Vaneritehtaan kustannustehokkuuden arvioimiseen käytettävän simulaatiojärjestelmän kehittäminen

Tämän työn tarkoituksena oli luoda kokonaisvaltainen tuotannollinen simulaatiomalli vaneritehtaasta sekä tutkia kustannuslaskennan mahdollisuuksia mallin yhteydessä. Perusolettamuksena on, että jos tuotannollinen malli toimii esikuvansa mukaisesti, myös sillä laskettuun kustannustietoon voidaan luottaa. Johdantona on tarkasteltu työn perustana olevia teorialähteitä. Ensimmäisenä asiana on esitetty vanerin valmistusprosessia ja siinä käytettyjä linja- ja laitetyyppejä. Toisena asiana on esitetty simulaatiotutkimuksen periaatteita, lainalaisuuksia ja mahdollisuuksia. Lisäksi on tarkasteltu kustannuslaskentaa, sen eri periaatteita ja muotoja sekä tuotannon- ja varastonohjausta. Aineistona ja menetelminä työssä on esitetty simulaatiomallin luomiseen tarvittavan pohjatiedon kerääminen sekä soveltaminen. Sitten on kuvattu tehdasmallin muodostavat eri tuotantolinjoja kuvaavat komponentit ja mallin käyttöliittymä. Lopuksi on kuvattu teoreettisen tehdasmallin soveltaminen todellisen vaneritehtaan mukaiseksi. Sovelletulla mallilla on ajettu kolme erilaista vuorokausituotantoa ja niistä saatua kustannustietoa on vertailtu optimitilannetta kuvaavaan taulukkoon.

Monitoring of praseodymium(III) ions in aqueous solutions, soil and sediment samples by a PVC membrane sensor based on a furan-triazole derivative

A furan-triazole derivative has been explored as an ionophore for preparation of a highly selective Pr(III) membrane sensor. The proposed sensor exhibits a Nernstian response for Pr(III) activity over a wide concentration range with a detection limit of 5.2×10-8 M. Its response is independent of pH of the solution in the range 3.0-8.8 and offers the advantages of fast response time. To investigate the analytical applicability of the sensor, it was applied successfully as an indicator electrode in potentiometric titration of Pr(III) solution and also in the direct and indirect determination of trace Pr(III) ions in some samples.

Implementing gateway monitoring service for infrastructure sensor networks

Wireless sensor networks and its applications have been widely researched and implemented in both commercial and non commercial areas. The usage of wireless sensor network has developed its market from military usage to daily use of human livings. Wireless sensor network applications from monitoring prospect are used in home monitoring, farm fields and habitant monitoring to buildings structural monitoring. As the usage boundaries of wireless sensor networks and its applications are emerging there are definite ongoing research, such as lifetime for wireless sensor network, security of sensor nodes and expanding the applications with modern day scenarios of applications as web services. The main focus in this thesis work is to study and implement monitoring application for infrastructure based sensor network and expand its usability as web service to facilitate mobile clients. The developed application is implemented for wireless sensor nodes information collection and monitoring purpose enabling home or office environment remote monitoring for a user.

Kansainvälisen kaupan arvoketjujen sääntely. Yhteiskuntavastuun ja ennakoivan oikeuden tarkastelua

