Search results for "reaktiivisuus"
showing 10 items of 15 documents
Effect of Foreperiod Duration and Handedness on Simple and Choice Auditory Reaction Time Among the Older People
2017
Objectives Cognitive functions such as reaction time undergo change with aging. Given the importance of preparation in response to reaction time in various life situations, this study aimed to examine the effect of various foreperiods (0.5, 1.5, 2.5, and 3.5 s), and handedness at the time of simple and choice auditory reaction time. Methods & Materials The current research followed a quasi-experimental methodology and was carried out using a self-made software. The study population comprised all old people living in Ahvaz City. Of them, 30 people were selected through purposive sampling method and allocated into two groups of right- and left-handed people. Each individual was randomly teste…
Comparison of body segment models for female high jumpers utilising DXA images
2022
In motion analysis of sport competitions, the question is often about the most convenient choice for defining the segment endpoints when no visible landmarks can be used. The purpose of the present study was to determine the location of the body centre of mass (CoM) of female high jumpers by using a high accuracy reaction board and two different segment models: Dempster, 1955, de Leva, 1996. Digitising the bony landmarks from the images of dual energy x-ray absorptiometry (DXA) and overhead digital camera were used to compare the digitising accuracy. The location of the CoM determined by a reaction board was 55.88 ± 0.52 % of subjects’ body height. The segment model of Dempster digitized fr…
Measuring Public Speaking Anxiety: Self-report, behavioral, and physiological
2021
Self-reports are typically used to assess public speaking anxiety. In this study, we examined whether self-report, observer report, and behavioral and physiological reactivity were associated with each other during a speech challenge task. A total of 95 university students completed a self-report measure of public speaking anxiety before and after the speech challenge. Speech duration (i.e., behavioral measure), physiological reactivity, as well as speech performance evaluated by the participants and observers were also recorded. The results suggest that self-reported public speaking anxiety predicts speech duration, as well as speech quality, as rated by the participants themselves and ob…
Surface Coordination of Multiple Ligands Endows N‐Heterocyclic Carbene‐Stabilized Gold Nanoclusters with High Robustness and Surface Reactivity
2020
Deciphering the molecular pictures of the multi-component and non-periodic organic-inorganic interlayer is a grand technical challenge. Here we show that the atomic arrangement of hybrid surface ligands on metal nanoparticles can be precisely quantified through comprehensive characterization of a novel gold cluster, Au 44 ( i Pr 2 -bimy) 9 (PA) 6 Br 8 , which features three types of ligands, namely, carbene (1,3-diisopropylbenzimidazolin-2-ylidene, i Pr 2 -bimy), alkynyl (phenylacetylide, PA), and halide (Br), respectively. The delicately balanced stereochemical effects and bonding capabilities of the three ligands give rise to peculiar geometrical and electronic structures. Remarkably, des…
The Aluminyl Anion : A New Generation of Aluminium Nucleophile
2020
Trivalent aluminium compounds are well known for their reactivity as Lewis acids/electrophiles, a feature that is exploited in many pharmaceutical, industrial and laboratory-based reactions. Recently, a series of isolable aluminium(I) anions ('aluminyls') have been reported, which offer an alternative to this textbook description: these reagents behave as aluminium nucleophiles. This minireview covers the synthesis, structure and reactivity of aluminyl species reported to date, together with their associated metal complexes. The frontier orbitals of each of these species have been investigated using a common methodology to allow for a like-for-like comparison of their electronic structure a…
Suorituskyvyn parantaminen reaktiivisella funktio-ohjelmoinnilla tehdyissä peleissä
2017
Tämän pro gradu -tutkielman tavoitteena on tutkia, miten suorituskykyä voi parantaa reaktiivisella funktio-ohjelmoinnilla tehdyissä peleissä. Tutkielmassa tuotettiin suunnittelutieteen menetelmien mukaisesti IT-artefakti, jolla pystyy rinnakkaistamaan peliobjektien päivityksen reaktiivisella funktio-ohjelmoinnilla tehdyissä peleissä. Suorituskykymittausten perusteella IT-artefakti paransi mittauksessa käytetyn testipelin suorituskykyä. Improving performance in games made with functional reactive programming. The purpose of this master’s thesis is to study how performance can be improved in games made with reactive functional programming. Design science method was used to create an IT artifa…
Miten tiede on vastannut yhteiskunnallisiin haasteisiin?
2023
Suomen Akatemia järjesti sidosryhmilleen ”Tiede ja tutkimus tulevaisuuden menestystekijöinä: Tieteen tila” -tilaisuuden Helsingissä 14.10.2022. Tilaisuuteen kutsuttua kahta tutkijaa pyydettiin pohtimaan puheessaan oman alansa näkökulmasta, miten tiede on vastannut yhteiskunnallisiin haasteisiin. Tämä teksti on puheeni, jossa pohdin tieteen vaikuttavuutta taiteen ja kulttuurin tutkimuksen näkökulmasta. nonPeerReviewed
Experimental and computational studies of unconventional main group compounds : stable radicals and reactive intermediates
2017
Ever since their discovery, radicals have intrigued the minds of experimental and theoretical chemists alike. While the vast majority of radicals are transient species, a large number of stable and persistent radicals are also known. This has enabled the use of radicals in different applications. For example, radicals are highly useful in chemical synthesis due to their selectivity and functional group tolerance. Detailed knowledge of the electronic structure of synthetic intermediates, both radical and non-radical, enables chemists to improve existing synthesis routes and to design completely new ones. This thesis is divided into two parts. The first part begins with an introduction to the…
Transkraniaalisen tasavirtastimulaation vaikutukset erottelu- ja käänteisoppimiseen sekä reagointiherkkyyden muutoksiin
2017
Transkraniaalisella tasavirtastimulaatiolla (tDCS) tarkoitetaan menetelmää, jossa johdetaan heikkoa sähkövirtaa aivokudosten läpi elektrodilta toiselle. Tutkimusten mukaan tDCS:lla näyttäisi olevan monenlaisia kliinisiä ja kognitiivisia vaikutuksia aina masennuksen hoidosta työmuistin parantamiseen. Tulokset ovat kuitenkin monin paikoin varsin ristiriitaisia, eikä stimulaation tarkoista vaikutusmekanismeistakaan olla päästy varmuuteen. Tässä tutkimuksessa halusimme tutkia kokeellisesti tDCS:n vaikutuksia erottelu- ja käänteisoppimiseen sekä reagointiherkkyyden muutoksiin silmäniskuehdollistumisen avulla. Kokeeseen osallistui 39 iältään 18-29-vuotiasta koehenkilöä. Tutkittavat jaettiin kahte…
Sunlit surface waters : exploring the photochemical reactivity of dissolved organic carbon
2017
In surface waters, solar radiation can photochemically mineralise the dissolved organic carbon (DOC, a measure of dissolved organic matter, DOM) to dissolved inorganic carbon (DIC). This DIC photoproduction constitutes an essential yet vague flux in the aquatic carbon cycling. The present thesis is based on the empirical assessment of the DOC photochemical reactivity, which was determined as the spectral apparent quantum yields (AQY) for DIC photoproduction. First, AQYs were determined in DOM solutions to quantify the impact of pH and DOM-associated iron. Then boreal lake waters were used for assessing the alteration of DOC photoreactivity due to water quality and catchment property. By sim…