DIMENSIONALITY REDUCTION METHODS FOR BIOMEDICAL DATA

The aim of this paper is to present basic principles of common multivariate statistical approaches to dimensionality reduction and to discuss three particular approaches, namely feature extraction, (prior) variable selection, and sparse variable selection. Their important examples are also presented in the paper, which includes the principal component analysis, minimum redundancy maximum relevance variable selection, and nearest shrunken centroid classifier with an intrinsic variable selection. Each of the three methods is illustrated on a real dataset with a biomedical motivation, including a biometric identification based on keystroke dynamics or a study of metabolomic profiles. Advantages and benefits of performing dimensionality reduction of multivariate data are discussed

IT Security in Biomedicine.

Název práce: Bezpečnost IT v biomedicíně Autor: Ing. Anna Schlenker Školitel: Ing. Milan Šárek, CSc. Abstrakt: Cílem disertační práce je navrhnout řešení strategie zabezpečení biomedicínských dat. Práce poskytuje přehled nejčastěji používaných biometrických metod určených k identifikaci či autentizaci uživatelů. Z těchto metod byla vybrána a v aplikačním řešení použita metoda dynamiky stisku počítačových kláves. Spolehlivost této metody byla testována klasickými a moderními klasifikačními metodami. Největším přínosem práce je pak použití vytvořené aplikace v kombinaci s měřením pomocí integrované elektromyografie pro objektivizaci hodnocení prací spojených s psaním na klávesnici z hlediska lokální svalové zátěže. Klíčová slova: biometrie, bezpečnost dat, dynamika stisku počítačových kláves, lokální svalová zátěžTitle: IT Security in Biomedicine Author: Ing. Anna Schlenker Supervisor: Ing. Milan Šárek, CSc. Abstract: The aim of this work is to propose a solution to the biomedical data security strategy. The work provides an overview of the most commonly used biometric methods designed to identify or authenticate users. From these methods, the keystroke dynamics was chosen and used in the application solution. The reliability of this method has been tested by classical and modern classification methods. The greatest benefit of the work is the use of the created application in combination with the measurement using integrated electromyography to objectify the evaluation of the work related to keyboard typing in terms of local muscle load. Keywords: Biometrics, Data Security, Keystroke Dynamics, Local Muscle Loadnezařazení_neaktivní1. lékařská fakultaFirst Faculty of Medicin

Air quality and error quantity: pollution and performance in a high-skilled, quality-focused occupation

We provide the first evidence that short-term exposure to air pollution affects the work performance of a group of highly-skilled, quality-focused employees. We repeatedly observe the decision-making of individual professional baseball umpires, quasi-randomly assigned to varying air quality across time and space. Unique characteristics of this setting combined with high-frequency data disentangle effects of multiple pollutants and identify previously under-explored acute effects. We find a 1 ppm increase in 3-hour CO causes an 11.5% increase in the propensity of umpires to make incorrect calls and a 10 mg/m3 increase in 12-hour PM2.5 causes a 2.6% increase. We control carefully for a variety of potential confounders and results are supported by robustness and falsification checks

The personal norm of reciprocity

Reciprocity is here considered as an internalized social norm, and a questionnaire to measure individual differences in the internalized norm of reciprocity is presented. The questionnaire, Personal Norm of Reciprocity (PNR), measures three aspects of reciprocity: positive reciprocity, negative reciprocity, and beliefs in reciprocity. The PNR has been developed and tested in two cultures, British and Italian, for a total of 951 participants. A cross-cultural study provides evidence of good psychometric properties and generalizability of the PNR. Data provide evidence for criterion validity and show that positive and negative reciprocators behave in different ways as a function of the valence (positive or negative) of the other's past behaviour, the type of feasible reaction (reward versus punishment), and the fairness of their reaction. Copyright (C) 2002 John Wiley Sons, Ltd

Disk displacement, eccentric condylar position, osteoarthrosis – misnomers for variations of normality? Results and interpretations from an MRI study in two age cohorts

