Visible parts of fractal percolation

We study dimensional properties of visible parts of fractal percolation in the plane. Provided that the dimension of the fractal percolation is at least 1, we show that, conditioned on non-extinction, almost surely all visible parts from lines are 1-dimensional. Furthermore, almost all of them have positive and finite Hausdorff measure. We also verify analogous results for visible parts from points. These results are motivated by an open problem on the dimensions of visible parts.Comment: 22 pages, 3 figure

Porosities and dimensions of measures

We introduce a concept of porosity for measures and study relations between dimensions and porosities for two classes of measures: measures on $R^n$ which satisfy the doubling condition and strongly porous measures on $R$.Comment: Jarvenpaa = J\"arvenp\"a\"

Erityisopettajien käsitykset avoimen oppimisympäristön vaikutuksesta oppilaiden kouluhyvinvointiin

Tiivistelmä. Tässä laadullisessa pro gradu -tutkimuksessa tutkitaan erityisopettajien käsityksiä alakoululaisten kouluhyvinvoinnista. Tutkimuksen tavoitteena oli selvittää erityisopettajien käsityksiä neuropsykiatrisia haasteita omaavien oppilaiden kouluhyvinvoinnista sekä, mitkä tekijät heikentävät tai parantavat kouluhyvinvointia. Tämä tutkimus tuo avoimiin oppimisympäristöihin erityispedagogiikan näkökulmaa. Tutkimuksen teoreettisessa viitekehyksessä tarkastellaan oppimisympäristöä, kouluhyvinvointia ja neuropsykiatrisia häiriöitä aikaisemman kirjallisuuden pohjalta. Tutkimuskysymyksissä haettiin tekijöitä, jotka joko paransivat tai heikensivät oppilaiden kouluhyvinvointia avoimessa oppimisympäristössä erityisopettajien käsityksen mukaan, kun oppilailla oli neuropsykiatrisia haasteita. Aikaisemman kirjallisuuden mukaan oppimisympäristöllä on suuri merkitys oppilaiden oppimiselle. Hyvä oppimisympäristö ottaa huomioon kaikkien oppilaiden tarpeet ja hyvinvoinnin, tukee oppilaiden oppimista sekä itsetuntoa. Fyysisen oppimisympäristön tulee olla monipuolinen, jossa on erikokoisia tiloja erilaisille oppijoille. Lähdekirjallisuuden mukaan oppimisympäristö voi muun muassa tukea oppilaan ajattelua, toiminnanohjausta ja tarkkaavuuden suuntaamista. Tutkimusaineisto kerättiin haastattelemalla neljää alakoulun laaja-alaista erityisopettajaa, jotka työskentelivät avoimessa oppimisympäristössä Pohjois-Suomen alueella. Tutkimuksen lähestymistapa oli fenomenografinen, koska tutkittiin erityisopettajien käsityksiä. Aineisto analysoitiin aineistolähtöisellä sisällönanalyysillä. Tutkimustulosten mukaan kouluhyvinvointia parantaa yhteisopettajuus, oma paikka ja rauhoittumispaikka. Kouluhyvinvointia heikentää äänihaitat, oman paikan puuttuminen ja rauhattomuus. Tutkimuksen tulosten mukaan erityisopettajat olivat pääasiassa tyytyväisiä avoimiin oppimisympäristöihin, mutta tiloihin toivottiin lisää jakotiloja. Jakotilat koettiin kouluhyvinvointia tukevina ratkaisuina. Tutkimuksen tulokset ovat osittain yhteneviä aikaisempien tutkimusten kanssa

Slicing Sets and Measures, and the Dimension of Exceptional Parameters

We consider the problem of slicing a compact metric space \Omega with sets of the form \pi_{\lambda}^{-1}\{t\}, where the mappings \pi_{\lambda} \colon \Omega \to \R, \lambda \in \R, are \emph{generalized projections}, introduced by Yuval Peres and Wilhelm Schlag in 2000. The basic question is: assuming that \Omega has Hausdorff dimension strictly greater than one, what is the dimension of the 'typical' slice \pi_{\lambda}^{-1}{t}, as the parameters \lambda and t vary. In the special case of the mappings \pi_{\lambda} being orthogonal projections restricted to a compact set \Omega \subset \R^{2}, the problem dates back to a 1954 paper by Marstrand: he proved that for almost every \lambda there exist positively many $t \in \R$ such that \dim \pi_{\lambda}^{-1}{t} = \dim \Omega - 1. For generalized projections, the same result was obtained 50 years later by J\"arvenp\"a\"a, J\"arvenp\"a\"a and Niemel\"a. In this paper, we improve the previously existing estimates by replacing the phrase 'almost all \lambda' with a sharp bound for the dimension of the exceptional parameters.Comment: 31 pages, three figures; several typos corrected and large parts of the third section rewritten in v3; to appear in J. Geom. Ana