Tausta Kansainvälinen kauppa on globaalia toimintaa, jossa tavaroiden ja palveluiden tuottaminen ja kuluttaminen on jakautunut maapallon eri osiin. Arvoketjukäsitteellä korostetaan eri toimijoiden panosta lopputuotteen valmistamiseksi, sekä yhteisten tavoitteiden merkitystä. Toimijaverkostot ovat moni-ilmeisiä ja monimutkaisia. Globaalin kaupan toinen tärkeä piirre on yhteiskuntavastuu, joka tulee esiin niin yksityisen kuin julkisen sektorin toiminnassa. Sen toteuttaminen asettaa suuria haasteita sekä yksityisen että julkisen sektorin toimijoille. Kansallisvaltion mahdollisuudet hallita globaaleja kaupan arvoketjuja julkisella sääntelyllä on osoittautunut ongelmalliseksi. Tutkimuskysymykset Tämä tutkimus on oikeustieteen alaan kuuluva sääntelytutkimuksen artikkeliväitöskirja, joka on tutkimusotteeltaan poikkitieteellinen. Tutkimus pyrkii kaikkiaan valaisemaan yksityisen sääntelyn käyttömahdollisuuksia ja rajoituksia elinkeinotoiminnassa. Keskeisessä roolissa oikeustieteen rinnalla on liiketaloustieteen tutkimus. Tutkimuskysymykset ovat ensinnäkin, mistä nousee kansainvälistä kauppaa koskeva yksityisen sääntelyn tarve ja toiseksi, mikä motivoi yrityksiä yksityiseen sääntelyyn tai itsesääntelyyn. Lopuksi pohditaan, miten lainsäätäjän tulisi suhtautua yksityiseen sääntelyyn. Tutkimuskysymyksiin vastaamalla syvennetään ja täsmennetään oikeustieteen piirissä tehtävää tutkimusta ennakoivasta oikeudesta. Menetelmät ja aineistot Tutkimus on oikeusvertaileva tutkimus, jossa pääpaino on yksityisessä sääntelyssä. Tutkimusaineisto nojautuu eri tieteenaloilla tehtyihin sekä kvalitatiivisiin että kvantitatiivisiin empiirisiin sääntelyjärjestelmien käyttöä ja toimivuutta koskeviin tutkimuksiin sekä tutkijan tekemään 42:en, metsäsektorin, elintarvikealan, vaatetusalan sekä vähittäiskaupan piirissä käytössä olevan sääntelyjärjestelmän analyysiin. Johtopäätökset Yksityisen sääntelyn tarve nousee tarpeesta hallita globaaleja arvoketjuja kohti yhteisiä tavoitteita. Tulevan lainsäädännön uhan sijasta yrityksiä motivoi yksityiseen sääntelyyn kilpailuedun tavoitteluun liittyvät tekijät. Koska kilpailuetuun yhä yleisemmin sisältyy yhteiskuntavastuullisuus, ovat yritysten tavoitteet ja julkisen sektorin tavoitteet lähentyneet. Erilaisten kansalaisjärjestöjen rooli kasvaa koko ajan. Ne osallistuvat vahvasti niin yksityisen sääntelyn laadintaan kuin myös sääntöjen valvontaan. Yksityisen sääntelyn tavoitteet ovat aiemmin liittyneet ympäristönsuojelun painottamiseen ja elintarviketurvallisuuteen erityisesti metsäsektorilla ja elintarvikealalla, myöhemmin sosiaalisen vastuullisuuden parantaminen on myös tullut painokkaammin esiin. Kansainvälisen kaupan piirissä syntynyttä yksityisen sääntelyn ilmiötä kuvataan tässä ennakoiva oikeus –käsitteellä. Aiempi tutkimus rajoittui tarkastelemaan ilmiötä vain ennakoivana lähestymistapana oikeuteen. Tässä painopiste on sen sijaan ennakoivan lähestymistavan avulla aikaansaaduissa sääntelyn välineissä ja lopputuloksissa: mahdollistavassa, valtaistavassa, dynaamisessa ja käyttäjäystävällisessä oikeudessa, jonka avulla luodaan mahdollisuuksia, ennalta ehkäistään ja hallitaan riskejä eikä pelkästään ratkaista jo syntyneitä ongelmia. Käsitteen sisältöä avataan tutkimuksessa sekä sääntelyjärjestelmien sisällöllisen tarkastelun että prosessiin liittyvän tarkastelun avulla.

