931 resultados para TOP-DOWN
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Covert spatial attention produces biases in perceptual and neural responses in the absence of overt orienting movements. The neural mechanism that gives rise to these effects is poorly understood. Here we report the relation between fixational eye movements, namely eye vergence, and covert attention. Visual stimuli modulate the angle of eye vergence as a function of their ability to capture attention. This illustrates the relation between eye vergence and bottom-up attention. In visual and auditory cue/no-cue paradigms, the angle of vergence is greater in the cue condition than in the no-cue condition. This shows a top-down attention component. In conclusion, observations reveal a close link between covert attention and modulation in eye vergence during eye fixation. Our study suggests a basis for the use of eye vergence as a tool for measuring attention and may provide new insights into attention and perceptual disorders.
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This study analyzed high-density event-related potentials (ERPs) within an electrical neuroimaging framework to provide insights regarding the interaction between multisensory processes and stimulus probabilities. Specifically, we identified the spatiotemporal brain mechanisms by which the proportion of temporally congruent and task-irrelevant auditory information influences stimulus processing during a visual duration discrimination task. The spatial position (top/bottom) of the visual stimulus was indicative of how frequently the visual and auditory stimuli would be congruent in their duration (i.e., context of congruence). Stronger influences of irrelevant sound were observed when contexts associated with a high proportion of auditory-visual congruence repeated and also when contexts associated with a low proportion of congruence switched. Context of congruence and context transition resulted in weaker brain responses at 228 to 257 ms poststimulus to conditions giving rise to larger behavioral cross-modal interactions. Importantly, a control oddball task revealed that both congruent and incongruent audiovisual stimuli triggered equivalent non-linear multisensory interactions when congruence was not a relevant dimension. Collectively, these results are well explained by statistical learning, which links a particular context (here: a spatial location) with a certain level of top-down attentional control that further modulates cross-modal interactions based on whether a particular context repeated or changed. The current findings shed new light on the importance of context-based control over multisensory processing, whose influences multiplex across finer and broader time scales.
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Social responsibility, especially in the fields of education, society and peace, is one of the cornerstones of the olympic ideal and strategic vision (contribute to building a better world through sport). The article reviews the literature on organizational social responsibility (OSR) and the relationship between sport/olympism and OSR in order to examine the conditions governing the implementation and success of the International Olympic Committee's strategic vision. Several ways in which the IOC could promote a more ambitious and better-integrated social strategy: revise its performance model, notably evaluate and present in a social responsibility report; promote the adoption of OSR initiatives and strategies within the Olympic System from the bottom-up, rather than from the top-down; share best practices in the different countries for promoting and developing "sport for all"; create a World Agency for Development through Sport, or partnering and funding the international platform on sport and development; creating a World Agency for the International Governance of Sport. Two possible scenarios for the future of Olympic responsibility are finally discussed: strategy of "small steps" and a more ambitious local and global social strategy through sport and olympism.
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Top-down contextual influences play a major part in speech understanding, especially in hearing-impaired patients with deteriorated auditory input. Those influences are most obvious in difficult listening situations, such as listening to sentences in noise but can also be observed at the word level under more favorable conditions, as in one of the most commonly used tasks in audiology, i.e., repeating isolated words in silence. This study aimed to explore the role of top-down contextual influences and their dependence on lexical factors and patient-specific factors using standard clinical linguistic material. Spondaic word perception was tested in 160 hearing-impaired patients aged 23-88 years with a four-frequency average pure-tone threshold ranging from 21 to 88 dB HL. Sixty spondaic words were randomly presented at a level adjusted to correspond to a speech perception score ranging between 40 and 70% of the performance intensity function obtained using monosyllabic words. Phoneme and whole-word recognition scores were used to calculate two context-influence indices (the j factor and the ratio of word scores to phonemic scores) and were correlated with linguistic factors, such as the phonological neighborhood density and several indices of word occurrence frequencies. Contextual influence was greater for spondaic words than in similar studies using monosyllabic words, with an overall j factor of 2.07 (SD = 0.5). For both indices, context use decreased with increasing hearing loss once the average hearing loss exceeded 55 dB HL. In right-handed patients, significantly greater context influence was observed for words presented in the right ears than for words presented in the left, especially in patients with many years of education. The correlations between raw word scores (and context influence indices) and word occurrence frequencies showed a significant age-dependent effect, with a stronger correlation between perception scores and word occurrence frequencies when the occurrence frequencies were based on the years corresponding to the patients' youth, showing a "historic" word frequency effect. This effect was still observed for patients with few years of formal education, but recent occurrence frequencies based on current word exposure had a stronger influence for those patients, especially for younger ones.
