187 research outputs found
Sacred building back to the residents
No full textThe transformation of the St Jozef Church in Amsterdam West into a cultural center for the Robbert Scott neighborhood.R-MITArchitectureArchitecture and The Built Environmen
Digital biomarkers and sex impacts in Alzheimer’s disease management — potential utility for innovative 3P medicine approach
No full textDigital biomarkers are defined as objective, quantifiable physiological and behavioral data that are collected and measured by means of digital devices. Their use has revolutionized clinical research by enabling high-frequency, longitudinal, and sensitive measurements. In the field of neurodegenerative diseases, an example of a digital biomarker-based technology is instrumental activities of daily living (iADL) digital medical application, a predictive biomarker of conversion from mild cognitive impairment (MCI) due to Alzheimer’s disease (AD) to dementia due to AD in individuals aged 55 + . Digital biomarkers show promise to transform clinical practice. Nevertheless, their use may be affected by variables such as demographics, genetics, and phenotype. Among these factors, sex is particularly important in Alzheimer’s, where men and women present with different symptoms and progression patterns that impact diagnosis. In this study, we explore sex differences in Altoida’s digital medical application in a sample of 568 subjects consisting of a clinical dataset (MCI and dementia due to AD) and a healthy population. We found that a biological sex-classifier, built on digital biomarker features captured using Altoida’s application, achieved a 75% ROC-AUC (receiver operating characteristic — area under curve) performance in predicting biological sex in healthy individuals, indicating significant differences in neurocognitive performance signatures between males and females. The performance dropped when we applied this classifier to more advanced stages on the AD continuum, including MCI and dementia, suggesting that sex differences might be disease-stage dependent. Our results indicate that neurocognitive performance signatures built on data from digital biomarker features are different between men and women. These results stress the need to integrate traditional approaches to dementia research with digital biomarker technologies and personalized medicine perspectives to achieve more precise predictive diagnostics, targeted prevention, and customized treatment of cognitive decline.RLH and IT were supported by Altoida Inc. JM was supported in this work by the Charles University Grant Agency (GA UK) project no. 436119 at Charles University, Second Faculty of Medicine, Prague, Czech Republic.Peer Reviewed"Article signat per 16 autors/es: Robbert L. Harms, Alberto Ferrari, Irene B. Meier, Julie Martinkova, Enrico Santus, Nicola Marino, Davide Cirillo, Simona Mellino, Silvina Catuara Solarz, Ioannis Tarnanas, Cassandra Szoeke, Jakub Hort, Alfonso Valencia, Maria Teresa Ferretti, Azizi Seixas & Antonella Santuccione Chadha "Postprint (published version
Robust and Fast Markov Chain Monte Carlo Sampling of Diffusion MRI Microstructure Models
No full textIn diffusion MRI analysis, advances in biophysical multi-compartment modeling have gained popularity over the conventional Diffusion Tensor Imaging (DTI), because they can obtain a greater specificity in relating the dMRI signal to underlying cellular microstructure. Biophysical multi-compartment models require a parameter estimation, typically performed using either the Maximum Likelihood Estimation (MLE) or the Markov Chain Monte Carlo (MCMC) sampling. Whereas, the MLE provides only a point estimate of the fitted model parameters, the MCMC recovers the entire posterior distribution of the model parameters given in the data, providing additional information such as parameter uncertainty and correlations. MCMC sampling is currently not routinely applied in dMRI microstructure modeling, as it requires adjustment and tuning, specific to each model, particularly in the choice of proposal distributions, burn-in length, thinning, and the number of samples to store. In addition, sampling often takes at least an order of magnitude, more time than non-linear optimization. Here we investigate the performance of the MCMC algorithm variations over multiple popular diffusion microstructure models, to examine whether a single, well performing variation could be applied efficiently and robustly to many models. Using an efficient GPU-based implementation, we showed that run times can be removed as a prohibitive constraint for the sampling of diffusion multi-compartment models. Using this implementation, we investigated the effectiveness of different adaptive MCMC algorithms, burn-in, initialization, and thinning. Finally we applied the theory of the Effective Sample Size, to the diffusion multi-compartment models, as a way of determining a relatively general target for the number of samples needed to characterize parameter distributions for different models and data sets. We conclude that adaptive Metropolis methods increase MCMC performance and select the Adaptive Metropolis-Within-Gibbs (AMWG) algorithm as the primary method. We furthermore advise to initialize the sampling with an MLE point estimate, in which case 100 to 200 samples are sufficient as a burn-in. Finally, we advise against thinning in most use-cases and as a relatively general target for the number of samples, we recommend a multivariate Effective Sample Size of 2,200
Diffusion MRI analysis: robust and efficient microstructure modeling
No full textDiffusion MRI (dMRI) allows for investigating the structure of the human brain. This is useful for both scientific brain research as well as medical diagnosis. Since the raw dMRI data is not directly interpretable by humans, we use mathematical models to convert the raw dMRI data into something interpretable. These models can be computed using multiple different computational methods, each having a different trade-off in accuracy, robustness and efficiency. In this thesis we studied multiple different computational models for their usability and efficiency for dMRI modeling. In the end we provide the reader with methodological recommendations for dMRI modeling and provide a high performance GPU enabled dMRI computing platform containing all recommendations
Het huisvesten van kennis: Een plek die ons stimuleert zo vrij mogelijk te denken
No full textRobbert Dijkgraaf is sinds mei 2008 voorzitter van de Koninklijke Nederlandse Akademie van Wetenschappen. Hij is cum laude gepromoveerd, staat bekend als een briljant wetenschapper die de wetenschap toegankelijk maakt voor een groter publiek. FMI trad in gesprek met hem over wetenschappelijk denken en de huisvesting die hier het beste bij past.Real Estate and Housin
Coll., Die Welt des Islams, vol. 54, n°1, 2014
No full textChristoph Schumann
Author: Thomas Philipp Source: Volume 54, Issue 1, pp 1 –3 Materials for a History of Hungarian Academic Orientalism: The Case of Gyula Germanus Author: Adam Mestyan Source: Volume 54, Issue 1, pp 4 –33 Franz Rosenthal’s Half an Autobiography
Author: Hinrich Biesterfeldt Source: Volume 54, Issue 1, pp 34 –105 Post-Islamism in Distress? A Critical Evaluation of the Theory in Islamist-Dominated Egypt (11 February 2011-3 July 2013)
Author: Robbert A.F.L. Wolteri..