TURKU TAKING STEPS TOWARDS FUTURE - technology supports physical activity

Physical activity (PA) is an important field of healthcare research internationally and within Finland. As technology devices and services penetrate deeper levels within society, the need for studying the usefulness for PA turns vital. We started this research work by reviewing literature consisting of two hundred research journals, all of which have found technology to significantly improve an individual’s ability to get motivation and achieve officially recommended levels of physical activity, like the 10000 steps a day, being tracked with the help of pedometers. Physical activity recommendations require sustained encouragement, consistent performance in order to achieve the long term benefits. We surveyed within the city of Turku, how the motivation levels and thirty three other criterions encompassing technology awareness, adoption and usage attitudes are impacted. Our aim was to know the factors responsible for achieving consistent growth in activity levels within the individuals and focus groups, as well as to determine the causes of failures and for collecting user experience feedback. The survey results were quite interesting and contain impeccable information for this field. While the focus groups confirmed the theory established by past studies within our literature review, it also establishes our research propositions that ict tools and services have provided and can further add higher benefits and value to individuals in tracking and maintain their activity levels consistently for longer time durations. This thesis includes two new models which dictate technology and physical activity adoption patterns based on four easy to evaluate criterions, thereby helping the healthcare providers to recommend improvements and address issues with an easy rule based approach. This research work provides vital clues on technology based healthcare objectives and achievement of standard PA recommendations by people within Turku and nearby regions.

Turun seudun turvallisen ja kestävän liikkumisen suunnitelma

Turun seudun turvallisen ja kestävän liikkumisen suunnitelma on laadittu seudun kuntien ja Varsinais-Suomen ELY-keskuksen yhteistyönä. Suunnitelmassa on selvitetty liikenneturvallisuuden, liikkumisen, toimintaympäristön ja liikennejärjestelmän nykytilaa sekä kartoitettu liikenneturvallisuusongelmia erilaisten analyysien ja kyselyiden avulla. Nykytila-analyysin pohjalta on asetettu liikenneturvallisuustyön visio ja tavoitteet sekä määritetty toimenpide-ehdotukset. Tavoitteisiin pääsemistä tukevat liikenneympäristön parantamistoimenpiteiden ohjelma, liikkumisen ohjauksen toimintaohjelma sekä hallintokuntien liikenneturvallisuustyön toimenpiteistä kootut toimintasuunnitelmat. Onnettomuusanalyysin perusteella liikenneturvallisuuden tila oli Turun seudulla hieman koko Suomen keskiarvoa heikompi. Seudulla tapahtui vuosina 2001-2010 henkilövahinkoon johtaneita onnettomuuksia keskimäärin 132 / 100 000 asukasta, kun vastaava luku oli 126 koko maan osalta. Kuolemaan johtaneita onnettomuuksia tapahtui seudulla vähemmän, mutta loukkaantumiseen johtaneita onnettomuuksia koko maan keskiarvoa enemmän. Onnettomuuksissa kuoli tai loukkaantui koko maan keskiarvoa enemmän jalankulkijoita ja polkupyöräilijöitä. Lukumäärällisesti eniten onnettomuuksia tapahtui 18–19-vuotiaille, mutta henkilövahinkoon johtaneita onnettomuuksia tapahtui selvästi eniten 15–16-vuotiaille. Seudulla tapahtuneista liikenneonnettomuuksista aiheutui vuosittain keskimäärin 127,2 miljoonan euron kustannukset, josta kuntien osuus oli vuosittain noin 22,3 miljoonaa euroa. Asukkaille suunnatun kyselyn mukaan sekä työmatkat että lyhyet vapaa-ajan matkat tehtiin useimmiten henkilöautolla. Koululaisia pidettiin turvattomimpana tienkäyttäjäryhmänä, ja kävelyä sekä pyöräilyä turvattomimpina kulkutapoina. Välinpitämättömyyttä pidettiin merkittävimpänä syynä erilaisiin liikennerikkomuksiin ja tärkeimmäksi kehittämistarpeeksi nousi liikennekäyttäytyminen. Yhdyskuntarakenteen ja toimintaympäristön analyysin perusteella seudulla on hyvät edellytykset kestävien kulkumuotojen kuten joukkoliikenteen houkuttelevuuden lisäämiselle sekä kävelyn ja pyöräilyn verkoston kehittämiselle. Onnettomuusanalyysin ja valtakunnallisten tavoitteiden pohjalta Turun seudulle asetettiin liikenneturvallisuustyön tavoitteet. Tavoitelaskelman mukaan liikennekuolemien ja loukkaantuneiden määrä tulee puolittaa vuosien 2006-2010 keskiarvosta vuoteen 2020 mennessä. Tavoitteen mukaan liikenteessä kuolee enintään 6 (lähtötaso 12) ja loukkaantuu 236 (lähtötaso 471) vuonna 2020. Vaikutusarvion perusteella voidaan arvioida päästävän tavoitteeseen suunnitelmakauden aikana. Tavoitteiden saavuttaminen on kuitenkin haasteellista ja edellyttää tehokasta yhteistyötä eri tahojen välillä. Tavoitteeseen tulee pyrkiä laajaa keinovalikoimaa käyttäen. Suunnitelmatyön aikana aktivoitiin kuntien turvallisen ja kestävän liikkumisen ryhmät, joiden toiminnan tueksi laadittiin toimintasuunnitelmat sekä vuosikello työn eri vaiheista. Ryhmät vastaavat suunnitelman toteuttamisesta, toteutumisen seurannasta ja tarvittaessa päivittämisestä.