Background: Clinical decision-making and prognostic statements in individuals with manifest or suspected temporomandibular disorders (TMDs) may involve assessment of (a) the position of articular disc relative to the mandibular condyle, (b) the location of the condyle relative to the temporal joint surfaces, and (c) the depth of the glenoid fossa of the temporomandibular joints (TMJs). The aim of this study was twofold: (1) Determination of the prevalence of these variables in two representative population-based birth cohorts. (2) Reinterpretation of the clinical significance of the findings. Methods: From existing magnetic resonance imaging (MRI) scans of the TMJs that had been taken in 2005 and 2006 from 72 subjects born between 1930 and 1932 and between 1950 and 1952, respectively, the condylar position at closed jaw was calculated as percentage displacement of the condyle from absolute centricity. By using the criteria introduced by Orsini et al. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 86:489-97, 1998), a textbook-like disc position at closed jaw was distinguished from an anterior location. TMJ morphology of the temporal joint surfaces was assessed at open jaw by measuring the depth of the glenoid fossa, using the method proposed by Muto et al. (J Oral Maxillofac Surg 52:1269-72, 1994). Frequency distributions were recorded for the condylar and disc positions at closed jaw. Student’s t-test with independent samples was used as test of significance to detect differences of condylar positions between the age cohorts (1930 vs. 1950) and the sexes. The significance levels were set at 5%. First, the results from the measurement of the age cohorts were compared without differentiation of sexes, i.e., age cohort 1930–1932 versus age cohort 1950–1952. Subsequently, the age cohorts were compared by sex, i.e., men in cohort 1930–1932 versus men in cohort 1950–1952, and women in cohort 1930–1932 women men in cohort 1950–1952. Results: In both cohorts, condylar position was characterized by great variability. About 50% of the condyles were located centrically, while the other half was either in an anterior or in a posterior position. In both female cohorts, a posterior position predominated, whereas a centric position prevailed among men. Around 75% of the discs were positioned textbook-like, while the remaining forth was located anteriorly. Age had no statistically significant influence on condylar or on disc position. Conversely, comparison between the age groups revealed a statistically significant decrease of the depth of the glenoid fossa in both older cohorts. This age-dependent changes may be interpreted as flattening of the temporal joint surfaces. Conclusions: We call for a re-interpretation of imaging findings because they may insinuate pathology which usually is not present. Instead, anterior or posterior positions of the mandibular condyle as well as an anterior location of the articular disc should be construed as a variation of normalcy. Likewise, flattening of articular surfaces of the TMJs may be considered as normal adaptive responses to increased loading, rather than pathological degenerative changes. Trial registration: Not applicable

Reconstruction of primary vertices at the ATLAS experiment in Run 1 proton–proton collisions at the LHC

This paper presents the method and performance of primary vertex reconstruction in proton–proton collision data recorded by the ATLAS experiment during Run 1 of the LHC. The studies presented focus on data taken during 2012 at a centre-of-mass energy of √s=8 TeV. The performance has been measured as a function of the number of interactions per bunch crossing over a wide range, from one to seventy. The measurement of the position and size of the luminous region and its use as a constraint to improve the primary vertex resolution are discussed. A longitudinal vertex position resolution of about 30μm is achieved for events with high multiplicity of reconstructed tracks. The transverse position resolution is better than 20μm and is dominated by the precision on the size of the luminous region. An analytical model is proposed to describe the primary vertex reconstruction efficiency as a function of the number of interactions per bunch crossing and of the longitudinal size of the luminous region. Agreement between the data and the predictions of this model is better than 3% up to seventy interactions per bunch crossing