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Climate change affects the rate of insect invasions as well as the abundance, distribution and impacts of such invasions on a global scale. Among the principal analytical approaches to predicting and understanding future impacts of biological invasions are Species Distribution Models (SDMs), typically in the form of correlative Ecological Niche Models (ENMs). An underlying assumption of ENMs is that species-environment relationships remain preserved during extrapolations in space and time, although this is widely criticised. The semi-mechanistic modelling platform, CLIMEX, employs a top-down approach using species ecophysiological traits and is able to avoid some of the issues of extrapolation, making it highly applicable to investigating biological invasions in the context of climate change. The tephritid fruit flies (Diptera: Tephritidae) comprise some of the most successful invasive species and serious economic pests around the world. Here we project 12 tephritid species CLIMEX models into future climate scenarios to examine overall patterns of climate suitability and forecast potential distributional changes for this group. We further compare the aggregate response of the group against species-specific responses. We then consider additional drivers of biological invasions to examine how invasion potential is influenced by climate, fruit production and trade indices. Considering the group of tephritid species examined here, climate change is predicted to decrease global climate suitability and to shift the cumulative distribution poleward. However, when examining species-level patterns, the predominant directionality of range shifts for 11 of the 12 species is eastward. Most notably, management will need to consider regional changes in fruit fly species invasion potential where high fruit production, trade indices and predicted distributions of these flies overlap.
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We propose a probabilistic object classifier for outdoor scene analysis as a first step in solving the problem of scene context generation. The method begins with a top-down control, which uses the previously learned models (appearance and absolute location) to obtain an initial pixel-level classification. This information provides us the core of objects, which is used to acquire a more accurate object model. Therefore, their growing by specific active regions allows us to obtain an accurate recognition of known regions. Next, a stage of general segmentation provides the segmentation of unknown regions by a bottom-strategy. Finally, the last stage tries to perform a region fusion of known and unknown segmented objects. The result is both a segmentation of the image and a recognition of each segment as a given object class or as an unknown segmented object. Furthermore, experimental results are shown and evaluated to prove the validity of our proposal
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Several studies have suggested a bilingual advantage in executive functions, presumably due to bilinguals' massive practice with language switching that requires executive resources, but the results are still somewhat controversial. Previous studies are also plagued by the inherent limitations of a natural groups design where the participant groups are bound to differ in many ways in addition to the variable used to classify them. In an attempt to introduce a complementary analysis approach, we employed multiple regression to study whether the performance of 30- to 75-year-old FinnishSwedish bilinguals (N = 38) on tasks measuring different executive functions (inhibition, updating, and set shifting) could be predicted by the frequency of language switches in everyday life (as measured by a language switching questionnaire), L2 age of acquisition, or by the self-estimated degree of use of both languages in everyday life. Most consistent effects were found for the set shifting task where a higher rate of everyday language switches was related to a smaller mixing cost in errors. Mixing cost is thought to reflect top-down management of competing task sets, thus resembling the bilingual situation where decisions of which language to use has to be made in each conversation. These findings provide additional support to the idea that some executive functions in bilinguals are affected by a lifelong experience in language switching and, perhaps even more importantly, suggest a complementary approach to the study of this issue.