Cryostat Control: Real time control for a cryogenic refrigerator
No full textIn order to measure the spectrum of radio emissions from galaxies and other deep space objects, a new superconducting spectrometer, working at very cold temperatures close to the absolute zero, is developed. An advanced cooling system called a cryostat is used to cool down the spectrometer. The cool down of the cryostat involves the control of multiple sensors and actuators connected to the cryostat to achieve a final temperature below 250 millikelvin. A software program is used for this purpose. As extra hardware components have been added to the cryostat, the existing program does no longer fulfill the requirements. For this reason a new software program, which can monitor temperatures of all components and start control processes, is developed. The developed program consists of a client server structure. The server handles the logic of the cryostat using several controllers. It can send data to a native client, which is the graphical user interface, or a REST API. The native client displays sensor readouts received from the server and allows full control of server, which means it can start the cool down process as well as manual control processes. The REST API allows the user to have full control over the server using a Python script to achieve measurements which cannot be done from the native client. The increased automation, improved control and ability to integrate with external Python scripts allow the user to focus on the essential parts of an experiment making the developed program an improvement over the previous program
Three Way Duels: Infinite Games on the Unit Square
No full textWith the growing wealth and economy of a country, there are an increasing amount of small and big businesses. Every company has its own marketing strategy that it uses in order to lure customers away from their competition and increase their sales. Choosing the perfect time to advertise or discount several products is of essence for a company to gain more money than their competition. These type of marketing games are all slight variations of duels. The purpose of this report is to research how this duel is played most optimal when there are two or more participants. Several types of two-player duels shall be analysed first in order to understand and analyse a three-player duel.Applied Mathematic
Proving functional correctness of monadic programs using separation logic
No full textInteraction trees are an active development in representing effectful and impure pro- grams in the Coq proof assistant. Examples of programs they can represent are programs that use: mutable state, concurrency and general recursion. Besides representing these programs we also want to reason about and verify these programs using separation logic. That is the purpose of this thesis. More technically speaking interaction trees are new way to do shallow embeddings in the Coq proof assistant. They are a coinductive variant of the free monad and come with the usual constructions of events and event handlers. The aim of interaction trees is to represent impure programs and potentially non-terminating programs in their environment. Interaction trees are, in contrast to relational operational semantics, executable by interpretation or program extraction. Interaction trees come with a framework for reasoning about their behavior based on equivalency up to weak bisimulation. An open problem is to reason about interaction trees utilizing a separation logic rather than weak bisimulation. We developed Pothos as a solution to this problem. Pothos has an Iris based concurrent separation logic for interaction trees. We address the problem in a non-extensible setting, with mutable state, non-termination and concur- rency as our chosen effects. Pothos inherits all the executable properties from interaction trees and includes a novel relation of Iris’s step-index with coinductive types. We have proven our logic to be sound and include a case study of a spin lock library. The case study shows that our logic is both non-trivial and can utilize the standard Iris patterns for concurrency.Computer Scienc
Adapting cultural heritage to climate change impacts in the Netherlands: barriers, interdependencies, and strategies for overcoming them
No full textClimate change is currently impacting cultural heritage globally. Despite advances in the understanding of the relationship between climate change impacts and cultural heritage, there are significant barriers that hamper adaptation of cultural heritage to current and projected climate risks. This paper aims to advance the empirical understanding of barriers to adapting cultural heritage to climate-related impacts in the Netherlands by identifying different barriers, their interdependencies, and possible strategies to overcome these barriers. Using a web-based questionnaire with 57 experts, we find that the most frequently reported barriers are a lack of climate change adaptation policy for cultural heritage, and lack of climate vulnerability and risk assessments for diverse cultural heritage types. Our study finds that barriers are perceived to be interdependent and conjointly constrain adapting cultural heritage to climate change. Six actionable strategies are identified to navigate these barriers.History, Form & Aesthetic
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