848 research outputs found
Spatial contrast sensitivity and external noise: applications to optical and neural modulation transfer functions
The thesis will show how to equalise the effect of quantal noise across spatial frequencies by keeping the retinal flux (If-2) constant. In addition, quantal noise is used to study the effect of grating area and spatial frequency on contrast sensitivity resulting in the extension of the new contrast detection model describing the human contrast detection system as a simple image processor. According to the model the human contrast detection system comprises low-pass filtering due to ocular optics, addition of light dependent noise at the event of quantal absorption, high-pass filtering due to the neural visual pathways, addition of internal neural noise, after which detection takes place by a local matched filter, whose sampling efficiency decreases as grating area is increased. Furthermore, this work will demonstrate how to extract both the optical and neural modulation transfer functions of the human eye. The neural transfer function is found to be proportional to spatial frequency up to the local cut-off frequency at eccentricities of 0 - 37 deg across the visual field. The optical transfer function of the human eye is proposed to be more affected by the Stiles-Crawford -effect than generally assumed in the literature. Similarly, this work questions the prevailing ideas about the factors limiting peripheral vision by showing that peripheral optical acts as a low-pass filter in normal viewing conditions, and therefore the effect of peripheral optics is worse than generally assumed
Oululaisten lastentarhanopettajien kokemuksia katsomuskasvatukseen liittyvistÀ muutoksista
TiivistelmÀ. TÀmÀn pro gradu -tutkielman tavoitteena on selvittÀÀ ja kuvata lastentarhanopettajien kokemuksia varhaiskasvatuksen katsomuskasvatuksesta ja siihen liittyvistÀ muutoksista. Tutkielmassa avataan sitÀ, millainen muutos on ollut oululaisten lastentarhanopettajien kuvaamina. Uudet Varhaiskasvatussuunnitelman perusteet (2016) tulivat velvoittavaksi elokuussa 2017. SiinÀ yhteydessÀ varhaiskasvatuksen uskonnollisesta kasvatuksesta alettiin kÀyttÀÀ termiÀ katsomuskasvatus, aiemman uskonnollis-katsomuksellisen orientaation sijaan. Katsomuskasvatuksessa tavoitteena on tutustua lapsiryhmÀssÀ lÀsnÀoleviin katsomuksiin ja niiden perinteisiin (Varhaiskasvatussuunnitelman perusteet 2016, 43).
Laadullisen tutkielman aineiston muodostaa lastentarhanopettajien vastaukset (N=21), jotka kerÀttiin sÀhköisellÀ kyselylomakkeella marraskuussa 2017. Aineisto koostuu avointen kysymysten vastauksista, joissa vastaajat kuvasivat kokemuksiaan tutkittavasta aiheesta. Tutkielma perustuu fenomenologis-hermeneuttiseen tieteenfilosofiaan. SiinÀ tavoitteena on ymmÀrtÀÀ vastaajien kokemuksia ja syventÀÀ tutkimusilmiöön liittyvÀÀ ymmÀrrystÀ. AnalyysissÀ hyödynsin laadullisen analyysin spiraalia (PeltomÀki 2014), joka kuvastaa ymmÀrryksen spiraalimaista syvenemistÀ.
Tutkielman tuloksista oli havaittavissa, ettÀ katsomuskasvatuksen toteutusmuodot hakivat vielÀ muotoaan aineistonkeruuhetkellÀ. Tulosten perusteella ei voi sanoa, ettÀ katsomuskasvatus olisi ollut Varhaiskasvatussuunnitelman perusteiden (2016) tavoitteiden mukaista. Suurimmat muutokset koskivat seurakuntayhteistyötÀ. Vastaajat pohtivat aihetta useista eri nÀkökulmista. Pohdinnoissa korostui erityisesti uskonnon ja kulttuurin vÀlinen suhde. LisÀksi he pohtivat aihetta lasten taustojen nÀkökulmasta. LapsiryhmÀn katsomukselliset taustat vaikuttivat siihen, miten he kuvasivat uskonnollisen kasvatuksen kÀytÀntöjÀ. TÀrkeÀnÀ nÀkökulmana nousi myös esiin heidÀn omat valmiutensa katsomuskasvatuksen toteuttamiseen. Useimmat kokivat, ettÀ heillÀ ei ole siihen riittÀvÀsti tietotaitoa.
