1,567 research outputs found
Characterization of preclones by matrix collections
Preclones are described as the closed classes of the Galois connection
induced by a preservation relation between operations and matrix collections.
The Galois closed classes of matrix collections are also described by explicit
closure conditions.Comment: 11 page
Closed classes of functions, generalized constraints and clusters
Classes of functions of several variables on arbitrary non-empty domains that
are closed under permutation of variables and addition of dummy variables are
characterized in terms of generalized constraints, and hereby Hellerstein's
Galois theory of functions and generalized constraints is extended to infinite
domains. Furthermore, classes of operations on arbitrary non-empty domains that
are closed under permutation of variables, addition of dummy variables and
composition are characterized in terms of clusters, and a Galois connection is
established between operations and clusters.Comment: 21 page
Differential Expression Of Gap Junction mRNAs And Proteins In The Developing Murine Kidney And In Experimentally Induced Nephric Mesenchymes
The expression of three gap junction (GJ) proteins, alpha-1 (Cx43), beta-1 (Cx32), and beta-2 (Cx26), and their transcripts were examined during the ontogeny of the mouse and rat kidney. These proteins were expressed in two non-overlapping patterns. The alpha-1 GJ protein was first observed in mesenchymal cells in the 12-day mouse kidney. By day 14 and thereafter, the ai protein was detected in the transient S-shaped bodies, but not in the podocytes of the maturing glomeruli. After birth the antigen was retained in a small subset of secretory tubules.The beta-1 and beta-2 GJ proteins were similar in their developmental patterns. They were first detected in a small subset of secretory tubules in the subcortical zone of day 17 embryos. These tubules were identified by immunohistochemical markers to be proximal. At birth, practically all proximal tubules expressed the two antigens.This analysis of GJ proteins was consistent with the results of S1 nuclease protection assays showing that, while the alpha-1 mRNA appeared early during kidney development and declined around birth, the two beta mRNAs appeared later and became intensified during the last days of intrauterine development.In experimentally induced metanephric mesenchymes, a transient expression of the alpha-1 GJ protein was seen during the segregation of the tubular anlagen. beta-1 and beta-2 GJ proteins were not detected in such induced mesenchymes cultivated up to 7 days.These observations provide evidence for the cell-specific utilization of different GJ genes during different stages of kidney organogenesis. The alpha-1 gene is activated during the early segregation of the secretory tubule and might contribute to its compartmentalization, while the beta-1 and beta-2 gene products are not detected until advanced stages of development. The latter gene products might be correlated with the physiological activity of the proximal tubules in vivo, as they are not expressed in experimentally induced tubules detectable with markers for proximal tubules
Patient injuries in operative rhinology during a ten-year period : Review of national patient insurance charts
Objectives: To assess factors contributing to patient injuries in operative rhinology. Design: Data of the accepted patient injury claims involving operative rhinology, between the years 2001 and 2011, were obtained from the Finnish Patient Insurance Centre registry. Two senior otolaryngologists analysed and evaluated the injury mechanisms. Main outcome measures: Analysis and classification of factors contributing to patient injuries. Results: During the ten-year study period, there were 67 patient injuries in operative rhinology, comprising 36% of all patient injuries in otorhinolaryngologic surgery. The majority (78%) of patients were treated in university or central hospitals and almost all (90%) by fully trained otolaryngology specialists. The factors contributing to the injuries were errors in surgical technique, like lesions to the orbit, skull base and meninges, and adjacent nerves, as well as mistakes with removable packings left in situ. Nearly half of the patients had undergone endoscopic sinus surgery. One patient died because of bleeding from the intracranial artery. Fourteen patients (21%) needed a re-operation due to the injury. Conclusions: Patient injuries in rhinology were caused by typical complications of common operations performed by otorhinolaryngology specialists. The increased volume of endoscopic sinus surgery was evident also in patient injuries.Peer reviewe
