Efficient Peer Selection in P2P JXTA-Based Platforms

Peer-reviewed

Collaborative group membership and access control for JXTA

Peer-reviewed

A Computer program for estimating population size by the removal method

A BASIC computer program (REMOVAL) was developed to compute in a VAXNMS environment all the calculations of the removal method for population size estimation (catch-effort method for closed populations with constant sampling effort). The program follows the maximum likelihood methodology,checks the failure conditions, applies the appropriate formula, and displays the estimates of population size and catchability, with their standard deviations and coefficients of variation, and two goodness-of-fit statistics with their significance levels. Data of removal experiments for the cyprinodontid fish Aphanius iberus in the Alt Emporda wetlands are used to exemplify the use of the program

Microcalcification evaluation in computer assisted diagnosis for digital mammography

In order to develop applications for z;isual interpretation of medical images, the early detection and evaluation of microcalcifications in digital mammograms is verg important since their presence is oftenassociated with a high incidence of breast cancers. Accurate classification into benign and malignant groups would help improve diagnostic sensitivity as well as reduce the number of unnecessa y biopsies. The challenge here is the selection of the useful features to distinguish benign from malignant micro calcifications. Our purpose in this work is to analyse a microcalcification evaluation method based on a set of shapebased features extracted from the digitised mammography. The segmentation of the microcalcificationsis performed using a fixed-tolerance region growing method to extract boundaries of calcifications with manually selected seed pixels. Taking into account that shapes and sizes of clustered microcalcificationshave been associated with a high risk of carcinoma based on digerent subjective measures, such as whether or not the calcifications are irregular, linear, vermiform, branched, rounded or ring like, our efforts were addressed to obtain a feature set related to the shape. The identification of the pammeters concerning the malignant character of the microcalcifications was performed on a set of 146 mammograms with their real diagnosis known in advance from biopsies. This allowed identifying the following shape-based parameters as the relevant ones: Number of clusters, Number of holes, Area, Feret elongation, Roughness, and Elongation. Further experiments on a set of 70 new mammogmms showed that the performance of the classification scheme is close to the mean performance of three expert radiologists, which allows to consider the proposed method for assisting the diagnosis and encourages to continue the investigation in the senseof adding new features not only related to the shape

Individual differences in control of language interference in late bilinguals are mainly related to general executive abilities

Background: Recent research based on comparisons between bilinguals and monolinguals postulates that bilingualism enhances cognitive control functions, because the parallel activation of languages necessitates control of interference. In a novel approach we investigated two groups of bilinguals, distinguished by their susceptibility to cross-language interference, asking whether bilinguals with strong language control abilities ('non-switchers") have an advantage in executive functions (inhibition of irrelevant information, problem solving, planning efficiency, generative fluency and self-monitoring) compared to those bilinguals showing weaker language control abilities ('switchers"). Methods: 29 late bilinguals (21 women) were evaluated using various cognitive control neuropsychological tests [e.g., Tower of Hanoi, Ruff Figural Fluency Task, Divided Attention, Go/noGo] tapping executive functions as well as four subtests of the Wechsler Adult Intelligence Scale. The analysis involved t-tests (two independent samples). Non-switchers (n = 16) were distinguished from switchers (n = 13) by their performance observed in a bilingual picture-naming task. Results: The non-switcher group demonstrated a better performance on the Tower of Hanoi and Ruff Figural Fluency task, faster reaction time in a Go/noGo and Divided Attention task, and produced significantly fewer errors in the Tower of Hanoi, Go/noGo, and Divided Attention tasks when compared to the switchers. Non-switchers performed significantly better on two verbal subtests of the Wechsler Adult Intelligence Scale (Information and Similarity), but not on the Performance subtests (Picture Completion, Block Design). Conclusions: The present results suggest that bilinguals with stronger language control have indeed a cognitive advantage in the administered tests involving executive functions, in particular inhibition, self-monitoring, problem solving, and generative fluency, and in two of the intelligence tests. What remains unclear is the direction of the relationship between executive functions and language control abilities.

A transformada de Fourier em basic

In this paper we describe three computer programs in Basic language about the Fourier transform (FFT) which are available in the Internet site http://artemis.ffclrp.usp.br/SoftwareE.htm (in English) or http://artemis.ffclrp.usp.br/softwareP.htm (in Portuguese) since October 1998. Those are addresses to the Web Page of our Laboratory of Organic Synthesis. The programs can be downloaded and used by anyone who is interested on the subject. The texts, menus and captions in the programs are written in English.