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Tutkielmassa tarkastellaan Sarbanes-Oxley -lain Auditing Standard 5:n (AS 5) vaikutusta suomalaisten yhtiöiden tilintarkastukseen. Teoriaosuudessa käsitellään corporate governancea ja tilintarkastusta sen osana, COSO ERM -viitekehystä ja kontrolleja sekä Sarbanes Oxley -lakia. Tutkielman painopisteenä ovat AS 5:n sisältökokonaisuudet: mm. ylhäältä alas- ja riskiperusteinen lähestymistapa sekä turhien tarkastusprosessien poistaminen. Tutkimusaineisto kerättiin vuosina 2007–2009 erilaisista ammattilehdistä ja blogeista sekä haastattelemalla kolmea suurten tilintarkastusyhteisöjen tilintarkastajaa. AS 5 näyttää korostaneen riskiperusteisuutta tilintarkastuksessa sekä tehostaneen tilintarkastusprosessia mm. sallimalla aiempien vuosien tarkastustietojen entistä laajemmin käytön. Näyttää myös siltä, että AS 5 on alentanut tilintarkastuspalkkioita.
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In general, models of ecological systems can be broadly categorized as ’top-down’ or ’bottom-up’ models, based on the hierarchical level that the model processes are formulated on. The structure of a top-down, also known as phenomenological, population model can be interpreted in terms of population characteristics, but it typically lacks an interpretation on a more basic level. In contrast, bottom-up, also known as mechanistic, population models are derived from assumptions and processes on a more basic level, which allows interpretation of the model parameters in terms of individual behavior. Both approaches, phenomenological and mechanistic modelling, can have their advantages and disadvantages in different situations. However, mechanistically derived models might be better at capturing the properties of the system at hand, and thus give more accurate predictions. In particular, when models are used for evolutionary studies, mechanistic models are more appropriate, since natural selection takes place on the individual level, and in mechanistic models the direct connection between model parameters and individual properties has already been established. The purpose of this thesis is twofold. Firstly, a systematical way to derive mechanistic discrete-time population models is presented. The derivation is based on combining explicitly modelled, continuous processes on the individual level within a reproductive period with a discrete-time maturation process between reproductive periods. Secondly, as an example of how evolutionary studies can be carried out in mechanistic models, the evolution of the timing of reproduction is investigated. Thus, these two lines of research, derivation of mechanistic population models and evolutionary studies, are complementary to each other.
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BACKGROUND: The Cancer Fast-track Programme's aim was to reduce the time that elapsed between well-founded suspicion of breast, colorectal and lung cancer and the start of initial treatment in Catalonia (Spain). We sought to analyse its implementation and overall effectiveness. METHODS: A quantitative analysis of the programme was performed using data generated by the hospitals on the basis of seven fast-track monitoring indicators for the period 2006-2009. In addition, we conducted a qualitative study, based on 83 semistructured interviews with primary and specialised health professionals and health administrators, to obtain their perception of the programme's implementation. RESULTS: About half of all new patients with breast, lung or colorectal cancer were diagnosed via the fast track, though the cancer detection rate declined across the period. Mean time from detection of suspected cancer in primary care to start of initial treatment was 32 days for breast, 30 for colorectal and 37 for lung cancer (2009). Professionals associated with the implementation of the programme showed that general practitioners faced with suspicion of cancer had changed their conduct with the aim of preventing lags. Furthermore, hospitals were found to have pursued three specific implementation strategies (top-down, consensus-based and participatory), which made for the cohesion and sustainability of the circuits. CONCLUSION: The programme has contributed to speeding up diagnostic assessment and treatment of patients with suspicion of cancer, and to clarifying the patient pathway between primary and specialised care.
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The evaluation of uncertainty associated with an analytic result is an essential part of the measurement process. Recently, several approaches to evaluate the uncertainty in measurement have been developed. Here, the gas chromatography assay uncertainty for natural gas is compared by some of these approaches: the guide to the expression of uncertainty in measurement (GUM) approach, top-down approach (reproducibility estimate from an inter-laboratory study), Barwick & Ellison (data from validation), study of variability and fuzzy approach. The comparison shows that GUM, Barwick & Ellison and fuzzy approaches lead to comparable uncertainty evaluations, which does not happen with the top-down approach and study of variability by the absence of data normality.