Detection of the basement membrane-degrading proteolytic activity of Paracoccidioides brasiliensis after SDS-PAGE using agarose overlays containing Abz-MKALTLQ-EDDnp

We have characterized, in the Paracoccidioides brasiliensis yeast phase, an exocellular SH-dependent serine proteinase activity against Abz-MKRLTL-EDDnp and analogous fluorescent-quenched peptides, and showed that it is also active against constituents of the basement membrane in vitro. In the present study, we separated the components of P. brasiliensis culture filtrates by electrophoresis and demonstrated that the serine-thiol exocellular proteinase has a diffuse and heterogeneous migration by SDS-PAGE, localizing in a region between 69 and 43 kDa. The hydrolytic activity was demonstrable after SDS-PAGE using buffered agarose overlays of Abz-MKALTLQ-EDDnp, following incubation at 37oC, and detection of fluorescent bands with a UV transilluminator. Hydrolysis was more intense when incubation was carried out at basic pH, and was completely inhibited with 2.5 mM PMSF and partially with sodium 7-hydroxymercuribenzoate (2.5 mM p-HMB), suggesting its serine-thiol nature. A proteolytic band with similar characteristics was observed in conventional gelatin zymograms, but could not be correlated with a silver-stained component. Detection of the serine-thiol proteinase in substrate gels after SDS-PAGE provides a useful way of monitoring purification of the basement membrane degrading enzyme.

Postprandial symptoms in dysmotility-like functional dyspepsia are not related to disturbances of gastric myoelectrical activity

Gastric dysrhythmias, such as tachy- or bradygastria, have been reported in patients with functional dyspepsia (FD), but their role in symptom production is uncertain. It is also not known whether gastric dysrhythmias in these patients can be elicited by physiological gastric distension with a meal. We investigated the relationships between symptoms after ingestion of different volumes of water following a test meal and gastric dysrhythmias in FD patients. Fourteen patients with dysmotility-like FD and 13 healthy volunteers underwent paired electrogastrography (EGG) studies. Fasted subjects ingested 150 ml of yoghurt with either 150 ml (low volume) or 300 ml (high volume) water in random order. Fasting and fed EGGs with monitoring of symptoms were performed in both studies. Ten FD patients (71.4%) reported upper abdominal discomfort and bloating after the low volume meal, but only one (7.1%) presented an abnormal EGG (dominant frequency in the 2-4-cpm range: 58%). Following the high volume meal, 7 patients (50%) had symptoms, but none had EGG abnormalities. No significant differences were found between FD patients and controls for any of the EGG variables, in any test. In FD patients with postprandial symptoms, the percentage of the EGG dominant frequency in the normal range (median, 84.6%; range, 76.0-100.0%) was similar (P > 0.20) to that in those without symptoms (88.5%; 75.0-100.0%). We conclude that disturbances of gastric myoelectrical activity are unlikely to play a role in the origin of postprandial upper abdominal discomfort and bloating in dysmotility-like FD.

Semantic and fuzzy modelling for human behaviour recognition in smart spaces : a case study on ambient assisted living.