Tutkielman perusteella voidaan pÀÀtellĂ€, ettĂ€ katsomuskasvatukselle asetettujen tavoitteiden saavuttamiseksi oli vielĂ€ paljon tehtĂ€vÀÀ. YhtenĂ€isistĂ€ ohjeista huolimatta kĂ€ytĂ€nteet vaihtelivat. ĂĂ€rimmilleen vietynĂ€ toiminnasta oli karsittu kaikki uskontoihin ja katsomuksiin liittyvĂ€t elementit
PitkÀt yhtÀjaksoiset yksilöterapiat : Terapioiden merkitys kuntoutujan ja kuntoutuksen eri toimijoiden nÀkökulmista
TĂ€ssĂ€ tutkimuksessa selvitettiin kuntoutumisen merkityksiĂ€ pitkÀÀn yhtĂ€jaksoisesti avomuotoista yksilöterapiaa saaneille kuntoutujille ja kuntoutuksen toteutumista kuntoutujan, palveluntuottajan ja hoitavan tahon nĂ€kökulmasta. Tutkimus on osa Kelan PitkĂ€t yhtĂ€jaksoiset yksilöterapiat -tutkimusta. Tutkimuksen kohderyhmĂ€ olivat vuoden 2015 Kelan kuntoutustietojen mukaan avomuotoista fysio-, musiikki-, puhe- ja toimintaterapiaa sekĂ€ neuropsykologista kuntoutusta yhtĂ€jaksoisesti yli 5 vuotta saaneet kuntoutujat. Tutkimukseen osallistui 30 kuntoutujaa (8â64 vuotta), 30 terapeuttia ja 6 lÀÀkĂ€riĂ€. Aineisto kerĂ€ttiin teemahaastatteluilla, jotka nauhoitettiin ja litteroitiin. Haastattelujen lisĂ€ksi laadullisen sisĂ€llönanalyysin aineistona olivat kuntoutussuunnitelmat, -palautteet ja -pÀÀtökset. Kaikki haastatellut kokivat avokuntoutuksen hyödylliseksi, terapian jatkumiselle löytyi perusteita ja kaikki olivat edistyneet tai heidĂ€n toimintakykynsĂ€ oli pysynyt ennallaan viimeisimmĂ€nkin terapiavuoden aikana. PitkÀÀn jatkuneen avokuntoutuksen merkitys haastatelluille kuntoutujille rakentuu laaja-alaisista hyödyistĂ€ kuntoutujan arkeen, osallistumiseen ja elĂ€mĂ€nlaatuun. Aineistossa toistuu hyvin toimivan kuntoutuksen moninainen hyöty myös yhteiskunnalle. TĂ€mĂ€n tutkimuksen perusteella pitkiĂ€ yhtĂ€jaksoisia yksilöterapioita tulisi kehittÀÀ hyödyntĂ€mĂ€llĂ€ toimintakyvyn arviointimenetelmiĂ€, nĂ€yttöön perustuvaa toimintaa ja suosituksia sekĂ€ kuntoutuspalautteiden kirjaamista niin, ettĂ€ palautteissa tulisi selkeĂ€mmin esille niin kuntoutujan toimintakyvyn, tavoitteiden kuin terapian toteutuksenkin muutokset. Haastattelut tehtiin kevÀÀllĂ€ 2016, jolloin uusi laki Kelan vaativasta kuntoutuksesta oli juuri tullut voimaan. Tutkimusaineisto kuvaa vanhan lain ja Kelan standardien mukaan toteutettua pitkÀÀ vaikeavammaisten avokuntoutusta, eikĂ€ tuloksista voi tehdĂ€ johtopÀÀtöksiĂ€ uuden vaativan lÀÀkinnĂ€llisen kuntoutuksen lain mukaisesta tai mÀÀrittĂ€mĂ€stĂ€ kuntoutuksen toteutuksesta.peerReviewedVertaisarvioit
Severity Biomarkers in Puumala Hantavirus Infection
Annually, over 10,000 cases of hemorrhagic fever with renal syndrome (HFRS) are diagnosed in Europe. Puumala hantavirus (PUUV) causes most of the European HFRS cases. PUUV causes usually a relatively mild disease, which is rarely fatal. However, the severity of the infection varies greatly, and factors affecting the severity are mostly unrevealed. Host genes are known to have an effect. The typical clinical features in PUUV infection include acute kidney injury, thrombocytopenia, and increased vascular permeability. The primary target of hantavirus is the endothelium of the vessels of different organs. Although PUUV does not cause direct cytopathology of the endothelial cells, remarkable changes in both the barrier function of the endothelium and the function of the infected endothelial cells occur. Host immune or inflammatory mechanisms are probably important in the development of the capillary leakage. Several immunoinflammatory biomarkers have been studied in the context of assessing the severity of HFRS caused by PUUV. Most of them are not used in clinical practice, but the increasing knowledge about the biomarkers has elucidated the pathogenesis of PUUV infection.Peer reviewe
Prevention of leg cramps by using compression stockings or magnesium supplements in the 50-84 age group : study protocol for a randomised controlled trial
Background: Leg cramps are painful sensations of tightening in the muscles of the legs that commonly appear during the night and are often associated with secondary insomnia. They are common especially in older age. There is no evidence that any method of prevention of nocturnal leg cramps is both safe and effective. There are no previous trials concerning cramp prevention by using compression stockings. The objective of this study is to assess in a prospective randomised controlled trial whether leg cramps can be prevented by the daily use of knee-length compression stockings or magnesium supplements. Methods: The study will be set in Finland, and 50-84-year-old volunteers will be recruited through Google Ads, the Finnish health library website and Finnish primary health care centres. The participants must have a minimum of two episodes of leg cramps per week for the past 4 weeks to be included in the study. The participants (n = 225) will be allocated to three equal groups: the compression stocking arm, the magnesium supplement arm and the placebo arm. The participants will go through 4 weeks of follow-up without intervention and then another 4 weeks of follow-up with the assigned intervention. The material for the study will be collected through electronic questionnaires. Discussion: This protocol describes a study that compares compression stockings, magnesium supplements and placebo for the prevention of leg cramps. The results of this study can significantly improve knowledge on the methods of preventing leg cramps.Peer reviewe