¿Estás en la onda? Aplicación de Praat a la enseñanza de la entonación

En este trabajo se pretende, por una parte, analizar cuáles son los métodos y programas existentes que se utilizan en la enseñanza de la entonación asistida por ordenador. Por otra parte, se pretende proporcionar algunas ideas para la aplicación del soporte visual en la enseñanza de la entonación

Profiles of Second Language Learners in Bilingual Education: A Comparative Study of the Characteristics of Finnish and American Students

The purpose of this comparative study is to profile second language learners by exploring the factors which have an impact on their learning. The subjects come from two different countries: one group comes from Milwaukee, US, and the other from Turku, Finland. The subjects have attended bilingual classes from elementary school to senior high school in their respective countries. In the United States, the subjects (N = 57) started in one elementary school from where they moved on to two high schools in the district. The Finnish subjects (N = 39) attended the same school from elementary to high school. The longitudinal study was conducted during 1994-2004 and combines both qualitative and quantitative research methods. A Pilot Study carried out in 1990-1991 preceded the two subsequent studies that form the core material of this research. The theoretical part of the study focuses first on language policies in the United States and Finland: special emphasis is given to the history, development and current state of bilingual education, and the factors that have affected policy-making in the provision of language instruction. Current language learning theories and models form the theoretical foundation of the research, and underpin the empirical studies. Cognitively-labeled theories are at the forefront, but sociocultural theory and the ecological approach are also accounted for. The research methods consist of questionnaires, compositions and interviews. A combination of statistical methods as well as content analysis were used in the analysis. The attitude of the bilingual learners toward L1 and L2 was generally positive: the subjects enjoyed learning through two languages and were motivated to learn both. The knowledge of L1 and parental support, along with early literacy in L1, facilitated the learning of L2. This was particularly evident in the American subject group. The American subjects’ L2 learning was affected by the attitudes of the learners to the L1 culture and its speakers. Furthermore, the negative attitudes taken by L1 speakers toward L2 speakers and the lack of opportunities to engage in activities in the L1 culture affected the American subjects’ learning of L2, English. The research showed that many American L2 learners were isolated from the L1 culture and were even afraid to use English in everyday communication situations. In light of the research results, a politically neutral linguistic environment, which the Finnish subjects inhabited, was seen to be more favorable for learning. The Finnish subjects were learning L2, English, in a neutral zone where their own attitudes and motivation dictated their learning. The role of L2 as a means of international communication in Finland, as opposed to a means of exercising linguistic power, provided a neutral atmosphere for learning English. In both the American and Finnish groups, the learning of other languages was facilitated when the learner had a good foundation in their L1, and the learning of L1 and L2 were in balance. Learning was also fostered when the learners drew positive experiences from their surroundings and were provided with opportunities to engage in activities where L2 was used.

Näkökulmia kielen oppimisen käytäntöihin. Turun yliopiston kielikeskus 30 vuotta - Perspectives on Language Learning in Practice. University of Turku Language Centre 30-year Celebration