Human activity recognition in everyday environments is a critical, but challenging task in Ambient Intelligence applications to achieve proper Ambient Assisted Living, and key challenges still remain to be dealt with to realize robust methods. One of the major limitations of the Ambient Intelligence systems today is the lack of semantic models of those activities on the environment, so that the system can recognize the speci c activity being performed by the user(s) and act accordingly. In this context, this thesis addresses the general problem of knowledge representation in Smart Spaces. The main objective is to develop knowledge-based models, equipped with semantics to learn, infer and monitor human behaviours in Smart Spaces. Moreover, it is easy to recognize that some aspects of this problem have a high degree of uncertainty, and therefore, the developed models must be equipped with mechanisms to manage this type of information. A fuzzy ontology and a semantic hybrid system are presented to allow modelling and recognition of a set of complex real-life scenarios where vagueness and uncertainty are inherent to the human nature of the users that perform it. The handling of uncertain, incomplete and vague data (i.e., missing sensor readings and activity execution variations, since human behaviour is non-deterministic) is approached for the rst time through a fuzzy ontology validated on real-time settings within a hybrid data-driven and knowledgebased architecture. The semantics of activities, sub-activities and real-time object interaction are taken into consideration. The proposed framework consists of two main modules: the low-level sub-activity recognizer and the high-level activity recognizer. The rst module detects sub-activities (i.e., actions or basic activities) that take input data directly from a depth sensor (Kinect). The main contribution of this thesis tackles the second component of the hybrid system, which lays on top of the previous one, in a superior level of abstraction, and acquires the input data from the rst module's output, and executes ontological inference to provide users, activities and their in uence in the environment, with semantics. This component is thus knowledge-based, and a fuzzy ontology was designed to model the high-level activities. Since activity recognition requires context-awareness and the ability to discriminate among activities in di erent environments, the semantic framework allows for modelling common-sense knowledge in the form of a rule-based system that supports expressions close to natural language in the form of fuzzy linguistic labels. The framework advantages have been evaluated with a challenging and new public dataset, CAD-120, achieving an accuracy of 90.1% and 91.1% respectively for low and high-level activities. This entails an improvement over both, entirely data-driven approaches, and merely ontology-based approaches. As an added value, for the system to be su ciently simple and exible to be managed by non-expert users, and thus, facilitate the transfer of research to industry, a development framework composed by a programming toolbox, a hybrid crisp and fuzzy architecture, and graphical models to represent and con gure human behaviour in Smart Spaces, were developed in order to provide the framework with more usability in the nal application. As a result, human behaviour recognition can help assisting people with special needs such as in healthcare, independent elderly living, in remote rehabilitation monitoring, industrial process guideline control, and many other cases. This thesis shows use cases in these areas.

Liikunnan ja videopelien liittäminen yhteen

Tässä työssä esitämme konseptin liikunnan ja videopelien liittämisestä yhteen ekosysteemiin, jotta käyttäjät motivoituisivat liikkumaan. Käytämme kevennettyä systemaattista kirjallisuuskatsausta selvittääksemme viimeisimmät tutkimukset aiheesta ja teemme kyselytutkimuksen ymmärtääksemme, mitä pelaajat ovat mieltä fyysisestä kuntoilusta saatavista digitaalisista palkinnoista. Lisäksi toteutamme prototyypin soittaaksemme konseptimme toteutuskelpoisuuden. Tuloksemme osoittavat, että on olemassa ihmisiä, jotka olisivat halukkaita liikkumaan saadakseen palkintoja peleistä sekä videopelien ja liikunnan seuranta -sovellusten liittäminen yhteen on teknisesti toteuttamiskelpoista.