Where do people direct their attention while cycling? : A comparison of adults and children
Cycling in urban environments requires the ability to distinguish between relevant and irrelevant targets quickly and reliably, so that potential hazards can be anticipated and avoided. In two experiments, we investigated where adults and children direct their attention when viewing videos filmed from a cyclist's perspective. We wanted to see if there were any differences in the responses given by experienced adult cyclists, inexperienced adult cyclists, and child cyclists. In Experiment 1,16 adults (19-33 years) were asked to watch ten videos and to point out things they would pay attention to by tapping a touchscreen (pointed out locations). Afterwards, they were asked to explain their answers. In Experiment 2, 17 adults (19-34 years) and 17 children (11-12 years) performed the same task with the same ten videos, but they were not asked to explain their answers afterwards. The data sets from these two experiments were pooled, creating three groups: ten experienced adult cyclists, 23 inexperienced adult cyclists and 17 children. A total of 23 clearly visible, traffic-relevant targets (pre-specified targets) had previously been identified in the videos. We investigated whether the participants' pointed-out locations matched these targets (and if so, how fast they responded in pointing them out). We also investigated the number and vertical/horizontal dispersion of these pointed-out locations on the touchscreen. Adults pointed out more locations than children, especially pedestrians and cyclists. This result suggests that, while children focussed as well as adults on cars (arguably the most salient hazard), they were less able to identify other hazards (such as pedestrians or other cyclists). The children had also a larger vertical dispersion and a larger between-participant variation than the adults. Adults were faster at tapping the pre-specified targets and they missed them less often. Overall, the results suggest that 11-12 year old-cyclists have worse situation awareness in traffic than adults. (C) 2018 Published by Elsevier Ltd.Peer reviewe
Positiivisen psykologian onnellisuus- ja hyvinvointiteoriat ja käytännön sovellukset
Tiivistelmä. Tarkastelen kandidaatintutkielmassani positiivisen psykologian erilaisia onnellisuus- ja hyvinvointiteorioita sekä niiden pohjalta keinoja, joiden avulla yksilö voi lisätä omaa onnellisuuttaan. Onnellisuus on ajankohtainen aihe, sillä lähes kaikki pyrkivät elämässään onnellisuuteen. Tutkimuskysymykseni ovat: "Minkälaisia onnellisuusteorioita psykologiassa on? Miten onnellisuusteoriat mallintavat onnellisuuden ja hyvinvoinnin lisäämistä? Ja millä tavoin yksilö voi lisätä omaa onnellisuuttaan?". Ensin määrittelen positiivisen psykologian, onnellisuuden ja hyvinvoinnin käsitteet. Tämän jälkeen lähden tarkastelemaan onnellisuuden eri teorioita. Etenen tutkielmassani tarkastelemalla positiivisen psykologian tutkimuksia sekä näkökulmia onnellisuudesta. Tämän pohjalta käsittelen kysymystä, minkälaisin keinoin yksilö voi lisätä omaa onnellisuuttaan. Käytän tutkielmassani tutkimusmetodina kirjallisuuskatsausta.
Onnellisuus on positiivisen psykologian yksi suurimmista tutkimuskohteista. Onnellisuuden käsitteelle on silti hankala antaa yhtä tiettyä määritelmää, sillä onnellisuuteen liittyy monenlaisia näkökulmia ja mielipiteitä riippuen ihmisistä ja kulttuureista. Tutkimuksessani onkin tarkoitus saada selvyyttä erilaisiin käsityksiin onnellisuudesta ja sen pohjalta määritellä paremmin, kuinka onnellisuutta pystyy lisäämään.
Tuloksista tulee ilmi, että onnellisuuteen vaikuttavat monenlaiset tekijät. Kaksoistutkimusten perusteella on kehitelty teoria, jonka myötä ajatellaan geenien vaikuttavan onnellisuuteen 50 prosenttia, tietoinen toiminta 40 prosenttia ja olosuhteet vain 10 prosenttia. Tutkielman tuloksissa korostuu ihmissuhteiden tärkeys sekä yksilön oma voima vaikuttaa omaan onnellisuuteensa. Yksilö voi edistää omaa onnellisuuttaan monen eri keinoin. Tärkeimpinä nostetaan esille muun muassa ihmissuhteisiin panostaminen, kiitollisuuden ja optimismin vaaliminen sekä tavoitteiden asettaminen
Large deviations for a damped telegraph process
In this paper we consider a slight generalization of the damped telegraph
process in Di Crescenzo and Martinucci (2010). We prove a large deviation
principle for this process and an asymptotic result for its level crossing
probabilities (as the level goes to infinity). Finally we compare our results
with the analogous well-known results for the standard telegraph process
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