Tämä julkaisu ilmestyy Turussa 18.–19.5.2009 järjestettävien valtakunnallisten kielikeskuspäivien yhteydessä. Turun yliopiston kielikeskus viettää samaan aikaan 30-vuotisjuhlaansa. Erään luokittelun mukaan 30–45-vuotias elää varsinaista keski-ikäänsä, kun taas joissakin katsotaan, että 28–35 vuoden ikä on vasta ns. jäsentymisen vaihe ja että varhainenkin keski-ikä sijoittuu vasta ikävuosiin 35–42. Voitaneen siis sanoa, että kielikeskus on ainakin ohittanut nuoruusvuodet ja on jäsentymässä tai siirtymässä keski-ikään. Tämä tuo mukanaan tietynlaista kypsymistä, itsensä varaan asettumista, imagon ja profiilin vakiintumista. Tähän kasvuun saattaa liittyä myös jonkinlainen aikuistumisen kriisi. Sen myötä kuitenkin ymmärrys lisääntyy ja oman paikan rakentaminen yliopistoyhteisössä voimistuu. Arvo- ja ajatusmaailmaan tulee uusia kehityspiirteitä: olemassaolon ja toiminnan syvemmät perustelut, illuusioiden väheneminen, hallinnan tunne, tyydytys onnistuneesta toiminnasta ja realistinen voiman tunto. Laitos esittäytyy julkaisussa 13 kirjoituksen välityksellä. Tekstit ovat sisällöltään ja käsittelytavaltaan hyvin erilaisia, mutta juuri sellaisina ne valottavat monipuolisesti laitoksen ja sen henkilökunnan toimintaa ja tuntemuksia. Kuvaukset valaisevat laitoksen erikoisluonnetta ja kuvailevat henkilökunnan erilaisia tehtäviä. Kielikeskus paljastuu dynaamisemmaksi ja heterogeenisemmaksi yksiköksi kuin ensi silmäyksellä saattaa luulla, mutta juuri siinä piilee sen voima ja rikkaus. Juhlakirjaan toivottiin kirjoituksia kielikeskuksen opetukseen tai toimintaan liittyvistä aiheista. Kirjaan sisältyy selontekojen ja kuvausten lisäksi muutamia tiukan tieteellisiä artikkeleita. Joukossa on myös joitakin esseitä, jotka koskettelevat kielen ja kulttuurin välisiä suhteita ja luovat katsauksia kielikeskuksen monikulttuuriseen arkeen. Useassa kirjoituksessa käsitellään kielipedagogisia ja -didaktisia kysymyksiä. Erityisesti tulee esiin kielikeskuksessa viime vuosina tehty uudistustyö opetuksen ja oppimisedellytysten parantamiseksi. Samalla kun muun muassa opetusteknologiaa ja kielen oppimisen käytäntöjä virtuaalisissa oppimisympäristöissä on kehitetty, opettajan rooli on muovautunut uudentyyppiseksi: perinteisen opetushenkilöstön ja muun henkilökunnan tehtävät ja toimenkuva ovat selvästi lähentyneet toisiaan. Tämä suuntaus on jatkunut jo kauan ja jatkunee tulevaisuudessakin. Kolmekymmentä viime vuotta ovat olleet yliopistossa erittäin nopean muutoksen aikaa. Tämä on näkynyt erityisesti kielikeskuksen toiminnan laajenemisessa ja kehityksessä, joissa tosin on ollut notkahduksiakin. Varsinkin nopea kansainvälistyminen, Euroopan yhteisön laajentuminen ja koko maailman avautuminen ovat tuoneet mukanaan uusia haasteita, joihin kielikeskus on heti tarttunut: kielivalikoimaa on laajennettava, kielitaitoa kohennettava ja erilaisia kulttuureja tunnettava ja ymmärrettävä syvällisemmin. Turun yliopiston kielikeskus pyrkii omalta osaltaan täyttämään nämä velvoitteet ja luomaan toiminnallaan mahdollisimman hyvät edellytykset yliopiston kansainvälistymiselle. Nämä seikat on otettu huomioon laitoksen toimintalinjojen suunnittelussa ja kehittämisessä. Kieli-ja viestintäopintojen rakenteiden uudistamista jatketaan yhteistyössä tiedekuntien kanssa. Opintojen valinnaisuutta ja vapaaehtoisuutta pyritään lisäämään sekä turvaamaan kielivalintojen monipuolisuus ja kieliosaamisen laajaalaisuus resurssien mukaan. Toimintaa kehitetään niin, että siinä otetaan entistä paremmin huomioon