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

Reimagining Digital Well-Being. Report for Designers & Policymakers

This report aims to offer insights into cutting-edge research on digital well-being. Many of these insights come from a 2-day academic-impact event, The Future of Digital Well-Being, hosted by a team of researchers working with the Royal Netherlands Academy of Arts and Sciences (KNAW) in February 2024. Today, achieving and maintaining well-being in the face of online technologies is a multifaceted challenge that we believe requires using theoretical resources of different research disciplines. This report explores diverse perspectives on how digital well-being can be actively cultivated, while also emphasising the importance of considering individual differences, societal contexts, and nuanced cultural factors. We aim to offer a holistic view of the future of digital well-being, one that will inspire the next generation of designers of online tools, as well as policymakers who will regulate these tools. We start by asking what digital well-being is – how we can best define a concept that is used by diverse stakeholders and researchers from many disciplines in various ways. To do this, we explore the classic ethical theories of well-being, showing how they can give us insights into how the term digital well-being is currently deployed. We then move to look at the existing strategies that have been proposed to actively cultivate digital well-being, exploring the business models that threaten digital well-being and the relative advantages of the digital and non-digital solutions that are currently proposed. On the one hand, digital tools – such as Apple’s Screen Time and app blockers such as Opal and Forest – integrate seamlessly with the digital lifestyles of users. They also create precise metrics for digital well-being, which facilitates their solutions to reduce screen time. On the other hand, non-digital solutions, including mindfulness practices, digital detoxes, and digital well-being coaching, offer a new set of tools to reconnect individuals to their natural rhythms and help to actively promote offline activities. We then move to discuss diversity and how various groups of users have strikingly different digital well-being needs. Embracing neurodiversity in digital well-being is crucial as it strongly impacts the users’ experience of online technologies. When designing for diversity, organisations and designers alike need to prioritise customization for people with physical disabilities, mitigate harmful content for users with mental well-being conditions, address gender stereotypes and online harassment, and be designed in ways that recognize the very real risks of online technologies. This report closes by examining cultural differences. We believe that non-Western conceptions of well-being offer rich sources for enhancing digital well-being insofar as these traditions can inform and inspire the designers of future online technologies. We focus on East-Asian and South-Asian traditions, although in further work we recognise it would be useful to investigate conceptions of well-being that are influential in the Gulf region, Africa, and South America. Each of these areas have ethical frameworks that discuss well-being in depth as well as a rich cultural heritage. In conclusion, this report’s insights underscore the imperative of recognizing diversity in digital well-being, both in terms of cultural contexts and disciplinary perspectives. It emphasises the need for culturally responsive design methodologies and the integration of non-Western philosophical perspectives into current digital well-being research. Embracing this diversity, we believe, offers the best chance to create digital environments that prioritise well-being for users and the societies they live in across the world. Ultimately, we believe that it is not only about designing better online products; it’s about shaping a digital landscape that promotes well-being and flourishing for everyone

Measurement of the total cross section and ρ -parameter from elastic scattering in pp collisions at √s=13 TeV with the ATLAS detector

In a special run of the LHC with β⋆=2.5 km, proton–proton elastic-scattering events were recorded at s√=13 TeV with an integrated luminosity of 340 μb−1 using the ALFA subdetector of ATLAS in 2016. The elastic cross section was measured differentially in the Mandelstam t variable in the range from −t=2.5⋅10−4 GeV2 to −t=0.46 GeV2 using 6.9 million elastic-scattering candidates. This paper presents measurements of the total cross section σtot, parameters of the nuclear slope, and the ρ-parameter defined as the ratio of the real part to the imaginary part of the elastic-scattering amplitude in the limit t→0. These parameters are determined from a fit to the differential elastic cross section using the optical theorem and different parameterizations of the t-dependence. The results for σtot and ρ are σtot(pp→X)=104.7±1.1 mb ,ρ=0.098±0.011. The uncertainty in σtot is dominated by the luminosity measurement, and in ρ by imperfect knowledge of the detector alignment and by modelling of the nuclear amplitude.publishedVersio

Search for a high-mass Higgs boson decaying to a W boson pair in pp collisions at root s=8TeV with the ATLAS detector

A search for a high-mass Higgs boson H is performed in the H -> WW -> l nu l nu and H -> WW -> l nu qq decay channels using pp collision data corresponding to an integrated luminosity of 20.3 fb(-1) collected at root s = 8TeV by the ATLAS detector at the Large Hadron Collider. No evidence of a high-mass Higgs boson is found. Limits on sigma(H) x BR(H -> WW) as a function of the Higgs boson mass m(H) are determined in three different scenarios: one in which the heavy Higgs boson has a narrow width compared to the experimental resolution, one for a width increasing with the boson mass and modeled by the complex-pole scheme following the same behavior as in the Standard Model, and one for intermediate widths. The upper range of the search is m(H) = 1500 GeV for the narrow-width scenario and m(H) = 1000 GeV for the other two scenarios. The lower edge of the search range is 200{300 GeV and depends on the analysis channel and search scenario. For each signal interpretation, individual and combined limits from the two WW decay channels are presented. At m(H) = 1500 GeV, the highest-mass point tested, sigma(H) x BR(H -> WW) for a narrow-width Higgs boson is constrained to be less than 22 fb and 6.6 fb at 95% CL for the gluon fusion and vector-boson fusion production modes, respectively