Temporal genetic structure in a poecilogonous polychaete: the interplay of developmental mode and environmental stochasticity
Background: Temporal variation in the genetic structure of populations can be caused by multiple factors, including natural selection, stochastic environmental variation, migration, or genetic drift. In benthic marine species, the developmental mode of larvae may indicate a possibility for temporal genetic variation: species with dispersive planktonic larvae are expected to be more likely to show temporal genetic variation than species with benthic or brooded non-dispersive larvae, due to differences in larval mortality and dispersal ability. We examined temporal genetic structure in populations of Pygospio elegans, a poecilogonous polychaete with within-species variation in developmental mode. P. elegans produces either planktonic, benthic, or intermediate larvae, varying both among and within populations, providing a within-species test of the generality of a relationship between temporal genetic variation and larval developmental mode. Results: In contrast to our expectations, our microsatellite analyses of P. elegans revealed temporal genetic stability in the UK population with planktonic larvae, whereas there was variation indicative of drift in temporal samples of the populations from the Baltic Sea, which have predominantly benthic and intermediate larvae. We also detected temporal variation in relatedness within these populations. A large temporal shift in genetic structure was detected in a population from the Netherlands, having multiple developmental modes. This shift could have been caused by local extiction due to extreme environmental conditions and (re)colonization by planktonic larvae from neighboring populations. Conclusions: In our study of P. elegans, temporal genetic variation appears to be due to not only larval developmental mode, but also the stochastic environment of adults. Large temporal genetic shifts may be more likely in marine intertidal habitats (e.g. North Sea and Wadden Sea) which are more prone to environmental stochasticity than the sub-tidal Baltic habitats. Sub-tidal and/or brackish (less saline) habitats may support smaller P. elegans populations and these may be more susceptible to the effects of random genetic drift. Moreover, higher frequencies of asexual reproduction and the benthic larval developmental mode in these populations leads to higher relatedness and contributes to drift. Our results indicate that a general relationship between larval developmental mode and temporal genetic variation may not exist
Predictors of osteoarthritis following operative treatment of medial tibial plateau fractures
Purpose: To determine factors influencing the development of posttraumatic osteoarthritis (OA) following medial tibial plateau fractures and to evaluate concomitant injuries associated with these fractures. Materials and methods: A chart review of patients with operatively treated medial tibial plateau fractures admitted to our Level I trauma centre from 2002 to 2008 was performed. Of 63 patients, 41 participated in a clinical and radiographic examination. The mean age was 47 years (range 16-78) and the mean follow-up time was 7.6 (range 4.7-11.7) years. All patients had preoperative computed tomography (CT) scans and postoperative radiographs. At the end of follow-up, standing radiographs, mechanical axis, and CT scans were evaluated. Results: Of the 41 patients, 24 had no or mild (Kellgren-Lawrence grade 0-2) OA and 17 had severe (grade 3-4) OA. Initial articular depression measured from preoperative CT scans was a significant predictor of OA (median 1.8 mm vs 4.5 mm, p = 0.009). Fracture line extension to the lateral plateau (p = 0.68) or fracture comminution (p = 0.21) had no effect on the development of posttraumatic OA, nor did articular depression at the end of follow-up (p = 0.68) measured from CT scans. Mechanical axis >4 degrees of varus and >= 2 mm articular depression or step-off were associated with worse WOMAC pain scores, but did not affect other functional outcome scores. Six patients (10%) had permanent peroneal nerve dysfunction. Ten patients (16%) required LCL reconstruction and nine (14%) ACL avulsions were treated at the time of fracture stabilisation. Conclusions: The amount of articular depression measured from preoperative CT scans seems to predict the development of posttraumatic OA, probably reflecting the severity of chondral injury at the time of fracture. Restoration of mechanical axis and articular congruence are important in achieving a good clinical outcome. (C) 2017 Elsevier Ltd. All rights reserved.Peer reviewe
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