yhteiskunnan monikulttuuristuminen ja Euroopan komission tavoite, jonka mukaan jokaisen EU- kansalaisen tulisi osata oman äidinkielensä lisäksi vähintään kahta yhteisön kieltä. Samalla otetaan huomioon globalisaation tuomat uudet haasteet tukemalla tärkeimpien Euroopan yhteisön ulkopuolisten kielten opetusta (mm. venäjä, kiina, japani, arabia). Edelleen kielikeskus seuraa tarkoin keskustelua Suomen kielikoulutuspolitiikan perusteista ja tavoitteista ja ottaa toimintansa suunnittelussa huomioon valtakunnalliset suositukset Suomen kielikoulutuksen uudistamiseksi vastaamaan nykypäivän ja tulevaisuuden tarpeita ja tavoitteita. Se että kielikeskus on viime vuosina selvästikin vakiinnuttanut asemansa yliopiston strategisesti tärkeänä yksikkönä, ei tarkoita sitä, että nyt voitaisiin turvautua pelkästään vanhoihin toimintamalleihin ja rutiineihin. Päinvastoin, koko maailmassa, suomalaisessa yhteiskunnassa ja yliopistojen toiminnassa tapahtuneet ja tapahtuvat suuret muutokset edellyttävät kielikeskustoimintojen vireää kehittämistä ja uudistusmieltä. Laitos onkin ilmoittanut tulossopimuksessaan tukevansa opetuskokeiluja ja innovatiivisia ratkaisuja. Opettajajohtoisen opetuksen ohella on voimakkaasti kehitetty myös ohjattua itseopiskelua, monimuotoopetusta sekä vaihtoehtoisia ja uudentyyppisiä oppimismuotoja. Uutta opetusteknologiaa käytetään tehokkaasti hyväksi ja kehitetään edelleen. Opetuksessa ja ohjauksessa käytetään suomalaisten ja ulkomaisten opiskelijoiden työpanosta. Laitoksen suunnittelu- ja kehittämistyössä opiskelijat ovat toimineet viime vuosina aktiivisesti ja ansiokkaasti: yhteistyö ylioppilaskunnan kanssa toimii erinomaisesti, ja sitä on tarkoitus vielä tehostaa. Laitos on saanut runsaasti kiitosta korkealaatuisesta toiminnastaan: muun muassa v. 1998 ja 2008 Turun yliopiston vuoden opettajan palkinnon, v. 1999 Turun yliopiston parhaan koulutusyksikön palkinnon ja v. 2007 vuoden opintojaksopalkinnon. On toivottavaa, että tämä tuloksellinen työ jatkuisi ja entisestäänkin paranisi tulevina vuosina. Hyvät tulokset on saavutettu kovilla ponnistuksilla ja tiukalla sitoutumisella työhön. Aina se ei ole ollut aivan helppoa nopeiden muutosten myllerryksessä, tiukentuneessa resurssitilanteessa ja vaatimusten ja odotusten ristiriidoissa. Toivon, että pääosin hyvin sujunut yhteistyö yliopiston johdon, tiedekuntien ja opiskelijoiden kanssa sekä henkilökunnan keskuudessa voisi säilyä ja kehittyä ja että alkava vuosikymmen kielikeskuksen historiassa voisi olla entistä parempi. Hyvä yhteistyö on hyvien tulosten edellytys. Suurten uudistusten vuosi 2010 sisältää mahdollisuuden parempaan, mutta se on samalla myös riski ehkä hyvinkin paljon muuttuvassa toimintaympäristössä. Lainaan lopuksi roomalaisen historioitsijan Sallustiuksen sanat: Concordia res parvae crescunt, discordia maximae dilabuntur. Yksimielisyys saa pienetkin asiat kukoistamaan, eripura suuretkin tuhoaa. Turun yliopistolla on hyvä kielikeskus, jota kannattaa vaalia ja tukea. Kiitän kaikkia kirjoittajia ja juhlajulkaisun toimittajia Minna Maijalaa, Timo Hulkkoa ja Jane Honkaa tämän julkaisun synnystä. Samoin esitän kiitokset kielikeskuksen kirjallisen viestinnän lehtoreille, Markus Lahdelle ja Arja Lampiselle, jot ka ovat nähneet vaivaa tekstien kielellisinä korjaajina. Koko kielikeskuksen nykyistä ja aikaisempaa henkilökuntaa kiitän työstä, jota laitoksen hyväksi on tehty kuluneiden 30 vuoden aikana. Erityisen kiitoksen ansaitsee laitoksen juhlatoimikunta kaikista juhlavuoden järjestelyistä.