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The general goal of the present work was to study whether spatial perceptual asymmetry initially observed in linguistic dichotic listening studies is related to the linguistic nature of the stimuli and/or is modality-specific, as well as to investigate whether the spatial perceptual/attentional asymmetry changes as a function of age and sensory deficit via praxis. Several dichotic listening studies with linguistic stimuli have shown that the inherent perceptual right ear advantage (REA), which presumably results from the left lateralized linguistic functions (bottom-up processes), can be modified with executive functions (top-down control). Executive functions mature slowly during childhood, are well developed in adulthood, and decline as a function of ageing. In Study I, the purpose was to investigate with a cross-sectional experiment from a lifespan perspective the age-related changes in top-down control of REA for linguistic stimuli in dichotic listening with a forced-attention paradigm (DL). In Study II, the aim was to determine whether the REA is linguistic-stimulus-specific or not, and whether the lifespan changes in perceptual asymmetry observed in dichotic listening would exist also in auditory spatial attention tasks that put load on attentional control. In Study III, using visual spatial attention tasks, mimicking the auditory tasks applied in Study II, it was investigated whether or not the stimulus-non-specific rightward spatial bias found in auditory modality is a multimodal phenomenon. Finally, as it has been suggested that the absence of visual input in blind participants leads to improved auditory spatial perceptual and cognitive skills, the aim in Study IV was to determine, whether blindness modifies the ear advantage in DL. Altogether 180-190 right-handed participants between 5 and 79 years of age were studied in Studies I to III, and in Study IV the performance of 14 blind individuals was compared with that of 129 normally sighted individuals. The results showed that only rightward spatial bias was observed in tasks with intensive attentional load, independent of the type of stimuli (linguistic vs. non-linguistic) or the modality (auditory vs. visual). This multimodal rightward spatial bias probably results from a complex interaction of asymmetrical perceptual, attentional, and/or motor mechanisms. Most importantly, the strength of the rightward spatial bias changed as a function of age and augmented praxis due to sensory deficit. The efficiency of the performance in spatial attention tasks and the ability to overcome the rightward spatial bias increased during childhood, was at its best in young adulthood, and decreased as a function of ageing. Between the ages of 5 and 11 years probably at first develops movement and impulse control, followed by the gradual development of abilities to inhibit distractions and disengage attention. The errors especially in bilateral stimulus conditions suggest that a mild phenomenon resembling extinction can be observed throughout the lifespan, but especially the ability to distribute attention to multiple targets simultaneously decreases in the course of ageing. Blindness enhances the processing of auditory bilateral linguistic stimuli, the ability to overcome a stimulus-driven laterality effect related to speech sound perception, and the ability to direct attention to an appropriate spatial location. It was concluded that the ability to voluntarily suppress and inhibit the multimodal rightward spatial bias changes as a function of age and praxis due to sensory deficit and probably reflects the developmental level of executive functions.
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Rajavartiolaitos on yhteiskunnallisesti merkittävä turvallisuusviranomainen. Erityisesti laitoksen merellinen rooli sisäisen turvallisuuden kentässä on korostunut sen lakisääteisten merellisten tehtävien ansiosta. Rajavartiolaitoksen merelliselle roolille onkin asetettu huomattavat tavoitteet viraston strategia-asiakirjassa. Rajavartiolaitoksen strategian toimeenpanoa tai siinä suoriutumista ei tieteellisen tutkimuksen keinoin ole aiemmin tutkittu. Tutkimuksen tarkoituksena oli muodostaa rajavartiolaitoksen strategian toimeenpanon tutkimusta tukeva teoreettinen viitekehys. Näkökulma viitekehyksen muodostamiseksi oli merellinen. Kyseisen viitekehyksen avulla mahdollistetaan strategian toimeenpanossa onnistumisen tutkiminen nimenomaisesti