User Experience of Geocaching and Its Application to Tourism and Education

Advances in technology have provided new ways of using entertainment and game technology to foster human interaction. Games and playing with games have always been an important part of people’s everyday lives. Traditionally, human-computer interaction (HCI) research was seen as a psychological cognitive science focused on human factors, with engineering sciences as the computer science part of it. Although cognitive science has made significant progress over the past decade, the influence of people’s emotions on design networks is increasingly important, especially when the primary goal is to challenge and entertain users (Norman 2002). Game developers have explored the key issues in game design and identified that the driving force in the success of games is user experience. User-centered design integrates knowledge of users’ activity practices, needs, and preferences into the design process. Geocaching is a location-based treasure hunt game created by a community of players. Players use GPS (Global Position System) technology to find “treasures” and create their own geocaches; the game can be developed when the players invent caches and used more imagination to creations the caches. This doctoral dissertation explores user experience of geocaching and its applications in tourism and education. Globally, based on the Geocaching.com webpage, geocaching has been played about 180 countries and there are more than 10 million registered geocachers worldwide (Geocaching.com, 25.11.2014). This dissertation develops and presents an interaction model called the GameFlow Experience model that can be used to support the design of treasure hunt applications in tourism and education contexts. The GameFlow Model presents and clarifies various experiences; it provides such experiences in a real-life context, offers desirable design targets to be utilized in service design, and offers a perspective to consider when evaluating the success of adventure game concepts. User-centered game designs have adapted to human factor research in mainstream computing science. For many years, the user-centered design approach has been the most important research field in software development. Research has been focusing on user-centered design in software development such as office programs, but the same ideas and theories that will reflect the needs of a user-centered research are now also being applied to game design (Charles et al. 2005.) For several years, we have seen a growing interest in user experience design. Digital games are experience providers, and game developers need tools to better understand the user experience related to products and services they have created. This thesis aims to present what the user experience is in geocaching and treasure hunt games and how it can be used to develop new concepts for the treasure hunt. Engineers, designers, and researchers should have a clear understanding of what user experience is, what its parts are, and most importantly, how we can influence user satisfaction. In addition, we need to understand how users interact with electronic products and people, and how different elements synergize their experiences. This doctoral dissertation represents pioneering work on the user experience of geocaching and treasure hunt games in the context of tourism and education. The research also provides a model for game developers who are planning treasure hunt concepts.

Deoxynivalenol (DON) degradation and peroxidase enzyme activity in submerged fermentation

This work aims to evaluate deoxynivalenol degradation by Aspergillus oryzae and Rhizopus oryzae in a submerged fermentation system and to correlate it to the activity of oxydo-reductase enzymes. The submerged medium consisted of sterile distilled water contaminated with 50 μg of DON and 4 × 10(6) spore.mL-1 inoculum of Aspergillus oryzae and Rhizopus oryzae species, respectively in each experiment. Sampling was performed every 24 hours for monitoring the peroxidase specific activity, and every 48 hours for determining mycotoxin levels. Results showed that the fungi species were able to decrease DON levels as the peroxidase activity increased. The 48 hours fermentation interval presented the highest peroxidase specific activity (ΔABS/minute.μg.protein-1), 800 and 198, while the highest DON degradation velocity was 10.8 and 12.4 ppb/hour, respectively in both cases for Rhizopus oryzae and Aspergillus oryzae.

Emergence of normative beliefs legitimizing antisocial behaviour in adolescents : the roles of monitoring, attachment, and temperament /

Beliefs about the rightness or wrongness of engaging in various antisocial acts, referred to here as nonnative beliefs legitimizing antisocial behaviour (nblab), have been shown to playa role in the emergence oflater antisocial behaviour. The current study represented an attempt to understand whether parental monitoring and parent-child attachment have differential relationships with these antisocial nonnative beliefs in adolescents of different temperaments. The participants, 7135 adolescents in 25 high schools (ages 10- 18 years, M = 15.7) completed a wide-ranging questionnaire as part of the broad Youth Lifestyle Choices - Community University Research Alliance project, whose goal is to identify and describe the major developmental pathways of risk behaviours and resilience in youth. Two aspects of monitoring (monitoring knowledge and surveillance/tracking), attachment security, and two measures of temperament (activity level and approach) were examined for main effects and in interactions as predictors of adolescent nonnative beliefs. All of these measures were based on adolescent self-ratings on either 3- or 4-point Likert-type scales. Several important results emerged from the study. Males were higher than females in nblab; parental monitoring knowledge and adolescent attachment security were negatively related to nblab; and temperamental activity level was positively related. Monitoring knowledge, the strongest of the predictors, was much more strongly related to nonnative beliefs than was parental surveillance/tracking, supporting the contention that it is how much parents actually know, and not their surveillance efforts, that predict adolescent nonnative beliefs. A surprising finding that is of the utmost importance was that, although several of the interactions tested were significant, none were considered to be of a meaningful magnitude (defined as sr^ > .01). The current study supported the suggestion that normative beliefs legitimizing antisocial behaviour are multiply determined, and the results were discussed with respect to the observed differential relations of parental monitoring, parent-child attachment, temperament, age, and gender to antisocial normative beliefs in adolescents. Also discussed were the need to test other parenting, temperament, and other variables that may be involved in the development of nblab; the need to directly test possible mechanisms explaining the links among the variables; and the usefulness of longitudinal research in determining possible directions of causality and developmental changes in the relationships.