Role of Selected Spectral Attributes in the Perception of Synthetic Vowels

This thesis is an experimental study regarding the identification and discrimination of vowels, studied using synthetic stimuli. The acoustic attributes of synthetic stimuli vary, which raises the question of how different spectral attributes are linked to the behaviour of the subjects. The spectral attributes used are formants and spectral moments (centre of gravity, standard deviation, skewness and kurtosis). Two types of experiments are used, related to the identification and discrimination of the stimuli, respectively. The discrimination is studied by using both the attentive procedures that require a response from the subject, and the preattentive procedures that require no response. Together, the studies offer information about the identification and discrimination of synthetic vowels in 15 different languages. Furthermore, this thesis discusses the role of various spectral attributes in the speech perception processes. The thesis is divided into three studies. The first is based only on attentive methods, whereas the other two concentrate on the relationship between identification and discrimination experiments. The neurophysiological methods (EEG recordings) reveal the role of attention in processing, and are used in discrimination experiments, while the results reveal differences in perceptual processes based on the language, attention and experimental procedure.

Magneto-V1: um programa para o cálculo de correções diamagnéticas e de momentos magnéticos efetivos

A new computer program has been developed to help the users of force methods for magnetic moment determination. It provides a user-friendly interface for the calculation of corrected magnetic susceptibilities of paramagnetic materials and enables the user to simulate a number of chemical formulations for the sample under study. The program is written in the Perl scripting language and runs on a Unix platform.

Is there a relationship between bilingual language switching and executive functions in bilingualism? Introducing a within-group analysis approach

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.

Self-assessment of individual differences in language switching

Language switching is omnipresent in bilingual individuals. In fact, the ability to switch languages (code switching) is a very fast, efficient, and flexible process that seems to be a fundamental aspect of bilingual language processing. In this study, we aimed to characterize psychometrically self-perceived individual differences in language switching and to create a reliable measure of this behavioral pattern by introducing a bilingual switching questionnaire. As a working hypothesis based on the previous literature about code switching, we decomposed language switching into four constructs: (i) L1 switching tendencies (the tendency to switch to L1; L1-switch); (ii) L2 switching tendencies (L2-switch); (iii) contextual switch, which indexes the frequency of switches usually triggered by a particular situation, topic, or environment; and (iv) unintended switch, which measures the lack of intention and awareness of the language switches. A total of 582 SpanishCatalan bilingual university students were studied. Twelve items were selected (three for each construct). The correlation matrix was factor-analyzed using minimum rank factor analysis followed by oblique direct oblimin rotation. The overall proportion of common variance explained by the four extracted factors was 0.86. Finally, to assess the external validity of the individual differences scored with the new questionnaire, we evaluated the correlations between these measures and several psychometric (language proficiency) and behavioral measures related to cognitive and attentional control. The present study highlights the importance of evaluating individual differences in language switching using self-assessment instruments when studying the interface between cognitive control and bilingualism.

First- and second-language phonological representations in the mental lexicon

Performance-based studies on the psychological nature of linguistic competence can conceal significant differences in the brain processes that underlie native versus nonnative knowledge of language. Here we report results from the brain activity of very proficient early bilinguals making a lexical decision task that illustrates this point. Two groups of SpanishCatalan early bilinguals (Spanish-dominant and Catalan-dominant) were asked to decide whether a given form was a Catalan word or not. The nonwords were based on real words, with one vowel changed. In the experimental stimuli, the vowel change involved a Catalan-specific contrast that previous research had shown to be difficult for Spanish natives to perceive. In the control stimuli, the vowel switch involved contrasts common to Spanish and Catalan. The results indicated that the groups of bilinguals did not differ in their behavioral and event-related brain potential measurements for the control stimuli; both groups made very few errors and showed a larger N400 component for control nonwords than for control words. However, significant differences were observed for the experimental stimuli across groups: Specifically, Spanish-dominant bilinguals showed great difficulty in rejecting experimental nonwords. Indeed, these participants not only showed very high error rates for these stimuli, but also did not show an error-related negativity effect in their erroneous nonword decisions. However, both groups of bilinguals showed a larger correctrelated negativity when making correct decisions about the experimental nonwords. The results suggest that although some aspects of a second language system may show a remarkable lack of plasticity (like the acquisition of some foreign contrasts), first-language representations seem to be more dynamic in their capacity of adapting and incorporating new information. &

Computer-aided discovery of biological activity spectra for anti-aging and anti-cancer olive oil oleuropeins

Aging is associated with common conditions, including cancer, diabetes, cardiovascular disease, and Alzheimer"s disease. The type of multi‐targeted pharmacological approach necessary to address a complex multifaceted disease such as aging might take advantage of pleiotropic natural polyphenols affecting a wide variety of biological processes. We have recently postulated that the secoiridoids oleuropein aglycone (OA) and decarboxymethyl oleuropein aglycone (DOA), two complex polyphenols present in health‐promoting extra virgin olive oil (EVOO), might constitute a new family of plant‐produced gerosuppressant agents. This paper describes an analysis of the biological activity spectra (BAS) of OA and DOA using PASS (Prediction of Activity Spectra for Substances) software. PASS can predict thousands of biological activities, as the BAS of a compound is an intrinsic property that is largely dependent on the compound"s structure and reflects pharmacological effects, physiological and biochemical mechanisms of action, and specific toxicities. Using Pharmaexpert, a tool that analyzes the PASS‐predicted BAS of substances based on thousands of"mechanism‐ effect" and"effect‐mechanism" relationships, we illuminate hypothesis‐generating pharmacological effects, mechanisms of action, and targets that might underlie the anti‐aging/anti‐cancer activities of the gerosuppressant EVOO oleuropeins.