merellisestä perspektiivistä. Tutkittaessa toimeenpanoon liittyvien tekijöiden toteutumista tai ilmentymiä rajavartiolaitoksen implementaatioprosessissa voidaan päätyä myös arvioon sen yhteiskunnallisesta vaikuttavuudesta ja viimekädessä roolista. Jatkotutkimuksen tehtävä on varsinainen implementaation tutkiminen nyt muodostettua teoreettista viitekehystä hyödyntäen. Implementaation tutkimuskenttään liittyy useita erilaisia teoreettisia suuntauksia. Teorialähtöisen sisällönanalyysin avulla pyrittiin muodostamaan kattava kuva vallitsevista teorioista varsinaisen paradigman puuttuessa. Sisällönanalyysin analyysirungoksi valittiin topdown- teorian käsitemaailma. Analysoitavat teokset valittiin implementaatiotutkimuksen vahvinta perinnettä edustavien tutkimusjulkaisujen ja artikkeleiden joukosta pyrkimyksenä huomioimaan tutkimuksen alan valtavirtaan kuuluvat merkittävimmät lähestymistavat. Rajavartiolaitoksen strategian toimeenpanon tutkimusta tukevan teorian muodostamiseksi tuli sisällönanalyysistä kumpuavat teoriat sitoa soveltuvin osin reaalimaailmaan eli viraston prosesseihin ja toimintaympäristöön. Tätä varten muodostettiin käsitys rajavartiolaitoksen strategisesta olosuhdeympäristöstä sekä sidottiin toimeenpanon prosessit governanssin teoriaan käyttäen Multiple Govenance Framework -viitekehystä (MGF). Varsinainen viitekehys ja siihen liittyvät tekijät valittiin analysoidusta materiaalista tukeutuen abduktiiviseen päättelyyn. Tutkimuksen johtopäätöksenä voidaan todeta rajavartiolaitoksen edustavan tietyssä määrin top-down-tutkimusperinteeseen liittyviä piirteitä. Tämä teoria ei kuitenkaan kaikilta osin huomio niitä erityispiirteitä, jotka tutkimuksessa tunnistettiin. Yhdistämällä MGF:n ominaisuudet ja top-down-teoriasta soveltuvat tekijät, muodostettiin hypoteesi rajavartiolaitoksen implementaatiota tukevasta viitekehyksestä. Viitekehys sidottiin rajavartiolaitokseen, mutta varsinainen operationalisointi jätettiin jatkotutkimuksen tehtäväksi.
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Tutkielman aiheena on tuloskortin kritiikki ja sen analysointi kontingenssiteorian näkökulmasta. Tutkimuksen kohdeyrityksen tuloskortin kritiikkiä on verrattu laskentatoimen tieteellisessä keskustelussa esitettyyn kritiikkiin. Tuloskortin kritiikin ja kontingenssiteorian näkökulmien perusteella tutkimuksen kohdeyrityksen suorituskyvyn mittaamisen kehittämiskohteita on tunnistettu. Tutkimuksen kohdeyritys on suomalainen korkean teknologian yritys, joka on osa yhdysvaltalaista globaalia konsernia. Tutkimuksen teoreettinen tausta perustuu kontingenssiteoriaan ja tuloskortin ja suorituskyvyn mittaamisen doktriiniin. Tutkimus on luonteeltaan toimintaanalyyttinen. Tutkimusaineisto koostuu tieteellisistä artikkeleista, kirjallisuudesta ja kohdeyrityksessä suoritetuista teemahaastatteluista. Tutkielman teoriaosa alkaa Balanced Scorecardin ja muiden tuloskorttien esittelyllä ja vertailulla. Kontingenssiteorian käsittely perustuu tieteellisessä kirjallisuudessa yleisiin tilannetekijöihin: ulkoinen ympäristö, teknologia, strategia ja organisaatiorakenne. Muista tilannetekijöistä käsiteltiin kulttuuripiiri, joka on relevantti tutkimuksen kohdeyrityksen tarkastelussa. Teoreettisen osan selkärangan muodostaa tuloskortin kritiikin analysointi, joka on jaettu Balanced Scorecardin kritiikkiin ja yleiseen tuloskortin kritiikkiin. Kritiikin sisältöä on tulkittu myös kontingenssiteorian avulla. Tutkimuksen kohdeyritys käyttää kolmea erilaista tuloskorttimallia. Tuloskortin kritiikki kohdeyrityksessä vastaa pääosin tieteellisessä keskustelussa esitettyä kritiikkiä. Tuloskortin näkökulmien väliset suhteet, liityntä strategiaan, puutteellinen ajallinen ulottuvuus ja rooli top-down –johtamismallin työkaluna olivat yleisimmät kritiikin kohteet. Kohdeyrityksessä esille nousivat myös tutkimuksen ja tuotekehityksen mittaamisen haasteellisuus, organisaation funktionaaliset rajaaidat, yhdysvaltalainen toiminnanohjaamisen malli ja kohdeyrityksen rooli osana globaalia konsernia. Kontingenssitekijöistä kritiikkiä eniten selittävät ulkoinen ympäristö, organisaatiorakenne ja kulttuuripiiri. Tutkimuksen kohdeyrityksessä tuloskortin kehittämistarpeet kohdistuvat organisaatiorakenteen muokkaamiseen, tuloskortin tavoitteiden viestintään henkilöstölle, tietoteknisiin ratkaisuihin ja konsernin osana toimimiseen. Kontingenssitekijöiden huomioiminen antaa tutkimuksen perusteella hyvän lähtökohdan tuloskortin ja yleisesti suorituskyvyn mittaamisen kehittämiselle yrityksissä.