Electrophysiological correlates of performance monitoring in middle and late adolescence

The ability to monitor and evaluate the consequences of ongoing behaviors and coordinate behavioral adjustments seems to rely on networks including the anterior cingulate cortex (ACC) and phasic changes in dopamine activity. Activity (and presumably functional maturation) of the ACC may be indirectly measured using the error-related negativity (ERN), an event-related potential (ERP) component that is hypothesized to reflect activity of the automatic response monitoring system. To date, no studies have examined the measurement reliability of the ERN as a trait-like measure of response monitoring, its development in mid- and late- adolescence as well as its relation to risk-taking and empathic ability, two traits linked to dopaminergic and ACC activity. Utilizing a large sample of 15- and 18-year-old males, the present study examined the test-retest reliability of the ERN, age-related changes in the ERN and other components of the ERP associated with error monitoring (the Pe and CRN), and the relations of the error-related ERP components to personality traits of risk propensity and empathy. Results indicated good test-retest reliability of the ERN providing important validation of the ERN as a stable and possibly trait-like electrophysiological correlate of performance monitoring. Ofthe three components, only the ERN was of greater amplitude for the older adolescents suggesting that its ACC network is functionally late to mature, due to either structural or neurochemical changes with age. Finally, the ERN was smaller for those with high risk propensity and low empathy, while other components associated with error monitoring were not, which suggests that poor ACe function may be associated with the desire to engage in risky behaviors and the ERN may be influenced by the extent of individuals' concern with the outcome of events.

Autonomic and electrocortical indices of performance monitoring and source memory discrimination in older and younger adults

Reduced capacity for executive cognitive function and for the autonomic control of cardiac responsivity are both concomitants of the aging process. These may be linked through their mutual dependence on medial prefrontal function, but the specifics ofthat linkage have not been well explored. Executive functions associated with medial prefrontal cortex involve various aspects ofperformance monitoring, whereas centrally mediated autonomic functions can be observed as heart rate variability (HRV), i.e., variability in the length of intervals between heart beats. The focus for this thesis was to examine the degree to which the capacity for phasic autonomic adjustments to heart rate relates to performance monitoring in younger and older adults, using measures of electrocortical and autonomic activity. Behavioural performance and attention allocation during two age-sensitive tasks could be predicted by various aspects of autonomic control. For young adults, greater influence of the parasympathetic system on HRV was beneficial for learning unfamiliar maze paths; for older adults, greater sympathetic influence was detrimental to these functions. Further, these relationships were primarily evoked when the task required the construction and use of internalized representations of mazes rather than passive responses to feedback. When memory for source was required, older adults made three times as many source errors as young adults. However, greater parasympathetic influence on HRV in the older group was conducive to avoiding source errors and to reduced electrocortical responses to irrelevant information. Higher sympathetic predominance, in contrast, was associated with higher rates of source error and greater electrocortical responses tq non-target information in both groups. These relations were not seen for 11 errors associated with a speeded perceptual task, irrespective of its difficulty level. Overall, autonomic modulation of cardiac activity was associated with higher levels of performance monitoring, but differentially across tasks and age groups. With respect to age, those older adults who had maintained higher levels of autonomic cardiac regulation appeared to have also maintained higher levels of executive control over task performance.