Reliability and validity of the Finnish version of the Lower Extremity Functional Scale (LEFS)

cited By 0; Article in PressPeer reviewe

Neonatal Nutrition Predicts Energy Balance in Young Adults Born Preterm at Very Low Birth Weight

Epidemiological studies and animal models suggest that early postnatal nutrition and growth can influence adult health. However, few human studies have objective recordings of early nutrient intake. We studied whether nutrient intake and growth during the first 9 weeks after preterm birth with very low birth weight (VLBW,Peer reviewe

Reliability and validity of the Finnish version of the Visual Analogue Scale Foot and Ankle (VAS-FA)

Background: There have previously been no validated foot and ankle-specific patient-reported outcome measures in Finnish. Methods: The Visual Analogue Scale Foot and Ankle (VAS-FA) was translated and adapted into Finnish. Thereafter, 165 patients who had undergone foot and ankle surgery completed a questionnaire set on two separate occasions. Analyses included testing of floor-ceiling effect, internal consistency, reproducibility, and validity. Results: Minor linguistic differences emerged during the translation. Some structural adjustments were made. The mean (SD) total VAS-FA score was 74 (23). In the three subscales, maximum scores were noted in 2-5% of the responses, and internal consistency ranged from 0.81 to 0.94. Reproducibility was excellent (ICC, 0.97). The total VAS-FA score correlated significantly with the Lower Extremity Functional Scale (r = 0.84) and the 15D Mobility dimension (r = 0.79). The VAS-FA loaded on two factors (pain/movement and problems/limitations). Conclusions: The Finnish version of the VAS-FA has high reliability and strong validity. (C) 2017 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.Peer reviewe

Sinonasal inverted papilloma - malignant transformation and non-sinonasal malignancies

Objectives: To assess malignant transformation rate, non-sinonasal malignancies, and factors contributing to recurrence in patients treated for sinonasal inverted papilloma (SNIP).Study design: Retrospective study.Methods: We retrospectively reviewed medical records of all patients treated for SNIP (n = 296) between the years 1984-2014 at Helsinki University Hospital. Data from the Finnish Cancer Registry confirmed the number of those patients with sinonasal and non-sinonasal malignancies.Results: Only 2 of 296 (0.7%) patients primarily diagnosed with benign SNIP developed sinonasal cancer in a mean follow-up of 5.8 years. The most common non-sinonasal cancer sites were similar to those reported for the whole Finnish population. None of the patients presented with an HPV-associated non-sinonasal malignancy. The recurrence rate among patients who underwent attachment-oriented surgery was significantly lower compared to those operated on with other approaches (40.2% vs. 56.6%, p = 0.006). Dysplasia in SNIP was associated with a higher recurrence rate (p Conclusions: Malignant transformation of SNIP was rare. Patients with SNIP were not prone to HPV-associated non-sinonasal malignancies. Endoscopic resection and attachment-oriented surgery have become predominant approaches in the treatment of SNIP; meanwhile, the total number of SNIP recurrences has decreased.</p

Asbestos-related pleural and lung fibrosis in patients with retroperitoneal fibrosis

<p>Abstract</p> <p>Background</p> <p>Retroperitoneal fibrosis (RPF) is a rare fibroinflammatory disease that leads to hydronephrosis and renal failure. In a case-control study, we have recently shown that asbestos exposure was the most important risk factor for RPF in the Finnish population. The aim of this study was to evaluate the relation of asbestos exposure to radiologically confirmed lung and pleural fibrosis among patients with RPF.</p> <p>Methods</p> <p>Chest high-resolution computed tomography (HRCT) was performed on 16 unexposed and 22 asbestos-exposed RPF patients and 18 asbestos-exposed controls. Parietal pleural plaques (PPP), diffuse pleural thickening (DPT) and parenchymal fibrosis were scored separately.</p> <p>Results</p> <p>Most of the asbestos-exposed RPF patients and half of the asbestos-exposed controls had bilateral PPP, but only a few had lung fibrosis. Minor bilateral plaques were detected in two of the unexposed RPF patients, and none had lung fibrosis. DPT was most frequent and thickest in the asbestos-exposed RPF-patients. In three asbestos-exposed patients with RPF we observed exceptionally large pleural masses that were located anteriorly in the pleural space and continued into the anterior mediastinum.</p> <p>Asbestos exposure was associated with DPT in comparisons between RPF patients and controls (case-control analysis) as well as among RPF patients (case-case analysis).</p> <p>Conclusion</p> <p>The most distinctive feature of the asbestos-exposed RPF patients was a thick DPT. An asbestos-related pleural finding was common in the asbestos-exposed RPF patients, but only a few of these patients had parenchymal lung fibrosis. RPF without asbestos exposure was not associated with pleural or lung fibrosis. The findings suggest a shared etiology for RPF and pleural fibrosis and furthermore possibly a similar pathogenetic mechanisms.</p