vermoedelijk tot aanzienlijke betere schattingen zal leiden. Het uitgevoerde onderzoek brengt naast de onderzoeken van de Tijdelijke Commissie Infrastructuurprojecten, de commissie Elverding en de adviescommissie Versnelling en Verbetering Besluitvorming Infrastructuur nieuwe inzichten voor de besluitvorming en de projectprestatie van Nederlandse transportinfrastructuurprojecten.Infrastructures, Systems and ServicesTechnology, Policy and Managemen