Resumo:
Prerequisites and effects of proactive and preventive psycho-social student welfare activities in Finnish preschool and elementary school were of interest in the present thesis. So far, Finnish student welfare work has mainly focused on interventions and individuals, and the voluminous possibilities to enhance well-being of all students as a part of everyday school work have not been fully exploited. Consequently, in this thesis three goals were set: (1) To present concrete examples of proactive and preventive psycho-social student welfare activities in Finnish basic education; (2) To investigate measurable positive effects of proactive and preventive activities; and (3) To investigate implementation of proactive and preventive activities in ecological contexts. Two prominent phenomena in preschool and elementary school years—transition to formal schooling and school bullying—were chosen as examples of critical situations that are appropriate targets for proactive and preventive psycho-social student welfare activities. Until lately, the procedures concerning both school transitions and school bullying have been rather problem-focused and reactive in nature. Theoretically, we lean on the bioecological model of development by Bronfenbrenner and Morris with concentric micro-, meso-, exo- and macrosystems. Data were drawn from two large-scale research projects, the longitudinal First Steps Study: Interactive Learning in the Child–Parent– Teacher Triangle, and the Evaluation Study of the National Antibullying Program KiVa. In Study I, we found that the academic skills of children from preschool–elementary school pairs that implemented several supportive activities during the preschool year developed more quickly from preschool to Grade 1 compared with the skills of children from pairs that used fewer practices. In Study II, we focused on possible effects of proactive and preventive actions on teachers and found that participation in the KiVa antibullying program influenced teachers‘ self-evaluated competence to tackle bullying. In Studies III and IV, we investigated factors that affect implementation rate of these proactive and preventive actions. In Study III, we found that principal‘s commitment and support for antibullying work has a clear-cut positive effect on implementation adherence of student lessons of the KiVa antibullying program. The more teachers experience support for and commitment to anti-bullying work from their principal, the more they report having covered KiVa student lessons and topics. In Study IV, we wanted to find out why some schools implement several useful and inexpensive transition practices, whereas other schools use only a few of them. We were interested in broadening the scope and looking at local-level (exosystem) qualities, and, in fact, the local-level activities and guidelines, along with teacherreported importance of the transition practices, were the only factors significantly associated with the implementation rate of transition practices between elementary schools and partner preschools. Teacher- and school-level factors available in this study turned out to be mostly not significant. To summarize, the results confirm that school-based promotion and prevention activities may have beneficial effects not only on students but also on teachers. Second, various top-down processes, such as engagement at the level of elementary school principals or local administration may enhance implementation of these beneficial activities. The main message is that when aiming to support the lives of children the primary focus should be on adults. In future, promotion of psychosocial well-being and the intrinsic value of inter- and intrapersonal skills need to be strengthened in the Finnish educational systems. Future research efforts in student welfare and school psychology, as well as focused training for psychologists in educational contexts, should be encouraged in the departments of psychology and education in Finnish universities. Moreover, a specific research centre for school health and well-being should be established.